Abstract: A releasable drive assembly is described, suitable for use with a rolling door. The illustrated assembly comprises a chassis, a final drive unit rotatably mounted to the chassis for operating the door, a motor fixed with respect to the chassis, drive means interconnecting the motor with the final drive unit, the drive means including a clutch for releasing and re-engaging the motor and the final drive unit, the clutch including a slidable clutch unit keyed for rotation with one part of the drive means and having axially projecting formations respectively engageable and disengageable with mating formations on the other part of the drive means upon sliding movement of the clutch unit, latchable disengagement means for selective engagement with the slidable clutch unit for sliding the clutch unit into and out of engagement with the mating formations, the disengagement means being latchable to hold the clutch unit in its disengaged position.

Abstract: A rolling door drive assembly including a chassis, a final drive unit rotatably mounted to the chassis for operating the door, a motor fixed with respect to the chassis, a drive device interconnecting the motor and the final drive unit, a housing defining a mounting channel on the assembly remote from the final drive unit, the mounting channel extending transversely to the axis of rotation of the final drive unit and adapted to receive part of a mounting bracket, and a mounting member extending into the mounting channel in a direction parallel to the axis for engagement with the mounting bracket.

Abstract: A roller shutter or door drum driving mechanism of the kind comprising a pivotally mounted electric motor, a gear train fixedly associated with said motor terminating in a pinion, a ring gear on the drum and manually operable, is furnished with releasable latch means which secure said motor and train in an operative position wherein the pinion meshes with the ring gear but, when released, permit the motor to move to an in-operative position wherein the pinion is clear of the ring gear.