METHOD FOR MAKING COIL SPRINGS Russian patent published in 1999 - IPC

FIELD: plastic metal deforming for making from round blank coils with non-round cross section of turns designed for manufacturing springs, rings and so on. SUBSTANCE: rotating rolls have shaped grooves, for example rectangular -shaped ones, and they are arranged with inclination relative to fed blank wound onto mandrel arranged between said rolls. Blank is fed to working zone between -shaped roll grooves and cylindrical surface of mandrel placed between rolls with minimum possible gap. Wire circle is clamped by means of inlet cone of rolls. In deformation zone wire circle is deformed to rectangular or other shape depending upon profile of roll grooves. Formed coil after shaping zone is subjected to deformation in next stages, namely: its turns are spaced by predetermined pitch; then coil is cut by measured-length blanks from which after end working, heat treatment, training and other procedures springs are made. In apparatus for performing the method all members are arranged coaxially and grooved rolls embrace them. Compression springs with rectangular profile of turn cross section made by such method have working capacity at least four times higher than wire springs with round profile of their turns not-subjected to plastic deforming. EFFECT: enhanced working capacity of springs. 2 dwg