Backpack external frame and suspension system

Abstract

A backpack including an external frame is provided. The external frame may include a pair of upright members and a pair of cross members. The cross members may extend transversely to, and may be attached to, the pair of upright members. The upright members and the cross members may be constructed of a laminate structure having layers of carbon fiber and wood, resulting in a lightweight, yet strong, frame.

What is claimed is: 
     
         1 . A backpack comprising:
 an external frame including a pair of upright members and a pair of cross members extending transversely to and attached to the pair of upright members; wherein   the pair of upright members and the pair of cross members are constructed of a laminate structure having layers of carbon fiber and wood.   
     
     
         2 . The backpack of  claim 1 , further comprising a sleeve positioned around each of the pair of upright members and extending along a majority of the length of the pair of upright members. 
     
     
         3 . The backpack of  claim 2 , wherein each sleeve is attached to its respective upright member by the attachment of the pair of cross members to the pair of upright members. 
     
     
         4 . The backpack of  claim 2 , further comprising a torso pad attached to each sleeve. 
     
     
         5 . The backpack of  claim 4 , wherein each torso pad is pivotable relative to the pair of upright members. 
     
     
         6 . The backpack of  claim 4 , further comprising a shoulder strap attached to each sleeve. 
     
     
         7 . The backpack of  claim 6 , wherein a portion of each shoulder strap is slideably retained between a respective torso pad and sleeve. 
     
     
         8 . The backpack of  claim 1 , further comprising a waist belt having an intermediate segment and a pair of padded end segments extending outwardly from the intermediate segment, wherein the intermediate segment defines a pair of pockets that receive lower ends of the pair of upright members. 
     
     
         9 . The backpack of  claim 8 , further comprising a lumbar pad attached to one of the pair of cross members, folded around the intermediate segment of the waist belt, and attached to the pair of upright members to laterally and vertically restrain the waist belt relative to the external frame by maintaining the lower ends of the pair of upright members in the pair of pockets. 
     
     
         10 . The backpack of  claim 9 , wherein the lumbar pad is thicker than the pair of padded end segments of the waist belt. 
     
     
         11 . The backpack of  claim 1 , wherein:
 the pair of cross members comprises an upper cross member and a lower cross member spaced apart from the upper cross member; and   the pair of upright members converge toward one another as the pair of upright members extend downwardly from the upper cross member to the lower cross member.   
     
     
         12 . The backpack of  claim 11 , wherein the pair of upright members extend above the upper cross member to facilitate attachment of a bag to the external frame. 
     
     
         13 . The backpack of  claim 11 , wherein the pair of upright members extend below the lower cross member to facilitate attachment of a waist belt to the external frame. 
     
     
         14 . The backpack of  claim 1 , wherein the pair of upright members have curved profiles. 
     
     
         15 . The backpack of  claim 1 , wherein the pair of upright members and the pair of cross members have rectangular cross sections. 
     
     
         16 . The backpack of  claim 1 , wherein the pair of upright members and the pair of cross members are attached together by four one-degree-of-freedom joints to permit relative lateral movement of the external frame. 
     
     
         17 . The backpack of  claim 1 , wherein the external frame is narrower in width than a wearer's back. 
     
     
         18 . A method of assembling a backpack having an external frame and a suspension system, the method comprising:
 positioning a sleeve having a closed end and an open end over an upright member of the external frame;   positioning a cross member of the external frame transversely to the upright member such that a portion of the sleeve extends between the cross member and the upright member; and   attaching the cross member to the upright member such that the sleeve is trapped between the cross member and the upright member.   
     
     
         19 . The method of  claim 18 , wherein the upright member and the cross member are constructed of a laminate structure having layers of carbon fiber and wood. 
     
     
         20 . The method of  claim 18 , further comprising attaching a torso pad to the sleeve such that the torso pad is pivotable relative to the upright member.