| US Patent: 661,011 
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| Pipe and Nut Wrench Involute Wrench
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| Patentee: |  |
 | Maschil D. Converse (exact or similar names) - New York, NY |  
 
 
 
 
 
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| Patent Dates: |  
| Applied: | Jun. 07, 1900 |  
| Granted: | Oct. 30, 1900 |  
 
USPTO (New site tip)| Patent Pictures:
	      
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	        ] |  |  |  | Maschil D. Converse Pat. Oct. 30, 1900 |  Google Patents
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                        Stan Schulz
 
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| Description: |  | "A wrench with a rigid arc-shaped fulcrum jaw, and a rigid circumscribing jaw ... the teeth on the circumscribing jaw shall be ranged on a true involute line ... " 
A December 1906 HARDWARE DEALERS' announcement notes two sizes; No. 1 at 5 1/2 inches and No. 2 at 9 inches. The larger size is far less common than the No. 1 size. 
The STEEL CITY ELECTRIC CO RED HEAD wrench looks similar, but appears to be based on patent no. 1,896,437. |  |