Carrier with Collapsible Wheel Assembly

Abstract

A backpack employs a collapsible stretcher and a collapsible wheel assembly. The backpack may be transformed from a compact mode suitable for portability of the backpack to an extended mode wherein the stretcher is extended. A pair of wheels are inflated so that the wheels at one end contact the terrain and at the other end the stretcher is engaged to the backpack to provide for an efficient transport of an injured individual placed in the stretcher.

1 . A carrier assembly comprising:
 a pair of rail members; and   an axle assembly mounted to an end of said members, said axle assembly comprising:
 a tube; 
 a spring loaded extension axle received in said tube; 
 a journal bearing mounted to said extension axle; 
 a bladder mounted to said journal bearing; and 
 a gas cartridge having a valve and in fluid communication with said bladder, which when said valve is opened, said bladder is inflated to form a wheel rotatable about said extension axle. 
   
     
     
         2 . The carrier assembly of  claim 1  wherein said extension axle is projected transversely and said bladder is projected transversely so that said bladder is projected from said tube and said valve is opened to inflate said bladder. 
     
     
         3 . The carrier assembly of  claim 1  wherein said axle assembly further comprises a second spring loaded axle extension received in a tube at an axially opposite location thereof and mounting a second journal bearing which mounts a second bladder; and a second gas cartridge having a valve in fluid communication with said second bladder wherein when said second valve is open, said second bladder is inflated to form a second wheel rotatable about the extension axle. 
     
     
         4 . The carrier assembly of  claim 1  wherein a flexible carrier connects between said rail members. 
     
     
         5 . The carrier assembly of  claim 1  wherein said gas cartridge is pressurized carbon dioxide. 
     
     
         6 . The carrier assembly of  claim 1  wherein the wheel upon inflation has a width and diameter and the ratio of the diameter to the width is in the range of approximately 0.70 to 2.50. 
     
     
         7 . The carrier assembly of  claim 4  wherein the ratio is approximately 2.00. 
     
     
         8 . The carrier assembly of  claim 1  wherein the bearing has a central axis and a generally cylindrical mounting surface with no radially projecting structure. 
     
     
         9 . A carrier assembly comprising:
 a pair of supports; and   an axle assembly mounted to an end of said supports, said axle assembly comprising:
 a pair of extension axles movable from a storage position to an extended position; 
 a journal bearing mounted to each said extension axle; 
 a bladder mounted to each said journal bearing; and 
 a gas cartridge having a valve and in fluid communication with a said bladder, which when said valve is opened, said bladder is inflated to form a wheel rotatable about a said extension axle. 
   
     
     
         10 . The carrier assembly of  claim 9  wherein when a said extension axle is moved to an extended position, said valve is automatically opened to inflate said bladder.