US Patent 7210922 Valve pin operating mechanism

A hot runner injection molding apparatus includes a manifold for transferring molten plastic into a channel to a mold gate. A valve pin extends at least partially through the channel and is reciprocally movable from a retracted position to an extended position to close the mold gate when the valve pin is in the extended position, and to open the mold gate when the valve pin is in the retracted position. A valve pin moving mechanism is coupled with the valve pin to directly move the valve pin to the extended position; and a resilient coupling is located between the valve pin and the valve pin moving mechanism for normally moving the valve pin to the retracted position.