Telescopic handle for luggage cart

Abstract

A telescopic handle for luggage cart includes a simplified locating mechanism for conveniently locking tubes of the telescopic handle in place when the tubes have been pulled to a fully extended position. The tubes of the telescopic handle could be extended and telescoped relative to one another without the need of a pushbutton mechanism. Instead, the telescopic handle employs elastically retractable steel balls to enable automatic locking of the extended tubes of the telescopic handle in place, so that the handle could be more conveniently operated.

What is claimed is:  
     
         1 . A telescopic handle for luggage cart, comprising a lower frame for firmly connected to a trunk or a luggage seat of a luggage cart, an upper frame, and two laterally symmetrical middle tubes slidably extended between said lower frame and said upper frame; said lower frame including left and right square lower tubes, said upper frame including left and right square upper tubes and a handle grip connected to upper ends of said left and said right upper tubes; said telescopic handle being characterized in that: 
 each of said left and said right lower tubes of said lower frame has a hollow stop plug defining a central hole connected to an upper end of said lower tube for said middle tube to extend therethrough;    each of said left and said right upper tubes of said upper frame has a locating piece connected to a lower end of said upper tube, said locating piece including a radial hole for accommodating a tension spring and a steel ball therein, said steel ball being normally pushed outward by said tension spring;    each of said middle tubes has a hollow stop plug defining a central hole connected to an upper end of said middle tube for said upper tube to extend therethrough, and a locating piece connected to a lower end of said middle tube; said locating piece including a radial hole for accommodating a tension spring and a steel ball therein, said steel ball being normally pushed outward by said tension spring;    each of said lower tubes of said lower frame is provided near the upper end with a locating hole adapted to engage with said steel ball in said locating piece connected to the lower end of said middle tube and thereby automatically locks said middle tube in place when said middle tube is pulled to a fully extended position relative to said lower tube; and    each of said middle tubes is provided near the upper end with a locating hole adapted to engage with said steel ball in said locating piece connected to the lower end of said upper tube and thereby locks said upper tube in place when said upper tube is pulled to a fully extended position relative to said middle tube.    
     
     
         2 . The telescopic handle for luggage cart as claimed in  claim 1 , wherein each of said hollow stop plugs connected to the upper end of said middle tube has an inner diameter smaller than an outer diameter of said locating piece connected to the lower end of said upper tube, and each of said hollow stop plugs connected to the upper end of said lower tube has an inner diameter smaller than an outer diameter of said locating piece connected to the lower end of said middle tube.  
     
     
         3 . The telescopic handle for luggage cart as claimed in  claim 1 , wherein each of said locating pieces connected to the lower end of said upper tube has an outer diameter similar to an inner diameter of said middle tube, and each of said locating pieces connected to the lower end of said middle tube has an outer diameter similar to an inner diameter of said lower tube.  
     
     
         4 . A telescopic handle for luggage cart, comprising a lower frame for firmly connected to a trunk or a luggage seat of a luggage cart, and an upper frame, said lower frame including left and right square lower tubes, and said upper frame including left and right square upper tubes and a handle grip connected to upper ends of said left and said right upper tubes; said telescopic handle being characterized in that: 
 each of said left and said right lower tubes of said lower frame has a hollow stop plug defining a central hole connected to an upper end of said lower tube for said upper tube to extend therethrough;    each of said left and said right upper tubes of said upper frame has a locating piece connected to a lower end of said upper tube, said locating piece including a radial hole for accommodating a tension spring and a steel ball therein, said steel ball being normally pushed outward by said tension spring; and    each of said lower tubes of said lower frame is provided near the upper end with a locating hole adapted to engage with said steel ball in said locating piece connected to the lower end of said upper tube and thereby automatically locks said upper tube in place when said upper tube is pulled to a fully extended position relative to said lower tube.    
     
     
         5 . The telescopic handle for luggage cart as claimed in  claim 4 , wherein each of said hollow stop plugs connected to the upper end of said lower tube has an inner diameter smaller than an outer diameter of said locating piece connected to the lower end of said upper tube.  
     
     
         6 . The telescopic handle for luggage cart as claimed in  claim 4 , wherein each of said locating pieces connected to the lower end of said upper tube has an outer diameter similar to an inner diameter of said lower tube.