Abstract:
The fastener to shaft insertion tool is disclosed which consists of a shaft holding member, a fastener insertion member, and force transmitting member. The fastener holding member facilitates the holding of the fastener and the application of forces to the fastener necessary for its proper insertion onto a shaft. Forces are provided to the fastener holding member by way of a hydraulic or pneumatic actuator. The fasteners are inserted adjacent a ring or gear being coupled to the shaft.

Description:
FIELD OF THE INVENTION 
   This invention pertains to a mechanism for coupling annularly arranged members about a shaft, and more particularly for use as a mechanism to couple gears to a shaft using cir-clips. 
   BACKGROUND OF THE INVENTION 
   Many automotive applications such as gear boxes and axle shafts require the coupling of rings or gears to a shaft. Typically, monolithic tubes or shafts have a plurality of spaced apart cylindrical portions journally mounted onto the shaft. These spaced apart portions are typically coupled to the shaft utilizing methods such as interference fits, welding, and brazing. While these long known methods provide a stable mechanism for the component manufacture, each of these methods have a large potential for off axis deformation of the shaft during the formation process. 
   Additional methods for coupling rings to shafts include inserting coupling pins into the cylindrical portions or immediately adjacent to the cylindrical portions to couple the cylindrical portions. Inserting the coupling pins through the ring may adversely affect the surface of the cylindrical portion as well as the possibility of loosening over time. As such, it is an object of the present invention to overcome the disadvantages associated with prior systems for annularly coupling members to a shaft. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, a coupling tool includes a shaft holding force backup member, an insertion member, and a force transmitting member. A further aspect of the present invention employs a fastener holding member to facilitate the holding of a fastener for the application of forces to the fastener necessary for its proper insertion onto a shaft. In accordance with another aspect of the present invention, the fastener holding member has a fastener holding mechanism, which can take the form of magnets or suction orifices. In accordance with another aspect of the present invention, the fastener holding member further defines a slot, which functions to align the fastener with respect to the shaft. One side of the slot is used to apply forces to the cir-clip to facilitate the joining of the two. The cir-clip holding member translates perpendicular to the shaft to facilitate the joining of the components. 
   In another aspect of the present invention, incorporated into the mechanism is an equalizing “V” type backup. The backup is used to hold the shaft in the proper orientation with the cir-clip holder. Mounted between the backup and the fastener cir-clip holder is a sensor, which measures the distance therebetween. 
   Another aspect of the present invention as shown in the second embodiment of the invention utilizes an actuator which is positioned approximately parallel to the shaft to apply forces. A finger is disposed within the insertion tool and is used to apply the force to the cir-clip. By using an actuator which actuates through a programmed signature as opposed to perpendicular to the shaft, the cir-clip can be inserted into more confined spaces. 
   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 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
       FIGS. 1   a  and  1   b  represent perspective cross sectional views of a preferred first embodiment of the present invention; 
       FIG. 2  represents a top elevational view of the cir-clip insertion mechanism according to the first embodiment of present invention; 
       FIG. 3  represents a side elevational view of the mechanism depicted in  FIG. 2 ; 
       FIGS. 4   a – 4   c  represent the insertion of a cir-clip onto a shaft as depicted in the side cross sectional views of the first embodiment according to the present invention; 
       FIGS. 5   a  and  5   b  depict the disposition and coupling of a ring about the shaft using an alternate embodiment of the present invention; 
       FIG. 6  depicts a top elevational view of the cir-clip insertion mechanism according to the alternate embodiment of the present invention; 
       FIG. 7  depicts a side elevational view of the cir-clip insertion device as shown in  FIG. 2 ; and 
       FIGS. 8   a – 8   d  represent a side elevational view showing the insertion of a cir-clip utilizing the alternate embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     FIGS. 1   a  and  1   b  exhibit disposition and coupling of a ring or gear  10  about a shaft  12 . Ring  10  is annularly disposed about shaft  12 , so that a ring first surface  14  is positioned co-planar to a groove  18  formed on shaft  12 . Ring  10  is axially coupled to shaft  12  by means of a locking cir-clip  20 . Radial rotation of ring  10  about shaft  12  can be regulated by key/slot configurations within the inner diameter  11  of ring  10 . 
   The cir-clip  20 , which is a metal stamped C-shaped semi-circular fastener, is inserted into groove  18  by insertion system  22 . The cir-clip is used to axially fasten a ring  10  onto a shaft  12 . Cir-clip  20  has a first surface  24  that is positioned so as to contact the bottom  26  of groove  18 . Additionally, cir-clip  20  has a surface  27  that is placed in contact with first surface  14  of ring  10  to axially limit the movement of ring  10  along shaft  12 . The ends  28  and  30  of the cir-clip  20  are radially displaced, while cir-clip  20  is being inserted into groove  18  of shaft  12 . Elastic deformation of cir-clip  20  allows cir-clip  20  to expand and close about the diameter of shaft  12  in groove  18 . 
   As seen in  FIGS. 1   a  and  1   b , insertion system  22  includes a drive head  32  and a backup  35 . Drive head  32  functions to hold cir-clip  20  within an annular depression  34 . Annular depression  34  has at least one coupling mechanism  36  to releasably couple cir-clip  20  to drive head  32 , while drive head  32  is inserting cir-clip  20 . 
   The coupling mechanism  36  can take the form of magnets  38  disposed on a coupling surface  40  of annular depression  34 . Further, coupling mechanism  36  can take the form of a pneumatic system  42 , which uses a vacuum to couple cir-clip  20  within annular depression  34 . It is envisioned that any mechanism which releasably couples cir-clip  20  to drive head  32  but which does not interfere with insertion of dr-clip  20  into the shaft  12  is acceptable. 
   Annular depression  34  is defined by a forcing surface  44 , which mates with a driven surface  46  of cir-clip  20 . A relatively constant force is applied through forcing surface  44  by a forcing mechanism  47 . Forcing mechanism  47  is comprised of a controllable fluid actuator which can be either a hydraulic pneumatic actuator or electromechanical actuator  48 , which applies pressure to drive head  32 , through member  50 . Drive head  32  is linearly moved toward groove  18  in a direction generally perpendicular to shaft  12 . 
   Drive head  32  is coupled to a pair of linear shafts  54  and  56 . Linear shafts  54  and  56  allow drive head  32  to apply linear insertion forces to the cir-clip  20  without applying axial forces to shaft  12  which may cause distortion of shaft  12 . Additionally coupled to base  52  is backup  35 , which radially holds shaft  12  in place and transmits equalizing counterforces into shaft  12  to allow insertion of cir-clip  20  into groove  18 . 
   Disposed between drive head  32  and base  52  is a sensor  53 , which functions to measure the movement of drive head  32 . Measurements from sensor  53  are used to determine when the assembly operation is complete. 
     FIG. 3  depicts the insertion system  22  for inserting cir-clips  20  onto shaft  12  according to the teachings of the first embodiment of the present invention. System  22  is shown in a position immediately prior to actuation of the forcing mechanism  47 . Coupling mechanism  38  has been actuated to hold cir-clip  20  into annular depression  34 . Additionally shown is the mounting frame  56  which couples the system  22  to a robotic arm  58 , which is a part of an industrial articulator or gantry robot. 
   Robotic arm  58  allows the system  22  to be brought into place in the correct position once the ring  10  has been disposed about shaft  12 . Further, robotic arm  58  allows the insertion system  22  to be moved away from the shaft to allow disposition of a second ring (not shown) onto shaft  12 . Robotic arm  58  then indexes the insertion system  22  along shaft  12  to allow insertion of the second cir-clip  20  adjacent the second ring. 
     FIGS. 4   a – 4   c  represent actuated in the insertion of the cir-clip  20  onto the shaft  12 . As is best seen in  FIG. 4   a , the actuator  48  applies forces to drive head  32 . Forces from drive head  32  are applied to cir-clip  20  via forcing surface  44  of annular depression  34 . 
     FIG. 4   b  shows actuator  48  applying forces to drive head  32 . Disposed between backup  35  and drive head  32  is shaft  12  to which ring  10  is being coupled. Drive head  32  has been moved from its unengaged positioned  60  to its engaged positioned  62 . Disposed between drive head  32  and top surface  64  of ring  10  is cir-clip  20 . The bottom surface of drive head  32  is configured not to interfere with top surface  64  of ring  10  when drive head  32  is in its engaged positioned  62 . Cir-clip  20  slides along top surface  64  of ring  10  while being inserted. Top surface  64  and coupling surface  40  of annular depression  34 , trap cir-clip  20  and prevents it from being axially displaced while cir-clip  20  is being inserted into groove  18 . 
     FIG. 4   c  shows insertion system  22  being displaced from its engaged position  62  to its unengaged position  60 . After cir-clip  20  has been inserted into groove  18  of shaft  12 , the coupling mechanism  36  releases the cir-clip  20  from drive head  32 . This allows drive head  32  to be retracted from shaft  12  by actuator  48 . 
     FIGS. 5   a  and  5   b  exhibit the disposition and coupling of a ring  82  about shaft  12  using an alternate embodiment of the present invention. The ring  82  is annularly disposed about shaft  12  so that first surface  14  of ring  82  is positioned either coplanar to groove  18  (as seen in  FIG. 5   a ) or off planar (as seen in  FIG. 5   b ). Ring  82  is coupled to shaft  12  by means of locking cir-clip  20 . 
   The cir-clip  20  is inserted into groove  18  by insertion system  70 . Cir-clip  20  has a first surface  24  that is positioned so as to contact the bottom  26  of groove  18 . Additionally, cir-clip  20  has a surface  27  that is placed in contact with first surface  14  of ring  82 . The ends  28  and  30  of cir-clip are radially displaced while cir-clip  20  is being inserted into groove  18  of shaft  12 . 
   As seen in  FIG. 5   a , insertion system  70  includes drive head  32  and backup  35 . Drive head  32  functions to hold cir-clip  20  within the annular depression  34 . Annular depression  34  has at least one coupling mechanism  36  to releasably couple cir-clip  20  to drive head  32 . Further incorporated into drive head  32  is secondary actuator  72 , which is configured to apply additional vertical and horizontal forces to cir-clip  20 . 
   As with the system depicted in  FIGS. 1   a , and  1   b , coupling mechanism  36  can take the form of magnets  38  disposed on a coupling surface  40  of annular depression  34 . Further, coupling mechanism  36  take the form of a pneumatic system  42 , which uses a vacuum to couple cir-clip  20  within annular depression  34 . 
   The annular depression  34  is defined by forcing surface  44 , which mates with driven surface  46  of cir-clip  20 . Force is applied through forcing surface  44  by first forcing mechanism  73 . The first forcing mechanism  73  is comprised of the controllable hydraulic, pneumatic actuator or electromechanical  48 , which applies pressure to drive head  32 , through member  50 . Drive head  32  is linearly moved toward groove  18  in a direction generally perpendicular to shaft  12 . 
   The secondary actuator  72  is configured to apply additional forces to cir-clip  20 . The secondary actuator  72  is formed of a secondary force applying member  74 , which is coupled to a second pneumatic or electromechanical member  76 . The additional forces are used to force cir-clip  20  into an annular slot  78  disposed within upper surface  80  of ring  82 , as shown in  FIG. 5   b . Annular slot  78  allows additional rings or gears (not shown) to be disposed upon ring  82  without having a space between the rings. 
   Drive head  32  is coupled to a pair of linear shafts  54  and  56 . Linear shafts  54  and  56  allow drive head  32  to apply linear insertion forces to cir-clip  20  without applying forces to cir-clip  20  which may cause cir-clip  20  to be dislodged from drive head  32 . Additionally coupled to base  52  is backup  35 , which radially holds shaft  12  in place and transmits counterforces into shaft  12  to allow insertion of cir-clip  20  into groove  18 . 
     FIGS. 6 and 7  depict insertion system  70  for inserting cir-clips  20  onto a shaft  12  according to the teachings of the second embodiment of the present invention. Insertion system  70  shown in a position immediately prior to actuation of the first forcing mechanism  73 . Coupling mechanism  38  has been actuated to hold cir-clip  20  into annular depression  34 . Additionally shown is the mounting frame  56  which couples insertion system  70  to robotic arm  58 . Robotic arm  58  can be used to rotate the insertion mechanism about an axis perpendicular to axis of shaft  12  to apply forces to cir-clip  20  in a non-perpendicular fashion. This allows the system to insert cir-clip  20  into annular slot  78  disposed within upper surface  80  of ring  82 . As with robotic arm  58  depicted in the first embodiment, robotic arm  58  additionally allows insertion system  70  to be brought into place in the correct position once ring  82  has been disposed about shaft  12 . 
     FIGS. 8   a – 8   d  represent actuation stages of the insertion of cir-clip  20  onto shaft  12 . As is best seen in  FIG. 8   a , actuator  48  applies forces to drive head  32 . Forces from drive head  32  are applied to cir-clip  20  via forcing surface  44  of annular depression  34 . 
     FIG. 8   b  shows actuator  48  applying forces to drive head  32 . Disposed between backup  35  and drive head  32  is shaft  12  to which ring  82  is being coupled. Drive head  32  has been moved from its unengaged positioned  60  to its engaged positioned  62 . Disposed between drive head  32  and top surface  64  of ring  82  is cir-clip  20 . The bottom surface of drive head  32  is configured not to interfere with top surface  64  of ring  82  when drive head  32  is in its engaged positioned  62 . Cir-clip  20  slides along top surface  64  of ring  82  while being inserted. Top surface  64  and coupling surface  40  of the annular depression  34 , trap cir-clip  20  and prevent it from being axially displaced while cir-clip  20  is being inserted into groove  18 . 
     FIG. 8   c  shows the actuation of secondary actuator  72 . Secondary actuator  72  is shown applying vertical and horizontal force to cir-clip  20 . Coupled to secondary actuator  72  is a sensor  53 , which functions to measure the movement of secondary actuator  72 . Measurements from sensor  53  are transmitted to a controller (not shown) which regulates the radial position of the robot arm  58  using feed-back control methodologies. By regulating the angle of insertion from insertion system  70  utilizing robotic arm  58  as well as vertical forces, the insertion system  70  can position cir-clip  20  into slots heretofore not previously possible. The shape of the mechanism  72 ,  76  in conjunction with tool/tip  100  prevents the cir-clip from popping out during insertion. 
     FIG. 8   d  shows insertion system  70  being displaced from its engaged position  62  to its unengaged position  60 . After cir-clip  20  has been inserted into grooves  18  of shaft  12 , coupling mechanism  36  releases cir-clip  20  from drive head  32 . This allows drive head  32  to be retracted from shaft  12  by actuator  47 . 
   The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the spirit of the invention are intended to be within the scope of the invention. For example, the mechanism can be adapted to insert deformable straight pins or fasteners adjacent the rings being coupled to the shaft. Additionally, the robotic arm can be programmed to move in complicated trajectories to facilitate the insertion of the fastener onto the shaft in close tolerance situations. Such variations are not to be regarded as a departure from the spirit and scope of the invention.