Patent ID: 9691559
Date: 2017-06-27
CPC Classifications: H01H

Claim:
1. A circuit breaker including a moving contact assembly that is brought into contact with or separated from fixed contact points, the moving contact assembly comprising: a shaft that is rotatable in a first direction or a second direction opposite to the first direction by means of a switching mechanism; a moving contact that is held to be rotatable in the first or second direction with respect to the shaft, with a rotation axis not fixed to the shaft; and springs that apply torque to the moving contact in the first direction, the shaft comprising: stopping faces that are formed in a direction opposite to the first direction in which the moving contact rotates; and guiding faces that are curved from the stopping faces and face the rotation axis of the shaft, wherein the stopping faces are formed on a radius of rotation of the shaft, and the guiding faces are shaped like an arc bulging toward the rotation axis of the shaft when viewed from a cross-section perpendicular to the rotation axis of the shaft, the moving contact comprising: first surfaces that are formed on the radius of rotation of the moving contact and brought into contact with the stopping face; and sliding surfaces that are located at an angle to the first surfaces, face the rotation axis of the moving contact, and are slanted toward a center of rotation with respect toa line of action of a tangential force of torque at a points of contact with the guiding faces, wherein a position of the moving contact is corrected depending on positional errors of the points of contact when the moving contact comes into contact with the fixed contact points, and when the moving contact is separated from the fixed contact points, a component force of the torque directed toward the sliding surfaces causes the sliding surfaces to move with respect to the guiding faces against the frictional force and returns the moving contact to a normal position where the rotation axis of the moving contact coincides with the rotation axis of the shaft.