| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide excavating equipment capable of performing ground excavation difficult due to an underground obstacle and the like. <P>SOLUTION: In the case of an excavation means employing a crushing system, an excavation bit 1 for use in excavating equipment is rotatively driven in a state in which a top surface portion 10 of a rotary bit 6, extended portions 11 thereof and protruded portions 12 thereof are flush with one another, so as to excavate a hole with a diameter larger than an outside diameter of a steel pipe 2. In the case of an excavation means employing a cutting system or in the case of replacement and repair, the respective extended portions 11 and protruded portions 12 of rotary-bit half bodies 7 and 7 of the rotary bit 6 are turned upward by a set angle and brought into the state of being positioned inside with respect to an inside diameter of the steel pipe 2. Thus, the operation of pulling back the excavation bit 1 into the steel pipe 2 and a starting pit (in the replacement and repair or the like), or cutting-system excavation by a crown bit 3 in the state of pulling back the excavation bit 1 into the steel pipe 2 can be freely performed. <P>COPYRIGHT: (C)2012,JPO&INPIT |
