Heat insulating sheet or panel

Claim 1

A HEAT INSULATING PANEL COMPRISING, A PAIR OF BRIGHT METALLIC FOIL, HEAT REFLECTING SHEETS EACH HAVING INNER AND OUTER HEAT-REFLECTING SURFACES AND EACH HAVING A PLURALITY OF SIMILAR SHARP ANGLE CORRUGATIONS WHICH EXTEND IN THE DIRECTION OF THEIR RIDGE LINES NORMAL TO A PLANE PASSING THROUGH BOTH SHEETS AND WHICH FOLLOW ON EACH OTHER IN JUXTAPOSED RELATION IN SAID PLANE TO RENDER THE CROSSSECTIONS OF SAID SHEETS IN SAID PLANE OF THE SAME SAWTOOTH SHAPE, SAID SHEET BEING MUTUALLY SEPARATED WITH RESPECTIVE CORRUGATIONS THEREOF REGISTERING ANGLE FOR ANGLE AND WITH CORRESPONDING THEREOF REGISTERING CORRUGATIONS BEING PARALLEL TO THEREBY DEFINE BETWEEN SAID SHEETS AN INTERSPACE HAVING IN SAID PLANE A CROSS-SECTION OF SAWTOOTH SHAPE AND OF AN INTER-SHEET WIDTH LESS THAN THE DIMENSION IN SAID PLANE OF THE FACE OF ONE OF SAID CORRUGATIONS, AND A LAYER OF FIBROUS GLASS WOOL OCCUPYING SUBSTANTIALLY ALL OF SAID SAWTOOTH-SHAPED INTERSPACE TO THE EXCLUSION OF AIR POCKETS THEREIN, SAID GLASS WOOL LAYER AND SAID SHEETS BEING BONDED TOGETHER TO FORM A UNITED PANEL STRUCTURE.