Backrest adjusting mechanism and chair using same

Abstract

This invention is a backrest adjusting mechanism and a chair using the same and relates to the technical field of chairs. The backrest adjusting mechanism has a backrest, and the backrest is movably arranged above a support surface of a chair body, and a distance between the backrest and a backrest support plate of the chair body is adjustable; the backrest is provided with a connecting base on a side close to the backrest support plate of the chair body. The backrest adjusting mechanism has at least one set of sliding assembly, wherein the sliding assembly is configured to connect the connecting base and the backrest support plate of the chair body.

What is claimed is: 
     
         1 . A backrest adjusting mechanism, comprising a backrest ( 1 ), wherein the backrest ( 1 ) is movably arranged above a support surface of a chair body ( 3 ), and a distance between the backrest ( 1 ) and a backrest support plate of the chair body ( 3 ) is adjustable; the backrest ( 1 ) is provided with a connecting base ( 2 ) on a side close to the backrest support plate of the chair body ( 3 ), and the backrest ( 1 ) is movably connected with the connecting base ( 2 );
 the backrest adjusting mechanism further comprises at least one set of sliding assembly, wherein the sliding assembly is configured to connect the connecting base ( 2 ) and the backrest support plate of the chair body ( 3 ), the sliding assembly comprises a sliding block ( 11 ) and a sliding rail ( 12 ), the sliding block ( 11 ) is slidably connected with the sliding rail ( 12 ), the sliding block ( 11 ) is fixedly connected with the connecting base ( 2 ), the sliding rail ( 12 ) is fixedly connected with the chair body ( 3 ), and the sliding rail ( 12 ) is provided with an anti-off component for limiting the sliding block from falling off;   the backrest adjusting mechanism further comprises an elastic member, arranged between the connecting base ( 2 ) and the backrest support plate of the chair body ( 3 ).   
     
     
         2 . The backrest adjusting mechanism according to  claim 1 , wherein the elastic member comprises a spring ( 5 ) having an end fixedly engaged with the connecting base ( 2 ) and an end fixedly engaged with an engaging block ( 6 ), a distance between the engaging block ( 6 ) and a cover plate ( 8 ) is adjustable for adjusting a support force of the backrest ( 1 ), and the cover plate ( 8 ) and the chair body ( 3 ) are fixedly connected. 
     
     
         3 . The backrest adjusting mechanism according to  claim 2 , wherein an adjusting rod ( 7 ) is arranged on the cover plate ( 8 ) and rotatably connected with the cover plate ( 8 ), and the engaging block ( 6 ) is in threaded connection with the adjusting rod ( 7 ). 
     
     
         4 . The backrest adjusting mechanism according to  claim 1 , further comprising a locking mechanism, the locking mechanism being configured to fix the connecting base ( 2 ) to keep a fixed distance from the chair body ( 3 ). 
     
     
         5 . A chair, comprising the backrest adjusting mechanism according to  claim 1 , the backrest ( 1 ) being slidably connected to the connecting base ( 2 ), the backrest ( 1 ) moving vertically up and down along the connecting base ( 2 ), the connecting base ( 2 ) being provided with a height adjusting assembly, the height adjusting assembly being configured to adjust a height of the backrest ( 1 ). 
     
     
         6 . The backrest adjusting mechanism according to  claim 1 , wherein the height adjusting assembly comprises a swing rod ( 22 ) and a limit rod ( 221 ), a fan-shaped groove ( 211 ) is formed in a side of the connecting base ( 2 ) away from the backrest ( 1 ), and the swing rod ( 22 ) is received in the fan-shaped groove ( 22 ); one end of the swing rod ( 22 ) is hinged with the connecting base ( 2 ), and a torsion spring is arranged at the hinged position to keep the swing rod ( 22 ) in a vertical state;
 a groove ( 101 ) is formed in a side of the backrest ( 1 ) close to the connecting base ( 2 ), a plurality of oblique tooth grooves ( 102 ) are arranged in an array in a vertical direction in the groove ( 101 ), a tooth groove direction of the oblique tooth grooves ( 102 ) faces downward, and the limit rod ( 221 ) is fixed on an end of the swing rod ( 22 ) away from the hinged position, and extends through the connecting base ( 2 ) to be inserted into one said oblique tooth groove ( 102 ).   
     
     
         7 . A chair, comprising the backrest adjusting mechanism according to  claim 1 , the backrest ( 1 ) being hinged with the connecting base ( 2 ) through a pivot, the backrest ( 1 ) swinging in a vertical plane along the connecting base ( 2 ) within a set swing angle range. 
     
     
         8 . A chair, comprising the backrest adjusting mechanism according to  claim 1 , the backrest ( 1 ) being provided with a rotating shaft along a vertical direction, the backrest ( 1 ) and the connecting base ( 2 ) being hinged through the rotating shaft.