| 摘要 |
A low-voltage circuit breaker, comprising: a rotating contact supporting shaft, is provided with a seat that accomodates the central body of a moving contact so that the first arm protrudes externally from the seat, at least one first spring and one second spring being furthermore arranged in the contact supporting shaft and being suitable to ensure, when the circuit breaker is closed, an adequate contact pressure between the active surface and the fixed contact; the particularity of the circuit breaker consisting of the fact that a first pivot is fixed to the contact supporting shaft and is coupled to a hole formed in the central body, engagement means and at least one second pivot being furthermore arranged on the shaft on mutually opposite sides with respect to the first pivot, the second pivot being movable with respect to the shaft and to the moving contact, the first and second springs being furthermore anchored to the second pivot and to the engagement means and being arranged along two opposite sides of the arm of the moving contact, the second pivot interacting functionally with the first cam-like surface so as to generate a mechanical moment that matches the direction of rotation of the moving contact during at least one portion of the step for separation of the active surface from the fixed contact in a short-circuit condition.
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