| US Patent: 336,468 
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| Pipe Wrench | 
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| Patentees: |  
 | Christian Bonnichsen (exact or similar names) - Newburgh, NY |  | Michael R. Chrystal (exact or similar names) - Newburgh, NY |  
 
 
 
 
| Manufacturer: |  | Not known to have been produced |  
 
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| Patent Dates: |  
| Applied: | Oct. 29, 1885 |  
| Granted: | Feb. 16, 1886 |  
 
USPTO (New site tip)| Patent Pictures: |  |  |  | Christian Bonnichsen and Michael R. Chrystal patent February 16, 1886 |  Google Patents
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                        Stan Schulz
 
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| Description: |  | The gripping portion is alternately a chain or semi-circular jaws.  Either form is connected to the handle by a swinging link. |  |