| 摘要 |
PROBLEM TO BE SOLVED: To provide a boom extension device of crane that secures interlock function that prevents both lock pin and grip pin from being detached. SOLUTION: The boom extension device of crane includes: a locking/unlocking operation device that operates a lock member from a position where a lock member 61 for locking multistage extension type booms with one another to a position where the lock member releases the booms from one another; a first interlock member 121 which is moved by the lock member when the lock state by means of the lock member is released; and a second interlock member 128 which is moved by the grip member when the grip state by means of the grip member 51 is released. A moving area of the first interlock member and a moving area of the second interlock member cross each other. The first interlock member and the second interlock member are prevented from simultaneously entering the crossing area at the same time. Boom retention by means of the grip member and boom connection by means of the lock member are not released at the same time. COPYRIGHT: (C)2012,JPO&INPIT |
