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:
Dec. 27, 1988
Filed:
Mar. 16, 1988
Applicant:
Inventor:
Igor Krasnov, Houston, TX (US);
Assignee:
Hughes Tool Company - USA, Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175 57 ; 175 85 ; 175113 ; 294 90 ; 414 2251 ;
Abstract
An apparatus for a top drive drill rig lifts a stand of the drill pipe into engagement with the drive stem in the derrick. The apparatus includes a set of elevators mounted between the drive head by a link assembly. The link assembly includes two link sections connected together by a swivel joint. An upper hydraulic cylinder is connected between the drive head and the upper link section. A lower hydraulic cylinder is connected between the upper and lower link sections. These cylinders may be retracted to pull the stand of drill pipe upward into contact with the drive stem.