Patent ID: 11964321
Assignee: NHK SPRING CO., LTD.
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 7:
8. A method of manufacturing a coil spring, comprising:
moving a wire toward a wire guide by feed rollers;
forming the wire coming out of the wire guide into a helical shape which includes an arc portion by a first forming roller, a second forming roller and a pitch tool;
stopping the moving of the wire when one coil spring of a predetermined length is formed;
supporting the arc portion in a radial direction of the wire by a support mechanism which includes a clamping tool and the pitch tool;
moving a cutting rotor in the radial direction of the wire from a standby position toward the wire;
cutting the wire in the radial direction of the wire between the second forming roller and the pitch tool by the rotating cutting rotor;
moving the second forming roller in a direction away from the cutting rotor such that a cut surface of the wire is separated from the cutting rotor due to elasticity of the wire; and
moving back the cutting rotor toward the standby position.