Foldable member

Abstract

A foldable member in the shape of a tube with at least one predetermined hinge area along the length of the tube and opposing sets of elongated slots in the tube at the hinge area thereof forming separated longitudinal strips of tube material between the slots which fold when subjected to localized buckling forces, each slot of each set of elongated slots separated longitudinally along the length of the tube from each adjacent slot by a bridge element of tube material. A collapsible structure constructed of such foldable members.

1 . A foldable member comprising: 
 at least a first tube; 
 at least one predetermined hinge area along the length of the first tube; and  
 opposing sets of elongated slots in the tube at the hinge area  
 thereof forming separated longitudinal strips of tube material between the slots which fold when subjected to localized buckling forces,  
 each slot of each set of elongated slots separated longitudinally along the length of the tube from each adjacent slot by a bridge element of tube material.  
   
     
     
         2 . The foldable member of  claim 1  in which the opposing sets of elongated slots are diametrically opposed from each other on the tube.  
     
     
         3 . The foldable member of  claim 1  in which each slot in each set of slots is diametrically opposed from a slot in the opposing set of slots.  
     
     
         4 . The foldable member of  claim 1  in which there are two sets of slots.  
     
     
         5 . The foldable member of  claim 4  in which there are two slots in each set of slots.  
     
     
         6 . The foldable member of  claim 1  in which there are two sets of slots and two slots in each set.  
     
     
         7 . The foldable member of  claim 1  in which there is a stress relieving member attached to each bridge element on the inside of the tube.  
     
     
         8 . The foldable member of  claim 1  in which the tube is made of a plastic material.  
     
     
         9 . The foldable member of  claim 1  in which the tube is made of a composite material.  
     
     
         10 . The foldable member of  claim 9  in which the composite material includes a tri axial braid of fibers in a resin matrix.  
     
     
         11 . The foldable member of  claim 1  in which there are a plurality of hinge areas spaced from each other along the length of the tube, each hinge area including opposing sets of elongated slots.  
     
     
         12 . The foldable member of  claim 1  further including an electrical conductor disposed in the tube.  
     
     
         13 . The foldable member of  claim 1  further including at least one transducer device located proximate a hinge area for controlling the folding of the longitudinal strips of tube material.  
     
     
         14 . The foldable member of  claim 1  further including slot reinforcing members disposed in the slots.  
     
     
         15 . The foldable member of  claim 1  in which the elongated slots are triangle shaped.  
     
     
         16 . The foldable member of  claim 1  in which the elongated slots are diamond shaped.  
     
     
         17 . The foldable member of  claim 1  in which there are four slots in each set of slots, each slot of a pair of the four slots opposing another slot.  
     
     
         18 . The foldable member of  claim 1  in which each slot has a reduced diameter portion.  
     
     
         19 . The foldable member of  claim 1  further including a second tube disposed inside the first tube.  
     
     
         20 . The foldable member of  claim 19  in which the second tube includes opposing sets of elongated slots at the hinge area thereof.  
     
     
         21 . A collapsible structure comprising: 
 a plurality of joined members;    a selected number of said members each including: 
 a tube; 
 at least one predetermined hinge area along the length of the tube; and  
 
 opposing sets of elongated slots in the tube at the hinge area thereof forming separated longitudinal strips of tube material between the slots which fold when subjected to localized buckling forces,  
 each slot of each set of elongated slots separated longitudinally along the length of the tube from each adjacent slot by a bridge element of tube material.  
   
     
     
         22 . A foldable member comprising: 
 at least a first tube made of layers of material;    at least one predetermined hinge area along the length of the first tube; and    a plurality of opposing elongated slots in the tube through the layers of material forming separated longitudinal strips of layers of tube material between the slots which fold when subjected to localized buckling forces.    
     
     
         23 . The foldable member of  claim 22  in which first tube includes a sheet of plastic material wrapped around itself several times forming the layers of tube material.  
     
     
         24 . The foldable member of  claim 23  further including an adhesive securing the layers of plastic material to each other at selected locations along the length of the tube.  
     
     
         25 . The foldable member of  claim 24  in which the adhesive is a tape.  
     
     
         26 . The foldable member of  claim 24  in which the sheet of plastic material comes from a roll of plastic stock material and has a round memory.  
     
     
         27 . The foldable member of  claim 22  in which the layers of material are laminated to each other except at the predetermined hinge area.