Sturdy, Compact, Collapsible Camping Chair with a Central Tube Connector

Abstract

A collapsible chair includes upper tubes, leg tubes, a tube connector and a seat back. The connector has four tubes bent in U shapes. Two bent tubes are welded to each other at the bottoms of the U shapes, and another two bent tubes are inverted and welded to each other at the tops of the inverted U shapes. The arms of the four U shapes are welded to each other. Upper holes are formed by ends of the first bent tubes, and lower holes are formed by ends of the second bent tubes. Lower ends of the upper tubes are inserted into the upper holes, and upper ends of the leg tubes are inserted into the lower holes. Upper ends of the upper tubes fit into tube receptacles in the seat back. The two back upper tubes are bent and are longer than the two straight front upper tubes.

1 . A collapsible chair comprising:
 upper tubes with lower ends and seat ends, wherein the lower ends have circular cross sections;   leg tubes with upper ends;   a seat back with tube receptacles;   two first short tubes that are bent in U shapes and that are welded to each other at the bottoms of the U shapes, wherein four upper holes with circular circumferences are formed at ends of the first tubes; and   two second short tubes that are bent in inverted U shapes and that are welded to each other at the tops of the inverted U shapes, wherein four lower holes with circular circumferences are formed at ends of the second tubes, wherein the first tubes have arms of the U shapes that are welded to arms of the U shapes of the second tubes, wherein the lower ends of the upper tubes are detachably connected to the first tubes by being inserted into the upper holes, wherein the upper ends of the leg tubes are detachably connected to the second tubes by being inserted into the lower holes, wherein the seat ends of the upper tubes are detachably connected to the tube receptacles, and wherein no part of the upper tubes other than the lower ends and the seat ends contacts any part of the collapsible chair.   
     
     
         2 . The collapsible chair of  claim 1 , wherein the upper tubes consist of two tubes of a first length and two tubes of a second length, and wherein the first length is longer than the second length. 
     
     
         3 . The collapsible chair of  claim 2 , wherein each of the two tubes of the first length is bent, and wherein neither of the two tubes of the second length is bent. 
     
     
         4 . The collapsible chair of  claim 2 , wherein each of the upper tubes of the first length has a lower section, a middle section and an upper section, wherein the lower end of each upper tube of the first length is disposed on the lower section of the upper tube, wherein each lower section is curved, and wherein each middle section and each upper section is straight. 
     
     
         5 . The collapsible chair of  claim 1 , wherein the first tubes are welded to the second tubes at only four locations. 
     
     
         6 . The collapsible chair of  claim 1 , wherein each of the upper tubes is comprised of detachable sections. 
     
     
         7 . The collapsible chair of  claim 1 , wherein the circular cross section of each of the lower ends is dimensioned to fit snugly into the circular circumference of a corresponding upper hole. 
     
     
         8 . The collapsible chair of  claim 1 , wherein the upper tubes consist of four tubes, and wherein the seat ends fit into the tube receptacles at four corners of the seat back. 
     
     
         9 . The collapsible chair of  claim 1 , wherein the seat back is made of fabric. 
     
     
         10 . The collapsible chair of  claim 1 , further comprising:
 an elastic cord that passes through one of the first short bent tubes and into one of the upper tubes.   
     
     
         11 . A collapsible chair comprising:
 upper tubes with lower ends and seat ends, wherein the lower ends have circular cross sections;   leg tubes with upper ends;   a seat back with tube receptacles;   a central tube connector with two first tubes bent in U shapes and two second tubes bent in inverted U shapes, wherein the first tubes are welded to each other at the bottoms of the U shapes, wherein the second tubes are welded to each other at the tops of the inverted U shapes, wherein four upper holes are formed at ends of the first tubes, wherein four lower holes are formed at ends of the second tubes, wherein arms of the U shapes of the first tubes are welded to arms of the inverted U shapes of the second tubes, wherein the lower ends of the upper tubes are detachably connected to the first tubes by being inserted into the upper holes, wherein the upper ends of the leg tubes are detachably connected to the second tubes by being inserted into the lower holes, wherein the seat ends of the upper tubes are detachably connected to the tube receptacles, and wherein no part of the upper tubes other than the lower ends and the seat ends contacts any part of the collapsible chair.   
     
     
         12 . The collapsible chair of  claim 11 , further comprising:
 an elastic cord that passes through one of the upper tubes and into one of the upper holes.   
     
     
         13 . The collapsible chair of  claim 11 , wherein the four arms of the U shapes of the first tubes are welded to the four arms of the inverted U shapes of the second tubes at four locations. 
     
     
         14 . The collapsible chair of  claim 11 , wherein the upper tubes include two tubes of a first length and two tubes of a second length, and wherein the first length is longer than the second length. 
     
     
         15 . The collapsible chair of  claim 14 , wherein each of the two tubes of the first length is bent, and wherein neither of the two tubes of the second length is bent. 
     
     
         16 . The collapsible chair of  claim 14 , wherein each of the upper tubes of the first length has a lower section, a middle section and an upper section, wherein the lower end of each upper tube of the first length is disposed on the lower section of the upper tube, wherein each lower section is bent, and wherein each middle section and each upper section is not bent. 
     
     
         17 . A method comprising:
 forming upper tubes with lower ends and seat ends, wherein the upper tubes are formed in sections, and wherein the lower ends have circular cross sections;   forming leg tubes with upper ends;   bending first tubes and second tubes into U shapes;   welding two first tubes to each other at the bottoms of the U shapes, wherein upper holes with circular circumferences are disposed at ends of the first tubes, and wherein the circular cross sections of the lower ends are dimensioned to fit snugly into the circular circumferences of the upper holes;   welding two second tubes to each other at the bottoms of the U shapes and inverting the two welded second tubes such that four lower holes with circular circumferences are formed at ends of the second tubes, and wherein the upper ends of the leg tubes are dimensioned to fit snugly into the lower holes;   welding arms of the U shapes of the first tubes to arms of the U shapes of the inverted second tubes; and   making a seat back with tube receptacles disposed at locations on the seat back so as to fit over the seat ends of the upper tubes.   
     
     
         18 . The method of  claim 17 , further comprising:
 pulling an elastic cord through one of the first tubes and into one of the upper tubes.   
     
     
         19 . The method of  claim 17 , wherein the first tubes are welded to the second tubes at only four locations. 
     
     
         20 . The method of  claim 17 , further comprising:
 placing the upper tubes, the leg tubes, the first tubes, the second tubes and the seat back in a bag that is less than one foot long.   
     
     
         21 - 24 . (canceled)