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. 31, 1983
Filed:
Feb. 25, 1981
Floyd W Becker, Calgary, CA;
Kare Asak, Calgary, CA;
Turbo Resources Ltd., Calgary, CA;
Abstract
A double-walled drill pipe, having a plurality of outer pipe lengths connected end-to-end and a plurality of inner pipe lengths connected end-to-end and concentrically disposed within the outer pipes and defining an annular fluid flow passageway and a return flow passageway, is provided with an inner pipe support arrangement for minimizing stresses applied to the inner pipe lengths when blows are applied to the outer pipe lengths to drive a cutting bit. Each outer pipe length is provided with a ledge on its inner surface to provide a seat for an abutment on the outer surface of its adjacent inner pipe. When a blow is applied to the outer pipe lengths, the outer pipe is forced downwardly but due to inertial effects, the inner pipe unseats and is permitted to fall under its own weight. A resilient shock ring may be positioned on the length to cushion the fall of the inner pipe and provision may be made to limit axial displacement between the inner and outer pipes.