Title:
OIL DERRICK ERECTION AND SUPPORT SYSTEM
United States Patent 3483933


Inventors:
Dyer, Norman D.
French, Burton W.
Application Number:
US3483933DA
Publication Date:
12/16/1969
Filing Date:
11/24/1967
Assignee:
Dresser, Ind
Primary Class:
Other Classes:
52/116, 52/125.2, 254/337
International Classes:
E21B15/00; (IPC1-7): E21C9/00; B66C23/60; E21C11/00
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