07416029 is referenced by 109 patents and cites 21 patents.

A downhole tool which can perform a task in a well bore, such as circulating fluid radially from the tool. The function is selectively performed by virtue of a sleeve moving within a central bore of the tool. Movement of the sleeve is effected by dropping a ball through a ball seat on the sleeve. Movement of the sleeve is controlled by an index sleeve such that the tool can be cycled back to the first operating position by dropping identical balls through the sleeve. Embodiments are described wherein the balls are deformable, the seat is deformable and the seat provides a helical channel through which the ball passes.

Title
Downhole tool
Application Number
10/551678
Publication Number
7416029 (B2)
Application Date
March 31, 2004
Publication Date
August 26, 2008
Inventor
James Edward Atkins
Aberdeen
GB
Rae Andrew Youngor
Aberdeenshire
GB
Edward Docherty Scott
Cardenden
GB
George Telfer
Aberdeen
GB
Agent
Osha Liang
Assignee
Specialised Petroleum Services Group
GB
IPC
E21B 34/00
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