Title:
Rotary drilling tool
United States Patent 2511991
US Patent References:
Rotary-core drill bit
- - 1572349
Ever-sharp drill
- - 1610569
Core-drill bit
- - 1676887
Cutting and forming tools, implements, and the like
- - 1887372
Method of making and hardening steel tools provided with hard metal members
- - 1902513
Rotary-core drill bit
- - 1572349
Ever-sharp drill
- - 1610569
Core-drill bit
- - 1676887
Cutting and forming tools, implements, and the like
- - 1887372
Method of making and hardening steel tools provided with hard metal members
- - 1902513
Inventors:
Leon, Nussbaum
Publication Date:
06/20/1950
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Export Citation:
Assignee:
Leon, Nussbaum
Primary Class:
Other Classes:
76/108.100
International Classes:
E21B10/48; E21B10/46
US Patent References:
Foreign References:
| GB453344A | ||||
| FR687791A |