Patent attributes
A drive mechanism for imparting movements to a door which pivots about a generally vertical axis between open and closed positions. The drive mechanism includes a frame, a power source mounted on the frame or positively driving an output shaft of the drive mechanism and thus, moving the door from a closed position toward an open position. The drive mechanism also includes an output shaft mounted for rotation about a fixed axis disposed generally parallel to a fixed axis of a power source drive shaft. A drive train including a plurality of intermeshing gear sets is arranged between the power source drive shaft and the output shaft. At least one gear set in the drive train includes a clutch mechanism selectively operable in either an engaged condition or a disengaged condition. When in a disengaged condition, the clutch mechanism operably transfers rotational movements of the power source to the output shaft so as to forcibly open the door. When operated in an engaged condition, the clutch mechanism operationally disconnect the power source and at least one gear set from the drive train thereby minimizing the manual effort required to open the door.
