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.

Date of Patent:
Dec. 18, 2001

Filed:

Mar. 12, 1999
Applicant:
Inventors:

John Timothy Allen, Katy, TX (US);

Steven Anthony Box, Katy, TX (US);

Assignee:

Weatherford/Lamb, Inc., Houston, TX (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B 1/916 ;
U.S. Cl.
CPC ...
E21B 1/916 ;
Abstract

A tong for rotating tubulars, the tong having, in certain embodiments, a tong outer case, a rotary movably mounted in the case for rotating a tubular, apparatus for rotating the rotary to rotate the tubular, at least one gripper or jaw movably mounted in the case and movable by the rotary for gripping the tubular, the at least one gripper or jaw having at least one cam following member or roller, and at least one non-circular cam surface on the rotary, the at least one cam following member or roller contacting and movable on the at least one non-circular cam surface for maintaining a desired position of the at least one gripper or jaw with respect to the tubular. In certain embodiments a specific cam angle, within certain tolerances, is maintained substantially the entire length along a cam surface.


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