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:
Sep. 08, 1987
Filed:
Aug. 16, 1984
Applicant:
Inventor:
Pierre R Fillet, Paris, FR;
Assignee:
Vallourec, Paris, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ; E21B / ; F16B / ;
U.S. Cl.
CPC ...
175320 ; 285144 ; 403369 ;
Abstract
The invention disclosed herein concerns a drill stem intended for sinking shafts in the ground, especially for the oil and natural gas industry. It has on its outer periphery a surface of revolution providing a succession of hollow profiles with a rounded shape relative to the axis of the stem, said surfaces for revolution being adapted to rest against the internal faces of complementary shape of self-gripping slips which ensure holding of the drill string.