Bobbin doffing device for a yarn winding mechanism - is driven by piston of double acting pneumatic ram

摘要

A bobbin daffing mechanism of a winding mechanism is driven by pref. longitudinal movement of a drive shaft connected to pref. an independent piston located within a cylinder of a ram, the cylinder also pref. incorporating an auxiliary piston mounted on a lay shaft whereby when the cylinder air is introduced through an inlet between the auxiliary piston and a wall within the cylinder the cylinder is moved such that pref. a rubber stop on the lay shaft abuts against a seat in one end of the cylinder, and the independent piston moves until pref. an abutment on the drive shaft engages a stop at the opposite end of the cylinder. In this position the drive shaft maintains the bobbin in the winding position to doft the bobbin air is introduced through an inlet between a second auxiliary piston and the wall to move the cylinder such that the rubber stop disengages from the seat, and this air is then transferred through a vent and an inlet to the space between the end of the cylinder and the independent piston thereby causing longitudinal movement of the drive shaft to doff the bobbin. In certain cases springs may be used to effect movement of the drive shaft or cylinder.