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. 20, 1983
Filed:
Aug. 28, 1981
George I Boyadjieff, Anaheim, CA (US);
Andrew B Campbell, San Marino, CA (US);
Varco International, Inc., Orange, CA (US);
Abstract
A well drilling rig having a rotary table for driving a drill string rotatively and having jacking mechanism for lowering casing into the well after drilling, with the jacking mechanism including fluid pressure actuated piston and cylinder means which may be left in the rig during drilling and which are positioned low enough in the rig to avoid interference with operation of the rotary table. The jacking mechanism also includes a structure which is adapted to be connected to the piston and cylinder means when the casing or other well pipe is to be lowered and which is actuable upwardly and downwardly and carries one of two pipe gripping units for progressively jacking the pipe downwardly by vertical reciprocation of that structure. The reciprocating structure may take the form of a beam extending between two pistons and actuable thereby, with a second beam being connected to cylinders within which the pistons are contained and being utilized to support the second gripping element. In one form of the invention, the rotary table when in use is supported by this second beam.