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:
Mar. 06, 1979
Filed:
Oct. 25, 1977
Robert L Dixon, Brea, CA (US);
Malcolm D Maxsted, Harbor City, CA (US);
Jackson M Kellner, Midland, TX (US);
Smith International, Inc., Newport Beach, CA (US);
Abstract
A raise drill is disclosed for enlarging a pilot hole into a large diameter hole by disintegrating the earth formations surrounding the pilot hole. The raise drill includes a bit body having a plurality of roller cutters mounted thereon. The bit body is detachable secured to a drive stem to permit removal and replacement of the stem. A shock absorbing element is interconnected between the drive stem and the bit body to enable the bit body to be flexibly mounted on the drive stem. A central yoke is provided to extend around the drive stem and interconnect the saddles of the two innermost cutters. The central yoke functions to distribute the loading of the inboard cutters. The central yoke can also function as a housing for a packing element.