Abstract: A bolt of the type mounted in a door is longitudinally movable between extended and retracted positions by a reversible electric motor connected to the bolt through gear means and a part of manual operator means for the bolt. The gear means from the motor includes extensive gear reduction and terminates in a driving gear comprised of circumferentially spaced gear segments engageable with a driven gear telescoped with the manual operator means, the driving gear segments being positioned completely disengaging the driven gear at either of the bolt extended or retracted positions and either gear segment engaging the driven gear for moving the bolt between its extended and retracted positions. Thus, the bolt may be moved between its extended and retracted positions either by the manual operator means without consequent movement of the major portion of the gear means and electric motor, or by the electric motor and gear means.