摘要 |
Improved apparatus for measuring the angular deviation from the vertical of the end of the drill string which includes a housing adapted for insertion in the drill string, a pendulum pivotally mounted in the housing and capable of swinging through large angles, and a substantially perfectly balanced catch link pivoted at the same point as the pendulum and normally coaxially aligned with the end of the drill string. Means are provided for coupling the pendulum and catch link together at a preselected angle and for measuring the deflection of the coupled pendulum and catch link from the axis of the end of the drill string so that the angular deviation from the vertical of the end of the drill string may be determined. Means are provided for signalling the measure of the deflection to the surface.
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