Insulated panel having joined connectors

Claim 1

A RECTANGULAR HEAT INSULATING PANEL COMPRISING: A PAIR OF SIDE SHELLS WITH A RELATIVELY THICK LAYER OF HEAT INSULATING MATERIAL THEREBETWEEN, SAID INSULATING MATERIAL HAVING A LOW THERMAL CONDUCTIVITY AND RELATIVELY LOW TENSILE STRENGTH; AT LEAST ONE ELONGATED MEMBER OF RELATIVELY HIGH TENSILE STRENGTH MATERIAL EMBEDDED WITHIN AND SURROUNDED BY SAID INSULATING MATERIAL AND EXTENDING THROUGH THE PANEL SO THAT OPPOSITE ENDS OF SAID MEMBER ARE ADJACENT TWO DIFFERENT EDGES OF SAID RECTANGULAR PANEL; LOCKING MEANS FOR INTERCONNECTING SAID PANEL WITH OTHER INSULATING PANELS, INCLUDING FIRST AND SECOND THIN RECEPTACLES CONNECTED TO THE RESPECTIVE ENDS OF SAID ELONGATED MEMBER, EACH OF SAID RECEPTACLES BEING EMBEDDED IN SAID LAYER OF INSULATING MATERIAL; AN EXTENSIBLE LATCHING DEVICE MOUNTED IN ONE OF SAID RECEPTACLES, A CATCH MOUNTED IN THE OTHER OF SAID RECEPTACLES FOR INTERLOCKING WITH AN EXTENSIBLE LATCHING DEVICE, EACH SAID RECEPTACLE COMPRISING A CUP HAVING SPACED WALLS DEFINING A SLOT IN THE EDGE OF THE PANEL INSULATING LAYER AND SO LOCATED THAT THE SLOTS IN ADJACENT HEAT INSULATING P ANELS ARE ALIGNED WHEN TWO PANELS ARE INTERCONNECTED, SAID CUP WALLS EXTENDING SUBSTANTIALLY PARALLEL TO THE PLANE OF EACH OF SAID SHELLS, A FLANGE EXTENDING FROM AT LEAST ONE EDGE OF SAID CUP AND LYING IN A PLANE INTERMEDIATE SAID CUP WALLS, SAID ELONGATED MEMBER COMPRISING A SUBSTANTIALLY FLAT STRAP SECURED AT EACH END TO THE FLANGES OF SAID CUPS, SAID STRAP LYING AT LEAST SUBSTANTIALLY WITHIN AN AREA BOUNDED BY THE PLANES OF THE OUTER SURFACES OF SAID CUP WALLS WHEREBY SAID STRIP AND CUPS ARE ALL SPACED A SUBSTANTIAL DISTANCE FROM SAID PANEL SHELLS BY HEAT INSULATING MATERIAL.