Method of use for pneumatically operated mold ejection apparatus

摘要

Provided is a method of use of a pneumatically operated mold ejection apparatus using a pneumatic pressure source of conventional means exterior to a multiplate injection molding tool. The pressure source is selectively activated using the mold cycle to operate at least one knock-out pin disposed within the molding plate, usually the cavity plate. The knock-out pin is connected to a pneumatic piston which is urged by biasing means to a stop such that the knockout pin is positioned flush with the inner wall of the molding surface or cavity during injection of plastic or other molding material into the tool. The side of the molding plate opposite the molding surface is characterized by at least one pneumatic channel between the piston and its intersection with a complimentary pneumatic channel in a backing plate. The latter is perforated by a pneumatic orifice for connection of the system to the external pneumatic pressure source. The pneumatic channel of the molding plate and complimentary pneumatic channel of the backing plate are surrounded by a perimeter groove in which is disposed an O-ring to optimize sealing against leakage of the compressed air from between the molding plate and adjacent backing plate.