| 摘要 |
PROBLEM TO BE SOLVED: To enhance work efficiency and achieve cost reduction by effectively faster eliminating concrete slag completely stuffed in a P-Con by adding no pushing-in force and reducing load to an arm and fatigue. SOLUTION: In a tubular drill having a connecting portion mounted on the base end side of the tubular drill main body and a cog portion formed on the tip end of the tubular drill main body, a screw portion screwing on a supporting screw portion of the tip end of the P-Con supporting bolt is mounted in the predetermined deep end of the tubular drill main body. COPYRIGHT: (C)2006,JPO&NCIPI
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