Folding chair with movable backrest-supporting tubes

Abstract

A folding chair includes two rear legs having a predetermined shortened length and could therefore be collapsed into a rectangular body having a reduced overall length to occupy an even small space. A backrest is supported on two supporting tubes, which have lower insertion sections for inserting into upper bores of the rear legs. Push buttons are mounted in the supporting tubes and are normally pushed outward by elastic elements to engage with holes provided on the supporting tubes and the rear legs and thereby hold them together. When the push buttons are pushed radially inward, the supporting tubes could be detached from or retracted into the rear legs for the folding chair to have an even reduced collapse volume.

What is claimed is:  
     
         1 . A folding chair with movable backrest-supporting tubes, comprising two spaced hollow rear legs having a predetermined shortened length and being connected to each other by means of a first set of intersected and articulated tubes; a seat; a second, a third, and a fourth set of intersected and articulated tubes connected to two lateral sides and a front side of said seat, respectively; and a plurality of connectors provided at four upper and four lower corners of said folding chair to pivotally join said rear legs, said seat, and said four sets of intersected and articulated tubes, such that said folding chair could be collapsed into a rectangular body; said folding chair being characterized in that a backrest thereof is supported on two separate supporting tubes, each of which including a preformed insertion section having at least one elastic element mounted therein to normally elastically project a push button from a wall of said supporting tube, that said supporting tubes are adapted to downward insert into upper inner bores of said shortened hollow rear legs and to stably locate in said rear legs when said push buttons on said two supporting tubes reach at and separately engage with two radial through holes provided near upper ends of said two rear legs, and that said supporting tubes are adapted to separate from said rear legs by pushing said push buttons radially inward to disengage from said rear legs and pulling said supporting tubes from said rear legs.  
     
     
         2 . The folding chair with movable backrest-supporting tubes as claimed in  claim 1 , wherein said at least elastic element for each of said supporting tube includes a coiled main body having two extended arms in the form of a letter V, and said push button being connected to one of said two extended arms to be normally pushed outward to elastically engage with a radial through hole provided on a wall of said insertion section of said supporting tube.  
     
     
         3 . The folding chair with movable backrest-supporting tubes as claimed in  claim 1 , wherein said insertion section of each said supporting tube has reduced diameter for fitly inserting into a corresponding one of said two rear legs.  
     
     
         4 . The folding chair with movable backrest-supporting tubes as claimed in  claim 1 , wherein said insertion sections are integrally extended from said supporting tubes, and each of said supporting tubes being formed with a first axial recess corresponding to a second axial recess provided on each of said rear legs, so that said first and said second axial recesses engage with each other to define a track for said supporting tube to telescopically slide in said rear leg; and wherein said supporting tubes are provided at upper ends with diameter-expanded heads as stoppers to prevent said supporting tubes from being fully inserted into said rear legs.  
     
     
         5 . The folding chair with movable backrest-supporting tubes as claimed in  claim 4 , wherein each of said supporting tubes has a pair of said elastic elements mounted therein to orient toward two opposite directions.  
     
     
         6 . The folding chair with movable backrest-supporting tubes as claimed in  claim 5 , wherein said backrest is pre-connected to and normally supported on said two supporting tubes.