Abstract: A spring drive mechanism for switchgear, in particular for a circuit breaker. The mechanism has an engagement shaft that is rotatable about its axis, a large toothed-wheel mounted on said shaft, a small toothed-wheel meshing with said large toothed-wheel to put an engagement spring under stress, and a mechanism which prevents the large toothed-wheel and the small toothed-wheel jamming each other mutually after the shaft has been released. The mechanism which prevents jamming includes the shape of the teeth of said small toothed-wheel and the shape of the teeth of the large toothed-wheel. In the teeth of the large toothed-wheel there is a first gap followed, in the direction of rotation, by a first retractable tooth that is retractable along the axis of the tooth against bias from a spring. This tooth is followed by a second gap extending over a length that is not less than two gear pitch steps and is slightly less than an integer number of steps.

Abstract: A spring drive mechanism for power switch gear. The mechanism includes an engagement shaft free to rotate about its own axis and carrying both a large toothed wheel and a cam. An engagement spring constituted by a traction spring is coupled to the large toothed wheel at an attachment point by a chain. The large toothed wheel meshes with a small toothed wheel which is coupled via a gear train to a driving gearwheel secured to an outlet shaft of a drive motor. In the predetermined direction A of rotation, the large toothed wheel includes a discontinuity in its teeth, thereby generating a gap which constitutes a zone without teeth, and in which a retractable tooth is disposed. Following the retractable tooth, the large toothed wheel has an additional discontinuity in its teeth over at least two meshing steps. This mechanism is advantageous as switchgear for a circuit breaker.

Abstract: A spring drive for an electrical switching apparatus has a switch-on shaft to which a switch-on spring is coupled eccentrically and on which a large wheel (16) is seated in a rotationally fixed manner. A small wheel (20), which is driven in order to stress the switch-on spring, interacts with the large wheel (16). A tooth system (52) on the large wheel (16) has a gap (54) for decoupling the wheel pair (18) formed by large wheel (16) and small wheel (20) when the switch-on spring is stressed. In order to connect the switching apparatus, the large wheel (16) is driven in a rotation direction (D), as a result of which the tooth system (52) engages with the small wheel (20) again. In order to prevent blocking when the teeth engage in one another, the teeth (60) on the small wheel (20) are constructed in such a manner that the edges (56, 58) abut against one another radially on an outer side at a common edge (62).

Abstract: A drive device includes a cam disk (18), which, for switching on the power switch, can be driven by means of an energy store, impulsively, in a direction of rotation (D). A first section (48) of the curve path (20) of the cam disk (18), which, as the azimuth increases counter to the direction of rotation (D), exhibits an increasing radius, is adjoined by an intermediate section (50) of steadily decreasing radius. After this intermediate section (50) there follows a second section (52), running roughly in the radial direction. As a result of the interaction of the first section (48) with the roller (22'), the triangular lever (76), together with the control shaft (26), moves counter to the direction of rotation (D) out of the switch-off setting into the switch-on setting and by a measure of one overtravel (U) beyond this.