In commercially available presses, hydraulic or pneumatic systems are used to produce the required pressing force, said systems comprising cylinders which act on a pressure element such as a lifting plate to produce e.g. selective shaping of a metal sheet.
Presses are also known which have an electrically actuated die cushion, in particular an electrically actuated lifting plate. For electrically actuated die cushions, particularly electrically actuated lifting plates, the hydraulic system is replaced by spindles which are actuated by a servo drive. In this drive system, the pressing force must be detected by pressure sensors. Servo drives with reduction gearing or direct drives without gearing are used here. Such a press is known from the printed article “Auf das Tempo kommt es an”, Blech 7-05, pages 30 to 32.
USPTO Backgrounds
USPTO Backgrounds