AIR CIRCUIT BREAKER HAVING AN AUTOMATIC DISCHARGING APPARATUS FOR A CLOSING SPRING

摘要

An air circuit breaker having an automatic discharging device for a closing spring is provided to protect a user from an accident by preventing charging of the closing spring due to a user's mistake when a main body is drawn from a cradle. An air circuit breaker includes a main body. A cradle(c) supports the main body. A closing spring supplies elastic energy for closing the air circuit breaker. A switching mechanism has a cam to operate the closing spring to charge or discharge the elastic energy and a cam shaft(2a) to support the cam rotatably. A cam shaft rotation restricting mechanism is installed on the cam shaft to restrict rotation of the cam shaft by elastic restoring force of the closing spring. A restriction releasing mechanism releases restriction of the cam shaft rotation restricting mechanism to rotate the cam shaft by the elastic storing force of the closing spring according to a position in which the main body is drawn from the cradle.