AUTOMATIC STATIONARY DRILLING TONGS Russian patent published in 2002 - IPC

FIELD: equipment for drilling of oil and gas wells, particularly, automatic stationary drilling tongs applicable in making-and-breaking of thread joints of drill and casing pipes. SUBSTANCE: tongs has body accommodating upper and lower pipe clamping devices, reducing gear, drive motor and torque gage. Tongs is provided with gear box mounted in separate housing. Gear box is located above reducing gear coaxially to reducing gear input shaft. Planetary reducing gear coaxial to low-speed shaft of gear box is located above gear box. Gear box housing is secured to reducing gear housing. Planetary reducing gear housing is turning round its axis in plain bearing. Tongs torque gage has leverage, movable stop of torque adjustment and system of valves for automatic disconnection of drive motor after attainment of preset making torque. Movable stop is installed on cover of planetary reducing gear. All other units of torque gage are immovably located on bracket of reducing gear housing. Upon attainment of preset torque, lever under action of reactive force of movable stop, turns to overcome spring force of lever valve and to open said valve. Pressure through lever valve is supplied to cutoff valve which closes and cuts-off air supply to drive motor. EFFECT: qualitative making-and- breaking of thread joints of drill and casing pipes and accurate adjustment of torque value. 3 cl, 3 dwg