US Patent 11148335 Injection molding flow control apparatus and method

An apparatus for controlling the rate of flow of a fluid mold material comprising:a manifold,an actuator interconnected to a valve pin,a position sensor that senses position of the valve pin,a controller that controls movement of the actuator according to instructions that instruct the actuator to drive the valve pin upstream at one or more selected intermediate velocities in response to receipt by the controller of a signal from the position sensor that the valve pin is disposed in the one or more intermediate upstream gate open positions.