Punch and die set

Abstract

A punch and die set includes a die including two arms. The two arms and a bottom of the die define a die channel. A punch is sized to be received in the die channel. A rocker element is movably secured to the die. A reduced frictional element is movably secured to the rocker element. The rocker element is movably secured to the die so that the rocker element pivots relative to the die around a pivot point between a centerline of the die channel and at or inside a first of the arms.

I/We claim: 
     
         1 . A punch and die set, comprising:
 a die including two arms, the two arms and a bottom of the die defining a die channel;   a punch sized to be received in the die channel;   a rocker element movably secured to the die; and   a reduced frictional element movably secured to the rocker element, the rocker element being movably secured to the die so that the rocker element pivots relative to the die around a pivot, point between a centerline of the die and at or inside a first of the arms.   
     
     
         2 . The punch and die set as set forth in  claim 1 , wherein:
 the reduced frictional element is a roller that reduces friction against a work piece as the work piece is pushed into the die channel by the punch.   
     
     
         3 . The punch and die set as set forth in  claim 2 , wherein:
 the pivot point is between the centerline of the die channel and a rotational axis of the reduced frictional element.   
     
     
         4 . The punch and die set as set forth in  claim 2 , wherein:
 the reduced frictional element is a bearing that reduces friction against the work piece as the work piece is pushed into the die channel by the punch.   
     
     
         5 . The punch and die set as set forth in  claim 1 , wherein:
 the die includes a pivot protrusion;   the rocker element includes a pivot recess that cooperates with the die pivot protrusion; and   the pivot point is based on the pivot protrusion.   
     
     
         6 . The punch and die set as set forth in  claim 1 , further including:
 a second rocker element secured to the die;   wherein the rocker element is secured to the first arm of the die; and   wherein the second rocker element is secured to a second of the arms of the die.   
     
     
         7 . The punch and die set as set forth in  claim 6 , wherein:
 the rocker element and the second rocker element define a rocker channel as substantially symmetrical.   
     
     
         8 . The punch and die set as set forth in  claim 7 , further including:
 a second reduced frictional element movably secured to the second rocker element, the second rocker element being movably secured to the die so that the second rocker element pivots relative to the die around a second pivot point between the centerline of the die channel and at or inside the second arm.   
     
     
         9 . The punch and die set as set forth in  claim 8 , wherein:
 the reduced frictional element and the second reduced frictional element reduce friction against a work piece as the work piece is pushed into the rocker channel by the punch;   the rocker element pivots around the pivot point and the second rocker element pivots around the second pivot point as the work piece is pushed into the rocker channel by the punch; and   the pivoting of the rocker element and the second rocker element cause the work piece to over-bend to more than a 180° U-shaped channel while the work piece and the punch are in the rocker channel, so that the work piece is bent to about a 180° U-shaped channel after the punch is removed from the rocker channel and the work piece.   
     
     
         10 . The punch and die set as set forth in  claim 1 , further including:
 a spring mechanism movably securing the rocker element to the first arm of the die.   
     
     
         11 . A method of bending a work piece in a punch and die set, the method comprising:
 positioning a work piece above a rocker channel of a die and between the die and a punch;   moving the punch to push the work piece into the rocker channel;   as the work piece is entering the rocker channel, passing the work piece against a reduced frictional element;   as the work piece is entering the rocker channel, pivoting a rocker element relative to the die around a pivot point between a centerline of the rocker channel and at or inside a first arm of the die.   
     
     
         12 . The method of bending a work piece in a punch and die set as set forth in  claim 11 , further including:
 over-bending the work piece beyond about a 180° U-shaped channel while the work piece and the punch are in the rocker channel, so that the work. piece is bent to about a 180° U-shaped channel after the punch is removed from the rocker channel and the work piece.   
     
     
         13 . The method of bending a work piece in a punch and die set as set forth in  claim 12 , further including:
 removing the punch from the rocker channel; and   removing the work piece from the punch and allowing the work piece to return to about a 180° U-shaped channel bend.   
     
     
         14 . The method of bending a work piece in a punch and die set as set forth in  claim 11 , further including:
 as the work piece is entering the rocker channel, pivoting a second rocker element relative to the die around a second pivot point between a centerline of the rocker channel and at or inside a second arm of the die.   
     
     
         15 . The method of bending a work piece in a punch and die set as set forth in  claim 11 , wherein the step of passing the work piece against a reduced frictional element includes:
 rolling a bearing against the work piece.   
     
     
         16 . A punch and die set, comprising.:
 a die including two arms, the two arms and a bottom of the die defining a rocker channel;   a punch sized to be received in the rocker channel;   a first rocker element movably secured to a first of the arms;   a first reduced frictional element movably secured to the first rocker element, the first rocker element being movably secured to the first arm so that the rocker element pivots relative to the die around a first pivot point between a centerline of the rocker channel and at or inside the first arm;   a second rocker element movably secured to a second of the arms; and   a second reduced frictional element movably secured to the second rocker element, the second rocker element being movably secured to the second arm so that the second rocker element pivots relative to the die around a second pivot point between the centerline of the rocker channel and at or inside the second arm.   
     
     
         17 . The punch and die set as set forth in  claim 16 , wherein:
 the respective positions of the first and second pivot points between the centerline and at or inside of the respective arms results in relatively less force required by the punch to push a work piece into the rocker channel.   
     
     
         18 . The punch and die set as set forth in  claim 16 , wherein:
 the first rocker element and the second rocker element define the rocker channel as substantially symmetrical.   
     
     
         19 . The punch and die set as set forth in  claim 16 , wherein:
 the pivoting of the first rocker element causes a first over-bend in the work piece while, the work piece and the punch are in the rocker channel;   the pivoting of the second rocker element causes a second over-bend in the work piece while the work piece and the punch are in the rocker channel;   the first and second over-bends create more than about a 180° over-bend U-shaped channel; and   the first and second over-bends return to first and second bends after the work piece is removed from the rocker channel and the punch to create about a 180° bend U-shaped channel.   
     
     
         20 . The punch and die set as set forth in  claim 19  wherein:
 the first and second bends are substantially symmetrical.