Adjustable flex backpack frame

Abstract

A backpack including an adjustable frame including at least one reinforcement stay having a first side, a second side opposite the first side, and a longitudinal axis, wherein the reinforcement stay includes an asymmetrical flex material configured such that a flexural modulus of the reinforcement stay in a first direction, in which the reinforcement stay flexes about the longitudinal axis such that the first side becomes concave, is greater than a flexural modulus in a second opposing direction, in which the reinforcement stay flexes about the longitudinal axis such that the second side becomes concave, wherein the backpack is configured such that the reinforcement stay can be selectively oriented in either a first orientation, in which the first side of the reinforcement stay faces toward a wearer of the backpack, or a second orientation, in which the second side of the reinforcement stay faces toward the wearer of the backpack.

What is claimed is: 
     
         1 . A backpack, comprising:
 an adjustable frame comprising at least one reinforcement stay having a first side, a second side opposite the first side, and a longitudinal axis,
 wherein the at least one reinforcement stay comprises an asymmetrical flex material configured such that a flexural modulus of the at least one reinforcement stay in a first direction, in which the at least one reinforcement stay flexes about the longitudinal axis such that the first side becomes concave, is greater than a flexural modulus of the at least one reinforcement stay in a second direction, in which the at least one reinforcement stay flexes about the longitudinal axis such that the second side becomes concave, and
 wherein the second direction is opposite the first direction, 
 
   wherein the backpack is configured such that the at least one reinforcement stay can be selectively oriented in either a first orientation or a second orientation,
 wherein, in the first orientation, the first side of the at least one reinforcement stay faces toward a wearer of the backpack, and 
 wherein, in the second orientation, the second side of the at least one reinforcement stay faces toward the wearer of the backpack. 
   
     
     
         2 . The backpack of  claim 1 , wherein the asymmetrical flex material is configured to increase a stiffness of the adjustable frame by a factor of from 2:1 to 5:1. 
     
     
         3 . The backpack of  claim 1 , wherein the asymmetrical flex material is configured to be subjected to repeated bending and release cycles at 50% of a force required to break the asymmetrical flex material without breaking the asymmetrical flex material. 
     
     
         4 . The backpack of  claim 1 , wherein the asymmetrical flex material is configured to be subjected to repeated bending and release cycles at 50% of a force required to break the asymmetrical flex material without breaking the asymmetrical flex material for up to 5,000 flex and release cycles. 
     
     
         5 . The backpack of  claim 1 , wherein the adjustable frame comprises a plurality of reinforcement stays. 
     
     
         6 . The backpack of  claim 1 , wherein the adjustable frame is an external frame. 
     
     
         7 . The backpack of  claim 1 , wherein the adjustable frame is an internal frame. 
     
     
         8 . The backpack of  claim 1 , wherein the flexural modulus of the at least one reinforcement stay in the first direction relative to the second direction is from 1.5:1 to 6:1. 
     
     
         9 . A backpack, comprising:
 at least one reinforcement stay having a first side, a second side opposite the first side, and a longitudinal axis,
 wherein the at least one reinforcement stay comprises an asymmetrical flex material configured such that a flexural modulus of the at least one reinforcement stay in a first direction, in which the at least one reinforcement stay flexes about the longitudinal axis such that the first side becomes concave, is greater than a flexural modulus of the at least one reinforcement stay in a second direction, in which the at least one reinforcement stay flexes about the longitudinal axis such that the second side becomes concave, and
 wherein the second direction is opposite the first direction, 
 
   wherein the backpack is configured such that the at least one reinforcement stay can be selectively oriented in either a first orientation or a second orientation,
 wherein, in the first orientation, the first side of the at least one reinforcement stay faces toward a wearer of the backpack, and 
   
       wherein, in the second orientation, the second side of the at least one reinforcement stay faces toward the wearer of the backpack. 
     
     
         10 . The backpack of  claim 9 , wherein the asymmetrical flex material is configured to increase a stiffness of the backpack by a factor of from 2:1 to 5:1. 
     
     
         11 . The backpack of  claim 9 , wherein the asymmetrical flex material is configured to be subjected to repeated bending and release cycles at 50% of a force required to break the asymmetrical flex material without breaking the asymmetrical flex material. 
     
     
         12 . The backpack of  claim 9 , wherein the asymmetrical flex material is configured to be subjected to repeated bending and release cycles at 50% of a force required to break the asymmetrical flex material without breaking the asymmetrical flex material for up to 5,000 flex and release cycles. 
     
     
         13 . The backpack of  claim 9 , comprising a plurality of reinforcement stays. 
     
     
         14 . The backpack of  claim 9 , wherein the flexural modulus of the at least one reinforcement stay in the first direction relative to the second direction is from 1.5:1 to 6:1.