Chair with seat and backrest movable in a synchronized way

Abstract

A chair comprising: a base structure comprising a support, a seat connected to the support via a synchronization mechanism and movable with respect to the base structure between a lowered position and a raised position, and a backrest connected to the synchronization mechanism and movable between an upright position, corresponding to the lowered position of the seat, and a backward-inclined position corresponding to the raised position of the seat, wherein said synchronization mechanism comprises two loop-shaped elastic elements spaced apart in a transverse direction and each comprising a lower portion fixed to a rigid support, an upper portion fixed to the seat, a front elastic portion and an essentially C-shaped rear elastic portion that connect the upper portion to the lower portion, wherein the backrest is fixed to the rear elastic portions of said loop-shaped elastic elements.

1 . A chair comprising:
 a base structure comprising a support;   a seat connected to the support via a synchronization mechanism and movable with respect to the base structure between a lowered position and a raised position; and   a backrest connected to the synchronization mechanism and movable between an upright position corresponding to the lowered position of the seat and a backward inclined position corresponding to the raised position of the seat,   wherein said synchronization mechanism comprises two loop-shaped elastic elements spaced apart in a transverse direction and each comprising a lower portion fixed to the support, an upper portion fixed to the seat, a front elastic portion and a rear elastic portion, which connect the upper portion to the lower portion, wherein the backrest is fixed to the rear elastic portions of said loop-shaped elastic elements.   
     
     
         2 . A chair according to  claim 1 , wherein the backrest comprises two L-shaped lower arms fixed to respective rear elastic portions of said loop-shaped elastic elements. 
     
     
         3 . A chair according to  claim 2 , wherein the rear elastic portion of each of said loop-shaped elastic elements has a rear projection fixed to a respective L-shaped lower arm. 
     
     
         4 . A chair according to  claim 1 , wherein the lower portion of each of said loop-shaped elastic elements comprises two fastening elements fixed to respective side arms of said support. 
     
     
         5 . A chair according to  claim 4 , wherein each of said fastening elements comprises a transverse portion and a longitudinal portion, which are coupled, respectively, with a transverse portion and with a longitudinal portion of the respective side arm. 
     
     
         6 . A chair according to  claim 1 , wherein the upper portion of each of said loop-shaped elastic elements has the shape of a longitudinal rectilinear beam fixed to a corresponding longitudinal rib of the seat. 
     
     
         7 . A chair according to  claim 1 , wherein each of said loop-shaped elastic elements is made from a single piece of molded plastic material. 
     
     
         8 . A chair according to  claim 1 , further comprising a limit stop device operatively interposed between said support and said seat, said limit stop device comprising an upright projecting upwardly from said support and having a slot engaged by a transverse pin fixed to said seat. 
     
     
         9 . A chair according to  claim 1 , further comprising a locking device comprising a housing fixed to the seat, a locking pin movable relative to the housing between a locking position and an unlocking position and cooperating with a fixed locking seat, the locking device further comprising a control device connected to said locking pin via a flexible cable.