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 . A machine for bending pipe comprising:
 a die;   a trough pivoted on a first fulcrum;   a bed pivoted on a second fulcrum;   a wedge disposed between said trough and said pivoted bed; and   an actuator driving said wedge between said trough and said bed to bend a pipe seated in said trough against said die.   
     
     
         2 . A machine according to  claim 1  further comprising a linkage applying force from said actuator to said wedge in a direction parallel to a longitudinal axis of said trough. 
     
     
         3 . machine for bending pipe longitudinally transferred therethrough comprising:
 a fixed die having a pipe bending face;   a trough pivoted on a first fulcrum about a first axis parallel to said pipe bending face and perpendicular to a longitudinal axis of the pipe;   a bed pivoted on a second fulcrum about a second axis parallel to said first axis;   a wedge disposed between said trough and said pivoted bed; and   an actuator driving said wedge between said trough and said bed to rotate said trough in relation to said first fulcrum and bend a pipe seated in said trough against said pipe bending face of said die.   
     
     
         4 . A machine according to  claim 3  further comprising a linkage applying force from said actuator to said wedge in a direction parallel to a longitudinal axis of said trough as said trough longitudinal axis rotates in relation to said first fulcrum. 
     
     
         5 . A machine for bending pipe longitudinally transferred therethrough comprising:
 a fixed die having a pipe bending face on a downstream portion thereof;   a trough pivoted on a first fulcrum downstream of an upstream portion of said pipe bending face about a first axis parallel to said pipe bending face and perpendicular to a longitudinal axis of the pipe;   a bed pivoted on a second fulcrum downstream of said first fulcrum about a second axis parallel to said first axis;   a wedge disposed between said trough and said pivoted bed; and   an actuator driving said wedge between said trough and said bed to rotate said trough in relation to said first fulcrum and bend a pipe seated in said trough against said pipe bending face of said die.   
     
     
         6 . A machine according to  claim 5  further comprising a linkage applying force from said actuator to said wedge in a direction parallel to a longitudinal axis of said trough as said trough longitudinal axis rotates in relation to said first fulcrum. 
     
     
         7 - 13 . (canceled)