| US Patent: 596,505 
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| Pipe Wrench | 
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| Patentee: |  |
 | John A. Hawthorn (exact or similar names) - Lancaster, PA |  
 
 
 
 
| Manufacturer: |  | Not known to have been produced |  
 
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| Patent Dates: |  
| Applied: | Sep. 30, 1896 |  
| Granted: | Jan. 04, 1898 |  
 
USPTO (New site tip)| Patent Pictures: |  |  |  | John A. Hawthorn patent January 4, 1898 |  Google Patents
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                        Stan Schulz
 Hawthorn's Wrench For Large Pipes (March 18, 1898)
 
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| Description: |  | The thumb screws adjust the grip just tight enough so the teeth will grip as the wrench is moved in one direction, but slip on the return movement. The teeth are shaped to grip in one direction and slide on return movement. The "knee joint" in the main shank likewise works to grip and release in coordination with the biting direction of the teeth.
A description of the wrench appears in the March 18, 1898 "English Mechanic and World of Science." |  |