High-voltage circuit-breaker having a spring-loaded control mechanism with an energy-recovering additional spring

An electric circuit-breaker including an interrupting chamber with at least one moving contact inside the chamber, the moving contact being actuated by means of a spring-loaded mechanical control mechanism so as to open or close the circuit-breaker, the control mechanism including at least one first spring exerting a force tending to move the moving contact to open the circuit-breaker, and a second spring exerting a force tending to move the moving contact to close the circuit-breaker while loading the first spring, and in which circuit-breaker an additional spring is provided for exerting an additional force that is added to the force exerted by the first spring at the beginning of circuit-breaker opening, wherein the additional spring is mounted so that, before the end of circuit-breaker opening, the resultant of the force exerted by the additional spring for moving the moving contact is reversed so as to oppose the movement of the moving contact.