Abstract:
An air filter element includes an annular filter media having an end cap with an elongated sleeve portion having a unitary array of canted fins and a unitary annular disk partially closing one end. The end cap is preferably made of high impact polypropylene. An annular gasket made of foam rubber or polyurethane is adhered to the unitary annular disk portion, preferably by a two shot molding step.

Description:
FIELD OF THE INVENTION 
     The present invention relates to fluid filter elements with fin arrays. More particularly, the present invention relates to fluid filter components with fin arrays wherein the fin arrays are in association with an end cap. 
     BACKGROUND OF THE INVENTION 
     Fluid filters are widely used in machinery, such as but not limited to internal combustion engines, for filtering various fluids. It has been found that it is highly desirable to provide an even flow distribution of particles into filter media, which increases the filter media capacity and the life of a filter media while reducing the space consumed by the filter media. One way to address this is to provide, annular filter elements having an array of fins which encourage mixing of contaminated inlet air in order to promote an increase in capacity and efficiency. 
     In providing annular filters with fin arrays, there is a need to improve production efficiencies while providing improvements to consumers. There is also a constant need to maintain reliability while improving production efficiency. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention a fluid filter includes an annular filter media adapted for enclosure in a housing having a fluid inlet and a fluid outlet. The annular filter media has a first end and a second end, as well an outer dirty side surface and an inner clean side surface. The first end cap has an annular sleeve portion with the first and second ends. The annular sleeve portion and the second end both have an inside diameter which complements the outside diameter of the annular filter media. The first end portion is partially enclosed by a radially extending annular end cap portion having a width substantially the same as that of the first end of the filter media, which first end of the filter media is within the sleeve and covers the first end of the filter media. An array of fins extends radially outward from the sleeve, the fins being of the same polymer material as, and being unitary with the sleeve. An annular sealing gasket of a compressible or flexible material is molded to the annular disk and extends in the direction of the axis of the annular filter media. In a further aspect of the invention, the annular sealing gasket is made of foam rubber or silicon while the annular sleeve portion and an array of fins are molded of polypropylene copolymer. 
     In still a further aspect of the invention the filter element is used as an air filter element for internal combustion engines. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various other features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
         FIG. 1  is a side perspective view partially in elevation of a filter element configured in accordance with the present invention disposed within a filter housing; 
         FIG. 2  is a partial elevation of the filter element of  FIG. 1 ; 
         FIG. 3  is a side view with portions illustrated in phantom of filter element end cap used with the filter element shown in  FIGS. 1 and 2 ; 
         FIG. 4  is a first end view of the end cap of  FIG. 3 ; 
         FIG. 5  is enlarged elevation of a portion of an end cap shown in  FIGS. 3 and 4 , and 
         FIG. 6  is a second end view a of closed end cap closing the filter element of  FIGS. 1 and 2 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIG. 1  there is shown filter housing  10  which houses a filter element  12  configured in accordance with the principles of the present invention. The filter housing  10  includes an air inlet  14  and an air outlet  16 . Filter element  12  is disposed between the air inlet  14  and air outlet  16  and removes particulate matter from inlet air so that when the inlet air is used as combustion air for an internal combustion engine, the particulates are not introduced into the engine where they can damage the engine. The air inlet  14  is disposed adjacent to a first end  18  of the filter element  12  and is drawn through the filter element by low pressure at the engine outlet  16 . The filter element  12  is supported within the housing  10  and has a sealed engagement with the outlet  16  in the direction of axis  20 . 
     At a second end  22  of the filter element  12 , a housing lid  24  is retained on a threaded stud  25  by a nut  26 . A washer  27  which is coaxial with the threaded stud  25 , exerts an axial force between the lid  24  and second end  22  of the filter element  12  to hold the first end  18  of the filter element sealed around the outlet opening  16 . 
     Referring now to  FIG. 2  in combination with  FIG. 1 , it is seen that the filter element  12  is comprised of an annular filter media  30 , preferably in the form of pleated filter paper. The annular filter media  30  is covered on the outside by a perforated outer sleeve  32  that has holes  34  therethrough so that dirty outside air passes through the perforated outer sleeve into the annular pleated filter media. The outer sleeve  32  can also be expanded metal, or optionally, not used at all. The annular filter media  30  defines a hollow core  36  which is lined with an inner spiral tube  38  having holes  39  therethrough allowing filtered clean air to enter the hollow core. Rather than an inner spiral tube  38 , a perforated inner sleeve or expanded metal inner sleeve may be employed. Optionally, no inner tube or sleeve is used. The outer sleeve  32  and inner spiral tube  38  cooperate to provide a relatively rigid support for the pleated paper media  30 . 
     The filter media  30  is closed at a first annular end  44  by a first, annular end cap  46  and at a second annular end  48  by second annular end cap  50 . The second annular end cap  50  completely closes one end of the hollow core  36  and has an indentation  52  (see  FIG. 6 ) therein in which the washer  27  is seated to hold the filter element  12  against the end of the filter housing  10  around the circular outlet opening  16  (see  FIG. 1 ) this is accomplished by using another nut  26 . 
     As is seen in  FIGS. 3 and 4 , the first end cap  46  is a single piece comprising sleeve portion  60  of an axial length which is a substantial portion of the axial length of the annular filter element  30  in the direction of axis  20 . For example, the sleeve portion  60  has an axial length of about 3 to about 4 inches while the filter element has an axial length of about 11 inches. The sleeve portion  60  has first end  62  disposed adjacent the first end  44  of the annular filter media  30  when the first end cap  46  is slid over the annular filter media and a second end  64  which has an inner diameter that complements the outer diameter of the inside surface of the perforated metal sleeve  32  ( FIG. 2 ), so that the sleeve portion  60  fits snugly over the filter media  30 . Unitary with the end cap  46 , is a fin array  68  comprising a plurality of canted fins  70 . The array  68  of fins  70  is axially spaced from the first end  62  of the first end cap  46  at the second end  64  thereof. Preferably, the sleeve portion  60  and fin array  68  are molded from polypropylene, or another plastic material such as a polyamide material (NYLON®), to form the unitary sleeve portion  46  which includes the fin array  68 . 
     Integral with the sleeve portion  60  and the fin array  68  is an annular end disk portion  75 . The annular disk portion  75  has an inner surface  76  and an exterior surface  77 . Projecting inwardly from the inner surface  76  is an annular lip  79  that defines an opening  80  that is aligned with the air outlet opening  16  of the housing  10  when the filter element  12  is mounted in the housing. The lip  79  extends over a short inner portion of the filter media  30  and inner spiral tube  38  when the first end cap  46  is mounted over the filter media. A layer of plastisol, or other sealing material such as urethane, is disposed between the bottom surface  76  of the annular disk portion  75  and the first end  44  of filter media  30  in order to adhere and seal the annular disk portion to the first end of the filter media. 
     As seen in  FIG. 5  as well as  FIGS. 1–4 , an annular gasket  85  projects from the outer surface  77  of the annular disk  75  for sealing with the inside of the housing  10  adjacent to the opening  16 . The annular gasket  85  is made of either an open cell foam, such as a foam rubber composition, so as to be compressible, or is made of polyurethane, so as to be flexible. The gasket  85  is either glued to the surface  77  of the annular disk portion  75  or is co-molded therewith using a two shot molding process in which gasket material is shot into the mold onto previously shot material for the sleeve portion  60  and fin array  68 . Alternatively, the material for the gasket  85  is shot first and the material for the sleeve portion  60  and fin array  68  is shot against the molded material of the gasket  85 . In either case, as the shot material cures, the gasket  85  adheres to the surface  77  of the annular disk portion  75  that is unitary or a single piece with the sleeve portion  60 . 
     The sleeve portion  60 , with the unitary fin array  68 , disk  75  and attached gasket  85  are secured as a unitary annular end cap over the perforated outer sleeve  32  with an adhesive such as an epoxy adhesive. 
     From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing form the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.