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Downhole tools are provided for measuring the inclination of a portion of a drill string. In certain embodiments, downhole tools for measuring inclination comprise a catch system for measuring inclination and a pressure pulse signaling system for communicating inclination measurement information to

Downhole tools are provided for measuring the inclination of a portion of a drill string. In certain embodiments, downhole tools for measuring inclination comprise a catch system for measuring inclination and a pressure pulse signaling system for communicating inclination measurement information to the surface. Catch systems for measuring inclination include a series of disc mounted on an upper shaft, each disc having a ball disposed thereon.

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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

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; anda dampening mechanism adapted to dampen movement of the upper shaft in at least one axial direction. 2. The downhole tool of claim 1, wherein the flow conduit comprises at least 4 consecutive passage restrictions therein. 3. The downhole tool of claim 1, wherein the biasing mechanism is a spring adapted to operably engage the upper shaft. 4. The downhole tool of claim 1, wherein each of the successive angles of the plurality of discs increases by at least 0.5°. 5. The downhole tool of claim 4, wherein the first angle is about −1°. 6. The downhole tool of claim 1, wherein the plurality of discs comprises at least six discs. 7. The downhole tool of claim 1, wherein the plurality of discs comprises at least four discs. 8. The downhole tool of claim 1, wherein a top surface of each disc in the plurality of discs respectively defines a positive angle with respect to the upper shaft of about 1°, about 2°, about 3°, and about 4°. 9. The downhole tool of claim 1, wherein a top surface of at least one disc defines an angle with respect to the upper shaft that is a negative angle such that no inclination of the upper shaft is required to cause a ball corresponding to the at least one disc to engage the catch pocket when axial movement of the upper shaft causes the ball to pass by the catch pocket. 10. The downhole tool of claim 1, wherein the catch pocket includes a sloping surface for allowing release of the ball in the second direction to allow axial movement of the upper shaft in the second direction. 11. The downhole tool of claim 1, wherein the dampening mechanism is adapted to dampen movement of the upper shaft in both axial directions. 12. The downhole tool of claim 1, wherein a disc spacing between each consecutive disc in the stack of discs corresponds to a passage restriction spacing between each consecutive passage restriction such that a passage of the knob past each passage restriction corresponds to a passage of one of the corresponding disc by the catch pocket. 13. The downhole tool of claim 1, wherein a first wiper seal is disposed above the dampening mechanism to prevent drilling mud from entering the dampening mechanism. 14. The downhole tool of claim 1, further including a fill port that is in fluid communication with the dampening mechanism. 15. A downhole tool for determining inclination of a portion of a drill string comprising: a housing having an inner surface and a flow conduit therein for the flow of drilling fluid;an upper shaft located within the housing and axially movable within the housing in a first direction and a second direction;a plurality of discs operably connected to the upper shaft, wherein each disc has a top surface angled toward the first direction which angle surface is angled with respect to the upper shaft, wherein each disc's top surface and the upper shaft define a disc/shaft angle, wherein each disc/shaft angle is different from the other angles;one or more balls disposed on the angled surface of each of the disc;a catch pocket disposed on the housing, wherein at least one of the balls may engage the catch pocket upon sufficient inclination of the upper shaft to arrest the upper shaft from further axial movement in the first direction; anda biasing mechanism adapted to bias the upper shaft in the first direction. 16. The downhole tool of claim 15 further comprising a dampening mechanism adapted to dampen movement of the upper shaft in at least one axial direction. 17. The downhole tool of claim 16, wherein the biasing mechanism is a spring adapted to operably engage the upper shaft. 18. The downhole tool of claim 15, wherein the top surface of the plurality of discs defines an angle with respect to the upper shaft and each consecutive angle differs by at least 0.5°. 19. The downhole tool of claim 18, wherein the plurality of discs comprises about four discs. 20. The downhole tool of claim 19, wherein the angle defined by the top surface of each disc ranges from −2° to greater than 10°. 21. The downhole tool of claim 20, wherein at least one top surface defines an angle with respect to the upper shaft that is a negative angle such that no inclination of the upper shaft is required to cause a ball corresponding to the at least one disc to engage the catch pocket when axial movement of the upper shaft causes the ball to pass adjacent to the catch pocket. 22. The downhole tool of claim 15, wherein the catch pocket comprises a sloping surface for allowing release of the at least one ball in the second direction to allow axial movement of the upper shaft in the second direction and wherein the catch pocket is adapted to engage the at least one ball to arrest axial movement of the upper shaft in the first direction. 23. A method for determining the inclination of a portion of a drill string relative to a gravity vector of a borehole comprising: providing a downhole tool comprising:a housing having 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 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 a upper shaft;a plurality of discs operably connected to the upper shaft, wherein a top surface of each disc is angled with respect to the upper shaft, wherein each top surface defines an angle with respect to the upper shaft, wherein each angle is different from the other angles;one or more balls disposed on each of the discs;a catch pocket;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;a dampening mechanism adapted to dampen movement of the upper shaft in at least one axial direction;introducing the flow of drilling fluid in the flow conduit to cause the knob to be displaced in the second direction to a lower position;reducing or ceasing the flow of drilling fluid to allow the biasing mechanism to displace the knob in the first direction; andallowing the one or more balls to engage the seat of the catch pocket as the upper shaft is displaced past the catch pocket to arrest axial movement of the upper shaft in the first direction thereby indicating the largest of the top surface angles that is less than the downhole tool's inclination angle. 24. The method of claim 23, wherein the knob is adapted to pass by a consecutive passage restriction for each corresponding disc that passes by the catch disc such that a pressure pulse is generated corresponding to each passage restriction through which the knob passes. 25. A downhole tool for measuring and communicating inclination of a portion of a drill string relative to the direction of the Earth's gravity vector comprising: an upper end of the tool capable of being attached to a portion of the drill string, a lower end of the tool capable of being attached to another portion of the drill string, and a housing located between and connected to the upper end of the tool and the lower end of the tool;a plurality of discs located within the housing, each disc having an upper surface and being operably connected to a shaft axially located within the housing, the plurality of discs comprising a stack of operably-connected discs, wherein at least some discs in the stack have an upper surface angled at a known angle with respect to the axis of the shaft and wherein the upper surface of each disc which has a disc below it defines a larger positive angle with respect to the shaft than the angle of the upper surface of the lower disc with respect to the shaft, to provide a stack of upper surfaces with known and upwardly-progressively larger angles relative to the shaft;the lower disc surface of each disc which has a disc below it and the upper surface of the disc below the upper disc comprise a ball space capable of holding and moving balls with the housing, the plurality of discs defining at least a first ball space and a second ball space, the first ball space being below the second ball space;one or more first balls located within the first ball space and laterally moveable upon the first upper surface of the first ball space;one or more second balls located within the second ball space and laterally movable upon the second upper surface of the second ball space;a flow conduit within the housing capable of permitting a flow of fluid therethrough;a knob located within the housing having an upper surface area and operably connected to the shaft, the knob and shaft movable axially within the flow conduit;a biasing mechanism located within the housing and adapted to bias the shaft in the first direction;the combination of the biasing mechanism's biasing force and the size and shape of the knob's upper surface area being adapted to both enable a sufficient flow of fluid within the flow conduit in the second direction to exceed the biasing force to move the knob and shaft in the second direction, and to enable a lesser flow of fluid within the flow conduit to cause the knob and shaft to move in the first direction;a catch pocket located on an inner surface of the housing, the catch pocket having an upper surface capable of engaging one or more balls which are moving in a first axial direction and which move laterally into the catch pocket to stop the balls from further movement in the first direction and having a sloping lower surface capable of releasing one or more balls which are engaged in the catch pocket to move out of the catch pocket in a second axial direction;the catch pocket, the first ball space, the first upper surface, and the first ball combination being capable of responding to the downhole tool being inclined at an angle greater than the first upper surface, and the biasing mechanism moving the shaft in the first direction by the first ball moving from a non-engaged position where the first ball is not engaged with the catch pocket to arrest the shaft from further movement in a first direction, to an engaged position where the first ball engages the catch pocket to arrest the shaft from further movement in the first direction;the catch pocket, the first ball space, the first disc surface, and the first ball combination being capable of responding to movement of the shaft in the second direction by allowing the first ball, if engaged in the catch pocket, to disengage from the catch pocket in the second direction to allow further movement of the shaft in the second direction;the catch pocket, the second ball space, the second disc surface, and the second ball combination being capable of responding to the downhole tool being inclined at an angle greater than the second upper surface, and the biasing mechanism moving the shaft in the first direction by the second ball moving from a non-engaged position where the second ball is not engaged with the catch pocket to arrest the shaft from further movement in a first direction, to an engaged position where the second ball engages the catch pocket to arrest the shaft from further movement in the first direction;the catch pocket, the second ball space, the second disc surface, and the second ball combination being capable of responding to movement of the shaft in the second direction by allowing the second ball, if engaged in the catch pocket, to disengage from the catch pocket in the second direction to allow further movement of the shaft in the second direction;a plurality of passage restrictions within the flow conduit; the knob movable axially within the flow conduit and movable to be adjacent at least some of the passage restrictions so the knob interacts with the passage restrictions and the fluid to cause measurably different pulses within the fluid when the knob is moved relative to the passage restrictions;wherein movement of the knob relative to the passage restrictions corresponds to movement of the shaft before further movement of the shaft is arrested by the first ball being engaged by the catch pocket and creates a pressure pulse in the fluid which corresponds to the first ball being engaged by the catch pocket;the tool being capable of measuring the drill string's inclination at the point where the tool is located, the measurement being within an upper and lower range of inclinations, the lower range inclination corresponding to the first upper surface, which has the largest upper surface angle of the tool's stack of upper surface angles which is less than the tool's angle relative to the Earth's gravity vector, and the upper range inclination corresponding to the second upper surface, which has the smallest upper surface angle that is larger than the tool's angle relative to the Earth's gravity vector, and the tool being capable of communicating the measured range of upper and lower inclinations by one or more pressure pulses which identify that the first ball on the first upper surface has been engaged by the catch pocket. 26. A downhole tool for measuring and communicating inclination of a portion of a drill string comprising: a housing having a flow conduit therein for a flow of drilling fluid therethrough, the flow conduit having a plurality of passage restrictions therein, wherein the housing is made of stainless steel;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 directly adjacent one of the passage restrictions;a spring adapted to bias the knob in a first direction;wherein the knob is movable 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;one or more discs operably connected to the upper shaft, wherein a top surface of each disc is angled at a known angle with respect to the upper shaft and the inclination of the discs is successively increased such that the disc closest to the upper shaft has the highest inclination of all the discs, wherein the discs are made of a titanium, carbide and stainless steel alloy;one or more balls disposed on the discs, wherein the at least one ball is made of carbide;wherein the one or more balls is rollable into a catch pocket adapted to engage the one or more balls and arrest the upper shaft from any further axial movement in the first direction upon sufficient inclination of the upper shaft;wherein the knob communicates the angle of the disc having the highest inclination and bearing the one or more balls that is engaged with the catch pocket to a pressure pulse signaling system;a housing having a flow conduit therein for a flow of drilling fluid therethrough, the flow conduit having at least four passage restrictions therein;a knob located within the housing, the knob being movable axially within the flow conduit wherein the knob is adapted to interact with the passage restrictions to cause a flow restriction within the flow conduit when the knob is adjacent one of the passage restrictions relative to when the knob is not adjacent one of the passage restrictions;a biasing mechanism adapted to bias the knob in a first direction, wherein the knob is operably connected to a upper shaft and the biasing mechanism is a spring adapted to operably engage the upper shaft and the housing;wherein the knob is movable upon the influence of the flow of drilling fluid in a second direction wherein the second direction is opposite the first direction and the knob includes a surface area which is large enough that the flow of drilling fluid is capable of displacing the knob in the second direction; anda dampening mechanism adapted to dampen movement of the upper shaft in at least one axial direction. 27. A downhole tool for measuring and communication inclination of a portion of a drill string relative to a gravity vector of a borehole comprising: a housing having an axial flow conduit therein for a flow of drilling fluid therethrough, the housing having a bottom;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 directly adjacent one of the passage restrictions, wherein the knob is operably connected to an upper shaft;a biasing mechanism adapted to bias the knob in a first direction opposite the bottom of the borehole;wherein the knob is movable upon the influence of the flow of drilling fluid in a second direction wherein the second direction is opposite the first direction;a stack of discs arranged axially along the upper shaft, the discs having an angled top surface, the angled top surface of each of the discs inclined with respect to the axis of the upper shaft, at successively decreasing angles towards the bottom of the housing;balls rollable on the angled top surfaces of the discs; anda catch pocket, wherein a ball within the catch pocket is capable of stopping movement of the shaft in the second direction, making the downhole tool capable of communicating the largest top surface angle of the discs that is less than the downhole tool's inclination angle.