Angle deviation tool

Claim 1

A drilling assembly usable downhole on fluid conducting drill strings, situated in earth boreholes for selecting straight hole or directional drilling configuration of the downhole assembly by manipulation, at the earth surface, of drilling fluid flow controls, apparatus comprising: (a) a body with an upper end with connector means to attach to the upwardly continuing drill string, and a lower end with means to attach to the downwardly continuing drill string, and at least one fluid conducting channel to conduct fluid between said portions of the continuing drill string, each end of said body having an independent longitudinal centerline; (b) control selector means within said body in communication with said channel responsive to a first preselected number of increases, greater than a preselected amount, of the fluid flow rate through said channel to produce a first output signal, and responsive to a second preselected number of increases, greater than a preselected amount, of the fluid flow rate through said channel to produce a second output signal; (c) means at the earth surface to cycle said drilling fluid flow rate between higher and lower flow rates; and (d) hinge means in said body responsive to said first output signal to cause said centerlines to generally coincide, and responsive to said second output signal to cause said centerlines to produce an effectively bent overall body centerline.