| 摘要 |
<p>A fluid-operated tool for tightening and loosening threaded connectors has a ratchet unit including a ratchet (6) connectable with a threaded connector to be tightened and loosened and provided with a plurality of teeth, and a pawl (9) engageable with, and disengageable from, the teeth of the ratchet, drive means (1-4, 13) movable over an advance stroke to turn the ratchet when the pawl engages the teeth of the ratchet so as to turn a threaded connector connected with the ratchet for tightening or loosening, and a retract stroke in which the pawl (9) is disengaged from the teeth of the ratchet, and a unit for sensing when the pawl falls into engagement with a tooth of the ratchet and in response reversing the drive from the retract stroke to the advance stroke.</p> |
