Device for controlling an electric power cutoff device

A device for controlling a circuit-breaker intended for opening and closing this electric power cut-off device comprising a mobile contact, this control device comprising a motor (3) with a rotary output shaft (12) and being connected to power supply means (4-9) and to actuation means transforming the output displacement of said motor (3) into a displacement of said contact, the device also comprising an arrangement of a mechanical spring involved in opening and closing said contact, said spring arrangement including two pre-stressed and antagonist mechanical springs, a first spring (15), a so-called opening spring, ensuring the opening of said contact and a second spring (16), a so-called closing spring, ensuring the closing of said contact, said actuation means being stressed by each of these two springs separated by a ring (18), and including an arrangement for immobilizing said contact in the open position and the closed position,

• characterized in that said actuation means include a set of jointed elements providing the connection of said rotary shaft (12) and of said ring (18), and in that, in the closed position of said contact, said set of jointed elements abuts against an abutment element (19) near a dead centre position, a so-called open dead centre, the opening spring (15) only being able to drive it towards the open position upon moving past this dead centre during opening.