U.S. patent application number 10/839298 was filed with the patent office on 2005-11-10 for cam-driven pump mechanism for a battery-powered grease gun.
Invention is credited to Huang, San-I, Yeh, Hao-Jung.
Application Number | 20050249616 10/839298 |
Document ID | / |
Family ID | 35239605 |
Filed Date | 2005-11-10 |
United States Patent
Application |
20050249616 |
Kind Code |
A1 |
Huang, San-I ; et
al. |
November 10, 2005 |
Cam-driven pump mechanism for a battery-powered grease gun
Abstract
A cam-driven pump mechanism for a battery-powered grease gun
includes a cam driver and a cam-driven pump. The grease gun has a
transition body having a grease channel and a casing having an
inner chamber. The cam driver is mounted in the inner chamber. The
cam-driven pump has a cylindrical cam, a sliding block, a follower
and a piston. The cylindrical cam is rotatably mounted in the inner
chamber, is rotated by the cam driver and has an eccentric annular
groove. The sliding block is slidably mounted in the casing. The
follower is securely attached to the sliding block and mounted
slidably in the eccentric annular groove. The piston is mounted
slidably in the grease channel and connects to the sliding block.
Consequently, use of the cylindrical cam prevents localized
friction on the sliding block and keeps the pump mechanism from
wearing excessively.
Inventors: |
Huang, San-I; (Taichung,
TW) ; Yeh, Hao-Jung; (Taichung, TW) |
Correspondence
Address: |
HERSHKOVITZ & ASSOCIATES
1725 I STREET NW, SUITE 300
WASHINGTON
DC
20006
US
|
Family ID: |
35239605 |
Appl. No.: |
10/839298 |
Filed: |
May 6, 2004 |
Current U.S.
Class: |
417/415 ;
417/234; 417/411 |
Current CPC
Class: |
F04B 19/027
20130101 |
Class at
Publication: |
417/415 ;
417/234; 417/411 |
International
Class: |
F04B 017/00; F04B
035/04 |
Claims
What is claimed is:
1. A cam-driven pump mechanism for a battery-powered grease gun
having a body with a casing with an inner chamber and a discharge
assembly with a transition body having a grease channel aligned and
communicating with the inner chamber, and the cam-driven pump
mechanism comprising: a cam driver adapted to be mounted in the
inner chamber; and a cam-driven pump driven by the cam driver and
the cam-driven pump comprising a cylindrical cam adapted to be
rotatably mounted in the inner chamber, rotated by the cam driver
and having an outside surface and an eccentric annular groove
formed in the outside surface; a follower mounted slidably in and
driven by the eccentric annular groove in the cylindrical cam; a
sliding block adapted to be mounted slidably in the inner chamber,
attached securely to the follower and driven by the follower; and a
piston attached to the sliding block, adapted to be mounted
slidably in the grease channel and driven up and down in the grease
channel by the sliding block.
2. The cam-driven pump mechanism as claimed in claim 1, wherein the
cam driver comprises a planetary gear assembly comprises a gear
housing adapted to be mounted in the casing; and a set of planetary
gears mounted in the gear housing and connected to the cylindrical
cam; and a motor attached to the gear housing and connected to and
rotating the set of planetary gears to rotate the cylindrical
cam.
3. The cam-driven pump mechanism as claimed in claim 2, wherein the
cylindrical cam further has a rectangular drive shaft connected to
the set of planetary gears; the sliding block has a follower hole
in which the follower is securely attached and a piston slot; and
the piston has an annular groove engaging with the piston slot.
4. The cam-driven pump mechanism as claimed in claim 3, further
comprising a bushing mounted around the follower and mounted
slidably in the eccentric annular groove in the cylindrical cam.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a battery-powered grease
gun, and more particularly to a battery-powered grease gun that
uses a cylindrical cam to drive a pump mechanism to continuously
discharge grease from the grease gun.
[0003] 2. Description of Related Art
[0004] With reference to FIGS. 5 and 6, a conventional
battery-powered grease gun has a body (60) and a pump assembly (not
numbered). The pump assembly is mounted in the body (60) and
comprises a motor (64), a planetary gear assembly (65), a drive
disk (66), a drive pin (67), a sliding block (68), a piston (69)
and a transition body (61) with a drive channel (not numbered).
[0005] The body (60) has a grease channel (601), connects to a
cylindrical lubricant cartridge holder (602) and comprises a ball
check valve (62) and a discharge spout (63). The discharge spout
(63) communicates with the grease channel (601). The ball check
valve (62) is mounted between the grease channel (601) and the
discharge spout (63) to control flow rates of grease in the grease
channel (601) entering into the discharge spout (63).
[0006] The transition body (61) is attached to the body (60) with
the drive channel communicating with the grease channel (601). The
sliding block (68) is mounted slidably in the drive channel and has
a transverse slot (681) and an attachment slot (682). The planetary
gear assembly (65) reduces the speed and increases the torque of
the motor (64). The drive disk (66) is coupled to and rotated by
the planetary gear assembly (65) and has an eccentric threaded hole
(not numbered). The drive pin (67) has a threaded end (not
numbered) and a bottom end (not numbered). The threaded end is
screwed into the eccentric threaded hole in the drive disk (66),
and the bottom end extends into the transverse slot (681) in the
sliding block (68) to drive the sliding block (68) back and forth
in the drive channel. The piston (69) has a distal end (not
numbered) and a proximal end (not numbered). The distal end is
mounted slidably in the grease channel (601), and the proximal end
is attached to the attachment slot (682) in the sliding block (68).
The cylindrical lubricant cartridge holder (602) is attached to the
body (60) and communicates with the grease channel (601) to supply
lubricant to the grease channel (601).
[0007] To discharge the grease, the motor (64) rotates the drive
disk (66) through the planetary gear assembly (65). The rotating
drive disk (66) and drive pin (67) move the sliding block (68) back
and forth in the drive channel. The sliding block (68) moves the
piston (69) back and forth, which pumps the grease in the grease
channel (601) out through the discharge spout (63).
[0008] Since a single drive pin (67) drives the sliding block (68)
as the driving pin (67) slides in the transverse slot (681), the
drive pin (67) presses against half of each face of the transverse
slot (681) when pushing the sliding block (68) in one direction.
This action causes the transverse slot (681), the sliding block
(68) and the drive channel to wear unevenly. This uneven wear
eventually causes the pump mechanism to operate erratically and be
unreliable. Furthermore, the uneven wear makes replacement of the
sliding block (68) periodically necessary.
[0009] To overcome the shortcomings, the present invention provides
a cam-driven pump mechanism to mitigate or obviate the
aforementioned problems.
SUMMARY OF THE INVENTION
[0010] The main objective of the present invention is to provide a
cam-driven pump mechanism for a battery-powered grease gun, and the
cam-driven pump mechanism keeps any part of the pump mechanism from
wearing excessively to extend the life of the grease gun.
[0011] The cam-driven pump mechanism for a battery-powered grease
gun in accordance with the present invention includes a cam driver
and a cam-driven pump. The grease gun has a body with a discharge
assembly, a casing and a cartridge holder. The casing has an inner
chamber and, the discharge assembly has grease channel
communicating with the inner chamber.
[0012] The cam driver comprises a planetary gear assembly and a
motor mounted in the inner chamber.
[0013] The cam-driven pump comprises a cylindrical cam, a sliding
block, a follower and a piston. The cylindrical cam is mounted
rotatably in the inner chamber, is connected to and driven by the
cam driver and has an eccentric annular groove. The sliding block
is mounted slidably in the inner chamber and is aligned with the
grease channel. The follower is attached securely to the sliding
block and mounted slidably in the eccentric groove in the
cylindrical cam, which causes the sliding block to reciprocate when
the cylindrical cam rotates. The piston is slidably mounted in the
grease channel and connected to the sliding block to slide
reciprocally in the grease channel to pump grease continuously out
of the grease gun.
[0014] Consequently, use of the cylindrical cam prevents localized
friction on the sliding block and keeps the parts of the pump
mechanism from wearing excessively.
[0015] Other objectives, advantages and novel features of the
invention will become more apparent from the following detailed
description when taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a perspective view of a battery-powered grease gun
in accordance with the present invention;
[0017] FIG. 2 is an exploded perspective view of the
battery-powered grease gun in FIG. 1;
[0018] FIG. 3 is an exploded perspective view of a cam-driven pump
in the grease gun in FIG. 1;
[0019] FIG. 4 is an enlarged operational cross sectional plan view
of the cam-driven pump mechanism in FIG. 3;
[0020] FIG. 5 is an enlarged operational cross sectional plan view
of a conventional grease gun pump mechanism in accordance with
prior art; and
[0021] FIG. 6 is an enlarged perspective view of a conventional
sliding block of the conventional pump mechanism in FIG. 5.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0022] With reference to FIGS. 1 and 2, a cam-driven pump mechanism
in accordance with present invention is used in a battery-powered
grease gun (not numbered). The battery-powered grease gun has a
body (10), a cartridge holder (50) and a cam-driven pump mechanism.
The body (10) comprises a casing (12) and a discharge assembly (not
numbered).
[0023] With further reference to FIG. 4, the casing (12) comprises
two half shells (not numbered) and has a top (not numbered) and an
inner chamber (121) formed when the half shells connect to each
other.
[0024] The discharge assembly is mounted on the top of the casing
(12) and comprises a transition body (11), a ball check valve (14)
and a discharge adapter (15). The transition body (11) has a top
(not numbered), a bottom (not numbered), an inward side (not
numbered), an outward side (not numbered), a grease channel (110),
a ball check valve housing (116) and a cartridge connector
(117).
[0025] The grease channel (110) is formed longitudinally through
the transition body (11) and has a top opening (111), a bottom
opening (112) and a supply port (114).
[0026] The cartridge connector (117) is formed on the inward side
of the transition body (11) around the supply port (114) to hold
the cartridge holder (50). The supply port (114) is defined on the
inward side of the transition body (11) inside the cartridge
connector (117) and communicates with the grease channel (110).
[0027] The ball check valve housing (116) is formed at the top of
the transition body (11) and is aligned with the top opening (111).
The ball check valve (14) is mounted in the ball check valve
housing (116) to keep grease from flowing back into the grease
channel (110) from the top opening (111).
[0028] The cartridge holder (50) is mounted on the top of the
casing (12), is connected to the cartridge holder connector (117)
of the transition body (11) and holds a lubricant cartridge (not
shown).
[0029] With further reference to FIG. 3, the cam-driven pump
mechanism comprises a cam driver (21) and a cam-driven pump (40).
The cam driver (21) is mounted in the inner chamber (121) and
includes a planetary gear assembly (30) and a motor (20). The
planetary gear assembly (30) comprises a set of planetary gears
(not numbered) and a gear housing (31). The gear housing (31) is
mounted in the casing (12) and has a top (not numbered), a bottom
(not numbered) and a lower inner chamber (311). The planetary gears
are mounted in the lower inner chamber (311).
[0030] The motor (20) is mounted in the casing (12) and is aligned
coaxially with and connects to bottom of the planetary gear
assembly (30) so that the set of planetary gears will reduce the
output speed and increase the output torque of the motor (20).
[0031] The cam-driven pump (40) comprises a cylindrical cam (41), a
follower (42), a sliding block (43), a piston (44) and a bushing
(45).
[0032] The cylindrical cam (41) is mounted rotatably between the
transition body (11) and the gear housing (31), is connected to,
aligned with and driven by the planetary gears and has an outside
surface (not numbered), a bottom end (not numbered), an eccentric
annular groove (411) and a drive shaft (412). The eccentric annular
groove (411) is formed in the outside surface. The drive shaft
(412) is rectangular, is formed on the bottom end and connects to
the planetary gears so the motor (20) will rotate the cylindrical
cam (41) through the planetary gear assembly (30).
[0033] The sliding block (43) is mounted slidably in the inner
chamber (121) and has a front (not numbered), a top (not numbered),
a follower hole (431) and a piston slot (432). The follower hole
(431) is formed in the front of the sliding block (43). The piston
slot (432) is formed in the top of the sliding block (43) and is
aligned with the grease channel (110) in the transition body
(11).
[0034] The follower (42) is a rod and has a distal end (421) and a
proximal end (422). The proximal end (422) is mounted securely in
the follower hole (431) in the sliding block (43). The bushing (45)
is mounted around the follower (42), and the distal end (421) of
the follower (42) and the bushing (45) are mounted slidably in the
eccentric annular groove (411). When the cylindrical cam (41)
rotates, the follower (42) is driven alternately up and down by the
eccentric annular slot (411).
[0035] The piston (44) has a distal end (not numbered), a proximal
end (not numbered) and an annular groove (441). The annular groove
(441) is formed around the piston (44) near the proximal end and is
engaged with the piston slot in the sliding block (43). The distal
end is mounted slidably in the grease channel (110), moves
reciprocally in the grease channel (110) and pumps grease out of
the grease channel (110) through the discharge adapter (15).
[0036] Consequently, use of the cylindrical cam (41) avoids
localized friction and uneven wear on the sliding block (43).
Furthermore, the bushing (45) mounted around the follower (42) and
in the eccentric annular groove (411) keeps the follower (42) and
the eccentric annular groove (411) from wearing excessively. The
bushing (45) is inexpensive and can be easily replaced to restore
the cam-driven pump (40) to a virtually new condition. The
cam-driven pump mechanism in accordance with the present invention
is durable and operates more efficiently and smoothly than the
conventional pump mechanism. The durable pump mechanism extends the
life of the grease gun.
[0037] Even though numerous characteristics and advantages of the
present invention have been set forth in the foregoing description,
together with details of the structure and function of the
invention, the disclosure is illustrative only, and changes may be
made in detail, especially in matters of shape, size, and
arrangement of parts within the scope of the appended claims.
* * * * *