| 摘要 |
PROBLEM TO BE SOLVED: To provide a specific position retaining apparatus of a cutting tool which enables to make a hole in a concrete structure and the like in a short time using a small cutting tool such as a concrete cutter. SOLUTION: The specific position retaining apparatus 1 comprises an apparatus main body has a base 10 to be fixed at a predetermined position and a strut 20 fitted thereto and an arm member 30 for attaching a cutter 5 rotatably and movably back and forth along the strut 20, which member is installed on the strut 20. When the apparatus 1 is used, the base 10 is fixed at a predetermined position and the arm member 30 is advanced to the cutting position on the cutting object W (manhole) to form a slit. Then, after it is retracted and rotated in a given angle, the arm member 30 is advanced to the next cutting position adjacent to the previously formed slit to form the next slit. By repeating this operation, an annular string of slits is formed and a hole is formed. COPYRIGHT: (C)2004,JPO
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