Abstract:
A puller for removing a pulley off of the shaft is disclosed. The puller may have proximal and distal plates that are disposable around the pulley so that the pulley is disposed entirely between the proximal and distal plates. These plates are held together by frame members. A push rod is threadably engaged to a proximal plate and operative to be further inserted into the proximal plate so that a distal end of the push rod may push against the shaft and transfer a removing force through the puller to the backside of the pulley for removing the pulley off of the shaft.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT 
     Not Applicable 
     BACKGROUND 
     The various embodiments and aspects discussed herein relate to a puller for removing a pulley off of a shaft. 
     In an automobile engine, a number of pulleys are mounted to a shaft and utilized to transfer rotational motion from a first shaft to a second shaft. The first and second shafts are connected to each other with the belt. After a period of time, the pulley must be replaced or fixed. To do so, the pulley must be removed from the shaft. However, due to the tight spacing requirements of the engine, it is often difficult to remove the pulley without significant labor and expense. In certain instances, a number of other parts must be removed before the pulley to be fixed or replaced can be removed from the shaft. 
     Accordingly, there is a need in the art for an improved puller for removing a pulley off of a shaft. 
     BRIEF SUMMARY 
     A puller having proximal and distal plates and frame members that hold the proximal and distal plates together is disclosed. The distance between the proximal and distal plates may be adjusted so that the pulley may be disposed entirely between the proximal and distal plates during the removal process. A push rod is threadably engaged to a proximal plate and centered with respect to the frame members. The push rod engages the shaft as the push rod is rotated into the proximal plate. In this manner, force is transferred from the push rod to the proximal plate, through the frame members and the distal plate and ultimately to a distal end of the pulley. 
     More particularly, a puller for removing a pulley mounted to a shaft of a supercharger is disclosed. The puller may comprise a distal plate, a proximal plate, elongate frame members and a push rod. The distal plate may have an opening sufficiently large to receive the shaft and a portion of the super charger where the shaft is mounted to the portion of the supercharger. The opening may be smaller than a distal end of the pulley so that the distal plate can engage the distal end of the pulley to apply a force to the distal end of the pulley. The first plate may have three attachment points disposed about a central axis of the puller. 
     The proximal plate may have three attachment points disposed about the central axis of the puller. The attachment points of the proximal plate may be in alignment with the attachment points of the distal plate. The proximal plate may have a threaded hole axially aligned to the central axis of the puller. 
     The three elongate frame members may define distal and proximal end portions. The distal end portions of the three frame members may be attached (e.g., threaded engagement) to the three attachment points of the distal plate. The proximal end portions of the three frame members may be attached (e.g., sliding engagement) to the three attachment points of the proximal plate. 
     The push rod may be threadably engaged to the threaded hole of the proximal plate. The push rod may have a wrench engaging portion for rotating the push rod and a distal portion sized and configured to engage a proximal end of the shaft of the supercharger. 
     In use, clockwise rotation of the push rod traverses the distal portion of the push rod into engagement with the proximal end of the shaft of the super charger and creates an opposing force on the distal end of the pulley with the distal plate to pull the pulley off of the shaft of the super charger. 
     The distal and proximal plates may each have three attachment points spaced apart 120 degrees about the central axis. The distal and proximal plates may have two, four or more attachment points spaced apart equally about a central axis of the puller. 
     The frame members may be bolts. The attachment points of the distal plate may be threaded holes engaging a threaded portion of the bolts. The attachment points of the proximal plate are through holes engaging a neck portion of the bolts. One of the frame members closest to the opening of the distal plate may be removably attachable to the distal plate. 
     The threaded hole of the proximal plate may comprise a recess formed on a distal side of the proximal plate and an insert with the threaded hole. The insert may be retained within the recess. 
     The distal portion of the push rod may be independently rotatable with respect to the wrench engaging portion. 
     In another aspect, a method of removing a pulley mounted on a shaft of a supercharger is disclosed. The method may comprise the steps of inserting the pulley between proximal and distal plates of a puller; inserting the shaft and a portion of the supercharger where the shaft is mounted into an opening of a distal plate of the puller; rotating a push rod attached to a proximal plate of the puller; engaging a distal portion of the push rod with a proximal end of the shaft; and pushing the pulley off of the shaft with the distal plate. 
     In the method, the pushing step may include the step of applying a force to a distal end of a body of the pulley to remove the pulley off of the shaft. 
     The method may further comprise the steps of removing an elongate frame member from the distal plate of the puller; and attaching the removed frame member onto the distal plate of the puller. 
     The method may also further comprise the step of maintaining a distal portion of the push rod in a stationary position when the distal portion of the push rod is in contact with the shaft and a threaded portion of the push rod is being rotated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which: 
         FIG. 1  is a perspective view of a supercharger with a pulley mounted to a shaft of the supercharger; 
         FIG. 2  is a perspective view of a puller for removing the pulley mounted to the shaft of the supercharger shown in  FIG. 1 ; 
         FIG. 3  is a perspective view of the puller and the supercharger wherein the puller is mounted to the pulley to be removed; 
         FIG. 4  is a side view of the pulley shown in  FIG. 2 ; and 
         FIG. 5  is an exploded perspective view of the pulley shown in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, a puller  10  for removing a pulley  12  off of a shaft  14  of the supercharger  16  is shown. The puller  10  may have proximal and distal plates  18 ,  20 . The pulley  12  is placed between the proximal and distal plates  18 ,  20 . The distal plate  20  engages a distal end  22  of the pulley  12 . A pushrod  24  is threadably engaged to the proximal plate  18  so that upon rotation of the pushrod  24 , a distal portion  26  of the pushrod  24  pushes upon the shaft  14  of the supercharger  16  which in turn applies a force to the distal end  22  of the pulley  12  with the distal plate  20  to remove the pulley  12  off of the shaft  14 . 
     More particularly, the proximal and distal plates  18 ,  20  may be spaced apart and positioned parallel to each other. The distal plate  20  may have a C-shaped configuration defining an opening  28 . The inner periphery  30  of the opening  28  is smaller than the outer periphery  32  of the pulley  12 , whereas an outer periphery  34  of the distal plate  20  is larger than the outer periphery  32  of the pulley  12 . In this manner, the distal end  22  of the pulley  12  can engage a proximal side  36  of the distal plate  20  during removal of the pulley  12  from the shaft  14 . 
     The distal plate  20  may be configured to fit behind the pulley  12  when the pulley  12  is mounted to the shaft  14  of the supercharger  16 . In particular, the inner periphery  30  of the distal plate  20  may be configured to fit around a portion of the supercharger  16  holding the shaft  14 . As shown in  FIG. 3 , the portion of the supercharger  16  holding the shaft  14  may have a ridge  38 . The ridge  38  may protrude out from the normal envelope of the supercharger  16 . To accommodate the ridge  38 , the distal plate  20 , and more particularly, the inner periphery  30  of the opening  28  of the distal plate  20  may have a cutout  40  for accommodating the ridge  38  so that the proximal side or surface  36  of the distal plate  20  may support the distal end  22  of the pulley  12 . Other configurations of the inner periphery  30  of the opening  28  are also contemplated for the purposes of accommodating other features of a part that holds the shaft  14  on which the pulley  12  is mounted to. 
     The distal plate  20  may also have two or more attachment points  42 . Preferably, the distal plate  20  has three attachment points  42 . The attachment points  42  may be threaded holes  54 . The threaded holes  54  receive elongate frame members  44  (e.g., threaded bolts). The threaded holes  42  engaged the threaded portions of the threaded bolts  44 . The threaded bolts  44  space the proximal and distal plates  18 ,  20  from each other so that they  18 ,  20  remain parallel to each other at a set distance apart from each other during the removal of the pulley  12  off of the shaft  14 . 
     The proximal plate  18  may have two or more attachment points  46  which are through holes  46  formed in the proximal plate  18 . Preferably, the proximal plate  18  has the same number of attachment points  46  as the number of attachment points  42  on the distal plate  20 . The threaded bolts  44  are fed through the through holes  46  then threadably engaged to the threaded holes  42  formed in the distal plate  20 . The proximal plate  18  is capable of sliding along the length of the bolts  44 . The threaded bolts  44  are tightened so that the distance  48  between the proximal side  36  of the distal plate  20  and the distal side  50  of the proximal plate is greater than a height  52  of the pulley  12 . More particularly, the distance  48  between the proximal side  36  of the distal plate  20  and the distal side  50  of the proximal plate  18  is sufficiently large so that (1) the pulley  12  may fit between the proximal and distal plates  18 ,  20 , (2) the distal portion  26  of the push rod  24  can engage the shaft  14  and (3) a threaded hole  54  of the proximal plate  18  may fully engage threads  56  of the pushrod  24 . This means that the distal portion  26  of the push rod  24  is pushed past the threaded hole  54  of the proximal plate  18 . 
     The threaded hole  54  formed in the proximal plate  18  are formed with a recess  58  in the distal side  50  of the proximal plate  18 . 
     The recess  58  is configured to fit a nut  60  which has threads. The nut  60  may be secured in the recess  58  by way of interference fit, welding, adhesive and other attachment methods known in the art or developed in the future. The nut  60  may also have a flange  61  that fits into a corresponding recess  63  formed in the distal side of the proximal plate  18 . The recess  63  that fits the flange  61  is shown in  FIG. 4 . An outer diameter of the flange  61  may have an interference fit with an inner diameter of the recess  63  to secure the nut  60  to the proximal plate  18 . 
     The proximal side of the proximal plate  18  may have one or more mounts  62 . These mounts  62  may receive a wrench or breaker bar  64  to hold the puller  10  stationary as the user rotates the push rod  24  in the clockwise direction  66  for pulling the pulley  12  off of the shaft  14 . As a user rotates the push rod  24  in the clockwise direction, the user also holds and applies a counterclockwise force  68  to the breaker bar  64 . The mount  62  may have a hexagonal configuration so that a wrench with an elongate handle may be utilized as the breaker bar  64 . The mount  62  may have other configurations such as square and other shapes to fit other types of wrenches that grip onto the exterior surface of the mount  62 . The mount  62  may also have a recess on its proximal side sized and configured to receive a hexagonal wrench or other type of wrenching tools. 
     The distal and proximal plates  20 ,  18  may be spaced apart and placed in parallel position to each other with elongate frame members  44 . The frame members  44  may be bolts. The bolts  44  are slid through the holes  70  of the proximal plate  18  and threadably engage to the threaded holes  72  of the distal plate  20 . A length  74  of the bolt  44  may be sufficiently long so that the pulley  12  may be fully disposed between the distal and proximal plates  20 ,  18  and also to allow for full threaded engagement between the threads  56  of the push rod  24  and the threaded holes  54  formed in the proximal plate  18 . This would also allow for the distal portion  26  of the push rod  24  to be fully disposed between the proximal and distal plates  18 ,  20 . A length  76  of the threads of the bolt  44  is sufficiently long to engage the threaded hole  72  formed in the distal plate  20  and to also adjust the distance  48  between the proximal and distal plates  18 ,  20 . The attachment points  42 ,  46  are disposed about a central axis  78 . In the figures, three attachment points  42 ,  46  are formed on the distal and proximal plates  20 ,  18 . These three attachment points  42 ,  46  are angularly spaced apart from each other 120°. It is also contemplated that only two attachment points  42 ,  46  or four or more attachment points  42 ,  46  may be incorporated into the puller  10 . If only two attachment points  42 ,  46  are incorporated into the puller  10 , then the attachment points  42 ,  46  are positioned 180° from each other about central axis  78 . When three or more attachment points  42 ,  46  are incorporated into the puller  10 , then the attachment points  42 ,  46  are angularly spaced apart from each other about the central axis  78  in equal angles. By way of example and not limitation, three attachment points  42 ,  46  are separated from each other at 120° from each other. Four attachment points  42 ,  46  are separated from each other at 90° from each other. 
     The push rod  24  pushes upon the shaft  14  holding the pulley  12 . As the push rod  24  is threaded into the threaded hole  54  of the proximal plate  18 , force is transferred from the push rod  24  to the proximal plate  18 , through the frame members  44 , to the distal plate  20  and places a force on the distal end  22  of the pulley  12  to force the pulley  12  off of the shaft  14 . The push rod  24  may include three components, namely, a threaded portion  80  and the distal portion  26 . The distal portion  26  is allowed to rotate independently from the threaded portion  80  so that the distal portion  26  may remain stationary (i.e., not rotating) when the distal portion  26  is engaged to the shaft  14  of the supercharger  16  and the user is rotating the threaded portion  80  of the push rod  24  to further engage the threads  56  of the threaded portion  80  of the push rod  24  into the threaded hole  54  of the proximal plate  18 . To this end, the threaded portion  80  may have a recessed cavity  82  formed in the distal end portion of the threaded portion  80  of the push rod  24 . A ball bearing  84  may be disposed within the recess cavity  82 . The distal portion  26  may have a protrusion  86  that also is received into the recess cavity  82 . The ball bearing  84  may rest on the proximal end  88  of the protrusion  86  of the distal portion  26  and an inner end  90 . The proximal end  80  and the inner end  90  of the distal portion  26  and the threaded portion  80  are both flat and parallel to each other so that the ball bearing  84  makes a point contact with each of the ends  88 ,  90 . The distal portion  26  has a smaller surface area to the ball bearing  84  compared to the distal end  92  of the distal portion  26  to the shaft  14 . As such, when the user rotates the threaded portion  80  in the clockwise direction  66 , the distal portion  26  remains stationary on the shaft  14 . 
     To remove the pulley  12  from the shaft  14 , the user mounts the puller  10  onto the pulley  12 . To do so, the user removes one of the frame members  44  to make space so that the pulley  12  may be disposed between the distal and proximal plates  20 ,  18 . Preferably, one of the frame members  44  closest to the opening  28  formed in the distal plate  20  is removed. In particular, the threads of the frame member  44  may be disengaged from the threaded hole  72  formed in the distal plate  20 . The disengaged frame member  44  may be slid out completely or at least partially to allow for the puller  10  to be disposed over the pulley  12 . Once the puller  10  is disposed over the pulley, as shown in  FIG. 3 , the threads of the frame member  44  are reengaged to the threaded hole  72 . The engagements of the threads of the frame members  44  to the threaded holes  70  are adjusted so that the proximal plate  18  is parallel to the distal plate  20  during the removal process. In particular, a lower side  94  of a bolt head  96  of the frame members  44  are all disposed within the same plane. 
     The push rod  24  shown in  FIG. 4  may be rotated in the clockwise direction  66  to force the push rod  24  further into the proximal plate  18  so that the distal portion  26  engages the shaft  14  of the supercharger  16 . Preferably, when the distal portion  26  contacts the shaft  14 , the threads of the threaded portion  80  of the push rod  24  are fully engaged to the threads of the threaded holes  54  of the proximal plate  18 . As shown in  FIG. 4 , the length  48  between the proximal side  36  of the distal plate  20  and the distal side  50  of the proximal plate  18  is equal to or greater than the height  52  of the pulley  12  and a length  96  of the distal portion  26  of the push rod  24 . 
     The user places the breaker bar  64  on one of the mounts  62  and begins to rotate the push rod  24  in the clockwise direction  66  to push the distal portion  26  into the shaft  14 . The push rod  24  may be rotated in the clockwise direction  66  by engaging a wrench or other torque producing tool onto a head  98  of the push rod  24 . The breaker bar  64  keeps the puller  10  stationary as the wrench turns the push rod  24 . The initial stages of removing the pulley  12  from the shaft  14  may be difficult. However upon initial movement of the pulley  12  off of the shaft  14 , it is significantly easier to move the pulley  12  off of the shaft  14 . As such, after the initial movement of the pulley  12  off of the shaft  14 , the user may remove the breaker bar  64  from the mount  62  and use his or her hand to keep the puller  10  stationary by gripping the frame members  44 . The user continues to rotate the push rod  24  until the pulley  12  is completely off of the shaft  14 . The thread direction of the threaded portion  80  may also be reversed in that instead of following the right-hand rule, the threads of the threaded portion  80  of the push rod  24  follows the left-hand rule. In particular, the push rod  24  is further inserted into the threaded hole  54  of the proximal plate  18  by rotating the threaded portion in the counterclockwise direction. 
     It is also contemplated that the in-use body of the pulley  12  which is attached to a shaft mount may be replaced with a sacrificial body having a wider distal end  22 . In particular, the body of the pulley  12  may be attached to a shaft mount with a plurality of bolts. The shaft mount may be secured to the shaft  14 . The body is removably attachable to the shaft mount without removing the shaft mount from the shaft  14 . The original, in use, body is removed from the shaft mount by removing the fasteners. The original body is removed and the sacrificial body is then mounted to the shaft mount. The sacrificial body need only have two or more holes in the body for bolting the body to the shaft mount and also the wider distal end  22  in the form of a wider flange. This provides additional leeway or tolerance so that the distal plate  20  may engage the distal end  22  of the pulley  12  in removing the pulley  12  off of the shaft  14 . The sacrificial body is used for the purposes of removal only so that the aesthetically pleasing in-use body of the pulley  12  is not damaged during the pulley  12  removal process. The pulley  12  shown and described in relation to the puller  10  is a two part pulley  12 . However, the puller  10  may also be used to remove a one part pulley. Additionally, the puller  10  may be used to pull larger and smaller pulleys provided that the puller is sized accordingly. 
     The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including various ways of configuring the proximal an distal plates to accommodate the body of the supercharger. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.