Bending brake machine

Abstract

A bending machine includes a base frame and arms hingedly coupled to the base frame. The arms include a jaw for clamping a workpiece to be bent. The bending machine also includes a shaft including eccentric shaft portions. The eccentric shaft portions couple the arms to the base frames and have a first eccentric axis and a second eccentric axis. The first and second eccentric longitudinal axes are spaced apart such that the arms rotate and translate as the eccentric shaft portions are rotated about the first eccentric axis. The shaft also includes at least one connecting shaft portion that interconnects the eccentric shaft portions.

What is claimed is:  
     
         1 . A bending machine comprising: 
 at least two base frames;    at least two arms hingedly coupled to the at least two base frames, the arms each including a jaw and moveable between a first position wherein the jaws are positioned away from the base frames and a second position wherein the jaws are positioned toward the base frames; and    a shaft comprising at least two eccentric shaft, the eccentric shaft portions coupling the at least two arms to the at least two base frames and having a first eccentric longitudinal axis around which the eccentric shaft portions rotate and a second eccentric longitudinal axis, which runs through the geometric center of the eccentric shaft portions, the first and second eccentric longitudinal axes being spaced apart thereby causing the arms to both rotate and translate as the eccentric shaft portions rotate about the first longitudinal axis, the shaft further comprising at least one connecting shaft portion removably interconnecting the at least two eccentric shaft portions.    
     
     
         2 . The bending machine of  claim 1 , wherein the at least one connecting shaft portion has a first connecting longitudinal axis around which the connecting shaft portion rotates and a second connecting longitudinal axis, which runs through the geometric center of the connecting shaft, the two connecting longitudinal axes being collinear.  
     
     
         3 . The bending machine of  claim 2 , wherein the first eccentric longitudinal axis and the first connecting longitudinal axis are collinear.  
     
     
         4 . The bending machine of  claim 1 , wherein the connecting shaft portion is tubular.  
     
     
         5 . The bending machine of  claim 4 , wherein the eccentric shaft portion includes a tang protruding from an end of the eccentric shaft portion, the tang engaging a slot in the connecting shaft portion.  
     
     
         6 . The bending machine of  claim 5 , further comprising a sleeve receiving the eccentric shaft portion and the connecting shaft portion and surrounding the tang and the slot.  
     
     
         7 . A bending brake machine for bending a workpiece, the bending brake machine comprising: 
 a base frame including a first working beam;    a plurality of eccentric shafts, each eccentric shaft including a concentric portion having a first axis, and an eccentric portion having a second axis spaced from the first axis;    a plurality of sub frame arms, each subframe arm pivotally supported by a respective one of the eccentric shafts and defining a second working beam that cooperates with the first working beam to clamp the workpiece; and    at least one connecting shaft extending between adjacent sub frame arms and removably coupled to the eccentric shafts, wherein the sub frame arms are movable with respect to the base frame in response to rotation of the eccentric shafts and the at least one connecting shaft.    
     
     
         8 . The bending brake machine of  claim 7 , wherein the sub frame arms are pivotable about the second axis to clamp the workpiece, the eccentric shafts and the at least one connecting shaft being pivotally fixed as the workpiece is clamped.  
     
     
         9 . The bending brake machine of  claim 7 , wherein each eccentric shaft includes two concentric portions and the eccentric portion extends therebetween.  
     
     
         10 . The bending brake machine of  claim 7 , wherein the eccentric shafts each include a tang, and wherein each connecting shaft includes a slot formed on at least one end and engageable with a respective tang to couple the connecting shaft and the eccentric shaft.  
     
     
         11 . The bending brake machine of  claim 10 , wherein the tang is formed on the concentric portion.  
     
     
         12 . The bending brake machine of  claim 7 , wherein pivotal movement of the shafts about the first axis adjusts a relative positioning of the first working beam with respect to the second working beam, thereby facilitating the bending of workpieces having different thicknesses.  
     
     
         13 . A method for making a bending brake machine for bending a workpiece, the method comprising: 
 determining a maximum length and thickness of a workpiece to be bent by the bending brake machine;    providing a base frame having a first working beam including a length corresponding to the determined maximum workpiece length;    calculating a required quantity of, and spacing between sub frame arms based upon the determined maximum workpiece length and thickness;    forming a shaft portion including a concentric portion and an eccentric portion for each sub frame arm;    extending each shaft portion through a respective sub frame arm, the eccentric portion of each shaft engaging the sub frame arm;    forming connecting portions having lengths corresponding to the spacing between the sub frame arms;    coupling the connecting portions between the shaft portions to form a single, modular shaft; and    rotatably coupling the shaft to the base frame.    
     
     
         14 . The method of  claim 13 , further comprising providing a tang at an end of each shaft portion and engaging the tang with a slot formed in a respective connecting portion.  
     
     
         15 . The method of  claim 13 , wherein forming the shaft portion comprises machining the concentric portion and the eccentric portion from the same piece of material.  
     
     
         16 . The method of  claim 13 , wherein extending each shaft portion through a respective sub frame arm comprises inserting the eccentric portion of each shaft into a bushing that extends through the sub frame arm.  
     
     
         17 . The method of  claim 13 , wherein rotatably coupling the shaft to the base frame comprises extending the concentric portions of each shaft portion through a pillow block, and mounting the pillow block to the base frame.  
     
     
         18 . A modular shaft for a bending brake machine, the bending brake machine including a base frame having a first jaw and at least two arms hingedly coupled to the base frame and providing a second jaw, the modular shaft comprising: 
 at least two substantially identical eccentric shafts, each eccentric shaft coupling one of the at least two arms to the base frame, each eccentric shaft including an eccentric portion receivable by a respective arm and defining an eccentric axis, and at least one concentric portion extending from the respective arm, rotatably coupleable to the base frame, and defining a concentric axis, the eccentric axis and the concentric axis being spaced from each other; and    at least one connecting shaft coupled to and extending between the concentric portions, the connecting shaft including a central axis that is substantially aligned with the concentric axis, the modular shaft being rotatable about the concentric axis to adjust a relative position between the first jaw and the second jaw.    
     
     
         19 . The modular shaft of  claim 18 , wherein the at least one end of the connecting shaft includes a slot and the eccentric shaft includes a tang, the tang engageable with the slot to couple the connecting shaft and the eccentric shaft.  
     
     
         20 . The modular shaft of  claim 19 , further comprising a sleeve surrounding the tang and the slot to maintain alignment of the eccentric shaft and the connecting shaft.  
     
     
         21 . The modular shaft of  claim 20 , wherein the connecting shaft is substantially tubular.  
     
     
         22 . A system of bending brake machines, each machine having a plurality of arms hingedly coupled to at least one base frame, each arm having an end moveable between a first position away from the base frame and a second position toward the base frame, the arm securing a workpiece between the end and the base frame in its second position, each arm hingedly coupled to the at least one base frame by an eccentric shaft portion defining an eccentric axis spaced apart from a rotational axis around which the eccentric shaft portion rotates, the eccentric shaft portions being interchangeable and being removeably interconnected by connecting shaft portions which define a longitudinal axis which is colinear with the rotational axis.  
     
     
         23 . The system of bending brake machines of  claim 22 , wherein each connecting shaft portion includes two ends, each end being engageable with a tang protruding from an end of the eccentric shaft portion, each connecting shaft portion thereby removeably interconnecting two eccentric shaft portions.  
     
     
         24 . The system of bending brake machines of  claim 23 , further including a sleeve positioned around a joint defined at the location where the connecting shaft portion engages the tang.