Insulating structure for high voltage power cables

Claim 1

A STRUCTURE CAPABLE OF BEING CHARGED WITH GAS UNDER SUPERATMOSPHERIC PRESSURE AND, HAVING BEEN SO CHARGED, OF OPERATING AS A SHEATHLESS GAS-FILLED HIGH VOLTAGE POWER CABLE, THE STRUCTURE COMPRISING AT LEAST ONE CONDUCTOR HAVING A FLEXIBLE EFFECTIVE SURFACE FO A SMOOTH, NON-REENTRANT FORM, A DIELECTRIC WALL BUILT UP ON SAID CONDUCTOR AND CONSISTING ESSENTIALLY OF LAYERS OF HELICAL LAPPINGS OF TAPES OF PLASTICS FILM, AND SURROUNDING THE WALL AT LEAST ONE LAYER OF HELICALLY APPLIED METAL TAPE CAPABLE OF REINFORCING THE WALL AGAINST THE INTERNAL PRESSURE EXERTED UPON IT WHEN THE STRUCTURE IS CHARGED WITH GAS TO RENDER THE STRUCTURE OPERATIONAL AS A GAS-FIELD HIGH VOLTAGE CABLE, NARROWER TAPES OF PLASTICS FILM BIENG USED IN THE REGION OF THE DIELECTRIC WALL ADJACENT THE CONDUCTOR AND SUCCESSIVE TURNS OF THE TAPES OF EACHLAYER OF THE INNER PART OF THE WALL OVERLAPPING EACH OTHER AND SUCCESSIVE TURNS OF THE TAPES OF EACH LAYER OF THE OUTER PART OF THE WALL BEING SEPARATED BY A SAP, WHEREBY THE GAS SPACES IN THE WALL ARE OF A PREDETERMINED SHAPE AND DIMENSIONS SUCH THAT IONIZATION OF GAS IN SAID SPACES IS INHIBITED AND THEIR TOTAL VOLUME IS SUCH THAT AT THE NORMAL OPERATING TEMPERATURE AND PRESSURE OF THE CABLE THEY ACCOMMODATE THE THERMAL EXPANSION OF THE SOLID DIELECTRIC MATERIAL OF THE WALL.