Abstract: A machine for bending an elongated workpiece extending along a longitudinal axis has a housing and a holder on the housing for retaining the workpiece with its axis nondisplaceable relative to the housing and for advancing the workpiece in a feed direction parallel to the axis. A support defining a mandrel axis transverse to the longitudinal axis and spaced transversely therefrom is displaceable with the mandrel axis on the housing transverse to the longitudinal workpiece axis. A mandrel carried directly on the support is formed with an arcuate groove centered on the mandrel axis. This mandrel carries an inner jaw forming a continuation of the groove and is rotatable therewith on the support about the mandrel axis.

Abstract: A bending machine for imparting bends to metal plates and the like, also called a brake, and provided with a plate holding table and a plate clamping mechanism. The plate is bent by contact with a pivoting apron. In order to provide automatic adjustment of the distance between the front edge of the bending apron and the metal plate to be bent, i.e., to provide a variable radius of curvature during the bending operation, the bending apron is mounted in slides on its pivotal support arms. The motion of the bending apron in its slides is provided by mechanical lead screws or by hydraulic jacks. In one embodiment, the distance of the front edge of the bending apron from the metal plate is controlled so as to balance the torque provided by an electric torque motor and the counter-torque offered by the plate being bent. In another embodiment, the linear motions of the bending apron are controlled to follow a template whose contour defines the desired radius of curvature.