Abstract:
A Twist-interlocking Engine Housing and Air Filter System and Method is disclosed. The filter assembly provides unequaled ease of installation and removal, as well as superior sealing between the housing and the filter assembly. For installation, the user needs only to insert the filter into the housing and then give the filter assembly a one-quarter turn or less to lock the filter assembly into the housing. There are features within the filter base that snap-locks the filter in place to resist inadvertent loosening. Finally, the housing and filter are designed so that the outer flange of the filter base is recessed into the side of the housing in order to prevent the intrusion of unwanted grime and/or fluids.

Description:
[0001]    This application is filed within one year of, and claims priority to Provisional Application Ser. No. 62/348,253, filed Jun. 10, 2016, and Provisional Application Ser. No. 62/368,602, filed Jul. 29, 2016. 
     
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
       [0002]    This invention relates generally to internal combustion engine accessories and, more specifically, to a Twist-interlocking Engine Housing and Air Filter System and Method. 
       2. Description of Related Art 
       [0003]    Cold air intakes and after-market air intake filters are very popular accessories installed on automobile engines in order to increase horsepower at a very reasonable cost. These kits are usually very amenable to do-it-yourself installation. One issue with modern vehicles (particularly turbocharged engines) is that the engine compartment has become more and more crowded, and there is less space available for the extra piping, housing and plenums that usually make up these intake kits. One approach to overcoming these space limitations is to reduce the number of components in the cold-air intake tract. In particular, manufacturers have created “one-piece” intake systems. The one-piece name refers to the placement of the air filter within the air intake housing, as opposed to having the air filter attached to the leading end of the intake hose/pipe. This approach reduces overall piping length, while also creating a sealed system that is easier to install than prior systems. 
         [0004]    In a one-piece system, the air filter needs to attach to the intake housing as well as to the piping interconnecting the filter/housing to the engine air intake.  FIG. 1  depicts one exemplary approach to a filter for such a one-piece housing. 
         [0005]    The filter assembly  70  has a lower base portion  72 , which is typically made from silicone or similar soft, pliable material. A filter element  74  is bonded to, and extends upwardly from, the base portion  72 . The intake hose (not shown) will be inserted into, and pipe-clamped to, the hose interface  82 . 
         [0006]    What is unique about these filters  70  are the deflectable tabs  78  extending around the upper periphery of the base portion  72 . These tabs  78  are intended to deflect when the user pushes the filter assembly  70  into the housing (not shown). Once the tabs  78  push past the wall of the housing (not shown), they will snap back into their undeflected condition once they are inside of the housing. At that point, the tabs  78  will prevent the filter  70  from being removed from the housing unless it is pryed or pulled out with substantial force. This process can be very awkward because of the tight confines within the engine compartment, and filter replacement can require partial disassembly of the cold air intake system. 
         [0007]    The other problem with this design is that there is quite a large gap  80  between the deflectible tabs  78  and the base flange  76 . The base flange  76  remains external to the housing (not shown), while the tabs  78  are internal to the housing when the filter  70  is installed. This gap  80  must be left so wide in order that the tabs  78  have enough room to deflect down when the filter  70  is inserted through the hole in the side of the housing. The problem is that once the tabs  78  return to their undeflected condition (shown here), the gap  80  substantially exceeds the wall thickness of the housing. This means that the filter  70  will not seal tightly to the housing, and can even be capable of rattling loosely when the engine is running. This looseness creates air leaks in the system (since the system is under suction), which will allow hot air from the engine compartment into the air intake stream. This partially defeats the purpose and benefit of the cold air intake system. 
         [0008]    This invention seeks to cure the air leakage problem in traditional housing-mounted engine air cleaners by creating a quarter-turn twist-lock filter and a housing with a receptacle formed in it that cooperates with the twist-lock filter. 
       SUMMARY OF THE INVENTION 
       [0009]    In light of the aforementioned problems associated with the prior devices and methods, it is an object of the present invention to provide a Twist-interlocking Engine Housing and Air Filter System and Method. The filter assembly should provide unequaled ease of installation and removal, as well as superior sealing between the housing and the filter assembly. For installation, the user should need only to insert the filter into the housing and then give the filter assembly a one-quarter turn or less to lock the filter assembly into the housing. There should be features within the filter base that snap-locks the filter in place to resist inadvertent loosening. Finally, the housing and filter should be designed so that the outer flange of the filter base is recessed into the side of the housing in order to prevent the intrusion of unwanted grime and/or fluids. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, of which: 
           [0011]      FIG. 1  is a side view of a prior version of a press-in filter assembly; 
           [0012]      FIG. 2  is a side view of a preferred embodiment of the twist-lock filter assembly of the present invention; 
           [0013]      FIG. 3  is a perspective view of a preferred embodiment of the air intake housing for a twist-lock filter of the present invention; 
           [0014]      FIG. 4  is another perspective view thereof; 
           [0015]      FIG. 5  is a partial view depicting the filter socket area thereof; 
           [0016]      FIG. 6  is a partial view of the peripheral flange thereof; 
           [0017]      FIG. 7  is a partial front view thereof; 
           [0018]      FIG. 8  is a perspective view of the filter assembly of  FIG. 2 ; 
           [0019]      FIG. 9  is a partial perspective view of the base area thereof; 
           [0020]      FIG. 10  is a top view of the filter assembly thereof; and 
           [0021]      FIG. 11  is a bottom perspective view thereof. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]    The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventors of carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a Twist-interlocking Engine Housing and Air Filter System and Method. 
         [0023]    The present invention can best be understood by initial consideration of  FIG. 2 .  FIG. 2  is a side view of a preferred embodiment of the twist-lock filter assembly  40  of the present invention. This assembly  40  cures the two problems with the prior one-piece filter housing/filter combinations by (a) providing a secure, airtight seal between the filter assembly  40  and the housing (not shown), and (b) allowing the user to easily remove the filter assembly  40  by simply twisting the assembly ⅛th of a turn an pulling it out. This can easily be done while the air intake system otherwise remains assembled. 
         [0024]    The improvement to the assembly  40  is located in the base portion  48 . Instead of employing several thin deflectable tabs to secure the filter assembly  40  into the housing, this device utilizes thicker, curved (arcuate) tabs  50 . In this version, there are four tabs  50  in equal spaced relation around the periphery of the base portion  48 . As should be apparent, the housing wall gap  51  between the bottom surface of tabs  50  and the top surface of the base flange  49  is much smaller than the prior filter assemblies [ 70 ]. A width of approximately 4 millimeters for the gap  51  has found to be very suitable, whereas the gap [ 80 ] of the prior assembly [ 70 ] is in excess of 10 millimeters. As will be discussed below, the housing of the present invention includes a wall thickness of approximately 5 millimeters at the point of attachment of the filter assembly  40 . This means that there should be a slight interference fit between the filter assembly  40  and the housing—the flexible nature of the silicone material of the base portion  48  will allow this much flex in the arcuate tabs  50 , without there being any air gaps at the interface (or rattling). As with the prior filter assembly, a hose will insert into, and be clamped to, the hose interface  54 .  FIG. 3  introduces the housing the cooperates with this filter assembly  40 . 
         [0025]      FIG. 3  is a perspective view of a preferred embodiment of the air intake housing  10  for a twist-lock filter [ 40 ] of the present invention. The air intake housing  10  is predominantly comprised of the housing  14  (preferably from blow-molded plastic). The filter socket  12  is formed in one side of the housing  14 —it is an aperture formed in the wall of the housing  14  (so that the filter assembly [ 40 ] will reside in the inner chamber  20  when the filter assembly [ 40 ] is locked into the socket  12 . 
         [0026]    There is a peripheral rim  13  surrounding the opening into the chamber  20 , with the rim  13  being the outermost surface of the housing  14 . A peripheral flange  22  is recessed below the surface of the rim  13  (creating a sidewall interconnecting the two—see element  24  in  FIG. 7 ). The base flange [ 49 ] seals against the face of the peripheral flange  22  when the filter assembly [ 40 ] is seated and twist-locked. Because the flange  22  is recessed, the base flange [ 49 ] is actually recessed below the surface of the rim  13  (or at least flush with it), which creates a cleaner finished product which resists the intrusion of dirt or liquid to interfere with the sealing surface between the filter assembly [ 49 ] and the housing  14 . 
         [0027]    In this version, four arcuate notches  16  are cut into the inner edge of the flange  22 —these are sized and positioned to cooperate with the arcuate tabs [ 50 ] so that the tabs [ 50 ] will insert into the notches  16 . There are also radial notches  18  formed in the face of the peripheral flange  22 . Here there are four notches  18 —each is centered between each arcuate notch  16 . These notches  18  provide for a positive “click” between the filter assembly [ 40 ] and the flange  22  when the filter assembly [ 40 ] is rotated until it is in the locked position. As is depicted in  FIGS. 8 and 9 , there are radial tabs extending upwardly from the base flange under each arcuate tab [ 50 ] that are formed to fit into these notches  18 . 
         [0028]      FIGS. 4, 5, 6 and 7  are additional views of the filter socket region of the housing  14 —they are provided to insure that even the smaller features comprising the filter socket  12  are clear. 
         [0029]      FIG. 8  is a perspective view of the filter assembly  40  of  FIG. 2 . The arcuate tabs  50  taper into the wall of the base portion  44  so that they can be smoothly inserted into the arcuate notches [ 16 ], and then the assembly  40  can be twisted without the edges of the tabs  50  snagging so that the rotation is smooth and unobstructed. As can be seen, the radius that defines the arc of the tabs  50  is much smaller than the radius that defines the outer periphery of the base flange  48  or the filter engagement portion  80  of the assembly  40 . In fact, a tab  50  radius of 50% or less than the radius of the filter engagement portion  80  has been seen to be suitable. 
         [0030]    As can be seen here, the radial tabs  52  extend radially outward from the center periphery of the housing-facing face of the base flange  48 . As discussed above, these tabs  52  are formed so that they will fit snugly into the radial notches  18  formed in the peripheral flange [ 22 ] of the housing [ 14 ]. Finally, the closed cap portion  46  to the filter element  42  can be seen here—other configurations are also possible. 
         [0031]      FIGS. 9 and 10  are additional views of the base portion region of the filter assembly  40 —they are provided to illuminate the details of, and relationships between, the arcuate tabs  50  and the radial tabs  50 . 
         [0032]    If we finally turn to  FIG. 11 , we can examine yet another unique feature of the instant design.  FIG. 11  is a bottom perspective view of the hose interface  54  area of the filter assembly  40 . As discussed above, the hose interface  54  is configured to accept an intake hose within it. To that end, an intake hose throat  56  is formed in the hose interface  54  that defines an inner wall  58 . There are a plurality of staggered ridges  60  protruding into the throat  56 . These ridges  60  assist in the grasping force between the hose interface  54  and the intake hose (i.e. when the hose clamp is tightened around the hose interface  54 ). The prior filters do not use staggered ridges  60 , but rather use continuous ring-shaped ridges that completely encircle the throat  56 . The use of staggered (non-continuous) ridges  60  allows the ridges  60  to compress when the hose clamp is tightened without causing ripples in the hose interface  54 . The improved compressibility comes from the spacing between the ridges  60  in reach row—this spacing can compress without compressing the ridges  60  themselves. 
         [0033]    Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.