GB568843A - Antiskid pneumatic tire and method of making same - Google Patents

Abstract

568,843. Wheel tyres, pneumatic. WINGFOOT CORPORATION. Nov. 4, 1943, No. 18337. Convention date, June 12, 1943. [Classes 144 (i) and 144 (ii)] [Also in Group V] A pneumatic tyre comprises a resilient tread with short helical springs embedded therein, with their cylindrical sides substantially flush with or slightly protruding beyond the tread surface. The rows of springs 14, Fig. 18, may be circumferential, transverse or diagonal and are sewn to a green tyre comprising a fabric-ply carcass 26 having an outer rubber layer 27. The springs are made of brass-plated steel wire with square ends and are assembled in a hardrubber mould with close-spaced parallel grooves of half-round cross-section. A thin sheet 16, Fig. 16, of green rubber is then placed on the springs and put in a press. The sheet with the attached springs is then reversed in the mould and another thin sheet 20 of green rubber pressed on to form a complete tread section. The sheets 16, 20 may be coated with a layer of rubber cement 30, 32, and the tyre is then vulcanized, the tread being buffed until the springs protrude slightly. In a modification, sheet 20 is covered with a thin layer 38 of non- wear-resisting rubber which rapidly wears off in service to expose the springs. The tread sections are assembled to form a complete tread, or the tread may be made in one length. Spaces may be provided in the mould longitudinally between adjacent or alternate springs and if the tread is patterned, the corresponding springs are pressed into the rubber layer of the original green tyre without losing their round shape.