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. 23, 1990
Filed:
Nov. 18, 1988
William N Schoeffler, Lafayette, LA (US);
Other;
Abstract
An improved directional drilling tool permits changing the downhole drilling assembly between straight and directional drilling configuration by manipulation of conventional drilling fluid flow controls at the surface. A housing, with stabilizer features, shrouds a shaft which functions as an extension of the drill string and attaches to a drill head. A drilling fluid flow rate responsive selector valve is situated in the shaft and responds to drilling fluid flow rate manipulations to change assembly configuration. In the straight configuration the shaft remains straight and is rotationally locked to the housing. In the directional configuration the housing is rotationally unlocked from the shaft, normally after directional orientation, so that the shaft can rotate through it. The same action transversely displaces the shaft midsection relative to the housing and the shaft and drill head below is angularly deflected by way of a hinge arrangement near the drill head end of the housing. The process can be reversed for straight drilling by further drilling fluid flow rate manipulations.