Patent ID: 8080120

Claim:
A method of manufacturing an annular concentric stranded bead cord, comprising: repeating winding movements as a result of, while rotating an annular core in a peripheral direction, traversing and reciprocating a reel, upon which a lateral wire is wound, with respect to a surface of the annular core to inner and outer sides of a ring of the annular core, to traverse the reel so that a winding deviation angle β S of the lateral wire with respect to the surface of the annular core does not exceed 29 degrees, whereby the lateral wire, drawn out from the reel, is continuingly wound upon the annular core to form one or a plurality of sheath layers, wherein an in-plane movement of the reel with respect to the surface of the annular core is pendulum swinging movement by swinging an arm which supports the reel, wherein, when the lateral wire, drawn out from the reel, is continuingly spirally wound upon the annular core by repeatedly traversing the reel with respect to the surface of the annular core to the inner and outer sides of the ring of the annular core as a result of moving the reel to a position where the reel traverses the inner side of the ring of the annular core at one end of a pendulum period and to a position where the reel traverses the outer side of the ring of the annular core at the other end of the pendulum period, a position of a fulcrum of the pendulum swinging movement of the reel is set so that an angle between the lateral wire, drawn out from the reel, and a tangential line of a circle of the annular core passing through a winding point where the lateral wire is wound with respect to the annular core is in a range within 15 degrees at a side opposite to the annular core with respect to the tangential line, and is in a range within 55 degrees at the side of the annular core with respect to the tangential line, wherein a coil diameter of the lateral wire, taken up by the reel, is previously reformed so as to satisfy either one of the following expressions: 0.90D R ≦D SO ≦3.3D R , or 0.55D C ≦D SO ≦2.0D C, where D R is an outside diameter of the reel, D SO is the reformed coil diameter of the lateral wire, and D C is a center diameter of the annular core.