Double tube composite winding shaft

Abstract

A multi-bladder, expandable winding shaft with discontinuous expanding elements is provided including a shaft body made with carbon fiber composites. The shaft comprises an inner and outer tube and two types of profiles, cavity and ledge profiles. The cavity and ledge profiles can be adhesively mounted around the outer surface of the inner tube in an alternating fashion. Ledge profiles hold the expandable bladders and lug assembly. The outer tube can be created by applying layers of carbon fibers, woven or unwoven fabrics or prepregs by filament winding, roll wrapping or any other suitable method. Elongated discrete slots through the outer tube are provided along the ledge profiles. When the bladders are inflated with air, the lugs are pushed outward to engage the inner wall of the core. When deflated, an installed spring system pushes the lugs inward.

What is claimed is: 
     
         1 . A shaft comprising:
 a first, inner tube made of a composite fiber material;   a second, outer tube also made of a composite fiber material;   a plurality of cavity profiles made of a composite fiber material disposed in between the inner and outer tubes; and   a plurality of ledge profiles made of a composite fiber material and disposed in between the inner and outer tubes, the cavity profiles and the ledge profiles being arranged in an alternating manner, wherein one ledge profile is arranged in between two cavity profiles and one cavity profile is arranged in between two ledge profiles.   
     
     
         2 . The shaft according to  claim 1 , wherein the shaft is an expandable shaft comprising:
 a plurality of elongated slots discontinuously distributed along the length of the outer tube;   a plurality of protrusion elements, each protrusion element discontinuously positioned in one of the elongated slots; and   a plurality of expandable elements located in one or more of the ledge profiles.   
     
     
         3 . The shaft according to  claim 1 , wherein the composite fiber materials of the tubes and the profiles comprise one or more of glass, carbon, aramid, or graphite. 
     
     
         4 . The shaft according to  claim 1 , wherein the composite fiber material comprises a matrix of a thermoset resin, including one or more of an epoxy, polyesters, phenolics, vinyl esters, bismaleimide or polyurethane. 
     
     
         5 . The shaft according to  claim 1 , wherein the inner and outer tubes are made by filament winding, roll wrapping, pull-winding, resin transfer molding, vacuum assisted resin transfer molding, Seeman composite resin infusion molding process or structural reaction injection molding process. 
     
     
         6 . The shaft according  claim 1 , wherein the ledge profiles and cavity profiles are made by compression molding, filament winding, pull-winding, resin transfer molding, vacuum assisted resin transfer molding, Seeman composite resin infusion molding or structural reaction injection molding. 
     
     
         7 . The shaft according  claim 2 , wherein the plurality of protrusion elements and the plurality of expandable elements are arranged in the plurality of ledge profiles. 
     
     
         8 . The shaft according to  claim 7 , wherein the plurality of protrusion elements are lug assemblies, each comprising a lug and a lug support. 
     
     
         9 . The shaft according to  claim 8 , wherein the plurality of expandable elements are bladder assemblies, each comprising a bladder configured to be inflated with air, and a bladder support on which the bladder is disposed. 
     
     
         10 . The shaft according to  claim 9 , wherein the bladder support is a single-part system and made of metal, composite, or plastics. 
     
     
         11 . The shaft according to  claim 9 , wherein the bladder support is a multi-part system and made of at least two different materials having different densities. 
     
     
         12 . The shaft according to any one of  claim 9 , wherein the bladder is configured to push the lug outward when the bladder inflated with air, and when deflated, an installed spring system pushes the lug inward. 
     
     
         13 . The shaft according to  claim 1 , wherein one or more of the plurality of cavity profiles are hollow. 
     
     
         14 . The shaft according to  claim 1 , wherein one or more of the plurality of cavity profiles comprise a stiffening bar therein. 
     
     
         15 . The shaft according to  claim 1 , wherein one or more of the plurality of cavity profiles are one-part systems. 
     
     
         16 . The shaft according to  claim 1 , wherein one or more of the plurality of cavity profiles are multi-part systems, comprising a top portion adhered to a bottom portion. 
     
     
         17 . The shaft according to  claim 16 , wherein each of the plurality of ledge profiles is defined laterally by a wall of each adjacent cavity profile and on a base by an outer diameter of the inner tube, and further comprises a bridge element defining the top of the ledge profile. 
     
     
         18 . The shaft according to  claim 1 , wherein the ledge profile comprises a curved upper surface, a curved lower surface, and parallel side walls between the curved upper surface and curved lower surface. 
     
     
         19 . The shaft according to  claim 1 , wherein the composite fibers in the tubes and profiles are multi-directional.