| 摘要 |
A reversible ratchet wrench has a housing containing a ratchet wheel and a pawl selectively pivotal between first and second conditions, respectively engageable with the ratchet wheel for accommodating rotation thereof in opposite directions, with the pawl undergoing a ratcheting movement in response to rotation of the ratchet wheel. The pawl is biased by either a torsion band or an over-center leaf spring to the selected condition. A reversing member has a lever arm pivotally movable between first and second positions to pivot the pawl. The pawl and the reversing member respectively have first and second drive portions thereon which respectively form diametrically opposed sectors of a common cylinder, each less than 180 DEG in extent, so as to define a clearance therebetween when the reversing member is in either its first or second position, the second drive portion being engageable with the first drive portion after lost motion through the clearance distance to shift the pawl between its first and second conditions. The clearance between the first and second drive portions is sufficient to accommodate ratcheting movement of the pawl without movement of the reversing member. The lever arm is flexible and resilient and has a cam following finger engageable with a cam surface on the wrench housing to resiliently resist movement of the reversing member from its first or second position. |
