Cellular structural material

Claim 1

A DOUBLE-SKIN SANDWICH STRUCTURE COMPRISING TWO FACING MEMBERS HAVING DISPOSED THEREBETWEEN AND BONDED THERETO A CELLULAR STRUCTURAL ELEMENT COMPRISING AT LEAST THREE STRIPS OF MATERIAL ARRANGED FACE-TO-FACE IN PARALLEL RELATIONSHIP, AND A SERIES OF SPACING MEMBERS DISPOSED BETWEEN AND INTERCONNECTING THE OPPOSING FACES OF EACH PAIR OF NEIGHBORING STRIPS, EACH STRIP AND SPACING MEMBER BEING CAPABLE OF WITHSTANDING COMPRESSIVE FORCES IN ITS OWN PLANE WITHOUT DEFORMING, EACH OF SAID SPACING MEMBERS HAVING A FIRST FLANGE PORTION AT ONE END THEREOF AND A SECOND FLANGE PORTION AT THE OPPOSITE END THEREOF SAID FIRST FLANGE PORTION EXTENDING IN A FIRST DIRECTION, SAID SECOND FLANGE PORTION EXTENDING IN A SECOND DIRECTION OPPOSITE THEREFROM WHEREBY SAID SPACING MEMBER IS JOINED TO THE TWO STRIPS WHICH IT INTERCONNECTS BY HAVING AT LEAST A PART OF ONE FLANGE PORTION BONDED TO ONE OF SAID OPPOSING FACES AND AT LEAST A PART OF THE OTHER FLANGE PORTION BONDED TO THE OTHER OF SAID OPPOSING FACES, THE PORTION OF THE SPACING MEMBER BETWEEN SAID FIRST AND SECOND FLANGE PORTIONS ADAPTED TO BE PERPENDICULARLY TRANSVERSE TO SAID STRIPS WHEN THE COLLAPSIBLE CELLULAR STRUCTURAL ELEMENT IS FULLY EXTENDED, SAID SPACING MEMBERS BETWEEN EACH PAIR OF NEIGHBORING STRIPS BEING OF EQUAL LENGHT AND SPACED FROM ONE ANOTHER A DISTANCE SUCH THAT WHEN THE ELEMENT IS COLLAPSED THE FIRST FLANGE PORTION OF EACH SPACING MEMBER BETWEEN EACH PAIR OF NEIGHBORING STRIPS IS CLOSELY ADJACENT THE SECOND FLANGE PORTION OF ONE OF THE SPACING MEMBERS ADJACENT THERETO AND THE SECOND FLANGE PORTION OF EACH SPACING MEMBER BETWEEN EACH PAIR OF NEIGHBORING STRIPS IS CLOSELY ADJACENT THE FIRST FLANGE PORTION OF THE OTHER SPACING MEMBER ADJACENT THERETO WHEREBY WHEN THE ELEMENT IS COLLAPSED THE SPACING MEMBERS BETWEEN EACH PAIR OF NEIGHBORING STRIPS LIE IN A PLANE SUBSTANTIALLY PARALLEL TO SAID STRIPS, AND WHEREIN THE SPACING MEMBERS INTERCONNECTING SAID THREE STRIPS ARE JOINED TO SAID STRIPS IN A MANNER SUCH THAT WHEN THE STRIPS ARE SPACED APART BY A DISTANCE LESS THAN THE MAXIMUM PERMITTED BY THE LENGTH OF THE SPACING MEMBERS, THE SERIES OF SPACING MEMBERS DEFINED ON EITHER SIDE OF THE CENTRAL STRIP ARE DECLINED IN OPPOSITE DIRECTIONS.