04877093 is referenced by 1 patents and cites 13 patents.

A spring actuated guide system for a top driven drilling machine. Rollers for guiding the drilling machine are mounted onto springs which urge the rollers into contact with support surfaces on parallel tracks within a derrick. If the tracks become misaligned, the springs allow for the misalignment with low roller loads thereby providing limited rotational movement of the drilling machine relative to the tracks. Premature failure of the roller bearings is prevented and wear on the rollers and tracks is reduced.

Title
Spring actuated power swivel support rollers
Application Number
7/163583
Publication Number
4877093
Application Date
March 3, 1988
Publication Date
October 31, 1989
Inventor
Leroy R Rateike
Rockford
IL, US
James E Lynch
Dallas
TX, US
David B Ford
Frisco
TX, US
Agent
R H Johnson
L A Fillnow
R J Bunyard
Assignee
National Oilwell
TX, US
IPC
E21B 3/02
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