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:
Oct. 22, 1991
Filed:
Oct. 19, 1990
Stephen M Collinsworth, Stanton, KY (US);
Other;
Abstract
A drill bit sub, which has a drill bit with three equally angularly spaced cutters releasably threaded into its bottom surface, has its lower portion reduced in diameter. A protective sleeve, which is a hollow cylindrical metal tube, is releasably attached to the lower portion of the drill bit sub so that three equally angularly spaced lugs are at specific circumferential positions relative to the cutters. The lugs engage three equally angularly spaced wear strips on a wear strip support, which is mounted on the lower portion of the drill bit sub below the protective sleeve, so that the wear strip support rotates with the drill bit sub. The drill bit bears against the lower end of the wear strip support when the drill bit is mounted on the drill bit sub. The specific positions of the lugs on the protective sleeve align each of the three wear strips with the maximum outer protrusion of one of the three cutters on the drill bit. A break out ring may be mounted on the lower portion of the drill bit sub above the protective sleeve. The lower portion of the drill bit sub may have air passages extending from its outer surface to an axial passage through which compressed air passes so that dust cannot build up between the lower portion of the drill bit sub and each of the protective sleeve and the wear strip support.