PNEUMATIC TYRE CASING Russian patent published in 2002 - IPC

FIELD: tyre industry; radial-ply tyres for trucks. SUBSTANCE: pneumatic tyre casing has tread, breaker, side walls, carcass consisting of outer and inner groups of rubberized cord layers, bead rings, fillers and chafer strips. Bead has one bead ring. Number of bead wires in section of ring of from 112 to 144. Two double chafer strips with strength of threads equal to 0.73 - 1.25 of strength of carcass cord threads are arranged between lockups of inner group of carcass layers and inner layer of outer group of carcass layers made of cord threads, strength within 25 and 30 kgf/thread. Ratio of thickness of doubled chafer strips to summary thickness of inner group carcass layers in section passing through base of filler is 0.25-0.40. Chafer strips arranged from inner side of last layer of carcass layer outer group has thickness of 0.65-0.85 of summary thickness of outer group of carcass layers, and strength of cord threads is equal to 2.5-7.5 of strength of carcass cord thread. EFFECT: reduced materials usage, labour input and energy intensity of tyre. 1 tbl, 1 dwg