Ribbed core dual wall structure

Abstract

An elongated composite tube made up of an inner tube 42 and an outer tube 44 (FIG. 3 ) with a plurality of elongated helical ribs disposed between the inner tube and the outer tube in a supporting relationship to both. A slinky like toy made from the composite tube is also disclosed, as is a method of making both.

1. A composite tube  structure comprising at least one axially elongated, substantially rigid inner tubular wall  member having an outwardly directed substantially cylindrical surface, at least one axially elongated, substantially rigid outer tubular wall  member having an inwardly directed substantially cylindrical surface radially spaced from said inner tubular wall  outwardly directed surface, and a plurality of substantially rigid ribs helically  disposed in the space between the inner and outer walls,  inwardly directed surface and the outwardly directed surface,
   wherein a first plurality of said ribs are disposed in a positive angular direction other than perpendicular with respect to at least one of said surfaces and a second plurality of said ribs are disposed in a negative angular direction with respect to said perpendicular,    
   wherein at least one pair of said positive and negative non - perpendicular ribs that are next adjacent to each other are in contact with both said outwardly directed and said inwardly directed surfaces wherein at least some of said ribs are joined to both said inner and outer walls along  over at least  a sufficient  portion of the axial length  of said wallsstructure;  
   wherein said pair of ribs, to maintain the spacing between said walls  together with portions, respectively, of said surfaces intercepted by said ribs, form substantially triangular or trapezoidal truss cells at least over said portion of said structure, and    
   wherein said structure is axially twisted such that said inner and outer members, and at least some of said truss cells, are disposed, over at least a portion of the length of the structure, in a composite of longitudinal and a circumferential directions.    
 
     
     
       2. A composite tube  structure as claimed in  claim 1  wherein said inner  inwardly directed and outer walls  said outwardly directed surfaces are concentric over at least a portion of said structure. 
     
     
       3. A composite tube  structure as claimed in  claim 1  wherein some of said ribs are disposed substantially normal to said inner wall  outwardly directed surface. 
     
     
       4. A composite tube  structure as claimed in  claim 1  wherein at least some  all of said ribs are disposed at an angle, that differs from perpendicular, with respect to said inner tubular wall  outwardly directed surface; and wherein said entire structure is at least partially helical in orientation. 
     
     
       5. A composite tube as claimed in  claim 1  wherein at least some of said ribs alternate in the direction of their angle with resect to normal to said inner tube. 
     
     
       6. A composite tube as claimed in  claim 1   An unseamed structure comprising an inner member having a substantially cylindrical outwardly directed wall and an outer tubular member having an inwardly directed wall, and a plurality of ribs at least some of which are in supporting relationship to said members, wherein at least some of said ribs are simultaneously contacted and adhered to at least one  an integral part of both of said inner and outer tubes  inwardly directed and outwardly directed surfaces, respectively, as well as to a next, adjacent rib at substantially the same location of said rib and tube  on said surfaces so as to form generally  form, together with an intercepted portion of either said inwardly directed surface or said outwardly directed surface, respectively, generally  at least one substantially triangular longitudinal  truss cells  and wherein said entire structure, comprising said inner member, said outer member and integral triangular truss cell is twisted so that the entire structure has a circumferential as well as longitudinal disposition. 
     
     
       7. A composite tube  structure as claimed in  claim 6  wherein all of said ribs are longitudinally contacted and adhered to  an integral part of both of said inner and outer tubes  inwardly directed and outwardly directed surfaces, respectively. 
     
     
       8. A composite tube  structure as claimed in  claim 6  wherein all of said ribs are alternately disposed at positive and negative angles, respectively, with respect to a perpendicular to said wells  surfaces. 
     
     
       9. A composite tube  structure as claimed in  claim 1  wherein at least some of said ribs are simultaneously contacted and adhered to  seamlessly integrated with at least one of said inner and outer tubes  surfaces, respectively, at a location that is spaced from the location where the  a next adjacent ribs are contacted with and adhered to said inner and outer tubes  is seamlessly integrated with at least one of said surfaces so as to  to, together with the inwardly directed and outwardly directed surfaces disposed between said rib integration points, respectively, form generally longitudinal  truss cells having a  substantially trapezoidal cross sections. 
     
     
       10. A composite tube  structure as claimed in  claim 9  wherein all of said ribs are alternately disposed at positive and negative angles away from normal with respect to said inner and outer tubes  with respect to perpendicular to said inwardly directed surface and said outwardly directed surface, respectively. 
     
     
       11. A composite tube  structure as claimed in  claim 1  wherein said ribs  truss cells extend the entire longitudinal length of said composite tube  structure. 
     
     
       12. A composite tube  structure as claimed in  claim 1  wherein all of said ribs are disposed helically between said inner and outer tubes  said entire structure is in the shape of a helix. 
     
     
       13. A composite tube  structure as claimed in  claim 1  wherein consisting essentially of one  a monolith consisting essentially of an inner substantially rigid tube and one  tubular member, an outer substantially rigid tube  tubular member, and a plurality of ribs in supporting and spacing relationship to said inner and outer tubular members;
   wherein at least one pair of next adjacent ribs are alternately disposed at positive and negative angles with respect to a perpendicular to said surfaces; and    
   wherein said tubular members and said ribs are disposed in a helical configuration.    
 
     
     
       14. A composite tube  structure as claimed in  claim 1  wherein said tubes  members are substantially concentric and have a substantially circular cross section. 
     
     
       15. A composite tube as claimed in  claim 1  wherein at least some of said ribs are disposed at angles other than perpendicular to said inner and outer walls. 
     
     
       16. A structure as claimed in  claim 1  which is formed as a monolith. 
     
     
       17. A structure as claimed in  claim 1  comprising a plurality of said truss cells substantially equidistantly circumferentially distributed about the circumference of said outwardly directed surface. 
     
     
       18. A structure as claimed in  claim 6  comprising a plurality of said truss cells substantially equidistantly circumferentially distributed about the circumference of said outwardly directed surface. 
     
     
       19. A structure as claimed in  claim 9  comprising a plurality of said truss cells substantially equidistantly circumferentially distributed about the circumference of said outwardly directed surface. 
     
     
       20. A structure as claimed in  claim 6  comprising a plurality of said substantially triangular truss cells having apexes that are directed toward said outwardly directed surface and said inwardly directed surface, alternately. 
     
     
       21. A structure as claimed in  claim 9  comprising a plurality of said substantially trapezoidal truss cells wherein next adjacent trapezoidal truss cells have shorter sides that are alternately a portion of said outwardly directed surface and said inwardly directed surface, respectively. 
     
     
       22. A structure as claimed in  claim 1  consisting essentially of a monolithic extrudate. 
     
     
       23. A structure as claimed in  claim 6  consisting essentially of a monolithic extrudate. 
     
     
       24. A structure as claimed in  claim 9  consisting essentially of a monolithic extrudate. 
     
     
       25. A monolithic, seamless plastic extrudate structure comprising an inner member having an outwardly directed, substantially cylindrical surface; an outer member having an inwardly directed, substantially cylindrical surface spaced from said outwardly directed surface; and a plurality of ribs, disposed between and integral with said inner and outer members, and forming together therewith a plurality of truss cells each comprising next adjacent positively angularly directed and negatively angularly directed ribs, with respect to a perpendicular to said outwardly directed surface, and a portion of at least one of said outwardly directed surface and said inwardly directed surface intercepted by said ribs;
   wherein at least one truss cell comprises a line where a rib, disposed at a negative angle to said perpendicular, intersects said outwardly directed surface, and a line where a next adjacent rib, disposed at a positive angle to said perpendicular, intersects said outwardly directed surface, wherein said lines are proximate to each and at most slightly separated from each other intercepting at most a small portion of said surface and thereby forming truss cells that are non - rectangular;        wherein said monolithic structure is twisted about a longitudinal axis of said structure so that at least a portion of each of said inner member, said outer member and said ribs are disposed in a direction that is a composite of both longitudinal and circumferential directions.     
     
     
       26. An extrudate as claimed in  claim 25  wherein said disposition is helical. 
     
     
       27. An extrudate as claimed in  claim 25  wherein said disposition is for the entire longitudinal length of said structure. 
     
     
       28. An extrudate as claimed in  claim 25  wherein the intersection between said ribs and said surfaces occurs during extrusion and is seamless. 
     
     
       29. An extrudate as claimed in  claim 25  wherein at least some of said ribs are substantially rectangular in cross section. 
     
     
       30. An extrudate as claimed in  claim 25  wherein said inner member is tubular. 
     
     
       31. An extrudate as claimed in  claim 25  comprising polyethylene. 
     
     
       32. An extrudate as claimed in  claim 25  comprising polystyrene. 
     
     
       33. The structure product of a process, said process comprising:
   extruding, from an extruder, a monolithic molten structure comprising an inner member, an outer member spaced from said inner member, and a plurality of ribs extending between, and integral with, said inner and outer members, wherein at least a portion of said ribs are disposed at an angle, other than right, with respect to a perpendicular to said inner member;        cooling said molten structure sufficient to impart structural integrity to said structure;        pulling said cooled structure along its longitudinal axis;        twisting said cooled structure about its longitudinal axis;        whereby causing said structure in its molten state as it is extruded to be simultaneously pulled away from the extruder and twisted about its longitudinal axis while still in a deformable condition; and        whereby causing all of said extruded molten structure to be twisted into an orientation such that all of said structure has a longitudinal component and a circumferential component while still in a deformable state;        cooling said integral structure sufficient to fix a twist in all of said structure; and        recovering finite lengths of said cooled, twisted structure.     
     
     
       34. The product claimed in  claim 33  wherein said inner member, said outer member and said ribs are commonly extruded and thus constitute a seamless monolithic structure. 
     
     
       35. The product claimed in  claim 33  wherein said pulling and twisting steps are applied to said extrudate after it has solidified, and wherein pulling and twisting said solidified structure causes said molten extrudate to be pulled and twisted while it is in a deformable state. 
     
     
       36. A helically configured composite tube comprising at least one axially elongated, substantially rigid inner tubular wall, at least one axially elongated, substantially rigid outer tubular wall spaced from said inner tubular wall, and a plurality of substantially rigid ribs disposed in the space between said the inner and outer walls;
   wherein at least some of said ribs are joined to both said inner and outer walls along a sufficient portion of the axial length of said walls to maintain space between the walls;        wherein at least some of said ribs are simultaneously contacted and seamlessly adhered to said inner and outer tubes, respectively, as well as to a next adjacent rib at substantially the same location of said rib and tube to form generally triangular truss cells; and        wherein said composite tube has been twisted about its longitudinal axis into a helix.     
     
     
       37. A composite tube as claimed in  claim 36  that is a seamless monolithic extrudate. 
     
     
       38. A helically configured composite structure comprising at least one axially elongated, substantially rigid inner cylindrical wall, at least one axially elongated, substantially rigid outer tubular wall concentric with, and spaced from, said inner cylindrical wall, and a plurality of substantially rigid ribs disposed in space between said the inner and outer walls;
   wherein at least some of said ribs are integral with both said inner and outer walls along a sufficient portion of the axial length of said walls to maintain the space between the walls;        wherein said ribs comprise first ribs disposed at a positive angle with respect to a perpendicular to said inner and outer tubular walls, and second ribs disposed at a negative angle with respect to a perpendicular to said inner and outer walls,        wherein at least some of said first ribs are contacted with and seamlessly integral with said inner cylindrical wall and said outer tube, respectively,        wherein at least some of said second ribs are contacted with and seamlessly adhered to said inner cylindrical and outer tubular walls such that a positively angled rib and a next adjacent negatively angled rib are integral with said inner cylinder or outer tubular wall at first spaced apart locations and are integral with the other of said inner or outer tubular wall at second locations that are further spaced apart than said first locations;        wherein said next adjacent ribs and the intercepted portions of said inner and outer tubular walls form truss cells having a generally trapezoidal cross section; and        wherein the entirety of said composite tube is twisted about its longitudinal axis into a helix.     
     
     
       39. A composite tube as claimed in  claim 38  that is a single extrudate monolith. 
     
     
       40. A composite tube as claimed in  claim 36  wherein said ribs are not substantially thicker than one of said tubular walls. 
     
     
       41. A composite tube as claimed in  claim 38  wherein said ribs are not substantially thicker than one of said tubular walls. 
     
     
       42. A composite tube comprising at least one axially elongated, substantially rigid inner tubular wall, at least one axially elongated, substantially rigid outer tubular wall spaced from said inner tubular wall, and a plurality of substantially rigid ribs disposed in the space between the inner and outer walls; wherein at least some of said ribs are joined to both the inner and outer walls along a sufficient portion of the axial length of said walls to maintain the spacing between the walls and wherein at least some of said ribs are simultaneously contacted and adhered to at least one of said inner and outer tubes, respectively, as well as to a next adjacent rib at substantially the same location of said rib and tube so as to form generally triangular longitudinal truss cells;
   wherein all of the elements of said tube have circumferential as well as longitudinal disposition.     
     
     
       43. A composite tube as claimed in  claim 42  wherein said truss cells follow a substantially helical path for at least a substantial portion of their length. 
     
     
       44. A composite tube comprising at least one axially elongated, substantially rigid inner tubular wall, at least one axially elongated, substantially rigid outer tubular wall spaced from said inner tubular wall, and a plurality of substantially rigid ribs disposed in the space between the inner and outer walls; wherein at least some of said ribs are joined to both the inner and outer walls along a sufficient portion of the axial length of said walls to maintain the spacing between the walls and wherein at least some of said ribs are simultaneously contacted and adhered to at least one of said inner and outer tubes, respectively, at a location that is spaced from the location where the next adjacent ribs are contacted with and adhered to said inner and outer tubes so as to form generally longitudinal truss cells having a substantially trapezoidal cross section;
   wherein all of the components of said tube are disposed in a pattern having longitudinal and circumferential vector components.     
     
     
       45. A composite tube comprising at least one axially elongated, substantially rigid inner tubular wall, at least one axially elongated, substantially rigid outer tubular wall spaced from said inner tubular wall, and a plurality of substantially rigid ribs disposed in the space between the inner and outer walls; wherein at least some of said ribs are integral with both the inner and outer walls along a sufficient portion of the axial length of said walls to maintain the spacing between the walls and wherein at least some of said ribs are simultaneously contacted and adhered to at least one of said inner and outer tubes, respectively, as well as to a next adjacent rib at substantially the same location of said rib and tube so as to form generally triangular longitudinal truss cells, wherein all of said ribs are alternately disposed at positive and negative angles, respectively, with respect to a perpendicular to said walls, and wherein all of the elements of said composite tube are disposed along a path that has longitudinal as well as circumferential vector components. 
     
     
       46. A composite tube as claimed in  claim 45  wherein said truss cells follow a path that is directed in a substantially circumferential as well as longitudinal direction. 
     
     
       47. A composite tubular monolith having circumferential as well as longitudinal disposition and comprising at least one axially elongated, substantially rigid inner tubular wall, at least one axially elongated, substantially rigid outer tubular wall spaced from said inner tubular wall, and a plurality of substantially rigid ribs helically disposed in the space between the inner and outer walls; wherein at least some of said ribs are joined to both the inner and outer walls along a sufficient portion of the axial length of said walls to maintain the spacing between the walls and wherein at least some of said ribs are simultaneously contacted with and an integral part of at least one of said inner and outer tubes, respectively, at a location that is spaced from the location where the next adjacent ribs are contacted with said inner and outer tubes so as to form generally longitudinal truss cells having a substantially trapezoidal cross section and wherein all of the ribs are alternatively disposed at positive and negative angles away from normal with respect to a perpendicular from said inner and outer tubes; wherein all of the elements of said monolith have a helical configuration.