06311792 is referenced by 153 patents and cites 9 patents.

A clamp for gripping casing strings is disclosed. A series of radially arranged spring biased slips are mounted in a housing attached to a top drive. A hydraulic system is used to release the slips from the gripping position upon a casing string.

Title
Casing clamp
Application Number
9/414482
Publication Number
6311792 (B1)
Application Date
October 8, 1999
Publication Date
November 6, 2001
Inventor
Kevin Nikiforuk
Calgary
US
Stephen F Scott
Calgary
US
Agent
Bennett Jones
US
Assignee
Tesco Corporation
US
IPC
E21B 17/02
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