GB2117663A - Filter gasket - Google Patents

Abstract

A semi-flexible urethane gasket (22) having an annular seal portion (24) sealingly engages the ends of the walls (12, 16) retaining a filter medium. A generally circular retainer plate retains the gasket in place. An annular gripper surface (34) extends inwardly from the seal portion and is spaced above the upper surface of the retainer plate (36). An annular lip (26) extends outwardly from the seal portions (24) to engage with a filter element housing (30). <IMAGE>

Description

SPECIFICATION Gasket This invention relates generally to gaskets and more particularlyto the type of gasket usually referred to as ledge gaskets which are adapted for use with a filter element.

Gaskets of the Iedgetypearealready known from thepriorart. Forexamplein U.S. Patent No. 4,128,251 is disclosed a sealing gasket for an air filter. The gasket, preferably made of plastisol, has a soft base portion that provides a seal between the gasket and thefiltermedium.

In U.S. Patent No.4,056,876 a hot-melt adhesive is used to attach a rim to a filter element. Atight seal is formed when the adhesive is cured.

U.S. Patent No.3,877,910 discloses an air cleaner designed to withstand the impact of an automobile collision. The cleaner has inner and outer casings.

The outer casing gives upon impact, but the inner casing, formed of stronger material, resists. The retainer does notform afiltermedium seal.

U.S. Patent 3,339,516 discloses two moulded vinyl gaskets used to form a seal between the filter element and metal retaining piece.

U.S. Patent2,871,976 discloses a filter element used in an air-cleaner intake silencer. Two end caps, preferably formed of thermoplastic material, are moulded to the ends of a filter medium. These caps form an airtight seal with the filter medium and thus act as gaskets.

U.S. Patent 2,732,031, discloses a seal and gasket combination used in an air filter. A moulded piece is heat-treated and then allowed to cool while in contact with the paper element. The cooled piece acts as a seal and a gasket.

The prior art gaskets and seals proved generally adequate in sealing the end of the filter element itself.

However, a second gasket was needed to provide a water seal between the filter element and the housing into which the element was inserted. That gasket was often fixed to the outer surface of a metal end retainer used to secure the filter element in the housing.

Means was also needed for facilitating removal of a used filter element from the housing. Generally, a metal plate or rim was welded to the metal end retainerforthat purpose. The plate or rim had no sealing function.

The need forthree separate pieces, i.e., a filter element seal, an element-to-housing water seal, and a finger grip for removal, resulted in high manufactur- ing costs and an unreliable and unwieldy product.

It is an object ofthe present invention is to provide a gasket which substantially overcomes many of the problems which exist in the prior art gaskets and seals.

According to the present invention a gasket in or for use in a filter element having an end retainer plate, an inner wall defining an axial cavity, an outerwall concentrically spaced about the inner wall, and a filter medium positioned between the inner and outer walls, the gasket comprises an annular seal portion shaped to extend in use across the space between the inner and outer walls and sealinglyto engage the ends ofthe walls and the retainer plate, an annular lip extending outwardly from the seal portion, and an annular gripper portion extending inwardly from the seal portion, the lower surface of the gripper portion being spaced above the upper surface ofthe retainer plate.

The invention therefore provides an improved seal for a filter element capable of performing several different and distinct functions. The gasket of the invention eliminates the need for a separate elementto-housingwaterseal and aseparatefingergrip ina filter assembly.

The annular seal portion, the annular lip portion, and the annulargripper portions ofthe gasket are preferably formed integrally of semi-flexible urethane material.

In orderthatthe invention may be readily understood one example of a gasket in accordnace therewith and incorporated with a filter element in a sealing mode will now be described with reference to the accompanying drawings. In the drawings.

Figure 1 is a side elevational view, partly in section, of a filter element incorporating the gasket of the present invention; Figure 2 is a sectional detail of a portion of the filter element and gasket shown in Figure 1; Figure 3 is atop plan view ofthefilter element and gasket shown in Figure 1; Figure 4 is a side elevational view, partly in section, of a filter assembly incorporating the gasket of the present invention, and Figure 5 is a sectional detail of a portion ofthefilter assembly and gasket shown in Figure 4.

Referring now to the drawings, a filter element em bodying the features of the present invention is indicated generally by the numeral 10.

Thefilterelement 10 has an inner cylindrical wall 12 which defines an axial cavity 14. An outer cylindrical wall 16 is concentrically spaced about the inner cylidrical wall 12. Both walls 12 and 16 are provided with openings which allow the filtrate to pass through the space between the walls 12 and 16. Preferably, the innerwall 12 is an expanded metal cylinder and the outerwall 16 is a perforated metal cylinder.

Afilter medium 18 is positioned in the space between walls 12 and 16. The filter medium 18 can be any of the conventional filter materials known in the art. Preferably, the filter medium 18 is paper.

The space betweenthewalls 12 and 16 is sealed at both ends of the filter element 10. A conventional plastisol seal 20 is used at one end. The ledge gasket of the present invention, indicated generally by the numeral 22, is used at the opposite end.

The ledge gasket22 has an annularseal portion 24 which sealingly engages the ends ofthe walls 12 and 16. Filte; medium 18 adjacent to those wall ends is also sealingly engaged by the seal portion 24. That configuration prevents unwanted matterfrom enter ing the space between the walls 12 and 16.

An annular lip 26 projects outwardly from the seal portion 24. The space 28 formed between the inner surface of the lip 26 and outer surface of the seal portion 24 is designed to receive the end of a filter element housing 30. The relationship between the lip 26 and the filter element housing 30 is best shown in Figure 5. The lip 26 prevents water and other undesirable elementforseeping into the space between the filter element 10 and the filter element housing 30.

An annularfinger grip 32 extends inwardly from the seal portion 24. The finger grip 32 has a lowersurface 34which is spaced above the upper surface of a metal end retainer36. The space 38 between the finger grip 32 and the retainer 36 is large enough to accommodate a fingertip. With this arrangement, a user can eailyremovethefilterelementfrom its housing 30 by placing his finger on the lowersurface 34 of the finger grip 32 and pulling the filter element 10 toward himself.

The ledge gasket 22 is a moulded unitary element formed of semi-flexible urethane.

The metal end retainer 36 is a generally circular plate used to secure the filter element 10 in the filter element housing 30. The outer edge of the retainer 36 is embedded at42 in the ledge gasket 22. The outer edgeofthe retainer36 has an axial portion 40 which is spaced inwardlyfrom the inner wall 12 and which extends into the ledge gasket 22 and a radial portion 42 which is spaced axiallyfromtheendsofthewalls 12 and 16 and which terminates outwardly about midway between the walls 12 and 16.

When in use, the filter element 10 is customarily secured within a housing 30. A filter element and housing assembly incorporating the features of the present invention is best shown in Figure 4. The housing 30 is a cylindrical case designed to accommodate the filter element 10. A threaded spindle44 mounted in the housing 30 projects through an opening inthe retainer36whenthefilter element 10 is placed in the housing 30. Awing nut 46 is screwed onto the spindle 44 to secure the filter element 10. A user can withdrawthefilter element 10 from the housing 30 by removing the wing nut 46 from the spindle 44, placing his fingertip under the lower surface 34 of the finger grip 32 and pulling the filter element 10 toward himself.

While the invention has been described with reference to a specific embodiment, it will be appreciated that many variations are possible without departing from the scope ofthe invention.

Claims (6)

1. A gasket in orfor use in a filter element having an end retainer plate, an inner wall defining an axial cavity, an outerwall concentrically spaced aboutthe innerwall,and afilter medium positioned between the inner and outerwalls,the gasket comprises an annular seal portion shaped to extend in use across the space between the inner and outerwalls and sealinglytoengagetheendsofthewalls and the retainer plate, an annular lip extending outwardly from the seal portion, and an annular gripper portion extending inwardly from the seal portion, the lower surface of the gripper portion being spaced above the upper surface ofthe retainer plate.

2. A gasket as claimed in claim 1, wherein the annular seal portion, the annular lip and the annular gripper portion are formed of a semi-flexible urethane material.

3. Agasketas claimedinclaimslor2,wherein the annular seal portion, the annular lip and the annular gripper portions are formed integrally.

4. Agasket as claimed in any preceding claim, wherein the annularseal portion isfurthershaped sealingly to engage filter medium adjacent ends of the walls.

5. A gasket substantially as hereinbefore described with reference to the accompanying drawings.

6. A gasket secured to a filter assembly substantially as hereinbefore described with reference to the accompanying drawings.