Expansible metal foil package

Claim 1

A CLOSED PACKAGE OF MATERIAL CAPABLE OF EXPANSION WHEN SUBJECTED TO HEAT, THE PACKAGE INCLUDING A PAIR OF TELESCOPED TRAY SECTIONS OF METAL FOIL CAPABLE OF WITHSTANDING THE ELEVATED TEMPERATURES AT WHICH THE MATERIAL WILL EXPAND, EACH TRAY SECTION INCLUDING A BOTTOM WALL, OPPOSITE SIDE WALLS, AND A SINGLE END WALL CONNECTING SAID SIDE WALLS, ONE OF SAID TRAY SECTIONS INCLUDING FLANGES ON ITS SIDE WALLS FOLDED OVER THE SIDE WALLS OF THE OTHER SECTION TO SLIDABLY CONNECT SAID SECTIONS, A COVER OVERLYING SAID TRAY SECTIONS AND COOPERATING WITH SAID SECTIONS TO COMPLETLEY ENCLOSE SAID CONTENTS, SAID SECTIONS INCLUDING COOPERABLE MEANS LIMITING OUTWARD TELESCOPING MOVEMENT OF SAID SECTIONS AND TO PREVENT SEPARATION THEREOF SAID EXPANDABLE MATERIAL SUBSTANTIALLY FILLING SAID SECTIONS, AND BEING IN DIRECT CONTACT WITH ALL OF THE WALLS OF THE TRAY, WHEN THE SECTIONS ARE TELESCOPED INTO FULLY TELESCOPED RELATION, THE VOLUME WITHIN SAID TRAY SECTIONS SUBSTANTIALLY INCREASING WHEN SAID SECTIONS ARE DRAWN APART TO PERMIT EXPANSION OF SAID EXPANDABLE MATERIAL UPON SUBJECTION TO HEAT.