Patent ID: 7299671

Claim:
A bending device for bending machine, comprising: a bending die or matrix, mounted on an arm-turning spindle, about which matrix a workpiece is bent, a pressure die or countermatrix, which is hold by its countermatrix-holder support element and is adapted to withstand opposite forces of the workpiece in a bending operation, a die able to prevent wrinkles, which is hold by a die support element so as to face the countermatrix, both the countermatrix and the die able to prevent wrinkles exerting on the workpiece an adequate pressure by a first operating means acting on the countermatrix and a second operating means acting on the die able to prevent wrinkles through said support elements of the countermatrix and the die able to prevent wrinkles before a bend arm, that is fixed around said arm-turning spindle, performs a bending operation by clamping and drawing a section of the workpiece, characterized in that: said countermatrix-holder support element is fixed on an upper slide which is mounted slidable in transversal direction to the workpiece on a lower slide movable in turn in the same direction of the upper slide, on a table; said first operating means comprises: a first double-acting cylinder, being fixed on said lower slide and having a first cylinder piston rod acting on a portion of said countermatrix-holder support element to move the countermatrix toward and away from the workpiece; and a second double-acting cylinder which is slidable on the upper slide and connected to a slider on a counteracting rod being pivoted about an end of said arm-turning spindle, the slider being designed to abut against a first stop on said counteracting rod so that a second cylinder piston rod exerts a force on said countermatrix-holder support element in a projecting portion thereof which is situated beside said portion where the first cylinder piston rod acts; and said second operating means comprises a die slide on which said die support element for a die able to prevent wrinkles is mounted, said die slide being slidable on said table integrally, through connecting means, to said lower slide.