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:
Jan. 24, 1978
Filed:
Mar. 08, 1976
Byron W Chitwood, Houston, TX (US);
Thomas E Winship, Houston, TX (US);
Reed Tool Company, Houston, TX (US);
Abstract
A rotary drill bit for producing a raise bore about a pilot hole comprises a drill head having an upper surface for mounting cutter assemblies and lower surface spaced from said upper surface. The upper and lower surfaces are secured to and connected by a body sub. A drive stem is removably secured in the drive sub. The drive sub and stem have mating tapered portions for a press fit. Either the sub or the stem is provided with a spiral groove through which oil is injected under high pressure to expand the sub while the stem is rammed into place under high pressure. The stem can be removed by application of oil pressure and a ram force in the opposite direction.