| 摘要 |
<p>To provide an electrical conduction mechanism which prevents dust or the like from adhering to the inside of an electrical-conduction portion main body (11), so that electrical conduction efficiency cannot be reduced. The electrical conduction mechanism (1) comprises an electrical-conduction portion main body (11) in the center of which a first through-hole(12) to be inserted through by a shaft (22) is formed and in which a second through-hole (13) communicating with the first through-hole (12) is formed in a direction perpendicular to a direction in which the first through-hole is formed; and an electrical-conduction element (15) disposed in the second through-hole (13). The electrical-conduction element (1) is configured to include an electrical-conduction chip (16) abutting on the shaft (22), and a coil spring (17) biasing the electrical-conduction chip (16) toward the shaft (22), so that current is supplied to the shaft (22) through the electrical-conduction chip (16) to conduct electricity to the bit (25).</p> |
