SHAPED SPRING MANUFACTURING METHOD Russian patent published in 1994 - IPC

FIELD: working of metal. SUBSTANCE: method involves winding predetermined quantity of circular or rectilinear coils, one coil closely to the other, on preliminarily made mandrel of required shape; locating mandrel with wound coils into die-casing with inner opening, which may have various shapes, and subjecting it to multiple-staged plastic deformation, with delay between stages being provided. Amount of reduction at primary stage does not exceed 25-30% of total deformation required for complete winding of wire between mandrel and die-casing. Then spring spreading and thermal treatment are conducted. Spring spreading is effectuated by uniform stretching or by means of bodies of rotation, for example, by disks. EFFECT: high quality of springs. 4 cl, 25 dwg, 1 tbl