Abstract:
An oil filter gasket includes a body and a flap extending inwardly from the body away from a recess of an oil filter housing. The body provides a compression fitting between the oil filter and a mounting structure. The flap also provides a compression fitting between the oil filter and mounting structure. As oil pressure within the oil filter increases, the flap is further forced into engagement with the mounting structure thereby increasing the oil pressure that the oil filter may be subjected to before leaking.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates to a fluid filter such as an oil filter, and more particularly, the invention relates to a gasket for fluid filters.  
         [0002]     A spin-on type oil filter typically includes a housing containing the filtering components. The housing typically includes a case bottom assembly that comprises a tapping plate and a retainer that gets seamed to a can of the housing during manufacture of the filter. The retainer includes a recess or seat that receives a gasket. The gasket engages the mounting structure to which the oil filter is attached, such as an engine block or a remote oil filter adapter.  
         [0003]     The tapping plate includes a threaded hole. The filter is secured to the mounting structure using the threaded hole. The elastomeric gasket is compressed during installation of the filter onto the mounting structure, which retains the oil within the filter and mounting structure during normal operation.  
         [0004]     As the engine RPM increases, the oil pressure inside the filter also increases. The increased pressure within the filter can cause the housing to swell and the case bottom assembly to deflect downwardly near the periphery of the filter and away from the mounting structure. As the case bottom assembly deflects downward, the compression of the gasket is reduced thereby compromising the seal between the filter and mounting structure. As a result, oil may leak past the gasket under the increased oil pressure.  
         [0005]     Gaskets have employed various cross-sections to enhance the seal of the gasket against the mounting structure under pressure. For example, square, round, oval, D-shaped, double D-shaped, P-shaped, and other shapes have been used. Nonetheless, gasket leaks have still been problematic under high oil pressure. This is of increasing concern since modern oil filters must withstand higher oil pressures due to the increased power of the engines.  
         [0006]     Other oil filters have employed tapping plates of increased thickness to reduce the deflection of the case bottom assembly. Still other oil filters have reduced the gasket diameter, increased the gasket hardness, or employed metal rings into the gasket to enhance the sealing of the gasket under higher pressures. These solutions have resulted in increased material cost and/or increased tooling cost.  
         [0007]     Therefore, what is needed is an improved oil filter gasket and high oil pressure applications while avoiding increased material or tooling cost.  
       SUMMARY OF THE INVENTION AND ADVANTAGES  
       [0008]     The present invention provides a fluid filter including a housing having a can with an open end. A tapping plate is arranged at the open end and includes multiple fluid apertures arranged circumferentially around a portion of the tapping plate, which fluidly communicate with fluid passages in the mounting structure. A retainer is secured to the can adjacent to the tapping plate for retaining the tapping plate and filter the components within the housing. The retainer includes an annular recess or seat arranged outwardly of the fluid apertures.  
         [0009]     The inventive gasket is seated in the angular recess. The gasket includes a body with a flap extending inwardly from the body and away from the recess. In an example embodiment, the gasket includes a groove arranged between the body and the flap. The body may have a generally quadrangular cross-section.  
         [0010]     The housing is secured to a mounting structure having a threaded stud. The threaded hole of the aperture is fastened to the threaded stud. The mounting structure includes a sealing surface which the gasket engages when the filter is in the installed position. The body of the gasket provides a compression fitting. The flap engages the surface and provides a compression fitting under a first force. Pressurized oil within the filter further biases the flap into an engagement with the surface providing a second force to enhance the seal of the gasket between the mounting structure and the filter. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     Other advantages of the present invention can be understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:  
         [0012]      FIG. 1  is a cross-sectional view of the inventive filter prior to installation onto the mounting structure;  
         [0013]      FIG. 2  is a cross-sectional view of the filter installed onto the mounting structure with the inventive gasket in a compressed state; and  
         [0014]      FIG. 3  is an enlarged cross-sectional view of the inventive gasket shown in  FIG. 2 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]     A fluid filter  10  is shown in  FIG. 1 . The filter  10  shown is suitable for use as a vehicle oil filter, however, this invention may be used in any fluid filter application. The filter  10  comprises a housing  12  including a can  14  with a retainer  16  secured to the open end  15  of the can  14 . The housing  12  also includes a tapping plate  18  typically arranged interiorly and adjacent to the retainer  14 .  
         [0016]     The retainer  16  and tapping plate  18  provide what is typically referred to as the case bottom assembly  17 . The tapping plate  18  includes a central threaded hole  20 . The filter  10  is secured to a mounting structure  22  such as an engine block or remote oil filter adaptor having fluid passages that carry the fluid to and from a desired location such as a vehicle engine. The mounting structure  22  includes a threaded stud  24  that threadingly engages the threaded hole  20  of the tapping plate  18  when the filter  10  is in the installed position. While the tapping plate  18  is typically used to secure the filter  10  to the mounting structure  22 , it should be understood that other securing configurations may also be used. For example, a threaded fastener may be passed through a hole in the length of the filter  10  and received in a threaded hole of the mounting structure  22  to clamp the filter  10  to the mounting structure  22 . Alternatively, a spring clamp or screw clamp may engage the housing  12  and force the filter  10  into engagement with the mounting structure.  
         [0017]     A filter assembly  26  is arranged within the housing  12 . The filter assembly  26  includes end disks  30  having a filter media  28 , such as a paper filter element, arranged between the end disk  30  in any suitable manner, which is well known in the art. The filter media  28  may define a central opening. Typically, the filter media  28  is a pleated paper element. A spring or guide  36  is arranged between the filter assembly  2618  and the housing  12  to position the filter assembly  26  in a desired manner during assembly of the filter  10 . The filter assembly  26  is positioned longitudinally within the housing  12  by a spring  36 . The spring  36  biases the filter components toward the retainer  16 .  
         [0018]     The filter  10  has an inlet side  32  on one side of the filter media  28  and an outlet side  34  on the opposite side of the filter media  28 . For the arrangement shown, the inlet side  32  corresponds to the outside of the filter assembly  26 , and the outlet side  34  corresponds to the inside or central opening of the filter media  28 . The retainer  16  and tapping plate  18  include apertures  41  to permit fluid to flow from the structure  22  supporting the filter  10  to the inlet side  32 . During normal operation, the fluid flows through the filter media  28  to the central opening, which corresponds to the outlet side  34 , to remove debris from the fluid. Fluid then flows through the central opening and exits through the threaded hole  20  back through the structure  22  supporting the filter  10 . However, it is to be understood that the fluid flow may be other than described above depending upon the application and customer specifications.  
         [0019]     The filter  10  includes an anti drain back valve  38  permitting fluid to flow through the apertures  41  to the inlet side  32  of the filter  10 . Multiple apertures  41  are typically arranged circumferentially about a portion of the tapping plate  18 . The anti drain back valve  38  prevents fluid flowing from the inlet side  32  back into the mounting structure  22 . The filter  10  may also include a relief valve  40  in one of the end disks  30  that opens and permits fluid flow to bypass the filter assembly  26  under high oil differential pressure and flow directly to the outlet side  34  without passing through the filter media  28 .  
         [0020]     Referring to  FIGS. 2 and 3 , the retainer  16  may include an annular recess  42  or seat radially outward of the apertures for receiving the inventive gasket  44 . The shape of the annular recess  42  and gasket  44  may be of any suitable shape, but is preferably circular from a top view. The gasket  44  provides a seal between a surface  46  of the mounting structure  22  and the filter  10 . The gasket  44  includes a body  48  with a flap  50  extending inwardly and upwardly away from the recess  42 . The flap  50  may be proximate to the apertures  41 .  
         [0021]     The cross-section of the gasket  44  may be of any shape. For the example shown, the body  48  is a generally quadrangular cross-section with the flap  50  extending from a corner of the body  48 . Referring to  FIGS. 1 and 3 , the inventive gasket  44  may include a groove  49  or notch arranged between the flap  50  and body  48  to increase the flexibility of the flap  50  relative to the body  48 . The groove  49  creates a cavity  52  between the gasket  44  and the surface  46 .  
         [0022]     The body  48  includes an upper surface  51  that engages the surface  46  of the mounting structure  22  under compression to provide a primary seal. The flap  50  also engages the surface  46 , for example, in the embodiment shown at a corner  53  of the surface  46 . The flap  50  engages the corner  53  under a compression applying a first force. When the filter  10  contains pressurized oil, a second force is generated on the flap biasing the flap into engagement with the corner  53  to provide an enhanced seal to that of the compression seal provided by the body. As the case bottom assembly  17  deflects at its periphery  54 , the flap  50  will continue to provide an adequate seal to prevent leakage past the gasket  44 . In one example, the inventive flap  50  may enable the oil pressure be increased by 16 psi prior to leakage of oil past the gasket  44 .  
         [0023]     The gasket  44  includes spaced apart upper  51  and lower  55  surfaces on the body  48 . The surfaces  51 ,  55  lie in opposing planes. Another surface  57  adjoins the surfaces  51 ,  55 . The flap  50  extends inwardly from the body  48  away from one of the opposing planes and the surface  57 . The flap  50  extends beyond the other opposing plane in an uncompressed state, which is best shown in  FIG. 1 . In a compressed state, which is best shown in  FIG. 3 , the flap  50  may extend only slightly beyond the plane of the upper surface  51  or not at all.  
         [0024]     The invention has been described in an illustrative manner, and it is to be understood that the terminology that has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.