Frame for a pull-rod luggage case

Abstract

A frame for a pull-rod luggage case, including pair of pull rods parallel to each other, a pair of castor seats, an upper beam, a lower beam, and a handle; each of the pull rods at least includes an outer rod and an inner rod telescopically positioned in and out of the outer rod; a lower end of each outer rod is connected to a corresponding castor seat; each of two ends of the handle is fixedly connected with an upper end of a corresponding inner rod; outer rods, the upper beam, and the lower beam define a skeleton.

What is claimed is: 
     
         1 . A frame for a pull-rod luggage case, comprising a pair of pull rods parallel to each other, a pair of castor seats, an upper beam, a lower beam, and a handle;
 each of the pull rods at least comprises an outer rod and an inner rod telescopically positioned in and out of an upper end of the outer rod;   a lower end of each outer rod is connected to a corresponding one of the pair of castor seats; each of the castor seats is further connected with a castor;   each of two ends of the upper beam is fixedly connected with an upper circumferential surface of a corresponding outer rod;   two ends of the lower beam are fixedly connected with the pair of castor seats respectively;   each of two ends of the handle is fixedly connected with an upper end of a corresponding inner rod;   outer rods of the pair of pull rods, the upper beam, and the lower beam define a skeleton.   
     
     
         2 . The frame for a pull-rod luggage case of  claim 1 , also comprising a frame; wherein each of the pair of castor seats comprises an outer seat and an inner seat; each outer seat defines outer surfaces of the shell at a corner of the shell between a back surface, a bottom surface and a corresponding side surface of the shell; the inner seat is positioned inside the shell and being fixedly connected with a corresponding outer seat; the lower beam is positioned inside the shell, and each of the two ends of the lower beam is fixedly connected with one side of a corresponding inner seat;
 the upper beam comprises an outer beam and an inner beam; the outer beam is positioned at an edge between the back surface and a top surface of the shell;   each of the two ends of the outer beam sleeves the upper circumferential surface of a corresponding outer rod; the inner beam is positioned inside the shell, and is also fixedly connected with the outer beam.   
     
     
         3 . The frame for a pull-rod luggage case of  claim 2 , wherein the top surface of the shell is provided with a first recess, and the bottom surface of the shell is provided with two second recesses; the first recess accommodates the outer beam; each of the two second recesses accommodates a corresponding outer seat. 
     
     
         4 . The frame for a pull-rod luggage case of  claim 2 , wherein each of the pair of pull rods has an L-shape cross section; each of the pair of pull rods is fixed to inner side walls and inner bottom wall of the shell, and extends to two different directions. 
     
     
         5 . The frame for a pull-rod luggage case of  claim 1 , wherein all the outer rods and inner rods are made by carbon fibers. 
     
     
         6 . The frame for a pull-rod luggage case of  claim 5 , wherein outer surfaces of the outer rods and the inner rods are each coated with nano UV coating. 
     
     
         7 . The frame for a pull-rod luggage case of  claim 1 , wherein the outer rods and inner rods are elliptical cylinders.