| US Patent: 208,059 
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| Wrench | 
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| Patentee: |  |
 | John S. Birch (exact or similar names) - Orange, NJ |  
 
 
 
 
| Manufacturer: |  | Not known to have been produced |  
 
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| Patent Dates: |  
| Applied: | Mar. 12, 1878 |  
| Granted: | Sep. 17, 1878 |  
 
USPTO (New site tip)| Patent Pictures: |  |  |  | John S. Birch patent September 17, 1878 |  Google Patents
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                        Stan Schulz
 
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| Description: |  | The wrench is self-adjusting; the movable jaw tends to close under the pressure of a compression spring.  It is held in position by a toothed cam that bears against an extension of the movable jaw.  The cam has side grips to rock it back to release its grip to readjust the wrench. |  |