The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 26, 1977
Filed:
May. 30, 1975
Applicant:
Inventors:
Leon Berthal Stinson, Houston, TX (US);
Edward Milburn Galle, Houston, TX (US);
Assignee:
Hughes Tool Company, Houston, TX (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F16C / ;
U.S. Cl.
CPC ...
308-82 ; 184-621 ; 308187 ;
Abstract
Disclosed herein is a drill bit for earth boring, including a lubrication system that eliminates necessity for a complex system to accomplish pressure compensation. Since the temperature of the earth generally increases with depth from the surface, a drill bit experiences increasing temperature with increasing depth. The coefficient of thermal expansion of lubricant inside a bit is greater than that of the metal defining the walls of the lubricant cavities. Internal bearing lubrication pressure control is achieved utilizing thermal expansion of the lubricant, seal displacement, and a pressure relief valve.