| US Patent: 131,252 
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| Improvement in Pipe-Wrenches Improvement in Self-Adjusting Pipe Wrenches
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| USPTO Classifications: |  | 81/99 |  
 
 
 
| Manufacturer: |  | Not known to have been produced |  
 
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| Patent Dates: |  
| Granted: | Sep. 10, 1872 |  
 
USPTO (New site tip)| Patent Pictures: |  |  |  | John Craig Pat. September 10, 1872 |  Google Patents
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                        Stan Schulz
 
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| Description: |  | The wrench is a swinging hook-jaw self-adjusting pipe wrench with a spring-loaded button in the base of the swinging jaw to push the jaw toward a closed position. The specifications note the shape of the hook jaw and curved face of the fixed jaw would maximize the range of sizes the wrench would accomodate. |  |