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:
Dec. 20, 1983
Filed:
Dec. 04, 1981
John M Mullins, Houston, TX (US);
Hughes Tool Company, Houston, TX (US);
Abstract
An earth boring bit of the air cooled bearing type has features to improve cleaning of the borehole. The bit has three bit legs, each with a depending bearing pin that receives a rotatable cutter. Bearings are located between the bearing pin and the cutter. Passages communicate drilling fluid from the drill string to the bearings. A slot between the bit leg and the backface of the cutter enables air to be discharged from the bearing pin into the borehole. The portion of the slot on the lower side of the bearing pin is greater in cross-sectional flow area than the portion on the upper side. The portion of the slot on the lower side exposes the outer ends of the roller bearings to the borehole.