Ratchet wrench with lost motion reversing mechanism
US5157994A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 13, 1991 |
| Grant date | Oct 27, 1992 |
| Priority date | — |
| Expiry date | Dec 13, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B13/463
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
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.degree. 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. …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.