Chair having a seat whose position is adjustable

Abstract

A chair includes a stand, a support base mounted on the stand, a backrest mounted on the support base, a fixed bracket pivotally mounted on the support base, a movable bracket movably mounted on the fixed bracket, and a seat mounted on the movable bracket to move with the movable bracket. Thus, when the movable bracket is unlocked from the fixed bracket, the movable bracket is movable relative to the fixed bracket so that the seat is movable relative to the stand and the backrest to adjust the position of the seat relative to the stand and the backrest according to a user's requirement, thereby providing a comfortable sensation to the user.

1 . A chair comprising:
 a stand;   a support base mounted on the stand;   a backrest mounted on the support base;   a fixed bracket pivotally mounted on the support base;   a movable bracket movably mounted on the fixed bracket;   a seat mounted on the movable bracket to move with the movable bracket.   
   
   
       2 . The chair in accordance with  claim 1 , wherein:
 the fixed bracket has two downward extending upright sidewalls each formed with an elongated slideway and a plurality of locking grooves each connected to the slideway;   the chair further comprises a control handle pivotally mounted on the movable bracket to move with the movable bracket and having a first end formed with two positioning portions each movable in the slideway of the fixed bracket and each slidably inserted into and detachably locked in one of the locking grooves of the fixed bracket to lock the movable bracket on the fixed bracket temporarily.   
   
   
       3 . The chair in accordance with  claim 2 , wherein the locking grooves of the fixed bracket are equally spaced from each other. 
   
   
       4 . The chair in accordance with  claim 2 , wherein the locking grooves of the fixed bracket are located above the slideway. 
   
   
       5 . The chair in accordance with  claim 2 , wherein the each of the sidewalls of the fixed bracket is pivotally mounted on the support base by a bolt. 
   
   
       6 . The chair in accordance with  claim 2 , wherein each of the positioning portions of the control handle has a substantially L-shaped profile. 
   
   
       7 . The chair in accordance with  claim 2 , wherein the positioning portions of the control handle are directed toward each other. 
   
   
       8 . The chair in accordance with  claim 2 , wherein:
 the control handle is pivotally mounted on the movable bracket by two pivot brackets;   the chair further comprises two torsion springs each biased between the control handle and a respective pivot bracket to pivot the control handle relative to the movable bracket and the fixed bracket and to move each of the positioning portions of the control handle toward one of the locking grooves of the fixed bracket to lock the movable bracket on the fixed bracket at a normal state.   
   
   
       9 . The chair in accordance with  claim 8 , wherein the pivot brackets are secured on a bottom of the movable bracket. 
   
   
       10 . The chair in accordance with  claim 8 , wherein the control handle has a second end formed with a holding portion. 
   
   
       11 . The chair in accordance with  claim 10 , wherein a distance between the holding portion of the control handle and each of the pivot brackets is greater than that between each of the positioning portions of the control handle and each of the pivot brackets to facilitate a user pivoting the control handle. 
   
   
       12 . The chair in accordance with  claim 10 , wherein when the holding portion of the control handle is movable upward, the control handle is pivotable relative to the movable bracket, and each of the positioning portions of the control handle is movable downward to detach from one of the locking grooves of the fixed bracket into the slideway of the fixed bracket and is movable in the slideway of the fixed bracket. 
   
   
       13 . The chair in accordance with  claim 2 , wherein:
 the fixed bracket has a top wall formed with a plurality of screw bores;   the movable bracket is formed with a plurality of guide slots each aligning with a respective screw bore of the fixed bracket;   the chair further comprises a plurality of guide screws each extended through a respective guide slot of the movable bracket and each screwed into a respective screw bore of the fixed bracket.   
   
   
       14 . The chair in accordance with  claim 13 , wherein the screw bores of the fixed bracket is located between the sidewalls. 
   
   
       15 . The chair in accordance with  claim 13 , wherein each of the guide screws is movable in the respective guide slot of the movable bracket when the movable bracket is movable relative to the fixed bracket to guide movement of the movable bracket relative to the fixed bracket. 
   
   
       16 . The chair in accordance with  claim 13 , further comprising a plurality of bushings located between a respective guide screw and a respective guide slot of the movable bracket. 
   
   
       17 . The chair in accordance with  claim 1 , wherein the fixed bracket has a substantially inverted U-shaped cross-sectional profile. 
   
   
       18 . The chair in accordance with  claim 1 , wherein the control handle is located between the movable bracket and the fixed bracket. 
   
   
       19 . The chair in accordance with  claim 1 , wherein the control handle has a substantially U-shaped cross-sectional profile.