Patent ID: 8549977

Claim:
An apparatus for opening and closing a breech block, the apparatus comprising: a cam follower connected to a breech block for opening and closing a cartridge chamber of a cannon barrel, and rotating so as to open and close the breech block; a housing mounted to a bracket; a first plunger mounted in the housing, and disposed to be moveable in one direction; a rotation unit rotatably mounted to the bracket; an intermediate unit coupled to the rotation unit, inserted into the housing, and configured to press the first plunger when the rotation unit rotates; an open cam coupled to the rotation unit, and moveable by rotation of the rotation unit between a first state for guiding rotation of the cam follower and a second state which is out of the range of a moving path of the cam follower; a first elastic member installed in the housing, and configured to support the first plunger such that a restoration force is applied to the rotation unit; and a second plunger moveably mounted in the housing, and configured to support the intermediate unit in the second state by movement of the second plunger.