Abstract:
A rear end gear box cover for a racing car is formed with a fixed base plate and a removable top plate. The base plate is fixed to the rear end housing by multiple fasteners while the top plate is removable from the base plate. The top plate includes a pair of opposing cam members carrying connector pins for engagement with receiver mounts formed on the base plate. A cam driver on the top plate has a central connector member that when rotated drives a pair of opposing cam pins carried in a slotted opening on the cam members outwardly to force the connector pins into openings in the receiver mounts and secure the top plate to the base plate. A detent mechanism in each of the slotted openings retains the cam members in a locked position. A quarter turn of the connector member retracts the connector pins.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to a gear box cover for a racing car for which rapid access is required, and, more particularly, to a cover for a rear end gear box on a race car, such as a sprint race car, modified, late model, and/or street rods, which provides internal access to the gear box through manipulation of a single connector member. 
         [0002]    Race cars, particularly sprint cars and smaller racing cars, are powered by an engine supported in a frame and connected to a rear end gear box that transfers rotational power to the rear wheels of the racing car. The rear end gear box has a pair of intermeshed gears with an input gear associated with the drive input from the engine and a transfer gear transferring rotational power from the input gear driven from the engine to the rear wheels of the racing car. Depending on the configuration of the rotational components of the rear end of the racing car, the input and transfer gears can be vertically aligned or offset horizontally as depicted in  FIG. 1  and described in greater detail below. In either prior art configuration, the rear end gear box is provided with a cover that is secured to the gear box housing by fasteners and sealed with a gasket or O-ring. Whenever access to the interior of the rear end gear box is required, the fasteners must be disengaged from the housing to allow the cover to be removed. 
         [0003]    Removal of the cover on the rear end gearbox is necessary to replace the input and/or transfer gears to maintain or repair the rear end gear box. In some instances, both the input and transfer gears are removed and replaced with similar input and transfer gears having different gear ratios. The input and transfer gears are splined onto the respect input shaft from the engine and the parallel transfer shaft that delivers rotational power to the rear end and the rear wheels. The cover is provided with a pair of bearings that rotatably support the respect ends of the input and transfer shafts beyond the mounting of the input and transfer gears. These bearings require a certain thickness in the cover in order to support the bearings for operative use. 
         [0004]    The removal of the rear end gear box cover requires the manipulation of each of several bolts that secure the cover onto the gear box housing. Each bolt is threaded into a boss on the gear box housing and requires a socket wrench to remove each respective bolt. This process of removing the rear end gear box cover typically takes approximately twenty minutes to accomplish. If required prior to the start of a race, or even during the race, this length of time to remove the bolts securing the cover to the gear box housing can make the difference between racing and not racing. 
         [0005]    Therefore, it would be desirable to provide a rear end gear box for a racing car that could be easily and quickly removed to permit access to the input and transfer gears within the rear end gear box. 
       SUMMARY OF THE INVENTION 
       [0006]    It is an object of this invention to provide a rear end gear box cover for a racing car in which the cover can be quickly and easily removed to permit access to the interior of the rear end gear box. 
         [0007]    It is another object of this invention to provide a rear end gear box cover that can be removed through the manipulation of a single connector member. 
         [0008]    It is still another object of this invention to provide a gear box cover in which the cover includes a cam mechanism that drives connector pins into receivers to secure the cover to the gear box housing. 
         [0009]    It is a feature of this invention that the rear end gear box cover can be removed with a quarter turn of a wrench. 
         [0010]    It is another feature of this invention that the turning of the connector member rotates a cam driver that moves cam plates bearing the connector pins to engage receivers formed on a base plate member secured to the rear end housing. 
         [0011]    It is an advantage of this invention that the rear end gear box cover can be removed from the rear end gear box in a matter of seconds rather than minutes. 
         [0012]    It is another advantage of this invention that the replacement of the input and/or transfer gears within the rear end gear box can be accomplished in a quicker time than previously known in the art, which can enable a racing car to be operated. 
         [0013]    It is still another advantage of this invention that the overall thickness of the rear end gear box cover is not appreciably increased compared to the thickness of the known prior art gear box covers. 
         [0014]    It is still another feature of this invention that the gear box cover includes a base plate that is secured to the gear box housing with multiple fasteners, while a removable top plate is secured to the base plate through cam driven connector pins. 
         [0015]    It is yet another feature of this invention that the base plate is formed with receiver mounts that are formed with receiver openings into which the cam driven connector pins are positioned to secure the top plate to the base plate. 
         [0016]    It is yet another advantage of this invention that top plate carries the bearings to support the input and transfer shafts within the rear end gear box. 
         [0017]    It is still another advantage of this invention that both the base plate and top plate are sealed with shaped O-rings, with a first O-ring sealing between the base plate and the rear end housing and the second O-ring sealing between the base plate and the top plate. 
         [0018]    It is still another feature of this invention that the top plate of the rear end gear box cover incorporates a detent mechanism to restrain the cam mechanism, and the connector pins, into the locked engagement with the base plate. 
         [0019]    It is still another advantage of this invention that the rear end gear box cover can be utilized on rear end gear boxes in which the input and transfer shafts are vertically aligned or are offset from one another horizontally. 
         [0020]    It is yet another object of this invention to provide a rear end gear box cover for a racing car which is durable in construction, inexpensive of manufacture, carefree of maintenance, and simple and effective in operation. 
         [0021]    These and other objects, features and advantages are accomplished according to the instant invention by providing a rear end gear box cover for a racing car in which the cover is formed with a fixed base plate and a removable top plate. The base plate is fixed to the rear end housing by multiple fasteners while the top plate is removable from the base plate. The top plate includes a pair of opposing cam members carrying connector pins for engagement with receiver mounts formed on the base plate. A cam driver on the top plate has a central connector member that when rotated drives a pair of opposing cam pins carried in a slotted opening on the cam members outwardly to force the connector pins into openings in the receiver mounts and secure the top plate to the base plate. A detent mechanism in each of the slotted openings retains the cam members in a locked position. A quarter turn of the connector member retracts the connector pins. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: 
           [0023]      FIG. 1  is an end elevational view of a rear end gear box housing representing the known prior art gear box cover used on an offset gear box; 
           [0024]      FIG. 2  is a cross sectional view through the rear end gear box taken along lines  2 - 2  of  FIG. 1  to show the known prior art drive components for transferring rotational power from the engine of the racing car to the rear axle; 
           [0025]      FIG. 3  is a perspective view of the exterior side of the rear end gear box cover incorporating the principles of the instant invention; 
           [0026]      FIG. 4  is a perspective view of the interior side of the rear end gear box cover shown in  FIG. 3 ; 
           [0027]      FIG. 5  is a rear elevational view of the rear end gear box cover according to the principles of the instant invention; 
           [0028]      FIG. 6  is a side elevational view of the rear end gear box cover depicted in  FIG. 5 ; 
           [0029]      FIG. 7  is an exploded view of the rear end gear box cover incorporating the principles of the instant invention; 
           [0030]      FIG. 8  is an enlarged rear view of the rear end gear box cover with the cam members moved into the unlocked position permitting the top plate to be removed from the base plate for access to the interior of the rear end gear box; 
           [0031]      FIG. 9  is a cross-sectional view of the rear end gear box cover corresponding to lines  9 - 9  of  FIG. 8  with the connector pins disengaged from the receiver mounts; 
           [0032]      FIG. 10  is an enlarged rear view of the rear end gear box cover with the cam members moved into the locked position securing the top plate to the base plate; 
           [0033]      FIG. 11  is a cross-sectional view of the rear end gear box cover corresponding to lines  11 - 11  of  FIG. 10  with the connector pins engaged into the receiver mounts; 
           [0034]      FIG. 12  is an enlarged view of the cam members mounted on the top plate with the top cover removed to shown the relationship of the drive pins to the respective cam members positioned in the unlocked position; 
           [0035]      FIGS. 13 and 14  are enlarged detail views of the drive pins received in the slotted openings formed in the cam members corresponding to circles  13  and  14 , respectively; 
           [0036]      FIG. 15  is a perspective view of the cam members as depicted in  FIG. 12 ; 
           [0037]      FIG. 16  is an enlarged detail view of the drive pin within the slotted opening of a cam member corresponding to circle  16  in  FIG. 15 , the detent mechanism being shown in the end of the slotted opening opposite from the location of the drive pin; 
           [0038]      FIG. 17  is an enlarged view of the cam members mounted on the top plate with the top cover removed to shown the relationship of the drive pins to the respective cam members positioned in the locked position; and 
           [0039]      FIGS. 18 and 19  are enlarged detail views of the drive pins received in the slotted openings formed in the cam members corresponding to circles  18  and  19 , respectively, the detent mechanism being shown in engagement with the drive pins to retain the cam members in the locked position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0040]    Referring now to  FIGS. 1 and 2 , a prior art representation of the rear end gear box and cover therefore can be seen. The rear end gear box  10  is typically deployed at the rear axle of a racing car, such as a sprint race car, modified, late model, and/or street rods, or even non-racing vehicles, in which the engine (not shown) is connected directly to the rear end gear box  10 . The rear end gear box  10  is operable to transfer the rotational power from the engine to the rear axle of the racing car to power the movement of the racing car around the race track. The rear end gear box  10  includes a housing  11 , a ring gear cowling  12  having a central opening  13  through which the rear axle passes and is engaged by the ring gear  13   a,  a transfer cowling  14  and a cover  15  on the transfer cowling  14  that is secured to the housing  11  by multiple fasteners  15   a.  The rear axle (not shown) of the racing car passes through the central opening  13  of the ring gear cowling  12  and extends transversely therethrough to drive the rear wheels (not shown) on opposing sides of the racing car. 
         [0041]    The components of the rear end gear box  10  are best seen in  FIG. 2 . The power input shaft  16  is part of the input driveline connected directly to the engine (not shown) and delivers rotational power from the engine into the rear end gear box  10 . The power input shaft  16  has mounted on the rearward end thereof an input gear  17  positioned within the transfer cowling  14 . The rearward end of the power input shaft  16  is rotatably supported by a bearing  16   a  mounted in the cover  15 . The input gear  17  is intermeshed with a transfer gear  18  mounted within the transfer cowling  14  at the rearward end of a transfer shaft  19  which is rotatably supported by a second bearing  19   a  mounted in the cover  15 . The transfer shaft  19  is coupled to the ring gear  13   a  to transfer rotational power to the rear axle (not shown). 
         [0042]    To access the input and transfer gears  17 ,  18  within the transfer cowling, the cover  15  has to be removed, requiring the disengagement of each of the multiple fasteners  15   a  connecting the cover  15  to the housing  11 . Once all of the fasteners  15   a  have been removed, the cover  15  can be pulled off of the ends of the power input shaft  16  and the transfer shaft  19  with the bearings  16   a,    19   a  remaining on the interior of the cover  15 . The input and/or transfer gears  17 ,  18  can then be removed from the ends of the respective shafts  17 ,  19  and replaced as desired. Operational status can be regained by sliding the cover  15  onto the transfer cowling  14  with the bearings  16   a,    19   a  being placed onto the ends of the corresponding shafts  16 ,  19 . The multiple fasteners  15   a  can then be re-engaged into the housing  11 . One skilled in the art will recognize that the rear end gear box  10  shown in  FIGS. 1 and 2  has the power input shaft  16  offset horizontally relative to the transfer shaft  19 ; however, the same cover  15  will also cover the configuration where the power input shaft  16  is vertically aligned with the transfer shaft  19 . 
         [0043]    Referring now to  FIGS. 3-19 , a rear end gear box cover assembly  20  incorporating the principles of the instant invention can best be seen. The rear end gear box cover assembly  20  replaces the prior art rear end gear box cover  15  and provides a secure connection with the housing  11  while enabling a quick removal of the cover assembly  20  from the housing  11 , as will be described in greater detail below. 
         [0044]    The cover assembly  20  has two major components, a base plate  22  and a top plate  30 . The base plate  22  is formed in the same peripheral shape as the prior art cover  15  so that the base plate  22  is secured to the housing using multiple fasteners  24 . However, the thickness of the base plate  22  is less than that of the prior art cover  15 , as the bearings  17 ,  18  are mounted in the top plate  30  and project through the base plate  22  for engagement with the shafts  16 ,  19 , as described above. The combination of the base plate  22  and the top plate  30  is approximately the same overall thickness as the prior art cover  15  so that the cover assembly  20  can replace the prior art cover  15 . The base plate is formed with a central dog bone-shaped opening  23  in the central portion thereof. The base plate  22  is also formed with four receiver mounts  25  that project outwardly from the base plate  22  for engagement by the cam mechanism  40  on the top plate  30 , as will be described in greater detail below. Each receiver mount  25  is formed with a receiver opening  26  that extends parallel to the movement of the cam mechanism  40 . 
         [0045]    The top plate  30  is formed with a bearing mount  32  that is sized to fit within the dog bone-shaped opening  23  in the base plate  22 . The bearings  17 ,  18  are mounted within the bearing mount  32  and are retained therein by a bearing retainer  33 . The top plate  30  also includes four mount openings  35  therethrough and positioned to permit passage of the receiver mounts  25  therein when the top plate  30  is mounted on the base plate  22 . The top plate  30  further includes two pairs of slide pockets  37  formed in the top plate  30  to permit the movement of the cam mechanism  40 , and a central opening  38  into which the cam driver  50  is positioned to operate the cam mechanism  40 . As is shown in the exploded view of  FIG. 7 , the base plate  22  is sealed against the housing  11  by a formed O-ring seal or gasket  29 , while the top plate  30  is sealed against the base plate  22  by a similarly shaped O-ring seal or gasket  39 . 
         [0046]    The cam mechanism  40  is mounted on the top plate  30  for movement along the length of the top plate  30 . The cam mechanism  40  includes a pair of cam members  41  located on opposing sides of the central opening  38  through the top plate  30 . A cam driver  50  is mounted in the central opening  38  and engages each of the cam members  41 , as will be described in greater detail below. Each cam member  41  includes a slidable cam plate  42  having a pair of opposing pin holders  43  positioned respectively in the opposing slide pockets  37 , while the central body portion  44  of the cam plate  42  rides above the top plate  30  so as to be engaged by the cam driver  50 . Each pin holder  43  receives a locking pin  45  that is preferably threaded into the pin holder  43  and secured therein by a bolt  46 . Each locking pin  45  projects outwardly from the pin holder  43  so as to be selectively engaged with the corresponding receiver opening  26  within the receiver mount  25  when the cam members  41  are moved into a locked position. 
         [0047]    The cam driver  50  is formed as a disk member having upper and lower disks  51 ,  52  spaced apart sufficiently to receive the body portion  44  of the cam plates  42 . A pair of opposing driver pins  53  extends between the upper and lower disks  51 ,  52  such that each driver pin  53  passes through the corresponding arcuate slot  47  in the respective cam plates  42 . The cam driver  50  is also formed with a driver head  55  at the center of the upper disk  51 . The driver head  55  can be engaged with a socket wrench (not shown) to cause the cam driver  50  to rotate, as will be described in greater detail below. A cover plate  57  having a central opening  58  therethrough is secured to the outer surface of the top plate  30  by fasteners  59 . The cam driver  50  is mounted for rotation between the top plate  30  and the cover plate  57  such that the upper disk  51  is mounted above the cover plate  57  so that the driver head  55  is readily accessible, while the lower disk  52  is received within the central opening  38  in the top plate  30 . The cam members  41  operate beneath the cover plate  57  and within and above the top plate  30 . An appropriately shaped O-ring  56  seals the lower disk  52  against the top plate  30 . 
         [0048]    The selective rotation of the driver head  55 , such as by an operator applying a socket wrench (not shown) to the driver head  55  and causing the driver head  55  to rotate through a quarter turn of the driver head  55 , results in the rotation of the cam driver  50 . The rotating cam driver  50  causes the driver pins  52  to move along the arcuate slots  47  in the body portions  44  of the cam plates  42 . The orientation of the curved slots  47  pushes the cam plates  42  along the top plate  30  such that the pin holders  43  and the locking pins  45  move along the slide pockets  37 . Assuming that the cam mechanism starts in the unlocked position, as is depicted in  FIGS. 8 ,  9 ,  12  and  15 , the quarter turn of the driver head  55  pushes the locking pins  45  outwardly toward the corresponding receiver mounts  25  which are positioned within the mount openings  35  of the top plate  30 . The locking pins  45  slide into the receiver openings  26  to secure the top plate  30  against the base plate  22 , which in turn is secured to the housing  11  by the multiple fasteners  24 , moving the cam mechanism  40  into the locked position. 
         [0049]    The unlocking of the rear end gear box cover assembly  20  is attained in the reverse manner. The driver head  55  is rotated by an attached wrench or socket (not shown) to rotate the cam driver  50  that pulls the driver pins  52  along the arcuate slots  47  to pull the cam members  41  inwardly toward the cam driver  50 . This movement of the pin holders  43  along the slide pockets  37  pulls the locking pins  45  out of the receiver mounts  25  to permit the top plate  30  to be removed from the base plate  22  and exposing the transfer cowling  14  for access to the drive and transfer gears  17 ,  18 . As noted above, the bearings  16   a,    19   a  remain in the top plate  30  as the top plate  30  is removed from the base plate  22  which remains fixed to the housing  11 . The drive and transfer gears  17 ,  18  are accessible through the central dog bone shaped opening  24  through the base plate  22 . Once the drive and transfer gears  17 ,  18 , or the bearings  16   a,    19   a,  are serviced or replaced, as desired, the top plate  30  can be repositioned on top of the base plate  22  with the ends of the power input and transfer shafts  16 ,  19  received in the corresponding bearings  16   a,    19   a.  The cam driver  50  can then be rotated to push the locking pins  45  back into engagement with the corresponding receiver mounts  25 . 
         [0050]    It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention.