Fast acting reduced velocity pin control

Apparatus for performing an injection cycle comprising:

• a manifold that receives an injection fluid material, the manifold having or communicating with a delivery channel that delivers the injection fluid mold material under an injection pressure to a gate of a mold cavity,
• a pneumatic actuator driven by a source of pressurized gas having a selected maximum pressure capable of driving the actuator and an interconnected valve pin at one or more maximum velocities, the pneumatic actuator comprising a pair of opposing first and second gas drive chambers,
• the actuator driving the valve pin upstream and downstream during a single injection cycle along a path of travel having a selected stroke length that extends between a first position where the valve pin prevents the injection fluid material from flowing into the cavity and one or more selected maximum flow positions at which the injection fluid material flows at a maximum rate through the gate into the cavity,
• the valve pin and the fluid delivery channel being adapted to vary rate of flow of the injection fluid material to less than the maximum rate when the valve pin is disposed at one or more selectable intermediate positions between the first position and the maximum flow position,
• the pneumatic actuator being controllably drivable to drive the pin upstream or downstream at one or more selectable reduced velocities that are less than the one or more maximum velocities,
• a pneumatic valve assembly that controls the rate of delivery of the pressurized gas from the source to and from the gas drive chambers of the pneumatic actuator to controllably drive the actuator and valve pin upstream and downstream, the pneumatic valve assembly comprising a cylinder housing having fluid delivery ports for delivering pressurized gas to and from the gas drive chambers of the actuator and a spool controllably and translationally drivable within the cylinder housing to selectively open and close the fluid delivery ports a selected degree to control flow of pressurized gas to and from the drive chambers,
• the pneumatic valve assembly including a drive member mounted to the spool, the drive member being controllably energizable to cause the spool to controllably slide along a back and forth path of lateral travel, the drive member being translationally movable along the back and forth path of lateral travel together with the spool and being supported during movement solely by mounting to the spool,
• the apparatus including a controller that receives position or pressure signal feedback and contains instructions that instruct the pneumatic valve assembly to cause the actuator to drive the valve pin through the one or more selectable intermediate positions over a selectable time or distance based on receipt of the real-time signal feedback.