Chair seat and back structure

Abstract

A chair seat and back structure includes a loop-shaped part with a space encompassed by an inner edge thereof, and an elastic covering part; the loop-shaped part has a curvature and a loop-shaped holding groove near to a circumferential edge thereof; the covering part positioned over the loop-shaped part, in tension and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part; therefore, the covering part will be changed in the shape by the sitter's body curvature, and the sitter's body will touch the chair with increased area.

1 . A chair seat and back structure, comprising 
 a loop-shaped part with a space encompassed by an inner edge thereof; the loop-shaped part having a curvature and a loop-shaped holding groove near to a circumferential edge thereof; and    a covering part secured over the loop-shaped part; the covering part including:    (a) an inner covering sheet, the inner covering sheet being positioned over the loop-shaped part in tension, and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part;    (b) a foam part stuck on the inner covering sheet; and    (c) an outer covering sheet, the outer covering sheet being positioned over the foam and the loop-shaped part in tension, and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part.    
   
   
       2 . The chair seat and back structure as recited in  claim 1 , wherein an elongate insert is tightly fitted into the loop-shaped groove of the loop-shaped part to cover the circumferential edges of both the inner and the outer covering sheets.  
   
   
       3 . A chair seat and back structure, comprising 
 a loop-shaped part with a space encompassed by an inner edge thereof; the loop-shaped part having a curvature and a loop-shaped holding groove near to a circumferential edge thereof; and    a covering part secured over the loop-shaped part; the covering part including:    (a) an inner covering sheet, the inner covering sheet being positioned over the loop-shaped part, in tension and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part; and    (b) an outer covering mesh sheet, the outer covering mesh sheet being positioned over the loop-shaped part, in tension and with a circumferential edge thereof being passed into the loop-shaped holding groove and secured to the loop-shaped part.    
   
   
       4 . The chair seat and back structure as recited in  claim 3 , wherein an elongate insert is tightly fitted into the loop-shaped groove of the loop-shaped part to cover the circumferential edges of both the inner covering sheet and the outer covering mesh sheet.