Injection molding valve member with head and neck portions

In a valve gated injection molding apparatus to convey melt to a gate extending through a mold to a cavity comprising a heated nozzle seated in the mold, the nozzle having a rear end, a front end, and a melt bore extending therethrough from the rear end to the front end in alignment with the gate, an elongated valve member having a front end mounted to extend centrally in the melt bore through the nozzle, and valve member actuating means connected to the valve member whereby the valve member is reciprocated between a retracted open position wherein the melt flows from the melt bore through the gate into the cavity and a forward closed position wherein the front end of the valve member is seated in the gate, the improvement wherein;

• the elongated valve member has a cylindricaI stem portion, a short cylindrical head portion with a uniform diameter at the front end, and a neck portion extending rearwardly from the head portion to the cylindrical stem portion, the stem portion having a diameter at least as large as the cylindrical head portion and the neck portion being substantially smaller in cross-sectional area than the head portion.