GB1294622A - Dual chambered tires - Google Patents

Abstract

1294622 Pneumatic tyres GENERAL TIRE & RUBBER CO 17 May 1971 [27 May 1970] 15202/71 Heading B7C A single dual chambered tyre comprises an outer tyre member 20, having a toroidal carcass reinforced by spaced radial plies 24, 16 of substantially parallel cords, which cords intersect the mid-circumferential plane P at 90 degrees, and an inner tyre member 30 having a toroidal carcass spaced radially inwardly from said outer tyre member, and reinforced by an even number of spaced cross-plies 34, 36 each of parallel cords disposed to intersect the mid-circumferential plane at an acute angle. The cords of the adjacent cross-plies 34, 36 are indexed at substantially equal but opposite angles to the mid-circumferential plane, wherein said acute angle is between 25 and 45 degrees. The inner and outer tyre members are joined together around the bead portions 12. A valve member 11 extends through one of the sidewalls 16 of the outer tyre member and into the outer chamber 25. Chafer strips are incorporated in the region of the plies 24, 26 receiving valve 11 to reinforce the radial ply 24. The dual chambered tyre may be manufactured by placing component parts of the inner tyre member on a cylindrical drum 40, covering said inner tyre member except for the annular marginal edges thereof with an adhesion preventing substance, and placing all components except the belt 15 and tread 14 of the outer tyre components on top of the inner tyre components. Circular inextensible bead rings 13 are disposed at the ends of the drum against the marginal layer of the assembly. The marginal edges are turned over said bead rings to tie-in the carcasses to the bead. The sidewalls 16 are secured to the outer tyre member, and the outer tyre member is inflated to separate adjacent parts of inner and outer tyre members. The whole tyre assembly, so far described, is then expanded to have toroidal form so that the outer member may engage the belt 15 and tread 14. The uncured tyre is then cured in a mold employing the outer chamber, which is lined with strong liner material capable of withstanding high temperatures of curing media such as steam, as a curing bladder for shaping the inner tyre member 30. The different expansion characteristics of the outer radial carcass and inner cross-ply carcass cause a dual chambered tyre 10 to be formed by the method hereinbefore described. The cords 18, 28, 38 may be manufactured from rayon, nylon, polyester, glass, steel or a mixture thereof, and the adhesion preventing material from zinc stearate, non-adhering butyl current, talc, paper or Holland cloth.