Abstract: A method and apparatus for determining the thickness of a workpiece or its springback in a press brake is described. The method includes the steps of detecting the deformation or strain in the punch (1) and/or the die (4) during bending, and translating it into an electric signal, by suitable devices located directly on the working parts; possibly amplifying the electric signal by an amplifier (5) and transmitting the signal to a press brake controller (6), which processes the collected data and corrects the angle of the workpiece being bent. The process allows to determine the springback of the bent sheet, thereby increasing processing accuracy.

Abstract: The invention deals with the field of bending presses, and, more precisely, deals with a device for handling the upper table moving along guiding pillars and carrying the punch. For every table guiding pillar, the device provides for a main lever (10) hinged in a point that is substantially axial with its related guiding pillar and whose driving arm (10a) is hinged to means sliding along a rod hinged to the upper table. The lever resisting arm (10b), whose length is approximately 8–10 cm shorter that the driving arm length, rotates a crank (12) connected through an eccentric (13) or a connection rod to a connecting rod (14) that transmits the translating motion to the upper table.