Non-coaxially mounted electric actuator and transmission

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 that receives an injection fluid mold material, the manifold having a delivery channel that delivers the injection fluid mold material under an injection pressure to a gate of a mold cavity disposed within a mold, the gate being controllably opened and closed by a valve pin having a pin axis, the valve pin being slidably mounted for reciprocal upstream and downstream linear movement along the pin axis such that a downstream end of the valve pin is drivable into and out of open and closed positions relative to the gate,
• an electric actuator comprising an electric motor comprised of a motor housing that houses a drive shaft having a drive gear and a drive axis that is rotatably mounted within the motor housing and is drivably rotatable around the drive axis by a source of electrical power or energy and a transmission comprised of a transmission gear rotatably mounted within a transmission housing, the transmission gear having a gear axis and being drivably rotatable around the gear axis,
• the drive gear, the transmission gear and the valve pin being drivably interconnected and arranged such that the drive axis and the gear axis are non-coaxially mounted or disposed relative to each other and such that driven rotation of the drive gear around the drive axis rotatably drives the transmission gear around the gear axis and linearly drives the valve pin along the pin axis,
• a controller that controllably operates the motor to control the velocity or rate of travel of upstream withdrawal or downstream closure of the valve pin with respect to the gate at selected times or over selected lengths of time over the course of an injection cycle, and
• wherein the actuator, interconnected to the valve pin, drives a tip end of the valve pin along the pin axis on a drive path that extends between a first position where the tip end of the valve pin obstructs the gate to prevent the injection fluid material from flowing into the cavity, a second position upstream of the first position wherein the tip end of the valve pin restricts flow of the injection fluid through the gate along at least a portion of the length of the drive path extending between the first position and the second position, and a third position upstream of the second position where the injection fluid material flows freely through the gate without restriction from the tip end of the valve pin.

A method of driving a valve pin in 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 that receives an injection fluid mold material, the manifold having a delivery channel that delivers the injection fluid mold material under an injection pressure to a gate of a mold cavity disposed within a mold, the gate being controllably opened and closed by a valve pin having a pin axis, a pin stem and a pin connector, the valve pin being slidably mounted for reciprocal upstream and downstream linear movement along the pin axis such that a downstream end of the valve pin is drivable into and out of open and closed positions relative to the gate,
• an electric actuator comprising an electric motor comprised of a motor housing that houses a drive shaft having a drive gear and a drive axis that is rotatably mounted within the motor housing and is drivably rotatable around the drive axis by a source of electrical power or energy and a transmission comprised of a transmission gear rotatably mounted within a transmission housing, the transmission gear having a gear axis and being drivably rotatable around the gear axis,
• the drive gear and the transmission gear being drivably interconnected and arranged such that the drive axis and the gear axis are non-coaxially mounted or disposed relative to each other and such that driven rotation of the drive gear around the drive axis rotatably drives the transmission gear around the gear axis,
• a controller that controllably operates the motor to control the velocity or rate of travel of upstream withdrawal or downstream closure of the valve pin at selected times or over selected lengths of time over the course of an injection cycle,
• the method comprising:
• the controller controllably operating the motor to drive the valve pin at one or more velocities or rates of travel of upstream withdrawal or downstream closure of the valve pin at selected times or over selected lengths of time over the course of an injection cycle,
• wherein the actuator, interconnected to the valve pin, drives a tip end of the valve pin along the pin axis on a drive path that extends between a first position where the tip end of the valve pin obstructs the gate to prevent the injection fluid material from flowing into the cavity, a second position upstream of the first position wherein the tip end of the valve pin restricts flow of the injection fluid through the gate along at least a portion of the length of the drive path extending between the first position and the second position, and a third position upstream of the second position where the injection fluid material flows freely through the gate without restriction from the tip end of the valve pin.