Pipe-bending press

Abstract

According to the invention a flat metal plate for the manufacture of pipe is first oriented generally horizontally on horizontally spaced and longitudinally extending supports. A longitudinally extending center tool is pressed down against the workpiece between the supports so as to downwardly plastically deform the workpiece while simultaneously a brace body is pressed with an upward force against the plate directly opposite the center tool so as to hold the plate in contact with the center tool. The center tool and brace body are then synchronously displaced downward relative to the supports with the plate clamped between the center tool and brace body.

1 . A method of bending a flat metal plate for the manufacture of pipe, the method comprising the steps of:
 orienting the plate generally horizontally on horizontally spaced and longitudinally extending supports;   pressing a longitudinally extending center tool down against the workpiece between the supports so as to downwardly plastically deform the workpiece while simultaneously pressing a brace body with an upward force against the plate directly opposite the center tool so as to hold the plate in contact with the center tool; and   synchronously displacing the center tool and brace body downward relative to the supports with the plate clamped between the center tool and brace body.   
     
     
         2 . The method defined in  claim 1  wherein the center tool is equidistant between the supports and the brace body is aligned vertically in line with the center tool. 
     
     
         3 . An apparatus for bending a flat metal plate for the manufacture of pipe, the apparatus comprising:
 a frame;   a pair of horizontally spaced and longitudinally extending supports, the plate being oriented generally horizontally on the supports;   a center tool above and generally between the supports;   upper actuator means for pressing the center tool down against the workpiece between the supports so as to downwardly plastically deform the workpiece;   a brace body below and generally between the supports;   lower actuator means for simultaneously pressing the brace body with an upward force against the plate directly opposite the center tool so as to hold the plate in contact with the center tool; and   control means connected to the upper and lower actuator means for synchronously displacing the center tool and brace body downward relative to the supports with the plate clamped between the center tool and brace body.   
     
     
         4 . The apparatus defined in  claim 3  wherein the lower actuator means includes a fluid-actuated piston/cylinder unit and a pressure accumulator connected thereto. 
     
     
         5 . The apparatus defined in  claim 4  wherein the central tool has an arcuate and downwardly convex lower face. 
     
     
         6 . The apparatus defined in  claim 5  wherein the lower face is part cylindrical. 
     
     
         7 . The apparatus defined in  claim 4  wherein the central tool has a transverse width equal generally to a horizontal spacing between the supports.