Sprueless plastic material injection molding injection apparatus

Apparatus for the sprueless injection molding of parts from polymers. The apparatus includes an injection mold having a part-forming cavity, and an injection nozzle having a front end cooperating with the mold. A selectively operated closing valve is disposed in the nozzle, the valve having a movable valve member with a valve seat thereon cooperating with a valve seat on the nozzle body. A gate channel or passage is disposed between the valve seat on the body of the nozzle and the inlet opening of the mold cavity. The movable valve member has an elongated forward end portion which is telescoped within the gate passage, the forward end portion sealingly engaging the wall of the gate passage when the valve member is in its forward, closed position, the forward end surface of the elongated forward end portion of the valve member facing the mold cavity lying substantially flush with the wall of the mold when the valve member is in its forward, valve-closed position. The diameter of the forward end surface of the elongated forward end portion of the valve member is less than the smallest diameter of the seats of the closing valve.