Coupling for ejector of injection mould - provides axial and radial play between ejector pin and plate

摘要

A coupling for joining together the ejector pin and ejector plate of an injection moulding machine is constructed as follows: the pin has a smooth forward end with a tapering conical or chamfered portion to provide a lead-in; this smooth, cylindrical front end is followed by a relatively short threaded region, axially shorter than the cylindrical region but of larger core diameter; attached to the ejector plate is a coupling half which engages, with some radial and some axial play, a second coupling half, into which the threaded portion of the pin can engage. This results in some axial and radial play between the ejector pin and ejector plate. The max. possible axial relative movement between the two coupling parts exceeds the axial length of the threaded portion of the pin, so that when the pin and ejector plate move together, the threaded portion of the pin engages the threaded portion of the second coupling part and moves it axially with it. Thus the pin and the ejector plate can follow exactly guided paths with slight play between them, preventing any possibility of jamming. At the same time, the total coupling volume is small.