Release of Threaded Moldings in Injection Molding.

This report describes how molds for moldings with threaded holes can be given simpler design by injecting into the parting line and by using a hydraulic screw-out unit which was developed by a mmanufacturer of injection molding machinery as a universal device for releasing moldings with threaded holes. The screw-out unit consists of a hydromotor with infinitely variable speed, two switches, a scaled disc with control cams for setting the required revolutions, a fastening plate with two clamping studs as well as the electrical and hydraulic connections. Designs of several molds with device described are included and their operation is explained. Advantages of the screw-out units are pointed out.