Abstrict An oil filter crusher includes an elongated triangular frame, a
threaded drive screw, and a ram assembly, but does not include any
actuator for driving the screw. Rather, a first end of the drive
screw has a drive head to which a user may couple a conventional
wrench, such as a pneumatic impact wrench of the type commonly used
in automotive service centers. A thrust bearing assembly couples
the second end of the drive screw to the ram assembly. A threaded
portion of the drive screw engages a threaded opening in a portion
of the frame. The ram assembly thus moves in an axial direction
in response to rotation of the drive screw with respect to the frame.
Rotating the drive screw in one direction moves it toward the filter
to be crushed, and rotating it in the opposite direction moves it
away from the filter.
Claims What is claimed is:
1. An oil filter crusher, comprising:
a threaded drive screw having a shaft extending between first and
second ends and a drive head at said first end;
an elongated frame having first and second ends and a drive nut
having a threaded drive opening engaging said drive screw at said
first end, said drive nut being made of a metal dissimilar to a
metal from which said shaft of said drive screw is made; and
a ram assembly, said ram assembly including a thrust bearing assembly
coupling said ram assembly to said second end of said drive screw,
said ram assembly moving toward and away from said second end of
said frame in response to rotation of said drive screw with respect
to said frame.
2. The oil filter crusher recited in claim 1 wherein said frame
comprises a first triangular plate, a second triangular plate, and
three shafts extending between said first and second triangular
plates.
3. The oil filter crusher recited in claim 1 wherein said ram
assembly comprises at least one triangular plate.
4. The oil filter crusher recited in claim 1 wherein said frame
comprises at least one mounting bracket.
5. The oil filter crusher recited in claim 1 wherein said drive
head is polygonal.
6. The oil filter crusher recited in claim 1 further comprising
a resilient bumper disposed between said ram assembly and a portion
of said frame.
7. An oil filter crusher, comprising:
a threaded drive screw having a shaft extending between first and
second ends and a drive head at said first end;
an elongated frame having a first triangular plate at a first end,
a second triangular plate at a second end, and three shafts extending
between said first and second triangular plates, said frame having
a threaded drive opening engaging said drive screw at said first
end; and
a ram assembly at said second end of said drive screw, said ram
assembly including a third triangular plate substantially aligned
with said first and second triangular plates and having openings
engaging said three shafts, said ram assembly moving toward and
away from said second end of said frame in response to rotation
of said drive screw with respect to said frame.
8. The oil filter crusher recited in claim 7 wherein said ram
assembly comprises:
a fourth triangular plate substantially aligned with said third
triangular plate and having openings engaging said three shafts;
and
a spacer connecting said third and fourth triangular plates.
9. The oil filter crusher recited in claim 7 further comprising
a top mounting bracket at said first end of said frame and a bottom
mounting bracket at said second end of said frame.
10. An oil filter crusher, comprising:
a threaded drive screw having a shaft extending between first and
second ends and a polygonal drive head at said first end;
an elongated frame having a first triangular plate at a first end,
a second triangular plate at a second end, and three shafts extending
between said first and second triangular plates, said frame having
a threaded drive opening engaging said drive screw at said first
end;
a ram assembly at said second end of said drive screw, said ram
assembly including third and fourth triangular plates substantially
aligned with said first and second triangular plates, each of said
third and fourth triangular plates having openings engaging said
three shafts, said ram assembly moving toward and away from said
second end of said frame in response to rotation of said drive screw
with respect to said frame; and
wherein said oil filter crusher does not include any actuator for
rotating said drive screw.
11. The oil filter crusher recited in claim 10 further comprising
a thrust bearing assembly coupling said ram assembly to said second
end of said drive screw.
12. An oil filter crusher, comprising:
a threaded drive screw having a shaft extending between first and
second ends and a drive head at said first end;
an elongated frame having first and second ends, a threaded drive
opening engaging said drive screw at said first end, and a retainer
at said second end for disposing an oil filter therein, said retainer
having a drain for collecting residual oil extracted from said filter;
and
a ram assembly, said ram assembly including a thrust bearing assembly
coupling said ram assembly to said second end of said drive screw,
said ram assembly moving toward and away from said second end of
said frame in response to rotation of said drive screw with respect
to said frame.
13. The oil filter crusher recited in claim 12 wherein said frame
comprises a first triangular plate, a second triangular plate, and
three shafts extending between said first and second triangular
plates.
14. The oil filter crusher recited in claim 12 wherein said ram
assembly comprises at least one triangular plate.
15. The oil filter crusher recited in claim 12 wherein said frame
comprises at least one mounting bracket.
16. The oil filter crusher recited in claim 12 wherein said drive
head is polygonal.
17. The oil filter crusher recited in claim 12 further comprising
a resilient bumper disposed between said ram assembly and a portion
of said frame.
18. The oil filter crusher recited in claim 12 wherein said frame
comprises a drive nut having said threaded drive opening, and said
drive nut is made of a metal dissimilar to a metal from which said
shaft of said drive screw is made.
19. An oil filter crusher, comprising:
a threaded drive screw having a shaft extending between first and
second ends and a drive head at said first end;
an elongated frame having first and second ends and a threaded
drive opening engaging said drive screw at said first end;
an openable safety door coupled to said frame; and
a ram assembly, said ram assembly including a thrust bearing assembly
coupling said ram assembly to said second end of said drive screw,
said ram assembly moving toward and away from said second end of
said frame in response to rotation of said drive screw with respect
to said frame.
20. The oil filter crusher recited in claim 19 wherein said frame
comprises a first triangular plate, a second triangular plate, and
three shafts extending between said first and second triangular
plates.
21. The oil filter crusher recited in claim 19 wherein said ram
assembly comprises at least one triangular plate.
22. The oil filter crusher recited in claim 19 wherein said frame
comprises at least one mounting bracket.
23. The oil filter crusher recited in claim 19 wherein said drive
head is polygonal.
24. The oil filter crusher recited in claim 19 further comprising
a resilient bumper disposed between said ram assembly and a portion
of said frame.
25. The oil filter crusher recited in claim 19 wherein said frame
comprises a drive nut having said threaded drive opening, and said
drive nut is made of a metal dissimilar to a metal from which said
shaft of said drive screw is made.
26. The oil filter crusher recited in claim 1 wherein said safety
door is transparent.
Description CROSS-REFERENCE TO RELATED APPLICATION
The benefit of the filing date of U.S. Provisional Application
Ser. No. 60/019130 filed Jun. 3 1996 is claimed.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to compacting and crushing
devices and, more specifically, to an oil filter crusher that can
be operated by a conventional pneumatic or electric impact wrench.
2. Description of the Related Art
Automotive service centers, including commercial truck fleet service
centers, in the United States and other countries change millions
of automobile and truck oil filters each year. Retail automotive
supply stores sell millions of oil filters to people who change
their own vehicle's oil. Oil filters of various sizes and types
are known, but an oil filter generally consists of a metal housing
in which is disposed a paper filter element.
An oil filter crusher is used to crush or compact an oil filter
that has been removed from an automobile or other vehicle after
a period of use. Not only does compaction facilitate temporary bulk
storage of used oil filters by minimizing their volume, but it also
facilitates recovery of residual oil that has economic value. Although
many types of oil filter crushers are known, a conventional oil
filter crusher typically includes a reciprocating ram that is driven
by a hydraulic or electric actuator. When a filter is positioned
in the crusher, the actuator drives the ram toward the filter. The
residual oil that drains from the filter during crushing may collect
in a pan or container. After crushing, the actuator retracts the
ram. The crushed filter may then be removed for disposal or recycling
as scrap metal.
Conventional oil filter crushers are uneconomical because they
typically include, among other uneconomical components, an integral
hydraulic, pneumatic or electric actuator. Although certain service
centers may change a sufficient number of oil filters per year to
justify the cost of purchasing a conventional oil filter crusher,
the majority of service centers do not. Furthermore, many conventional
oil filter crushers are intended for bulk operation and are simply
too large to be conveniently located in a typical service center.
For these reasons, smaller service centers typically send their
(uncrushed) collected filters to a regional oil filter recycling
service, which then crushes the filters in bulk.
Oil filter crushers not having powered actuators are known in the
art. U.S. Pat. No. D355425 issued to Weaver, shows an oil filter
crusher having a threaded drive screw with a hexagonal head. The
crusher is of a simplistic design, with a disc-shaped ram apparently
fixedly mounted on the end of the drive screw opposite the end having
the hexagonal head. U.S. Pat. No. 5274906 issued to ter Haar,
describes an oil filter crusher having a threaded screw drive that
may be driven using a pneumatic wrench. Nevertheless, its design
is uneconomical. Furthermore, although the end of the drive screw
is rotatably mounted to the ram, the rotatable mounting appears
prone to substantial frictional resistance.
It would be desirable to provide an economical oil filter crusher
that can be quickly and easily used by automotive service center
personnel. The crusher should be easy to use and unobtrusive. Such
a crusher would be desirable not only to automotive service centers
but also to retail automotive supply stores, which could offer a
crushing service to people who purchase filters from them to complement
the used oil recovery services that many such stores currently offer.
These needs are clearly felt in the art and are satisfied by the
present invention in the manner described below.
SUMMARY OF THE INVENTION
The present invention relates to an oil filter crusher that includes
an elongated frame, a threaded drive screw, and a ram assembly,
but does not include any actuator for driving the screw. Rather,
a first end of the drive screw has a drive head to which a user
may couple a conventional wrench, such as a pneumatic impact wrench
of the type commonly used in automotive service centers. A thrust
bearing couples the second end of the drive screw to the ram assembly.
A threaded portion of the drive screw engages a threaded opening
in a portion of the frame. The ram assembly thus moves in an axial
direction in response to rotation of the drive screw with respect
to the frame. Rotating the drive screw in one direction moves it
toward the filter to be crushed, and rotating it in the opposite
direction moves it away from the filter.
The inclusion of a drive head, such as a hexagonal bolt head, to
which a conventional wrench may be coupled to drive the screw and
the exclusion of an uneconomical actuator enables the invention
to be manufactured economically and sold to lower-volume service
centers that might not purchase a less economical oil filter crusher.
Not only does this arrangement maximize economy, but it also enhances
ease of use. Service center personnel almost always have pneumatic
impact wrenches close at hand, and they are comfortable using such
wrenches. Service center personnel rely upon impact wrenches and
will immediately recognize the practical association of the crusher
of the present invention with the ease and efficiency of operation.
To crush a filter, the user may simply place the filter at the second
end of the frame, engage the drive head with the impact wrench socket,
and activate the wrench. In response to the rotation of the screw,
the ram assembly moves toward the second end of the frame and crushes
the filter. Although a user may alternatively drive the screw manually
using a hand wrench, a power wrench of the type commonly used in
automotive service centers is preferred.
Furthermore, the thrust bearing provides important advantages.
In the absence of a thrust bearing, the friction between the ram
assembly and the filter would inhibit crushing, and the applied
torque could damage the drive screw and other parts.
The foregoing, together with other features and advantages of the
present invention, will become more apparent when referring to the
following specification, claims, and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference
is now made to the following detailed description of the embodiments
illustrated in the accompanying drawings, wherein:
FIG. 1 is a rear view of an oil filter crusher;
FIG. 2 is a sectional view taken on line 2--2 of FIG. 1;
FIG. 3 is a sectional view taken on line 3--3 of FIG. 2;
FIG. 4 is a sectional view taken on line 4--4 of FIG. 2;
FIG. 5 is a sectional view taken on line 5--5 of FIG. 2;
FIG. 6 is a sectional view taken on line 6--6 of FIG. 2;
FIG. 7 is a side elevation view with the near protective door removed
for purposes of clarity, showing the crushing action using an impact
wrench.
DESCRIPTION OF A PREFERRED EMBODIMENT
As illustrated in FIGS. 1-6 a preferred oil filter crusher includes
a drive screw 10 having a hexagonal drive head 12. The oil filter
crusher further includes a triangular top plate 14 a triangular
bottom plate 16 and three guide shafts 18 20 and 22 that define
a frame. Screw fasteners 24 which are preferably grade 5 or above
standard nuts and bolts, fasten the upper ends of shafts 18 20
and 22 to top plate 14 and the lower ends of shafts 18 20 and 22
to bottom plate 16. Shafts 18 20 and 22 are fastened to portions
of plates 14 and 16 that are adjacent to their corners or vertices.
The frame further includes a top mounting bracket 26 fastened to
upper plate 14 and a bottom mounting bracket 28 fastened to lower
plate 16.
The triangular shape of the frame maximizes manufacturing economy
because only three guide shafts 18 20 and 22 and their associated
fasteners 24 are used. A frame having more than three guide shafts
would be more in line with conventional machinery design principles
but is less preferable because it would be less economical. A frame
having fewer than three guide shafts is less preferable because
it could be damaged in response to relative torque between the frame
and drive screw during use.
The frame further includes a drive nut 30 fastened to the lower
surface of upper plate 14. Drive nut 30 has a threaded opening in
which drive screw 10 is engaged. To inhibit frictional binding or
seizing, drive nut 30 is preferably made of a metal dissimilar to
that of which drive shaft 10 is made. For example, drive shaft 10
may be made of cold-rolled steel, and drive nut 30 may be made of
brass. Furthermore, the play or size differential between the interengaging
surfaces of the threads of drive nut 30 and the threads of drive
shaft 10 is preferably slightly greater than that of a conventional
mating nut and screw to further inhibit binding when torque is applied.
A ram assembly 32 is mounted on the end of drive screw 10 opposite
that at which drive head 12 is mounted. Ram assembly 32 includes
a cylindrical ram spacer 34 a lower ram plate 36 and an upper ram
plate 38.
Ram plates 36 and 38 are preferably welded to ram spacer 34. Ram
plates 36 and 38 have openings adjacent their corners or vertices
through which guide shafts 18 20 and 22 extend. Ram assembly 32
is thus slidable upwardly and downwardly between upper and lower
plates 14 and 1 6 on guide shafts 18 20 and 22.
An externally lubricated dedicated ball-type thrust bearing assembly
40 is fastened to the upper surface of upper ram plate 38 by additional
fasteners 24. As shown in FIG. 2 thrust bearing assembly 40 includes
a load-bearing washer 41 and bearing races 42 and 44 between which
are captured ball bearings 46. A grease fitting 43 also known as
a Zerk fitting, allows external lubrication. The end of drive screw
20 is fastened to thrust bearing assembly 40 by a nut 48. Thrust
bearing assembly 40 is an important feature of the invention because
it minimizes frictional forces, thereby allowing a greater compaction
force to be applied.
A bumper ring 50 made of a suitable resilient material such as
polyurethane is disposed around drive screw 10 between two bumper
washers 52 and 54. Bumper ring 50 and washers 52 and 54 are all
disposed between the upper portions of thrust bearing assembly 40
and the lower portions of drive nut 30. A nut 56 machined to have
a rounded outside surface, is disposed between bumper washer 54
and thrust bearing assembly 40 and secured to drive screw 10 by
a pin 58 extending diametrically therethrough. Nut 56 transmits
the load from drive screw 10 to thrust bearing assembly 40.
The oil filter 60 to be crushed may be placed in a retaining ring
62 which is mounted, preferably by welding, to the upper surface
of bottom plate 16. A threaded end of a nipple 64 engages the opening
in bottom plate 16 to provide a path for oil to drain as filter
60 is crushed. A hose 66 may be attached to the other end of nipple
64 by a hose clamp 68 or other suitable means.
To guard against fingers and unwanted objects accidentally entering
the crusher during operation, the frame includes two safety doors
70 and 72 that are preferably made of transparent high-impact plastic,
such as PLEXIGLAS. Safety door 70 is mounted on hinge pins 74 and
76 to top plate 14 and bottom plate 16 respectively. Safety door
72 is mounted on hinge pins 78 and 80 to top plate 14 and bottom
plate 16 respectively. Each end of a spring 82 is attached to one
of doors 70 and 72 to bias them closed.
The oil filter crusher is preferably mounted on a wall of a building,
such as an automotive service center, using mounting brackets 26
and 28. This mounting feature not only braces the frame of the crusher
against turning but also enables the crusher to be mounted relatively
unobtrusively in the building. In certain embodiments of the invention
the triangular cross-sectional shape of the frame may facilitate
mounting it in a manner that further braces it against movement
when torque is applied to drive screw 10. For example, although
in the illustrated embodiment the frame has a cross-sectional shape
similar to an equilateral triangle, in other embodiments the frame
may have a shape similar to a right triangle. If such a crusher
is mounted such that the ninety degree vertex of the triangular
frame is disposed in a corner where two walls of the building meet,
the crusher would be securely braced against undesirable turning.
To crush a filter 60 the user opens one of safety doors 70 and
72 places filter 60 in retaining ring 62 on bottom plate 16 and
removes his hand, allowing the door to swing shut. Filter 60 is
preferably placed in an orientation such that its opening (not shown)
is on bottom plate 16. As illustrated in FIG. 7 the user preferably
engages drive head 12 with a power wrench 84 such as a pneumatic
impact wrench of the type commonly used in automotive service centers.
Power wrench 84 has a socket 86 with a hexagonal opening that corresponds
to the hexagonal shape of drive head 12.
The user then activates wrench 84. Wrench 84 applies torque to
drive head 12 thereby rotating drive screw 10. Drive head 12 is
preferably made of case-hardened steel to withstand the torque applied
to it under repeated use. In response to the rotation, drive screw
10 moves axially downwardly in drive nut 30 urging ram assembly
32 into contact with filter 60. As ram assembly 32 moves downwardly,
filter 60 is crushed between lower ram plate 36 and bottom plate
16. The residual oil is squeezed out of filter 60 directly into
the drain opening in bottom plate 16 because the opening in filter
60 is directly above the drain opening in bottom plate 16. Retaining
ring 62 centers filter 60 over the opening in bottom plate 16 and
retains filter 60 in that position during crushing. Retaining ring
62 thus also centers filter 60 directly below ram assembly 32 where
filter 60 receives maximum crushing force.
The triangular shape of the frame provides exceptional strength
and resistance to deformation as a result of the applied torque.
The crushing force is dissipated through the frame and evenly distributed
among guide shafts 18 20 and 22 because they are symmetrically
arrayed with respect to filter 60 ram assembly 32 and drive screw
10.
When the user observes that filter 60 has been sufficiently crushed
or, alternatively, when wrench 84 resists further application of
torque, the user reverses the direction of wrench 84. In response
to the reverse rotation, drive screw 10 moves axially upwardly in
drive nut 30. Because there is essentially no resistance to the
torque applied, drive screw 10 and ram assembly 32 may move upwardly
very rapidly. The movement may be too rapid for the user to precisely
stop wrench 84 when ram assembly 32 has risen a sufficient distance
to remove the crushed filter and position another filter to be crushed.
Resilient bumper 50 absorbs the impact if ram assembly 32 should
rise too rapidly for a user to stop it before it hits bumper 50
thereby preventing excessive wear or damage to the parts.
The oil filter crusher of the present invention may be manufactured
in any suitable size to accommodate any type of automobile or truck
oil filters. Although the triangular shape is economical and enhances
bracing, other shapes are suitable. In addition, thrust bearing
assembly 40 allows application of very large crushing forces that
could otherwise damage the crusher. The crusher is easy to operate
with existing power tools that are readily available to automotive
service personnel. Nevertheless, it can be operated manually using
a hand wrench or similar hand tool.
Obviously, other embodiments and modifications of the present invention
will occur readily to those of ordinary skill in the art in view
of these teachings. Therefore, this invention is to be limited only
by the following claims, which include all such other embodiments
and modifications when viewed in conjunction with the above specification
and accompanying drawings.
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