OUTER THREAD OSCILLATION KNURLING METHOD Russian patent published in 2006 - IPC B21H3/04 

FIELD: plastic working of metals, namely formation of outer threads by knurling with use of rollers.

SUBSTANCE: method comprises steps of imparting rotation to knurling rollers and imparting radial feed motion at least to one roller. Each of said rollers includes boss with opening and key groove; central cylindrical, sizing and inlet portions. Cone inlet portions are formed on end part of rollers. Sizing and inlet portions of roller are arranged in periphery and they are shifted in axial direction by angle α to plane normal relative to rotation axis. Length l_s of sizing portion and axial shift angle α ( 0 -45°) are determined respectively according to formulae: l_s = L_th x k_bl/k_r; α = arctg [(L_th - l_s - l_in)D_rol where l_s - length of sizing portion of roller, mm; L_th - length of knurled thread, mm; k_bl -number of thread starts on blank; k_r - number of thread starts on roller; l_in - length of cone inlet portion of roller, mm; D_rol - outer diameter of oscillating rollers, mm.

EFFECT: enlarged manufacturing possibilities, improved efficiency, possibility for forming comparatively large length threads at lowered radial efforts.

5 dwg, 1 ex