Abstract: In a quick acting clamping device a pair of pressure levers are mounted in a cylindrical housing for displacement between an unclamped position and a clamped position. In the unclamped position the pressure levers extend obliquely to the cylindrical axis of the housing and in the clamped position they extend parallel to the cylindrical axis. Movement of the pressure levers between the clamped and unclamped positions is provided by mounting one end of each of the levers in a pressure piece. The pressure piece is located in a bore in a piston mounted in another bore within the cylindrical housing. The bore in which the piston is mounted extends transversely of the housing, while the bore in the piston extends in the direction of the cylindrical axis of the housing. The housing includes passageways for introducing pressurized hydraulic fluid into the opposite ends of the bore containing the piston.