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:
Apr. 03, 1990
Filed:
Jul. 20, 1988
Floyd W Becker, Calgary, CA;
Drill Systems International Ltd., Calgary, CA;
Abstract
An inner pipe member for a dual-wall drill pipe assembly having an inner pipe member and an outer pipe member, the outer pipe member having a main bore extending axially therethrough including a first bore and a concentric second bore of smaller diameter than the first bore and axially spaced therefrom by a shoulder, and a circumferential recess in the second bore, the inner pipe member comprising a tubular body portion adapted to be telescopically and concentrically received in the main bore and define an annular fluid passage therewith, a first spacer at one end of the body portion for concentrically spacing the one end of the body portion from the other end of the outer pipe member, and a second spacer at the other end of the body portion, the second spacer including first and second surfaces adapted to be received in sliding fit relation within the first and second bore, respectively, for concentrically positioning the other end of the inner pipe member within the outer pipe member, and a projection extending radially outwardly of the second surface and adapted to be received in the recess when the inner pipe member is operatively disposed within the outer pipe member, the projection having an outer surface slidable in the second bore in interference fit relation therewith.