Adjustable injection molding backflow preventer

摘要

A backflow preventer on the end of a plastifying screw for an injection molding apparatus has a housing provided with radial bores which are axially and angularly offset. A pin accessible from the exterior of the housing passes through a radial hole but traversing in a valve member with clearance to permit the stroke of the valve member to be adjusted by selective insertion of the pin in the bores.