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. 13, 1988
Filed:
Jun. 26, 1986
John Fuller, Penzance, GB;
Abstract
A rotary drill bit for use in coring holes in subsurface formations comprises a bit body having a shank for connection to a core barrel, an outer peripheral gauge portion for engagement with the peripheral wall of the hole being drilled, an inner peripheral gauge portion defining at least a part of a central, generally circular aperture extending axially through the bit body, a plurality of cutting elements mounted at the surface of the bit body, and passages in the bit body for delivering drilling fluid to the surface of the bit body. Hydraulic sealing means are provided on the inner gauge portion of the bit and, in use, engage the outer surface of the core being cut by the bit. The hydraulic seal thus formed prevents or restricts flow of drilling fluid in an axial direction between the inner gauge portion and the core, and thus substantially reduces erosion of the core.