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. 17, 1992
Filed:
Mar. 15, 1991
Applicant:
Inventor:
Frank R Kinnan, Camas Valley, OR (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ; E21B / ;
U.S. Cl.
CPC ...
175 61 ; 175 67 ; 175 73 ; 175320 ; 175324 ; 175424 ;
Abstract
A method and apparatus for creating an underground bore hole employing a steerable boring head at the end of a remotely driven drill string. The boring head, preformed at an angle to the longitudinal axis of the trailing pipe string to bore along a curvilinear path is straightened by increasing the pressure of the fluid within the drill string above a predetermined range to enable drilling along a linear path. Subsequent reduction of the fluid pressure to normal drilling pressure returns the boring head to its former state along a resumption of a curvilinear drill path.