Patent ID: 8528219
Filing Date: 2013-09-10
Classification: E21B,G01C

Abstract:
1. A downhole tool for measuring and communicating inclination of a portion of a drill string comprising: a housing having an inner surface and a flow conduit therein for a flow of drilling fluid therethrough, the flow conduit having a plurality of passage restrictions therein; a knob movable axially within the flow conduit wherein the knob is adapted to interact with the passage restrictions to cause a flow restriction when the knob is adjacent one of the passage restrictions; a biasing mechanism adapted to bias the knob in a first direction; wherein the knob is movable axially upon the influence of the flow of drilling fluid in a second direction wherein the second direction is opposite the first direction; wherein the knob is operably connected to an upper shaft; a plurality of discs operably connected to the upper shaft, wherein at least some of the plurality of discs have an upper surface which is angled with respect to the axis of the upper shaft at successively increasing angles; one or more balls disposed on the plurality of discs, a catch pocket located within the inner surface of the housing, wherein sufficient inclination of the downhole tool causes at least one of the balls to move from a non-engaged position to an engaged position where the ball engages the catch pocket to arrest the upper shaft from axial movement in the first direction; and a dampening mechanism adapted to dampen movement of the upper shaft in at least one axial direction.