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:
May. 09, 1989
Filed:
Jan. 28, 1988
Tom T Hashimoto, Conroe, TX (US);
Branham Industries, Inc., Conroe, TX (US);
Abstract
In accordance with an illustrative embodiment of the present invention, a cased borehole is drilled under surface obstructions in a single pass operation. The drilling apparatus includes a rotary drill bit mounted on a guide head having a ball joint connection to a housing. Remote controlled hydraulic cylinders enable steering of the guide head and bit, so that the hole direction can be controlled at will. Casing sections connected to the housing are added end-to-end as the borehole is lengthened, and axial thrust is applied to the casing string at the borehole entrance by a drilling rig to force the bit against the formations. The bit is driven by drill pipe that is centralized within the casing, so that when the bit, guide head and housing emerge from the ground, these elements can be disconnected, and the drill pipe pulled out of the casing to leave an unobstructed, lined borehole that is formed in a single pass.