Sign up
Title:
Drilling machine or drilling rig
United States Patent 1649239
Inventors:
Krupp, Leo A.
Application Number:
US16229727A
Publication Date:
11/15/1927
Filing Date:
01/20/1927
Assignee:
STAR DRILLING MACHINE COMPANY
Primary Class:
Other Classes:
74/522
International Classes:
E21B1/02
View Patent Images: