METHOD FOR WORKING CONE THREADS OF TUBE COUPLINGS Russian patent published in 2003 - IPC

FIELD: tube making industry branches, manufacture of couplings of casing, pump-compressor, oil and gas pipelines having at both sides similar-dimension threads. SUBSTANCE: method comprises steps of working during one stage both threads of coupling blank by means of tool mounted in boring bar; moving boring bar along axis parallel relative to thread slope; mutually turning cutting surfaces of tool by angle equal to 180 degrees; in order to enhance accuracy and efficiency and to enlarge manufacturing possibilities, limiting length of tube coupling by allowance range not exceeding at least half of axial allowance range for position of measuring plane of thread gage relative to end face of coupling at testing thread by means of said thread gage; moving boring bar along axis passing through geometry center of coupling; working both threads by means of pairs of tools mutually shifted along axis and radially spaced from it; changing from pass to pass radial spacing of tools due to shifting tools relative to boring bar. EFFECT: enhanced accuracy and efficiency of working, enlarged manufacturing possibilities of method. 3 cl, 1 dwg