Synchronizing mechanism

Abstract

A synchronizing mechanism for the correlated movement of the seat and backrest assembly of an office chair has a basic carrier capable of being positioned on the chair upright, a seat carrier and a backrest carrier. The backrest carrier is capable of pivoting about a transverse shaft and is connected directly in an articulated fashion both to the basic carrier and to the rear end area of the seat carrier such that a pivoting movement of the backrest in a rearward direction induces a lowering movement in the rearward area of the seat carrier. The seat carrier is connected in an articulated fashion to the basic carrier such that a horizontal sliding movement towards the rear is superimposed on the lowering movement of the seat carrier. Through the direct linking of the backrest carrier to the basic carrier and the seat carrier, it is possible to simplify the construction.

1 . A synchronizing mechanism for correlating a movement of a seat and a backrest assembly of an office chair, the synchronizing mechanism comprising: 
 a seat carrier having a rear end area;    a first transverse shaft;    a basic carrier capable of being positioned on the office chair upright;    a backrest carrier capable of pivoting about said transverse shaft and connected directly in an articulated fashion to said basic carrier and to said rear end area of said seat carrier such that a pivoting movement of said backrest carrier in a rearward direction will induce a lowering movement in said rear end area of said seat carrier; and    a second transverse shaft;    said seat carrier capable of pivoting about said second transverse shaft and connected directly to said basic carrier in an articulated fashion such that a horizontal sliding movement towards a rear being superimposed during the lowering movement of said seat carrier.    
   
   
       2 . The synchronizing mechanism according to  claim 1 , wherein in a basic position of the synchronizing mechanism, a ratio of a horizontal component of an articulation distance to a vertical component of the articulation distance lies between 0.6 and 1.7.  
   
   
       3 . The synchronizing mechanism according to  claim 1 , wherein in a maximum rearward-pivoted position of the synchronizing mechanism, a ratio of a horizontal component of an articulation distance to a vertical component of the articulation distance lies between 2.8 and 5.8.  
   
   
       4 . The synchronizing mechanism according to  claim 3 , wherein in the maximum rearward-pivoted position, a ratio of a lowering angle of said seat carrier to a pivoting angle of said backrest carrier lies between 1:2.1 and 1:3.0.  
   
   
       5 . The synchronizing mechanism according to  claim 1 , further comprising a rotary sliding articulation, said seat carrier having a front end area connected to said basic carrier through said rotary sliding articulation.  
   
   
       6 . The synchronizing mechanism according to  claim 1:   wherein said seat carrier has a front end area; and further comprising a locking mechanism provided in said front end area of said seat carrier for locking a position of said seat carrier in relation to said basic carrier.    
   
   
       7 . The synchronizing mechanism according to  claim 1 , 
 wherein said seat carrier has a spring counterpart; and    further comprising a spring configuration for pre-tensioning the synchronizing mechanism, said spring configuration containing a leg spring with a leg abutting against said spring counterpart disposed on said seat carrier such that a position of an articulation point, and thus a spring characteristic of said leg spring, being varied in conjunction with the pivoting of said backrest carrier.    
   
   
       8 . The synchronizing mechanism according to  claim 7 , wherein: 
 said basic carrier has an adjustment mechanism with a worm gear for actuating said adjustment mechanism; and    said leg spring having a further leg supported on said adjustment mechanism in said basic carrier.    
   
   
       9 . The synchronizing mechanism according to  claim 1 , wherein said seat carrier is a seat.