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. 18, 1995
Filed:
Apr. 08, 1993
Robert F Kane, Harris, TX (US);
Matthew Shofner, Fort Bend, TX (US);
Faisal J Yousef, Harris, TX (US);
Kenneth Ahlhorn, Harris, TX (US);
Sandvik Rock Tools, Inc., Bristol, VA (US);
Abstract
A down-the-hole hammer drill having a reverse circulation system which conducts pressurized air downwardly to a lower cutting face of a drill bit. The air travels across the cutting face and upwardly through a central exhaust passage. The air is conducted to the cutting face through longitudinal and lateral passages in the bit which are kept isolated from the environment surrounding the bit so that no appreciable amount of pressurized air can escape, and so that the passages do not become clogged with dirt. The drill bit comprises upper and lower pieces. Upper sections of the longitudinal passages are formed in the upper piece, and lower sections of the longitudinal passages are formed in the lower piece.