Chair with a backrest adjustment mechanism

Abstract

A chair with a backrest adjustment mechanism includes a chair, a back support board, and a driving mechanism. The chair has a back portion and a seat portion and formed a space for accommodating an occupant. The back support board is movably mounted in front of the back portion. The driving mechanism is operatively mounted between the back support board and the back portion, and capable of moving the back support board forward to reduce a seat depth of the chair for accommodating shorter occupant, and moving the back support board backward to enlarge the seat depth of the chair for accommodating taller occupant. By manipulating the driving mechanism of the present invention, both taller and shorter occupants should be able to find a seat depth to accommodate their upper leg length, so as to help occupants maintain proper back support, distributing their weight evenly across the seat portion.

What is claimed is: 
     
         1 . A chair with a backrest adjustment mechanism, including:
 a chair having a back portion and a seat portion and formed a space for accommodating an occupant sitting therein;   a back support board movably mounted in front of the back portion; and   a driving mechanism operatively mounted between the back support board and the back portion, capable of moving the back support board forward to reduce a seat depth of the chair for accommodating shorter occupant, and moving the back support board backward to enlarge the seat depth of the chair for accommodating taller occupant.   
     
     
         2 . The chair with a backrest adjustment mechanism according to  claim 1 , wherein the back portion and the seat portion are formed integrally. 
     
     
         3 . The chair with a backrest adjustment mechanism according to Claim  1 , wherein the driving mechanism includes a linkage having at least one end pivoted on the back support board and at least another end pivoted on a sliding mount, wherein the sliding mount is capable of sliding and positioning along a surface of the back portion of the chair. 
     
     
         4 . The chair with a backrest adjustment mechanism according to  claim 3 , wherein the linkage includes a linking rod which has one end pivoted to a lower end of the back support board and another end pivoted to the sliding mount. 
     
     
         5 . The chair with a backrest adjustment mechanism according to  claim 3 , wherein the sliding mount has a rear extending end protruded through the back portion and accessible at a rear surface of the back portion. 
     
     
         6 . The chair with a backrest adjustment mechanism according to  claim 3 , wherein the back portion is formed with a guiding slot for guiding the sliding mount to move, along the back portion of the chair. 
     
     
         7 . The chair with a backrest adjustment mechanism according to  claim 1 , in the chair further includes a foot-side portion extending from the seat portion. 
     
     
         8 . The chair with a backrest adjustment mechanism according to  claim 7 , wherein the foot-side portion is formed integrally with the seat portion. 
     
     
         9 . The chair with a backrest adjustment mechanism according to  claim 7 , wherein the foot-side portion is formed with a plurality of slots for selectively engaging a foot step in a variety of heights according to the size of occupant. 
     
     
         10 . The chair with a backrest adjustment mechanism according to  claim 7 , wherein the chair has a foot step detachably mounted in front of the foot-side portion and capable of positioning in a variety of heights according to the size of occupant. 
     
     
         11 . chair with a backrest adjustment mechanism according to  claim 1 , wherein the chair has a pair of armrests extending forward. 
     
     
         12 . The chair with a backrest adjustment mechanism according to  claim 11 , wherein the armrests is detachably connected with a food tray. 
     
     
         13 . chair with a backrest adjustment mechanism according to  claim 1 , wherein the chair has a pair of sliding bushings for sliding along a support rack and lockable at a variety of heights above ground so as to be use as a high chair. 
     
     
         14 . The chair with a backrest adjustment mechanism according to  claim 1 , wherein the support rack includes a front rack, a rear rack, and a pair of joints lockably and pivotally connected the front rack and the rear rack.