Anti-backflow valve for injection molding machines

Abstract From the Canadian patent

An anti-backflow valve for mounting on the forward end of a plasticating screw of an injection molding machine. The valve includes a rod-like member that extends forwardly of the plasticating screw, and is relatively rotatable therewith. The rodlike member is axially retained in position relative to the screw by a retaining ring that engages with the formed end of the screw and that includes a valve seat. The outwardly extending end of the rod terminates in a stop that is spaced forwardly of the valve seat. An annular sealing ring includes an outer surface that engages the inner surface of the barrel and an inner surface that is radially spaced from the rod-like member to provide a flow …