Title:
Raise drilling method and mechanism
United States Patent 3220494
US Patent References:
Well-drilling apparatus
- - 1781707

Mining machine
- - 2320874

Drilling machine
- - 2334312

Portable drilling rig
- - 2516182

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- - 2733896


Inventors:
Cannon, Robert E.
Winberg, Douglas F.
Mccurdy, Dean K.
Robbins, Richard J.
Publication Date:
11/30/1965
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Assignee:
ROBBINS & ASSOC JAMES S
Primary Class:
175/27
Other Classes:
173/28, 173/194, 175/53, 173/4, 173/152, 175/57
International Classes:
E21B7/28; E21B7/00
US Patent References:
2775439Cutter head for driving crosscuts
2792198Portable drill rig
2856155Rotary drilling apparatus
2956782Well drilling machine
3011567Method of drilling horizontal bores employing a gel-forming colloidal drilling fluid
3088531Rock drill carrier