Double knee jointed longeron truss for space structures

Abstract

A deployable truss having multiple rigid transverse sections, forming triangles, rectangles or other shapes, where adjacent transverse sections are connected by multiple three-piece longerons hinged together and to the transverse sections. In a folded configuration, the each longeron has a central link that maintains spacing between adjacent transverse sections, providing stowage space for load modules such as stacks of deployable panels. The longeron structure also ensures that deployment of the truss proceeds in a linear fashion and that the deployed truss is relatively rigid. Multiple stay wires coupling adjacent transverse sections further enhances structural rigidity.

1 . A deployable truss, comprising: 
 a plurality of similar transverse sections, each comprising multiple members joined to form a rigid, generally coplanar structure, the transverse sections being arrayed in a parallel spaced relationship along a longitudinal axis generally perpendicular to the transverse sections; and    located between adjacent transverse sections, a plurality of foldable longerons connected by hinges to the transverse sections, and deployable from a folded configuration that minimizes spacing between adjacent transverse sections and a deployed configuration that maximizes the spacing and forms a rigid truss structure with the transverse sections;    wherein each of the foldable longerons comprises first and second longeron arms, each having first and second ends and connected by their first ends to corresponding hinge points on adjacent transverse sections, and a longeron link connected to the second ends of the first and second longeron arms by additional hinge points.    
   
   
       2 . A deployable truss as defined in  claim 1 , wherein: 
 each transverse section of the truss is rectangular; and    four foldable longerons are connected between corresponding corners of adjacent rectangular transverse sections of the truss.    
   
   
       3 . A deployable truss as defined in  claim 1 , wherein: 
 each transverse section of the truss is triangular; and    three foldable longerons are connected between corresponding corners of adjacent triangular transverse sections of the truss.    
   
   
       4 . A deployable truss as defined in  claim 1 , and further comprising: 
 means for urging the transverse sections apart from each other along the longitudinal axis, wherein the longerons unfold to a fully extended position in which the truss is said to be deployed.    
   
   
       5 . A deployable truss as defined in  claim 4 , wherein the truss is foldable to a compact configuration in which the longeron arms are pivoted into positions generally coplanar with the transverse sections to which they are attached, and the longeron links remain perpendicular to the transverse sections and determine a minimum spacing between the transverse sections, to allow room for stowing other deployable components.  
   
   
       6 . A deployable truss as defined in  claim 1 , and further comprising: 
 disposed between and connected to adjacent transverse sections, a plurality of stay wires that enhance the structural rigidity of the deployed truss.    
   
   
       7 . A deployable truss, comprising: 
 a plurality of transverse sections, each of which has four structural members connected to form a rectangle, the rectangular transverse sections being arrayed in a parallel spaced relationship along a longitudinal axis generally perpendicular to the rectangular transverse sections; and    located between successive pairs of adjacent rectangular transverse sections, four foldable longerons connected by pin hinges to the respective corners of the rectangular transverse sections, and deployable from a folded configuration that minimizes spacing between adjacent transverse sections and a deployed configuration that maximizes the spacing and forms a rigid truss structure with the transverse sections;    wherein each of the foldable longerons comprises first and second longeron arms, each having first and second ends and connected by their first ends to corresponding hinge points at corners of adjacent rectangular transverse sections, and a longeron link connected to the second ends of the first and second longeron arms by additional hinge points;    and wherein the deployable truss further comprises a plurality of stay wires connected between non-opposed corners of adjacent rectangular transverse sections, to provide enhanced rigidity;    and wherein the longeron links determine a minimum spacing between adjacent rectangular transverse sections in the folded configuration, allowing other components to be stowed between the rectangular transverse sections.    
   
   
       8 . A deployable truss as defined in  claim 7 , and further comprising: 
 means for urging the rectangular transverse sections apart from each other and into the deployed configuration of the truss in which the longerons are fully extended; and    means for locking the longerons in their fully extended positions.    
   
   
       9 . A deployable truss, comprising: 
 a plurality of transverse sections, each of which has three structural members connected to form a triangle, the triangular transverse sections being arrayed in a parallel spaced relationship along a longitudinal axis generally perpendicular to the triangular transverse sections; and    located between successive pairs of adjacent triangular transverse sections, three foldable longerons connected by pin hinges to the respective corners of the triangular transverse sections, and deployable from a folded configuration that minimizes spacing between adjacent transverse sections and a deployed configuration that maximizes the spacing and forms a rigid truss structure with the transverse sections;    wherein each of the foldable longerons comprises first and second longeron arms, each having first and second ends and connected by their first ends to corresponding hinge points at corners of adjacent triangular transverse sections, and a longeron link connected to the second ends of the first and second longeron arms by additional hinge points;    and wherein the deployable truss further comprises a plurality of stay wires connected between non-opposed corners of adjacent rectangular transverse sections, to provide enhanced rigidity;    and wherein the longeron links determine a minimum spacing between adjacent triangular transverse sections in the folded configuration, allowing other components to be stowed between the triangular transverse sections.    
   
   
       10 . A deployable truss as defined in  claim 9 , and further comprising: 
 means for urging the triangular transverse sections apart from each other and into the deployed configuration of the truss in which the longerons are fully extended; and    means for locking the longerons in their fully extended positions.