PROBLEM TO BE SOLVED: To enable to detect a boom hoisting rocking position before a lateral feed pipe reaches a predetermined stopping position in a descending side, as well as install a device for detecting the boom hoisting rocking position in a state with little interference with other objects and with easily carrying out maintenance work of the same.SOLUTION: The device 6 for detecting the boom hoisting rocking position for detecting the boom hoisting position of a vertical feed pipe 55 and a lateral feed pipe 56 constituted so as to be freely rockable around a rocking shaft center x in the horizontal direction on the upper end side of the vertical feed pipe 55 is installed on the side of a downward facing plane at connection points 55D, 56D of the vertical feed pipe 55 and the lateral feed pipe 56.COPYRIGHT: (C)2010,JPO&INPIT【課題】横送り筒が下降側の停止予定箇所へ到達する前にその起伏揺動位置を検出するできるようにするとともに、起伏位置検出装置を、他物と干渉する可能性の少ない状態で、かつ、メンテナンス作業も行い易い状態で設ける。【解決手段】縦送り筒55と、その縦送り筒55の上端側における水平方向の揺動軸心x周りで起伏揺動自在に構成された横送り筒56の起伏揺動位置を検出する起伏位置検出装置6を、前記縦送り筒55と横送り筒56との接続箇所55D,56Dにおける下向き面側に設けてある。【選択図】図5
