Method of manufacturing a pneumatic radial tire including forming a belt layer from strip pieces

A method of manufacturing a belt member for a pneumatic radial tire comprising the steps of:

• feeding a strip material including a plurality of reinforcing cords from a standard measure feeding device which is adjustable in feeding angle to a carrier conveyor;
• cutting the strip material to a predetermined size in sequence to form strip pieces having a predetermined width A while alternately moving the strip material and the carrier conveyor intermittently in synchronization with each other;
• transferring the strip pieces onto the carrier conveyor;
• determining an integer number Nint of strip pieces necessary to form a belt member having a desired length equal to a predetermined length L of a belt layer for the tire with the strip pieces having the predetermined width A by:
• selecting a preferred cutting angle θpre for the strip pieces;
• calculating a number Ncal of strip pieces required to form the belt member by applying the following formula:
• Ncal=(L/A)×sin θpre;
• rounding the calculated number Ncal of strip pieces either up or down to an integer number Nint;
• and
• setting an actual cutting angle θa for the integer number Nint of strip pieces by applying the following formula:
• θa=sin−1 (Nint×A/L);
• and
• butting the Nint strip pieces cut at the actual cutting angle θa sequentially against each other along their longitudinal edges to form the belt member having the desired length equal to the predetermined length L of the belt layer for the pneumatic tire.