| 摘要 |
<p>An air impact screwdriver (1), wherein a slidable contact nose (12) is fitted to a nose (5) to switchingly operate a contact valve (23) by the contact nose, and an AND circuit for switching between an air motor control pilot valve (39) and a piston control pilot valve (41) is formed of a trigger valve (8) operated by a trigger lever (9) and the contact valve (23), the air impact screwdriver is started for screwing when the contact noise is pushed in and the trigger lever is pulled, and, to further tighten a screw, the contact valve is turned off after the start to stop a screwdriver bit (15) at a bottom dead center and the contact nose is pushed in with the screwdriver bit fitted to the recess in the screw to re-start the screwdriver bit.</p> |
