Automatic reversing control equipment

Abstract

Abstract Control equipment for a reversible electric motor for driving a mechanism such as a garage door operator is disclosed. The control equipment includes a pressure responsive device for moving a movable switch element between first and second motor energizing positions in a circuit. The movable switch element in one of the circuit positions conditions the motor for operation in one direction, and in the other of the circuit positions conditions the motor for operation in another direction. The equipment further includes a relay normally selectively energizable by an operator controlled switch to alternately complete first or second motor energizing circuit paths, depending upon the position of the switch elements, to permit movement of the mechanism in the direction desired. In order to reverse the door when it encounters an obstruction in closing, a circuit is provided to the relay which bypasses the operator controlled switch. The pressure responsive device first operates a bypass switch in the bypass circuit and then moves the aforesaid movable switch element to the one of its positions which conditions the motor for operation in a direction reverse to the direction in which the motor was operating at the time the obstruction was encountered. Simultaneously, the movable switch element closes contacts which complete the bypass circuit, thereby energizing the relay to complete the motor circuit causing the motor to operate in the reverse direction. Means are provided for disabling the bypass switch, thereby preventing energization of the relay via the bypass circuit at the close limit of door travel. First and second thermal cutouts are provided for preventing unduly repetitious operation of the motor and to provide motor protection.

Inventors

• 👤 John W Ellmore

Bibliographic Details