公开(公告)号：JPH02114007A

公开(公告)日：1990-04-26

申请号：JP26622688

申请日：1988-10-24

Applicant: BRIDGESTONE CORP

Inventor： TANAKA MAKOTO

IPC: B60C9/18 ,  B60C9/08 ,  B60C11/01 ,  B60C11/04 ,  B60C11/12

Abstract: PURPOSE:To prevent the occurrence of cracking on the shoulder rib surface, i.e., sipe tear, by extending sipes completed in shoulder ribs at one end on the same side as the extension direction of cords of the outermost layer belt against the extension direction of a tire equator line. CONSTITUTION:A radial tire for a heavy load has a carcass 1 constituted of one or more layers of carcass plies made of cords extended in the radial direction and three belt layers 4-6, for example, arranged on the outside in the radial direction. Ribs 8 and 9 partitioned by four main grooves 7 and extended in the tire peripheral direction are provided on the peripheral face of a tread section 3, and multiple sipes 10 are provided only on the shoulder rib 8 in the tire peripheral direction. The sipes 10 are blind sipes completed in the shoulder rib 8 at both ends, and the sipes 10 are extended in the same direction as the extension direction of cords 11 of the outermost belt layer 4 against the extension direction of a tire equator line X over the whole length.