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:
Aug. 01, 1995
Filed:
Dec. 03, 1993
Louis Martin, Compiegne, FR;
Ulrich Hager, Cernoy, FR;
Poclain Hydraulics, , FR;
Abstract
This invention relates to a drive unit comprising a frame; a rotating shaft, a first fluid motor presenting a cam fixed with respect to the frame; and a cylinder block fast with the shaft driven by the first motor at a first speed of rotation. According to the invention, the shaft presents a recess conveying a drilling fluid; the cylinder block of the first motor is coaxial to the axis of rotation; drive unit comprises a second motor coupled in rotation to the shaft and driving it at a second speed of rotation higher than the first speed of rotation; a first pinion gear is fast with and coaxial to the shaft; the second motor presents an output shaft fast with a second pinion gear meshing with the first pinion gear; and the first motor is of the type with 'disengageable pistons'. One application is the production of a high-performance drilling assembly.