METHOD OF ROLLING OUTER TRAPEZOIDAL THREAD Russian patent published in 2012 - IPC B21H3/04 B24B39/04 

FIELD: process engineering.

SUBSTANCE: invention relates to machine building, particularly, to trapezoidal thread rolling. Threading rollers are revolved while billet is translated at pitch equal to that cut thread. Threading rollers have outer peripheral working surface consisting of conical intake part with threads and cylindrical gauging part. Fillets that feature the shape of the cone side surface section are made on intake conical threads. Depth of said fillets in lengthwise direction extend over entire width of thread profile crest while depth of said fillets in radial direction extend over entire lateral side of thread profile. Length of said fillets does not exceed thread pitch. Distance between fillets in thread direction does not exceed thread pitch. Said filets are arranged staggered. Fillets on one side of thread profile alternate with those on opposite side.

EFFECT: higher efficiency of threading, ruling out slippage of workpiece relative to rollers.

7 dwg