| 摘要 |
A screw tightening apparatus comprising a motor-driven tool, a screw magazine for screws affixed to a strip-like carrier, and a screw advancing and tightening means for advancing the screws one at a time to a standby position in which a motor-driven bit may engage the screw for applying the same. A bell crank has a spring arm for advancing the screw strip and a drive arm driven by a projection on a plunger against the force of a feed spring to a cocked position, preparatory to advancement of the screw strip, the cocked position being maintained by a pivoted pawl which has a hook that locks the bell crank in such cocked position. A second projection on the plunger member engages the pawl to effect unlocking thereof near the end of a retracting stroke of the plunger member, whereby the feed spring drives the bell crank to advance the strip. A novel means for unlocking a spring-loaded axially slidable lock sleeve is provided. Further, a punch and die structure surround the screw head and cut a washer-like portion from the strip as the screw is applied. |
