Note: Descriptions are shown in the official language in which they were submitted.
`` 132~178
This invention relates to fluid filters
and, more particularly, to fluid filters of the
type used in transmissions to filter the
transmission fluid.
Transmission fluid filters are well known
and generally consist of two main housinq members
and a sheet of folded filter media material. The
folded filter media sheet is mounted with the
abutting marginal edge portions thereof disposed
between approximately three-quarters of the
marginal peripheral edges of the two housing
members. The entire peripheral edges of the
housing members are then crimped together to
provide a peripheral seal. Flow through the
1~ filter assembly is first through an inlet into the
interior provided by the filter media sheet
inwardly of the folded edge and crimped abutting
edges thereof. After passing through the filter
media sheet, the fluid exits from the space
between the exterior of the filter media sheet and
the interior of the peripherally sealed housing
members through a suction spout. The filter
assembly is operatively positioned in the
transmission unit in the fluid collecting pan or
2~ bottom of the housing and a pump is provided for
drawing the fluid upwardly throuqh the filter
spout with the flow of fluid into the filter inlet
being accomplished from the pool of transmission
fluid in the pan.
Heretofore, the filter housing members
have been made of stamped sheet metal. In units
of this type, the seal around the periphery of the
two housing sheet metal members has utilized a
resilient peripheral sealin~ element in order to
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; insure a fluidtight seal as is necessary to
prevent contaminated fluid from bypassing the
filter media. The necessity to assemble the fluid
filter components with a resilient peripheral seal
complicated the assembly, led to waste and
increased the cost. In order to alleviate this
problem, it has been the practice in recent years
to mold one of the housing members out of plastic
- material. This enabled the peripheral edge of the
plastic molded housing member to be shaped in a
bead formation so that the other metal housing
member could be crimped thereover to form a
peripheral seal without the necessity of a
separate resilient sealing element. See, for
example, U. S. Patent Nos. 4,450,081 and
4,402,827. While an arrangement of this type has
; eliminated the assembly problems, wastage and cost
; incident to the prior practice of providing a
resilient peripheral sealing element, nevertheless
the necessity to mold a plastic component has
increased the cost of the components. There still
exists a need to provide a transmission fluid
filter assembly which eliminates the disadvantages
inherent in both types of prior art fluid filter
assemblies as noted above.
It is an object of the present invention
to fulfill the aforesaid need. In accordance with
the principles of the present invention, this
objective is accomplished by providing a
transmission fluid filter assembly in which the
housing members are both formed of sheet metal and
the marginal peripheries of the two sheet metal
members are crimped into a plied peripheral
structure. The plied peripheral structure is
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formed from a first marginal free edge portion and
an adjacent marginal edge portion of a first sheet
metal member and a second marginal free edge
portion of a second sheet metal member. The
members are assembled with the second marqinal
free edge portion of the second sheet metal member
disposed in generally coextensive facing relation
with the adjacent marginal edge portion of the
first sheet metal member and with the remaining
abutting edge portions of the folded filter media
sheet member therebetween and the folded edge
portion of the filter media sheet member disposed
therewithin. The first marginal free edge portion
of the first sheet metal member is then bent over
the second marginal free edge portion of the
second sheet metal member in compressing relation
with respect to the remaining abutting edge
portions of the filter media sheet member so as to
form the plied peripheral structure. In
accordance with the principles of the present
invention, the plied peripheral structure is then
angularly bent intermediate the bent-over outer
edge and the free edge of the first marginal edge
portion in a direction to form an included angle
between the exterior surface of an outer section
and the exterior surface of an inner section of
the first marginal edge portion sufficient to
cause the bias imparted thereto by the angular
bend to act in such a way as to increase the
interengagement of the plied peripheral structure
enabling the latter to provide a fluidtight
: peripheral seal therewithin without the use of a
- separate resilient sealing element. In this way,
the present invention eliminates both the need for
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132~178
the resilient sealing element and secures the cost
advantage of utilizing a second sheet metal
housing member instead of the more expensive
molded plastic member.
Another object of the present invention is
to provide a transmission fluid filter assembly of
the type described which is simple in
construction, effective in operation and
economical to manufacture.
These and other objects of the present
invention will become more apparent during the
course of the following detailed description and
- appended claims.
IN THE DRAWINGS:
Figure 1 is a bottom plan view of a
transmission fluid filter assembly embodying the
principles of the present invention;
Figure 2 is an enlarged sectional view
taken along the line 2-2 of Figure 1;
Figure 3 is an enlarged sectional view
taken along the line 3-3 of Figure l;
Figure 4 is an enlarged fragmentary
sectional view taken along the line 4-4 of Figure
l; and
Figure 5 is an enlarged fragmentary
sectional view taken along the line 5-5 of Figure
1.
Referring now more particularly to Figure
1 of the drawings, there is shown therein in
bottom plan view a transmission fluid filter
assembly, generally indicated at 10, which
;i embodies the principles of the present invention.
As shown, the assembly 10 includes a first or top
132~7~
sheet metal housing member, generally indicated at
12, and a bottom or second sheet metal housing
member, generally indicated at 14. As best shown
in Figure 1, the two housing members 12 and 14 in
plan have a quadrilateral configuration in which
three sides are perpendicular to one another with
the fourth side being angular and intersecting a
short perpendicular side at an obtuse angle and an
opposite longer side at an acute anqle. As shown,
the corners are all rounded. As indicated, while
a configuration of this shape is preferred, other
shapes may be utilized if desired.
The filter assembly 10 also includes a
filter media sheet member, generally indicated at
16, which is folded along one edge, as indicated
at 18 by the dotted line in Figure 1, so as to
provide remaining abutting edge portions 20 which
have generally the same shape as the shape of the
housing members 12 and 14 except that the short
and long walls are of lesser dimension.
The top sheet metal housing member 12 is
formed to provide a first marginal free edge
portion 22 and an adjacent marginal edge portion
24. The bottom sheet metal housing member 14 is
formed to provide a second marginal free edge
- portion 26. Formed in the bottom sheet metal
housing member 14 is a series of elongated
indentations 28. Formed in certain of the
indentations 28 are spaced V-shaped filter media
; 30 securing indentations 30. Similar elongated
indentations 32 and V-shaped filter securing
indentations 34 are also formed in the top sheet
met~l housing member 12 in positions to register
with the respective indentations 26 and 28 in the
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bottom sheet metal member 14. Formed along the
angular side of the bottom sheet metal housing
member 14 is an elongated projection 36 which
extends along the adjacent marginal edge portion
24 of the angular side then along the short side
and then halfway along the adjacent perpendicular
- side where it inclines down to a terminus at the level of the sheet metal member. Annular
elongated projection 38 is formed in the top sheet
metal housing member 12, however, its extent is
- limited to being coextensive with the slanted
side.
At a position transversely opposite the
inclined end of the elongated projection in the
bottom housing member 14 is another inclined
portion 40 formed in the sheet metal which extends
from the main body of the sheet metal member up to
the projection 36 at an adjacent portion thereof.
At a position within the U-shaped bend of the
projection 36, the bottom sheet metal member 14 is
formed with a quadrilaterally shaped opening and
the filter media sheet member is likewise provided
with a registering opening. The marginal edge
portion of the sheet metal of the bottom housing
member is crimped over the opening in the adjacent
ply of the filter media member to form an inlet
x'- 42. It will be noted that a guide cover plate 44
- is brazed or otherwise fixed to the projecting
surface of the U-shaped portion of the projection
36 at a position overlying the inlet 42 where the
transversely spaced inclines meet the projections.
In order to provide for an even support of the
- bottom member, a corner projection 46 is provided
in the opposite perpendicular corner and a smaller
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projection 48 is formed in the elongated
projection 32 at the adjacent end thereof.
As best shown in Figure 2, the top sheet
metal member 12 is formed with an opening 50
therein within which a spout 52 of metal is
mounted. The spout 52 includes an axially
extending flange 34 which is inserted within the
opening and bent over the metal defining the
opening 50 so as to secure the spout 52 to the
lG sheet metal member 12. It will be understood that
the configuration thus far described is
illustrative of conventional designs and it will
be understood that the configuration can be varied
as desired.
The present invention is more particularly
concerned with the manner in which the two sheet
metal housing members 12 and 14 are secured
together in peripherally sealed relation with
respect to the abutting edge portions 20 of the
folded filter media sheet member 16. As best
shown in Figure 1, the members 12, 14, and 16 are
assembled with the second marginal free edge
portion 26 of the bottom sheet metal housing
; member 14 disposed in generally coextensive facing
relation with the adjacent marginal edge portion
24 of the top sheet metal member 12 and with the
remaining abutting edge portions 20 of the filter
media sheet member 16 therebetween and with the
folded edge portion 18 of the filter media sheet
member 16 disposed therewithin in adjacent spaced
relation along the angular sides thereof as shown
in the broken line 18 indication in Figure 1. The
first marginal free edge portion 22 of the top
sheet metal housing member 12 is then bent over
~32~7 8
the second marginal free edge portion 26 of the
bottom sheet metal housing member 14 in
compressing relation with respect to the remaining
~- abutting edge portions 20 of the filter media
sheet member 16 so as to form a plied peripheral
structure, generally indicated at 56. This
bending operation defines the first marginal free
end portion 22 as being that peripheral portion of
the top sheet metal member 12 between the bent
over edge, indicated at 58, and the free edge,
indicated at 60.
In accordance with the principles of the
present invention, the plied peripheral structure
56 is then bent angularly intermediate the
bentover outer edge 58 and the free edge 60 of the
~ first marginal edge portion 22 in a direction to
.~ form an included angle between an exterior surface62 of an outer section and an exterior surface 64
of an inner section of the first marginal edge
portion 22. Stated differently, the direction of
the bend is toward the bottom sheet metal member
14. As shown, a preferred included angle is of
90-. The angle can be varied so long as it is
sufficient to cause the bias imparted to the plied
peripheral structure 56 by the angular bend to act
in such a way as to increase the interengagement
of the plied peripheral structure 56 enabling the
latter to provide a fluidtight peripheral seal
therewithin without the use of a separate
resilient sealing element. It will be noted that
the inner and outer sections of the first marginal
free edge portion 22 are biased in such a way as
to tend to increase the an~le between the surfaces
62 and 64. This bias moves the marginal free end
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portion 22 more tightly into the engagement with
the bent portion of the second marginal free edge
portion 26 against which it abuts. This
interengagement serves to provide an effective
seal which is effective not only where the filter
media sheet material is compressed therebetween as
shown in Figure 4, but, more importantly, in those
extents of the periphery where there are no
abutting edge portions of the filter media
material in the plied peripheral structure 56.
This is along the angular side and the
cross-sectional configuration is illustrated in
Figure 5.
In operation, it will be understood that
the fluid filter assembly 10 is mounted within the
space of the transmission unit where the main body
of the transmission fluid is retained, i.e. the
pan or bottom of the housing. The assembly 10 is
mounted with the bottom housing member 14
lowermost and the spout 52 extending upwardly.
The spout 52 is connected with suitable conduit
(not shown) leading from the suction side of the
pump which causes the flow of transmission fluid
in the main body of the transmission housing to
enter through the inlet 42 into the interior of
the filter media sheet member 16 inwardly of the
folded edge portion 18 thereof and the abutting
edge portions 20 thereof compressed within the
plied peripheral structure 56. The fluid passes
from the interior space through the filter media,
with the V-shaped indentations serving to grip the
filter media and retain it in a proper
relationship and the other indentations serving to
permit a controlled billowing of the filter media
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sheet material in such a way that it does not
- collapse upon the support but provides for flow
therethrough to the space defined by the exterior
thereof and the interior of the top and bottom
sheet metal members within the plied peripheral
structure thereof. In this reqard, the
projections 36 and 38 define with the folded edge
portion 18 of the filter media sheet member 16, a
header space leading to the spout 52. It is noted
that the entire space between the exterior of the
filter member 16 and exterior of the housing
- members 12 and 14 which is communicated directly
to the source of suction is provided with an
effective peripheral seal which prevents the flow
of contaminated transmission fluid directly into
X this space bypassing the filter media, by virtue
~`~ of the plied peripheral structure 56 constructed
in accordance with the principles of the present
invention.
It thus will be seen that the objects of
this invention have been fully and effectively
accomplished. It will be realized, however, that
the foregoing preferred specific embodiments have
been shown and described for the purpose of
illustrating the functional and structural
principle~ of this invention and are subject to
change without departure from such principles.
Therefore, this invention includes all
modifications encompassed within the spirit and
scope of the following claims.
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