03967680 is referenced by 37 patents and cites 5 patents.

A combination of means to detect rotation of a pipe string and means to detect flow of fluid through a pipe string is utilized to cause down hole apparatus to carry out preferred actions if the sequence of rotation rate change and flow rate change is of one character, other activities being carried out if different sequences occur. Alternately, a choice of several actions to be taken by down hole apparatus may be elected by sustaining a flow condition while rotational conditions are manipulated at the earth surface.

Title
Method and apparatus for actuating a downhole device carried by a pipe string
Application Number
5/493712
Publication Number
3967680
Application Date
August 1, 1974
Publication Date
July 6, 1976
Inventor
John Doise Jeter
Dallas
TX, US
Assignee
Texas Dynamatics
TX, US
IPC
E21B 3/12
E21B 23/04
View Original Source