Inner tube for pneumatic tires and method of making

Claim 1

AN INNER TUBE FOR PNEUMATIC TIRES COMPRISING AN ENDLESS INNER TUBULAR LAYER OF A COMPOUND OF A RUBBERY COPOLYMER OF ISOBUTYLENE AND A DIOLEFINIC COMPOUND WHICH COPOLYMER CONTAINS ISOBUTYLENE IN PREPONDERANCE AND AN ENDLESS OUTER TUBULAR LAYER OF A RUBBERY POLYMER OF A VULCANIZED, COMPOUNDED, CONJUGATED DIOLEFINIC COMPOUND OF LESS THAN SEVEN CARBON ATOMS, AND A CONDUIT FOR CONTROLLABLY SUPPLYING INFLATION LIQUID TO THE CAVITY OF SAID INNER TUBULAR LAYER, THE ENTIRE INNER SURFACE OF SAID OUTER TUBULAR LAYER BEARING AGAINST AND BEING DIRECTLY BONDED BY VULCANIZABLE OF SAID OUTER LAYER TO THE OUTER SURFACE OF SAID INNER LAYER, BOTH THE OUTER AND THE INNER LAYER OF SAID TUBE BEING AT THE SAME TIME IN A NATURAL UNSTRESSED AND MOLDED STATE, SAID OUTER LAYER HAVING THE FLOW CHARACTERISTICS OF A RUBBER LAYER THAT HAS BEEN VULCANIZED IN CONTACT WITH A PREVULCANIZED INNER LAYER IN CONTACT WITH A RIGID, ANNULAR FORMING SURFACE.

Claim 3

A METHOD OF MAKING TUBES FOR RETAINING AIR IN PNEUMATIC TIRES WHICH COMPRISES FLATTENING PORTIONS OF AN ENDLESS FLUID-RETAINING BASE TUBE, WHICH IS FORMED PRINCIPALLY OF A VULCANIZED COMPOUNDED COPOLYMER OF ISOBUTYLENE AND A DIOLEFINIC COMPOUND COPOLYMERIZABLE THEREWITH, APPLYING AGAINST THE ENTIRE FLATTENED OUTER SURFACE OF SAID BASE TUBE A LAYER OF A VULCANIZABLE RUBBER COMPOUND TO FORM A COMPOSITE TUBE BLANK HAVING AN OUTER CONTINUOUS WALL FORMED OF AN INNER ENDLESS TUBULAR LAYER OF SAID VULCANIZED COMPOUNDED COPOLYMER AND AN OUTER ENDLESS LAYER OF SAID VULCANIZABLE RUBBER COMPOUND, AND BONDING THE SAID INNER AND OUTER LAYERS DIRECTLY TOGETHER OVER THEIR ENTIRE CONTACTING AREAS BY CURING THE COMPOSITE TUBE BLANK IN AN ANNULAR MOLD UNDER PRESSURE APPLIED TO THE CAVITY OF SAID BASE TUBE.

Claim 4

A METHOD OF MAKING TUBES FOR RETAINING AIR IN PNEUMATIC TIRES WHICH COMPRISES FLATTENING PORTIONS OF AN ENDLESS FLUID-RETAINING BASE TUBE, WHICH IS FORMED PRINCIPALLY OF A VULCANIZED COMPOUNDED COPOLYMER OF ISOBUTYLENE AND A DIOLEFINIC COMPOUND COPOLYMERIZABLE THEREWITH, APPLYING AGAINST THE ENTIRE FLATTENED OUTER SURFACE OF SAID BASE TUBE A LAYER OF A VULCANIZABLE RUBBER COMPOUND TO FORM A COMPOSITE TUBE BLANK HAVING AN OUTER CONTINUOUS WALL FORMED OF AN INNER ENDLESS TUBULAR LAYER OF SAID VULCANIZED COMPOUNDED COPOLYMER AND AN OUTER ENDLESS LAYER OF SAID VULCANIZABLE RUBBER COMPOUND, AND BONDING THE SAID INNER AND OUTER LAYERS DIRECTLY TOGETHER OVER THEIR ENTIRE CONTACTING AREAS BY CURING THE COMPOSITE TUBE BLANK IN AN ANNULAR MOLD UNDER PRESSURE APPLIED TO THE CAVITY OF SAID BASE TUBE.