Backrest armrest linkage assembly and folding chair frame

Abstract

A backrest armrest linkage assembly and folding chair frame; the backrest armrest linkage assembly includes a backrest bar and a armrest bar, wherein the middle section of the backrest bar is hinged on the rear support shaft behind the chair, and the lower end is constrained in the guide sleeve. The front section of the armrest bar is positioned on the front support shaft in front of the chair through the chute seat, and the rear end section is hinged to the lower section of the backrest bar, which can draw and restrain the swing angle of the backrest bar, and thus constitute a folding chair frame with adjustable backrest.

We claim: 
     
         1 . A backrest armrest linkage assembly comprising a backrest bar and a armrest bar,
 the middle section of the backrest bar is hinged on the rear support shaft behind the chair, and the inclination angle can be adjusted by swinging around the rear support shaft;   the front section of the armrest bar is positioned on the front support shaft in front of the chair through the chute seat, and the rear end is hinged to the lower section of the backrest bar, which can draw and constrain the swing angle of the backrest bar; and   the lower end of the backrest bar is constrained in a guide sleeve, which is riveted to the chair and has a constant relationship with the rear pivot.   
     
     
         2 . A backrest armrest linkage assembly according to  claim 1 , wherein the chute seat is riveted below the armrest bar, and the front end of the transversely penetrating chute has a clip slot that faces upward; and
 the front support shaft in front of the chair transversely passes through the chute, and can slide relative to each other. It can be constrained when sliding to the stopper opening to form a positioning structure.   
     
     
         3 . A backrest armrest linkage assembly according to  claim 1 , wherein a hinge seat is riveted at the hinged joint between the backrest bar and the armrest bar, and the end of the armrest bar is hinged on the protruding hinge seat. 
     
     
         4 . A backrest armrest linkage assembly according to  claim 1 , wherein the guide sleeve has a long groove structure;
 whereby when the backrest bar is at the maximum inclination angle, the lower end section abuts the front section of the guide sleeve, and the width of the long groove allows the lower end of the backrest bar to swing freely in the front and rear directions.   
     
     
         5 . A folding chair frame, including brackets arranged correspondingly or symmetrically on both sides, a front cross-bar group and a rear cross-bar group associated with the brackets on both sides, and any backrest armrest linkage assembly, comprising:
 the bracket includes a front support bar, a rear support bar and a seat cushion bar;   the front and rear support bars are hinged to form a herringbone support   the seat cushion bar is horizontally and correspondingly hinged on the front support bar and slidably positioned on the rear support bar,   an upright support bar is hinged at the front of the seat cushion bar,   the upper end of the upright support bar is provided with a front support shaft, which slides through the chute seat below the armrest bar,   the lower end is hinged with a front sliding sleeve, which is sleeved on the front support bar by means of the front sliding sleeve; and   the middle section of the backrest bar is hinged on the rear support shaft at the upper end of the front support bar, and the guide sleeve is also riveted to the front support bar to maintain a constant relationship with the rear support shaft.   
     
     
         6 . A folding chair frame according to  claim 5 , wherein the front support bar is hinged with the rear support bar and then extends upward for a section;
 the seat cushion bar is slidably positioned on the rear support bar by means of the rear sliding sleeve, and extends backward for a section at the hinged joint of the rear sliding sleeve;   the upper and lower ends of the rear cross-bar group are correspondingly hinged to the end of the extension section of the front support bar and the end of the extension section of the seat cushion bar.   
     
     
         7 . A folding chair frame according to  claim 5 , wherein the lower part of the front support bar is provided with a front limit ring, and the front limit ring is hinged on the same hinge point where the lower end of the front cross bar group is hinged with the front support bar; and the upper end of the front cross bar group is hinged on the same hinge point of the upright support bar and the seat cushion bar. 
     
     
         8 . A folding chair frame according to  claim 5 , wherein the chute seat is also provided with longitudinal grooves; the upper end of the upright support bar can be inserted into it, and the two ends of the front support shaft fixed at the end correspond to the sliding grooves on the left and right sides.