An apparatus for controlling the rate of flow of fluid mold material from an injection molding machine to a mold cavity, the apparatus comprising: a manifold having a delivery channel that delivers fluid material to a first gate; an actuator interconnected to a valve pin having a tip end drivable along a drive path, the actuator and the valve pin being translationally driven at a controllable rate of travel by a valve system comprised of a source of valve drive fluid that pumps the drive fluid at a maximum drive rate, a first valve interconnected to the source that is selectively adjustable to adjust rate of flow of the drive fluid from the source to a selected less than maximum drive rate and a second valve controllably movable between a first position and a second position.

An injection molding apparatus comprising a heated manifold, an actuator comprised of an actuator housing containing a drive member interconnected to a valve pin having a drive axis, one or more heat convectors each heat convector comprised of a heat conductive leg disposed within a gap disposed between the manifold and a downstream end of the actuator housing and a heat conductive arm extending distally upstream and away from the gap such that heat is conducted from the leg to the arm upstream and away from the downstream end of the actuator housing.

A method is described for operating an actuator adapted to move via a pressurized fluid circuit a valve pin of an injection nozzle for molten material within a mold, wherein the valve pin moves from a closing position, where no molten material passes through the nozzle, to an opening position, where molten material passes through the nozzle, and the actuator comprises a chamber and a piston that is movably mounted in the chamber, linearly displaced by the thrust of the fluid and connected to the valve pin to move it. The valve pin is moved by injecting or extracting a predetermined amount of fluid into/from the chamber.

An injection molding apparatus comprising a clamp plate, a heated manifold, an actuator, a mold and a cooling device, wherein the cooling device comprises: a heat transmitter comprising a distal arm or member and a proximal base or member, the distal arm or member or member being mounted by a spring loadable interconnection or engagement to or with the proximal base or member, the clamp plate, the mold, the manifold, the actuator and the heat transmitter being assemblable together in an arrangement wherein the spring loadable interconnection is loaded urging the distal end surface of the distal arm or member into compressed engagement with the clamp plate.

An injection molding apparatus comprising a clamp plate, a heated manifold, an actuator, a mold and a cooling device, wherein the cooling device comprises: a heat transmitter comprising a distal arm or member and a proximal base or member, the distal arm or member or member being mounted by a spring loadable interconnection or engagement to or with the proximal base or member, the clamp plate, the mold, the manifold, the actuator and the heat transmitter being assemblable together in an arrangement wherein the spring loadable interconnection is loaded urging the distal end surface of the distal arm or member into compressed engagement with the clamp plate.

An injection molding apparatus comprising a clamp plate, a heated manifold, an actuator, a mold and a cooling device, wherein the cooling device comprises: a heat transmitter comprising a distal arm or member and a proximal base or member, the distal arm or member or member being mounted by a spring loadable interconnection or engagement to or with the proximal base or member, the clamp plate, the mold, the manifold, the actuator and the heat transmitter being assemblable together in an arrangement wherein the spring loadable interconnection is loaded urging the distal end surface of the distal arm or member into compressed engagement with the clamp plate.

An injection molding apparatus comprising a clamp plate, a heated manifold, an actuator, a mold and a cooling device, wherein the cooling device comprises: a heat transmitter comprising a distal arm or member and a proximal base or member, the distal arm or member or member being mounted by a spring loadable interconnection or engagement to or with the proximal base or member, the clamp plate, the mold, the manifold, the actuator and the heat transmitter being assemblable together in an arrangement wherein the spring loadable interconnection is loaded urging the distal end surface of the distal arm or member into compressed engagement with the clamp plate.

A hot-runner injection molding apparatus that facilitates use of electric actuators in a compact design includes a hot-runner manifold defining resin channels for conveying resin to nozzles that serve as conduits for introducing liquid resin into a mold cavity, a valve pin configured for linear movement along a longitudinal axis of the nozzle to control flow of liquid resin through the nozzle, and an electric actuator having a body containing an electric motor, wherein the electric actuator body includes channels for circulating a coolant.