Patent ID: 8850862

Claim:
A method of rolling a substantially planar electric wire, which is for use in forming a stator coil of a stator of an electric rotating machine, by more than one turn into a spiral shape, wherein the stator comprises a hollow cylindrical stator core having a plurality of slots that are formed in a radially inner surface of the stator core and spaced in a circumferential direction of the stator core, and the planar electric wire includes a plurality of in-slot portions, each of which is to be received in a corresponding one of the slots of the stator core, and a plurality of turn portions each of which connects an adjacent pair of the in-slot portions and is to be located outside the slots of the stator core, the method comprising the steps of: preparing a radially inner pressing member having an outer surface, a radially intermediate pressing member having radially inner and outer surfaces, and a radially outer pressing member having an inner surface; pressing a first part of the electric wire between the outer surface of the inner pressing member and the inner surface of the intermediate pressing member, thereby plastically deforming the first part to extend along the outer surface of the inner pressing member; and pressing a second part of the electric wire between the outer surface of the intermediate pressing member and the inner surface of the outer pressing member, thereby plastically deforming the second part to extend along the outer surface of the intermediate pressing member.