Waist support structure of seat back

Abstract

Disclosed is a waist support structure of a seat back. The seat back includes a first frame, a second frame coupled to the first frame, and a net member mounted between the first and second frames. The second frame includes a mounting brace mounted thereto and the mounting brace include a waist support coupling section that is connectable with a waist support. The waist support includes a support portion including a rigid plate and a connection portion. The support portion includes a barrel mounted thereto and extending toward the connection portion. The connection portion includes a projection peg mounted thereto and extending toward the support portion to correspond to the barrel. An elastic element has an end fit to the projection peg of the connection portion and an opposite end fit in the barrel of the support portion so as to interface between the connection portion and the support portion.

I claim: 
     
         1 . A waist support structure of a seat back, wherein the seat back comprises a first frame, a second frame corresponding to and coupled to the first frame, and a net member mounted between the first frame and the second frame, the second frame comprising a mounting brace mounted thereto, the mounting brace comprising a waist support coupling section mounted thereto, the waist support coupling section being connectable with a waist support, wherein the waist support comprises a support portion and a connection portion; the support portion comprises a plate, the support portion comprising at least one barrel mounted thereto and extending toward the connection portion, the connection portion comprising at least one projection peg mounted thereto and extending toward the support portion, the projection peg and the barrel being arranged to correspond to each other, the connection portion and the support portion comprising at least one elastic element supported and interfacing therebetween, the elastic element having an end fit to the projection peg of the connection portion, the elastic element also having an opposite end fit in the barrel of the support portion. 
     
     
         2 . The waist support structure of the seat back according to  claim 1 , wherein the waist support coupling section comprises an insertion rib and an adjustment toothed rack section mounted on the insertion rib, the insertion rib comprising an upper stop section and a lower stop section; the connection portion is provided with a receiving channel facing the waist support coupling section of the second frame, the receiving channel being fit over the insertion rib of the waist support coupling section of the second frame, the receiving channel being provided, at an upper end thereof, with stop blocks, the receiving channel being also provided, at a lower end thereof, with an adjustment block. 
     
     
         3 . The waist support structure of the seat back according to  claim 2 , wherein the upper stop section is in the form of an elastically deformable barb. 
     
     
         4 . The waist support structure of the seat back according to  claim 2 , wherein the receiving channel comprises two C-shaped channel members forming recessed groove facing each other, the receiving channel being provided with two stop blocks respectively located at left and right sides. 
     
     
         5 . The waist support structure of the seat back according to  claim 2 , wherein the stop blocks of the receiving channel are selectively engageable with and thus stopped by the upper stop section and the lower stop section of the second frame the insertion rib; and the adjustment block at the lower end of the receiving channel is engageable with the adjustment toothed rack section of the second frame the waist support coupling section. 
     
     
         6 . The waist support structure of the seat back according to  claim 1 , wherein the at least one barrel mounted to the support portion extending toward the connection portion comprises a plurality of barrels, the barrels each comprising a fastening hole formed therein; and the at least one projection peg mounted to the connection portion and extending toward the support portion comprises a plurality of projection pegs. 
     
     
         7 . The waist support structure of the seat back according to  claim 6 , wherein the plurality of barrels comprises at least two, the barrels being arranged at locations that are respectively on left and right halves and are opposite to each other, the projection pegs comprising at least two, the two projection pegs and the two barrels being arranged to respectively correspond to each other. 
     
     
         8 . The waist support structure of the seat back according to  claim 1 , wherein the barrels each comprise a fastening hole formed therein; the projection pegs has an outside diameter smaller than an inside diameter of the barrels, the connection portion comprising a through hole formed therein to correspond to the fastening hole of the support portion, the through holes extending through the projection peg, whereby a fastening element is received through the through to fix the connection portion to the support portion.