USRE36129E

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Info

Publication number: USRE36129E
Application number: US08/638,906
Authority: US
Inventors: Ernesto Buonpastore
Original assignee: Dana Inc
Current assignee: Mann and Hummel Filtration Technology US LLC
Priority date: 1992-07-08
Filing date: 1996-04-24
Publication date: 1999-03-09
Anticipated expiration: 2012-07-08

Abstract

An air filter assembly . .comprises.!. .Iadd.includes .Iaddend.a filter housing having a filter media . .is.!. mounted therein, and interposed between the inlet and outlet of the housing. An end cap having an annular groove formed therein is mounted to one end of the filter media. A gasket formed of a pliable material is mounted within the groove. The assembly is provided with . .means.!. .Iadd.a nut and bolt assembly .Iaddend.for urging the end cap against an adjacent end wall of the housing to compress the pliable gasket therebetween, thereby sealing the inlet from the outlet, and insuring that air passing through the outlet must first pass through the filter media of the filter unit.

Description

.Iadd.This application is a continuation of Ser. No. 08/086,047, filed Jun. 30, 1993, now abandoned, which is a reissue of Ser. No. 07/910,415, filed on Jul. 8, 1992, now U.S. Pat. No. 5,207,811. .Iaddend.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to air filters and, more particularly, to heavy duty air filters including a gasket mounted thereon to prevent the flow of unfiltered air about the filter.

2. Summary of Related Art

Air filters are well known devices wherein air is drawn or forced into a housing and caused to pass through a filter unit having a full flow filter media to remove the dirt and dust particles carried in the air. Substantially clean air is thereby passed to the point of usage, such as an internal combustion engine. Large, heavy duty air filters are utilized on heavy equipment, such as trucks and earth movers. Such air filters have heretofore generally included an annular foamed rubber gasket bonded to the substantially flat end cap of the filter unit with an adhesive. The gasket seals the inlet from the outlet of the housing, so that no air will pass through the outlet without first having passed through the filter unit. Typically, the gasket is compressed between the end cap of the filter unit and the end wall of the housing by the manual tightening of a bolt which urges the filter unit into sealing engagement against the end wall of the housing.

While the mounting of the foamed rubber gasket to the end cap by means of an adhesive is almost universally practiced, and has been for many years, this construction has a number of disadvantages, the significance of which were not heretofore appreciated. Thus, the gasket, which in air filters is generally formed of a foamed rubber material, tends to lose its stability and concentricity as the filter unit is forced against the housing end wall. Further, it is believed that users often overtighten the bolt, thereby subjecting the gasket to excessive compressive forces and potentially causing permanent deformation of the gasket. As a result, the integrity of the seal provided by the gasket is often compromised. Finally, the bonding of the gasket to the housing end cap makes it difficult if not impossible to remove and replace the gasket. Replaceability of the gasket is desirable if, for example, the filter unit is of the type which is cleaned and reused.

SUMMARY OF THE INVENTION

The present invention relates to an air filter assembly comprising a filter housing having opposing end walls and a side wall between the end walls. The housing has an air inlet and an air outlet formed therein. A filter media is mounted within the housing and is interposed between the inlet and outlet of the housing. An end cap is mounted to one end of the filter media, the end cap having an annular groove formed therein. A gasket formed of a resilient, pliable material is mounted within the groove. The assembly is provided with means for urging the end cap against an adjacent end wall of the housing to compress the pliable gasket therebetween, thereby sealing the inlet from the outlet so that no air can pass out of the outlet without having first passed through the filter media.

The novel construction of the present invention is advantageous in that the side walls of the groove protect the gasket from sliding and collapsing, ensuring the stability and concentricity of the gasket. Furthermore, the walls defining the groove serve to limit the amount of potentially damaging compressive force which may be applied to the gasket through the manual tightening of the bolt. As the gasket is retained with a groove, the need to use an adhesive to permanently bond the gasket to the end cap is eliminated, facilitating replacement of the gasket.

While somewhat similar grooves have been used in conjunction with the sealing gasket on spin-on oil filters for many years, there are many important distinctions between oil filters and air filters which presumably have not led others to employ a structure similar to the present invention on air filters. Such distinctions include the widely differing temperature and pressure conditions experienced by oil filters and air filters. Oil filters typically operate at much higher temperatures and pressures than do air filters. Thus, the gaskets for oil filters are generally formed of a rigid, relatively hard rubber material, while the gaskets for air filters are formed of a resilient, pliable foamed rubber material. Air filter gaskets are thus much more susceptible to deformation and loss of concentricity than are oil filter gaskets. In view of the different environments, the advantages of the present invention were not heretofore appreciated.

BRIEF DESCRIPTION OF THE DRAWINGS

The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:

FIG. 1 is a longitudinal sectional view of the an air filter in accordance with the present invention;

FIG. 2 is an enlarged view of a portion of the air filter of FIG. 1 after tightening;

FIG. 3 is an enlarged sectional view of one embodiment of the housing end cap and gasket of the present invention;

FIG. 4 is an enlarged sectional view of a second embodiment of the housing end cap and gasket;

FIG. 5 is an enlarged sectional view of a third embodiment of the housing end cap and gasket;

FIG. 6 is an end view of a fourth embodiment of the housing end cap and gasket; and

FIG. 7 is an enlarged sectional view taken alongline 7--7 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, there is illustrated in FIG. 1 an air filter assembly in accordance with the present invention including a housing generally designated 10 having a filter unit generally designated 12 mounted therein. Thehousing 10 is formed of anupper portion 14 and alower portion 16 which are held together by any appropriate means, such as by aclamping ring 18. Theside wall 20 of theupper portion 14 is provided with aninlet 22 near the top thereof, and the top orend wall 24 of thehousing 10 is provided with anoutlet 26. The bottom of the housing is closed by abottom wall 28.

Thefilter unit 12 is comprised of afilter media 30 which is typically made of pleated paper which may or may not be treated with a moisture resistant material. The pleatedpaper filter media 30 is protected byinner tube 32 andouter tube 34, both formed of a foraminous material, such as perforated metal.

Thefilter unit 12 is further provided with anend cap 36, typically formed of a suitable metal, at the lower end thereof. Theend cap 36 has anouter flange 38 which abuts the lower end of theouter tube 34 and aninner flange 40 which abuts the lower end of theinner tube 32 to retain theouter tube 34,inner tube 32 andfilter media 30 in position. The inner portion of theend cap 36 extends upwardly and inwardly to form a dome-like structure 42 within theinner tube 32. This dome-like structure 42 is provided with a substantiallyfat center portion 44 having anopening 46 therein. Aspider 48 is mounted at theoutlet 26, extending downwardly and inwardly therefrom to fixedly engage the end of abolt 50 which extends through theopening 46. Thebolt 50 is provided with an associatedwing nut 52 and sealingwasher 54, with thewasher 54 engaging theflat center portion 44 of theend cap 36 to retain thefilter unit 12 in position within thehousing 10.

As best seen in FIG. 2 the upper end of thefilter unit 12 is likewise provided with anend cap 56, also typically formed of a suitable metal. Theend cap 56 includes anouter flange 58 which abuts the upper end of theouter tube 34, and aninner flange 60 which abuts the upper end of theinner tube 32. Theupper end cap 56 is sealed to the upper end of the pleatedpaper filter media 30 by any suitable means such as by means of an adhesive.

Agasket 62 formed of a suitable pliable material preferably foamed rubber, is mounted in agroove 64 formed in theend cap 56. Thegroove 64 is preferably formed by providing a pair of radially spacedannular projections 66 extending from theend cap 56 away from thefilter media 30. The base of thegroove 64 thus remains coplanar with the remainder of theend cap 56, abutting the end of thefilter media 30. Theend cap 56 may be formed on a stamping press from a single sheet of metal by employing various dies to form theend cap 56 andgroove 64.

Thegasket 62 is compressed between theend cap 56 of thefilter unit 12 and thetop wall 24 of thehousing 10 by tightening thewing nut 52 on thebolt 50, which forces thefilter unit 12 against thetop wall 24 of thehousing 10. Thegasket 62 thus provides a seal between theupper end cap 56 and theend wall 24 of thehousing 10, thereby sealing theinlet 22 to thehousing 10 from theoutlet 26 and insuring that air passing through theoutlet 26 must first pass through thefilter media 30 of thefilter unit 12.

Theprojections 66 forming thegroove 64 support thegasket 62 laterally and prevent it from sliding and collapsing upon tightening of thewing nut 52 on thebolt 50, thereby ensuring the stability of thegasket 62. Retaining thegasket 62 in theconcentric groove 64 also virtually eliminates any loss of concentricity which would otherwise be experienced by thegasket 62 during use of the filter assembly.

When properly tightened, thegasket 62 is generally compressed from about 20 to 25 percent. However overtightening is not uncommon, and potentially results in permanent deformation of thegasket 62. The tightening of thewing nut 52 on thebolt 50 urges thefilter unit 12 towards thetop wall 24 of thehousing 10, compressing thegasket 62 between theend cap 56 of thefilter unit 12 and thetop wall 24 of thehousing 10. Theprojections 66 forming thegroove 64 serve to limit the amount of potentially damaging compressive force which may be applied to thegasket 62 through the manual tightening of thebolt 50. No additional compressive force is applied to thegasket 62 once theprojections 66 contact thetop wall 24 of thehousing 10. Thus, the height of theprojections 66 controls the extent to which thegasket 62 may, at a maximum, be compressed.

Furthermore, while FIG. I shows the air filter mounted vertically, in some applications the space available requires that the filter be mounted horizontally. In such applications, the weight of thefilter unit 12 tends to cause the outer end of the unit to sag. With the prior art filter gaskets, this subjected the bottom portion of the gasket to additional compressive forces while reducing the compressive force against the upper portion of the gasket to the point where the seal was not effective. User response was typically to further tighten the wing nut on the bolt, often resulting in failure of the gasket. With the present invention, theprojections 66 contact thetop wall 24, providing rigidity and preventing any gravity induced sagging of thefilter unit 12 about thebolt 50, thereby eliminating the problems associated with mounting the prior an filters horizontally.

As thegasket 62 is retained withingroove 64, the need for an adhesive to permanently bond thegasket 62 to theend cap 56 is eliminated, greatly enhancing the replaceability of thegasket 62. Preferably, a means is provided for retaining thegasket 62 within the groove

In one embodiment of the invention, illustrated in FIG. 3, a gasket 62' is retained within the groove by angling the inner wall of each of the projections 66' towards the center of the groove. In this embodiment, the gasket 62' is preferably provided with a bevel cut so that the gasket 62' tapers away from, the end cap 56'. The pliable gasket 62' is compressed and inserted into the groove, where the gasket 62' expands to meet the inner walls of the projections 66'. The gasket 62' is thus retained within the groove by frictional forces.

In the alternate embodiment illustrated in FIG. 4, the gasket . .62.!. .Iadd.62" .Iaddend.is retained within thegroove 64 by forming the gasket . .62.!. .Iadd.62" .Iaddend.so at its inner diameter is somewhat less than the inner diameter of thegroove 64. The gasket . .62.!. .Iadd.62" .Iaddend.must be stretched outwardly to allow insertion of the same into thegroove 64. The gasket . .62.!. .Iadd.62" .Iaddend.thus exerts a force on the inner wall of theinner projection 66, retaining the gasket . .62.!. .Iadd.62" .Iaddend.within thegroove 64.

Similarly, in a third embodiment illustrated in FIG. 5, the gasket . .62.!. .Iadd.62" .Iaddend.is retained within thegroove 64 by forming the gasket . .62.!. .Iadd.62" .Iaddend.so that its outer diameter is somewhat greater than the outer diameter of thegroove 64. The gasket . .62.!. .Iadd.62" .Iaddend.must be compressed inwardly to allow insertion of the same into thegroove 64. The gasket . .62.!. .Iadd.62" .Iaddend.exerts a force on the inner wall of theouter projection 66, retaining the gasket . .62.!. .Iadd.62" .Iaddend.within thegroove 64.

In the most preferred embodiment, illustrated in FIGS. 6 and 7, the groove is provided with a plurality of altering inwardly-projectingindentations 68 formed on the opposing inner walls of theprojections 66" forming the groove. The plurality ofindentations 68 frictionally retains thegasket 62 within the groove. Theindentations 68 also facilitate insertion of thegasket 62 into the groove .Iadd.in theend cap 56" .Iaddend.by allowing the air beneath thegasket 62 to escape as thegasket 62 is inserted into the groove. Theindentations 68 are preferably struck from the side walls of theprojections 66".

In accordance with the provisions of the patent statues, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.

Claims

What is claimed is:

1. An air filter assembly, comprising:

a filter housing having opposing end walls and a side wall between the end walls said housing having an air inlet and an air outlet formed therein;

a filter media mounted within said housing and interposed between the inlet and outlet of said housing;

a metal end cap secured to one end of said filter media, said end cap having a pair of radially spaced annular projections extending from said end cap to form an annular groove in said metal end cap, each of said projections being comprised of a pair of opposed sidewalls interconnected at the distal ends thereof;

a gasket disposed within said groove, said gasket being formed of a pliable material; and

means for urging said end cap against an adjacent end wall of said housing to compress said gasket therebetween, thereby scaling said inlet from said outlet and insuring that air passing through said outlet must first pass through said filter media.

2. An air filter assembly as defined in claim 1, wherein said gasket is formed of foamed rubber.

3. An air filter assembly as defined in claim 1, wherein each of said projections is comprised of a pair of opposed sidewalls stamped from said metal end cap.

4. An air filter assembly as defined in claim 1, wherein each of said projections is formed of an inner sidewall adjacent said groove and an associated outer sidewall spaced radially therefrom, both of said outer sidewalls being angularly disposed with respect to the inner sidewall associated therewith.

5. An air filter assembly as defined in claim 1, further comprising means for retaining said gasket within said groove.

6. An air filter assembly as defined in claim 5, wherein said means for retaining said gasket within said groove comprises a plurality of alternating inwardly-projecting indentations provided on the opposing inner walls of the groove.

7. An air filter assembly as defined in claim 1, wherein the inner diameter of said gasket is less than the inner diameter of said groove.

8. An air filter assembly as defined in claim 1, wherein the outer diameter of said gasket is greater than the outer diameter of said groove.

9. An air filter assembly as defined in claim 1, wherein the inner walls defining sad groove are angled inwardly toward the center of said groove.

10. An air filter assembly as defined in claim 9, wherein the opposing side walls of said gasket are provided with a bevel cut so that the gasket tapers inwardly away from said end cap.

11. An air filter assembly, comprising:

a filter housing having opposing end walls and a side wall between the end walls, said housing having an air inlet and an air outlet formed therein;

an end cap secured to one end of said filter media, said end cap having a groove formed therein by a pair of radially spaced annular projections extending from said end cap, each of said projections being comprised of a pair of opposed sidewalls stamped from said . .metal.!. end cap;

a pliable, foamed rubber gasket disposed within said groove; and

means for urging said end cap against an adjacent end wall of said housing to compress said gasket therebetween, thereby sealing said inlet from said outlet so that no air can pass out of said outlet without having first passed through said filter media.

12. An air filter assembly as defined in claim 11, wherein said groove is provided with of a plurality of alternating inwardly-projecting indentations provided on the opposing inner walls of the groove for retaining said gasket within said groove.

13. An air filter assembly as defined in claim 11, wherein the inner diameter of said gasket is smaller than the inner diameter of said groove.

14. An air filter assembly as defined in claim 11, wherein the outer diameter of said gasket is larger than the outer diameter of said groove.

15. An air filter assembly as defined in claim 11, wherein the opposing inner walls of said annular projections are angled inwardly toward the center of said groove.

16. An air filter assembly as defined in claim 15, wherein said gasket is provided with a bevel cut so that the gasket tapers away from said end cap.

17. An air filter assembly as defined in claim 11, wherein each of said projections is formed of an inner sidewall adjacent said groove and an associated outer sidewall spaced radially therefrom, both of said outer sidewalls being angularly disposed with respect to the inner sidewall associated therewith. .Iadd.

18. An air filter comprising:

a filter element;

a metal end cap secured to one end of said filter element, said end cap having a pair of radially spaced annular projections extending therefrom to form an annular groove in said end cap, each of said projections being comprised of a pair of opposed sidewalls interconnected at the distal ends thereof; and

a gasket disposed within said groove, said gasket being formed of a pliable material. .Iaddend..Iadd.19. An air filter as defined in claim 18, wherein each of said projections is comprised of a pair of opposed sidewalls stamped from said metal end cap. .Iaddend..Iadd.20. An air filter as defined in claim 18, wherein each of said projections is formed of an inner sidewall adjacent said groove and an associated outer sidewall spaced radially therefrom, both of said outer sidewalls being angularly disposed with respect to the inner sidewall associated therewith. .Iaddend..Iadd.21. An air filter as defined in claim 18, wherein said gasket is formed of foamed rubber. .Iaddend..Iadd.22. An air filter as defined in claim 18, further comprising means for retaining said gasket within said groove. .Iaddend..Iadd.23. An air filter as defined in claim 22, wherein said means for retaining said gasket within said groove comprises a plurality of alternating inwardly-projecting indentations provided on the opposing inner walls of said groove. .Iaddend..Iadd.24. An air filter as defined in claim 18, wherein the inner diameter of said

gasket is less than the inner diameter of said groove. .Iaddend..Iadd.25. An air filter as defined in claim 18, wherein the outer diameter of said gasket is greater than the outer diameter of said groove. .Iaddend..Iadd.26. An air filter as defined in claim 18, wherein the inner walls defining said groove are angled inwardly toward the center of said groove. .Iaddend..Iadd.27. An air filter as defined in claim 18, wherein the opposing side walls of said gasket are provided with a bevel cut so that the gasket tapers inwardly away from said end cap. .Iaddend..Iadd.28. A filter unit for an air filter assembly comprising:

a filter media having an end;

an end cap secured to said end of said filter media, said end cap including a pair of radially spaced annular projections formed thereon having respective inwardly facing sidewalls which define an annular groove therebetween; and

a gasket formed from a pliable material disposed within said groove. .Iaddend..Iadd.29. A filter unit as defined in claim 28, wherein said end cap is formed from metal, and wherein said projections are stamped from said metal end cap. .Iaddend..Iadd.30. A filter unit as defined in claim 28, wherein each of said sidewalls is an inner sidewall, and wherein each of said projections further includes an outer sidewall spaced radially from said respective inner sidewall. .Iaddend..Iadd.31. A filter unit as defined in claim 30, wherein each of said outer sidewalls is angularly disposed with respect to said respective inner sidewalls.

a radial distance defined between said outer edges. .Iaddend..Iadd.40. A filter unit as defined in claim 28, wherein said gasket defines a pair of radially spaced sidewalls which extend from respective inner edges adjacent said end of said filter media to respective outer edges, and wherein a radial distance defined between said inner edges is equal to a radial distance defined between said outer edges. .Iaddend..Iadd.41. A filter unit as defined in claim 28, wherein said gasket defines a pair of radially spaced sidewalls which extend from respective inner edges adjacent said end of said filter media to respective outer edges, and wherein a radial distance defined between said inner edges is greater than a radial distance defined between said outer edges. .Iaddend..Iadd.42. A filter unit as defined in claim 28, wherein said inner walls extend from respective inner edges adjacent said end of said filter media to respective outer edges, and wherein said inner edges are connected together. .Iaddend.