Abstract:
An automotive clutch housing and a method of manufacture thereof is provided. The clutch housing has a cylindrical body that is formed from a form folded strip metal sheet that is later formed into a cylindrical body. The cylindrical body is then joined to a hub to form a clutch housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/338,897 filed Feb. 25, 2010. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to clutch housings for automotive transmissions in automotive vehicles such as, but not limited to, passenger vehicles, motor cycles, rough-terrain vehicles and trucks. 
       BACKGROUND OF THE INVENTION 
       [0003]    Many, if not most, automotive clutch housings are fabricated from a cylindrical work piece. Spline teeth are then formed or cut into the cylindrical work piece. It is desirable to provide a clutch housing where the spline teeth of the clutch housing can be formed on a generally flat work piece that is later formed into a cylinder. 
       SUMMARY OF THE INVENTION 
       [0004]    In a preferred embodiment, the present invention provides a clutch housing that is formed from a work piece of sheet strip material. The work piece has spline teeth fold formed thereon. The form folded work piece is then formed into a cylinder and is connected with a hub portion of a clutch housing. 
         [0005]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0007]      FIG. 1  is a perspective view of a cylindrical body of the clutch housing according to the present invention; 
           [0008]      FIG. 2  is a schematic view illustrating a forming operation of the cylindrical body shown in  FIG. 1 ; 
           [0009]      FIG. 3  is a perspective view of a cylindrical body joined to a hub to form a clutch housing according to the present invention; 
           [0010]      FIG. 4  is a front elevational view of a cylindrical body utilized in an alternate preferred embodiment clutch housing of the present invention; 
           [0011]      FIG. 5  is an enlargement of a portion encircled in  FIG. 4 ; 
           [0012]      FIG. 6  is a perspective view of a clutch housing utilizing a cylindrical body shown in  FIG. 4 ; 
           [0013]      FIG. 7  is a cut away partial sectioned perspective view of the clutch housing shown in  FIG. 6 ; 
           [0014]      FIG. 8  is a sectional view similar to that of  FIG. 7  of another alternate preferred embodiment clutch housing according to the present invention; 
           [0015]      FIG. 9  is a sectional view similar to that of  FIG. 8  illustrating yet another alternate preferred embodiment clutch housing according to the present invention; 
           [0016]      FIG. 10  is a partial perspective view of the clutch housing shown in  FIG. 9  from an opposite direction; 
           [0017]      FIG. 11  is a view similar to that of  FIG. 10  of yet another alternate preferred embodiment clutch housing according to the present invention; 
           [0018]      FIG. 12  is a partial perspective view of a cylindrical body which can be utilized as an alternative to the cylindrical body shown in the clutch housings illustrated in  FIGS. 9 ,  10  and  11 ; 
           [0019]      FIG. 13  is a top view of a clutch housing of yet another alternate preferred embodiment of the present invention; 
           [0020]      FIG. 14  is a sectional view taken along lines  14 - 14  of  FIG. 3 ; 
           [0021]      FIG. 15  is a perspective view of the clutch housing shown in  FIG. 13 ; 
           [0022]      FIG. 16  is a front perspective view of a hub utilized in the clutch housing shown in  FIG. 13 ; 
           [0023]      FIG. 17  is a rear perspective view of the hub shown in  FIG. 16 ; 
           [0024]      FIG. 18  is a front view of the hub shown in  FIG. 16 ; 
           [0025]      FIG. 19  is a sectional view of the hub shown in  FIG. 16  taken along lines  19 - 19  of  FIG. 18 ; 
           [0026]      FIG. 20  is an enlargement of a portion that is circled in  FIG. 18 ; 
           [0027]      FIG. 21  is a side perspective view of the hub shown in  FIG. 16 ; and 
           [0028]      FIG. 22  is an enlargement of a portion  22  encircled in  FIG. 21 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
         [0030]    Referring to  FIG. 1 , an unfinished cylindrical body  10  for the clutch housing  7  ( FIG. 3 ) according to the present invention is shown. The cylindrical body  10  is fabricated from a fold formed strip sheet metal work piece. Typical cylindrical body  10  thicknesses can be approximately 1.5 mm. The cylindrical body  10  has a series of spline teeth  14 . The spline teeth  14  of the cylindrical body has an inner flat  13  and an outer flat  15  that are joined by slope portions  17 . The spline teeth  14 , as schematically shown in  FIG. 2 , can be roll formed from a continuous flat strip  16 . The strip  16  is taken off from a bobbin  18 . After interacting with a combination of lower and upper rollers  20  and  22  or a series of such rollers, a series of spline teeth  14  are formed on the cylindrical body  10 . In a subsequent operation (not shown), an individual cylindrical body is cut off. The cylindrical body  10  also has along its opposite ends, a dove tail interlock joint comprising a male tab  24  and a corresponding female cut out  26 . The spline teeth  14  have a series of punched out oil slots  28 . The ends of the cylindrical body  34  and  36  are brought together to form the cylindrical shape of the cylindrical body and a connective interlock is formed by the dove tail joint  24 ,  26  thereafter the ends  34 ,  36  are joined preferably by welding, clenching or brazing. In another embodiment (not shown) the cylindrical body can be formed as a stamping that is progressively stamped by dies which translate toward one another. 
         [0031]    Referring the  FIG. 3 , the cylindrical body  10  is permanently connected with a hub  40 . The hub  40  along its inner diameter (not shown) has a series of spline teeth to allow the hub to torsionally interact with a shaft. As shown, clutch housing  7  can function with clutch plates within its inner diameter or with clutch plates riding on its outer diameter. 
         [0032]    Referring to  FIGS. 4 ,  5 ,  6  and  7 , a clutch housing  107 , according to the present invention, is provided. The clutch housing  107  has a cylindrical body  110  that is fabricated from a blank strip  112 . The blank strip  112  has along its opposite ends  114  and  116 , double male dove tail interlocks  118  and female dove tail inserts  120  respectively. The blank strip  112  also has a series of oil slots  122 . The oil slots  122  are axially staggered along a rotational axis of the clutch housing. The blank strip  112  also has stamp formed thereto, integral tab members  126 . The tab members  126  are connected to a remainder of the cylindrical body by a neck  128 . Clutch housing  107  has a hub  140 . The hub  140  has a disc portion  144  that is integrally joined to a tubular or cylindrical portion  146 . The disc portion  144  has an annular groove  142 . An inner diameter of the cylindrical portion  146  has spline teeth  148  allowing the hub  140  to be connected with or turned by a shaft passing through its inner diameter. The tabs  146  abut the hub  140  and are connected thereto typically by a welding process. Spline teeth  136  have an outer radial flat  130  and an inner radial flat  132  that are joined by slope portions  133 . As shown, typically clutch housing  107  has the friction disk or divider plates slidably mounted on its outer diameter. 
         [0033]    Referring to  FIG. 8 , a clutch housing  207  is provided. Clutch housing  207  has a hub  240  substantially similar to previously described hub  140  for clutch housing  107 . However, the hub  240  has an annular groove  242  that additionally has gear tooth shaped radially inward directed depressions  218 . The cylindrical body  210  has spline teeth  214  with stem portions  213  connected with radially inwardly bent tabs  212 . Tabs  212  have a radially inward projecting portion  216  that is fitted within the gear tooth depression  218  of the hub to provide a gear tooth like circumferential inner lock between the cylindrical portion  210  and the hub  240 . Again, the tabs  212  are typically welded to the hub  240 . 
         [0034]    Referring to  FIGS. 9 and 10 , a clutch housing  307  is provided. Clutch housing  307  has a hub  340  that is essentially similar to the hub  140  previously described. The hub  340  has a cylindrical groove  342 . A cylindrical body  310  has generally rectangular shaped tabs  318  that are connected with the hub  340  by rivets  320 . The rivets  320  have a head that is generally flush with the surface  322  of a disc portion  324  of the hub  340 . 
         [0035]    Referring to  FIG. 11 , an alternate preferred embodiment  357  of the present invention is provided that is essentially similar to clutch housing  307 . However, the hub  341 , in its disc portions interior surface  360  adjacent to heads the rivets  320  utilized to connect the cylindrical body  310  to the hub  341  has a slight depression cut out  358 . The cut out  358  allows the head of the rivet  320  to be radially enlarged in the attachment operation. 
         [0036]    Referring to  FIG. 12 , an alternate preferred embodiment cylindrical body  370  is provided that can be utilized with the hubs  340 ,  341  shown in  FIGS. 9 ,  10  and  11 . Cylindrical body  370  has a series of tabs  372  with compound stems  374  attaching the radial tabs  372  with the remainder of the cylindrical body  370 . 
         [0037]    Referring to  FIGS. 15-22 , a clutch housing  407  is provided. Clutch housing  407  has a hub  440 . Hub  440  has a disc portion  442  integrally connected with a cylindrical portion  444  having internal spline teeth  446 . The hub  440  has a series of apertures  448  to allow for passage of rivet fasteners  450  that connects the hub  440  with a cylindrical body  410 . The hub  440  along its peripheral surface has a series of radially projecting gear like teeth  451 . Alternating teeth  451  have radial overhangs  452 . The radial overhangs  452  are continuous with vanes  454  that are formed by depressions  458  in an outer surface of the hub disc portion  442 . Cylindrical body  410  has roll formed spline teeth  414  that have a series of axially alternating positioned oil slots  416 . The cylindrical body  410  has a generally axial portion  418  and radially inwardly bent tabs  420 . Between the generally cylindrical portion  418  and the radially inwardly bent tabs  420  is a transition region  422 . Between the tabs  420  within the transition region  422 , there are slots  424 . Connecting the generally cylindrical body  410  with the hub  440  are a series of rivets  450 . The radial tabs  420  are aligned with the hub depressions  458  and the hub&#39;s radial gear like teeth  451  are aligned with an outer radial flat  417  of the spline teeth  414  of the cylindrical body  410 . Additionally, the gear teeth  451  aid in supporting the spline teeth  414  in the transition region  422 . The webs  454  and their slot  424  received radial overhangs  452  provide for a circumferential interlock and torsional force transfer to the cylindrical body tabs  420 . In the transition region  422 , the aforementioned interlock inhibits a propagation of cracks in the cylindrical body  410 . 
         [0038]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.