SEARCH:
GO TO ADVANCED SEARCH
LOGIN:
Login
Create Free Account
HOME
SEARCH PATENTS
CHEMICAL SEARCH
DATA SERVICES
HELP
Well bit protector
United States Patent 2296939
Inventors:
Mcmahan, Thomas E.
Publication Date:
09/29/1942
View Patent Images:
Download PDF 2296939
PDF help
Export Citation:
Click for automatic bibliography generation
Assignee:
Mcmahan, Thomas E.
Primary Class:
175/307
Other Classes:
175/331
International Classes:
E21B12/04
;
E21B12/00