Wedge Driven Pipe Bending Machine

Abstract

A pipe bending machine has a stiff-back which is driven by a pivoting wedge. A linkage applies force from the actuator to the wedge in a direction parallel to a longitudinal axis of the stiff-back. The stiff-back pivots on a first fulcrum and the wedge slides on a bed which pivots on a second fulcrum. The actuator drives the wedge between the stiff-back and the bed to rotate the stiff-back at the first fulcrum and bend the pipe seated in the stiff-back against the pipe bending face of a die. The conversion of the longitudinal force applied to the wedge into a transverse force applied to the stiff-back provides a significant mechanical advantage which varies directionally as the stiff-back rotates about its fulcrum to maintain a constant force on the stiff-back.

What is claimed is: 
     
         1 - 6 . (canceled) 
     
     
         7 . A method for bending pipe comprising the steps of:
 positioning the pipe in a trough extending longitudinally downstream of a die for application by the die of a first force to one side of the pipe;   exerting a second force in a direction parallel to a longitudinal axis of the portion of the pipe positioned in the trough;   converting the second force into a third force applied to the longitudinal trough the pipe on an opposite side of the pipe than and downstream of the first force to bend the pipe against the first force; and   maintaining the third force perpendicular to the longitudinal axis of the portion of the pipe positioned in the trough as the pipe is bending against the die.   
     
     
         8 . A method according to  claim 7  further comprising the steps of:
 repositioning the pipe for application of the first force downstream of the previous application of the first force; and 
 repeating the previous steps. 
 
     
     
         9 . A method according to  claim 7 , said step of maintaining the third force perpendicular to the longitudinal axis of the portion of the pipe positioned in the trough comprising the sub-steps of:
 maintaining the second force parallel to the longitudinal axis of the portion of the pipe positioned in the trough as the pipe is bending against the die; and   maintaining the third force perpendicular to the second force.   
     
     
         10 - 13 . (canceled)