THERMO-INSULATED FOOTWEAR

1299353 Boots &c S GULYAS 6 May 1970 [6 Feb 1969] 6522/69 Heading A3B A thermally insulated boot or shoe includes an outer part consisting of a sole 1 and an upper 2, and an inner lining 3 of flexible material defining a cavity between the outer part 1, 2 and the inner lining 3, the cavity extending over the whole of the inner surface of the outer part 1, 2 and being filled with a soft heat insulating material 5 having thicker portions in the region of the instep and heel to provide a clamping effect to prevent excessive movement relative to the wearer's foot. The sole I and upper 2 may be natural or synthetic rubber, e.g. styrene butadiene rubber, or other plastics material, e.g. polyvinyl chloride, and may be formed integrally by moulding, e.g. by dips-, slush- or rotational moulding techniques. The lining 3 may be a nylon fabric and is attached to the outer at 4 by welding, adhesive, heat-sealing or other bonding technique. The insulating layer 5 may be a polyurethane foam and a layer of the foam may be bonded to the nylon fabric before it is made up into the lining shape. Alternatively the layer 5 may be foamed in situ.