| 摘要 |
<p>A wrench has a head portion (10) adapted to engage and apply torque to a workpiece, including a ring member (14) which surrounds the workpiece and has a fixed end (16) and a free end (18) such that, when the ring engages a workpiece and a torque is applied in a predetermined direction (48), the ring closes around the workpiece, increasing the grip between the wrench and the workpiece even if the workpiece is substantially worn, damaged or undersized.</p> |
