Patent ID: 8710390

Claim:
In a vacuum circuit breaker comprising: an enclosure having terminals connectable to an electric power source or an electric load; a breaker body movable to a connection position for connection to the terminals of the enclosure and to a disconnection position for disconnection from the terminals of the enclosure; and a closing spring installed in the breaker body and having an extended position and a contracted position, the extended position where elastic energy is charged to move the breaker body to a closing position, and the contracted position where elastic energy is discharged, an interlock apparatus for the vacuum circuit breaker comprising: a pair of hindering units fixed to both side walls of the enclosure with a predetermined spacing distance, and configured to allow or prevent a motion of the breaker body to the connection position or the disconnection position by passing only an object having a width smaller than the predetermined spacing distance therethrough; a pair of first interlock bars horizontal-movably installed at the breaker body, and configured to change a width of the breaker body to be greater than the predetermined spacing distance of the hindering units in a first position where the first interlock bars are spaced from each other, or to change the width of the breaker body to be smaller than the predetermined spacing distance of the hindering units in a second position where the first interlock bars return to be close to each other; and a second interlock bar vertical-movably installed at the breaker body, and up-down movable to an up position and a down position by a pressing or releasing operation of the closing spring according to the extended or contracted position, the up position for moving the first interlock bars to the first position in a pressing manner by being interposed between the first interlock bars, and the down position for returning the first interlock bars to the second position by being separated from the interposed position between the first interlock bars.