06953096 is referenced by 119 patents and cites 450 patents.

The present invention generally relates to an apparatus and method of forming a wellbore. In one aspect, an expandable bit for use in a wellbore is provided. The expandable bit includes a body and a blade assembly disposed on the body. The blade assembly is movable between a closed position whereby the expandable bit has a smaller outer diameter and an open position whereby the expandable bit has a larger outer diameter. The expandable bit further includes a release assembly for providing a secondary means to move the blade assembly from the open position to the closed position. In another aspect, a method of forming a wellbore is provided. In yet another aspect, an expandable apparatus for use in forming a wellbore is provided.

Title
Expandable bit with secondary release device
Application Number
10/335957
Publication Number
6953096 (B2)
Application Date
December 31, 2002
Publication Date
October 11, 2005
Inventor
Kenneth J Dalrymple
Perth
AU
Mark S Fuller
Scotland
GB
Andrew D Gledhill
Scotland
GB
Agent
Moser Patterson & Sheridan L
Assignee
Weatherford Lamb
TX, US
IPC
E21B 047/01
E21B 007/20
E21B 007/20
E21B 010/32
E21B 010/32
E21B 010/60
E21B 007/20
E21B 019/00
E21B 010/66
E21B 043/10
E21B 007/06
E21B 019/16
E21B 019/16
E21B 019/16
E21B 019/16
E21B 023/00
E21B 004/18
E21B 033/14
E21B 007/06
E21B 007/18
E21B 007/06
E21B 007/00
View Original Source