Patent ID: 7392857
Filing Date: 2008-07-01
Classification: E21B,Y10T

Abstract:
1. A drill bit, comprising: an axis of rotation and a drill bit body intermediate a threaded end and a working face; the drill bit body comprising a fluid passageway comprising a first seat and housing a jack element substantially coaxial with the axis of rotation; a stop element disposed within the passageway comprising a first near-sealing surface; the jack element comprising a shaft intermediate an indenting end and a valve portion, the indenting end extending through the working face; the valve portion comprising a second near-sealing surface disposed adjacent the first near-sealing surface and a second seat disposed adjacent the first seat; wherein as the formation being drilled strongly resists the jack element, the distance between the respective sealing surfaces narrows causing an increase in fluid pressure within the passageway and forcing the indenting end down into formation, which movement of the jack relieves the pressure build such that the formation pushes the jack element back thereby oscillating the jack element.