Title:
Electric boring apparatus
United States Patent 2822148

Inventors:
Murray, Robert W.
Publication Date:
02/04/1958
View Patent Images:
Download PDF 2822148 pdf       PDF help
Export Citation:
Click for automatic bibliography generation
Assignee:
Murray, Robert W.
Primary Class:
175/15
Other Classes:
175/106, 175/16, 175/393, 175/104, 175/97, 175/421, 175/100
International Classes:
E21B7/15; E21B7/14
US Patent References:
2308860Means of drilling rock, concrete, and the like
2482473Arc welding apparatus
2548463Thermal shock drilling bit
2628817Rock piercing blowpipe
2637527Well drilling device
2659036Alternating current arc welding equipment