Abstract:
An air cleaner that locks two shells together by a cam action is disclosed having two shells with interlocking fingers staggered along at least one length of the joint between the first and second shells. A cam is inserted between the interlocking fingers and when rotated pulls the fingers apart and pulls the two shells together.

Description:
FIELD OF THE INVENTION 
     The invention relates generally to air cleaner housings for motor vehicles. In particular, it relates to devices and methods for attaching air cleaner shells and compressing filter elements. 
     BACKGROUND OF THE INVENTION 
     Air cleaner housings for motor vehicles are typically arranged to support a disposable air filter element between two shells. The shells are disposed about the inlet side of the air cleaner and the outlet side of the air cleaner and serve to gather the air across the broad surface of the air cleaner and direct it to an air passageway. Adequate sealing must be provided between the edge of the two air cleaner shells and the disposable air cleaner element itself to prevent air from leaking around the side of the air cleaner element without passing through the air cleaner element and continuing on to the intake manifold and the engine. For this reason, a flexible seal is often provided between the periphery of the air cleaner and the air cleaner housing itself. The seal prevents air from bypassing around the edge of the air cleaner. 
     A problem with many air cleaner designs is that the seal is compressed to provide an airtight seal. Disposable air cleaner elements typically require a seal having a length of at least two linear feet (for a six inch by six inch disposable air cleaner element) and can go as large as three or three and a half feet in length. Compressing this length of seal requires a significant force. Prior art air cleaner housings have addressed this problem by being constructed as two roughly hemispherical shells, with the disposable air cleaner element sandwiched between, looking much like the popular hamburger. To replace the disposable air cleaner element, the top shell is unscrewed from the bottom shell, the disposable elements exchanged, and the top shell screwed back on the bottom shell with the new air cleaner element between. A primary drawback of this method is the need for even tensioning of the two shells together and hence the requirement of many screw fasteners evenly spaced around the periphery of the air cleaner shells coupling them together. This arrangement requires a significant amount of time to both unscrew and rescrew the connectors. 
     What is needed, therefore, is an improved air cleaner that is capable of more rapid air cleaner element replacement. 
     SUMMARY OF THE PRESENT INVENTION 
     In accordance with a first embodiment, an air cleaner for the combustion air of an internal combustion engine is provided, having a first air cleaner shell with a first plurality of spaced-apart fingers along the first edge thereof, a second air cleaner shell with a second plurality of spaced-apart fingers along the first edge thereof, wherein the first and second plurality of fingers are intertwined to form a passageway therebetween, and a cam shaft disposed in the passageway and abutting the intertwined fingers, to hold the intertwined fingers apart and the first and second shells together when in a first rotational position, and to permit the fingers to come together and the shells to move apart when in a second position. The air cleaner may also include a replaceable air cleaner element in the form of a panel having a first and a second side where the first side of the air cleaner element is supported by the first air cleaner shell and the second side of the air cleaner element is supported by the second air cleaner shell. The air cleaner cam shaft may include a length disposed in the passageway having an overall major width greater than an overall minor width and a handle coupled to and extending away from the camming length to rotate the camming length within the passageway. One of the first and second shells may include a surface that abuts the handle to prevent the handle from rotating in a first direction when the cam shaft is in the second position. One of the first and second shells may include a catch that abuts the handle to prevent the handle from rotating in a second direction opposite the first direction when the cam shaft is in the second position. The first plurality of fingers may be staggered with the second plurality of fingers along the first edge. The first and second plurality of fingers may define a passageway having a major width substantially parallel to a planar extent of the air cleaner element and a minor width smaller than the major width substantially perpendicular to the planar extent of the air cleaner element. The passageway may be substantially elliptical when the cam shaft is in the first position. 
     In accordance with the second embodiment of the invention, an air cleaner for the combustion air of an internal combustion engine is provided, including a first air cleaner shell with a first concave inner surface and a first peripheral edge, a second air cleaner shell with a second concave inner surface and a second peripheral edge and removably fixed to the first air cleaner shell, that the first peripheral edge is adjacent to the second peripheral edge about substantially the entire periphery of the first and second air cleaner shells, a removable air cleaner element disposed inside the filter housing having a third peripheral edge sealed against the first or second peripheral edges about substantially the entire periphery of the air cleaner element, a first plurality of fingers fixed to and extending from the first peripheral edge toward the second peripheral edge, a second plurality of fingers fixed to and extending from the second peripheral edge toward the first peripheral edge such that a passageway having a major and a minor width is defined between the first and second pluralities of fingers, and such that when the passageway is enlarged the first and second shells move closer together, and a cam shaft disposed between the first and second pluralities of fingers to enlarge the passageway and move the first and second shells closer together. The first and second peripheral edges may define at least first and second straight joints on imposing sides of the air cleaner and further the first and second plurality of fingers may be disposed along the first straight joint. First and second shells may be hingably coupled along the second straight joint. The first and second straight joints may be substantially parallel. The passageway may have a substantially elliptical shape when the first and second shells are in a first position and may have a substantially circular shape when the first and second shells are in a second compressed position. 
     In regard to a third embodiment of the invention, a method of assembling an air cleaner is provided including the steps of intertwining the first and second plurality of fingers to provide a passageway therebetween having a major width and a minor width smaller than the major width, inserting the cam shaft lengthwise into the passageway such that a major width of the cam shaft is aligned with the major width of the passageway and a minor width of the cam shaft is aligned with the minor width of the passageway, rotating the cam shaft in a first rotational direction through an arc of between 90° and 150°, and abutting a lever that is fixed to and extends radially away from the cam shaft against a surface of the air cleaner that is disposed to prevent further rotation of the cam shaft in the first rotational direction. 
    
    
     Other principal features and advantages of the invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description and the appended claims. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1A and 1B are assembled and exploded perspective views, respectively, of an air cleaner in accordance with the present invention; 
     FIG. 2 is a detailed partial perspective view of one end of the air cleaner of FIG. 1 showing the interengaging fingers of the upper and lower air cleaner shells; 
     FIG. 3 is a partial cross-sectional view of the air cleaner of FIGS. 1 and 2 showing a portion of the air cleaner shells and the rotatable cam for coupling the shells in an initially inserted position; and 
     FIG. 4 shows the same cross-sectional view of FIG. 3, but with the cam in a rotated and locked position. 
    
    
     Before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1A and 1B, an air cleaner  10  is shown including an upper air cleaner shell  12  and a lower air cleaner shell  14  with a replaceable air cleaner element  16  between the shells. A hinge  18  is provided at one end of the air cleaner shells  12  and  14  coupling the edges of the air cleaner shells at that end and permitting the shells to be pivotally opened. A cam shaft  20  is disposed between intertwined fingers  22  extending downward from upper air cleaner shell  12  and upwards from the lower air cleaner shell  14 . 
     Air cleaner shells  12  and  14  define an air cleaner housing that encloses and seals against the periphery of air cleaner element  16 . Upper air cleaner shell  12  has an air conduit  24  that passes through the wall of upper air cleaner shell  12  and provides a convenient mounting point for air conduits leading raw air into the air cleaner (not shown). Lower air cleaner shell  14  includes an air conduit  26  that provides a convenient coupling point for air conduits leading filtered air away from the air cleaner and to the engine. 
     Replaceable air cleaner element  16  includes a zigzagged paper or synthetic air cleaning medium  28  that removes particulate matter from the raw air as it passes through the cleaning medium. The periphery of medium  28  is provided with a resilient seal  30  that is typically molded to the periphery of the cleaning medium, or fixed to a rigid or semin-rigid framework that also extends about the periphery of the air cleaning medium  28 . It is this seal that engages the inner walls of the air cleaner housing and prevents raw air from passing around the periphery of the air cleaner and not being cleaned. 
     The air cleaner element is in the form of a panel having an air receiving surface  32  and an air emitting surface  34 . It is positioned within the air cleaner housing such that air is drawn through conduit  24 , into the upper air cleaner shell  12 , it contacts the air receiving surface  32 , passes through the air cleaning medium  28  and exits the air cleaner element  16  from air emitting surface  34 . The air then travels through lower air cleaner shell  14  and exits through lower air conduit  26  from whence it travels to the engine to be combined with fuel and burned. 
     Referring to FIG. 3, air cleaner element  16  is positioned within the air cleaner housing such that a lower surface  35  of the air cleaning element  16  is supported by an upwardly facing surface  36  of the lower air cleaner shell  14 . The air cleaner element  16  is also maintained in position within the air cleaner housing by a downwardly facing surface  38  of Lipper air cleaner shell  12  that abuts upwardly facing surface  37  of air cleaner element  16 . Resilient seal  30  is disposed between these surfaces and is compressed when the surfaces are forced toward one another. In the illustrated embodiment, resilient seal  30  defines both surfaces  35  and  37  abuts both upwardly facing surface  36  and downwardly surface  38 . This is the preferred embodiment. It is anticipated, however, that the resilient seal need only define one of surfaces  35  and  37  to adequately block the path of raw air around the periphery of air cleaner element  16 . 
     When an air cleaner element  16  is placed in one shell of the housing and the housing closed, the housing will typically not make adequate contact with the seal, as shown. To provide adequate contact, and thereby to prevent the flow of raw air around the edge of element  16  from the outside to the air emitting side of the cleaner element, some significant force must be applied to the upper and lower air cleaner shells  12 ,  14  to force them together and thereby deform the resilient seal. To provide this force, several intertwining fingers  22  are disposed on both the upper air cleaner shell  12  and the lower air cleaner shell  14 . These fingers are disposed in a staggered spacing such that they intertwine when upper air cleaner shell  12  is closed on lower air cleaner shell  14  as best shown in FIGS. 1A and 3. These fingers are staggered and preferably extend substantially the entire length of the free edges from which they depend. 
     When the two shells are closed and the fingers intertwined, a passageway  40  is defined by the fingers into which the cam shaft  20  is inserted. This passageway has a major width W 1  that is greater than a minor width W 2  when the cam shaft is inserted into passageway  40 . Passageway  40 , because of this difference in width, has a generally elliptical shape when viewed end-on as shown in FIG.  3 . The major width W 1  of passageway  40  lies in a plane that is substantially parallel to the planar extent of the air cleaner element and also to the plane defined by the junction of the two air cleaner shells. Minor width W 2  is substantially at a right angle to major width W 1  and thus is substantially perpendicular to the planar extent of the air cleaner element and also the plane defined by the junction between the two shells of the air cleaner. As shown in FIG. 3, when the cam shaft is initially inserted into passageway  40 , passageway  40  is substantially elliptical. 
     Cam shaft  20  has a length  42  that extends through passageway  40 . Length  42  has a major width  44  greater than a minor width  46 . Because of this difference between the major width and the minor width, cam shaft  20  acts as a cam when it is rotated in passageway  40 . It forces the fingers apart as shown in FIG. 4 (as compared to FIG. 3) and thereby pulls upper air cleaner shell  12  and lower air cleaner shell  14  closer together. This action compresses resilient seal  30  against downwardly facing surface  38  of upper air cleaner shell  12  and prevents raw air from bypassing the air cleaner element  16 . In FIG. 3, which shows the position of the assembly when the cam shaft is first inserted, the major width  44  of cam shaft  20  is substantially parallel to the major width W 1  of passageway  40 . Similarly, the minor width  46  of cain shaft  20  is substantially parallel to minor width W 2  of passageway  40 . 
     Cam shaft  20  includes a handle  48  that extends away from length  42  of cam shaft  20  at an angle of preferably 90° as shown in FIG.  2 . This handle provides the operator with the mechanical advantage necessary to rotate cam shaft  20  in passageway  40 . Once rotated, as shown in FIG. 4, handle  48  is held in its rotated position between catch  50  disposed on an adjacent edge of upper air cleaner shell  12  and stop  52  which extends from an adjacent surface of lower air cleaner shell  14 . Handle  48  is prevented from rotating in a clockwise manner (as shown in FIGS. 2 and 4) because it abuts catch  50  and is prevented from rotating in a counter-clockwise manner because it abuts stop  52 . In this manner, catch  50  and stop  52  prevent the rotation of handle  48 , and hence hold cam shaft  20  in its locked position. To open the air cleaner housing, handle  48  is pulled outward from catch  50  flexing finger  54  outward and rotated counterclockwise from the position shown in FIG. 4 to the position shown in FIG.  3 . This permits passageway  40  to collapse in size as the intertwined fingers  22  of the opposing shells move closer together, releasing the pressure applied to seal  30  and permitting cam shaft  20  to be withdrawn from passageway  40 . 
     To assemble the air cleaner, upper air cleaner shell  12  and lower air cleaner shell  14  are closed such that the fingers of shell  12  and shell  14  are intertwined thereby providing passageway  40  therebetween. In this position, as generally shown in FIG. 3, an elliptical passageway having a major width and a minor width smaller than the major width is provided. At this point, the camming length  42  of cam shaft  20  is inserted lengthwise into passageway  40  such that the major width of the cam shaft is aligned with the major width of the passageway and the minor width of the cam shaft is aligned with the minor width of the passageway, as shown in FIG.  3 . At this point, the cam shaft can be rotated clockwise to an arc of preferably between 60° and 140° which causes the major width of the cam shaft to force the intertwined fingers apart and force the shells together compressing the resilient seal. At this point, the lever will abut catch  50  which has a surface that prevents further rotation of handle  48  of cam shaft  20 . 
     While the preferred embodiment of the invention is as described above, there are several substitutions that may be made without departing from the beneficial features of the above-described invention. For example, rather than a hinge  18 , a similar arrangement of interlocking fingers and a cam shaft may be employed. This would provide for camming engagement two opposing ends of the air cleaner. The hinge may also be replaced with such well known substitutions as an interlocking tab and slot arrangement which would have the added benefit of permitting the upper air cleaner shell to be removed entirely. In the example above, a thin seal at the edge of the air cleaner was compressed between facing surfaces of the upward and lower air cleaner shells. Alternatively, the lower air cleaner shell may not support the thin seal but the bottom surface of the air cleaner. 
     Thus, it should be apparent that there has been provided in accordance with the present invention a cam action attachment and locking mechanism for air cleaner shells that fully satisfies the objectives and advantages set forth above. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.