| 摘要 |
<p>A through-hole type power wrench includes a socket bracket 11, a swingable member 12, a ratchet socket 13, first 14 and second 15 pawls, and first and second resilient elements. The swingable member is disposed in the socket bracket. The pawls are swingably fixed on the swingable member and biased by the resilient elements to engage with the surface of the ratchet socket. The wrench also includes a limiting member 16 configured to isolate one of the pawls from the ratchet socket. The limiting member is formed with an opening 161, 162 adapted for allowing one of the pawls to pass through, and the limiting member is moveable about the ratchet socket between first and second positions. The opening faces towards the first and second pawls when at the first and second positions, respectively. The limiting member controls the direction of the rotation, allowing it to switch from clockwise to anti-clockwise, reversing direction. The limiting member can be C-shaped or O-shaped, producing a sickle or crescent shape, with attached lever 17. The wrench can be powered by electric or pneumatic motor; it may also be an impact wrench, with a striking mechanism comprising mandrel, hammer and anvil.</p> |
