Circuit breaker with rebound preventer

1. A circuit breaker comprising:

a main body;

a fixed contact fixed to the main body;

a movable contact contactable with or separated from the fixed contact, the movable contact being movably installed at the main body;

a main shaft connected to one side of the movable contact, the main shaft being rotatably installed on the main body;

a trip mechanism coupled to another side of the main shaft and configured to rotate the main shaft; and

a rebound preventer having one end rotatably installed on the main body and provided with a stopping unit formed at another end thereof and engaged with the main shaft,

wherein the stopping unit is provided with a stopping groove including first and second contact surfaces facing each other,

wherein the first contact surface comes in contact with a part of the main shaft when separating the movable contact so as to rotate the rebound preventer in a direction opposite to the main shaft being rotated,

wherein the second contact surface restricts a reverse rotation of the main shaft when the second contact comes in contact with the part of the main shaft in a state where the rebound preventer has been rotated over a prescribed range.

2. The circuit breaker of claim 1 , wherein an end of the first contact surface extends more outwardly than an end of the second contact surface.

3. The circuit breaker of claim 2 , wherein the first contact surface is configured as a curved surface with an arcuate shape.

4. A circuit breaker in which a trip mechanism and a movable contact are connected respectively to both ends of a main shaft, the main shaft rotatably installed in a main body, so as to perform a trip operation by transferring a tensile force of the trip mechanism to the movable contact, the circuit breaker comprising:

a stopping groove engaged with part of the main shaft; and

a rebound preventer rotatably installed in the circuit breaker,

wherein the stopping groove comprises first and second contact surfaces contactable with the part of the main shaft upon the rotation of the main shaft, wherein an extending line of a force applied from the part of the main shaft to the second contact surface passes through the center of the rotation of the rebound preventer upon a reverse rotation of the main shaft.

5. The circuit breaker of claim 4 , wherein the main shaft is provided with a protrusion inserted into the stopping groove upon the forward and reverse rotations thereof.