| US Patent: 354,770 
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| Wrench | 
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| Patentee: |  |
 | Matthew E. Campfield (exact or similar names) - Sterling, OH |  
 
 
 
 
| Manufacturer: |  | Not known to have been produced |  
 
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| Patent Dates: |  
| Applied: | Mar. 25, 1886 |  
| Granted: | Dec. 21, 1886 |  
 
USPTO (New site tip)| Patent Pictures: |  |  |  | Matthew E. Campfield patent Dec. 21, 1886 |  Google Patents
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                        Stan Schulz
 
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| Description: |  | A lever in the base of the movable jaw raises and lowers a toothed pawl. The internal linkage and compression spring act to keep the pawl engaged with rack teeth cut in the face of the shank. This design allows for one-handed operation.
Ken Cope's "American Wrench Makers 1830-1930" speculates the Sterling Wrench Company may have produced this Campfield patent. |  |