METHOD FOR PRODUCTION OF MULTI-CORED HELICAL SPRINGS Russian patent published in 2009 - IPC B21F35/00 

FIELD: technological processes.

SUBSTANCE: method includes cable twisting and its coiling onto holder with simultaneous kinking and stretching of wire at the same operation, cutting of spring with specified length, welding of cores, thermal treatment, measurement of geometric and power parameters and application of protective coating. In order to achieve springs resistance and reduce deviations in height, after thermal treatment spring is pressed by axial load that exceeds F₃ within the limits up to 300F₃, where F₃ is spring force at maximum deformation. If required, repeated pressing is done by load increased proportionally to ratio of required yield to yield from application of the first load. At that loads may be vibrational.

EFFECT: higher dynamic strength, with accurate and time-stable elastic properties in process of their operation with contact of turns.

3 cl