METHOD OF FABRICATING CURVED ITEMS FROM BAR Russian patent published in 2009 - IPC B21D7/06 B21D22/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to metal pressure working technologies and is intended for implementation in metallurgy. Primarily one performs mandrel bending of two loops on the blank end sections by way of having the bar rolled with rollers moving along curvilinear trajectories. Subsequently the blank is bent in the same direction to produce a third loop. Two blanks in two positions are bent simultaneously. In the first and the second positions accordingly the two primary loops and the third loops are produced. During the interval between two successive bending operations the blank with two loops becomes shifted from Position 1 to Position 2 along the mandrels which process is accompanied by simultaneous relocation of the finished item.

EFFECT: provision for high endurance of stamp.

5 cl, 6 dwg, 1 ex