Sheet metal bending brake with improved hinge

Abstract

A sheet metal bending brake having a frame with a sheet metal support surface. A clamping jaw is movable relative to 'the frame support surface to clamp the sheet metal between the clamping jaw and the frame. The clamping jaw has a linear front edge. An elongated bending arm is pivotally mounted to the frame by an elongated flexible strap having spaced apart edges. One edge of the strap is secured to the bending arm while the other edge of the strap is secured to the frame such that the bending arm extends parallel to and closely adjacent the clamping jaw front edge.

1 - 14 . (canceled)  
   
   
       15 . A bending brake for bending a work piece, the bending brake comprising: 
 a frame    a clamping jaw mounted to the frame for movement between a clamped position and an unclamped position;    a bending arm mounted to the frame for movement between a staged position and an operated position when the clamping jaw is in the clamped position;    a flexible strap supported by the frame and the bending arm for protective receipt of the work piece directly between the flexible strap and the clamping jaw; and    wherein the flexible strap is disposed between the work piece and the bending arm when the bending arm is in the staged position and in the operated position.    
   
   
       16 . The bending brake set forth in  claim 15  wherein movement of the bending arm plastically bends the work piece about the clamping jaw and resiliently flexes the flexible strap about the clamping jaw and the work piece.  
   
   
       17 . The bending brake set forth in  claim 15  further comprising: 
 the clamping jaw having a front edge; and    the work piece having a first edge located stationary to the frame when the clamping jaw is in the clamped position, and an opposite second edge disposed outward from the front edge and carried by the bending arm during the bending operation.    
   
   
       18 . The bending brake set forth in  claim 15  wherein the flexible strap is connected to the bending arm.  
   
   
       19 . The bending brake set forth in  claim 18  wherein the flexible strap is connected to the frame.  
   
   
       20 . The bending brake set forth in  claim 19  further comprising: 
 the flexible strap having a first point and a second point spaced away from the first point; and    wherein the flexible strap is connected to the bending arm at the first point and is connected to the frame at the second point.    
   
   
       21 . The bending brake set forth in  claim 20  wherein the first point is a protrusion received in a groove in the bending arm for locking engagement to the bending arm.  
   
   
       22 . The bending brake set forth in  claim 21  wherein the second point is a protrusion received in a groove in the frame for locking engagement to the frame.  
   
   
       23 . The bending brake set forth in  claim 20  wherein the first point is located beneath the clamping jaw when the bending arm is in the staged position and is located above the clamping jaw when the bending are is in the operated position.  
   
   
       24 . The bending brake set forth in  claim 15  wherein the flexible strap is elastic.  
   
   
       25 . The bending brake set forth in  claim 24  further comprising a second flexible strap that is non-elastic and connected directly between the bending arm and the frame.  
   
   
       26 . The bending brake set forth in  claim 15  wherein the flexible strap is made of polyurethane.  
   
   
       27 . A bending brake for bending a work piece, the bending brake comprising: 
 a frame having a concave semi-cylindrical bearing surface;    a clamping jaw mounted to the frame for movement between a clamped position and an unclamped position;    a bending arm mounted to the frame for movement between a staged position and an operated position when the clamping jaw is in the clamped position, the bending arm having a convex semi-cylindrical bearing surface that opposes the bearing surface of the frame for pivotal movement of the bending arm with respect to the frame.    
   
   
       28 . The bending brake set forth in  claim 27  further comprising a non-elastic flexible strap connected between the bending arm and the frame for limiting movement of the bending arm between the staged and operated positions.  
   
   
       29 . The bending brake set forth in  claim 27  further comprising a bearing sleeve located between the bearing surface of the bending arm and the bearing surface of the frame for reducing friction.  
   
   
       30 . The bending brake set forth in  claim 27  further comprising: 
 the clamping jaw, the frame and the bending arm being elongated and parallel to one another;    the clamping jaw having a longitudinal front edge; and    wherein the work piece projects laterally forward of the front edge.    
   
   
       31 . The bending brake set forth in  claim 30  further comprising: 
 a elongated flexible strap supported by the frame and connected to the bending arm for protective receipt of the work piece directly between the flexible strap and the clamping jaw; and    wherein the flexible strap is disposed between the work piece and the bending arm when the bending arm is in the staged position and in the operated position.    
   
   
       32 . The bending brake set forth in  claim 31  wherein the flexible strap projects laterally forward of the front edge.  
   
   
       33 . The bending brake set forth in  claim 32  wherein the flexible strap is connected to the bending arm at a connection point disposed slightly forward of the front edge.  
   
   
       34 . The bending brake set forth in  claim 32  further comprising the flexible strap having a support surface for supporting the work piece from below when in the staged position.  
   
   
       35 . The bending brake set forth in  claim 34  wherein the support surface is planar when in the staged position and formed elastically about the front edge when in the operated position.