Ultra Lightweight Segmented Ladder/Bridge System

Abstract

A dual-use ladder and bridge modular system preferably includes tubes, gussets, flanges, and/or joints. In a preferred embodiment, the tubes, gussets, flanges, and/or joints are made of carbon fiber. A method connects and disconnects modular carbon fiber ladder segments. Another method creates a lightweight carbon-fiber beam with exceptionally high stiffness and strength using a combination of carbon-fiber braid material, uni-directional cloth, and pultruded carbon-fiber strips. A carbon fiber ladder segment and tube connectors are also disclosed.

1 - 14 . (canceled) 
     
     
         15 . A method of fabricating a carbon fiber tube, comprising the steps of:
 a) sandwiching a plurality of uni-directional carbon-fiber strips within a carbon-fiber tube between an inner carbon fiber layer of the carbon fiber tube and an outer carbon fiber layer of the carbon fiber tube; and   b) adhering the uni-directional carbon-fiber strips to the carbon fiber tube.   
     
     
         16 . The method of  claim 15 , wherein the uni-directional carbon-fiber strips are placed on two opposing sides of the tube. 
     
     
         17 . The method of  claim 15 , wherein the uni-directional carbon-fiber strips comprise pultruded carbon-fiber strips. 
     
     
         18 . The method of  claim 15 , wherein the inner carbon fiber layer and the outer carbon fiber layer comprise a carbon fiber woven material. 
     
     
         19 . The method of  claim 15 , wherein the outer carbon fiber layer comprises a braided carbon fiber material and the inner carbon fiber layer comprises a material selected from the group consisting of a braided carbon-fiber material and a plain-weave carbon fiber material. 
     
     
         20 . The method of  claim 15 , further comprising the substep of wrapping a uni-directional carbon fiber around the inner carbon fiber layer. 
     
     
         21 . A modular system comprising:
 a) a plurality of carbon fiber tubes, each carbon fiber tube having a first end and a second end;   b) a spliced joint connector located at at least one of the first end and the second end of each carbon fiber tube;   c) at least one modular element, wherein the modular element mates with at least one end of the carbon fiber tubes;   wherein the spliced joint connector on an end of a first carbon fiber tube mates either with a sleeve formed by a hollow portion of an interior of a second carbon fiber tube or with the modular element to form a structure.   
     
     
         22 . The modular system of  claim 21 , wherein the modular element is U-shaped. 
     
     
         23 . The modular system of  claim 21 , wherein the modular element forms an angle between 30 and 150 degrees. 
     
     
         24 . The modular system of  claim 21 , wherein the modular element comprises a hook connected to the spliced joint connector on at least one of the carbon fiber tubes. 
     
     
         25 . The modular system of  claim 21 , wherein the modular element comprises a pair of feet, wherein the feet are located on a bottom end of at least one of the carbon fiber tubes such that the feet provide friction for the structure when the feet are placed on the ground. 
     
     
         26 . The modular system of  claim 21 , wherein the modular system is a modular ladder/bridge system comprising:
 a) at least two ladder segments, each ladder segment comprising:
 i) a pair of tubular carbon fiber side rails, each carbon fiber side rail having a first end and a second end; 
 ii) at least one carbon fiber rung perpendicular to the carbon fiber side rails, wherein the carbon fiber rung connects the carbon fiber side rails of the ladder segment; 
   wherein the spliced joint connector on an end of a first carbon fiber side rail mates either with a sleeve formed by a hollow portion of an interior of a second carbon fiber side rail of a second ladder segment or with the modular element to form the structure.   
     
     
         27 . The modular system of  claim 26 , wherein the rung is detachable from the side rail. 
     
     
         28 . The modular system of  claim 26 , wherein the carbon fiber side rails are set at an angle relative to a vertical direction. 
     
     
         29 - 37 . (canceled)