Abstract: An actuating mechanism for a circuit breaker includes a first piston movable in a first cylinder, against the force of a first compressible member, by admitting hydraulic fluid, and a second piston movable in a second cylinder, against the force of a second compressible member, by admitting hydraulic fluid. Hydraulic fluid can transferred from the second cylinder into the first cylinder via an interconnecting fluid passage, and released from the first cylinder via an outlet fluid passage. The first piston is arranged to be connected to a circuit breaker in a switchgear so as to open and close it. Importantly, the first piston is directly mechanically connected to the first compressible member, ensuring that all the energy stored in the compressible member is available to open the circuit breaker.

Abstract: A control device (10) for an electrical switchgear with three switching positions including a closed position, an open position and an earthing position. The switchgear includes a main shaft (14) and a drive shaft (28). The control device includes a mode selector lever (30) designed to select one operating mode among a motor driven switching mode, a manual switching mode between the open position and the closed position of the electrical switchgear, and a manual switching mode between the open position and the earthing position of the electrical switchgear. The mode selector lever has an opening with a curved contour, and the control device includes a cam disk (50) with a cam (54) capable of moving inside the opening (40). The control device may be applied to an isolating switch.

Abstract: A control device (10) for an electrical switchgear with three switching positions, of the type comprising a closed position, an open position and an earthing position, comprising a main shaft (14) and a drive shaft (28), comprises: a mode selector lever (30) designed to select one operating mode among the <<motor driven switching mode>>, the <<manual switching mode between the open position and the closed position of the electrical switchgear>> and the <<manual switching mode between the open position and the earthing position of the electrical switchgear>>, that comprises an opening with a curved contour, and a cam disk (50) with a cam (54) capable of moving inside said opening (40). Application to an isolating switch.