Title:
Safety casing head for oil wells
United States Patent 1819875


Inventors:
Stokes, Cunningham Marion
Application Number:
US45518130A
Publication Date:
08/18/1931
Filing Date:
05/24/1930
Assignee:
Stokes, Cunningham Marion
Primary Class:
Other Classes:
92/72, 251/58, 251/231, 277/325
International Classes:
E21B33/06
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