Abstract: An operating mechanism of a three-position switch comprises a tumbler device with an energy storage spring associated with a toggle, a main operating crank controlled by a switching shaft, and an earthing crank mounted in rotation on a first operating spindle. Opening and closing are performed by means of a second operating spindle, offset from the operating shaft and operating in conjunction with a transmission system designed to drive the toggle. A latching lever of the main crank is unlocked by a boss when the toggle is in the vicinity of the dead-point.

Abstract: A latching mechanism comprises an energy storage system having a first closing spring, and a second opening and earthing spring, arranged between a transmission device and a closing control crankshaft and an earthing crank. A retaining plate pivoting on an axis cooperates on the one hand with an opening control lock by means of a unidirectional locking and on the other hand with the crankshaft by means of two latchings. The first latching is released during the opening travel after the lock has been unlocked, and the second latching causes positive locking of the device at the beginning of the closing travel of the crankshaft.