U.S. patent number RE42,706 [Application Number 12/798,490] was granted by the patent office on 2011-09-20 for airless spray pump.
This patent grant is currently assigned to Graco Minnesota Inc.. Invention is credited to Glen W. Davidson, Alexander L. Kapelevich.
United States Patent |
RE42,706 |
Davidson , et al. |
September 20, 2011 |
Airless spray pump
Abstract
An airless spray pump is provided with a single-acting piston
pump which allows the use of a low-cost yoke drive. Motor and pump
shaft are offset for most efficient force utilization.
Inventors: |
Davidson; Glen W. (Roseville,
MN), Kapelevich; Alexander L. (Shoreview, MN) |
Assignee: |
Graco Minnesota Inc.
(Minneapolis, MN)
|
Family
ID: |
26848977 |
Appl.
No.: |
12/798,490 |
Filed: |
August 28, 2000 |
PCT
Filed: |
August 28, 2000 |
PCT No.: |
PCT/US00/23613 |
371(c)(1),(2),(4) Date: |
February 27, 2002 |
PCT
Pub. No.: |
WO01/16462 |
PCT
Pub. Date: |
March 08, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60166946 |
Nov 22, 1999 |
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60151794 |
Aug 31, 1999 |
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Reissue of: |
10070117 |
Feb 27, 2002 |
6752067 |
Jun 22, 2004 |
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Current U.S.
Class: |
92/140;
417/415 |
Current CPC
Class: |
F04B
53/168 (20130101); F04B 9/02 (20130101); F04B
9/045 (20130101); F04B 17/03 (20130101) |
Current International
Class: |
F01B
9/00 (20060101); F04B 9/04 (20060101) |
Field of
Search: |
;92/140 ;417/415
;74/50 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lazo; Thomas E
Attorney, Agent or Firm: Kinney & Lange, P.A.
Claims
What is claimed is:
1. A spray pump powered by a rotary motor having a pinion thereon
and comprising: a housing; a single-acting piston pump having a
pump rod and connected to said housing; a drive gear assembly
comprising a gear .Iadd.rotatable about a gear centerline,
.Iaddend.and an eccentric located on said gear; a bearing located
about said eccentric; and a yoke reciprocatingly located in said
housing and about said bearing; wherein said .Iadd.gear centerline,
.Iaddend.motor and pinion are offset from .[.the.]. .Iadd.a
.Iaddend.centerline of said pump to reduce .[.the.]. thrust loads
on the yoke and offset and reduce .[.the.]. pump forces.
2. The spray pump of claim 1 wherein .[.the.]. teeth on said gear
are formed with about a 5.degree. helical angle and about a
25.degree. pressure angle.
3. The spray pump of claim 1 wherein said .[.motor and.]. pinion
.[.are offset from the centerline of said pump to reduce the thrust
loads on the yoke and offset and reduce the pump forces.]. .Iadd.is
driven by said motor and engages teeth of said gear to rotate said
gear and said eccentric about the gear centerline.Iaddend..
4. An airless spray pump having an inlet tube and an inlet filter
screen, the improvement comprising said inlet tube being provided
with a female threaded end and said inlet filter screen assembly
being provided with a male threaded end threaded engagement with
female end, said ends having the same size and thread as a common
garden hose such that a user need merely remove said screen
assembly and attach a garden hose to said inlet tube to flush out
the assembly.
.Iadd.5. The spray pump of claim 1, wherein the single-acting
piston pump pumps on a downward stroke of the pump rod and loads on
an upward stroke of the pump rod..Iaddend.
.Iadd.6. The spray pump of claim 5, wherein the pump rod is aligned
with the centerline of the pump..Iaddend.
.Iadd.7. The spray pump of claim 6, wherein the pump rod, yoke, and
bearing are located in a common plane..Iaddend.
.Iadd.8. The spray pump of claim 1, wherein the eccentric is
integral with a front of the gear assembly..Iaddend.
.Iadd.9. The spray pump of claim 1 and further comprising a motor
mounted to a rear portion of the housing..Iaddend.
.Iadd.10. The spray pump of claim 9, wherein the pinion is driven
by the motor..Iaddend.
.Iadd.11. A spray pump comprising: a rotary motor; a pinion driven
by the rotary motor; a housing; a single-acting piston pump having
a pump rod and connected to said housing wherein the single-acting
piston pump pumps on a downward stroke of the pump rod and loads on
an upward stroke of the pump rod, and wherein the pump rod is
aligned with a centerline of the piston pump; a drive gear assembly
comprising a gear driven by the pinion about a gear centerline, and
an eccentric located on said gear; a bearing located about said
eccentric; and a yoke reciprocatingly located in said housing and
about said bearing so that rotation of the gear and the eccentric
produce reciprocal motion of the yoke; wherein said gear
centerline, motor and pinion are offset from the centerline of said
pump to reduce the thrust loads on the yoke and offset and reduce
the pump forces..Iaddend.
.Iadd.12. The spray pump of claim 11, wherein the pump rod, yoke,
and bearing are located in a common plane..Iaddend.
.Iadd.13. The spray pump of claim 11, wherein the pump rod, yoke,
eccentric, and bearing are located in a common plane..Iaddend.
.Iadd.14. The spray pump of claim 11, wherein the eccentric is
integral with a front of the gear assembly..Iaddend.
.Iadd.15. The spray pump of claim 11 wherein the motor is mounted
to a rear portion of the housing..Iaddend.
.Iadd.16. The spray pump of claim 11, wherein the pinion includes
teeth that engate teeth on an outer circumferential surface of the
gear..Iaddend.
.Iadd.17. The spray pump of claim 11, wherein said teeth on said
gear and said pinion are formed with about a 5.degree. helical
angle and about a 25.degree. pressure angle..Iaddend.
Description
This application claims benefit of Provisional Applications No.
60/151,794 filed Aug. 31, 1999 and No. 60/166,946 filed Nov. 22,
1999.
TECHNICAL FIELD
Airless spray pumps for the spraying of paints and other
coatings.
BACKGROUND ART
Airless spray pumps for the spraying of paints and other coatings
via the airless method are well known and have traditionally been
divided into two types, diaphragm pumps for the lower end of the
market and reciprocating piston pumps for the higher end.
DISCLOSURE OF THE INVENTION
An airless spray pump is provided with a single-acting piston pump
which allows the use of a low-cost yoke drive. Motor and pump shaft
are offset for most efficient force utilization. The main drive
housing has a motor mounted to the rear thereof A gear assembly
uses gear teeth which are formed with a 5.degree. helical angle and
have a 25.degree. pressure angle. This geometry combines the higher
efficiency of straight cut gears with the noise reduction typified
in a helical design.
An eccentric is molded onto the front of the gear assembly and has
located thereabout a bearing assembly which rides inside a yoke.
The yoke moves vertically on guide rods which are retained in
pockets of the drive housing. The yoke is molded of plastic as is
the gear assembly leading to lower cost and easier manufacture.
The pump rod is provided with a cap over the top end thereof which
has bearing. Pump assembly is designed as a single acting pump,
that is, the pump only pumps on the downward stroke and loads on
the upward stroke. This allows the components of the drive train,
including the yoke and gear, to be much lighter as the yoke ends up
being more of a guidance device rather than a force-applying
device.
The motor and pinion are offset from the centerline of the pump
assembly. This arrangement does not have any significant
cantilevering as the pump rod, pinion, yoke, eccentric and cap are
all located in the same plane. The location of the rod and the
single acting pump with respect to the gear centerline reduces the
thrust loads on the yoke. The location of the pinion on the gear
partially offsets and reduces the pump forces on the gear shaft and
bearings. By locating the eccentric bearing directly on the end of
the pump rod cap which is press-fit it eliminates the transfer of
pumping force through an intermediate member such as the yoke which
provides longer life, efficiency and allows the manufacture of a
more inexpensive yoke assembly.
The shaft packing assembly is comprised of a packing housing which
screws into the pump housing and which contains a felt member which
has been soaked with throat seal lubricant or other solvent or
lubricant. A stack of v-packings are compressed in place by wave
spring which is tightened by tightening the seal housing into the
pump housing. The inlet check is provided with a check ball and a
check seat which is pressed into a check housing and which is held
in place by a retainer. These parts all press-fit into one another
such that the complete assembly be merely screwed into main pump
housing for replacement. Similarly, outlet check assembly is formed
of an outlet check housing which is screwed into a pump housing and
similarly is provided with a check ball held in place by a
retainer. The outlet passageway is angled relative to the axis of
the pump shaft. This allows the outlet check assembly to operate
essentially via gravity and yet requires only the drilling and
provision of one passageway while maintaining an essentially
vertical ball-seat relationship.
These and other objects and advantages of the invention will appear
more fully from the following description made in conjunction with
the accompanying drawings wherein like reference characters refer
to the same or similar parts throughout the several views.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a prospective exploded view showing the airless spray
pump with the instant invention.
FIG. 2 is a simple front plan view of the drive assembly and pump
of the instant invention.
FIG. 3 is a side plan view of the assembly shown in FIG. 1.
FIG. 4 is a detailed exploded view of the circled area in FIG.
3.
FIG. 5 is a cross-sectional view of the pump of the instant
invention.
FIG. 6 shows more details of the drive assembly of the instant
invention.
FIG. 7 is another cross-sectional view of the pump portion of the
instant invention.
FIG. 8 is a cross-section of the outlet filter of the instant
invention.
FIG. 9 is an exploded view of the outlet filter of the instant
invention.
FIG. 10 is a perspective exploded view of the instant
invention.
BEST MODE FOR CARRYING OUT THE INVENTION
The instant invention generally designated 10 is comprised of a
main drive housing 12 having a motor 14 mounted to the rear
thereof. A gear assembly 16 having a rear bearing 17 and gear teeth
22 is inserted into the bearing housing 20 of drive housing 12
.Iadd.to define gear centerline 41.Iaddend.. Gear teeth 22 on gear
assembly 16 mate with the teeth on pinion 24 on the end of motor
14. The teeth 22 and on pinion 24 are formed with a 5.degree.
helical angle and have a 25.degree. pressure angle. This geometry
combines the higher efficiency of straight cut gears with the noise
reduction typified in a helical design.
An eccentric 25 is also molded onto the front of gear assembly 16
and has located thereabout a bearing assembly 28 which rides inside
a yoke 30. Yoke 30 moves vertically on guide rods 32 which are
retained in pockets 34 of drive housing 12. Yoke 30 is molded of
plastic. Gear assembly 16 is cast in ZA-12 with an integral
counterweight leading to lower cost and easier manufacture.
Pump rod 36 is provided with a cap 38 over the top end thereof
which has bearing upon it bearing 28. Pump assembly 40 is designed
as a single acting pump that is the pump only pumps on the downward
stroke and loads on the upward stroke. In doing so this allows the
components of the drive train, including the yoke and gear, to be
much lighter as the yoke 30 ends up being more of a guidance device
rather than a force-applying device.
As can be seen more particularly in FIG. 2, motor and pinion 24 are
offset from the centerline 42 of pump assembly 40 which also has
offset therefrom bearing .[.20.]. .Iadd.28 .Iaddend.in the opposite
direction. Also, this arrangement does not have any significant
cantilevering as the pump rod, pinion, yoke, eccentric and cap are
all located in the same plane. The location of the rod and the
single acting pump with respect to the gear centerline .Iadd.41
.Iaddend.reduces the thrust loads on the yoke. The location of the
pinion on the gear partially offsets and reduces the pump forces on
the gear shaft and bearings. By locating the eccentric bearing
directly on the end of the pump rod cap which is press-fit it
eliminates the transfer of pumping force through an intermediate
member such as the yoke which provides longer life, efficiency and
allows the manufacture of a more inexpensive yoke assembly.
The shaft packing assembly 44 shown in FIG. 4 is comprised of a
packing housing 46 which screws into pump housing 48 and which
contains a felt member 50 which has been soaked with throat seal
lubricant or other solvent or lubricant. A stack of v-packings 52
are compressed in place by wave spring 54 which is tightened by
tightening seal housing 46 into pump housing 48.
Turning to FIG. 7, inlet check 56 is provided with a check ball 58,
a check seat 60 which is pressed into check housing 62 and which is
held in place by retainer and integral ball guide 64. These parts
all press-fit into one another such that the complete assembly be
merely screwed into main pump housing 48 for replacement.
Similarly, outlet check assembly .Iadd.57 .Iaddend.is formed of an
outlet check housing 60 which is screwed into pump housing 48 and
similarly is provided with a check ball 62 held in place by ball
seat 65. As can also be seen in FIG. 7, the outlet passageway 66 is
angled relative to the axis of pump shaft 36. This allows the
outlet check assembly .[.58.]. .Iadd.57 .Iaddend.to operate
essentially via gravity and yet requires only the drilling and
provision of one passageway while maintaining an essentially
vertical ball-seat relationship.
FIGS. 8 and 9 show the outlet filter assembly 80 which is comprised
of a filter element 82 contained in passage 84 of pump assembly 40
and which is retained by fitting 86.
Turning to FIG. 10, inlet tube 70 is provided with a female
threaded end 70a. Inlet filter screen assembly 72 has a male
threaded end 72a for threaded engagement with end 70a. Ends 70a and
72a use the same size and thread as a common garden hose such that
a user need merely remove screen assembly 72, attach a garden hose
to inlet tube 70, turn on the water and flush out the assembly.
It is contemplated that various changes and modifications may be
made to the airless spray pump without departing from the spirit
and scope of the invention as defined by the following claims.
* * * * *