Abstract:
An oil filter mounting plate assembly formed of two components comprising a plate having a central polygonal opening and a nut having a polygonal periphery configured to be received in the polygonal opening in a press fit including lateral grooves on opposed sides of the nut forming a mechanical interlock with the plate. The nut is internally threaded for threaded securement to the pipe communicating with the oil recirculation system of an internal combustion engine.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a mounting plate for oil filters of the type used for internal combustion engines.  
       BACKGROUND OF THE INVENTION  
       [0002]     Current internal combustion engines are internally lubricated during operation with a recirculating oil system. In order to keep the oil in the recirculating oil system free of particulates that could cause premature wear of engine parts, the oil is further circulated through a filter. In order to maintain the oil as particulate free as possible, the oil filter requires periodic replacement. Thus, oil filters are a disposable commodity which must be mass produced in large quantities at a minimal cost.  
         [0003]     A typical oil filter for an internal combustion engine includes a cup or can-shaped enclosure having a cylindrical side wall, an open end and a closed end. A filtering media or element is received in the enclosure and the open end of the enclosure is then affixed to an oil filter mounting plate generally by crimping. The oil filter mounting plate as presently used is integrally formed from plate steel and includes a circular annular planar rim portion which receives the oil filter housing, a depressed annular central portion and an integral upstanding central boss having an internally threaded bore which threadably receives an oil pipe communicating with the engine block. The depressed central portion surrounding the boss includes an integral annular inclined portion having a plurality of spaced openings which receive the oil from the engine block. The oil is then circulated through the filter media and returned to the engine block through the central opening in the integral boss.  
         [0004]     Thus, the prior art oil filter mounting plate integrally formed from plate steel requires expensive forging, forming and machining operations and threading of the internal surface of the boss. In addition to the expense of and capital investment required for forging and extruding the integral boss of the prior art oil filter mounting plate, it is generally not possible to accurately form the boss and the bore through the boss perpendicular to the plane of the plate. Thus, because the bore must be internally threaded in the axis of the bore, the resulting threaded bore is not perpendicular to the plane of the plate. Then, when the prior art filter mounting plate is threaded on the pipe communicating with the engine block, the plate is canted relative to the bearing surface of the block surrounding the pipe, resulting in a poor seal and leakage. This problem is solved by the two piece oil filter mounting plate of this invention.  
         [0005]     There is therefore a need for an oil filter mounting plate which is less expensive to manufacture and which may be manufactured using mass production techniques but which provides the advantages of a unitary oil filter mounting plate including a central internally threaded bore having sufficient thickness for a plurality of threads.  
       SUMMARY OF THE INVENTION  
       [0006]     The oil filter mounting plate assembly of this invention is formed from at least two parts including a plate having a circular outer periphery and a central portion having a polygonal opening therethrough, and a nut press fit in the polygonal opening in generally sealed relation having a thickness greater than the plate and including an internally threaded central opening or bore. The nut has a thickness greater than the plate such that the internally threaded central opening of the nut thus has sufficient threads for threaded sealed securement to the oil pipe extending from the engine block, but eliminates the requirement for forging and threading after forging of a unitary part. The nut includes a polygonal outer periphery configured to be received in the polygonal opening of the plate in a press fit and a linear groove defined in opposed sides of the polygonal outer periphery of the nut receiving the plate and permanently affixing the nut to the plate in sealed relation.  
         [0007]     In the preferred embodiment, the polygonal opening through the central portion of the plate has at least five sides and the polygonal outer periphery of the nut includes a corresponding number of sides, more preferably at least six sides. In the disclosed embodiment, the linear grooves defined in the opposed sides of the polygonal periphery of the nut are defined by spaced opposed lips adjacent the opposite surfaces of the nut including a first lip overlying an adjacent surface of the plate and a second lip engaging an outer surface of the plate forming a secure and sealed attachment. In the disclosed embodiment, the bottom surface of the grooves is inclined to facilitate attachment of the nut to the plate.  
         [0008]     Further, in the preferred embodiment of the oil filter mounting plate of this invention, the plate is generally configured similar to the prior mounting plate including a generally planar annular outer rim portion having a circular outer periphery to receive the cylindrical rim of the enclosure or housing of the oil filter, an annular inclined portion integral with the planar outer rim and a planar central portion surrounding the polygonal central opening, wherein the annular inclined portion includes a plurality of spaced openings which receive the oil from the engine block as described above.  
         [0009]     The oil filter mounting plate assembly of this invention may thus be formed by conventional forming techniques which do not require forging and internally threading of a boss following manufacture of the mounting plate. Further, because the bore of the nut is threaded prior to press fitting the nut in the plate, the thread nut bore is perpendicular to the plane of the plate, reducing leakage. The mounting plate may be formed from a plate of sheet steel and the nut may be secured within the central polygonal opening in a die press. Other advantages and meritorious features of the oil filter mounting plate of this invention will be more fully understood from the following description of the preferred embodiments, the appended claims and the drawings, a brief description of which follows. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a perspective view of a preferred embodiment of the oil filter mounting plate assembly of this invention from one side of the assembly;  
         [0011]      FIG. 2  is a top view of the oil filter mounting plate assembly of  FIG. 1  from a side of the assembly opposite to  FIG. 1 ;  
         [0012]      FIG. 3  is a side crosssectional view of  FIG. 2  in the direction of view arrows  3 - 3 ;  
         [0013]      FIG. 4  is a perspective view of the nut of the oil filter mounting plate assembly illustrated in  FIGS. 1 and 2 ;  
         [0014]      FIG. 5  is a top view of the nut illustrated in  FIG. 4 ;  
         [0015]      FIG. 6  is a side crosssectional view of the nut illustrated in  FIG. 5  in the direction of view arrows  6 - 6 ; and  
         [0016]      FIG. 7  is a top view of the plate illustrated in  FIG. 2 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     As set forth above, the oil filter mounting plate assembly  20  of this invention shown in FIGS.  1  to  3  may be conventionally formed from two components comprising the plate  22  shown in  FIG. 7  and the nut shown in FIGS.  4  to  6 . The plate  22  may be formed from a metal plate, preferably steel, and includes a planar outer rim portion  26  having a circular peripheral edge  28 , an annular inclined portion  30  and a planar generally annular inner portion  32  having a polygonal opening  34 . Because the plate  22  has a uniform thickness, no forging is required, substantially reducing the cost as compared with the prior oil filter mounting plate assembly described above. The polygonal opening  34  preferably has greater than four sides, preferably at least six sides and most preferably eight sides, as shown in  FIG. 7  for example. The sides of the polygonal opening  34  are preferably linear and the polygon defined by the sides is preferably regular as shown. The inclined annular portion  30  includes a plurality of openings  38  which are preferably equally spaced as shown in  FIGS. 1, 2  and  7  which form the inlet openings for the oil filter as described above and further described below. The openings  38  may be circular as shown and formed by conventional punching techniques known in the art.  
         [0018]     The nut  22  best shown in FIGS.  4  to  6  includes an annular body  40  including a central internally threaded bore  42  and a polygonal periphery  44 . As will be understood from the description of a preferred method of forming the oil filter mounting plate assembly  20  of this invention below, the polygonal periphery  44  of the nut  22  is substantially identical to the polygonal opening  34  in the plate  22  except for the grooves  46  described below. That is, the polygonal periphery  44  of the nut has the same number of sides as the polygonal opening  44  in the plate  22  and the sides of the polygonal periphery  44  of the nut are preferably linear.  
         [0019]     The nut  24  preferably includes at least two linear grooves  46  on opposed sides of the polygonal periphery each including a linear lip  48  adjacent one side of the plate  26  and a smaller lip  50  as best shown in  FIG. 6 . The bottom wall  52  of the groove  46  is preferably inclined toward the smaller lip  50  as shown in  FIGS. 3 and 6 . The lips  48  and  50  extend linearly as shown in  FIG. 5 . In the most preferred embodiment, the diameter or major dimensions of the polygonal periphery  44  of the nut is slightly greater than the diameter or major dimensions of the polygonal opening  34  in the plate  22 , such that the nut  24  must be press fit into the polygonal opening  34  in the plate and the lip  50  overlies the surface of the planar inner portion  32  of the plate as shown in  FIG. 3 . In the most preferred embodiment of the oil filter mounting plate assembly  20 , the nut further includes an annular bearing surface  54  as best shown in  FIGS. 1 and 4 .  
         [0020]     The oil filter mounting plate assembly  20  may be assembled in a conventional die press. After forming the plate  22  from a sheet or plate of metal, preferably steel, and the nut from a metal preferably having at least the same hardness as the plate  22 , the nut  24  may be fed to an installation head attached to one platen of a die press, wherein the plate is supported on a die fixture or die button on the opposed platen of the die press (not shown). In the most preferred method of installation, the plate  22  may be simultaneously formed by suitable dies in the die press. The nut  24  is oriented in the installation head, such that the polygonal periphery  44  of the nut corresponds to the polygonal opening  34  of the plate with the lip  50  of the groove  46  opposite the plate. As the die press is closed, the nut  24  is permanently installed in and attached to the plate  22  as best shown in  FIG. 3 . The combination of the press fit and the interlock of the nut to the plate provided by the grooves  46  forms an essentially sealed connection between the nut and the plate, although an air tight seal is not required.  
         [0021]     As will be understood by those skilled in this art, various modifications may be made to the oil filter mounting plate assembly  20  of this invention within the purview of the appended claims. For example, the polygonal opening  34  in the plate  22  and the polygonal periphery  44  of the nut  24  may have six sides and the linear grooves  46  may be provided on more than two of the polygonal sides  44  of the nut  24 . However, the grooves  46  may be formed in the polygonal nut on opposed sides simultaneously further reducing the cost. As described above, the oil filter mounting plate assembly  20  of this invention may be used with any conventional oil filter including a housing or enclosure including a tubular cylindrical side wall, wherein the open end of the tubular side wall is crimped or otherwise secured to the oil filter mounting plate assembly. The oil is then circulated through the oil filter (not shown) through the openings  38 , filtered by the filter media (not shown) and returned to the engine block through a pipe threaded to the threaded opening  42  of the assembly. Having described the oil filter mounting plate assembly of this invention, it is now claimed as follows.