Abstract: A drive apparatus for a tensioning shaft of a spring energy drive of an electric switch has a kinematic chain for connecting a drive element to the shaft and a control element. Within the chain, a first link which can be coupled to the shaft in rotationally fixed fashion and a second link arranged coaxially regarding the first link and capable of rotating under the force of the drive element are coupled to one another in a form-fitting and/or force-fitting manner by a coupling element which is moved by the control element on one of the two links such that the link coupling is released when a predetermined first angular link position is reached and is produced again when a predetermined second angular link position is overshot. To provide the drive apparatus with a more compact configuration, the coupling element can be moved in the radial direction of the shaft.

Abstract: A drive apparatus for a tensioning shaft of a spring energy drive of an electric switch has a kinematic chain for connecting a drive element to the shaft and a control element. Within the chain, a first link which can be coupled to the shaft in rotationally fixed fashion and a second link arranged coaxially regarding the first link and capable of rotating under the force of the drive element are coupled to one another in a form-fitting and/or force-fitting manner by a coupling element which is moved by the control element on one of the two links such that the link coupling is released when a predetermined first angular link position is reached and is produced again when a predetermined second angular link position is overshot. To provide the drive apparatus with a more compact configuration, the coupling element can be moved in the radial direction of the shaft.

Abstract: A closure device for a withdrawable rack adapted for receiving power circuit breaker includes a plate arrangement having at least two plates provided with openings and movable relative to one another so that the plate arrangement is changeable between an open position in which the openings of the plates are in alignment and a closed position in which the openings are out of alignment. An actuating mechanism is acted upon by the power circuit breaker as it is inserted to cause a movement of at least one of the plates to thereby change the plate arrangement between the closed and open positions. The actuating mechanism includes two V-shaped linkage assemblies. Each linkage assembly has two legs connected by a hinge to allow the linkage assembly to spread apart, with one of the legs having a free end which is connected to the at least one of the plates, and a coupler is connected to the hinge. Both couplers are jointly articulated to actuating element.