| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent switching of the whole length of a backstop from being forgotten when switching a crane specification and a tower crane specification each other. <P>SOLUTION: The boom backstop device includes: a pair of back stops 13 with telescopic mechanism 14 each connected to an inner boom 2 of a crawler crane; a pair of support members 6 which are connected to a longitudinal-direction intermediate part of the inner boom 2 and are connected to longitudinal-direction intermediate parts of the respective back stops 13; brackets 16 for receiving end parts of the respective back stops 13, respectively deposited on the upper part of turning body 1; and a whole length switching detector 36 of a back stop which detects the extension state and the contraction state of the telescopic mechanisms 14. When switching the crane specification and the tower crane specification to each other, the extension state and the contraction state of the telescopic mechanisms 14 are detected by the whole length switching detector 36 and, therefore, the switching of the whole length of the back stop 13 can be prevented from being forgotten. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
