| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic fastener capable of switching a rotating speed of a bit 12 just before a head part 51 is seated, regardless of an unfitted state or a fitted state of the bit 12 and the head part 51.SOLUTION: The automatic fastener is constituted of a fastening tool 10 having the bit 12 fittable to the head paret 51 and a driving shaft 31 for transmitting rotation to the bit 12 and arranging a spring 14 for always biasing the bit 12, a lifting part 20 for reciprocatably supporting the fastening tool 10 and control means for controlling switching driving of the rotating speed of the bit 12 on the basis of the lifting part 20 and a height (c) of the lifting part 20. An abutting member 11 inserted into the bit 12 and abutting on the head part 51, is fixed to one end of the driving shaft 31 in the fastening tool 10. Thus, the rotating speed of the bit 12 can be switched to a low speed with an upper surface height of the head part 51 as a reference. |
