| 摘要 |
PURPOSE:To prevent danger by intervening an insulator at the linking portion between a motor and a working portion and by electrically connecting said motor and said working portion by a high-resistance resistor, thereby flowing out a static electricity which has been generated in the working portion. CONSTITUTION:Insulation is achieved by intervening a ring-shaped insulating tube 7 having a ring-shaped collar 5 between linking portions 8 and 9 which connect a motor 1 and a working portion 4 comprising a twist drill which is driven by said motor and the like. A high-resistance resistor 10 whose resistance is 100kOMEGA or more is installed in the ring-shaped collar 5, and connecting terminals 11 and 12 are connected to the linking portions 9 and 8. In this constitution, low-voltage currents are blocked, but high-voltage-currents of static electricity are conducted, thereby worker's unpleasant feeling and danger can be elemented. |
