Garage door operator

A door operator for actuating an overhead garage door which is counterbalanced by means including a drum shaft having a drum thereon for a lift cable attached to the door, comprising a frame having a main shaft journalled therein, and a worm gear mounted on said shaft and drivingly connected thereto, a motor mounted on said frame and a worm mounted on the shaft of such motor in driving relation with the worm gear on the main shaft, means for coupling the main shaft in coaxial driving relation with the drum shaft of the door counterbalance means, a mounting plate adapted to be mounted on a fixed support, means for adjustably mounting said frame on said plate so as to position the main shaft in axial alignment with the drum shaft, said mounting means comprising mounting studs on said mounting plate, said frame having flanges thereon through which said studs project, and means for securing the flanges in adjusted positions axially of the studs.

A door operator for actuating an overhead garage door which is counterbalanced by means including a drum shaft having a drum thereon for a lift cable attached to the door, comprising

• a frame having a main shaft journalled therein, a worm gear mounted on said shaft and drivingly connected thereto, a motor mounted on said frame, and a worm mounted on the shaft of such motor in driving relation with the worm gear on the main shaft, mounting means for mounting the main shaft coaxially to the drum shaft so as to drivingly interconnect such shafts and provide substantial support from the drum shaft for the main shaft and the operator assembly while permitting rotation of such assembly about the drum shaft axis,
• means forming a torque-reaction train to oppose such rotation, a yieldable element in the torque reaction train, and a reversing switch actuated in response to excess torque reaction through such train.

A door operator unit adapted to be mounted directly on the end of the counterbalance shaft of an overhead garage door which is counterbalanced by means including such a shaft and a lift cable attached to the door, comprising

• a compact unitary assembly including a frame having a main shaft journalled therein, a worm gear mounted on said shaft and drivingly connected thereto, a motor mounted on said frame, and a worm mounted on the shaft of such motor in driving relation with the worm gear on the main shaft,
• means for connecting the main shaft in coaxial end-to-end relation with the counterbalance shaft so as to support the unitary assembly by its said main shaft directly on the counterbalance shaft and thereby provide at least the primary support for such assembly,
• and stabilizing means including means for transmitting torque reaction from said unitary assembly to a fixed support.

A door operator for actuating an overhead garage door which is counterbalanced by means including a drum shaft having a drum thereon for a lift cable attached to the door, comprising

• a unitary assembly including a frame having a main shaft journalled therein, and a worm gear mounted on said shaft and drivingly connected thereto, a motor mounted on said frame, and a worm mounted on the shaft of such motor in driving relation with the worm gear on the main shaft,
• means for mounting said assembly with the main shaft in coaxial driving relation with the drum shaft of the door counterbalance means,
• and motor control means comprising a threaded extension on said main shaft, one or more travelling nuts mounted on said extension, a mounting plate extending axially of said shaft extension, switch means mounted on said plate and having actuating means in the path of the nut or nuts, and a stop bar removably mounted on said mounting plate and slidably engaged with radial faces on said nut or nuts so as to prevent their rotation and cause them to travel axially in response to rotation of said shaft extension for actuation of said switch means.