Position adjusting system for a seat of a vehicle

A position adjusting system for adjusting the position of a seat n a vehicle and preventing movement of the seat resulting from external forces acting on the seat. The system includes a seat track fixable to the vehicle, a motor actuator, and a gear train engaged with the motor actuator. The seat track is adapted to cooperate with the seat track to convert movement of the motor actuator into movement of the seat track and the seat. A non-reversing clutch mechanism is coupled with the gear train and adapted to transfer torque from the motor actuator through the gear train to move the seat upon actuation of the motor actuator but locking upon torque being applied through the seat track, thereby preventing the external forces acting on the seat from moving the seat relative to the vehicle.