SPEED GOVERNING AND DECOUPLING DRIVE MECHANISM

摘要

A decoupling and speed governing mechanism is disclosed for a spring returned drive train driven by a stepper motor. A pinion assembly in the drive train is rotatably coupled to a rotor in the motor by dogs on the assembly which engage spokes in the rotor when the assembly is in a first position along the axis of the rotor. The pinion assembly also includes weighted shoes which move outwardly when the assembly rotates at greater than a predetermined speed to frictionally engage an internal drum surface in the rotor to govern the drive train speed when the assembly is in a second axial position relative to the rotor.