U.S. patent application number 10/112665 was filed with the patent office on 2003-10-02 for pneumatic motor.
Invention is credited to Hartlaub, Charles, Rehkemper, Jeffrey.
Application Number | 20030183071 10/112665 |
Document ID | / |
Family ID | 28453402 |
Filed Date | 2003-10-02 |
United States Patent
Application |
20030183071 |
Kind Code |
A1 |
Rehkemper, Jeffrey ; et
al. |
October 2, 2003 |
PNEUMATIC MOTOR
Abstract
In one embodiment a pneumatic motor is provided that includes an
intake chamber in fluid communication with at least one intake
channel. Each intake channel is further in fluid communication with
a corresponding cylinder, which receives a piston that cycles
upwardly and downwardly to rotate a motor axle. A member is placed
in each intake channel to seal the corresponding cylinder from each
intake channel when compressed fluid in the intake channel has a
higher pressure then pressure in the corresponding cylinder. Each
piston includes an actuator extending downwardly from the piston
and having a profile that, during a portion of the upward cycle of
the piston, causes the actuator to push the member back into each
intake channel to allow compressed fluid into each of the
corresponding cylinders. Each piston includes a section that has a
diameter that creates a seal against the corresponding cylinder
during the upward cycle of the piston. Compressed fluid that enters
the corresponding cylinder during the upward cycle will push the
piston upwardly. Each section further includes exhaust grooves
defined thereon such during the downward cycle of the piston the
seal is broken allowing compressed fluid in the cylinder to bypass
the piston and escape through a vent above each cylinder. This
causes the compressed fluid in the intake channel to push the
member to re-seal the cylinder. The upward movement of the piston
further generates inertia that moves the piston downward to
continue the cycle.
Inventors: |
Rehkemper, Jeffrey;
(Chicago, IL) ; Hartlaub, Charles; (Glendale
Heights, IL) |
Correspondence
Address: |
JACK SHORE
MUCH SHELIST FREED DENENBERG AMENT&RUBENSTEIN,PC
191 N. WACKER DRIVE
SUITE 1800
CHICAGO
IL
60606-1615
US
|
Family ID: |
28453402 |
Appl. No.: |
10/112665 |
Filed: |
March 28, 2002 |
Current U.S.
Class: |
91/325 |
Current CPC
Class: |
F16J 1/12 20130101; F01L
21/00 20130101; F01L 23/00 20130101; F01B 17/02 20130101; F01B
9/026 20130101 |
Class at
Publication: |
91/325 |
International
Class: |
F01L 021/02 |
Claims
1. A pneumatic motor for rotating an axle comprising: a piston
attached to the axle, wherein when the piston moves upwardly or
downwardly, the axle rotates therewith; a housing defining at least
an intake chamber to receive a compressed fluid, an intake channel
in fluid communication with the intake chamber, and a cylinder in
fluid communication with the intake channel and sized to receive
the upwardly and downwardly moving piston, the housing further
defining an exhaust positioned above the cylinder and in fluid
communication with the cylinder; a member positioned in the intake
channel to seal the cylinder from the intake channel, when the
cylinder contains a pressure less then the compressed fluid in the
intake channel; an actuator extending downwardly from the piston
and having a profile defined such that, during a predetermined
portion of the upwardly movement of the piston, the actuator exerts
a force against the member sufficient to push the member into the
intake channel allowing compressed fluid in the intake channel to
enter the cylinder; and a section defined by the piston and having
a diameter to create a temporary seal against the cylinder such
that compressed fluid that enters the cylinder via the intake
channel will exert a force against the section pushing the cylinder
upwardly, the section further includes exhaust grooves formed
therein and positioned such that said temporary seal is created
only during upward movement of the piston and said seal is broken
during downward movement of the piston, wherein when the seal is
broken compressed fluid in the cylinder below the section may vent
upwardly past the section and out through the exhaust, which causes
the pressure in the cylinder to become lower then the pressure of
the compressed fluid in the intake channel and ensures that the
member re-seals the cylinder from the intake channel.
2. The motor of claim 1, wherein inertia caused by the upward
stroke of the piston acting on the crank causes the piston to move
downwardly and at least begin again the upward stroke to a position
that causes the actuator to contact and push the member into the
intake channel to allow compressed fluid into the cylinder.
3. The motor of claim 2, wherein the actuator is integrally formed
to the piston.
4. The motor of claim 3, wherein the intake chamber includes an
external port in fluid communication with an external tank, the
external tank having the compressed fluid contained therein.
5. The motor of claim 3, wherein the intake chamber includes an
external port in fluid communication with a pump system, the pump
system having the ability to supply compressed fluid to the
pneumatic motor.
6. The motor of claim 1, wherein the intake chamber includes a
protrusion in front of the intake channel to prevent the member
from entering the intake chamber.
7. The motor of claim 1, wherein the profile of each actuator is
defined by a motion of the piston, a profile defined by the member,
and time needed to allow a sufficient amount of compressed fluid
into each cylinder, such that the actuator will exert a sufficient
and continued amount of pressure on the member to push the member
into the intake channel allowing the sufficient amount of
compressed fluid into the cylinder to force the piston
upwardly.
8. A pneumatic motor for rotating an axle comprising: a housing
defining at least two cylinders, each cylinder sized to receive a
corresponding piston, each cylinder is in fluid communication with
a corresponding intake channel in the housing that is in fluid
communication with an intake chamber defined by the housing, each
cylinder further having a corresponding exhaust; a crank attached
to the axle and the pistons, wherein when the pistons move upwardly
or downwardly, the axle rotates therewith; a member positioned in
each intake channel that seals the corresponding cylinder from the
intake channel when compressed fluid initially enters the intake
channel; an actuator extending downwardly from each piston and
having a profile defined such that the actuator may exert a force
against the member sufficient to push the member into the intake
channel allowing compressed fluid in the intake channel to enter
the corresponding cylinder; and a section defined on each piston
and having a diameter larger then the actuator that creates a fluid
seal against the corresponding cylinder such that compressed fluid
entering the corresponding cylinder via the intake channel will
exert a force against the section pushing the cylinder upwardly,
the section further includes exhaust grooves formed therein and
positioned such that said fluid seal is created only during upward
movement of the piston and said fluid seal is broken during
downward movement of the piston, wherein when the fluid seal is
broken compressed fluid in the cylinder below the section may
escape upwardly past the section and out through the corresponding
exhaust, which causes the compressed fluid in the intake channel to
push the member to ensure that the member re-seals the cylinder
from the intake channel.
9. The motor of claim 8, wherein inertia caused by the upward
stroke of the piston acting on the crank causes the piston to move
downwardly and at least begin again the upward stroke to a position
that causes the actuator to contact and push the member into the
intake channel to allow compressed fluid into the cylinder.
10. The motor of claim 8, wherein the profile of each actuator is
defined by a motion of the piston, a profile defined by the member,
and time needed to allow a sufficient amount of compressed fluid
into each cylinder, such that the actuator will exert a sufficient
and continued amount of pressure on the member to push the member
into the intake channel allowing the sufficient amount of
compressed fluid into the cylinder to force the piston
upwardly.
11. The motor of claim 8, wherein the section is integrally formed
from the piston.
12. The motor of claim 11, wherein the intake chamber includes a
protrusion in front of each intake channel to prevent the members
from entering the intake chamber.
13. The motor of claim 8, wherein the actuator is integrally formed
to the piston.
14. The motor of claim 8, wherein the pistons are offset from each
other.
15. A pneumatic motor comprising an intake chamber in fluid
communication with at least one intake channel, each intake channel
is further in fluid communication with a corresponding cylinder,
each cylinder receiving a piston that cycles upwardly and
downwardly to rotate a motor axle, a valve member in each intake
channel will seal the corresponding cylinder from each intake
channel when compressed fluid in the intake channel has a higher
pressure then pressure in the corresponding cylinder, each piston
further includes an actuator extending downwardly from the piston
and having a profile that, during a portion of the upward cycle of
the piston, causes the actuator to push the member back into each
intake channel to allow compressed fluid to enter each of the
corresponding cylinders, each piston further includes a section
that has a diameter that creates a fluid seal against the
corresponding cylinder during the upward cycle of the piston such
that compressed fluid that enters the corresponding cylinder during
the upward cycle will push the piston upwardly, each section
further includes at least one exhaust vent defined thereon such
during the downward cycle of the piston the fluid seal is broken
allowing compressed fluid in the cylinder to bypass the mid-section
piston and escape through an exhaust above each cylinder, which
causes the compressed fluid in the intake channel to push the
member to re-seal the cylinder from the intake channel, the upward
movement of the piston further generates inertia that moves each
piston downward to a position that causes the actuator on each
piston to contact and push the corresponding member into the intake
channel defining a complete cycle, wherein said complete cycle will
continue as long as compressed fluid is supplied to the intake
chamber.
16. The motor of claim 15, wherein the profile of each actuator is
defined by a motion of the piston, a profile defined by the member,
and time needed to allow a sufficient amount of compressed fluid
into each cylinder, such that the actuator will exert a sufficient
and continued amount of pressure on the member to push the member
into the intake channel allowing the sufficient amount of
compressed fluid into the cylinder to force the piston
upwardly.
17. The motor of claim 15, wherein the section is integrally formed
from the piston.
18. The motor of claim 15, wherein the intake chamber includes a
protrusion in front of each intake channel to prevent the members
from entering the intake chamber.
19. The motor of claim 15, wherein the intake chamber includes an
external port in fluid communication with an external tank, the
external tank having the compressed fluid contained therein.
20. The motor of claim 15, wherein the intake chamber includes an
external port in fluid communication with a pump system, the pump
system having the ability to supply compressed fluid to the
pneumatic motor.
21. A pneumatic motor comprising at least one piston, each sized to
be received in a corresponding cylinder, each piston is further
defined by having a section that has diameter that creates a fluid
seal against the corresponding cylinder during an upward stroke of
the piston, each section further includes exhaust vents positioned
to temporarily open the fluid seal during a downward stroke of the
piston, a connecting rod extending upwardly from the section to
engage a crank shaft, and an actuator extending downwardly from the
section and having a means to allow compressed fluid into the
cylinder.
22. The motor of claim 21 wherein the section, connecting rod and
the actuator is a single rigid piece.
23. The motor of claim 21 wherein the means to allow compressed
fluid into each cylinder is further defined as: each cylinder being
in fluid communication with a corresponding intake channel, each
intake channel having a member sized to create a fluid seal between
the cylinder and the corresponding intake channel when the cylinder
contains a pressure less then the compressed fluid in the intake
channel, and each actuator having a profile defined to push the
member into the intake channel to brake the fluid seal and allow
compressed fluid contained in the intake channel to enter into the
corresponding cylinder, during a portion of the upward stroke of
the piston.
24. The motor of claim 23, wherein the exhaust vents are defined
such that the fluid seal between the piston and the cylinder is
broken during the entire downward stroke of the piston such that
compressed fluid in the cylinder is permitted to vent during the
entire downward stroke of the piston.
25. The motor of claim 24, wherein each piston generates inertia in
the crank shaft during the upward stroke of the piston such that
the inertia continues to move each piston through the downward
stoke to a position in the upward stroke that causes the actuator
on each piston to push the corresponding member into the intake
channel allowing compressed fluid back into the cylinder.
26. The motor of claim 25, wherein each piston will continue to
move upwardly and downwardly as long as compressed fluid is
supplied to the intake channel.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to pneumatic operated motors,
and in particular to a motor that uses compressed fluid or air to
power the motor. A pneumatic motor may be used in a wide variety of
applications, from wheeled vehicles to propeller operated airplanes
and helicopters, as well as air powered boats. In addition, other
applications in various other fields of use are just now being
realized, such as any air powered or battery powered product.
[0002] One problem in the prior art, which is realized and solved
by the present invention, is simplicity. The ability to provide an
efficient pneumatic motor without the need of complicated intake
and exhaust ports, spring operated pistons, valve rods, piston
connection rods, individual seals, specially designed seal skirts,
complicated drive axle mountings, etc. All of which complicates the
manufacturing of the pneumatic motor and increases the likelihood
that an individual part will break making the motor inoperable. As
such a need exists to improve upon the prior art pneumatic motors.
Such an improvement should simplify the manufacturing by
eliminating the need for complicated mechanisms, additional rods,
seals, springs and etc. such an improvement will further provide
for pneumatic motors that may be made smaller, lighter and less
expensive than other prior art motors.
[0003] For example, U.S. Pat. No. 4,329,806 to Akiyama discloses a
fluid engine for use in pneumatic operated toys. The '806 patent
uses a complicated structure that includes a intake valve rod that
is connected to a disc element that is also connected to a parallel
drive axle. A piston, perpendicular to the drive axle and the valve
rod, is in communication with the disc element that is rotated by
the upward and downward movement of the piston. The disc element
also includes a profile surface in contact with the valve rod. When
the disc element rotates, the profile surface causes the valve rod
to move inwardly, when the piston is moving upwardly, and to move
outward, when the piston is moving downwardly. In addition, when
the valve rod moves inwardly, fluid or compressed air enters the
chamber. The air pushes the piston upwards and eventually expels
out of a side exhaust. The inertia in the drive axle caused of the
upward movement of the piston will continue to move the piston
downwards such that the process will continue, until the air runs
out.
[0004] U.S. Pat. No. 6,006,517 to Kowanacki utilizes a compressed
spring to close an intake valve, where air enters into the cylinder
or chamber. A valve member is pushed upwardly by the compressed
spring against an aperture creating a air tight seal. A piston
moving downwards pushes the member down passed an intake valve,
allowing compressed air to flow over the member through the
aperture into a chamber. The air pushes the piston up causing a
drive axle attached thereto to rotate. Once the piston is moved up
the compressed spring pushes the member back up closing the intake
valve. Moreover, the air entering the chamber with the piston
escapes out of side exhaust ports (cut into the chamber) when the
piston reaches the top position. U.S. Pat. No. 6,085,631 utilizes
the same principles in the '517 patent except it introduces a
low/high pressure seal that expands when air is pressed up against
it.
[0005] In addition it is well known that when manufacturing, the
size of the product will be dependent upon all of the parts. If a
pneumatic motor is desired to be extremely small, say the size of
about an inch in length or less, it would be virtually and/or
practically impossible using the pneumatic motors of the prior art
to manufacture all of the parts small enough and assembly the same
to fit this size. A benefit realized by the pneumatic motor of the
present invention was found that the size could be made extremely
small because of the simplicity of the present invention.
[0006] However on the other extreme, because of the simplicity it
is also extremely easy to make the pneumatic motor larger. As such,
the present invention finds applicability in compressed
fluid-powered engines used for operating automobiles, such as
described by U.S. Pat. No. 6,006,519. The '519 patent discloses a
compressed air-powered engine designed for use in an internal
combustion engine, using a "Wankel-type rotary engine."
SUMMARY OF THE INVENTION
[0007] In accordance with the present invention a pneumatic motor
is provided. The pneumatic motor includes at least one piston, each
of which is attached to a crank shaft such that when the piston
moves upwardly and downwardly an axle attached to the crank shaft
rotates therewith. The pneumatic motor includes a housing having a
cylinder for each piston. Each cylinder is in fluid communication
with a corresponding intake channel in the housing that is also in
fluid communication with an intake chamber. Each cylinder further
has a corresponding exhaust through the top portion of the housing.
Each intake channel houses a member that seals the corresponding
cylinder from the intake channel when compressed fluid initially
enters the intake channel or when the pressure in the intake
channel is greater then the pressure in the cylinder.
[0008] Each piston is preferably defined by a single rigid piece
that has a connecting rod extending upwardly to attach to the crank
shaft, an actuator that extends downwardly to contact and push the
member, and has a section with a diameter that is defined to create
a temporary or artificial fluid seal against the corresponding
cylinder wall. As mentioned above, extending downwardly from each
piston is an actuator that has a profile or camber defined such
that the actuator may exert a force against the member sufficient
to push the member into the intake channel allowing compressed
fluid in the intake channel to enter the corresponding
cylinder.
[0009] The piston also includes a section that has a diameter that
is defined to create a temporary or artificial fluid seal against
the corresponding cylinder wall, such that compressed fluid
entering the corresponding cylinder via the intake channel cannot
initially escape. As such, the compressed fluid exerts a force
against the section pushing the cylinder upwardly. The section
further includes exhaust grooves formed therein and positioned such
that the fluid seal is created only during upward movement of the
piston and the fluid seal is broken during downward movement of the
piston. This is caused because during the upward and downward
movement of the piston, the connecting rod is a rigid extension of
the piston that connects to a rotating crank shaft, such that the
piston also pivots within the cylinder. When the fluid seal is
temporarily broken, compressed fluid in the cylinder below the
section escapes upwardly past the section and out through the
exhaust. This also causes the compressed fluid in the intake
channel to push the member back against the cylinder ensuring that
the member re-seals the cylinder from the intake channel.
[0010] Inertia from the crank shaft, caused by the upward stroke of
the piston, continues to move the piston through the downward
stroke into a position in the upward stroke that causes the
actuator to contact and push the member inwardly allowing the
compressed fluid to reenter the cylinder. Thereby creating a cycle
that will continue as long as the supply of compressed fluid to the
intake channel(s) is maintained.
[0011] The present invention may be designed as small as
manufacturing allows as well as large as desired. The present
invention may therefore find applicability in full-scale air
compressed engines that may be used in vehicles, planes, boats,
helicopters, as well as miniature-scaled engines used to operate
toys and/or other consumer or industrial air powered or battery
powered products.
[0012] Numerous other advantages and features of the invention will
become readily apparent from the following detailed description of
the invention and the embodiments thereof, from the claims, and
from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A fuller understanding of the foregoing may be had by
reference to the accompanying drawings, wherein:
[0014] FIG. 1 is a perspective cross-sectional view of a single
piston pneumatic motor in accordance with one embodiment of the
present invention;
[0015] FIG. 2 is a cross-sectional view of the pneumatic motor from
FIG. 1;
[0016] FIGS. 3a-3i are cross-sectional views of the pneumatic motor
from FIG. 1, illustrating the piston through various stages of a
single cycle;
[0017] FIG. 4 is a cross-sectional view of the pneumatic motor from
FIG. 1, illustrating the piston during the down stroke with the
seal between the section and the cylinder walls open allowing
compressed fluid to vent;
[0018] FIG. 5 is a rear view of the piston and crank from FIG.
1;
[0019] FIG. 6 is a pneumatic motor with an external tank of
compressed fluid;
[0020] FIG. 7 is an exploded view of a three piston pneumatic motor
in accordance with another embodiment of the present invention;
and
[0021] FIG. 8 is a cross-sectional view of a piston in accordance
with the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] While the invention is susceptible to embodiments in many
different forms, there are shown in the drawings and will be
described herein, in detail, the preferred embodiments of the
present invention. It should be understood, however, that the
present disclosure is to be considered an exemplification of the
principles of the invention and is not intended to limit the spirit
or scope of the invention and/or claims of the embodiments
illustrated.
[0023] Referring now to FIGS. 1 and 2, a pneumatic motor 10 in
accordance with one embodiment of the present invention includes a
piston 12 attached to a crank shaft 14. The crank shaft 14 when
rotating drives a main axle 16 (shown in FIG. 5). The main axle 16
may then be attached, by various known means in the art, to any
means operable from a motor. Such motor operable means may include
wheels and propellers; however, the specific invention is not
necessarily limited to such commonly known motor operable means and
may also include the ability to produce electrical power from the
rotation of the main axle 16, or may be attached to any compressed
fluid or compressed air powered product.
[0024] Continuing to refer to FIGS. 1 and 2, the motor 10 is
defined by a main housing 18, an intake housing 26 and a top motor
housing 50. The main housing 18 includes a cylinder 20 integrally
molded or bored therethrough. The pneumatic motor 10 is powered by
compressed fluid, preferably air, that enters into an intake
chamber 22 from an external line 24. The intake chamber 22 is
formed inside of the intake housing 26, which is secured to the
main housing 18.
[0025] From the intake chamber 22, the compressed fluid enters into
an intake channel 28 that is grooved into the main housing 18. A
member 30, having a diameter less than the diameter of the intake
channel 28 is contained therein. The intake channel 28 also
includes an intake aperture 32 leading into the cylinder 20
permitting the intake channel 28 to be in fluid communication with
the cylinder 20. To keep the member 30 in the intake channel 28, a
portion of the entrance of the intake chamber 22 is covered by a
protrusion 27 formed out of the intake housing 26. The diameter of
the intake aperture 32 is also smaller then the diameter of the
member 30, such that the member 30 may extend partly into the
cylinder 20 but will not entirely enter into the cylinder 20.
[0026] When the cylinder 20 is empty or when it contains fluid that
has a pressure less then the pressure of compressed fluid in the
intake channel 28, the compressed fluid will act on the member 30
pushing it against the intake aperture 32 creating a fluid tight
seal. As such the compressed fluid is prevented from entering the
cylinder 20. As discussed in greater detail below, to allow
compressed fluid to enter into the cylinder 20, the member 30 is
forced or pushed back into the intake channel 28 toward the
protrusion 27 by an actuator 34 integrally formed into the lower
portion of the piston 12. Once the member 30 is pushed into the
intake channel 28, compressed fluid will flow around the member 30
and enter the cylinder 20 through the intake aperture 32.
[0027] Continuing to Refer to FIG. 2, the piston 12 and the
movement of the piston will now be described in detail. As opposed
to other prior art pneumatic motors, the present invention
preferably includes a piston 12 that incorporates therein a
connecting rod 13, a section 36, an actuator 34 (or a means to
allow compressed fluid into the cylinder 20) and exhaust grooves 38
as a single integrally molded piece. However, the present invention
may also include a rigid piston that includes as separate parts the
connecting rod, the section and the actuator attached thereto.
[0028] In other prior art piston motors, the piston and connecting
rod are separate. Attached to each other by various gears allowing
the piston to move vertically and the connecting rod to transfer
the rotation motion of the crank shaft to the piston. However, the
present invention incorporates the connecting rod 13 into the
piston 12, this causes the piston to move vertically as well as
pivotally. As thus permits the piston 12, of the present invention,
to perform like a rocker arm or cam utilized in most prior art
patents. In addition, the other functions and characteristics in
this invention, defined by the movement of the piston 12, are also
possible.
[0029] Referring still to FIG. 2, the connection rod 13 includes a
top portion 40 that clips onto the crank shaft 14. Other attachment
means may also be used; for example, the top portion 40 could
simply include an aperture that permits the crank shaft 14 to slide
therethrough. The crank shaft 14 is further attached to a crank 15,
which is attached to the main axle (not shown).
[0030] From the position shown in FIG. 2, as soon as the piston 12
moves upward, illustrated in FIG. 3a, the actuator 34 begins to
push against the member 30, forcing the member 30 into the intake
channel 28. At this point compressed fluid enters the cylinder 20
and pushes against the section 36 forcing the piston upwards, FIGS.
3a-3d. It is important to note, that the section 36 has a diameter
that creates a temporary fluid seal against the cylinder walls 42,
during the upward stroke of the piston 12. At some point prior to
top dead center, shown in FIG. 3e, the actuator 34 on the piston 12
disengages the member 30, but the compressed fluid will continue to
push against the section 36, because of the fluid seal.
[0031] Another important aspect to note is that the profile 44 of
the actuator 34 is defined such that the actuator 34 is in
continual engagement with the member 30 during a predetermined part
of the cycle. As illustrated in FIGS. 3a-3i, when the piston 12 is
moving through a single rotation, the piston 12 also pivots. The
profile 44 of the actuator 34 is therefore a function of the
pivoting of the piston 12 and the profile of the member 30, such
that the actuator 34 exerts a sufficient and continued amount of
pressure on the member 30 to force or push the member 30 into the
intake channel 28. In addition the profile 44 of the actuator 34 is
also a function on the amount of compressed fluid needed to enter
the cylinder 20 and force the piston 12 upwards. If the cylinder 20
is larger, more compressed fluid may be needed in the cylinder 20
to properly force the piston 12 through the upward stroke, as such
the profile 44 may need to be extended to keep pressure on the
member 30 longer.
[0032] As mentioned above, throughout this upward movement of the
piston 12, a fluid seal is created between the section 36 and the
cylinder wall 42 and maintained preventing the compressed fluid
from exiting the cylinder 20. The inertia of crank shaft 14 will
continue to move the piston 12 past the top dead center position,
illustrated in FIG. 3f. Once it is through top-dead center,
illustrated in FIGS. 3g-3h, the piston 12 begins to pivot in the
opposite direction as shown in FIGS. 3a-3d. The pivot during the
downward stroke breaks the fluid seal between the section 36 and
the cylinder wall 42, because exhaust grooves 38 (one of which is
better illustrated in FIG. 5) formed into the section 36 create
temporary passages 46 between the section 36 and the cylinder wall
42, also shown in FIG. 4. The compressed fluid is now able to
escape and will continue to escape out of the cylinder 20 until the
pneumatic seal between the section 36 and the cylinder wall 42 is
re-created. Preferably the fluid seal is broken at a position
before top-dead center, FIG. 3f, and created at a position after
bottom-dead center, FIG. 3i. However, altering the depth of the
exhaust groove 38 may change these positions.
[0033] As opposed to other prior art piston motors, the present
invention's temporary fluid seal between the piston 12 and the
cylinder wall 42 is unique in that the seals utilized in other
prior art motors are engaged during the upward and downward stroke
of the piston. Typically, the prior art motors never break the
seal. The compressed fluid is allowed to exhaust usually through a
side exhaust channel that is open when the piston reaches top dead
center. As soon as the prior art pistons begin the downward stroke,
the seal is re-created. This causes a loss in performance, because
the piston will utilize inertia re-compressing any fluid trapped
under the seal during the downward stroke and fighting the
re-compressed fluid, in order to return to a position that allows
more compressed fluid into the cylinder. However, since the present
invention maintains the open passages 46 during the downward
stroke, there will be virtually no loss or recompression of any
fluid during the downward stroke.
[0034] When the fluid seal is broken, the compressed fluid escapes
the motor 10 through an exhaust 48 in a top motor housing 50. In
addition, once the fluid seal is broken there is a pressure
difference between the compressed fluid entering the cylinder 20
and the compressed fluid exiting the cylinder 20, ensuring the
member 30 seals against the intake aperture 32. As mentioned above
the inertia of the crank is sufficient enough to move the piston 12
downwardly to a point in which the actuator 34 begins to push the
member 30 inwardly, causing the cycle explained above to
repeat.
[0035] Once this cycle is started, the pneumatic motor 10 will
continue to run until the supply of compressed fluid is expended.
To begin the cycle, the main axle 16 may be initially moved,
causing the crank 15 to move the piston 12 downwardly to a point
past bottom dead center in which the actuator 34 moves the member
30 inwardly. Alternatively, other mechanical or electrical means
may be employed to initiate the cycle.
[0036] The compressed fluid, in one embodiment, is provided from an
external tank 60 that is attached to the external line 24, shown in
FIG. 6. The external tank 60 may be a closed system, which would be
replaced after exhausted, or refillable. Both types of tank systems
are well known in the art. Alternatively the external line 24 may
feed directly into a pump system that continuously supplies
compressed fluid, also well known in the art.
[0037] In addition to the single piston pneumatic motor illustrated
herein, multiple piston motors are provided for in additional
embodiments. As illustrated in FIG. 7 a three piston 12 pneumatic
motor 10 is shown; however two piston pneumatic motors are also
embodied herein. The principles discussed herein above for the
single piston 12 motor are applicable with a multiple piston motor.
In addition, while the pistons are illustrated in series, the
pistons could further be provided for in an offset motor, such as
found in typically V-8 engines.
[0038] Referring now to FIG. 8, it should be further understood
that changing various dimensions of the piston 12 could alter the
performance of the pneumatic motor 10. For instance increasing the
exhaust grooves 38 would permit the compressed fluid to exhaust
longer. This may be required where the outside fluid is different
then the compressed fluid, or where the outside pressure warrants a
longer exhaust. The profile 44 may also be changed to control the
amount of compressed fluid that enters into the cylinder 20. The
length l.sub.a of the actuator 34 may be changed to alter the time
the cylinder is under pressure. The length l.sub.tp defined by the
distance between axis of the crank shaft 14 to the section 34
(length of the connecting rod 13) may be changed to change the
stroke length. This could be decreased to further compact the
motor. In addition the stroke length l.sub.s defined by the
distance from the drive axle 16 to the axis of the crank shaft 14
may be changed to affect the speed of the motor.
[0039] In accordance with the present invention, the pneumatic
motor disclosed herein may be designed as small as manufacturing
allows as well as large as desired. The present invention may
therefore find applicability in full-scale air compressed engines
that may be used in vehicles, planes, boats, helicopters, as well
as miniature-scaled engines used to operate toys or other small
motor operated devices without the need for batteries.
[0040] From the foregoing and as mentioned above, it will be
observed that numerous variations and modifications may be effected
without departing from the spirit and scope of the novel concept of
the invention. It is to be understood that no limitation with
respect to the specific methods and apparatus illustrated herein is
intended or should be inferred. It is, of course, intended to cover
by the appended claims all such modifications as fall within the
scope of the claims.
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