Pneumatic drive for a swingable spool holder

摘要

A swingable spool holder for a spool which can be driven on its periphery is controlled by a pneumatic drive device which can swing the spool holder between an operating position and a rest position. A compressed-air line is connected to the pneumatic drive device, and to a control valve which can be moved into two switching positions by a feeler lever which engages the thread which is to be wound up. A throttle valve which is effective in one direction is provided in the compressed-air line, which throttle valve is influenced by pressure in the compressed-air line so that it throttles the compressed-air supply to the pneumatic drive in one switching position of the control valve and, in another switching position, permits the rapid escape of compressed-air from the pneumatic drive device into the compressed-air line. An arrangement cooperable with the pneumatic drive device and an operating rod which acts onto the spool holder effects a no-load stroke of the drive device of a predetermined length before the operating rod is moved by the drive device.