GEAR FOR DETERMINATION OF DIRECTION OF BOREHOLE DRILLING Russian patent published in 1994 - IPC

FIELD: borehole drilling. SUBSTANCE: gear for determination of direction of borehole drilling has deflection scale in the form of semicircle, plumb bob, tubular guide and source of light and focusing element placed uniaxially in it for movement along its axis, horizontal dial with uniform circular scale, case with sector slot-shaped hole and pointer-angle indicator. Case with sector slot-shaped hole is anchored in center of dial for turning about vertical axis. Pointer-angle indicator is fixed immobile. Tubular guide is mounted for sector movement in vertical plane with respect to case. EFFECT: increased accuracy of determination of direction of drilling. 6 dwg, 1 tbl