Patent Abstract:
A biasing assembly for a punching device that includes a punch support member adapted to support a punch and including a head portion and a main portion extending from the head portion. The main portion has a recessed surface. A retaining member is coupled to the punch support member with the punch support member being slidable with respect to the retaining member. A coupling member is disposed between the main portion of the punch support member and the retaining member. A portion of the coupling member engages the recessed surface. A biasing member is supported between the head portion of the punch support member and the retaining member. The punch support member is movable between at least first and second positions with respect to the coupling member.

Full Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a biasing assembly for use in a punching device that facilitates adjustment of the punch and remains assembled even after removal of the punch.  
       BACKGROUND OF THE INVENTION  
       [0002]     In conventional high speed punching machines, the cutting end of the punch after a period of use requires sharpening, typically by grinding. Sharpening, however, shortens the punch. To ensure proper positioning after sharpening, the punch must be readjusted. Often conventional punching machines require complete disassembly of their spring assemblies in order to sharpen and adjust the punch. Disassembly of the spring assemblies is time consuming and frequently requires the use of special tools. Moreover, the spring assemblies of conventional punching machines include many parts that require additional labor to assemble.  
         [0003]     Examples of conventional punching machines include U.S. Pat. No. 4,440,052 to Weisbeck; U.S. Pat. No. 4,141,264 to Weisbeck; U.S. Pat. No. 4,092,888 to Wilson; U.S. Pat. No. 3,958,476 to Bartha; U.S. Pat. No. 3,741,056 to Saladin; and U.S. Pat. No. 939,958 to Koelsch; the subject matter of each of which is hereby incorporated by reference.  
       SUMMARY OF THE INVENTION  
       [0004]     Accordingly, an object of the present invention is to provide a biasing assembly for a punching device that remains assembled upon removal of the punch.  
         [0005]     Another object of the present invention is to provide a biasing assembly for a punching device that facilitates adjustment of the punch after sharpening the punch.  
         [0006]     Yet another object of the present invention is to provide a biasing assembly for a punching device that requires a minimal number of parts.  
         [0007]     The foregoing objects are attained by a biasing assembly for a punching device that includes a punch support member adapted to support a punch and including a head portion and a main portion extending from the head portion. The main portion has a recessed surface. A retaining member is coupled to the punch support member with the punch support member being slidable with respect to the retaining member. A coupling member is disposed between the main portion of the punch support member and the retaining member. A portion of the coupling member engages the recessed surface. A biasing member is supported between the head portion of the punch support member and the retaining member. The punch support member is movable between at least first and second positions with respect to the coupling member.  
         [0008]     The foregoing objects are also attained by a biasing assembly for a punching device that includes a punch support member adapted to support a punch and including a head portion and a main portion extending from the head portion and having a recessed surface. The punch support member includes an inner bore adapted to receive a punch. A collar is coupled to the punch support member with the punch support member being slidable with respect to the collar. A ring shaped clip is disposed between the main portion of the punch support member and the collar. The clip engages the recessed surface. A spring is supported between the head portion of the punch support member and the collar. The punch support member is movable between at least first and second positions with respect to the coupling member.  
         [0009]     Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:  
         [0011]      FIG. 1  is a side elevational view in section of a biasing assembly of a punching device in accordance with an embodiment of the invention, showing the biasing assembly of the punching device in a resting position;  
         [0012]      FIG. 2  is a side elevational view in section of the biasing assembly of the punching device illustrated in  FIG. 1 , showing the biasing assembly in a compressed position;  
         [0013]      FIG. 3  is an exploded perspective view of the biasing assembly illustrated in  FIGS. 1 and 2 ;  
         [0014]      FIG. 4  is an enlarged partial view of the biasing assembly of the punching device illustrated in  FIG. 1 , showing a coupling member in one position with respect to a punch support member of the biasing assembly;  
         [0015]      FIG. 5  is an enlarged partial view of the biasing assembly of the punching device illustrated in  FIG. 2 , showing the coupling member in another position with respect to the punch support member; and  
         [0016]      FIG. 6  is a top plan view in partial section of a retaining member of the biasing assembly illustrated in  FIGS. 1 and 2 , showing a passageway extending through the retaining member. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]     Referring to  FIGS. 1-6 , a punching device  10 , such as turret punch press, generally includes a punch  12  for punching a work piece  14 , such as sheet metal, a punch guide  16 , and a biasing assembly  18  that assists in the linear movement of punch  12 . Punch  12  can be removed from biasing assembly  18  and mounted back into assembly  18  without the components thereof disassembling. This allows for easy removal and adjustment of punch  12 , such as when sharpening of the punch  12  is required.  
         [0018]     As seen in  FIGS. 1-3 , biasing assembly  18 , in accordance with the present invention, includes minimal components. In particular, biasing assembly  18 , includes a punch support member  20 , a retaining member  22 , a coupling member  24  coupling the punch support member  20  and the retaining member  22 , and a biasing member  26  disposed between the punch support member  20  and retaining member  22 . A cover sleeve  28  can be provided to cover biasing member  26 , but is not required.  
         [0019]     Punch support member  20  includes a head portion  30  and a main portion  32  extending therefrom forming a generally T-shaped member. A substantially continuous inner bore  34  extends through punch support member  20  between first and second ends  36  and  38  of member  20 . Head and main portions  30  and  32  can either form a one-piece unitary member or be separate pieces attached in any known manner. Head portion  30  is substantially disc-shaped and includes an outer surface  40  that can be knurled. As seen in  FIGS. 1 and 2 , opposite main portion  32 , head portion  30  includes an exposed surface  42  that engages a striker  44  of the punching device  10  for compressing biasing assembly  18  and linearly moving punch  12 . Opposite the exposed surface  42  of head portion  30  is an engaging surface  46  that engages biasing member  26 . An opening  48  of head portion  30  at the first end  36  of punch support member  20  is continuous with inner bore  34 .  
         [0020]     Main portion  32  of punch support member  20  is substantially tubular with an end opening  50  continuous with inner bore  34 . The outer surface  52  of main portion  32  includes a recessed area  54  extending around main portion  32  and that is defined between first and second shoulders  56  and  58 , as seen in  FIGS. 3-5 . The outer surface  52  also includes a stopping area  60  which is substantially flat, as seen in  FIG. 3 .  
         [0021]     As seen in  FIGS. 1-3 , retaining member  22  has a collar shape with a main retaining portion  64 , first and second extensions  66  and  68  extending from opposite sides of main retaining portion  64 , and a generally continuous inner bore  70  ( FIG. 6 ) extending through main retaining portion  64  and extensions  66  and  68 . Main retaining portion  64  is wider than first and second extensions  66  and  68  and includes an engaging surface  72  facing first extension  66  for engaging biasing member  26 , and an opposite guide engaging surface  74  facing second extension  68 , as seen in  FIG. 4 . Main retaining portion  64  preferably receives pins (not shown) of punch guide  16  and abuts punch guide  16  at surface  74 , thereby attaching retaining member  22  to punch guide  16 . However, retaining member  22  can be attached to punch guide  16  in any known manner. An inner radial groove  76  of main retaining portion  64  is formed in the inner surface  78  defined by inner bore  70  for receiving coupling member  24 , as seen in  FIGS. 4 and 5 .  
         [0022]     As seen in  FIG. 6 , a passageway  80  extends from the outer surface  82  of main retaining portion  64  to inner groove  76 . An access opening  84  is provided in outer surface  82 , as seen in  FIG. 3 , to allow coupling member  24  to be inserted into passageway  80  and into inner groove  76 . As seen in  FIG. 3 , first extension  66  of main retaining portion  64  includes a stopping area  86  ( FIG. 6 ) that is substantially flat and cooperates with stopping area  60  of punch support member  20  to limit rotation of retaining member  22  and punch support member  20  with respect to one another and provide a positive lock therebetween.  
         [0023]     As seen in  FIG. 3 , coupling member  24  can be a substantially ring shaped clip with a cut-out section  88  that allows installation of coupling member  24  into retaining member  22 . Coupling member  24  is preferably made of a metal wire but can be formed of any resilient material. Biasing member  26  can be a compression spring, as seen in  FIG. 3 , or any type of biasing structure.  
         [0000]     Assembly and Operation  
         [0024]     Referring to  FIGS. 1-6 , biasing assembly  18  of punching device  10  is assembled in accordance with the present invention by disposing biasing member  26  around main portion  32  of punch support member  20  and between head portion  30  and main retaining portion  64  of retaining member  22 . Main portion  32  of punch support member  20  is slidably inserted through inner bore  70  of retaining member  22  with biasing member  26  abutting engaging surface  46  of head portion  30  and engaging surface  72  of main retaining portion  64 .  
         [0025]     Coupling member  24  is inserted through access opening  84  of main retaining portion  64 , into passageway  80 , and into inner groove  76  of retaining member  22 . A portion of coupling member  24  is disposed in recessed area  54  of main portion  32  of punch support member  20  between shoulders  56  and  58 , as best seen in  FIGS. 4 and 5 . Coupling member  24  abuts first shoulder  56  of recessed area  54 , as seen in  FIG. 4 , thereby substantially preventing disassembly of punch support member  20  and retaining member  22 . Biasing member  26  applies force to both punch support member  20  and retaining member  22 . Stopping surface  60  of main portion  32  of punch support member  20  and stopping surface  86  of first extension  66  of retaining member  22  engage one another. Because both surfaces are substantially flat, punch support member  20  and retaining member  22  are prevented from rotating with respect to one another, thereby providing a positive lock between the two members. As such, no additional fasteners, such as a set screw, are required to lock punch support member  20  and retaining member  22 . Cover sleeve  28  surrounds biasing member  26 .  
         [0026]     Punch  12  is received in inner bore  34  of punch support member  20  and inner bore  70  of retaining member  22  with a first end  90  of punch  12  being threadably engaged with threads  92  of inner bore  34  near head portion  30  of punch support member  20 , as seen in  FIGS. 1 and 2 . An opposite second end  94  of punch  12  extends through guide  16  to punch workpiece  14 , as seen in  FIG. 2 .  
         [0027]     Biasing assembly  18  and punch guide  16  are connected by inserting pins of guide  16  through corresponding holes (not shown) in guide engaging surface  74  of main retaining portion  64  of retaining member  22 . Also, an O-ring  96  disposed around second extension  68  of main retaining portion  64  can be employed to connect guide  16  and assembly  18 . In particular, O-ring  96  engages a groove  98  in guide  16 , as seen in  FIGS. 1 and 2 . However, any known attachment can be used to couple retaining member  22  of biasing assembly  18  and guide  16 .  
         [0028]     During operation, the striker  44  engages exposed surface  42  of head portion  30  of punch support member  20  forcing biasing member  26  to compress, thereby moving punch support member  20  towards guide  16  with the second end  92  of punch  12  punching work piece  14 , as seen in  FIG. 2 . First shoulder  56  of recessed area  54  of punch support member  20  moves away and is spaced from coupling member  24  as biasing assembly  18  is being compressed, as seen in  FIG. 5 . Biasing member  18  can be compressed until coupling member  24  abuts second shoulder  58  of the recessed area  54 . Once work piece  14  has been punched and the striker  44  is released, biasing member  26  forces punch support member  20  back away from guide  16  until coupling member  24  abuts first shoulder  56  of punch support member  20 .  
         [0029]     If second end  92  of punch  12  becomes worn and requires sharpening, punch  12  can be easily removed from biasing assembly  18  and replaced and punch support member  20 , retaining member  22  and biasing member  26  will remain assembled. Punch  12  is simply unscrewed from punch support member  20  and removed from biasing assembly  18 . Punch support member  20 , retaining member  22  and biasing member  26  remain assembled due to coupling member  24 . Punch  12  can then be sharpened and installed back into biasing assembly  18 . Sharpening of punch  12  often reduces the length of punch  12 . The threads  92  of inner bore  34  of punch support member  20  allow for easy adjustment of punch  12  to compensate for the shorter length of punch  12 . Specifically, punch  12  is threaded into the threads  92  of inner bore  34  so that punch  12  meets or is close to work piece  14  prior to being moved by striker  44 , as seen in  FIG. 1 . Punch  12  is adjusted by threading first end  90  of punch  12  into inner bore  34  such that the shorter punch  12  is, the fewer threads  92  of inner bore  34  engage punch  12 .  
         [0030]     While a particular embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modification can be made therein without departing from the scope of the invention as defined in the appended claims.

Technology Classification (CPC): 8