U.S. patent application number 11/735008 was filed with the patent office on 2007-08-09 for co-molded and cured filter cartridge end using different durometer plastisols.
This patent application is currently assigned to PUROLATOR FILTERS NA LLC. Invention is credited to Allen B. WRIGHT.
Application Number | 20070182043 11/735008 |
Document ID | / |
Family ID | 36385102 |
Filed Date | 2007-08-09 |
United States Patent
Application |
20070182043 |
Kind Code |
A1 |
WRIGHT; Allen B. |
August 9, 2007 |
CO-MOLDED AND CURED FILTER CARTRIDGE END USING DIFFERENT DUROMETER
PLASTISOLS
Abstract
A filter cartridge includes a filter media having opposed edges.
Annular end discs include first and second surfaces defined by
spaced apart planes. The end discs has an integrated gasket, and is
formal from includes first and second plastisol materials that have
different durometers. The durometer of the second plastisol
material makes it more rigid than the first plastisol material. The
first plastisol material provides a flexible gasket. During
manufacture, each edge of the filter media is embedded into the
second material on an end disc. The second plastisol material is
arranged between the planes, and the first plastisol material
extends axially away from the second surface.
Inventors: |
WRIGHT; Allen B.; (Hope
Mills, NC) |
Correspondence
Address: |
CROWELL & MORING LLP;INTELLECTUAL PROPERTY GROUP
P.O. BOX 14300
WASHINGTON
DC
20044-4300
US
|
Assignee: |
PUROLATOR FILTERS NA LLC
3200 Natal Road
Fayetteville
NC
28306
|
Family ID: |
36385102 |
Appl. No.: |
11/735008 |
Filed: |
April 13, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10991747 |
Nov 18, 2004 |
|
|
|
11735008 |
Apr 13, 2007 |
|
|
|
Current U.S.
Class: |
264/35 |
Current CPC
Class: |
B01D 2201/293 20130101;
B01D 2201/34 20130101; B01D 29/111 20130101 |
Class at
Publication: |
264/035 |
International
Class: |
E04B 1/00 20060101
E04B001/00 |
Claims
1. A method of manufacturing a filter cartridge comprising the
steps of: a) dispensing a first polymer material in a first cavity;
b) dispensing a second polymer material in a second cavity
communicating with the first cavity; c) embedding a filter media in
the second polymer material; and d) curing the first and second
polymer materials.
2. The method according to claim 1, wherein the first polymer
material provides a gasket and the second polymer material provides
an end disc.
3. The method according to claim 1, wherein the second polymer
material flows radially outwardly during step b) forming inner and
outer circumferential surfaces, the first polymer material arranged
radially outward of the inner circumferential surface.
4. The method according to claim 1, wherein the second polymer
material provides first and second surfaces defining spaced apart
planes, the filter media extending through the first surface, the
first polymer material extending axially outward from the second
surface.
5. The method according to claim 1, comprising the steps of: e)
dispensing the first polymer material in a third cavity; f)
dispensing the second polymer material in a fourth cavity
communicating with the third cavity; g) reorienting the filter
media; h) embedding the filter media in the second polymer material
in the fourth cavity; and i) curing the first and second polymer
materials in the third and fourth cavities.
6. The method according to claim 1, wherein the first and second
polymer materials are plastisol.
7. The method according to claim 1, wherein the second cavity is
arranged axially above the first cavity.
Description
[0001] This application is a divisional of pending U.S. patent
application Ser. No. 10/991,747, filed Nov. 18, 2004, the
disclosure of which is expressly incorporated by reference
herein.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a filter cartridge for use in a
fluid filter and to a method of manufacturing the same.
[0003] Filter cartridges are used in filter housings for filtering
fluids such as oil and fuel. A filter cartridge typically includes
spaced apart metal end discs with a filter media or element
arranged between the end discs. Edges of the filter element, which
may be a pleated paper element, are bonded to the end discs with an
adhesive such as plastisol.
[0004] The surfaces of the end disc opposite of the filter element
seal against the filter housing to prevent fluid from bypassing the
filter element. The filter housing is typically constructed of
metal so that there is a metal-to-metal seal between the filter
cartridge end discs and the filter housing. This type of seal
requires high control of the mating surfaces and preload to ensure
a good seal. To improve the seal between the filter cartridge and
filter housing, gaskets are sometimes bonded to the surfaces of the
end discs opposite the filter element. Separately bonding a gasket
to the metal end discs adds cost and time to the manufacture filter
cartridge.
[0005] Integrated plastisol end discs and gaskets have been
proposed in the prior art for other applications in which the end
disc and gasket are made out of differing plastisols. However, the
plastisol providing the flexible gasket is arranged radially inward
of a central opening in the end discs. The end disc plastisol and
gasket plastisol may well run together during the manufacturing
process. This is not an issue in the prior art since a sealing load
is applied in a radial direction. However, for filter cartridges
configured, like those using metal end discs described above, the
sealing load is applied axially. An axial sealing load requires a
rigid end disc across the width of the filter element.
[0006] What is needed is a filter cartridge having improved,
integrated end discs and gaskets and a method for making the
same.
SUMMARY OF THE INVENTION
[0007] One example of a filter cartridge of the present invention
includes a filter media having an edge. An annular end disc
includes first and second surfaces defined by spaced apart planes.
An end disc and integrated gasket includes first and second
plastisol materials that are different from one another and have
different durometers. The durometer of the second plastisol
material makes it more rigid than the first plastisol material. The
first plastisol material provides a flexible gasket.
[0008] In one embodiment, the edge of the filter media is embedded
into the second plastisol material. The second plastisol material
is arranged between the planes, and the first plastisol material
extends axially away from the second surface. This arrangement of
the first and second plastisol materials better ensures that the
materials do not mix with one another during dispensing and curing.
The arrangement of the first and second plastisol materials
provides a generally uniform rigidity across the width of the end
disc ensuring better support of the filter media.
[0009] Accordingly, the present invention provides a filter
cartridge having improved, integrated end discs and gaskets and a
method making the same.
[0010] These and other features of the present invention can be
best understood from the following specification and drawings, the
following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a cross-sectional view of one prior art filter
cartridge.
[0012] FIG. 2A is a top elevational view of a mold utilized in
forming the inventive integrated end disc and gasket.
[0013] FIG. 2B is a cross-sectional view of the mold taken along
lines 2B-2B of FIG. 2A.
[0014] FIG. 3 illustrates dispensing of a first plastisol material
into the mold.
[0015] FIG. 4 illustrates dispensing a second plastisol material
into the mold.
[0016] FIG. 5 is a cross-sectional view of a portion of the
inventive filter cartridge curing in an oven.
[0017] FIG. 6 is a cross-sectional view of a completed filter
cartridge utilizing one example method of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] FIG. 1 illustrates one prior art filter cartridge for fluid
filters. The filter cartridge 12 is arranged within a filter
housing 10, which is depicted schematically. The filter housing 10
includes filter structure 14 against which the filter cartridge 12
must seal to prevent fluid from bypassing the filter cartridge 12.
The filter cartridge 12 typically includes metal end discs 16 that
retain a filter media or element 18. Adhesive 20 is arranged on one
side of the end discs for securing edges 21 of the filter media 18
to the end discs 16. The filter media 18 is a pleated paper filter
element in the example shown.
[0019] To better ensure that the filter cartridge seals against the
filter structure 14, gaskets 22 are bonded to sides of the end disc
16 opposite the edges 21. The arrangement shown in FIG. 1 is costly
since it requires separately adhering a gasket to each end disc.
Further, the metal end discs cannot be incinerated when disposing
of the filter.
[0020] An example inventive method of producing an inventive end
disc uses the mold 24 depicted in FIGS. 2A-2B. The mold 24 can be
constructed of any suitable material, such as metal, ceramic,
plastic or glass. The mold 24 includes a first annular cavity 26 or
recess that provides the shape of the inventive gasket. A second
annular cavity 28 that, in this embodiment, is wider than the first
annular cavity 26 is arranged axially above the first annular
cavity 26 for reasons that will be described in greater detail
below. The second annular cavity 28 provides inner and outer
peripheral surfaces 27 and 29.
[0021] Referring to FIG. 3, a first plastisol material 32 is
dispensed from a first dispenser 30 into the first annular cavity
26. A second plastisol material 36 is then dispensed from a second
dispenser 34 into the second annular cavity 28, as shown in FIG. 4.
The first and second plastisol materials 32 and 36 are different
formulations than one another providing different durometers when
cured. The first plastisol material 32 is more flexible than the
second plastisol material 36. The first plastisol material 32 is
suitable for use as a gasket, and the second plastisol material 36
is rigid when cured providing a suitable end disc. An integrated
end disc and gasket is provided by the first and second plastisol
materials 32 and 36 as a result of the curing process.
[0022] The formulations of the first and second plastisol materials
32 and 36 are such to minimize wet blending, which is a condition
during which the materials intermix with one another. It is
desirable to retain the first and second plastisol materials 32 and
36 within the volumes provided by the respective first and second
cavities 26 and 28. It is also desirable that the rigid second
plastisol material 36 extends from the inner peripheral surface 27
to the outer peripheral surface 29 to provide sufficient support
for the edge 21 of the filter media 18 (see FIG. 1). Arranging the
first plastisol material 32 radially inboard of the second
plastisol material 36, as in the prior art, encourages the first
and second plastisol materials 32 and 36 to blend with one another,
which is undesirable.
[0023] A filter media 38 having an edge 21 is embedded into the
second plastisol material 36 (as shown in FIG. 5). The mold 24
containing the first and second plastisol materials 32 and 36 along
with the filter media 38 enters an oven 40 to cure the first and
second plastisol materials 32 and 36.
[0024] Subsequent to completing the curing process shown in FIG. 5,
another mold is filled with the first and second plastisol
materials 32 and 36, as described above. An opposite edge of the
filter media 38 is embedded into the newly filled mold. The newly
filled mold and filter media 38 along with the already cured first
and second plastisol materials 32 and 36 again enter the oven 40. A
completed filter cartridge 46 is provided, as shown in FIG. 6.
Alternatively, it may be desirable to provide a rigid end disc at
the opposite edge of the filter media 38 to cover an opening 49
provided by the filter media 38. To form such a filter cartridge,
the opposite edge of the filter media 38 is embedded in a mold
filled with the rigid, second plastisol material 36. The first
plastisol material 32 is unnecessary since the end of the filter
media 38 is closed by the rigid end disc.
[0025] The inventive method provides integrated end discs 42 and
gaskets 44. The end discs 42, which are provided by the second
plastisol material 36, have inner and outer circumferential
surfaces 48 and 50. The inner circumferential surfaces 48 provide
the opening 49 that is aligned with an opening provided by the
filter media 38. The end discs 42 include first and second surfaces
52 and 54 that are respectively defined by first and second planes
P1 and P2. The edges 21 of the filter media 38 extend through the
first surfaces 52 into the second plastisol material 36. The
gaskets 44 extend axially away from the second surfaces 54 in a
direction opposite the edge 21. In the embodiment shown in FIG. 6,
the gaskets 44 are arranged radially outward of the inner
circumferential surfaces 48 of the end discs 42.
[0026] Although a preferred embodiment of this invention has been
disclosed, a worker of ordinary skill in this art would recognize
that certain modifications would come within the scope of this
invention. For that reason, the following claims should be studied
to determine the true scope and content of this invention.
* * * * *