Foldable member

Abstract

A method of manufacturing a foldable member. A plurality of C-section member plies are formed. First and second sets of the C-section member plies are assembled. Two sections of a tube are arranged in an end-to-end manner defining a gap therebetween. The first set of the C-section member plies is secured to one side of the two sections of the tube to bridge the gap therebetween and the second set of C-section member plies is secured to an opposing side of the two tube sections to also bridge the gap therebetween thus forming opposing elongated slots separated by longitudinal strips of material between the slots which fold when subjected to localized buckling forces and which unfold when released. A foldable member manufactured in accordance with this method is also disclosed. Also disclosed is a structure made of one or more such foldable members.

What is claimed is:  
     
         1 . A method of manufacturing a foldable member, the method comprising: 
 forming a plurality of C-section member plies;    assembling a first set of the C-section member plies;    assembling a second set of the C-section member plies;    arranging two sections of a tube in an end-to-end manner defining a gap therebetween;    securing the first set of C-section member plies to one side of the two tube sections of the tube to bridge the gap therebetween; and    securing the second set of C-section member plies to an opposing side of the two tube sections to bridge the gap therebetween thus forming opposing elongated slots in the tube separated by longitudinal strips of C-section member plies material between the slots which fold when subjected to localized buckling forces and which unfold when released.    
     
     
         2 . The method of  claim 1  in which assembling the first set of C-section member plies includes securing all the plies of the first set together.  
     
     
         3 . The method of  claim 1  in which assembling the second set of C-section member plies includes securing all the plies of the second set together.  
     
     
         4 . The method of  claim 1  in which the plurality of C-section member plies are made of composite material.  
     
     
         5 . The method of  claim 1  in which the two tube sections are made of composite material.  
     
     
         6 . The method of  claim 1  in which the plurality of C-section member plies are pultruded into a C-section cross sectional shape.  
     
     
         7 . The method of  claim 1  in which the material of the first and second set of C-section members is the same as the material of the two tube sections.  
     
     
         8 . The method of  claim 1  further including the steps of arranging a third tube section in an end-to-end manner with the two tube sections to define a gap therebetween and securing third and fourth sets of C-section member plies to opposing sides of the third tube section and the two tube sections thus forming sets of longitudinally adjacent opposing elongated slots.  
     
     
         9 . A foldable member comprising: 
 two sections of a tube arranged in an end-to-end manner defining a gap therebetween; and    opposing conforming members each made of multiple plies attached to both tube sections and bridging the gap therebetween defining opposing elongated slots and separated longitudinal strips of material between the slots which fold when subjected to localized buckling forces and which unfold when released.    
     
     
         10 . The foldable member of  claim 9  in which the conforming members have a C-cross sectional shape.  
     
     
         11 . The foldable member of  claim 9  in which the material of the conforming members is the same as the material of the two tube sections.  
     
     
         12 . The foldable member of  claim 11  in which the conforming members are made of composite material and the two tube sections are made of composite material.  
     
     
         13 . The foldable member of  claim 9  in which both sections of the tube comprise a plurality of layers.  
     
     
         14 . The foldable member of  claim 9  in which there are two diametrically opposing elongated slots and two diametrically opposing longitudinal strips.  
     
     
         15 . The foldable member of  claim 9  in which there are a plurality of hinge areas longitudinally spaced from each other along the length of the tube, each hinge area including opposing elongated slots.  
     
     
         16 . The foldable member of  claim 9  in which there are three opposing elongated slots and three opposing elongated strips each longitudinal strip diametrically opposing an elongated slot.  
     
     
         17 . The foldable member of  claim 9  further including a third tube section and sets of longitudinally adjacent opposing elongated slots.  
     
     
         18 . The foldable member of  claim 9  in which the conforming members have a neck down region.  
     
     
         19 . The foldable member of  claim 18  in which the conforming members are secured together only at the neck down region.  
     
     
         20 . The foldable member of  claim 9  in which the conforming members are secured together only where they attach to the tube sections.  
     
     
         21 . The foldable member of  claim 20  in which the conforming members are centrally secured together only where they attach to the tube section.  
     
     
         22 . The foldable member of  claim 9  further including an intermediate rigid member interconnecting the conforming members with a tube section.  
     
     
         23 . The foldable member of  claim 22  in which the intermediate member has spaced fingers, each conforming member received between two spaced fingers.  
     
     
         24 . A structure comprising: 
 a plurality of joined truss members;    a selected number of said truss members each including a foldable member comprising: 
 two sections of a tube arranged in an end-to-end manner defining a gap therebetween; and  
 opposing conforming members each made of multiple plies attached to both tube sections and bridging the gap therebetween defining opposing elongated slots and separated longitudinal strips of material between the slots which fold when subjected to localized buckling forces and which unfold when released.  
   
     
     
         25 . The structure of  claim 24  in which the conforming members have a C-cross sectional shape.  
     
     
         26 . The structure of  claim 24  in which the material of the conforming members is the same as the material of the two tube sections.  
     
     
         27 . The structure of  claim 26  in which the conforming members are made of composite material and the two tube sections are made of composite material.  
     
     
         28 . The structure of  claim 24  in which both sections of the tube comprise a plurality of layers.  
     
     
         29 . The structure of  claim 24  in which there are two diametrically opposing elongated slots and two diametrically opposing longitudinal strips.  
     
     
         30 . The structure of  claim 24  in which there are a plurality of hinge areas longitudinally spaced from each other along the length of the tube, each hinge area including opposing elongated slots.  
     
     
         31 . The structure of  claim 24  in which there are three opposing elongated slots and three opposing elongated strips each longitudinal strip diametrically opposing an elongated slot.  
     
     
         32 . The structure of  claim 24  in which the multiple plies are secured together before the conforming members are attached to the tube sections.  
     
     
         33 . The structure of  claim 24  in which the plies are pultruded into a C-section cross sectional shape.  
     
     
         34 . The structure of  claim 24  further including a third tube section and longitudinally adjacent slots opposing each other around the circumference of the foldable member.