| US Patent: 506,261 
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| Wrench | 
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| Patentee: |  |
 | Helfred John Rosenberg (exact or similar names) - St. Louis, MO |  
 
 
 
 
| Manufacturer: |  | Not known to have been produced |  
 
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| Patent Dates: |  
| Applied: | Apr. 08, 1893 |  
| Granted: | Oct. 10, 1893 |  
 
USPTO (New site tip)| Patent Pictures: |  |  |  | Helfred John Rosenberg patent October 10, 1893 |  Google Patents
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                        Stan Schulz
 
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| Description: |  | The two sections slide in relation to each other in a dovetail slide; the "lower" section has rack teeth cut in one edge.  A sliding toothed "dog" engages the rack teeth holds the adjustment. |  |