THREADED SURFACE FORMING METHOD Russian patent published in 1994 - IPC

FIELD: plastic working of metals. SUBSTANCE: method involves moving knurling tool along generatrix surface of article by a succession of longitudinal passes and transverse feed imparted during intervals between longitudinal passes. To effectuated each consecutive pass, knurling tool is installed in the initial position in spaced relation with respect to the initial position of the previous pass in the direction opposite to that of longitudinal pass, with space value being equal to axial elongation of article after previous pass. Knurling tool is moved in the transverse feed direction for a value inversely proportional to the number of longitudinal passes. Longitudinal passes are effectuated with threaded surface pitch value discretely increasing for each subsequent pass by a value equal to axial elongation of pitch after previous pass to nominal pitch value during effectuating terminating longitudinal pass providing forming of threaded surface. EFFECT: increased efficiency and simplified construction. 3 dwg