Abstract: A shutoff nozzle body and valve assembly operative to reduce molten plastic resin drool when the nozzle body is separated from the mold or runner system. The apparatus includes a porting system that shuts off the flow of resin through the sprue plunger of the valve nozzle body before the valve body seals on the valve seat so as to permit any resin that is within the sprue passages to drain out through the sprue plunger into the mold cavity or runner system before the sprue tip completely withdraws from the mold or runner system thereby eliminating drool.

Abstract: A shutoff nozzle body and valve assembly operative to reduce molten plastic resin drool when the nozzle body is separated from the mold or runner system. The apparatus includes a porting system that shuts off the flow of resin through the sprue plunger of the valve nozzle body before the valve body seals on the valve seat so as to permit any resin that is within the sprue passages to drain out through the sprue plunger into the mold cavity or runner system before the sprue tip completely withdraws from the mold or runner system thereby eliminating drool.

Abstract: A shutoff nozzle and valve assembly for gas-assisted injection molding having a nozzle body, a shutoff pin, a helical spring, a spring guide and a gas-injection valve assembly. The shutoff nozzle and valve assembly is a simple design including minimal components, thereby resulting in ease of maintenance and reduced cost. The nozzle assembly is self-actuating, using direct resin pressure to open the valve thereby enabling the flow of molten resin through the nozzle and into a mold cavity. After injection of the molten resin, the helical spring automatically engages the shutoff pin thereby closing the nozzle and valve assembly to prevent backflow. The gas-injection valve assembly is similarly self-actuating such that minimal operator supervision is required to operate the nozzle assembly.

Abstract: A nozzle assembly for gas-assisted injection molding having a nozzle body, a shutoff pin, a helical spring, a spring guide and a gas-injection valve assembly. The nozzle assembly is a simple design including minimal components, thereby resulting in ease of maintenance and reduced cost. The nozzle assembly is self-actuating, using direct resin pressure to open the nozzle assembly, thereby enabling the flow of molten resin through the nozzle and into a mold cavity. After injection of the molten resin, the helical spring automatically engages the shutoff pin thereby closing the nozzle assembly to prevent backflow. The gas-injection valve assembly is similarly self-actuating such that minimal operator supervision is required to operate the nozzle assembly.

Abstract: A rotary flow control valve including a valve spool which is rotated back and forth to move a port in the valve spool into and out of alignment with the main fluid passageway of the valve to selectively open and close the valve. The spool has a pinion gear at each end of the spool and each pinion gear is engaged by a pair of racks with the racks in a pair moving at any given time in opposite directions. Each rack is constituted by spaced rack teeth formed in the side wall of a piston slidably mounted in a cylinder bore in the valve body, and the rotation of the valve spool is achieved by selective routing of pressurized fluid to the cylinder bores containing the pistons defining the racks.

Abstract: A hydraulic lock cylinder in which a cross bore is provided in an end structure of the cylinder housing which intersects the hydraulic fluid inlet passage to the central bore of the cylinder; a control piston is reciprocally mounted in the control bore; and pressurized fluid is admitted to the opposite ends of the control bore to shuttle the control piston within the control bore between a closed position in which the inlet passage is blocked and an open position in which the passage is open. The control piston includes a flat surface and a control port opening in the flat surface and an annular fitting screws into the inlet passage housing and includes a seal on its lower end for sealing coaction with the flat surface on the control piston to seal the inlet passsage.