| US Patent: 523,020 
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| Wrench | 
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| Patentee: |  |
 | Carl Tinglof (exact or similar names) - Boston, MA |  
 
 
 
 
 
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| Patent Dates: |  
| Applied: | Feb. 14, 1894 |  
| Granted: | Jul. 17, 1894 |  
 
USPTO (New site tip)| Patent Pictures: |  |  |  | Carl Tinglof patent July 17, 1894 with HARDY and CARTER BOSTON PAT PEND. |  Google Patents
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                        Stan Schulz
 
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| Description: |  | The frame and adjustable jaw are connected by a central adjusting screw with left- and right-hand threads. Known examples marked "HARDY & CARTER BOSTON. PAT PEND." |  |