Patent ID: 8182634

Claim:
A belt member producing method comprising forming a separated strip piece of a predetermined width W by cutting a strip material comprising a plurality of reinforcement cords, the strip material having been fed from a strip roll, to a regular size while the strip material is on a regular-length feeding conveyor, the regular-length feeding conveyor and the strip roll feeding the strip material being in the same central axial line, maintaining the separated strip piece after the cutting occurs on the regular-length feeding conveyor temporarily, then conveying the separated strip piece vertically to a transfer conveyor by a conveying device, so as to convey the separated strip piece from the regular-length feeding conveyor to the transfer conveyor, in the traveling direction of the regular-length feeding conveyor and the transfer conveyor, the transfer conveyor being arranged substantially parallel to the regular-length feeding conveyor, while rotating the separated strip piece through a predetermined angle in such a manner that cut sides of the separated strip piece are in parallel with a traveling direction of the transfer conveyor and overlapping continuously an integral number N int of separated strip pieces on each other on the transfer conveyor in such a manner that the separated strip pieces are overlapped on each other by an overlapping amount P along non-cut sides thereof, so as to produce a belt member having a desired length equal to a predetermined length L of a belt layer of a pneumatic radial tire, the belt member producing method further comprising determining the integral number N int and the overlapping amount P by the following steps of: (1) selecting a desired cutting angle θ pre relative to a traveling direction of the strip material when the strip material is cut to the regular size; (2) calculating a number N cal of separated strip pieces necessary for forming a belt member by the following equation, N cal =(L/W)×sin θpre (3) rounding up the number Ncal of separated strip pieces so calculated to obtain an integral number N int , and (4) calculating an overlapping amount P of the separated strip pieces by the following equation, P=W−L ×sin θpre /N int .