Chair Backrest that is Assembled and Disassembled Easily and Quickly Without Needing Aid of a Hand Tool

Abstract

A chair backrest includes a support frame having an inner periphery provided with a support portion which has an upper edge provided with a plurality of locking blocks, and a backrest cushion having a periphery provided with an elastic snapping portion which is snapped onto the support portion of the support frame and retained by the locking blocks of the support frame. Thus, the backrest cushion is mounted on and detached from the support frame by forcing and retracting the snapping portion of the backrest cushion, so that the chair backrest is assembled and disassembled easily and quickly without needing aid of any hand tool, thereby facilitating the user assembling and disassembling the chair backrest, and thereby facilitating the user replacing the backrest cushion.

1 . A chair backrest, comprising:
 a support frame having an inner periphery provided with a support portion which has an upper edge provided with a plurality of locking blocks;   a backrest cushion having a periphery provided with an elastic snapping portion which is snapped onto the support portion of the support frame and retained by the locking blocks of the support frame.   
   
   
       2 . The chair backrest in accordance with  claim 1 , wherein
 the support portion of the support frame has an upper end and a lower end each provided with a locking groove;   the support portion of the support frame has a right side and a left side each provided with a locking face.   
   
   
       3 . The chair backrest in accordance with  claim 1 , wherein the snapping portion of the backrest cushion is compressible and retractable inwardly and elastically. 
   
   
       4 . The chair backrest in accordance with  claim 3 , wherein the snapping portion of the backrest cushion functions as a locking bar. 
   
   
       5 . The chair backrest in accordance with  claim 1 , wherein the support frame has a lower portion having a middle portion provided with a mounting recess located at an outer side of the support portion of the support frame for mounting a retaining block which abuts the snapping portion of the backrest cushion to clamp the snapping portion of the backrest cushion between the retaining block and the support portion of the support frame. 
   
   
       6 . The chair backrest in accordance with  claim 5 , wherein the retaining block has an inner side having a bottom provided with a retaining groove aligning with the respective locking groove of the support portion of the support frame to clamp the snapping portion of the backrest cushion between the retaining groove of the retaining block and the respective locking groove of the support portion of the support frame. 
   
   
       7 . The chair backrest in accordance with  claim 6 , wherein the retaining groove of the retaining block has a substantially semi-circular shape. 
   
   
       8 . The chair backrest in accordance with  claim 6 , wherein the retaining groove of the retaining block is substantially arc-shaped. 
   
   
       9 . The chair backrest in accordance with  claim 5 , wherein the retaining block is secured in the mounting recess by at least one locking screw. 
   
   
       10 . The chair backrest in accordance with  claim 1 , wherein the snapping portion of the backrest cushion is formed by an elastic metallic hard bar having a bent shape. 
   
   
       11 . The chair backrest in accordance with  claim 2 , wherein the snapping portion of the backrest cushion is clamped between the locking grooves, the locking faces and the locking blocks of the support portion of the support frame, so that the backrest cushion is locked onto the support frame. 
   
   
       12 . The chair backrest in accordance with  claim 1 , wherein the locking blocks are formed on the upper edge of an upper end, a right side and a left side of the support portion of the support frame. 
   
   
       13 . The chair backrest in accordance with  claim 1 , wherein each of the locking blocks of the support portion of the support frame has an inner face provided with a barb-shaped tapered face. 
   
   
       14 . The chair backrest in accordance with  claim 1 , wherein the backrest cushion is a net-shaped body with a substantially arc-shaped profile. 
   
   
       15 . The chair backrest in accordance with  claim 1 , wherein the locking groove of the support portion of the support frame has a substantially semi-circular shape.