To provide a screw driver reliably stopping a bit to stabilize a fastening depth of a screw.
In the screw driver including a rotary part 4 having a bit 1A engageable with a screw and rotated by an air motor 31, a housing 21 rotatably holding the rotary part 4, and a clutch mechanism 8 interposed between the rotary part 4 and the housing 21, the rotary part 4 has a sub piston part 6 moved from an upper dead point to a lower dead point by compressed air and including the bit 1A, the clutch mechanism 8 has an outer clutch plate 81 mounted on the housing 21 non-rotatably around the shaft and an inner clutch plate 82 mounted on the bit 1A to be rotated coaxially and integrally with the rotary part 4 and the outer clutch plate 81 and the inner clutch plate 82 are positioned to be urged by the sub piston part 6 and pressed together to come in surface contact with each other when the sub piston part 6 reaches the lower dead point.
KOMAZAKI GIICHI
| JP2004090146A | 2004-03-25 | |||
| JPH06143079A | 1994-05-24 | |||
| JP2000094360A | 2000-04-04 |
Shin Koizumi
Akiko Ichikawa
Kunihiko Wakabayashi