Patent ID: 10751854

Abstract:
The device (1) for locking workpieces on machine tools comprises: —a first hydraulic cylinder (2) inside which at least one piston (3, 4) is inserted slidably along a main line (A); —a second hydraulic cylinder (15) inside which the first hydraulic cylinder (2) is inserted slidably along the main line (A), the feeding of a pressurised hydraulic fluid into a first chamber (8) being designed to apply to the first hydraulic cylinder (2) a primary force (F) that shifts the first hydraulic cylinder (2) from a home position to a second operating position; —an auxiliary chamber (28) provided between the first hydraulic cylinder (2) and the second hydraulic cylinder (15) and associated with pneumatic feeding means (29, 30, 31) designed to feed pressurised air into the auxiliary chamber (28), the feeding of the pressurised air applying to the first hydraulic cylinder (2) an auxiliary force (Fa) along the main line (A) in the same direction as and operating in conjunction with the primary force (F).