Medium voltage circuit breaker

1. A medium voltage circuit breaker comprising a pole assembly having, for each phase, a first fixed contact and a second movable contact reciprocally couplable/uncouplable between an open and close position, an actuator to actuate an opening and closing operation of said circuit breaker, and a kinematic chain operatively connecting said actuator to said movable contact, said kinematic chain comprising a sliding element operatively connected to said actuator and which is linearly movable by said actuator, said sliding element having a first sliding surface operatively coupled to said movable contact and a second sliding surface, which is opposite to said first sliding surface;

wherein said sliding element moves without rotating around the connection point with said actuator;

wherein said first sliding surface is coupled to a second roller that is connected to said movable contact and said second sliding surface is operatively coupled to a first roller that is mounted on a fixed part of the circuit breaker;

wherein said first sliding element is movable between an open position and closed position;

wherein a profile of said first sliding surface is not flat and is shaped so that the profile of said first sliding surface has at least a first and a second segment having different slopes;

wherein the profile of said second sliding surface is flat and straight for the entire length of said second sliding surface;

wherein said second roller and said movable contact are linearly movable along a same second direction of movement that is perpendicular to the first direction of movement of said sliding element;

wherein said first roller is in a fixed position with respect to said sliding element to support said sliding element.

2. The medium voltage circuit breaker according to claim 1 , wherein said sliding element is movable in a first direction and said second movable contact is movable in a second direction transverse to said first direction.

3. The medium voltage circuit breaker according to claim 1 , wherein that said sliding element is hinged on a first lever operatively connected to said actuator.

4. The medium voltage circuit breaker according claim 1 , wherein said sliding element comprises the second sliding surface operatively coupled to the first roller.

5. The medium voltage circuit breaker according to claim 1 , wherein said first sliding surface is operatively coupled to the second roller connected to said movable contact.

6. The medium voltage circuit breaker according to claim 1 , wherein the profile of said first sliding surface is shaped so as to provide a variable speed of said movable contact during said opening and closing operation of said circuit breaker.

7. The medium voltage circuit breaker according to claim 1 , wherein said sliding element is made of insulating material.

8. The medium voltage circuit breaker according to claim 1 , further comprising a control device that checks the position of the contacts and drives a corresponding interlock device, said control device being operatively positioned on said sliding element.

9. The medium voltage circuit breaker according to claim 2 , wherein that said sliding element is hinged on a first lever operatively connected to said actuator.

10. The medium voltage circuit breaker according to claim 2 , wherein said sliding element comprises a second sliding surface operatively coupled to the first roller.

11. The medium voltage circuit breaker according to claim 3 , wherein said sliding element comprises the second sliding surface operatively coupled to the first roller.

12. The medium voltage circuit breaker according to claim 2 , wherein said first sliding surface is operatively coupled to the second roller connected to said movable contact.

13. The medium voltage circuit breaker according to claim 3 , wherein said first sliding surface is operatively coupled to the second roller connected to said movable contact.