U.S. patent application number 11/760312 was filed with the patent office on 2007-12-20 for reciprocating compressor or pump and a portable tool powering system including a reciprocating compressor.
Invention is credited to Lloyd Dean Penner, Larry Alvin Schuetzle.
Application Number | 20070292282 11/760312 |
Document ID | / |
Family ID | 38801003 |
Filed Date | 2007-12-20 |
United States Patent
Application |
20070292282 |
Kind Code |
A1 |
Schuetzle; Larry Alvin ; et
al. |
December 20, 2007 |
RECIPROCATING COMPRESSOR OR PUMP AND A PORTABLE TOOL POWERING
SYSTEM INCLUDING A RECIPROCATING COMPRESSOR
Abstract
A reciprocating compressor or pump features a manifold arranged
not only to define a hollow interior for receiving fluid discharged
from a plurality of cylinders but also to define a base or frame on
which the cylinders are carried. Unique valves formed in part by
flexible material reduces the likelihood of fatigue and increases
efficiency by retaining less heat relative to conventional reed
valves. A compressor or pump mounted at an end of a handle
extending parallel to a motor housing likewise extending from the
compressor or pump provides an easy to carry portable assembly. A
fan mounted between a motor and a compressor pulls air through the
compressor inlet to both cool the motor and feed the compressor. A
portable tool system powers both pneumatic and electric tools.
Connecting rod structures for radial compressors or pumps provide
improved strength and easier assembly.
Inventors: |
Schuetzle; Larry Alvin;
(Calgary, CA) ; Penner; Lloyd Dean; (Calgary,
CA) |
Correspondence
Address: |
ADE & COMPANY INC.
2157 Henderson Highway
WINNIPEG
MB
R2G1P9
CA
|
Family ID: |
38801003 |
Appl. No.: |
11/760312 |
Filed: |
June 8, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60804216 |
Jun 8, 2006 |
|
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Current U.S.
Class: |
417/273 |
Current CPC
Class: |
H02J 7/0063 20130101;
F04B 53/16 20130101; F04B 39/121 20130101; F04B 35/00 20130101;
F04B 35/04 20130101; F04B 41/06 20130101; F04B 1/0404 20130101;
F04B 1/0421 20130101; F04B 39/0005 20130101; F04B 39/10 20130101;
F04B 35/06 20130101; F04B 1/0439 20130101; F04B 53/14 20130101;
F04B 1/0452 20130101; F04B 39/127 20130101; H01B 7/0072 20130101;
F04B 27/053 20130101; F16L 37/23 20130101; F04B 1/053 20130101;
F04B 39/122 20130101; F04B 39/066 20130101; F04B 39/0022 20130101;
F04B 39/123 20130101; F04B 39/0094 20130101 |
Class at
Publication: |
417/273 |
International
Class: |
F04B 1/04 20060101
F04B001/04 |
Claims
1. A reciprocating compressor or pump comprising: a hollow
cylinder; a piston mounted within the cylinder for limited
reciprocal movement therealong; a drive system connected to the
piston and operable to drive the reciprocal movement thereof;
intake and exhaust valves associated with the cylinder and operable
to allow passage of fluid into the cylinder from a fluid supply
outside the cylinder and subsequent discharge of the fluid from the
cylinder under exertion of pressure on the fluid in the cylinder by
the piston during movement toward a fully extended position thereof
furthest from the drive system; wherein the intake valve comprises:
a valve seat comprising a projection extending into a space within
the hollow cylinder between a sealing engagement of the piston with
the cylinder and a distal end of the cylinder opposite an open end
thereof through which the piston and the drive system are
connected; a passage extending through the valve seat with an
opening of the passage being defined on the projection to fluidly
communicate the fluid supply outside the cylinder with the space
within the hollow cylinder between the sealing engagement of the
piston with the cylinder and the distal end of the cylinder; and a
resilient band disposed circumferentially about the projection, the
band being resiliently stretchable about the projection by a
difference in pressure between the fluid supply outside the
cylinder and the space within the hollow cylinder between the
sealing engagement of the piston with the cylinder and the distal
end of the cylinder.
2. The reciprocating compressor or pump according to claim 1
wherein the resilient band is disposed in a circumferential recess
in the projection.
3. The reciprocating compressor or pump according to claim 2
wherein the circumferential recess in the projection is tapered
from an outermost periphery thereof.
4. The reciprocating compressor or pump according to claim 3
wherein the resilient band is tapered from an outer surface thereof
to an inner surface thereof.
5. The reciprocating compressor or pump according to claim 2
wherein a depth of the circumferential recess is sufficient to
prevent complete withdrawal of the resilient band from the
circumferential recess under stretching by the difference in
pressure.
6. The reciprocating compressor or pump according to claim 1
wherein the valve seat is formed on the piston with the passage
extending through the piston to fluidly communicate opposite sides
of the sealing engagement of the piston with the cylinder.
7. The reciprocating compressor or pump according to claim 1
wherein the valve seat is formed on the distal end of the cylinder
with the projection extending into the space within the hollow
cylinder from the distal end thereof.
8. The reciprocating compressor or pump according to claim 1
wherein the valve seat is formed on a cylinder head sealed to the
distal end of the cylinder with the passage extending through the
cylinder head to fluidly communicate opposite sides of a sealing
engagement of the cylinder head with the cylinder.
9. A reciprocating compressor or pump comprising: a cylinder liner
defining a cylindrical bore and a piston sealed to the cylinder
liner within the cylindrical bore for reciprocal movement
therealong; a drive system connected to the piston and operable to
drive the reciprocal movement thereof; and intake and exhaust
valves associated with the cylinder and operable to allow passage
of fluid into the cylindrical bore from a fluid supply outside the
cylinder liner and subsequent discharge of the fluid from the
cylindrical bore into a receiver under exertion of pressure on the
fluid in the cylinder by the piston during movement toward a fully
extended position thereof furthest from the drive system; the
exhaust valve comprising at least one exhaust port extending
through a wall of the cylinder liner and a resilient band disposed
circumferentially about the cylinder liner, the band being
resiliently stretchable about the respective cylinder liner by
passage of the fluid through the exhaust port from the cylindrical
bore by the under the pressure exerted on the fluid by the piston;
and the receiver being sealed about the cylinder liner to enclose
the resilient band and stretching of the resilient band within the
receiver allowing flow of the fluid from the cylindrical bore into
the receiver through the at least one exhaust port.
10. The reciprocating compressor or pump according to claim 9
comprising a plurality of cylinder liners about which the receiver
is sealed to receive fluid from the cylindrical bore of each
cylinder liner.
11. The reciprocating compressor or pump according to claim 9
wherein the resilient band is disposed in a circumferential recess
in the wall of the cylinder liner.
12. The reciprocating compressor or pump according to claim 11
wherein the circumferential recess in the wall of the cylinder
liner is tapered from an outermost periphery thereof toward the
cylindrical bore.
13. The reciprocating compressor or pump according to claim 12
wherein the resilient band is tapered from an outer surface thereof
to an inner surface thereof.
14. The reciprocating compressor or pump according to claim 12
wherein a depth of the circumferential recess is sufficient to
prevent complete withdrawal of the resilient band from the
circumferential recess under stretching by the compressed gas.
15. A reciprocating compressor or pump comprising: a hollow
cylinder; a piston disposed within an interior of the hollow
cylinder and sealed to the hollow cylinder for reciprocal movement
therealong; a drive system connected to the piston and operable to
drive the reciprocal movement thereof along the hollow cylinder;
and intake and exhaust valves associated with the hollow cylinder
and operable to allow passage of fluid into the cylinder, and
subsequent discharge of the fluid therefrom under exertion of
pressure on the fluid by the piston during movement toward an
extended position thereof furthest from the drive system; at least
one of the intake and exhaust valves comprising: a valve port
communicating a fluid supply outside the hollow cylinder with a
space within the hollow cylinder between a sealing engagement of
the piston with the cylinder and a distal end of the cylinder
opposite an open end thereof through which the piston and the drive
system are connected; and a flap comprising a fixed portion secured
at a surface surrounding an opening of the valve port on one side
thereof and a movable portion connected to the fixed portion by a
flexible portion, the movable portion having greater rigidity than
the flexible portion; the flexible portion of the flap between the
fixed and movable portions thereof being bendable in response to
pressure differences between the space within the hollow cylinder
and the fluid supply outside the hollow cylinder to move the
movable portion between a closed position sealingly covering the
opening of the valve port and an open position at least partially
lifted from the opening of the valve port to allow fluid flow
therethough.
16. The reciprocating compressor or pump according to claim 15
wherein the at least one of the intake and exhaust valves includes
the intake valve, the valve port of the intake valve extending
through the piston across the sealing engagement of the piston with
the hollow cylinder and the flap being secured to a face of the
piston on a side of the sealing engagement opposite the drive
system.
17. The reciprocating compressor or pump according to claim 15
further comprising a second port surrounded by the surface and
second movable and flexible portions of the flap likewise arranged
to seal off and open the second port in response to pressure
differences between the space within the hollow cylinder and the
fluid supply outside the hollow cylinder.
18. The reciprocating compressor or pump according to claim 17
wherein the valve port and the second port, the movable portion and
the second movable portion of the flexible flap, and the flexible
portion and the second flexible portion are symmetric across the
fixed portion of the flap.
19. The reciprocating compressor or pump according to claim 15
further comprising a seal secured to the surface to extend around
the valve port and seal with the moveable portion of the flap in
the closed position.
20. The reciprocating compressor or pump according to claim 15
wherein the movable portion comprises an integral extension of the
flexible portion and a piece of material of greater rigidity than
the flexible portion secured to the integral extension of the
flexible portion.
21. The reciprocating compressor according to claim 15 wherein the
piece of material comprises metal.
22. The reciprocating compressor according to claim 21 wherein the
flexible flap comprises rubber.
Description
[0001] This application claims the benefit under 35 U.S.C. 119(e)
of U.S. provisional application Ser. No. 60/804,216, filed Jun. 8,
2006.
FIELD OF THE INVENTION
[0002] This invention relates to compressors and pumps, and more
particularly to cylinder and piston based reciprocating compressors
and pumps.
BACKGROUND OF THE INVENTION
[0003] The user of a pneumatic tool requiring a steady source of
compressed air for operation is usually limited in mobility by a
length of air hose connected to an air compressor that is
stationary, or at least limited in mobility. A conventional air
compressor is often limited in mobility due to a large tank for
storing compressed air, a non-electric motor driving the compressor
that may emit harmful gases and requires a fuel source that adds
weight and dimension, or an electric motor requiring connection to
a fixed power source such as an AC outlet.
[0004] U.S. Pat. Nos. 6,692,239 and 6,589,024 of Nishikawa et al.
and U.S. Pat. No. 5,030,065 of Baumann teach radially disposed
reciprocating compression mechanisms, opposed pairs of which are
each linked by a respective yoke mechanism to drive reciprocation
thereof.
[0005] Japanese Patent Abstract Publication No. 59190486 teaches a
reciprocating air compressor having its cylinders secured radially
on the polygonal peripheral wall of a crankcase to reduce the
front-to-rear length of the compressor. Conventional connecting rod
assemblies used in such radial cylinder arrangements typically use
pins to pivotally connect a master connecting rod to other
connecting rods. Such pins may prematurely fail when significantly
reduced in scale for use in a compact portable device and may
involve a significant number of assembly steps to complete
connection between the master connecting rod and all of the
pistons.
[0006] Battery-powered portable air compressors having either small
tanks or no tanks at all have been developed in an attempt to avoid
the mobility limitations of conventional compressors listed above.
However, such battery-powered types of compressors typically do not
provide enough airflow to be useful for powering pneumatic tools,
which require relatively high amounts of air pressure provided on a
relatively continuous basis for optimal operation. These
compressors are typically reciprocating compressors that feature
only a single piston/cylinder arrangement in the interest of
keeping the compressors relatively small for the purpose of
improving portability.
[0007] International Publication Number WO 01/29421 teaches a
battery powered portable compressor system featuring a two-cylinder
compressor, of the type described in U.S. Pat. No. 4,715,787
mounted on a belt and storing compressed air within a hose
connecting the compressor to a pneumatic tool.
[0008] U.S. Pat. No. 3,931,554 of Spentzas teaches a two-piston
reciprocating motor compressor that, in the embodiment of FIG. 9,
is battery operated.
[0009] U.S. Patent Application Publication Number 2002/0158102 of
Patton et al. teaches a portable pneumatic tool having an onboard
single-piston compressor assembly that can be powered by a
detachable battery and a portable single-piston compressor assembly
that can be borne by a user to power a pneumatic tool.
[0010] U.S. Pat. No. 6,089,835 of Suzuura et al. teaches a portable
single-piston compressor having a motor and a power transmitting
mechanism supported in a two-piece housing and an air tank defined
by an outer surface of the second housing and an inside surface of
a third housing mounted to the second housing.
[0011] U.S. Patent Application Publication number 2005/0214136 of
Tsai teaches a portable compressor system including a knapsack
divided into two chambers, one of which contains a DC motor, an air
cylinder, an air storage flask, a pressure switch and a quick
connector, and the other containing a battery and a control
box.
[0012] U.S. Pat. No. 3,961,868 teaches a small compressor having a
single cylinder with a wobble type piston having the intake port
valve provided on the piston head to introduce air from the crank
case into the cylinder.
[0013] A worker using both portable electric tools and pneumatic
tools powered by a portable compressor at one job site typically
must carry two or more separate battery packs, as the battery
packs.
[0014] U.S. Pat. No. 5,095,259 teaches a system for operating a
plurality of different DC power tools and appliances one-at-a-time.
However, the use of such a system to power both an electric tool
and a portable compressor for a pneumatic tool involves the running
of two separate power delivery lines, an electrical cord from the
battery pack for connection to the electric tool or the compressor
and an air hose from the compressor to the pneumatic tool.
[0015] Conventional compressors and pumps often use reed valves
using a thin, flexible strip of metal or fiberglass fixed at one
end and bendable to open and close over a port in response to
differences in pressure on opposite sides of the valve. These
valves may break off or fail to seat properly after repeated
exposure to the bending stresses experienced in their operation.
Metal reeds also retain heat which may be considered wasted energy
and may corrode over time with exposure to moisture.
[0016] Conventional pumps used, for example, to withdraw
production-inhibiting water from oil and gas wells, may fail
relatively quickly when run continuously with exposure to brackish
water or other fluids containing abrasive particulate material such
as sulfur or sand. More particularly, the reeds in such a pump may
wear or corrode at an increased rate as a result of such
exposure.
SUMMARY OF THE INVENTION
[0017] According to a first aspect of the invention there is
provided a reciprocating compressor or pump comprising:
[0018] a plurality of cylinder liners each having a cylindrical
bore therethrough;
[0019] a plurality of pistons each sealed to a respective one of
the cylinder liners within the cylindrical bore thereof;
[0020] a drive system coupled to each piston to effect reciprocal
motion thereof along the cylindrical bore of the respective
cylinder liner between a fully extended position furthest from the
drive system and a fully retracted position nearest the drive
system;
[0021] an intake valve and an exhaust valve associated with each
cylinder liner, the intake valve being arranged to open as the
piston retracts toward the fully retracted position and to close as
the piston extends away therefrom and the exhaust valve being
arranged to open as the piston extends toward the fully extended
position and to close as the piston retracts away therefrom;
[0022] a manifold having a hollow interior fluidly communicating
with the cylindrical bore of each cylinder liner when the intake
valve associated therewith is open;
[0023] wherein the plurality of cylinder liners and the drive
system are carried by the manifold.
[0024] Preferably the cylinder liners are disposed in a common
plane and extend radially about an axis normal to the common
plane.
[0025] The cylinder liners may be mounted to an external surface of
the manifold, in which case each cylinder liner preferably extends
along a plane in which the external surface of the manifold
lies.
[0026] Preferably the manifold on which the cylinder liners are
carried is substantially rigid.
[0027] The manifold may be sealed to an outer surface of each
cylinder liner to enclose a portion thereof on which the exhaust
valve associated therewith is defined.
[0028] The hollow interior of the manifold may define an annular
space extending about the axis to communicate with each exhaust
valve.
[0029] Each cylinder liner may be disposed at least partially
within the hollow interior of the manifold with each exhaust valve
disposed within the hollow interior of the manifold to control flow
between the cylindrical bore of the cylinder liner and the
surrounding hollow interior. In this instance, each exhaust valve
preferably comprises at least one exhaust port extending through
the cylinder liner and a resilient band disposed circumferentially
about the cylinder liner, the band being resiliently stretchable
about the respective cylinder liner by fluid pressure exerted on
the band through the exhaust port during movement of the piston
toward the fully extended position.
[0030] The cylinder liners may project from a crank chamber, in
which the drive system is at least partially disposed, into the
hollow interior of the manifold. In this instance, the crank
chamber may be surrounded by an annular wall with the hollow
interior of the manifold defining an annular space extending about
the annular wall to communicate with the cylindrical bore of each
cylinder liner, which projects radially from the annular wall into
the hollow interior of the manifold, when the respective exhaust
valve is open.
[0031] According to a second aspect of the invention, there is
provided a portable compressor or pump assembly comprising:
[0032] a carrying handle having opposite first and second ends;
[0033] a motor supported on the carrying handle and comprising a
drive shaft extending therealong; and
[0034] a reciprocating compressor or pump supported on the carrying
handle at the first end thereof and connected to the driveshaft of
the motor for driven operation thereby.
[0035] There may be provided a power delivery device supported at
the second end of the carrying handle and connected to the motor
for powered operation thereof. In this instance, the power delivery
device is preferably manually removable and there is preferably
provided a conduit extending along the carrying handle in fluid
communication with a receiver into which fluid is delivered by
operation of the reciprocating compressor or pump, and a pressure
switch in fluid communication with the conduit at the end thereof
nearest the second end of the carrying handle for electrical
connection to the power delivery device and motor to control
operation of the motor in response to pressure measured within the
conduit and receiver.
[0036] Alternatively, there may be provided a second reciprocating
compressor or pump supported on the carrying handle at the second
end thereof and connected to the driveshaft of the motor for driven
operation thereby. In this instance, and there is preferably
provided a power delivery device connected to the motor for powered
operation thereof, the power delivery device defining a base on
which the carrying handle, the motor and the reciprocating
compressors or pumps are mounted; and a conduit extending along the
carrying handle to fluidly connect two receivers into which fluid
is delivered by operation of the reciprocating compressors or
pumps, and an outlet in fluid communication with the conduit and
the two receivers to define a common discharge of the two
reciprocating compressors or pumps.
[0037] Preferably the conduit is defined by a hollow interior of
the carrying handle.
[0038] Preferably the reciprocating compressor or pump comprises a
plurality of cylinders spaced about, and each extending radially
relative to, an axis of the drive shaft within a common plane.
[0039] According to a third aspect of the invention there is
provided a reciprocating compressor or pump comprising:
[0040] a housing defining a crank chamber;
[0041] a crankshaft comprising a shaft arranged for driven rotation
about an axis and a crank pin carried on the shaft eccentric to the
axis within the crank chamber;
[0042] a plurality of cylinders arranged to extend radially about
the axis outward from the crank chamber; and
[0043] a piston and rod structure comprising, [0044] a central body
pivotally secured to the crank pin for relative rotation between
the central body and the crank pin about an eccentric axis defined
by the crank pin eccentric to the axis about which the shaft is
rotatable; [0045] a plurality of connecting rods each having a
first connection at one end thereof to the central body and
extending outward therefrom to a second connection, the first
connection of each connecting rod allowing generally pivotal motion
thereof relative to the central body; and [0046] a plurality of
pistons each connected to a the second connection of a respective
connecting rod and being sealed against an interior wall of a
respective cylinder, the second connection of each connecting rod
allowing generally pivotal motion thereof relative to the
piston;
[0047] and intake and exhaust valves associated with each cylinder
and arranged to allow passage of fluid into the cylinder, and
subsequent discharge of the fluid therefrom under exertion of
pressure on the fluid by the piston during movement thereof along
the cylinder away from the shaft under driven rotation thereof;
[0048] wherein each connecting rod is integral with at least one of
the central body and the respective piston and forms a flexible
connection therewith.
[0049] Preferably the central body and the connecting rods are
integral.
[0050] Preferably the central body and the connecting rods comprise
integral plastic.
[0051] Preferably each connecting rod is integral with the
respective piston.
[0052] Preferably each connecting rod and the respective piston
comprise integral plastic.
[0053] Preferably there is provided a motor coupled to the
driveshaft and operable for driven rotation thereof.
[0054] According to a further aspect of the invention there is
provided a reciprocating compressor or pump comprising:
[0055] a housing defining a crank chamber;
[0056] a crankshaft comprising a shaft arranged for driven rotation
about an axis and a crank pin carried on the shaft eccentric to the
axis within the crank chamber;
[0057] a plurality of cylinders arranged to extend radially about
the axis outward from the crank chamber; and
[0058] a connecting rod structure comprising: [0059] a central body
pivotally secured to the crank pin for relative rotation between
the central body and the crank pin about an eccentric axis defined
by the crank pin eccentric to the axis about which the shaft is
rotatable; and [0060] a plurality of connecting rods connected to
the central body, each connecting rod extending outward from the
central body into a respective cylinder to pivotally support a
piston at the end of the connecting rod opposite the flexible
connection sealed against an interior wall of the cylinder; [0061]
the body having a plurality of peripheral keyways parallel to and
spaced about the eccentric axis, the keyways receiving ends of all
but one of the connecting rods, the keyways and each of the all but
one connecting rods being arranged to prevent separation thereof
while allowing limited relative pivoting therebetween, within a
plane normal to the eccentric axis;
[0062] and intake and exhaust valves associated with each cylinder
and arranged to allow passage of fluid into the cylinder, and
subsequent discharge of the fluid therefrom under exertion of
pressure on the fluid by the piston during movement thereof along
the cylinder away from the shaft under driven rotation thereof.
[0063] Preferably a wall of each peripheral keyway comprises an
arcuate portion spanning over 180 degrees to form a mouth having a
width less than the diameter of the arcuate portion.
[0064] Preferably each of the all but one of the connecting rods
comprises a rounded end having a diameter greater than the width of
the mouth of a respective one of the peripheral keyways, and a stem
having a width less than the diameter of the rounded end and
extending from the rounded end through the mouth of the respective
one of the peripheral keyways away from the central body of the
connecting rod structure.
[0065] Preferably the arcuate portion of the wall of each
peripheral keyway defines said wall entirely.
[0066] According to a fifth aspect of the invention there is
provided a reciprocating compressor or pump comprising:
[0067] a hollow cylinder;
[0068] a piston mounted within the cylinder for limited reciprocal
movement therealong;
[0069] a drive system connected to the piston and operable to drive
the reciprocal movement thereof:
[0070] intake and exhaust valves associated with the cylinder and
operable to allow passage of fluid into the cylinder from a fluid
supply outside the cylinder and subsequent discharge of the fluid
from the cylinder under exertion of pressure on the fluid in the
cylinder by the piston during movement toward a fully extended
position thereof furthest from the drive system;
[0071] wherein the intake valve comprises: [0072] a valve seat
comprising a projection extending into a space within the hollow
cylinder between a sealing engagement of the piston with the
cylinder and a distal end of the cylinder opposite an open end
thereof through which the piston and the drive system are
connected; [0073] a passage extending through the valve seat with
an opening of the passage being defined on the projection to
fluidly communicate the fluid supply outside the cylinder with the
space within the hollow cylinder between the sealing engagement of
the piston with the cylinder and the distal end of the cylinder;
and [0074] a resilient band disposed circumferentially about the
projection, the band being resiliently stretchable about the
projection by a difference in pressure between the fluid supply
outside the cylinder and the space within the hollow cylinder
between the sealing engagement of the piston with the cylinder and
the distal end of the cylinder.
[0075] Preferably the resilient band is disposed in a
circumferential recess in the projection.
[0076] Preferably the circumferential recess in the projection is
tapered from an outermost periphery thereof.
[0077] Preferably the resilient band is tapered from an outer
surface thereof to an inner surface thereof.
[0078] Preferably a depth of the circumferential recess is
sufficient to prevent complete withdrawal of the resilient band
from the circumferential recess under stretching by the difference
in pressure.
[0079] The valve seat may be formed on the piston with the passage
extending through the piston to fluidly communicate opposite sides
of the sealing engagement of the piston with the cylinder.
[0080] Alternatively the valve seat may be formed on the distal end
of the cylinder with the projection extending into the space within
the hollow cylinder from the distal end thereof. In this instance,
the valve seat may be formed on a cylinder head sealed to the
distal end of the cylinder with the passage extending through the
cylinder head to fluidly communicate opposite sides of a sealing
engagement of the cylinder head with the cylinder.
[0081] According to a sixth aspect of the invention there is
provided a reciprocating compressor or pump comprising:
[0082] a cylinder liner defining a cylindrical bore and a piston
sealed to the cylinder liner within the cylindrical bore for
reciprocal movement therealong;
[0083] a drive system connected to the piston and operable to drive
the reciprocal movement thereof; and
[0084] intake and exhaust valves associated with the cylinder and
operable to allow passage of fluid into the cylindrical bore from a
fluid supply outside the cylinder liner and subsequent discharge of
the fluid from the cylindrical bore into a receiver under exertion
of pressure on the fluid in the cylinder by the piston during
movement toward a fully extended position thereof furthest from the
drive system;
[0085] the exhaust valve comprising at least one exhaust port
extending through a wall of the cylinder liner and a resilient band
disposed circumferentially about the cylinder liner, the band being
resiliently stretchable about the respective cylinder liner by
passage of the fluid through the exhaust port from the cylindrical
bore by the under the pressure exerted on the fluid by the piston;
and
[0086] the receiver being sealed about the cylinder liner to
enclose the resilient band and stretching of the resilient band
within the receiver allowing flow of the fluid from the cylindrical
bore into the receiver through the at least one exhaust port.
[0087] Preferably there is provided a plurality of cylinder liners
about which the receiver is sealed to receive fluid from the
cylindrical bore of each cylinder liner.
[0088] Preferably the resilient band is disposed in a
circumferential recess in the wall of the cylinder liner.
[0089] Preferably the circumferential recess in the wall of the
cylinder liner is tapered from an outermost periphery thereof
toward the cylindrical bore.
[0090] Preferably the resilient band is tapered from an outer
surface thereof to an inner surface thereof.
[0091] Preferably a depth of the circumferential recess is
sufficient to prevent complete withdrawal of the resilient band
from the circumferential recess under stretching by the compressed
gas.
[0092] According to a seventh aspect of the invention there is
provided reciprocating compressor or pump comprising:
[0093] a hollow cylinder;
[0094] a piston disposed within an interior of the hollow cylinder
and sealed to the hollow cylinder for reciprocal movement
therealong;
[0095] a drive system connected to the piston and operable to drive
the reciprocal movement thereof along the hollow cylinder; and
[0096] intake and exhaust valves associated with the hollow
cylinder and operable to allow passage of fluid into the cylinder,
and subsequent discharge of the fluid therefrom under exertion of
pressure on the fluid by the piston during movement toward an
extended position thereof furthest from the drive system;
[0097] at least one of the intake and exhaust valves comprising:
[0098] a valve port communicating a fluid supply outside the hollow
cylinder with a space within the hollow cylinder between a sealing
engagement of the piston with the cylinder and a distal end of the
cylinder opposite an open end thereof through which the piston and
the drive system are connected; and [0099] a flap comprising a
fixed portion secured at a surface surrounding an opening of the
valve port on one side thereof and a movable portion connected to
the fixed portion by a flexible portion, the movable portion having
greater rigidity than the flexible portion; [0100] the flexible
portion of the flap between the fixed and movable portions thereof
being bendable in response to pressure differences between the
space within the hollow cylinder and the fluid supply outside the
hollow cylinder to move the movable portion between a closed
position sealingly covering the opening of the valve port and an
open position at least partially lifted from the opening of the
valve port to allow fluid flow therethough.
[0101] The at least one of the intake and exhaust valves may
include the intake valve, the valve port of the intake valve
extending through the piston across the sealing engagement of the
piston with the hollow cylinder and the flap being secured to a
face of the piston on a side of the sealing engagement opposite the
drive system.
[0102] There may be provided a second port surrounded by the
surface and second movable and flexible portions of the flap
likewise arranged to seal off and open the second port in response
to pressure differences between the space within the hollow
cylinder and the fluid supply outside the hollow cylinder. In this
instance, preferably the valve port and the second port, the
movable portion and the second movable portion of the flexible
flap, and the flexible portion and the second flexible portion are
symmetric across the fixed portion of the flap.
[0103] Preferably there is provided a seal secured to the surface
to extend around the valve port and seal with the moveable portion
of the flap in the closed position.
[0104] Preferably the movable portion comprises an integral
extension of the flexible portion and a piece of material of
greater rigidity than the flexible portion secured to the integral
extension of the flexible portion.
[0105] Preferably the piece of material comprises metal.
[0106] Preferably the flexible flap comprises rubber.
[0107] According to an eighth aspect of the invention there is
provided a portable tool powering system comprising:
[0108] a portable air compressor unit comprising an air compressor
and an electric motor connected thereto for driven operation
thereof;
[0109] a battery pack comprising at least one battery and being
connectable to the motor to selectively supply power thereto;
and
[0110] a power delivery assembly comprising: [0111] an air hose
connected the air compressor and having a pneumatic tool connector
at an end of the air hose opposite the air compressor; and [0112]
electrical conductors connected to the battery pack and extending
along the air hose toward the end thereof opposite the air
compressor, the electrical conductors having an electric tool
connector at an end thereof opposite the battery pack;
[0113] an end of the power delivery assembly opposite the battery
pack and the portable air compressor thereby being connectable to
pneumatic or electric tools.
[0114] Preferably the electrical conductors are disposed within a
common cover.
[0115] The battery pack, motor and electrical conductors may be
wired to selectively deliver electricity to only one of the motor
and the electric tool connection at any one time.
[0116] Preferably the battery pack comprises a rechargeable
battery.
[0117] The pneumatic tool connector and electric tool connector may
be defined by a single quick connect unit connectable one-at-a-time
to pneumatic and electric tools. In this instance, there may be
provided a pneumatic tool and an electric tool, each tool having
mounted thereon a quick connect component having an air passageway
and a pair of electrical contacts, the quick connect component of
the pneumatic tool having the air passageway thereof in fluid
communication with an inlet of an air powered drive system of the
pneumatic tool and the quick connect component of the electric tool
having the electrical contacts thereof electrically connected to an
electric powered drive system of the electric tool.
[0118] According to a ninth aspect of the invention, there is
provided a reciprocating compressor comprising:
[0119] a crank chamber:
[0120] a crankshaft supported for rotation within the crank
chamber;
[0121] a motor having a driveshaft coupled to the crankshaft to
drive rotation thereof within the crank chamber;
[0122] at least one cylinder projecting from the crank chamber with
an open end of each cylinder fluidly communicating with the crank
chamber;
[0123] a piston disposed within each cylinder and sealed thereto,
the piston being connected to the crankshaft for reciprocating
motion within the cylinders the piston moving away from the
crankshaft during a compression stroke and toward the crankshaft
during an intake stroke;
[0124] an intake valve associated with each cylinder in fluid
communication with the crank chamber, the intake valve being
operable to open during the intake stroke in response to a pressure
difference between the crank chamber and a space within the
cylinder between the piston and an end of the cylinder opposite the
open end thereof communicating with the crank chamber to allow
fluid to flow into said space during the intake stroke;
[0125] an exhaust valve associated with each cylinder and operable
to open during the compression stroke to facilitate discharge of
the fluid out of said space within the cylinder during the
compression stroke; and
[0126] a fan mounted between the motor and the at least one
cylinder, the fan being in fluid communication with the crank
chamber and operable to induce fluid flow into the crank chamber
through an inlet thereof, a first portion of the fluid flow being
drawn into each cylinder during intake stroke of the piston therein
and a second portion of the fluid flow being drawn by operation of
the fan past the fan along the driveshaft to the motor.
[0127] Preferably the motor and the fan are mounted within a common
housing open at one end to the crank chamber and having at least
one opening in the housing on a side of the motor opposite the
crank chamber for exit of the second portion of the fluid flow
after passing the motor.
[0128] Preferably the fan is carried on the driveshaft for driven
rotation by the motor.
[0129] Preferably the housing is cylindrical to form an annular
peripheral wall around the motor, the second portion of the motor
flowing past the motor between the motor and the peripheral wall
closing thereabout.
[0130] Preferably the at least one cylinder comprises a plurality
of cylinders spaced about and radial to a rotational axis of the
crankshaft within a common plane normal to the rotational axis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0131] In the accompanying drawings, which illustrate a exemplary
embodiments of the present invention:
[0132] FIG. 1 is a perspective view of a first embodiment portable
compressor showing an openable side thereof.
[0133] FIG. 2 is a perspective view of the first embodiment
portable compressor showing a driving side thereof.
[0134] FIG. 3 is a perspective view of the first embodiment
portable compressor with an electric motor operatively connected to
the driving side thereof.
[0135] FIG. 4 is a perspective view of the first embodiment
portable compressor with a removable cover thereof removed.
[0136] FIG. 5 is a perspective view of the first embodiment
portable compressor with the removable cover removed and a gas
compressor and crank cheek exploded for illustration.
[0137] FIG. 6 is a perspective view of the crank cheeks of the
first embodiment portable compressor.
[0138] FIG. 7 is a partial perspective view of a cylinder liner of
the first embodiment portable compressor showing a valve end of the
cylinder liner.
[0139] FIGS. 8A, 8B and 8C are perspective views of a cylinder head
of the first embodiment portable compressor.
[0140] FIG. 9 is a perspective view of select unassembled
components of a connecting rod structure of the first embodiment
portable compressor.
[0141] FIG. 10 is a perspective view of a second embodiment
portable compressor with a top half of a receiver housing and a lid
of a crank housing removed for illustration.
[0142] FIG. 11 is a top plan view of the second embodiment portable
compressor.
[0143] FIG. 11A is a cross sectional view of the second embodiment
portable compressor as taken along line A-A of FIG. 11.
[0144] FIG. 11B is a close-up view of a portion of the second
embodiment portable compressor indicated by circle B of FIG.
11A.
[0145] FIG. 12 is a side elevational view of the second embodiment
portable compressor.
[0146] FIG. 13 is a perspective view of a bottom half of the
receiver housing of the second embodiment portable compressor.
[0147] FIG. 13A is a top plan view of the bottom half of the
receiver housing of the second embodiment portable compressor.
[0148] FIG. 13B is a cross sectional view of the bottom half of the
receiver housing of the second embodiment compressor as taken along
line B-B of FIG. 13A.
[0149] FIG. 14 is a perspective view of the top half of the
receiver housing of the second embodiment portable compressor.
[0150] FIG. 14A is a bottom plan view of the top half of the
receiver housing of the second embodiment portable compressor.
[0151] FIG. 14B is a cross sectional view of the top half of the
receiver housing of the second embodiment portable compressor as
taken along line B-B of FIG. 14A.
[0152] FIG. 15 is an exploded perspective view of a ported piston
and an intake valve flap assembly of the second embodiment portable
compressor.
[0153] FIG. 15A is an exploded side view of the ported piston and
the intake valve flap assembly of the second embodiment portable
compressor with the ported piston partially cut away
[0154] FIG. 16 is an end elevational view of the ported piston of
the second embodiment portable compressor.
[0155] FIG. 17 is a side elevational view of the ported piston of
the second embodiment portable compressor.
[0156] FIG. 18 is a partially exploded perspective view of cylinder
liners, a drive system, and the intake valve flap assembly of the
second embodiment portable compressor.
[0157] FIG. 19 is a cross-sectional view of one of the cylinder
liners of the second embodiment portable compressor showing exhaust
valve ports thereof.
[0158] FIG. 20 is a side elevational view of a resilient band of an
exhaust valve of the second embodiment portable compressor for
cooperation with the exhaust valve ports thereof.
[0159] FIG. 20A is a cross-sectional view of the resilient band of
the exhaust valve of the second embodiment portable compressor as
taken along the line A-A of FIG. 20.
[0160] FIG. 21 is a perspective view of a third embodiment portable
compressor.
[0161] FIG. 22 is a side elevational view of the third embodiment
portable compressor.
[0162] FIG. 23 is an exploded perspective view of the third
embodiment portable compressor.
[0163] FIG. 24 is a perspective view of a manifold-defining base of
the third embodiment portable compressor.
[0164] FIG. 24A is a bottom plan view of the base of the third
embodiment portable compressor.
[0165] FIG. 24B is a cross-sectional view of the base of the third
embodiment portable compressor.
[0166] FIG. 25 is a perspective view of a gear and cylinder mount
of the third embodiment portable compressor.
[0167] FIG. 26 is a perspective view of a motor mount of the third
embodiment portable compressor.
[0168] FIG. 27 is a perspective view of an alternate embodiment
connecting rod and piston structure for use in a compressor having
cylinders spaced about a drive axis and extending radial
thereto.
[0169] FIG. 28 is a partially cross-sectioned view of an alternate
embodiment ported piston and intake valve.
[0170] FIG. 29 is a perspective view of a portable compressor
assembly and a detachable battery charger for use therewith.
[0171] FIG. 30 is a side elevational view of the portable
compressor assembly and the detachable battery charger with a
detachable battery pack removed.
[0172] FIG. 30A is an exploded end elevational view of the
detachable battery pack and a control box of the portable
compressor assembly.
[0173] FIG. 30B is an overhead plan view of the detachable battery
pack of the portable compressor assembly.
[0174] FIG. 30C is an end elevational view of the portable
compressor assembly without the detachable battery pack thereof
installed.
[0175] FIG. 31 is an opposite end elevational view of the portable
compressor assembly.
[0176] FIG. 31A is a partial close up side elevational view of a
compressor and carrying handle of the portable compressor
assembly.
[0177] FIG. 32 is a perspective view of an alternate embodiment
portable compressor assembly.
[0178] FIGS. 33A, 33B and 33C are perspective views of cut and
partially stripped sections of three embodiments of a hose adapted
for use in a portable tool system capable of powering pneumatic
tools and electric tools.
[0179] FIGS. 34A and 34B are perspective views of matable male and
female connectors respectively, for use in the portable tool
system.
[0180] FIG. 35 is a side elevational, partially cross sectioned
view of the male and female connectors for use in the portable tool
system when mated together.
[0181] FIG. 35A is a close up side elevational view showing
mounting of a bearing ball in the female connector for use in the
portable tool system.
[0182] FIG. 36 is a side elevational view of a socket body of the
female connector for use in the portable tool system.
[0183] FIG. 37 is a schematic illustration of the portable tool
system capable of powering pneumatic tools and electric tools.
[0184] In the drawings like characters of reference indicate
corresponding parts in the different figures.
DETAILED DESCRIPTION
Original Compressor
[0185] FIG. 1 shows an openable side of a first embodiment portable
reciprocating compressor 10 of the present invention, which
features a housing 12 comprising a removable cover 14 fastened in a
sealing manner to an end of an annular cylindrical exterior wall
16. FIG. 2 shows a driving side of the first embodiment compressor
10 opposite the opening side. Here a circular cover 18 closes off
the interior of the compressor housing 12 by sitting concentrically
within the space surrounded by the annular cylindrical exterior
wall 16 on a shoulder defined thereby to mate with an interior
surface of the annular exterior wall 16 and sit flush with an end
face 20 thereof. A driving end 22 of a crankshaft 24 extends
axially from within the cylindrical housing 12 through the second
cover 18 for connection to a suitable drive source, such as a
portable electric motor 26 as shown in FIG. 3. As seen in FIG. 4
and suggested by the cylindrical housing, the first embodiment
reciprocating compressor is of the radial type with a plurality of
gas compressors 28 spaced about the crankshaft 24, each extending
in a radial direction relative to a central axis of the housing 12
about which the annular exterior wall 16 extends. The portability
of the compressor 10 is established at least in part, by the fact
that the housing 10 acts not only to support the gas compressors
28, but also to define a receiving compartment for containing gas
compressed by the gas compressors. In forming the receiving
compartment, the housing may be considered to be a manifold, as it
collects compressed air in its hollow interior from each gas
compressor for discharge through a single outlet during use of the
portable compressor.
[0186] The housing 12 features an interior annular cylindrical wall
30 disposed concentrically within the exterior wall 16. Annular
spacing between the two walls forms a receiving compartment in
which the gas compressors 28 are disposed, extending radially
between the two annular walls. In the first embodiment, the
plurality of gas compressors includes six compressors arranged in
diametrically opposed pairs and evenly spaced about the central
axis of the housing 12. The space within the interior wall 30
defines a crankshaft compartment for housing components of the
compressor's drive system. The interior wall 30 features round
through-holes 32 each of which receives a drive end 34 of a
cylinder liner 36 of a respective gas compressor 28, A valve end 38
of the cylinder liner 36 opposite the drive end 34 is received in a
through-hole 40 provided in the exterior wall 16 axially aligned
with the respective though-hole 32 in the interior wall 30.
[0187] FIG. 5 shows one of the gas compressors 28 in an exploded
state. As with conventional reciprocating compressors, each gas
compressor 28 features a piston 42 disposed within and sealed to
the cylinder liner 36 for movement therealong to compress gas
contained therein. A connecting rod 44 features a piston end 46
having a through-hole provided therein to cooperate with a pin
extending diametrically through the piston 42 to provide a pivotal
connection between the piston and connecting rod 44 for pivotal
motion within a plane parallel to the housing covers 14, 18.
Connecting rod and piston connections of this type are well known
to those of skill in the art. A driving end of the connecting rod
44 opposite the piston end 46 is adapted for pivotal motion within
the same plane and connection to the crankshaft in a manner
described herein further below. A cylinder head 48 is adapted for
mounting by fasteners 49 on a flattened portion 50 of the exterior
surface of the exterior annular cylindrical wall 16. The cylinder
head 48 acts to hold the cylinder liner 36 in place within the
opening 40 of the exterior wall 16 by blocking motion radially
outward therefrom. The cylinder head 48 also provides an intake
valve for controlling feeding of air from outside the housing 12
into the cylinder liner 36 for compression by the piston 42. This
structure and workings of this valve are described herein further
below.
[0188] O-rings (not shown) are disposed radially between the
openings in the housing walls and the respective ends of the
cylinder liner 36 to provide seals to ensure that gas contained
within the receiving compartment defined between the housing walls
16, 30 will not leak into the crankshaft compartment within the
interior wall 30 or to the exterior environment surrounding the
housing 12. Such rings are commercially available and well-known to
those of skill in the art.
[0189] FIGS. 5 and 9 show master connecting rod 52 having a body
portion 54 from which an integral rod or shaft portion 57 extends
radially therefrom to a piston end 46 having the same structure as
the pistons ends of the connecting rods 44 for connection to a
respective piston. The body portion 54 of the master connecting rod
52 provides attachment points for the other connecting rods 44 so
that connection of the master connecting rod 52 to the crankshaft
24 will thereby connect all of the connecting rods 44 to the
crankshaft for actuation of the pistons 42. A driving end 56 of
each connecting rod 44 acts as a key for receipt in a respective
key-way of the body 54. The keys and key-ways are provided with
smooth rounded surfaces to allow pivoting of the connecting rod 44
with respect to an axis of the keyway. As shown in FIG. 9, the body
portion 54 is provided with five key-ways in the form of
cylindrical bores 58 overlapping with a periphery 60 of the
otherwise cylindrical body portion 54. The result is a series of
arcuate recesses into a peripheral wall of the body portion 54,
each of which extends more than 180 degrees such that a linear
distance between tips 62 of the recess is less than the diameter of
the bore. The driving end 56 of each connecting rod is cylindrical
and round and can be lifted or lowered into a respective recess and
fit so as to be pivotal therein, but is too large to be pulled from
the recess or key-way through the mouth defined by the opening
between the tips 62. The key-ways extend parallel to a central axis
of the body 54 along which a central bore 63 extends through the
body 54 perpendicular to the parallel top and bottom faces thereof.
With the rounded end 56 of each connecting rod received in the
rounded keyway 58 open between the tips 62 thereof, the connecting
rod can pivot about its rounded end 56 within a plane normal to the
central axis of the body 54 and the central bore 63 therein, the
pivoting being limited in either direction by contact of the stem
of the connecting rod between its ends with a respective one of the
tips 62. With the opening between the tips 62 being of lesser
diameter than the arcuate recess 58 and the connecting rod end 56,
withdrawal of the connecting rod from the recess or key-way along
the plane in which the connecting rod 44 is pivotal is prevented.
Withdrawal from the keyway is only allowed by linear movement of
the connecting rod parallel to the central axis of the body 54.
[0190] This master connecting rod 52 provides the necessary pivotal
connection to each connecting rod 44 in a relatively small space
without the use of small pins (such as in an arrangement similar to
that used to connect the rods and pistons) which may not provide
adequate strength at the mounting points to avoid breakage and
resulting detachment of the connecting rods. The connection point
of each connecting rod is housed between portions of solid material
of significant width or thickness, minimizing the chance of
failure. This master connecting rod is of a construction that
provides simplicity by avoiding use of pins, bushings and/or
bearings for connection to the connecting rods while being robust
yet small. The mating surfaces between the connecting rods 44 and
the master connecting rod 52 should be smooth and hard to prevent
vibration and wear. Known material treatment methods, such as
hardening and peen treating, may be used to attain suitable
characteristics at these connections. It is envisioned that a
connection structure similar to that between the master connecting
rod 52 and the connecting rods 44 may be adopted at the connection
between the connecting rods 44 and pistons 42 by overlapping a
cylindrical bore with the face of the piston nearest the master
connecting rod to form an arcuate keyway extending across the
piston into which the round cylindrical piston end 46 of the
connecting rod can be slid before mounting the piston within the
cylinder liner.
[0191] The master connecting rod 52 is journaled on a crank pin 64
which extends through the central bore 63 passed the master
connecting rod 52 on either side thereof for rigid connection to a
respective crank cheek 66 from which extends a respective portion
of the crankshaft journal 67. The crank cheek 66 features a
receiving hole 68 for receiving the end of the crank pin 64
extending beyond the master connecting rod 52. Relative rotation
between the crank cheek 66 and crank pin 64 may, for example, be
prevented by a set screw 70 as shown in FIG. 6 or by forming the
cooperating crank pin 64 and receiving hole 68 to have the same
straight-sided shape and size as shown in FIG. 5. The crankshaft 24
is thus formed by the crankshaft journal 67 defining the axis of
rotation and extending out of the compressor housing 12 through
each cover thereof, the crank pin 64 offset from, or eccentric to,
the crankshaft journal 67 and axis of rotation, and the two crank
cheeks 66 connecting the opposite ends of the crank pin 64 to the
crankshaft journal 67.
[0192] With a motor 26 operatively connected to the drive end 22 of
the crankshaft 24 extending from the compressor housing 12 as shown
in FIG. 3, rotation of the crankshaft 24 causes the master
connecting rod 52 to revolve around the crankshaft's axis of
rotation due to the connection of the master connecting rod to the
crank pin 64. The movement of the master connecting rod 52 along
this circular path within the crankshaft compartment transfers
rotational motion of the crankshaft 24 into linear displacement of
the pistons 42 within the cylinder liners 26 by means of the
connecting rods 44. As the master connecting rod 52 approaches a
particular gas compressor 28 during its revolution about the
crankshaft's axis of rotation, the piston 42 of that gas compressor
28 moves radially outward toward the external wall 16 of the
housing 12 to a maximum displacement. As the master connecting rod
52 continues moving and thus eventually passes the gas compressor
28, the piston is pulled back radially inward toward the interior
wall 30 of the housing 12. These outward and inward displacements
of the piston 42 correspond to the compression and intake strokes
of the compressor respectively.
[0193] As mentioned herein above, the housing 12 defines a
receiving compartment between the interior and exterior walls 30,
16 thereby contributing to the compressor's compactness and
portability by doubling as both a housing, support or base for
carrying the cylinders and a manifold for collecting compressed gas
from all the cylinders within a single enclosure. The gas
compressors 28 feature unique exhaust valves to take advantage of
this arrangement. In a conventional compressor, the gas compressors
are supported on their own frame or housing and compressed gas is
guided from the cylinders of the gas compressors to a receiving
tank outside the housing through an exhaust valve in each cylinder
head and a manifold connecting the exhaust valves and the tank. In
the first embodiment of the present invention, the external tank is
eliminated and the compressed gas from the cylinder liners 36 is
exhausted directly into the receiving compartment of the housing 12
by the unique exhaust valve arrangement.
[0194] Rather than exhaust compressed gas in the conventional
manner through an exhaust valve in the cylinder head 48 only to
then have to redirect it back into the housing 12 to the receiving
compartment with some type of additional manifold or separate tubes
for the multiple cylinders, the exhaust valve of the first
embodiment is disposed on the cylinder liner 36 within the
receiving compartment. FIG. 7 shows a close-up view of a cylinder
liner 36 near the valve end 38 thereof. The cylinder liner 36
features a cylindrical portion 72 of constant outer diameter which
flares outward to an end portion 74 of greater diameter toward each
of the valve and driving ends 38, 34 of the cylinder. The end
portion 74 nearest the valve end 38 contains the unique exhaust
valve. Ports 76 of the exhaust valve extending radially through the
wall of the cylinder liner 36 in the end portion 74 and are spaced
circumferentially thereabout. Disposed circumferentially about the
end portion 74 to cover the exhaust ports 76 is a band 78 of liquid
silicone rubber (LSR). The LSR band 78 has a predetermined density,
elasticity and size such that it stretches to fit snuggly over the
cylinder liner 36 to seal off the exhaust ports 76 when the
compressor 10 is not being run and also during the intake stroke of
the gas compressor 28. The band 78 stretches radially outward from
the cylinder liner 36 when exposed to higher pressure from inside
the cylinder liner 36 through the exhaust ports 76 during the
compression stroke of the gas compressor 28 to uncover these ports
76 and allow the exit of compressed gas from within the cylinder
liner 36 into the receiving compartment of the housing. The band 78
then returns to its original position covering the exhaust ports 76
as the pressure inside the cylinder liner 36 decreases as a result
of the passage of the compressed gas into the receiving
compartment. The exhaust ports 76 and LSR band 78 thereby cooperate
to form an exhaust valve operated by a difference in pressure
between the cylinder liner interior and receiving compartment, the
band 78 expanding about the cylinder liner to an open position
during the compression stroke and then resiliently returning to a
closed position to provide a seal between the cylinder liner
interior and receiving compartment at all other times. It has been
found that the characteristics of LSR are such that it performs in
this application with ease and durability while withstanding the
heat that is typically associated with compression. However, it
should be appreciated that other resilient materials exhibiting
similar properties and behaviour may be used to form the band 78 of
the exhaust valve.
[0195] The stretchable, flexible bands have an advantage over
conventional metal reed valves in that they do not retain heat in
the same way due to the significantly different material
properties. These unique valves thus contribute to an improved
efficiency of the compressor, as less of the energy used to open
the valves is effectively lost through the creation of waste heat.
In other words, a greater fraction of the energy applied to the
valve actually contributes to its physical movement than in a
conventional reed valve arrangement, so that less energy from the
compressed air is wasted, i.e. less heat is produced, in the use of
the unique compressor valve of the present invention than in the
use of a conventional reed valve having the same opening
pressure.
[0196] The resilient, stretchable, flexible bands also have other
advantages over conventional reed valves in that they don't corrode
under exposure to moisture and don't experience the same bending
fatigue that may lead to the failure of a reed valve to seat
properly over the port opening or snapping off the reed. The use of
LSR or similar material can thus improve the lifespan of a
compressor and reduce the need or frequency of maintenance, repair
and overhaul. Not only does the unique compressor valve structure
reduce the waste heat produced, but liquid silicone rubber has a
relatively high thermal stability, meaning that its material
properties are relatively stable over the temperatures ranges
experienced during typical use and storage of the compressor.
[0197] In the first embodiment, two preventive measures are taken
to ensure that the exhaust valve band 78 is not displaced axially
along the cylinder liner 36 when it stretches about the liner
during the compression stroke to open the exhaust ports 76.
Firstly, an exterior surface of the wall of the cylinder liner 36
features a recess 80 extending circumferentially about the end
portion 74 nearest the valve end 38, effectively creating flanges
82 on either side of the recess 80. The exhaust ports 76 extending
through the wall of the cylinder liner 36 are spaced along this
recess and the band 78 is therefore positioned in the recess to
cover them. The flanges 82 act to retain the band 78 in the recess
80, with the depth of the recess 80 being such that the band does
not fully withdraw therefrom during exposure to the elevated
pressures experienced during the compression stroke of the piston.
Secondly, the opening 40 in the exterior wall 16 of the housing 12
in which the valve end 38 and respective end portion 74 of the
cylinder lining 36 are received is sized to have a diameter
slightly larger than the end portion 74 to create and annular space
between the cylinder liner 36 and exterior wall 16. The band 78 can
expand into this annular space during the compression stroke, but
is limited in this expansion by contact with the exterior wall 16
at the periphery of the opening 40. This prevents the band 78 from
expanding far enough to slip over flanges 82 of the end portion 74
and risk being displaced from its port-covering axial position
along the cylinder liner 36.
[0198] In the first embodiment, the same unique valve structure is
used to form the intake valve in the cylinder head 48. As shown in
FIGS. 8A-8C, the cylinder head 48 features a cover portion 84 in
the form of a flat plate for flush mounting against a respective
flattened portion 50 of the exterior surface of the exterior
housing wall 16. Fastener holes 86 are provided in corners of the
cover portion 84 for receiving fasteners 49 that threadingly engage
the exterior wall 16. An inlet 88 is recessed into the cover
portion 84 from an outer face 90 thereof then continues passed an
inner face 92 of the cover portion so as to form a cylindrical
portion 94 projecting into the cylinder liner when the cylinder
head 48 is mounted on the compressor housing 12. The external side
of the inlet 88, i.e. that side viewable from outside the
compressor housing with the cylinder head installed thereon, is
shaped similar to a jet engine intake, with a curved outer edge 88A
forming a trumpet like flare in a direction outward from the
housing 12, like that of a velocity stack, and an inlet cone or
conical center 88B surrounded by the flared surface, concentric
therewith and tapering to its tip in a direction outward from the
housing 12. The contoured inlet serves to accelerate the flow of
air therethrough to increase the volume of air feeding into the
cylinder. These surfaces of the inlet are polished to provide a
highly smooth finish. The cylindrical portion 94 extending
perpendicularly from the inner face 92 of the cover portion 84
features intake ports 96 extending radially through its wall and
spaced circumferentially thereabout, creating passageways between
the inlet 88 and the interior of the cylinder liner 36 when the
cylinder head 48 is mounted. A flange 98 extends radially outward
along the circumference of the cylindrical portion 94 at an end
thereof opposite the cover portion 84, thereby creating a groove
100 between the flange 98 and inner face 92 for retaining another
resilient band 78. The resilient band 78 acts similar to that of
the exhaust valve, except it acts to let uncompressed gas enter the
cylinder liner 36 for compression therein by the piston 42.
[0199] During the intake stroke where the piston 42 retracts
radially inward toward the interior wall 30 of the housing 12 under
the action of the respective connecting rod 44 toward a fully
retracted position nearest the crankshaft compartment and the drive
system components disposed therein, pressure is reduced within the
cylinder liner 36. Since the pressure outside the housing 12
exceeds this reduced pressure within the cylinder liner 36, it acts
to expand the band 78 about the cylindrical portion 94 of the
cylinder head 48, thereby uncovering the intake ports 96 and
allowing gas to flow from outside the compressor housing 12 into
the cylinder liner 36 for compression by the piston 42 during the
compression stroke. As gas enters the cylinder liner 36, the
pressure difference between the surrounding environment and the
cylinder liner interior reduces, causing the resilient band 78 to
elastically return from its expanded open position to its closed
position sealing of the intake ports 96. During the compression
stroke, as the piston moves toward a fully extended position
furthest from the crankshaft compartment, the build-up of pressure
within the cylinder liner 36 therefore acts not only to stretch the
band of the exhaust valve to open the exhaust ports but also to
keep the band of the intake valve sealed over the intake ports. In
other words, increased pressure within the cylinder liner of each
gas compressor encourages expansion of the exhaust band but opposes
expansion of the intake band. Again, the characteristics of the
bands are carefully chosen to provide the necessary function at the
desired pressure levels of the compressor.
[0200] As shown in FIGS. 4 and 5, gas passageways 102 are provided
extending from within the receiving compartment between the
interior and exterior walls 30, 16 of the housing 12 through the
circular cover 18 for communication with a number of components
supported on the housing exterior. As seen in FIG. 2, these
components may include male and female connection fittings 104, 105
for connection of discharge lines or air delivery hoses having male
or female connectors thereon, a pressure gauge 106 for monitoring
pressure within the receiving compartment or manifold and a
depressurization valve 108 for manually emptying the receiving
compartment of compressed gas. It should be appreciated that the
compressor of the present invention may be equipped with other
components used with conventional compressors. For example, a
pressure switch can be installed and wired between the battery and
motor in a known manner to activate and deactivate the motor in
response to the pressure measured within the receiving compartment
or manifold to activate when additional compressed air is needed
and deactivate when the pressure reaches a particular value. The
pressure switch may be adjustable to allow adjustment of this value
to control the discharge air pressure for a particular application.
The removable and circular covers 14, 18 may feature cooling fins
110 to help dissipate heat produced during compression. FIG. 3
shows the compressor coupled with a DC motor 26 at the driving end
22 of the crankshaft 24, the DC motor being powered by a
schematically illustrated battery pack 112, which may be
rechargeable. In the first embodiment, the motor 26 is angled at
approximately 30 degrees to reduce the height to which the motor
extends from the circular lid 18, therefore requiring a
transmission 114 to transfer power from the motor to the
crankshaft. It should be appreciated that the motor may be mounted
in alternative orientations. In the first embodiment, the
crankshaft extends outward from the housing through each cover so
that a drive source can be connected to one end and a second
compressor may be coupled to the other end for running of two or
more compressors by the one drive source. It should be appreciated
that the compressor would still be operable with only one end of
the crankshaft extending outward from the housing for coupling with
a drive source.
[0201] Driven by the motor 26, the crankshaft 24 drives the master
connecting rod 52 about the rotational axis of the crankshaft by
means of the crank pin 64. This rotational motion is transferred to
linear displacement of the pistons 42 within the cylinder liners 36
by means of the connecting rods 44 (including the rod portion
extending from the master connecting rod, or master connecting
rod). The result is that the gas compressors 28 begin their
respective compression strokes in a sequential fashion about the
rotational axis, exhausting compressed gas into the receiving
compartment one-after the other so as to effectively provide a
near-continuous supply of compressed gas for discharge from the
compressor 10. In the same sequential fashion, the intake strokes
of the gas compressors 28 begin one after the other in a sequential
fashion about the compressor, thereby effectively providing a
near-continuous intake of gas from outside the compressor housing
to prevent emptying of the receiving compartment. The compressor of
the first embodiment is of the single-stage variety such that the
air compressed within each cylinder liner is discharged directly to
the receiving compartment rather than to another cylinder liner for
further compression.
[0202] With the six radially arranged gas compressors spaced around
the driveshaft axis, when the piston of one gas compressor
completes its compression stroke by reaching the fully extended
position, the piston of a diametrically opposed gas compressor
completes the intake stroke with its piston reaching the fully
retracted position. At this moment, two of the four remaining gas
compressors are in their compression stroke with their pistons
moving toward their fully extended position, and the other two gas
compressors are in their intake strokes with their pistons moving
toward the fully retracted position. The even spacing of the gas
compressors about the driveshaft axis ensures that the timing
between the completion of one compression stroke and the next is
consistent at a constant rotational speed of the driveshaft.
[0203] As seen in FIG. 4 to 6, each of the crank cheeks 66 extends
passed the crankshaft journal 67 to form an integral counterweight
116 in the form a semi-circular lobe disposed diametrically
opposite the master connecting rod 52 about the crankshaft's
rotational axis. The counterweights help minimize vibration of the
compressor 10 caused by eccentric rotation and reciprocation during
operation. The counterweights may be provided with closable
containers 118 thereon for storing weight-adding material to
provide dynamic balancing by means of adding or removing such
material to adjust the overall weight of the counterweights. Access
to such containers is provided by means of the removable lid
14.
[0204] The compressor is not oil-lubed, but rather includes a ring
120 of Teflon.TM. or other suitable low-friction material extending
about the circumference of each piston 42 to decrease friction
between the cylinder liner 36 and piston. Piston rings are used in
a conventional manner to provide seals between the pistons and
cylinder liners to prevent leakage of air from the gas compressors
into the crankshaft compartment.
[0205] A working prototype of the first embodiment was produced and
coupled with a motor from a 28V cordless skill-saw, powered by a
28V lithium ion battery, by a custom made 1:1 drive-line and
housing. The combined components weigh 12 lbs or less, dependent on
materials used, and the prototype compressor is 7 inches in
diameter and 2.5 inches thick. With the motor attached its overall
dimensions fit within a volume of 4.times.7.times.14 inches. The
28-volt DC motor of the prototype develops 465-in/lb torque at 4200
rpm and the six pistons are 1-inch diameter with a 11/4 inch
stroke. The design flow rate of the first embodiment prototype
compressor is 7 CFM at 70 PSIG discharge. Another configuration has
the motor positioned directly on top of the compressor resulting in
a direct drive as opposed to the angled side line transmission.
[0206] The first embodiment compressor may be provided as part of a
compact system which can be easily carried by a user to power any
number of pneumatic tools without any limitation of movement causes
by power cords or air hoses. Such a system may include: [0207] Back
Pack--a lightweight carrying case, meant to be worn on the back of
the operator. The pack may have adjustable padded straps, carrying
handle, pockets for accessories, hookups and loops for carrying and
connecting tools, and inlet air and cooling air vents. [0208]
Chassis--a lightweight mounting mechanism to which the compressor
motor and instruments are mounted, and in turn the entire chassis
is placed into the backpack. [0209] Compressor Housing--the
compressor housing is an integral unit containing the crankcase
(crank shaft compartment), crankshaft, connecting rods, pistons,
cylinder liners, cylinder heads, and discharge air exhaust header
(circular cover having at least one passageway or port
therethrough, each equipped with connection fitting). The
compressor is a single stage, air-cooled radial design with
cylinders opposite each other in a balanced opposed configuration.
Two compressor frames may be bolted together back to back and
driven through a flexible coupling for applications which require
increased volumes of air [0210] Motor--the DC drive motor drives
the compressor directly or indirectly through gearbox(s) and is
mounted onto the chassis with vibration isolators. [0211] Battery
Pak--the DC battery(s) is placed into an adapter that is mounted on
the Chassis. The batteries are removable for external recharging.
[0212] Pressure Switch--an air/electrical pressure switch is
mounted on the chassis to control the discharge air pressure for
the application and is adjustable. [0213] Power Switch--an
electrical switch located externally on the backpack to isolate the
batteries from the motor, and accidental operation. With the power
switch on, the pressure switch activates the motor as needed to
maintain the discharge air pressure, [0214] Depressurization
Valve--a manual valve located externally on the backpack to
depressurize the compressor for maintenance or travel. [0215]
Pressure Gauge--a pressure indicator mounted on the discharge
header of the compressor to indicate actual working pressure, as
well as to calibrate the pressure switch [0216] Quick Disconnect--a
standard pneumatic tool quick disconnect mounted externally on the
backpack to connect to an air tool hose.
[0217] The efficiency of the first embodiment compressor is such
that ample amounts of compressed air are produced so quickly, that
there is no need for a separate volumetric vessel (tank). Enough
compressed air is produced on demand to operate most typical hand
held air activated tools. Since this compressor is so efficient, it
is therefore possible to drive it with a battery powered motor and
achieve the same out put as one would expect from a power corded
compressor. This being the case, it is therefore possible to
combine the battery, motor and compressor, place them together into
a wearable pack enabling an individual to freely roam while having
ample compressed air at their finger-tips to operate any air tool
which normally would only be driven by a stationary compressor via
a long hose.
P3 Compressor
[0218] FIGS. 10 to 12 show a second embodiment portable compressor
200 that is similar to the first embodiment portable compressor in
that it features six cylinder liners 36 in a radial arrangement and
a similar drive system featuring a motor 26 driving revolution of a
master connecting rod 52 through a crank to effect sequential
compression strokes of pistons 42 within the cylinder liners to
discharge compressed gas into a common receiver. The second
embodiment compressor 200 however is different from the first
embodiment compressor in a number of ways.
[0219] As shown in FIGS. 10 and 11 the second embodiment compressor
200 does not feature a unitary housing, but instead includes two
separate housings. A receiver housing 202 defines a manifold into
which compressed gas is exhausted from the cylinder liners 36 and
is formed by a bottom half 203 and a top half 204 which mate
together with the cylinder liners 36 disposed between them. With
its halves mated together, the receiver housing 202 is annular in
shape so as to define a central opening 206. A crank housing 208 is
positioned within the central opening 206 of the receiver housing
202 and similarly has an annular shape defining a central opening,
within which the body of the master connecting rod 52 and the crank
pin are disposed. The cylinder liners 36 are received in openings
210 extending radially through the annular crank housing 208 from
the central opening thereof toward the surrounding receiver housing
202. The cylinder liners 36 are sealed to the crank housing 208 at
these openings therein and project radially outward from the crank
housing 208 into the surrounding receiver housing 202.
[0220] Unlike those of the first embodiment, the cylinder liners 36
of the second embodiment compressor 200 do not flare outward to an
increased diameter at opposite ends of a cylindrical portion 72.
Instead, each cylinder liner 36 has a threaded portion 212
extending from the drive end 34 thereof nearest the central opening
of the crank housing 208 so as to sealingly mate with corresponding
threads provided on the respective opening 210 through the crank
housing 208. A shown in FIGS. 18 and 19, the cylinder liner 36 also
does not flare outward toward the valve end 38 opposite the drive
end 34, but does feature pair of flanges 82 disposed on opposite
sides of a recess 80 in its exterior surface. The one of these
flanges 82 furthest from the drive end 34 of the cylinder liner
defines the valve end 38 thereof, which in the second embodiment
compressor is closed. At the recess 80 defined between the flanges
82, a plurality of exhaust ports 76 spaced about the central
longitudinal axis of the cylinder extend radially through the
cylinder liner 36 to communicate its hollow interior or cylindrical
bore with its exterior. A resilient band of flexible material 78 is
stretched about the cylinder liner 36 within the circumferential
recess 80 to cooperate with the exhaust ports 76 in the same way as
in the first embodiment to define an exhaust valve.
[0221] In the second embodiment compressor 200, the recess 80 of
the exhaust valve has a tapered V-like shape narrowing inward from
the radially outermost extent of the flanges 82 toward the hollow
interior of the cylinder liner 36, as best shown in FIG. 19. As
shown in FIG. 20A, the flexible resilient band 78 also tapers from
a maximum width at its outermost surface 78a to a minimum width at
its innermost surface 78b. The groove 80 and the resilient flexible
band 78 taper at the same angle for an optimum fit and a tight seal
when the band is not being stretched radially outward under the
force of compressed air forced against it from the interior of the
cylinder liner 36 through the exhaust ports 76.
[0222] FIG. 10 shows the second embodiment compressor 200 without
the top half 204 of the receiver housing 202 thereof so as to
illustrate the mating side, or face, 214 of the bottom half 203 of
the receiver housing, which is shown in isolation in FIG. 13. A
series of fastener holes 216 extend into the bottom half 203 from
the mating face 214 and are spaced thereabout adjacent the bottom
half outer periphery 218. Spaced radially inward from the outer
periphery 218 and the fastener holes 216 thereadjacent is an outer
seal groove 220, extending fully about the central opening 206 of
the receiver housing 202, in which an o-ring like seal is disposed
to seal against a mating face of the top half 204 when the two
halves of the receiver housing are mated together.
[0223] Just radially inward from the outer seal 220 is a groove 222
recessed into the receiver housing bottom half 203 from the mating
face thereof, also extending fully around the central opening 206.
Unlike the round central opening 206 around which it extends, the
groove 222 has a longitudinal path extending around the central
opening 206 with the grooves outer edge 222a outlining a hexagonal
type shape defining rounded corners 222b and six straight segments
222c of the groove, each straight segment extending perpendicular
to the longitudinal axis of a respective one of the cylinder
liners. At the midpoints of these six linear segments 223 are
recessed portions 224 of the groove 222 dipping further downward
into the bottom half 203 from the mating face 214 thereof than the
rest of the groove 222. The groove 222 is of sufficient width at
each of these recessed portions 224 to receive between its sides
the two flanges 82 at the valve end 38 of each cylinder liner 36
forming the valve seat groove 80 that houses the resilient band of
the exhaust valve. The groove 222 is less wide between the recessed
portions 224 so that the flanges 82 will only seat properly within
the recessed portions 224. Each recessed portion 224 of the groove
222 is arcuate in a vertical plane along the groove's longitudinal
path around the central opening 206 so as to form a rounded cradle
or seat in which the round flanges 82 of the cylinder liner 36
projecting radially outward from the cylindrical portion 72 thereof
can rest. An inner portion 226 of the bottom half mating face 214
radially inward of the groove 222 at each of the recessed portions
224 thereof is similarly arcuately recessed, although at a smaller
diameter, in a vertical plane to seat or cradle the cylindrical
portion 72 of the respective cylinder liner 36 projecting from the
flanged valve end 38 thereof into the central opening 206 of the
receiver housing 202. One such seat or cradle for supporting the
cylindrical portion of a respective cylinder liner is shown at 227
in FIG. 13.
[0224] Just radially inward of the groove 222 and concentric with
the central opening 206, groove 222, outer seal groove 220 and
outer periphery 218 is an inner seal groove 228 extending fully
around the central opening 206 in the inner portion 226 of the
mating face 214. Between the cylinder liners 36, the inner seal
groove 228 is disposed radially outwardly relative to its position
at the arcuate recesses in the inner portion 226 of the mating face
214 at which the groove 228 dips downward beneath the cylinders to
form a seat or cradle 227. Spaced about the central opening 206 at
these more outwardly disposed portions 230 of the inner seal groove
228 is a second set of fastener holes 232 positioned between these
outward portions 230 and an inner periphery 234 of the bottom half
203 of the receiver housing and extending into the bottom half from
the inner portion 226 of the mating face 214 thereof.
[0225] FIG. 14 shows the top half 204 of the receiver housing 202
in isolation before assembly with the bottom half 203. With the
primary exception of the seal grooves, the top half 204 of the
receiver has substantially the same structure as the bottom half.
The top half 204 has a mating face 214' divided into inner and
outer portions 226' and 236' by a groove 222' extending
concentrically about the central opening 206 in a generally
hexagonal shape with rounded corners. The groove 222' has arcuately
recessed portions 224' centrally disposed along straight segments
of the groove disposed between the rounded corners thereof to align
with the recessed portions 224 of the bottom half 203. When the two
halves of the receiver housing 202 are brought face to face with
one another, the outer portions 236, 236' of the mating faces 214,
214' are sealed together by a poured in place seal disposed within
the outer seal groove 220 and the inner portions 226, 226' are
sealed together between the cylinder liners 26 at the outwardly
disposed portions 230 of the inner seal groove 228 by a poured in
place seal disposed therein. The seal disposed in the inner seal
groove 228 of the bottom half 203 of the receiver housing 202 also
acts to seal the bottom half 203 to each of the cylinder liners 36
by engagement of the seal along each of the cradles or seats 227
with the bottom half of the cylindrical portion 72 of a respective
cylinder liner 36.
[0226] As sealing between the two halves of the receiver housing
and between the bottom half 203 and the cylinder liners 36 is
provided at the seal grooves of the bottom half 203, the top half
204 only needs to provide for sealing between itself and the
cylinder liners 36. Six cylinder seal grooves 238 are provided on
the top half 204 of the receiver housing 202 each extending along a
respective one of the cradles 227' formed by a vertically disposed
arcuate recess in the inner portion 226' of the mating face 214'.
Each cylinder seal groove 238 extends at each of its ends slightly
passed the edge 240 defined between the arcuate seat or cradle 227'
and the neighbouring flat segment of the inner portion 226' of the
mating face 214' to ensure that when the halves are assembled
together with the cylinder liners 36 between them, no gaps exists
between the receiver housing 202 and the cylinders at the cylinder
seats or cradles 217, 217'. A poured in place seal is provided at
each of the cylinder seal grooves 238.
[0227] For assembly of the second embodiment compressor 200, the
piston liners 36 are threaded into engagement with the threaded
openings provided in the outer periphery of the crank housing 208
as shown in FIG. 10. The pistons are mounted within the cylinder
liners with their respective connecting rods attached and the slave
connecting rods 44 are connected to the master connecting rod 52.
Slave connecting rods are those that are not integral with the body
of the 54 of the master connecting rod, but instead are pivotally
connected thereto as disclosed for the first embodiment compressor,
and the stem or shaft 57 integral with the body 54 being part of
the single remaining connecting rod. A round disc-like cover 242
having an outer diameter approximately equal to that of the body 54
of the master connecting rod 52 is disposed thereatop and held in
place by the head of the crank pin 64 extending downward
therethrough on which the master connecting rod 52 is journaled.
Beneath the master connecting rod body 54, the crank pin passing
therethrough is secured to the crank cheek 66 and integral
counterweight 116 which in turn has its crank journal 67 coupled to
the driveshaft of the motor 26, which in the second embodiment is a
disc-shaped pancake or torque motor fixed to the bottom of the
crank housing 208 to help minimize the dimensions of the compressor
200.
[0228] With the crank housing 208, the gas compressors and the
drive system assembled, the crank housing 208 and attached motor 26
are lowered into the central opening 206 to seat the cylindrical
portions 72 of the cylinder liners 36 within the cradles 227
defined by the arcuate recesses in inner portion 226 of the mating
surface 214 and seat the flanges 82 of the cylinder liners 36
within the recessed portions 224 of the groove 222. This partial
assembly is illustrated best by FIG. 10, in which the top half 204
of the receiver housing has yet to be installed. To complete the
assembly, the top half 204 is lowered onto the bottom half 203,
with the generally hexagonal shape of the outer periphery walls
218, 218' of the two halves 203, 204 allowing easy visual alignment
thereof to dispose the cylinder cradles 227, 227' of the opposing
halves in alignment above and below the cylinder liners 36. The
fastener holes 216', 232' of the top half 204 of the receiver
housing 202 are through holes while the fastener holes 216, 232 of
the bottom half 203 are threaded blind holes. The top half fastener
holes 216', 232' align with the bottom half fastener holes 216, 232
so that threaded fasteners 244 can be passed into the bottom half
203 and secured thereto to clamp the two halves of the receiver
housing together with the cylinder liners 36 between them.
[0229] As shown in FIGS. 11A and 11B, with the two halves 203, 204
of the receiver housing 202 having generally the same structure,
the grooves 222, 222' of the two halves are mirrored across the
mating faces of the halves to form an enclosed channel 246
extending fully around the central opening 206 with the valve end
38 of each cylinder liner 36 disposed therein. The seal disposed in
the outer seal groove 220 of the bottom half 203 provides an air
tight seal between the outer portions 236, 236' of the mating faces
214, 214' around the entire channel 246 along the outer side
thereof. The seal disposed in the inner seal groove 228 of the
bottom half 203 seals between the two halves along the outwardly
disposed portions 230 of the inner seal groove between the cylinder
liners 36 as well as between the bottom half and each cylinder
liner 36 along the arcuate recesses in the inner portion 226 of the
mating surface forming the cylinder cradles 227. The seal disposed
in the cylinder seal grooves 238 of the top half 204 complete the
sealing off of the channel 246 by providing an air tight seal
between the top half 204 and each of the cylinder liners 36.
[0230] The channel 246 thus forms a receiver, or collector or
manifold, that extends about each and all of the cylinder liners 36
to sealingly enclose the valve ends 38 thereof which include the
exhaust valves formed at each cylinder by the exhaust ports 76
extending radially through the cylinder liner 36 between the
flanges 82 thereof and the resilient band 78 extending about the
cylinder liner 36 between the flanges 82. At three of the rounded
corners 222b of the groove 222 in the bottom half 203, gas
passageways 102 are provided extending through the bottom half 203
parallel to the axis about which the annular receiver housing 102
extends. The bores defining these passageways pass through an
exterior face 248 of the bottom half 203 opposite the mating
surface 214 thereof. Just as in the first embodiment compressor,
these passageways are threaded to provide sealed coupling with
connection fittings, a pressure gauge, a depressurization valve or
a pressure switch.
[0231] Compared to the first embodiment compressor, the receiver
housing 102 provides a significantly smaller manifold or receiver
for collecting compressed air from each of the cylinders for
discharge through a common outlet, such as a male or female
connection fitting coupled to a respective one of the gas
passageways 102 for connection to an air delivery hose adapted for
connection to a pneumatic tool. By defining a channel of relatively
small cross section enclosing the exhaust valve on each cylinder
liner, but not much else of the cylinder liner, the volume of space
for receiving compressed gas is reduced. Keeping the volume of the
receiver to a minimum is desirable, as it results more of an
air-on-demand situation where the compressor is run more in
response to an actual need or demand for compressed air and less
for the purpose of filling up a reservoir of compressed air. Having
the six cylinders arranged spaced about the driveshaft axis in a
radial arrangement such that the pistons sequentially reach their
maximum displacement to complete their compression strokes one
after the other around the compressor in quick succession provides
enough compressed air to run conventional pneumatic tools
continuously without an external air tank and with minimal
pulsing.
[0232] As shown in FIGS. 15 to 18, the second embodiment compressor
200 features a different intake arrangement than the first
embodiment compressor. Rather than having intake valves provided in
cylinder heads mounted sealed to the valve ends of the cylinder
liners, the second embodiment features intake valves formed on the
pistons 42. Two intake ports 250 extend axially through the piston
42 on opposite sides of a central span 252 extending diametrically
across the round cylindrical annular wall 253 defining the
periphery of the piston 42. Each intake port is of a somewhat
semi-circular cross sectional shape with a diameter slightly less
than that of the piston so as to take up a significant portion of
the piston's cross sectional area while leaving the central span
intact between the two ports. A face 254 of the piston opposite the
end thereof from which the connecting rod 44 projects for
connection to the master connecting rod 52, defined by the
respective ends of the annular wall 253 and central span 252,
surrounds each of the intake ports 250. An o-ring groove 256 in the
face 254 of the piston 42 extends around both of the intake ports
250 to receive a conventional o-ring to provide proper sealing of
the intake ports 250 when closed. A flap of flexible resilient
material, such as LSR, 258 is shaped to define a circular disc 260
having three cylindrical projections 262 of equal length spaced
along a linear strip 263 formed on a face of the disc and extending
diametrically thereacross to project from the strip in a
perpendicularly away from the disc face. On opposite sides of the
linear strip 263, two thin metal plates 264 are bonded to the face
of the flap disc 260 on which the strip is formed. Each plate 264
is shaped liked the respective portion of the flap disc 260 to
which it is bonded, such that the arcuate edge of the plate is
substantially flush with the periphery of the flap disc 260. The
projections 262 are of sufficient length to project from the strip
263 to engage with three corresponding blind holes 266 extending
into the central span 252 of the piston 42 from the face 254
thereof at positions spaced along the diametrical span 252 with the
same center to center spacing as the projections.
[0233] The linear strip 263 and the diametrically extending portion
of the disc 260 of the flexible flap 258 along which the strip 263
extends define a fixed portion 268 of the flap 258 retained in a
generally fixed position relative to the piston face 254 by
engagement of the projections 262 and blind holes 266. The
remainder of the disc 260 on each side of this fixed portion
defines a movable portion 270 of the disc 260 extending laterally
therefrom and is movable relative to the fixed portion in a
pivotal-like motion resulting from bending of the flexible disc 260
along the boundary between the fixed and movable portions, in other
words along the edge 272 between the linear strip 263 and the disc
face on which the strip is formed. With the projections 262
received in the blind holes 266, the movable portions 270 are
movable relative to the fixed portion 268 from a closed position in
which they are coplanar, in other words where together with the
fixed portion 268 they form the flat disc 260, to an open position
in which they each extend out of the plane of the fixed portion 263
away from the piston face 254. In the closed portion, the plate 264
fixed to each movable portion 270 of the disc rests flush against
the o-ring seal 256a disposed in the o-ring seal groove 256 along
the arcuate portion of the respective somewhat semicircular port
250 for covering or closing thereof. In the open position, the
plate 264 is at least partially lifted from this flush contact with
the seal 256a to open or uncover the port to allow airflow
therethrough.
[0234] As best shown in FIG. 15a, the linear strip 263 is stepped
at each end from a central portion 263a, from which the projections
262 extend, to a shorter end portion 263b of smaller thickness
equal to that of each metal plate 264. With the flap in place for
use, the central portion 263a will sit flush against the face of
the central span 252 of the piston over its full length from the
inside perimeter of the annular o-ring seal groove 256 at one end
of the central span 252 to a diametrically opposite point on the
inside perimeter of the o-ring seal groove 256. The difference in
thickness between the central portion 263a of the strip 263 and the
end portion 263b is equal to the distance by which the o-ring seal
256a received in the o-ring seal groove 256 projects from the
piston face 254 in a direction perpendicular thereto. Like the
metal plates 264 do when the flap is closed over the ports, the end
portions 263b of the strip thus rest flush with the face of the
o-ring seal 256a projected slightly past the piston face 254 from
the o-ring seal groove 256 therein. Spanning the full length of the
central span 252, the ends of the central portion 263a of the strip
263 abut against inner periphery of the o-ring seal 256a. The
stepped ends of the strip thus 263 seal up and over the o-ring seal
256a from within the annular o-ring seal groove 256 between the two
plates to complete the annular seal around the piston face when the
movable portions of the flap are in the closed position to seal of
both ports 250. In the open position, these stepped ends of the
strip 263 remain engaged to the o-ring seal due to the fixed
engagement between the integral projections 262 with the piston,
but the metal plates 264 are lifted from off the o-ring to allow
air to pass through the intake ports.
[0235] In the illustrated embodiment, the disc 260, the strip 263
and the projections 262 are an integral unit that may be possible
to mold into place on the piston. For example, two temporary
elongate linear barriers may be placeable along the central span
252 of the piston on the opposite sides thereof each being equal in
height to an o-ring seal 256a disposed in the o-ring seal groove
256, to form parallel chords of the circle defined by the o-ring
seal. Each metal plate 264 can then be set atop the barrier and
arcuate portion of the o-ring seal on the respective side of the
central span. With the o-ring equipped piston and the plates so
arranged within a mold, LSR can then be poured or injected into the
mold over the piston and the plates sitting thereatop. The LSR
entering the area between the barriers along the central span 252
forms the strip 263, the barriers preventing the LSR from flowing
therepast beneath the plates and into the ports. LSR flowing from
this area between the barriers down further into the blind holes
266 in the central span 525 forms the projections, the holes each
being threaded so that when the LSR dries, interference between the
periphery of each projection with the threads of the respective
hole 266 prevent linear withdrawal to secure the flap to the
piston. In other words, the threads within each hole or bore 266
act as barbs projecting into the periphery of the respective
projection 262 of the flap. Rotation of a projection to withdraw
from the respective threaded hole or bore is prevented by the use
of multiple projection and threaded hole pairings. A thin layer
formed over the strip once the area between the barriers is filled
defines the disc 260. Forming separate seal grooves around the two
ports, rather than the single o-ring seal groove 256 extending
about both ports, may improve the ease of molding the flap onto the
piston by preventing leakage of LSR into the ports without the need
for some temporary measure for this purpose during molding.
[0236] Alternatively, the flap 258 may be formed and mounted on the
piston in a two-stage molding process in which the disc 260 and the
strip 263 are formed on the two metal plates 264 held positioned
relative to one another in a mold as though in their in-use closed
position (co-planar with their straight sides spaced from one
another by a distance corresponding to the strip 263 to be formed),
the mold shaped such that LSR flowed between the plates will form
the strip 263 and LSR flowed onto the faces of the plates will form
the disc thereatop integral with the strip. The mold would feature
three projections spaced along the strip-forming portion therein to
produce three through holes spaced along the strip and passing
through the strip and the disc integral therewith. Having so formed
the disc and strip on the metal plates, the second stage involves
fixing these components in place on the piston so that the three
holes in the disc and strip structure align with the blind holes
266 in the central portion 252 of the piston and the metal plates
264 sitting flush on the o-ring seal already installed on the
piston. LSR is then poured or injected into the blind holes 266 in
the piston through the corresponding holes in the strip and disc
formed during the first stage, this LSR drying to form the same
connection with the piston as described above and also bonding to
the previously formed LSR disc and strip.
[0237] Rather than using the projections 262 to secure the flap to
the piston, threaded fasteners may be passed through the disc 260
to engage the threaded holes in the piston. A metal strip of
material may be applied on a side of the disc opposite the piston
for passage of the fasteners through the metal strip and the
flexible flap to better distribute pressure applied to the disc by
the fastener heads along the fixed portion to help keep it
stationary.
[0238] With the intake valves formed on the pistons 42, air is not
drawn into the cylinder liners 36 through cylinder heads disposed
on the outer periphery of the compressor like the first embodiment,
but instead is drawn into the cylinder liners 36 through a hollow
space encircled by the annular crank housing 208. As this hollow
space or crank chamber at the center of the annular crank housing
208 is closed at the bottom by the motor 26, a top end of this
space must be left at least partially open to allow intake air to
feed into the cylinder liners 36 through the openings 210 in the
annular crank housing walls. Therefore a lid 274 engagable to the
crank housing 208 proximate the top face 276 thereof has openings
278 therethrough to allow airflow into the hollow space, or crank
chamber, defined by the annular crank housing 208 containing
components of the drive system. The lid is disc shaped having four
tabs 280 projecting radially outward therefrom at evenly spaced
points about its circumference. Four corresponding notches 282
extend radially into the inner periphery of the crank housing 208,
each having a respective slot extending from a side thereof below
and parallel to the top face 276 such that upon lowering of the lid
slightly into the crank chamber to rest the tabs 280 come within
the notches 282 open at the top surface 276, the lid 274 can be
rotated about its axis to slide and snap the tabs 280 into the
slots. This prevents linear withdrawal of the lid 274 upward from
the crank housing 208 without a manual unlocking rotation of the
lid to return the tabs 280 to the notches 282 open at the top
surface of the 276 of the crank housing 208.
[0239] When the pressure inside the cylinder liner 36 between the
piston 42 and the valve end 38 of the cylinder liner decreases
during the intake stroke of the piston 42 back toward the crank
housing 208, the air pressure outside the compressor 200 eventually
exceeds it. As the intake ports 50 are in fluid communication with
the outside air surrounding the compressor 200 through the cylinder
liner 36, opening 210, crank chamber and the crank chamber inlet
defined by the openings 278 in the lid 274, this increase in
pressure forces the movable portions 270 of the flexible flap and
the metal plates 264 bonded thereto into the open position to
uncover the intake ports 250 and allow airflow into the cylinder
liner 36 between the valve end 38 thereof and the piston 42 for
later compression by the piston 42 during the compression stroke.
As air passes into the end of cylinder liner 36 through the intake
ports 250, the pressure difference between the surrounding
environment and the cylinder liner interior reduces, causing the
movable portions 270 of the resilient flap to elastically return
from the bent open position to the closed position, coplanar with
the fixed portion 268, to seal off the intake ports 50.
[0240] The relatively large total cross sectional are of intake
ports 50 of the second embodiment compressor compared to those of
the first embodiment increase the intake air volume. At the
relatively low pressures associated with the use of typical
pneumatic tools, the large ports and LSR flap should allow
significant volumes of compressed air to be produced relatively
quickly from the plurality of cylinders, with relatively little
heat retention, to build up sufficient pressure for powering rapid
repetitive actuation of the pneumatic tool. It is also thought that
these unique valves may be able to overcome the limitations on the
port size of conventional reed valves relative to the achievable
compression, and may therefore have potential for use in higher
pressure applications. The use of a flexible resilient flap having
a movable portion extending from a fixed portion to carry a
separate metal plate attached thereto for covering a respective
port reduces the likelihood of premature failure compared to metal
or fiberglass reed valves which may fatigue and fail to seat
properly or snap off, as all of the flexing or bending is handled
by the LSR or other suitable flexible material, and not by the
metal plates. The metal plates, by having significantly more
rigidity than the flexible flap, each provide a consistently flat
surface for sealing with the o-ring and limit the flexing or
bending of the flap to the border between the fixed and movable
portions to allow only the desired pivotal-like motion thereabout.
Like the flexible, resilient LSR bands of exhaust valves of the
second embodiment and both valve sets of the first embodiment, the
LSR flap of the second embodiment intake valves reduce waste energy
compared to heat-retaining conventional reed valves and offer
improved resistance to stress-induced failure.
[0241] It should be appreciated that a flap with a fixed portion
secured to the surface surrounding a single port on one side
thereof and only a single corresponding movable portion would work
in the same way, and that a valve of this type is not limited to
specific use as an intake valve nor is it limited to a
piston-mounted valve type. It should also be appreciated that
flexible material other than LSR may be used to provide similar
advantages and that the plates may be made of materials other than
metal while still providing the greater rigidity required at the
movable portion of the valve flap. In the second embodiment
compressor, the central span 252 spans the full interior diameter
of the annular piston wall 253 only partially along the piston's
length from the face 254, as shown in FIG. 17, so as to provide
room for pinning of the connecting rod 44 inside the annular 253. A
seal ring groove 290 and a rider band groove 292 are provided in
the exterior surface of the annular piston wall 253, extending
circumferentially thereabout and spaced along piston's length, to
support a seal ring and a rider band, such as a friction reducing
Teflon piston ring, proximate the face 254 nearest the valve end 38
of the cylinder liner 36 and the opposite connecting rod end 294 of
the piston respectively.
[0242] Like the first embodiment compressor, the second embodiment
compressor 200 may be mounted within a backpack for carrying on the
back of a user along with a rechargeable battery pack. It should be
appreciated that the compressor 200 may be adapted to have the
battery pack releasably mounted directly thereto, with wiring of
the electrical supply, motor and a pressure switch being well known
to those of skill in the art. With the compressor, including the
motor, and battery pack provided in such a compact unit, especially
with the use of a relatively thin and flat pancake or torque motor,
a full size pack may not be necessary to easy carrying by a user.
For example, the compressor may be equipped with a tightenable
strap for wearing about the waist or leg of a user. When carried
within a bag or other somewhat closed container, the use of mesh or
otherwise perforated material will reduce any interruption of a
steady supply of intake air to the compressor. The battery pack may
be connected to the compressor through openings in such a meshed
sack or container through the openings therein, to allow easy and
quick replacement of a rechargeable battery without having to first
remove the entire assembly from its carrying container.
FP Minus 1
[0243] FIGS. 21 to 23 show a third embodiment portable compressor
300, that like the compressors of the first two embodiments
features a plurality of reciprocating type gas compressors arranged
radially about a central axis in a common plane perpendicular
thereto and carried by a receiver or manifold that receives
compressed air from each gas compressor cylinder for discharge
through a common outlet. The third embodiment compressor differs
significantly in structure and in that is has only three cylinders.
However, those of skill in the art will appreciate that the number
of cylinders present in each embodiment may be varied.
[0244] A base 302 of the third embodiment compressor 300 supports
three gas compressors 28 equally spaced about and extending
radially relative to a central axis of the base 302. The base 302
is a block of solid material having two identical, flat, parallel
opposing faces 304, 306 with a periphery defining a constant
thickness of the body 302 perpendicular to the opposing faces 304,
306 that is significantly less than the span of the identical faces
304, 306. The periphery of the body 302 is shaped such that the
body has the appearance of having been formed from an irregular
hexagonal body with three long sides of identical length and three
shorter sides of identical length, the short and long sides
alternating along the periphery of the hexagonal body, which has
had the long sides each equally recessed toward the center of the
body along the opposed faces 304, 306. Looking at the plan view of
FIG. 24A, each resulting recessed longer side 308 of the body 302
is made up of three linear segments, a longest central segment 308a
and two shorter end segments 308b at opposite ends of the central
segment. The central segment 308a of each longer side 308 is
parallel to an imaginary line extending between the adjacent ends
310a of the two shorter sides 310 neighbouring the longer side 308.
The end segments 308b of the same longer side 308 extend obliquely
outward from the central segment 308a to connect with the ends 310a
of the same neighbouring shorter sides 310 at right angles
thereto.
[0245] As shown in FIGS. 21 and 22, each of the cylinder liners 36
is mounted to the top face 304 of the body 302 so as to project
outward from a respective one of the shorter sides 310 of the body
302 radially away from the center thereof. In the third embodiment
compressor, the cylinder liners 36 are of a standard conventional
type having hollow cylindrical bodies, each open at its opposite
ends and continuous around its longitudinal axis over its entire
length. As shown in FIGS. 23 and 25, the cylinder mount 312 for
each cylinder liner 36 has a right-angle bracket structure
including a plate-like rectangular base portion 314 for mounting
flush atop the top face 304 of the body 302 and an annular portion
316 projecting perpendicularly from an end of the base portion 314.
A cylindrical protuberance 318 depends perpendicularly from the
base portion 314 between the end thereof from which the annular
portion 316 projects and an opposite end in a direction opposite
the projection of the annular portion 316. The protuberance 318
fits into a corresponding blind hole 319 extending into the body
302 perpendicularly from the top face 204 thereof at a distance
radially inward from the respective shorter side 310 such that the
base portion 314 of the cylinder mount 312 extends from the
protuberance 318 toward the shorter side 310 to support the annular
portion 316 thereat. The protuberance 318 is hollow with a bore 320
thereof extending through the base portion 314 such that the
protuberance 318 is open at both ends thereof. On each side of the
protuberance 318, a fastener slot 322 is formed in the base portion
314 to extend toward the end thereof from which the annular portion
316 projects away from the opposite end. The slot 322 passes
through the base portion 314 to the bottom surface thereof, but at
a depth below the top surface 324 of the base portion 314, the slot
322 is narrowed and shortened by a continuous flange 325 of
constant width projecting into it. In other words, the slot is
stepped from a first set of larger dimensions to a second set of
smaller dimensions moving from the top face 324 of the base portion
314 toward the opposite bottom face. A pair of spaced apart
threaded blind fastener holes 326 extends into the body 302
perpendicularly from the top surface 304 thereof on each side of
the blind hole 319 so as to align with a respective one of the
fastener slots 322 when the protuberance is lowered into the blind
hole 319. Two threaded fasteners 328 are passed through each slot
322 and threaded into the respective pair of fastener holes 326 to
clamp the cylinder mount 312 to the top face 304 of the body 302 by
engagement of the fastener head with the flange 235 of the base
portion 314 projecting into the slot 322.
[0246] The annular portion 316 of the cylinder mount 312 has a
round central opening 330 extending therethrough about an axis
perpendicular thereto. Like the slots 322 in the base portion 314,
the central opening 330 of the annular portion 316 is stepped,
going from a larger diameter at an outer face 332 thereof opposite
an inner face 334 of annular portion 316 from which the base
portion 314 projects to a smaller diameter at the inner face 334.
Viewed from the outer face side of the cylinder mount 312, this
creates an annular flange projecting into the opening 330 part way
therethrough from the outer face 332 against which one of the
annular end faces 336 of the cylinder liner 36 abuts when the
cylinder liner 36 is urged into the opening 330 from the outer face
side of the cylinder mount 312. A piston 42 is sealingly installed
in the bore or hollow interior of the cylinder liner 36 with the
piston end 46 of a connecting rod 44 pinned thereto to project out
of the cylinder liner 36 through the annular portion 316 of the
cylinder mount 12.
[0247] A cylinder head 338 is fitted over the end of the cylinder
liner 36 opposite the cylinder mount 12 to close off that end. The
cylinder head 338 has three fastener holes 350 extending
therethrough parallel to and equally spaced about its cylinder
receiving opening 352, with three corresponding fastener receiving
holes 354 extending through the annular portion 316 of the cylinder
mount 312 parallel to and equally spaced about the central opening
330 thereof. Three fasteners 356 are passed through the holes 350
in the cylinder head 338 and extended into the holes 354 of
cylinder mount 312 for engagement therewith to clamp the cylinder
liner 336 in place between the cylinder head and mount. The intake
valves 338a and the exhaust valves 338b of the cylinder heads 338
are conventional ball check valves, known to those of skill in the
art, arranged to open and close in response to the pressure
differences between the air within the portion of the cylinder
liner between the cylinder head and piston and the surrounding air
outside this space, just as in a conventional air compressor.
[0248] As illustrated by FIG. 23, a driven gear 358 has a round
cylindrical projection 360 projecting perpendicularly upward from a
top face 362 thereof for fitting into a bore 364 extending through
the driving end 56 of the connecting rod 44 perpendicular to the
length thereof to provide a pivotal connection of the connecting
rod 44 to the driven gear 358. A pin 368 projects into a round
central through hole 370 of the driven gear 358 from therebelow,
the pin 368 also being concentrically received in the bore 320
passing through the base portion 314 and protuberance 318 of the
cylinder mount 312 to provide mounting of the driven gear 358 in a
rotatable fashion on the cylinder mounted 312. To accommodate the
driven gear 358, a central section of the inner face 334 of the
annular portion 316 at the top surface 324 of the base portion 314
has an arcuate recess 372 concentric with the axis of the bore
320.
[0249] As shown in FIGS. 23 and 26, a motor mount 374 of the third
embodiment compressor 300 comprises a round annular plate 376
having a circular central opening 378 therein with four fastener
holes 380 evenly spaced around the opening 378 and extending
through the plate 376. The motor 26 includes a cylindrical housing
382 having two end faces through each of which a driveshaft
projects for rotation. The motor 26 is lowered to seat its bottom
end 384 on the annular plate 376 so that a bottom end 386 of the
driveshaft projects downward through the central opening 378 in the
annular plate 376. Four fasteners 387 are passed through the
fastener holes 380 from beneath the annular plate 376 to engage
with the bottom end 386 of the motor 26. Three legs 388 are secured
to the annular plate 376 at evenly spaced points about the
periphery thereof, each having a projecting portion 389 projecting
downward parallel to the central axis of the central opening in the
annular plate and a plate-like base portion 390 fixed at a bottom
end of the projecting portion and extending perpendicularly
cross-wise thereto. The base portion 390 of each leg 388 sits flush
atop the top surface 304 of the base 302 along and adjacent to the
central segment 308a of a respective one of the longer sides 308
such that a pair of through holes 392 spaced along the cross-wise
base portion 390 align with corresponding blind holes 394 extending
perpendicularly into the base 302 from the top surface 304 thereof.
Fasteners 396 are passed through the holes 392 in the base portion
of each leg 388 to engage with the blind holes 394 of the base 302.
The motor mount 374 and the motor 26 secured to the annular plate
376 thereof are thus secured to the base 302. A fan blade unit 395
is coupled to a top end of the driveshaft projecting upward from
the motor housing 382 to improve air circulation for cooling during
operation of the motor 26.
[0250] A drive gear 396 is fixed to the bottom end 386 of the
driveshaft of the motor 26 and positioned between the three driven
gears 358 at the center of the body 302 above the top face 304
thereof in intermeshing engagement with the driven gears 358.
Driven rotation of the drive gear 396 by the driveshaft of the
motor 26 undergoing rotation when the motor is energized by
connection to an electrical supply, such as a rechargeable battery,
rotates the driven gears 358 about the axes of their pins 368.
Revolution of the projection 360 on each driven gear about the axis
of the respective pin 368, with the connecting rod 44 pivtotally
connected at its ends to the projection 360 and the piston 42,
drives reciprocating motion of the piston 42 within the respective
cylinder liner 36 to effect the intake and compression stroke.
Prior to being engaged with the drive gear 396, the driven gears
358 may be relatively positioned about their respective axes to
ensure consistent timing between the completion of the compression
stroke by one piston and the completion of the compression stroke
by the next piston to so complete compression during operation of
the motor 26 to effect rotation of the drive gear.
[0251] As shown in FIG. 24B, the base 302 not only carries the gas
compressors, defined by the cylinder liners, cylinder heads and
pistons, and the drive system for operation thereof, but has a
hollow interior defined by a series of intersecting bores to
provide a manifold for collecting the air compressed in all of the
cylinder liners for selective discharge through a common outlet.
Extending into each shorter side 310 of the body 302 parallel to
and between the top and bottom faces 304, 306 thereof is a
respective receiving bore 400. An opening end 402 of each receiving
bore at the respective shorter side 310 of the body periphery is
threaded to engage with a correspondingly threaded end 404a of a
ninety degree fitting 404. A barbed end 404b of the ninety degree
fitting 404 has a rubber tube 406 sealingly fitted thereover. A
straight barb fining 407 is sealingly engaged to the opposite end
of the tube 406 and sealingly coupled to the cylinder head 338 of
the cylinder projecting from the same short side 310 of the base
302 in communication with the port of the exhaust valve 338b. Each
exhaust valve of the compressor thus discharges the gas compressed
within the cylinder liner into the respective receiving bore
400.
[0252] As shown in FIG. 24B, the receiving bores 400 do not
intersect one another. Instead, a set of three additional bores 408
are provided, each extending from the central segment 308a a
respective one of the longer sides 308 of the base 302 parallel to
and between the top and bottom faces 304, 306 thereof, and
intersect at the center of the body 302. Each of the receiver and
additional bores is perpendicular to the respective side or side
segment from which it extends. So as to avoid the blind holes 319
from the top surface 304 of the base 302, the receiving bores 400
each extend into the respective shorter side 310 proximate an end
310a thereof and intersect with the additional bore 408 extending
centrally from the adjacent long side 308 between the same adjacent
long side and the center of the body 302. With each receiving bore
400 opening into a respective additional bore 408 and the
additional bores intersecting at the center of the body 302, the
fluidly connected bores thus define a common hollow interior of the
body.
[0253] An opening end 410 of each additional bore 408 at the
central segment 308a of the respective longer side 308 of the body
periphery is threaded to couple with a respective one of a
connection fitting 105 for coupling to a discharge delivery hose, a
pressure switch 412 to operate the motor 26 on the basis of the
pressure detected within the hollow interior of the body 302 and a
plug 414 to close off one of the opening ends 410 of the additional
bores 408. The use of the plug 414 gives the option of connecting
another component if desired. With the plug removed, it may be
desirable to equip the base with a pressure gauge or to provide an
additional connection fitting. For example, with the connection
fitting 105 illustrated in FIGS. 21 and 23 being a female
connection fitting, it may be desirable to remove the plug 414 to
attach a male connections fitting, thereby allowing the user to
select between the two connection fittings depending on the type of
hose to be connected to the compressor 300.
[0254] The hollow interior of the body 302 formed by the
intersecting bores 400, 408 defines a manifold for collecting
compressed air from each of the cylinder liners 36 through the
hoses 406 coupled to the opening ends 402 of the receiving bores
400 and channeling the compressed air to one of the openings ends
410 of the additional bores 408 for discharge through a common
outlet to a compressed air delivery hose adapted for connection to
a pneumatic device. As in the first two embodiments, the manifold
defining feature also acts to carry or support the plurality of
cylinders. The three-cylinder embodiment shown can be used for less
demanding pneumatic applications than an arrangement with more
cylinders, such as the six-cylinder arrangements illustrated in the
first and second embodiments. Alternatively, a larger manifold
defining base may be provided so as to accommodate more gas
compressors.
[0255] With the three gas compressors spaced about the driveshaft
axis, as the piston of one gas compressor completes its compression
stroke by reaching the fully extended position, one of the two
remaining gas compressors is in its compression stroke with its
piston moving toward the fully extended position and the other gas
compressor is in its intake stroke with its piston moving toward
the fully retracted position.
[0256] Each of the three embodiments described above provides a
compressor having more than two gas compressors radially disposed
about the driveshaft within a common plane so as to keep the height
or thickness of the unit down. The compactness of each portable
unit is improved over conventional portable compressors by having
the rigid base or housing that supports the cylinders also act as
the manifold for collecting compressed gas from each cylinder into
the same common receiving space. Suitable materials for the
compressor embodiments described above will be appreciated by those
of skill in the art and include metals and plastics, with plastics
or lighter weight metals such as aluminum helping contribute to the
portability of the compressor by keeping its overall weight down.
As shown by comparing the first and second embodiment compressors
to the third, this portability does not rely entirely on having the
cylinder liners disposed partly within the manifold itself or on
the use of the advantageous, unique compressor valves disclosed
herein, although these features do contribute a significantly
compact and protected substantially enclosed unit.
[0257] As appreciated by those of skill in the art, any of the
compressor embodiments described herein above may be additionally
include a built-in regulator valve installed in a discharge port or
outlet of the compressor to control the pressure of gas delivered
by an air hose coupled to the compressor.
Integral Spider Piston/Conrod Structure
[0258] FIG. 27 shows an alternate connecting rod and piston
structure 500 that may be substituted for the master connecting rod
52, slave connecting rods 44 and pistons 42 of the first or second
embodiment compressors 10, 200. The structure 500 is a single
integral unit having a solid central body 502 having a disc-like
shape with identical top and bottom circular surfaces 504, 506 and
a peripheral wall 508 defining a constant height or thickness of
the body 502. A central bore 510 extends fully through the center
of the body 502 perpendicular to the top and bottom faces 504, 506
thereof so that the structure 500 can be journaled on the crank pin
of the compressor's drive system that revolves about the rotational
axis of the crankshaft about which the crank pin revolves. Six
connecting rods 512 project radially outward from the peripheral
wall 508 of the solid body 502 at evenly spaced points therealong,
each supporting a respective piston 514 at an end opposite the
central body's periphery. Each connecting rod 512 features flexible
portions 518 at opposite ends of a central rigid portion 519 for
connection to the peripheral wall 508 of the body 502 and a face
520 of the piston 514 nearest the body 502. The flexible portions
allow the pivotal-like motion necessary between the connecting rod
512 and each of the body 502 and the piston 514 to convert the
orbital motion of the central body 502 about the axis of the
driveshaft into reciprocating linear motion of the piston within
the cylinder liner. In other words the connecting rod 512, along a
plane normal to the axis of the bore 510 through the body 502 and
thus to the driveshaft axis parallel thereto, can undergo
pivotal-like motion relative to the body 502 and pivotal-like
motion relative to the piston 514. As a single integral piece
formed by molded plastic, the connecting rod and piston structure
500 significantly reduces the number of pieces relative to the
corresponding structure of the first and second embodiment
compressors. This reduces the total number of parts that must be
manufactured and the assembly time needed to produce the
compressor.
[0259] It should be appreciated that the pistons 514 of the
connecting rod and piston structure 500 may be of an unported type,
like that of the first embodiment in which the face of the piston
opposite the connection to the connecting rod is solid, or of a
ported type including an intake valve formed thereon, like that of
the second embodiment. It should also be appreciated that the
number of pieces used in the drive system may similarly be reduced,
although by not as much, by making each connecting rod 512 integral
with only one of the piston 514 and the body 502. For example,
molding the central body 502 and the connecting rods 512 into a
single integral plastic unit with the ends of the connecting rods
512 opposite the body 502 adapted for pinning to separate pistons,
such as in the first or second embodiment, would still reduce the
number of drive system components to be assembled. As another
example, so would molding each connecting rod integrally with its
respective piston with the end of the connecting rod opposite the
piston adapted for pin or keyway based pivotal connection to a
separate central body.
Piston in Valve with LSR Band
[0260] FIG. 28 shows an alternate valve-equipped piston structure
600 that may be substituted for the piston and intake valve of the
second embodiment compressor 200. As can be seen from a comparison
of FIGS. 28 and 8C, the intake valve of the piston structure 600 is
similar to the intake valve formed on each cylinder head of the
first embodiment compressor. The piston 600 features an integral
piston body 602 defining a round cylindrical base 604 having a
drive end face 606 past which a connecting rod 608 extends and a
valve end face 610 opposite the drive end face, an annular wall 612
projecting from the valve end face 610 in a direction opposite the
drive end face 606 flush with the outer periphery 614 of the base
604 and a round cylindrical projecting portion 616 projecting
centrally from the valve end face 610 within a hollow space 618
surrounded by the annular wall 612 and being coaxial therewith. A
plurality of intake ports 620 extend radially through the
cylindrical projecting portion 616 and communicate with channels
622 bored obliquely into the base 604 from the drive end face 606
thereof from radially outward of a centrally located recessed
portion of the drive end face 606 accommodating the pinned
connection of the piston 600 and connecting rod 608. The channels
622 converge toward the radial center of the projecting portion 616
and extend thereinto to communicate with the intake ports 620. With
a seal ring 624 seated within a groove in the outer surface of the
annular wall 612 partially defining the piston's periphery to
provide sealed engagement between the piston 600 and the cylinder
liner in which the piston is disposed, the fluidly connected
channels 624 and the intake ports 620 thus define a passage fluidly
communicating opposite sides of the sealing engagement between the
piston and cylinder liner.
[0261] A flexible resilient band 78 like that used in the intake
valve of the first embodiment and the exhaust valve of the first
and second embodiments is disposed about the projecting portion 616
to seal tightly over the intake ports 620 until, during the intake
stroke of the piston, the pressure of the ambient air outside the
cylinder liner exceeds that therewithin enough to stretch the
resilient band about the projection portion 616 to uncover the
intake ports 620 and allow the ambient air to flow from outside the
cylinder liner, into the channels 624 from the drive end face 606
through the intake ports 620 into the enclosed area between the
piston and the end of the cylinder liner closed by the exhaust
valve. As the pressure increases within this area under entry of
the ambient air, the resilient band eventually tends to retighten
around the projecting portion 616 to once again seal off the intake
ports 620. During the compression stroke, the increasing pressure
within the cylinder liner acts only to further retain the resilient
band 78 of the intake valve in this closed sealing position over
the intake ports 620.
[0262] A flange 626 disposed at the end of the projecting portion
616 opposite the valve end face 610 of the cylinder body's base 604
projects radially outward from the projecting portion 616 around
the full circumference thereof to define a seat or groove extending
around the projecting portion 616 between the flange 626 and the
valve end face 610 to keep the resilient band 78 in position about
the ported projecting portion 616. The flange 626 blocks the
resilient band 78 from moving axially along the projecting portion
616 when to ensure that when the band resiliently retightens around
the projecting portion, it will be in position to once again cover
the intake ports 620.
[0263] It should be appreciated that the first embodiment
compressor 10 may be modified to remove the cylinder heads 48 and
have the outer periphery of the compressor, as defined by the
exterior wall 16 of the housing, closed about the cylinder liners
36, and instead use the piston mounted intake valves of the second
embodiment compressor 200 or the alternate piston structure 600.
This would of course require that at least one opening be provided
to communicate the environment surrounding the compressor with the
crank chamber surrounded by the interior wall 30 of the housing 12,
for example by extending through the lid or cover 14 opposite the
lid or cover 16 to which the motor 26 is mounted.
Pumps
[0264] Although the embodiments described herein above are each
presented in terms of an air compressor, it should be appreciated
that the unique and advantageous features may be useful not only in
the context of gas compressors, but also in the context of a
reciprocating pump used to convey a fluid from areas of lower
pressure to higher pressure with little or no compression of the
fluid. For example, a more compact piston-based multiple-cylinder
reciprocating pump may be produced using the ideas of having a base
or frame not only carry the cylinders but also defining a manifold,
or even disposing the cylinders partly within the manifold. The
unique valve arrangements of the compressors described above will
offer the same advantages within a pump. The compressors disclosed
above may be used as submergible pumps, the intake of the
compressors from the surrounding ambient air being analogous to the
intake of a pump from the surrounding fluid in which it is
submerged. Alternatively, the unit may be connected to a fluid
source fluidly sealed to the unit to communicate with the intake
ports.
[0265] For example, a pump of similar structure to the first and
second embodiment compressors may be used to pump water out a gas
well or pump gas into the earth in underground storage reservoirs.
Components of such a pump may be produced using inert epoxies
rather than aluminum or another metal to prevent the potential for
reaction when in contact with fluids or solutions, and the LSR
based valves may offer improved resistance to exposure to
abrasive-containing fluids. The relatively high efficiency of the
pump allows powering thereof by a battery or photocell, thereby
allowing use in areas where there may not be an existing electrical
supply. For example, the pump may be used at remote well sites
where electrical transmission lines have not been set up, thereby
avoiding or delaying the high cost and environmental impact
associated with the installation of such a long-distance electrical
transmission system. As an example, where more pumping power than
that provided by a single unit is required to remove water from a
well, a series of pumps having housings resembling those of the
first or second embodiment compressors may be mounted on a single
driveshaft extending through each one with the discharge conduit of
one pump connected to the intake of the next. The pumps would be
lowered into the well on the driveshaft to pump fluid through the
series of pumps upward from one to next and eventually to the
surface. The sealing rings of the pistons used in such a pump may
use polyetherketone on the basis of its known relatively high
chemical resistance to increase the life of the pump.
Carrying Handle
[0266] FIG. 29 shows a portable compressor assembly 700 featuring a
compressor 702 similar to that of the second embodiment compressor
described herein above. The compressor 702 is mounted at one end of
a hollow cylindrical tube 704 of circular cross section defining a
carrying handle having a rechargeable battery pack 706 mounted at
the opposite end thereof. A motor is contained within a cylindrical
housing 712 of circular cross section extends parallel to the
carrying handle 704 therebelow and is operationally connected at
its opposite ends to the battery pack 706 and the compressor 702. A
power adapter or battery charger 714 can be releasably mounted to
and electrically coupled with the battery pack 706 as needed to
charge the battery or run the motor from a conventional AC
electrical socket. The assembly 700 is compact, easy to carry by
hand and well balanced due to the relative positioning of the
components.
[0267] As shown in FIGS. 29 and 30, the compressor 702 differs from
the second embodiment compressor in that it features only three
cylinder liners 36 and has a different outer peripheral shape. The
receiver housing 716 can be considered to have two portions, a main
bottom portion 718 and a top projecting portion 720, divided by
imaginary line 722 in FIG. 31 (the words top and bottom being used
herein in relation to the positioning and orientation shown in the
particular figures being referenced). This three cylinder
arrangement results in the main portion of the receiver housing 716
having a six sided shape different than the shape of the receiver
housing 202 of the second embodiment compressor, which is somewhat
like a regular hexagon with equal length sides but with the sides
somewhat curved and the corners rounded, and more similar to the
peripheral shape of the manifold-defining base 302 of the third
embodiment compressor 300, but without the longer sides being
recessed inward from the shorter sides at which the cylinders are
disposed. The main portion 718 of the receiver housing 716 of the
compressor 702 thus has a peripheral shape of six sides, three
equal length longer sides alternating about the periphery with
three equal length shorter sides as if formed by a triangle having
each of its corners out away along a straight line between the two
sides the previously intersected to define the corner. The three
cylinder liners 36 are evenly spaced about the crank housing 724
disposed within the central opening of the receiver housing,
defined by the inner peripheral wall 726 of the main portion 716,
to project from the crank housing 724 into the receiver housing 716
toward each of the shorter outer peripheral sides of the main
portion 716 thereof. As in the second embodiment, a channel-like
manifold extends around the central opening in the receiver housing
716 and is sealed around all of the cylinder liners 36 at the valve
ends thereof to define the receiver space into which compressed air
is discharged from each cylinder liner during the compression
stroke of the piston sealed therein.
[0268] The projecting portion 720 of the receiver housing 716 is
rectangular in shape, projecting perpendicularly upward from the
flat top of the main portion 718 at imaginary line 722 in FIG. 31.
Each of the two halves 728, 730 of the receiver housing 716, mated
face-to-face in a sealed arrangement as illustrated by line 732 of
FIG. 29 in a manner similar to those of the second embodiment, is
integral, meaning that the main and projecting portions of each
half are defined by a single piece of material. As shown in FIG.
31A, a hollow linear cylindrical channel 733 extends into the
projecting portion 718 vertically upward along a central axis
thereof from the annular manifold defining channel in the main
portion 718 in a direction perpendicular to the imaginary border
722 between the two portions. Like the annular manifold-defining
channel of the second embodiment, the linear channel and annular
channel of the compressor 702 are each formed by cooperating
grooves or recesses in the two halves 728, 730 of the receiver
housing 716. Due to the intersection of the annular and linear
cylindrical channels, the outer seal disposed around the annular
channel does not form a closed circle, but instead arcs around the
annular channel from adjacent one side of the linear cylindrical
channel to the other and extends upward along both sides of the
linear cylindrical channel toward the top face 734 of the receiver
housing 716 to close around the upper limit of the linear
cylindrical channel 733.
[0269] As shown in FIG. 31A, a cylindrical bore 735 extends
perpendicularly through the cylindrical channel 733 at the
projecting portion 720 right through the receiver housing from the
outer non-mating face of one half 728 thereof to the outer
non-mating face of the other half 730, that is, from the handle
side of the compressor to the side opposite the handle 704. The
cylindrical channel 733 extending from the annular
manifold-defining channel within the main portion 718 of the
receiver housing 716 ends at its intersection with the cylindrical
bore 735, forming a T-shaped juncture 737 between the top face of
the 734 of the projecting portion of the receiver housing and the
parallel imaginary top end 722 of the main portion 718. The bore
735 corresponds most closely to the gas passageways of the first
and second embodiment compressors, acting to form an outlet from
the manifold, or receiver, defined within hollow interior of the
receiver housing, but differs in that it extends through both
halves of the housing. At the outer face 736 of the outer half 728
of the compressor's receiver housing 716, opposite the handle 704
and motor housing 712, the bore 735 is threaded to receive and
sealingly engage a conventional female quick connect fitting 105 to
allow connection of an air hose equipped with a corresponding male
half at one end. At the inner face 738 of the inner half 730 of the
receiver housing 716, nearest the handle 704 and motor housing 712,
the bore 735 is threaded to receive and sealingly engage with a
correspondingly threaded end of the hollow cylindrical carrying
handle 704. By this arrangement, the hollow interior of the
cylindrical carrying handle 704 is in fluid communication with the
manifold or receiver, which receives compressed gas from the
cylinder liners 36 during operation of the compressor 702, via the
intersecting cylindrical channel 733 and bore 735.
[0270] The end of the hollow carrying handle 704 opposite the
compressor 702 is passed through a suitably sized hole in a
supporting plate 741 and is threadingly engaged with a threaded
bore 739 communicating with a hollow interior of an otherwise
enclosed control box 740. The hollow interior of the control box
740 is thus in fluid communication with the hollow interior of the
handle 704, the bore 735 and cylindrical channel 733 in the
projecting portion 720 of the receiver housing 716 and the annular
channel within the main portion 718 of the receiver housing 716.
These interconnected areas thus define a single enclosure for
receiving compressed air during operation of the compressor 702 and
having a single outlet or discharge at the female air hose quick
connect component 105. A pressure switch (not shown) is mounted
within the hollow interior of the control box 740 and wired to an
on/off switch 742 mounted on a top surface 744 thereof.
[0271] The supporting plate 741 has a similar but slightly smaller
peripheral shape as the receiver housing 716 of the compressor 702,
the hole in the plate 741 through which the handle 704 passes
through being situated in the part of the plate corresponding to
the projecting portion 720 of the compressor's receiver housing
716. Threaded fasteners 741a pass through the plate 741 from the
side thereof into threaded receivers 740a in the control box at the
face thereof past which the handle extends for engagement
therewith. The portion of the plate 741 corresponding to the main
portion of the compressor's receiver housing projects downward from
the plate's attachment to the control box 740 to support the motor
housing 712. Beneath the control box 740 is the rechargeable
battery pack 706 releasably coupled to both the control box 740 and
the motor housing 712 to establish electrical connection with the
motor within the motor housing 712 via the on/off switch 742 and
pressure switch of the control box 740 via circuitry known to those
of skill in the art.
[0272] With the on/off switch 742 set to on, the battery pack 706
is electrically connected to the motor within the motor housing 712
when the pressure measured by the pressure switch in the control
box 740 is below a predetermined limit. The driveshaft of the
motor, extending along the cylindrical housing 712 surrounding it
parallel to the handle 704, projects concentrically into the
central opening in the crank housing 724 and connects to the
crankshaft of the compressor 702 so that powering the motor drives
rotation of the crankshaft to operate the compressor. A
pneumatically driven device can be fluidly connected to the outlet
defined by the second cylindrical channel 735 at the outer face 736
of the compressor 702 via an air hose coupled with the female quick
connect component 105 for operation by the compressed air provided
from the portable compressor assembly 700.
[0273] In the embodiment of the portable compressor assembly 700
shown in FIGS. 29 to 31, the control box 740 has the same size and
shape as the projecting portion 720 of the compressor 702 and the
battery pack 706 has the same size and shape as the main portion
718 of the compressor 702. When assembled, the control box sits
atop the battery pack 708 on the flat top surface 746 thereof as
defined by one of the shorter sides of the six-sided battery pack.
With the battery pack 706 engaged to the motor housing 712 and the
control box 740, which is threaded to the corresponding externally
threaded end of the hollow cylindrical handle 704, the combined
battery pack 706 and control box is in the same orientation as the
equally sized and shaped compressor 702, providing a balanced,
somewhat symmetric appearance. Having the combined weight of the
battery pack 706 and control box 740 being similar to the weight of
the compressor 702 may also contribute to a more balance weight
distribution across a center plane of the cylinder, depending on
the weight distribution within the motor housing 712.
[0274] FIG. 30 shows the portable compressor assembly 700 with the
detachable battery pack 706 removed. The removable mounting of the
battery pack allows for substitution of a drained battery pack for
a charged one, easy replacement of an old, damaged or defective
battery pack and charging of a battery pack remote from the rest of
the assembly. As shown in FIGS. 30 and 30A, the battery pack 706
has a pair of spaced-apart electrical contacts 748 projecting
normally from the flat top surface 746 thereof for contact with a
corresponding pair of contacts within a pair of recesses 750
projecting normally upward from the otherwise flat bottom surface
752 of the control box 740 into the hollow interior thereof. The
sizing and spacing of the battery pack contacts 748 and the control
box recesses 750 are such that the battery pack contacts 748
project into the recesses 750 and contact the control box contacts
therein when the control box 740 is lowered onto the battery pack
706 to bring the top surface 746 of the battery pack and the bottom
surface 752 of the control box into flush face-to-face contact.
[0275] To lock the battery pack and control box together when the
two components are brought together in such a manner, a pair of
resiliently biased latches 754 project downward from the bottom
surface 752 of the control box 740 inward of the opposite ends
thereof. The latches 754 are biased into the parallel vertical
positions shown in FIG. 30a where each extends normal to the bottom
surface 752 of the control box, but can be forced to converge
toward one another away from the control box. When the control box
740 is lowered onto the battery pack, the latches depend into
openings or recesses in the upper surface 746 thereof and sloped
surfaces 756 within these openings forcing the latches 754 slightly
together out of the biased positions as they move further downward
into the openings. Once the latches pass the bottom end of these
surfaces 756 they bias away from one another back to their parallel
positions to catch a ledge defining end of each latch on the bottom
edge of the respective sloped surface, which prevents inadvertent
withdrawal of the latches from the openings and separation of the
control box and battery pack. To detach these components, the user
simultaneously depress two push buttons 758 disposed at the
opposite ends of the control box 740, that is the ends thereof on
opposite sides of the longitudinal axis of the handle 704, to once
again force the latches out of their biased positions to move
toward one another and disengage from about the bottom edges of the
sloped surfaces 756 so that they can be withdrawn from the
openings. Releasable latching arrangements of this type are known
for connection of rechargeable battery packs to portable electrical
tools, such as hand held cordless drills.
[0276] An additional pair of electrical contacts 760 in the form of
parallel elongate rails extending along an inner face 762 of the
battery pack are sized and shaped to slide upward into a
corresponding pair grooves 763 provided in a respective end face
764 of the motor housing 712. As shown in FIGS. 29 and 30c, a
flange 761 projects radially outward from the motor housing 712
about the end face 764 thereof to allow fasteners 761a past through
this flange 761 to engage with the supporting plate 741 at points
circumferentially spaced about the motor housing 712. The plate 741
so supporting the motor housing is of sufficient thickness to have
recesses 741b in a face 741c of the plate opposite the motor
housing 712 so that the heads of the fasteners 761a are recessed
from this face 741c, which thus remains flat and smooth for sliding
of the battery pack 706 therealong into and out of engagement with
the control box 740, A slot 741d extends upward from the bottom of
the plate 741 to expose the parallel grooves 763 in the end face
764 of the motor housing 712 extending upward from the bottom
thereof for receipt of the rail-like electrical contacts 760 of the
battery pack 706, which project far enough from the end face 762 of
the battery pack 706 to extend through the slot 741d of the plate
into the grooves 763 of the motor housing 712 as the battery pack
706 is lifted upward along the outer face 741c of the plate 741
into engagement with the control box 740. The flange 761 of the
motor housing 712 does not completely encircle the end face 764
thereof, but stops on each side of the pair of grooves 763 so as to
not project therebelow and block sliding access thereto by the
battery pack contacts 760.
[0277] Like the recesses 750 in the control box 740, the grooves
763 in the motor housing 712 contain electrical contacts positioned
for physical contact with the rail-like electrical contacts 760 of
the battery pack 706 once sliding thereof up into full latching
engagement with the control box 740 is completed, the motor housing
contacts being wired to the motor for powering thereof. The
electrical contacts 748 and 760 on the top surface 746 and inner
face 762 of the battery pack 706 respectively are wired therein for
electrical connection of the at least one rechargeable battery or
cell within the pack to the motor in the motor housing 712, via the
on/off and pressure switches in the control box 740.
[0278] The motor housing 712 is secured to the compressor 702 by
threaded fasteners 765 fed through another flange 766 projecting
radially outward from the periphery of the round cylindrical motor
housing 712 at an end thereof opposite the battery pack 706 to
engage with threaded blind-holes 767 extending into the inner half
of the receiver housing 716 from the inner face 738 thereof. As
shown in FIG. 31, the motor housing securing fasteners 761a, 765 of
the illustrated embodiment are provided in pairs at each end of the
motor housing 712, the fasteners of each pair being spaced apart
along a respective one of the longer sides of the six-sided main
portion 718 of the receiver housing 716.
[0279] A fan is shown schematically at 768 in FIG. 30, mounted
within the interior of the motor housing 712 proximate the flanged
compressor-end thereof, which is left at least partially open so as
to fluidly communicate the hollow interior of the motor housing 712
with the crank chamber of the compressor, as defined by the crank
housing 724 thereof. The fan 768 is mounted on the driveshaft of
the motor, shown schematically at 771, so that when the motor is
powered, rotation of its driveshaft not only runs the compressor
via the crankshaft thereof but also rotates the fan so as to
encourage air flow into the crank chamber from the surrounding
environment through an opening or inlet 769 in the crank housing
lid. Although the opening 769 shown is shaped like those of the
second embodiment compressor, this opening or inlet may be given
the shape of those featured on the cylinder heads of the first
embodiment, with the flared trumpet-like outer peripheral shape of
a velocity stack inlet, to encourage an increase in velocity to
bring an increased volume of air into the crank chamber
[0280] A portion of the air being drawn into the crank chamber
enters the cylinder liners 36 via the piston-mounted valves, just
as described for the second embodiment compressor, for compression
therein, while the reminder of the airflow continues into the motor
housing and past the fan 768. Air flows around the motor between it
and the surrounding housing 712, continuing along the housing 712
to circumferentially spaced vents or openings 770 in the housing
wall proximate the end face 764 of the motor housing 712 at which
the supporting plate 741 is disposed. The induction fan 768 thus
assists the intake of the compressor by encouraging airflow
thereinto while also providing a stream of air past the motor to
help dissipate heat therefrom and discharge it from the motor
housing 712. The motor mounted concentrically within the housing
712 features a round cylindrical casing that may have heat
dissipating fins projecting outward therefrom toward the
cylindrical housing 712 closed about the motor casing to improve
heat transfer from the motor to the fan induced airflow
therepast.
[0281] FIGS. 29 and 30 show the battery charger 714 that is
releasably connectable to the rechargeable battery pack 706,
whether attached to the control box 740 or not, for charging
thereof. The charger has a casing of the same general shape and
size of the battery pack 706 and the main portion 718 of the
compressor's receiver housing 716 to provide a consistent
appearance among the components of the portable compressor assembly
700. A pair of projecting electrical contacts 772 are provided on
an end face 774 of the charger casing to cooperate with
corresponding contacts mounted in recess 775 in an end face 776 of
the battery pack 706 opposite the motor supporting plate 741 when
these end faces are brought flush together along an axis
perpendicular to them, just like the contacts cooperating between
the battery pack 706 and the control box 740. Two resilient latches
or clips 778 project from the charger casing in biased positions
along parallel axes normal to the end face 774. A width of each
clip extends obliquely downward away from a top center surface 779
of the charger casing along a respective sloped side surface 780
extending downward therefrom. The latches or clips 778 are forced
out of their parallel biased positions to diverge away from the end
face 774 of the charger casing and the charger is pushed into flush
face-to-face contact with the battery pack 706 to connect the
electrical contacts of the two components. With the charger 714 so
positioned relative to the battery pack 706, the latches or clips
778 return to their biased positions with latching ends being
disposed just past the end face 762 of the battery pack 706 at
which the motor housing 712 is disposed. The ledges or shoulders
formed at the latching ends engage about the edges defined between
the motor-side face 762 of the battery pack 706 and the sloped side
surfaces 782 thereof extending downward and away from the battery
pack's top surface 746. This engagement prevents withdrawal of the
battery pack along the axis normal to the mated surfaces of the
battery pack and charger. The non-vertical edges to which the clips
or latches 778 engaged also acts to resist downward sliding of the
charger 714 off the battery pack 706. Fall of the charger down from
the battery pack is also resisted by contact of the bottom ends of
the charger's electrical contacts 772 on shelves defined by closed
bottom ends of the corresponding recesses 775 in the battery pack's
outer end face 776.
[0282] An electrical cord 777 coupled to the charger 714 includes a
conventional plug 778 for connection to a conventional AC outlet,
and the charger 714 and battery pack 706 are configured to allow
either one of charging the battery pack when drained or powering
the DC motor via the power and pressure switches when the cord 777
is connected to an appropriate external power source.
[0283] FIG. 32 shows an alternate embodiment portable compressor
assembly 784 that has a similar appearance to the portable
compressor assembly 700 of FIGS. 29 to 31. The alternate embodiment
portable compressor assembly 784 however, features not one, but two
reciprocating compressors 702, 702', one at each end of the hollow
carrying handle 704. The two compressors 702, 702' are nearly
identical, except for a few differences in the projecting portions
702, 702'. Compressor 702 is identical to the other portable
compressor assembly detailed herein above. Compressor 702' differs
however in that the cylindrical bore fluidly communicating with the
hollow cylindrical carrying handle 706 is not equipped with a
female quick connect fitting 105, but rather is either plugged at
the outer non-mating face of the outer half 728' of the receiver
housing 716' or does not extend fully through this face at all. The
annular manifold-defining channels of the two compressors 702, 702'
are fluidly communicated with on another through the
conduit-defining hollow carrying handle 704 via the cylindrical
bores and cylindrical channels of the two compressors for discharge
through the single outlet defined at the female quick connect
fitting 105. The on/off switch 742 is mounted at the top surface
734' of the second compressor 702' in the same position as the
other embodiment, and wired to a pressure switch (not shown)
communicating with the common enclosed space fed by the cylinders
of the two compressors,
[0284] The motor housing 712' is connected to each of the
compressors 702, 702' by flanges and fasteners at each end, as
described for the single compressor of the other embodiment, with
each end being open in fluid communication with the crank chamber
of the respective compressor. The motor contained within the motor
housing 712' is centrally mounted therealong and has the driveshaft
extending from both of its ends, each end of the driveshaft
connected to the crankshaft of a respective one of the two
compressors. Two fans are mounted on the driveshaft for driven
rotation thereby, each between the motor and the respective
compressor. The openings 782' in the peripheral wall of the motor
housing 712' and circumferentially spaced thereabout are located
centrally along the housing 712', that is, spaced about the motor.
Each fan operates in the same way to draw air into the crank
chamber of the respective compressor through the inlet defined by
the openings in the crank housing lid so that a portion of the air
flow is drawn into the cylinders for compression and a remaining
portion of the air flow continues into the motor housing 712' past
the fan to the motor. The air flows from the two fans meet at the
longitudinal center of the motor housing 712' in the space between
the motor and the surrounding peripheral wall of the housing and
disperse outward through the vents or openings 782'. Convection
heat transfer occurs from the motor to these air flows so that heat
is carried out of the housing through the openings 782' to cool the
motor and housing.
[0285] As shown in FIG. 32, the alternate embodiment portable
compressor assembly 784 features a rectangular power device 786
that not only delivers electricity to the motor disposed within the
motor housing 712, but also acts to define a base of the assembly.
The two compressors sit atop the rectangular power device 786
carrying the motor housing 712' between them. The power device is
wired to the motor via the on/off switch 742 and the pressure
switch, which may be mounted to compressor 702' in proximity to the
on/off switch. The power device includes a conventional removable
electrical cord 777' with a male plug 778 for connection to a
conventional AC electrical socket and a female end 788 for manually
releasable connection to male prongs provided within a recess 790
in the outer shell of the power device 786. The power device may be
an adapter for converting the electricity from the AC external
power supply for use with the DC motor. Alternatively, the power
device may include at least one rechargeable battery or cell with a
built in charger using the removable cord 777' for connection to an
external power supply, or may be a unit capable of either charging
its internal rechargeable battery or running the motor when
connected to an external power supply. The power device may be
manually detachable for releasable connection to the compressors or
motor housing to allow quick and easy replacement thereof by known
releasable fastening methods, for example by the use of flexible
resilient clips similar to those used to connect the battery
charger and battery pack of the other portable compressor assembly
embodiment for engaging between the compressors 702, 702' and the
power device 786, in which case mating male (projecting) and female
(recessed) electrical contacts also similar to those taught above
can provide breakable electrical contact between the detachable
components.
[0286] The assemblies of FIGS. 29 to 32 are easy to carry and
provide a relatively compact arrangement, especially when used with
compressors of the type described herein above where the cylinders
extend radial to the driveshaft axis at positions spaced thereabout
in a common plane perpendicular to this axis. The relatively high
efficiency of the first and second embodiment compressors means
that the handle assembly can be used to provide a portable unit
comfortably carriable in one hand that can be easily transported
from site to site and is capable of use in higher demand
applications than previously available portable units. Other
portable compressors may be similarly equipped with a handle
carrying a battery pack or additional compressor at the opposite
end and adapted to have its motor carried between the ends of the
handle.
Electronic/Pneumatic Tool System
[0287] FIG. 37 schematically illustrates a portable tool system 800
that offers a significant level of portability and flexibility,
particularly when using any of the three compact compressor
embodiments described herein above, which as also described above,
may be carried in a backpack, bag, mesh sack or perforated
container or on a leg strap or belt. The system 800 features a
compressor 802 driven by a compressor motor 804, which is wired to
a rechargeable battery pack 806 via a pressure switch 808 in a
conventional manner to run the motor 804 in response to the demand
for compressed air. A pneumatic tool 809 is connected to the
compressor via an air hose for selective operation. A selector
switch 810 is wired between the battery pack 806 and the pressure
switch 808, the switch also being wired to electrical connections
for selective coupling with an electric tool 812. The switch 810
has an off position, a pneumatic-tool-on position and an
electric-tool-on position in which the battery pack is electrically
isolated, connected to the pressure switch and motor, and connected
to the electric tool respectively. The system 800 is set to off
when not in use, or set to power one of either the pneumatic tool
or the electric tool.
[0288] FIGS. 33A to 33C show three hose structures each adapted for
use in the portable tool system 800 to deliver both air to the
pneumatic tool 809 and electricity to the electric tool 812 so as
to define a single power delivery unit capable of connection to
both pneumatic and electric tools.
[0289] FIG. 33A shows a first hose 820 featuring a flexible tube
822 of electrically insulating material defining an airway through
which compressed air is delivered from the compressor to the
pneumatic tool. A first flexible conductive layer 824 is formed by
a mesh of conductive material wrapped around the outer periphery of
the flexible tube 822 to extend along the length thereof from one
end of the hose to the other. A middle layer 826 of electrically
insulating material is extends about the first conductive layer
824, to separate and electrically isolate the first conductive
layer 824 from a second conductive layer 828 of flexible conductive
mesh closed around the middle insulating layer 826. Finally, an
exterior cover 830 of electrically insulating material covers the
second conductive layer 828 to form the external periphery of the
hose 820. The alternating layers of insulating and conducting
materials maintain the necessary electrical isolation of the
conducting layers to prevent shorts thereacross while also covering
the conductors both inside and outside the hose 820.
[0290] FIG. 33B shows a second hose 840 also having a hollow
flexible tube 842 through which air is delivered, but instead of
alternating conducting and insulating layers, having a first
conductive wire or strip 844 and a second conductive wire or strip
846 spiraled around the flexible tube 842 in a parallel
spaced-apart fashion between opposite ends of the hose 840. The
parallel spiraled arrangement gives the appearance of stripes
having the repeating pattern: first conductor, space, second
conductor, space; extending along the flexible tube 842, where each
"space" stripe is an uncovered portion of the flexible tube 842.
The spacing between the spiraled conductors electrically isolates
them while allowing a greater degree of flexibility in the
resulting hose structure. To ensure the conductors do not make
contact and create a short during flexing of the hose, each
conductor has its own outer insulating layer. Like in the first
hose 820, an outer insulating layer 848 covers the conductive
layers and flexible tube to define the outer periphery of the hose
840, protect the layers beneath it and prevent contact with any
conductor from outside the hose. The flexible tube 842 prevents
contact with any conductor from inside the hose.
[0291] FIG. 33C shows a third hose 860, in which a hollow flexible
tube 862 has a first conductor 864 and a second conductor 866
extending adhered thereto to extend along the flexible tube 862 in
diametrically opposite positions. Each conductor is in a band shape
of significant width spanning just under half of the flexible
tube's circumference so as to leave diametrically opposed gaps 866
of uncovered tube between the two conductors, each gap defining a
strip of insulative spacing or separation extending along a
respective side of the flexible tube. It is conceived that the two
conductors may be formed of foil, conductive ribbon or a conductive
coating adhered to the flexible tube. The width of the form fitting
conductors adhered to the flexible tube may be varied to change the
width of the insulative strips or gaps extending along the tube,
for example to increase the gap width to better prevent inadvertent
shorting between the two conductors. Again, an outer insulating
layer 868 covers the conductive layers and flexible tube to define
the outer periphery of the hose 860, protect the layers beneath it
and prevent contact with any conductor from outside the hose
[0292] FIGS. 34A and 34B show male and female halves of an
electrical and pneumatic coupling respectively, the halves each
having an overall shape similar to the corresponding half of a
conventional air hose quick connect pneumatic coupling. FIG. 35
shows the two halves engaged together.
[0293] The male connector 900 has a plug tip 902, plug body 904 and
a threaded end 906 opposite the plug tip 902. As in a conventional
air hose quick connect, the hollow cylindrical plug tip 902 is in
fluid communication with a central bore extending longitudinally
through the entire male connector 900 to allow air flow
therethrough and the plug body 904 is contoured or shaped to define
a ball groove or recess 908 between two bosses 910, 911. The male
connector 900 is different than that of a conventional air hose
quick connect in that the plug body 904 includes a first tubular
conductive portion 912 concentrically disposed partially within a
second tubular conductive portion 914 with an insulating layer 916
extending entirely about the first conductive portion between the
two conductive portions to electrically isolate them. The first
conductive portion 912 projects past one end of the second to
support the plug tip 902. When fitted on one end of one of the
hoses 820, 840, 860, each of the conductors of the hose is
electrically connected to a respective one of the plug body
conductive portions 912, 914.
[0294] The male connector 900 on one end of the hose is matable
with a female connector 920, of the type shown in FIG. 34B, engaged
to the compressor outlet. Like that of a conventional air hose
quick connect, the female connector 920 features a socket body 922
having a central bore therethrough extending the full length of the
female connector from an interior threaded end 924 thereof. Over an
end of the socket body 922 opposite the threaded end 924 is a
hollow cylindrical sleeve 926 extending concentrically about the
socket body 922 and arranged for limited sliding therealong. The
sleeve 926 is biased toward the end of the socket body 922 opposite
the threaded end 924 by a spring 928 mounted between shoulders 930,
932 on the exterior of the socket body 922 and the interior of the
sleeve 926 respectively, limiting an annular spring-receiving space
therebetween. As in a conventional air hose quick connect, bearing
balls 934 are spaced about the socket body within apertures 936
through the wall thereof that taper toward the socket body
interior. A groove or recess 938 extends about the sleeve in the
interior surface thereof at a height just above the balls 934. The
balls 934 project into the interior of the socket body 922 far
enough to block motion of the boss 910 of the male connector 900
nearest the plug tip 902 past the bearing balls 934 further into
the bore of the female connector 920, until the sleeve 926 is
pulled down toward the threaded end 924 to align the sleeve's
recess 938 with the bearing balls 934 to allow them to move
radially outward as the boss 910 of the male connector 900 is moved
therepast. The plug tip 902 of the male connector enters a
receiving space in the female connector's bore and the sleeve 926
is released back to its spring biased position against a flange or
shoulder 940 formed at the end of the socket body 922 opposite the
threaded end 924. The release of the spring biased sleeve 926
forces the bearing balls 934 radially inward as they leave the
recess 938 in the sleeve 926 to project into the ball groove 908 of
the male connector 900 to lock it in engagement with the female
connector by obstructing withdrawal of the boss 910 past the
bearing balls 934.
[0295] The female connector 920 differs from a conventional one in
that a second set of bearing balls 950 are provided in a second set
of tapered apertures 952 spaced about the socket body's
circumference above the first set of bearing balls 934, that is on
a side thereof opposite the threaded end 924. A second recess 954
is provided in the sleeve's interior wall similarly spaced above
the first recess 938 so as to be situated just above the second set
of bearing balls 950 with the sleeve in the biased position shown
in FIG. 35. A slight narrowing of the second conductive portion 914
of the male connector 900 is shown at 956. The bosses 910, 911
defining the groove 908 of the male connector are formed
respectively at the ends of the first and second conductive
portions 912, 914 thereof nearest the plug tip 902. The narrowing
956 of the second conductive portion 914 occurs between the boss
911 and the threaded end 906 of the male connector 900. The second
set of bearing balls 950 in the female connector 920 cooperate with
the second recess in the sleeve 954 and the narrowing 956 of the
second conductive portion 914 of the male connector 900 in the same
way as the first set of bearing balls 934 do with the first recess
938 in the sleeve 926 and the ball groove 908 of the male connector
900. Each set of bearing balls is thus in contact with a respective
conductive portion of the female connector 920 when in its radially
innerwardmost position, that is with the sleeve 926 in its spring
biased position distal to the threaded end 924.
[0296] Each set of metal bearing balls 934, 950 are in contact with
a respective conductive portion of the female connector 920 when
biased into their radially inwardmost positions projecting into the
socket body interior to contact the respective conductive portion
of the male connector 900. This may be achieved for example, by
forming the socket body 922 of electrically insulating material and
having a continuous band of conductive material coated on the
socket body 922 about its outer periphery at each set of apertures
retaining the bearing balls as shown in FIG. 36. The conductive
bands are electrically isolated from one another by their
separation along the insulative socket body 922 and the bands are
electrically linked to the selector switch 810 and battery pack
806. Grooves 960, 962 extending along the socket body 922 in the
exterior wall thereof allow laying of wire or other conductive
material or coating of the socket body within the groove along the
exterior of the socket body without interfering with the fitting of
the male connector 900 within the female connector 920 or the
sliding of the sleeve 926 along the socket body 922. Each band of
conductive coating may be recessed slightly into the exterior
periphery of the socket body 922 as shown for band 966 in FIG. 35A
so as not to project outward from the rest of the socket body 922
and interfere with sliding of the sleeve 926 therealong. The figure
also illustrates how connection between the conductive bearing ball
950 and band of coating 966 is established by having the coating
material cover the sloping peripheral wall of the aperture so that
the ball is held against the coating by the sleeve in the biased
position.
[0297] The grooves 960, 962 extend from the conductive bands 964,
966 respectively toward the internally threaded end 924 of the
socket body 922 for electronical connection to the selector switch
810 near that mounting end of the female connector. For example,
connection ends 960a, 962a of the conductor filled grooves 960, 962
opposite the bands 964, 966 and nearest, but spaced along the
socket body 922 from, the threaded connection end 924 may service
as solder connection points for leads from the battery and switches
to establish selective electrical connection to the bands 964, 966
and bearing ball sets 934, 950 while ensuring electrical isolation
from the compressor housing coupled to the socket body 922 at the
threaded end by a suitable threaded fitting, as the housing or
fitting may be made of conductive material. A break 968 in the
conductive band 964 connecting the bearing balls of the first set
934 allows passage of a conductor past that band to the band of the
second set of bearing balls 950.
[0298] When the male connector 900 is engaged with the female
connector 920, the contact between the conductive bearing ball sets
934, 950 of the female connector 920 and the respective conductive
portions 912, 914 of the male connector 900 connects the conductors
of the hose 820, 840 or 860 to the switch. At the opposite end of
the hose is another female connector 920 wired to the conductors of
the hose and engagable to an electric tool equipped with another
male connector 900 having its conductive portions wired to the
electric drive system of the tool. With the switch 810 set to
electric-tool-on and the tool activated by its switch or trigger, a
circuit is closed from the battery 806, through the switch 810,
through the male/female coupling at the compressor, through the
hose and through the male/female coupling at the electric tool for
operation thereof.
[0299] Alternatively, the female connector on the tool end of the
hose may be connected to a pneumatic tool equipped with a male
connector in which the conductive portions 912, 914 are not wired
to anything, and thus are electrically isolated to define an open
circuit through which electricity will not flow even with the
switch 810 set to electric-tool-on. Alternatively, the male
connector on the tool may be made entirely of non-conductive
material to ensure the circuit is not closed. If the switch is set
to pneumatic-tool-on, the battery is connected to the pressure
switch 808 which will activate the motor 804 if the detected
pressure in the compressor manifold is below the predetermined
value, which will in turn run the compressor and feed compressed
air through the male/female coupling at the compressor, through the
air hose, through the male/female coupling at the tool end of the
hose, into the pneumatic tool for operation thereof.
[0300] It is also conceived that the system may be adapted to be
capable of providing both airflow and electricity to the tool end
of the electric/pneumatic power delivery hose, for example for use
with a hammer drill adapted to use electrical power for rotation
and pneumatic power for pounding. As with the portable compressor
assembly embodiments, the system may include a battery charger
which may also function as an adapter for use of an external power
source when desirable.
[0301] Since various modifications can be made in my invention as
herein above described, and many apparently widely different
embodiments of same made within the spirit and scope of the claims
without department from such spirit and scope, it is intended that
all matter contained in the accompanying specification shall be
interpreted as illustrative only and not in a limiting sense.
* * * * *