GB827633A - Improvements relating to pneumatic vehicle wheel tyres - Google Patents

Abstract

827,633. Pneumatic tyres. PIRELLI S.p.A. Oct. 8, 1957 [Dec. 22, 1956], No. 31449/57. Class 144 (2). A flexible, tension-resistant ring-shaped cineture extending circumferentially around a pneumatic tyre carcase below the tread, is comprised of a bias-cut strip of parallel-cord fabric which is folded upon itself lengthwise of the strip so that there are at least two fold lines in the cincture extending parallel to, and either adjacent or at positions on each side of, the mid-circumferential line, the free edges of the strip being disposed at or near the lateral edges of the cincture and the cored angles in adjacent folds being opposite and within the range 5 to 45 degrees. The cincture may comprise two folded strips 3, 4 disposed side by side, Fig. 4, to provide a single layer of full cincture width, the respective fold lines being adjacent each other at the mid-circumferential line. To reinforce the continuity break, a strip 5 folded as shown may be disposed above or below the break. Fig. 5 shows a single layer cincture comprising two folded strips 3, 4 disposed in overlapping relation with the overlap, as with the strip 5 of Fig. 4, extending for at least a quarter of the full cincture width, and straddling the mid-circumferential line. Fig. 6 shows a two layer cincture, each layer comprising two folded strips 3, 4 or 3<SP>1</SP>, 4<SP>1</SP> disposed side by side, the adjacent folds in the two layers being symmetrically disposed on opposite sides respectively of the mid-circumferential line. In a further arrangement, two or more layers each arranged as in Fig. 5, may be superposed, the degree of overlap in each layer decreasing from the radially innermost layer to the outermost layer. To obviate local thickenings in the cincture, the arrangements of folded strips may be combined with one or more pairs of conventional breaker strips having a 40 to 45 degree cord angle and disposed in crossed relation above and/or below the folded strips. The folded strips may comprise rubberized cords of natural or synthetic textile, or metallic material. Specifications 700,435, 769,325, 808,548 815,053 and 818,729 are referred to.