Chair back adjusting mechanism

Abstract

The present invention is about a chair back adjusting mechanism, and relates to the technical field of chairs. The chair back adjusting mechanism includes a chair back, which is movably disposed above a supporting surface of a chair seat and is provided with a connecting base at a side close to a fixed bracket, and the chair back is movably connected to the connecting base; the connecting base is provided with a first sleeve pipe at a side close to the fixed bracket, the fixed bracket is provided with a second sleeve pipe at a side close to the connecting base. The chair back is connected to a chair body by a sliding and elastic telescopic assembly, which reduces the user's feeling of fatigue and effectively relieves fatigue at the waist of sedentary people; and the chair back adjusting mechanism has a simple structure, which reduces the manufacturing cost.

What is claimed is: 
     
         1 . A chair back adjusting mechanism comprising a chair back ( 1 ), characterized in that the chair back ( 1 ) is movably disposed above a supporting surface of a chair seat, and a distance between the chair back ( 1 ) and a fixed bracket ( 4 ) is adjustable; the chair back ( 1 ) is provided with a connecting base ( 3 ) at a side close to the fixed bracket ( 4 ), and the chair back ( 1 ) is movably connected to the connecting base ( 3 ); the connecting base ( 3 ) is provided with a first sleeve pipe ( 31 ) at a side close to the fixed bracket ( 4 ), the fixed bracket ( 4 ) is provided with a second sleeve pipe ( 41 ) at a side close to the connecting base ( 3 ), and the first sleeve pipe ( 31 ) and the second sleeve pipe ( 41 ) are sleeve jointed coaxially and slidably; at least two sets of sliding guide structures are arranged in a circular array between radial directions of the first sleeve pipe ( 31 ) and the second sleeve pipe ( 41 );
 the sliding guide structures comprise guide blocks ( 411 ) and guide slots ( 311 ), the guide blocks ( 411 ) are accommodated within the guide slots ( 311 ) and slide along the guide slots ( 311 ), the guide blocks ( 411 ) are disposed on the second sleeve pipe ( 41 ), and the guide slots ( 311 ) are disposed in the first sleeve pipe ( 31 ); or the guide blocks ( 411 ) are disposed on the first sleeve pipe ( 31 ), the guide slots ( 311 ) are disposed in the second sleeve pipe ( 41 ), the guide slots ( 311 ) are formed integrally with the sleeve pipe, and the guide blocks ( 411 ) are formed integrally with the sleeve pipe or are independently disposed to be detachably connected to the sleeve pipe;   the chair back adjusting mechanism further comprises a locking-up assembly, which is configured to fix the second sleeve pipe ( 41 ) and the first sleeve pipe ( 31 ); and   the chair back adjusting mechanism further comprises an elastic member, which is between axial directions of the second sleeve pipe ( 41 ) and the first sleeve pipe ( 31 ).   
     
     
         2 . The chair back adjusting mechanism according to  claim 1 , characterized in that the first sleeve pipe ( 31 ) is accommodated within the second sleeve pipe ( 41 ), the guide blocks ( 411 ) are detachably connected to a peripheral side of the first sleeve pipe ( 31 ), and an inner wall of the second sleeve pipe ( 41 ) is provided with the guide slots ( 311 ); or the guide blocks ( 411 ) are detachably connected to the inner wall of the second sleeve pipe ( 41 ), and an outer wall of the first sleeve pipe ( 31 ) is provided with the guide slots ( 311 ). 
     
     
         3 . The chair back adjusting mechanism according to  claim 1 , characterized in that the first sleeve pipe ( 31 ) is accommodated within the second sleeve pipe ( 41 ), the guide blocks ( 411 ) are formed integrally with a peripheral side of the first sleeve pipe ( 31 ), and an inner wall of the second sleeve pipe ( 41 ) is provided with the guide slots ( 311 ); or the guide blocks ( 411 ) are formed integrally with the inner wall of the second sleeve pipe ( 41 ), and an outer wall of the first sleeve pipe ( 31 ) is provided with the guide slots ( 311 ). 
     
     
         4 . The chair back adjusting mechanism according to  claim 1 , characterized in that the second sleeve pipe ( 41 ) is accommodated within the first sleeve pipe ( 31 ), the guide blocks ( 411 ) are detachably connected to a peripheral side of the second sleeve pipe ( 41 ), and an inner wall of the first sleeve pipe ( 31 ) is provided with the guide slots ( 311 ); or the guide blocks ( 411 ) are detachably connected to the inner wall of the first sleeve pipe ( 31 ), and an outer wall of the second sleeve pipe ( 41 ) is provided with the guide slots ( 311 ). 
     
     
         5 . The chair back adjusting mechanism according to  claim 1 , characterized in that the second sleeve pipe ( 41 ) is accommodated within the first sleeve pipe ( 31 ), the guide blocks ( 411 ) are formed integrally with a peripheral side of the second sleeve pipe ( 41 ), and an inner wall of the first sleeve pipe ( 31 ) is provided with the guide slots ( 311 ); or the guide blocks ( 411 ) are formed integrally with the inner wall of the first sleeve pipe ( 31 ), and an outer wall of the second sleeve pipe ( 41 ) is provided with the guide slots ( 311 ). 
     
     
         6 . The chair back adjusting mechanism according to  claim 1 , characterized in that the elastic member comprises a spring ( 5 ), which has one end fixedly clamped with the connecting base ( 3 ) and the other end fixedly clamped with a connecting plate ( 6 ); a distance between the connecting plate ( 6 ) and a cover plate ( 8 ) is adjustable so as to adjust a supporting force of the chair back ( 1 ); and the cover plate ( 8 ) is fixedly connected to the fixed bracket ( 4 ). 
     
     
         7 . The chair back adjusting mechanism according to  claim 6 , characterized in that the cover plate ( 8 ) is provided with an adjusting lever ( 7 ), which is rotatably connected to the cover plate ( 8 ); and the connecting plate ( 6 ) is connected to the adjusting lever ( 7 ) through threads. 
     
     
         8 . The chair back adjusting mechanism according to  claim 1 , characterized in that the locking-up assembly comprises a locking-up bolt ( 9 ), which is slidably connected to the second sleeve pipe ( 41 ) or the first sleeve pipe ( 31 ) and extends or retracts along a radial direction; an outer periphery of the first sleeve pipe ( 31 ) or the second sleeve pipe ( 41 ) is axially provided with a plurality of positioning holes ( 312 ) in an array; and the locking-up bolt ( 9 ) is extendable to be inserted in any one of the positioning holes ( 312 ). 
     
     
         9 . The chair back adjusting mechanism according to  claim 1 , characterized in that a bottom end of the fixed bracket ( 4 ) is provided with a lower support plate ( 42 ) that is connected to the chair seat; a bottom surface of the lower support plate ( 42 ) is provided with a clamping slot ( 421 ) that is slidably connected to a sliding rail of the chair seat; and the lower support plate ( 42 ) is provided with a connecting rod ( 422 ) that penetrates through the entire clamping slot ( 421 ). 
     
     
         10 . The chair back adjusting mechanism according to  claim 1 , characterized in that a top end of the first sleeve pipe ( 31 ) is provided with a straight slot, a rabbet of which is internally provided with a cushion pad ( 32 ); the cushion pad ( 32 ) is accommodated in the rabbet at the top end of the first sleeve pipe ( 31 ) and is fixedly connected to an end surface of the first sleeve pipe ( 31 ); an end surface of the second sleeve pipe ( 41 ) at a side close to the first sleeve pipe ( 31 ) is provided with a limiting retainer ring ( 43 ); the limiting retainer ring ( 43 ) is located at a side of the cushion pad ( 32 ) close to the connecting base ( 3 ); and the limiting retainer ring ( 43 ) is detachably connected to the second sleeve pipe ( 41 ).