Abstract: A bending machine for forming bends in a sheet material. The bending machine has a pair of spaced relatively fixed forming tools for movement with respect to an unclamped portion of the sheet material to effect corresponding bends in the sheet material.

Abstract: A method is disclosed for sensing the position of a workpiece clamp on a workpiece positioning assembly of a computer-controlled machine tool such as a turret punch press including an X-axis traverse, a Y-axis traverse and, a workpiece support movable along the X-axis traverse and carrying the workpiece support. The method consists of the steps of providing a datum position on the X-axis for the control, providing a datum position on the Y-axis for the control, providing a datum position on the turret for the control, moving the member to the datum position on the X-axis at the beginning of each operating sequence, registering movement of the member along the X-axis traverse, moving the member passed sensor means to identify for the control the position of the member relative to the datum position on the X-axis. Apparatus for carrying out the method is also provided.