Pneumatic tire with cap ply comprising weft inserted warp knit fabric

Abstract

A pneumatic tire (100) has a tread, a carcass (200) with belt plies (230) disposed below the tread (500), and a cap ply layer (300) between the tread and the belt plies of the carcass. The cap ply (300) is a weft inserted warp knit fabric tape (310) comprising an in-lay warp yarn set (312), a weft inserted yarn set (313), and a stitching yarn set (311), wherein the stitching yarn set forms a repeating stitch pattern on each warp yarn comprising a sequence of at least 2 stitches around the warp yarn from one stitching yarn and at least 2 stitches around the warp yarn from the adjacent stitching yarn. The tape (310) is wound in a flat helically wound around the belt plies (230) and covered with a tread (500) of the tire.

Description

technical field [0001] The present invention relates generally to pneumatic tires and in particular to the construction of ply tires having belt layers. Background technique [0002] Typically, tires are made of a single or multiple carcass with generally U-shaped segments of metal beads on the inner periphery of the walls. The tire carcass is supported by layers of steel cords that surround the outer surface of the carcass and extend across the width of the tread. Such a steel belt layer is relatively inextensible in the intended direction of rotation of the tyre, the steel belt layer comprising steel belt wires arranged in parallel or at a small angle relative to the direction of rotation. The belt ply acts to limit the movement of the tread giving the tire better road grip characteristics. Supports of this type are particularly important in radial tires, where the carcass is constructed of rubberized fabric with a transverse extension, that is, from bead to bead diamete...

AI Technical Summary

Problems solved by technology

However, the warp yarns of the Sowa patent cannot be kept exactly parallel and equally spaced because the weft yarns "are placed roughly over the warp yarns at an almost perpendicular angle over the warp yarns without weaving and braiding a binder yarn of fine fibers around the warp and weft yarns" (claim 2 , lines 3-6)

Thin fibers do not hold adjacent warp yarns together sufficiently to keep warp yarns parallel and properly spaced, and can cause yarn displacement if cut

Binder yarn 22 in Figure 3 joins adjacent warp yarns, but is too loose to maintain a constant spacing between warp yarns

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