Patent ID: 7205735
Filing Date: 2007-04-17
Classification: E05F,E05Y

Abstract:
1. A barrier movement operator comprising: an A.C. motor having a rotatable rotor connected to a barrier for movement thereof; sensing apparatus to generate motor signals representing an operational variable of the motor; controller for controlling movement of the barrier by controlling the energization of the motor and being responsive to changes in the sensed operational variable represented by the motor signals for changing the energization of the motor wherein; the motor is constructed to exhibit an enhanced operating characteristic of sensed operational variable to torque to improve the rapid detection by the controller of changes in a rate of movement of the barrier by detecting changes in the operational variable; wherein the sensed operational variable is the rate of rotation of the rotor of the motor; and wherein the motor exhibits a no load rotation rate in the range of 1000 to 2000 revolutions per minute and an operating characteristic in which a change in torque output of the motor of approximately 1 ft.lb. results in a change in the rotation rate of the range of 30 to 120 revolutions per minute.