Abstract: A driving apparatus for an object which can be moved to and fro such as a te wing, comprising a guide block movable along a guide rail (1), said guide block being coupled to the object and to a driving member (2,2') movable by a motor and, with the aim of easy assemblage from only a small number of easily manufacturable components, consisting of a guide block component (3), having slidably supported thereon an actuating member (7), and of a manually actuated coupling member (5) spring-loaded towards the coupled position with the driving member, the actuating member (7) being in operative connection with the coupling member (5) through a bolt (8) stationary with said one member (7) and engaging at a sliding edge construction (9) formed in said other member (5) so that, when the actuating member (7) is displaced, the coupling member is brought against the direction of force of the spring acting thereon from the coupled position in the uncoupled position and automatically held in an end portion of the sliding ed

Abstract: A safety arrangement for a motor-driven door or gate used to close building ntrances or doorways, in which a vertically movable overhead door consists of one part or a multiple number of parts. An elastically deformable hollow rubber section is provided at the closing edge of the door, and this hollow rubber section has an interior hollow space with first and second ends. At the first end of this hollow space, there is an air pressure-wave receiver signal transformer, whereas an air pressure-wave transmitter is connected to the second end. This transmitter generates a continuous air pressure oscillation having a first pulse duration and a first pulse frequency when the closing edge is freely movable through a path of motion of the door. The continuous oscillation has a second pulse duration which differs from the first pulse duration, and a second pulse frequency differing from the first pulse frequency when the closing edge strikes against an object positioned in the path of motion of the door.