A hot-runner injection molding apparatus that facilitates use of 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 actuator having a housing, wherein the valve pin is coupled to a drive shaft within the housing.

An injection molding apparatus, comprising: an injection molding machine; a distribution manifold having a distribution channel, a clamp device arranged to clamp together, under a selected clamp force, a mold system having a plurality of mold cavities one or more first downstream channels fluidly coupled to the distribution channel; one or more first gates arranged to deliver injection fluid to a first cavity; one or more second downstream channels fluidly coupled to the distribution channel; one or more second gates arranged to deliver injection fluid to a second cavity; a control system adapted to: instruct the first upstream valve and a second upstream valve; and at least one downstream valve having a valve pin having a control surface for controlling flow of injection fluid.

An improved actuator for a valve gate assembly is provided. The actuator includes a planetary assembly for converting rotation of an electrical motor into linear movement of a valve gate pin while also providing mechanical advantage to the motor against injection pressures from 15,000 psi to at least 25,000 psi. An internal cooling volume surrounds the motor for continuously cooling the motor with water, and an internal encoder converts an angular rotation within the actuator into an analog or digital signal for output to a controller.

Apparatus and method for detecting a position of an actuator piston driving a valve pin in an injection molding system. The apparatus includes an actuator housing having a body portion, surrounding an axial bore, of a substantially non-magnetic and/or magnetically permeable material, a piston, movable within the axial bore for driving a valve pin, the piston including a magnetic member generating a magnetic field such that axial movement of the piston in the bore modifies the magnetic field according to the position of the piston relative to a detection position, and a magnetic field detector attached to an exterior surface of the body portion at the detection position for detecting the magnetic field associated with the position of the piston and generating an output signal determined by the piston position.

An injection molding apparatus (5) comprising an injection molding machine (IMM), a heated manifold (60) that receives injection fluid (9) and distributes the injection fluid through a fluid distribution channel (120), a mold (70) having a cavity (80) and one or more valves (50) having a valve pin (100) the one or more valves (50) being comprised of: an electrically driven actuator (200), a controller including an algorithm that controllably limits rotation of a shaft (12) or output rotation device (16, 430, 500) during the course of an entire injection cycle to selectable angular positions that create a moment arm that extends between selected a selected minimum moment arm and a selected maximum moment arm, the selectable angular positions being between 70 degrees above and 70 degrees below an angular position that corresponds to the selected maximum moment arm.

An injection molding apparatus including: a valve pin driven by an actuator, the valve pin extending axially through at least a portion of the channel length of the fluid flow channel, the fluid flow channel including a throat, downstream flow of the injection fluid being restricted by a bulb portion of the pin, the valve pin having an intermediate position where downstream flow of injection fluid is unrestricted and a fully downstream position where downstream flow of injection fluid is stopped at both the gate and at the throat, wherein the actuator is driven by a valve assembly comprised of a spool mechanically driven by first and second actuators or solenoids that each separately engage the spool at opposing axial ends to effect movement of the spool back and forth between the drive fluid flow positions.

An apparatus and method for actuating a valve stem between an open position and a closed position and for taking one or more valve gated nozzle out of service is disclosed. The hot runner includes a valve gated nozzle having a valve stem, the valve stem coupled to a piston that is held against an actuation plate via pressurized air. When a valve stem becomes stuck in a gate of the hot runner, the actuation plate can continue to move while the piston remains stationary. The valve stem may also be protected from an over force situation such as if the valve stem encounters an obstruction as the actuation plate is moving toward the closed position.

An injection molding apparatus and method for adjusting the axial position of a valve pin in an injection molding system, the apparatus comprising: a top clamp plate, a heated manifold receiving and distributing an injection fluid to an exit of a fluid delivery channel to a cavity of the mold, an actuator comprising a housing having a chamber enclosing a drive member for driving a valve pin along an axial path of travel, the actuator housing slidably mounted and adapted for controlled upstream and downstream movement of the drive member along a path complementary to the axial path of travel of the valve pin, a mounting plate and an axial position adjustment screw screwably mounted within the mounting plate upstream of the housing of the actuator for controllably moving the valve pin to selectable starting or ending injection cycle axial positions.

A method of injection molding of plastic materials into a cavity of a mold with a molding apparatus including a distributor of the pressurized fluid plastic material connected to at least one injector having a pin valve displaceable between a fully closed position and an open position. The method includes a filling step following displacement of the pin valve from the fully closed position to the open position, a packing step of the pressurized plastic material keeping the pin valve in the open position, and a step of displacement and maintenance of the pin valve in at least one partially closed intermediate position prior to its complete closure.

The invention relates to a system for controlling a shutter (110) slidably arranged in a plastic material injection nozzle (11), comprising a rotary electric motor (M) and a mechanism adapted to couple said motor (M) to the shutter to slidably drive it between a closing position of the nozzle and a maximum opening position of the nozzle, characterised in that said mechanism comprises: an eccentric (21) integral with an output shaft (20) of the motor so as to be rotationally driven by said output shaft, comprising a crank pin (22) parallel to the output shaft but non-coaxial with said shaft (20), a slide (23) adapted to be made integral with one end of the shutter (110), and a connecting rod (25), a first end of which is articulated on the crank pin (22) of the eccentric (21) and a second end is articulated on an axis (25b) of the slide (23) such that the rotation of the eccentric causes sliding of the oscillating shutter between the closing position and the maximum opening position.