| 摘要 |
A ratchet screw driver includes a follower secured in a handle and having two ends each having a number of ratchet teeth. A barrel is engaged in the follower and has two non-circular ends for slidably engaging with two rings. The rings have ratchet teeth arranged opposite to each other for being biased to engage with that of the follower. The barrel may be rotated by the handle when the handle is rotated in an active direction, and the rings may be forced away from the follower against the biasing springs when the handle is rotated in a reverse direction.
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