Patent ID: 6819205
Filing Date: 2004-11-16
Classification: H01H

Abstract:
A circuit breaker including current-limiting opening of a moving switching contact, comprising:a drive apparatus for moving the switching contact to a connected position and to a disconnected position; and a latching device, arranged in the path of a force transmission from the drive apparatus to the switching contact, wherein the latching device, starting with the switching contact in the connected position, is adapted to be released by use of an opening force originating from the switching contact and acting in the direction of the disconnected position, when the opening force exceeds a predetermined limit value, wherein the latching device is in the form of a mechanical connecting element between the drive apparatus and the moving switching contact, including at least two interacting working surfaces arranged at an angle to the direction of the opening force, and including a contact-pressure spring adapted to act on the working surfaces, wherein the latching device includes two levers, connected to one another by a hinged joint formed by a hinge bolt, passed through aligned through-holes in concentric parts of the levers, wherein the levers are designed to be identical and designed to pivot relative to one another about the hinged joint, wherein the levers include inclined surfaces, adapted to act as a toothed system, on the concentric parts on their touching surfaces in the area of the hinged joint, wherein the levers are arranged concentrically around the through-holes for the hinge bolt and wherein a spring force generated by a contact-pressure spring, which acts on the toothed system that is formed by the inclined surfaces on their touching surfaces, is adapted to act on the concentric parts of the levers, wherein, when the latching device is in the rest state, the levers are at an angle to one another, which is not the same as the angle when they are in the extended position, in order to produce a relative torque which is dependent on the opening force, and wherein those ends of the levers facing away from the hinged joint include holders, provided with through-holes for hinged connection to the switching contact and, respectively, to the drive apparatus.