Abstract: A door operator for a reversibly operable door, such as a garage door includes a frame, a motor on the frame, a flexible drive member connected to the motor, and a carriage is mounted for movement along the frame. The carriage moves generally parallel to a portion of the frame and is attached to the door to open and close the door by movement of the carriage along the frame. The carriage can be selectively engaged and disengaged from the flexible drive member using an actuating member extending from the carriage. The carriage and the flexible drive member are engaged and disengaged upon successive motions of the actuating member in a direction substantially perpendicular to the direction of travel of the carriage.

Abstract: A door operator for a reversibly operable door, such as a garage door, includes a frame and a carriage movably mounted on the frame and attached to a door for moving the door between open and closed positions. A flexible drive member, such as an endless chain, extends on the frame and is capable of moving the carriage. A drive train is on the frame connected for moving the flexible drive member. A motor housing is mounted on the frame within the motor housing and connected to the drive train. The motor has a shaft extending from the motor housing and engaging the drive train. A bearing assembly that includes metal thrust bearings is on the shaft adjacent to the motor. The metal thrust bearing assembly increases the performance of the electric motor, and thus provides a more powerful motor without changing to a larger motor or otherwise modifying the motor design. The motor is mounted on the frame so as to allow the shaft freely to move axially relative to the motor to permit the shaft to self-align.