Pneumatic drive

摘要

This relates to a pneumatic drive with a compressed air cylinder (1) and a piston rod (2) moving in order to adjust machine parts. A worm drive (7, 8), the motor-driven worm (8) of which has a length corresponding to the axial stroke of the piston rod (2) and extends parallel to the compressed air cylinder (1), is assigned to the piston rod (2) and the compressed air cylinder (1). The arrangement is so devised that when the compressed air cylinder (1) is acted upon, that is in rapid traverse, the worm (8) is held rotationally fixed by the stationary motor (13) and the worm gear (7) rolls on the worm (8) and that in the transition from rapid traverse to creep speed for accurate postioning the worm gear (7) is locked by a brake device (9-11) and the worm (8) turned by the motor (13), the locked worm gear (7) being driven by a housing (5) and the piston rod (2), connected to it by way of a cross member (3), into the required position. <IMAGE>