Coil spring assembly and forming method

摘要

A coil spring assembly, and a method of forming that assembly, in which the assembly's edgemost coil springs are connected to a border wire by a single continuous spiral lacing wire. The method involves the steps of guiding a rotation spiral lacing wire completely around the periphery of a spring coil matrix and border wire through use of helical path defining dies until the leading and trailing ends of the lacing wire are overlapped. During the lacing operation, the helical path defining dies cooperate to deflect a peripheral segment of each corner and edge coil into juxtaposition with the border wire. The resulting final coil spring assembly includes corner coil springs in which the deflected peripheral segments of the corner coils are retained contiguous to the corner of the border wire by the lacing wire.