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:
Feb. 26, 2002
Filed:
Feb. 03, 2000
Boulet Jean Gilbert, Paris, FR;
S.M.F. International, Cosne sur Loire, FR;
Abstract
The profiled element or portion ( ) exhibits a shape which is overall of revolution with straight or curved generatrices and an axis directed along the axis of rotation of drilling. It includes projecting parts or ribs ( ) and recessed parts or grooves ( ) arranged in helixes with, as their axis, the axis of the rotary drilling. Over at least part ( ) of the length of the profiled element ( ) in the axial direction, at least one of the geometric and dimensional characteristics of the recessed parts ( ) and of the projecting parts ( ) varies in the axial direction of the profiled element ( ). As a preference, the profiled element ( ) includes, in at least one variable profiled part ( ), passages in the shape of grooves ( ) with a cumulative cross section which decreases in a direction of flow of the drilling fluid. This thus yields a hydrodynamic bearing effect, by forming a circumferential leakage flow ( ) of the drilling fluid.