| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a bit for drilling which is suitable for use in burial of a lock bolt and a reinforcing bar for reinforcing soil and allows the reinforcing bar or the like to be efficiently buried by a double tube type method, and to recover a body of the bit for drilling except for a part. <P>SOLUTION: The bit for drilling includes: a bit body for which a recessed part is provided on a distal end center part, a blade body is planted around it, and a screw part to be screwed to a screw part of a pipe rod is provided on a rear part; and a lost bit which has a blade body planted at a distal end part and is attached to the bit body. On a rear end part of the lost bit, coupling means attachable to the distal end part of the rod inserted into the pipe rod is provided. As the coupling means at the rear end part of the lost bit, for instance, screw type coupling means can be adopted. <P>COPYRIGHT: (C)2013,JPO&INPIT |
