DEVICE FOR CUTTING THREAD ON PIPES AT WELL HEAD Russian patent published in 1999 - IPC

FIELD: oil and gas production industry. SUBSTANCE: device is intended for cutting taper thread on pipes used in oil industry at well head and in geological prospecting operations. Device is made up of rotation mechanism with power drive unit and cutter holder. Device is provided with table, mechanism for converting rotatory motion from power drive unit into rotatory advancing motion of tool along generant of casing string. Converting mechanism includes gear wheel, two gears and screw which is fastened with table. Screw is moving along bands of centering housing. Also provided is follower which is made in the form of inclined upright fastened on gear wheel and slides located on table and adapted for moving over prismatic guide members. Also there is mechanism for withdrawing cutter from cutting zone at end of mechanism stroke. This mechanism has stop fastened on inclined upright with local recess. Centering mechanism is made up of housing retainer blocks movably connected to housing. Retainer blocks are provided with inserts allowing for cutting thread on pipes of various diameters. Power drive unit is represented by hydraulic motors. EFFECT: higher efficiency. 7 dwg