Title:
Method and apparatus for controllably drilling off-vertical holes
United States Patent 3285350


Inventors:
Keller, Henderson John
Application Number:
US36210064A
Publication Date:
11/15/1966
Filing Date:
04/23/1964
Assignee:
Keller, Henderson John
Primary Class:
Other Classes:
175/40, 175/62, 340/853.8
International Classes:
E21B7/06; E21B7/08
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