| 摘要 |
PURPOSE: To provide a drilling tool with high safety which can perform drilling, peeling-off and so on for a material such as foam resin with ease and rapidity by utilizing a rotating tool and which never do severe damage even when a cutter element is brought into contact with the covering of a cable. CONSTITUTION: One end of a cutter element 3 constituted of a piano wire is embedded in a cap 2 screwed in the top end of a shank 1, and the other end of the cutter element 3 is supported by a supporting ring 4 rotatably-inserted in the shank 1. A contact element 5 is disposed behind the supporting ring 4, and when the cutter element 3 elastically-displaces smaller than a hole diameter, the contact element 5 is brought into contact with the wall surface of the hole. The second cutter element 8 is mounted between a front stationary ring 6 and a rear stationary ring 7 secured at the shank 1, and by the screwing advance of an adjusting ring 9, the bulging height of the second cutter element 8 can be adjusted. |
