Chair Having A Synchronizing Mechanism

Abstract

The invention relates to a seat comprising a lower frame which is placed on the floor ( 1 ) and on which a synchronous mechanism ( 2 ) is mounted. A horizontal fixed main rotational axle (D 1 ) and a horizontal secondary rotational axle (D 2 ) that can be pivoted about the main rotational axle (D 1 ) are arranged on the synchronous mechanism ( 2 ). Said synchronous mechanism ( 2 ) also comprises a fixed base ( 20 ) which is to be placed on the lower frame ( 1 ) and penetrated by the main rotational axle (D 1 ). A pivotable seat carrier ( 21 ) for fixing the seat element ( 3 ) is arranged above the base ( 20 ) and is penetrated by the secondary rotational axle (D 2 ). First connecting means ( 22 ) are fixed to the main rotational axle (D 1 ) and the secondary rotational axle (D 2 ) in an articulated manner. Second connecting means ( 23 ) are provided opposite the secondary rotational axle (D 2 ) as a connection between the base ( 20 ) and the seat carrier ( 21 ). A backrest ( 4 ) is fixed to the synchronous mechanism ( 2 ), said backrest being pivotable about the fixed main rotational axle (D 1 ) against the resistance of a spring module ( 24 ). The movements of the seat ( 3 ) and the backrest ( 4 ) are mutually synchronised.

1 . A chair having: 
 a) a substructure ( 1 ) positioned on the floor,    b) a synchronizing mechanism ( 2 ) which is positioned on the substructure ( 1 ) and has:    ba) a fixed, horizontally running main rotary spindle (D 1 );    bb) a horizontally running secondary rotary spindle (D 2 ) which can be pivoted about the main rotary spindle (D 1 );    bc) a fixed base ( 20 ) which is intended for positioning on the substructure ( 1 ) and through which the main rotary spindle (D 1 ) extends;    bd) a seat carrier ( 21 ) which is arranged in a pivotable manner above the base ( 20 ), through which the secondary rotary spindle (D 2 ) extends and on which a seat ( 3 ) can be fastened;    be) first connecting means ( 22 ) which are articulated, on the one hand, on the main rotary spindle (D 1 ) and, on the other hand, on the secondary rotary spindle (D 2 );    bf) second connecting means ( 23 ) which are arranged opposite the secondary rotary spindle (D 2 ) as a connection between the base ( 20 ) and the seat carrier ( 21 );    c) a backrest ( 4 ) which is fastened on the synchronizing mechanism ( 2 ) and can be pivoted about the fixed main rotary spindle (D 1 ) counter to the resistance of a spring subassembly ( 24 ), the movements of the seat ( 3 ) and backrest ( 4 ) being synchronized in relation to one another, characterized in that    d) the backrest ( 4 ) has extensions ( 40 ) which are fitted in a self-supporting manner on the first connecting means ( 22 ).    
   
   
       2 . The chair as claimed in  claim 1 , characterized in that 
 a) two extensions ( 40 ) which are spaced apart parallel to one another, and each have a first and a second retaining contour ( 401 , 402 ), are provided on the backrest ( 4 );    b) the first retaining contours ( 401 ) are fitted on the secondary rotary spindle (D 2 ) and partially engage from beneath here around a respective spindle element ( 220 ) of the first connecting means ( 22 ); and    c) the second retaining contours ( 402 ) butt against the first connecting means ( 22 ).    
   
   
       3 . The chair as claimed in at least one of claims  1  and  2 , characterized in that 
 a) in the state in which the backrest ( 4 ) is inclined in the direction of the front seat edge ( 30 ), the first retaining contours ( 401 ) on the extensions ( 40 ) of the backrest ( 4 ) can be fitted beneath the spindle elements ( 220 ) of the first connecting means ( 22 ); and    b) as the backrest ( 4 ) is pivoted back in the direction of the, in principle, vertical use position:    ba) the first retaining contours ( 401 ) grip beneath the spindle elements ( 220 ) in a claw-like manner, on the side which is directed toward the front seat edge ( 30 ), such that they slope upward from beneath; and    bb) the second retaining contours ( 402 ) are forced against the first connecting means ( 22 ) by the torque generated by the weight of the backrest ( 4 ) itself and the increase in this torque as the contact pressure against the backrest ( 4 ) increases.    
   
   
       4 . The chair as claimed in at least one of  claims 1  to  3 , characterized in that 
 a) the first connecting means ( 22 ) are, in principle, two angle components ( 22 ), each angle component ( 22 ) having the, in principle, cylindrical spindle elements ( 220 ) at the end which is associated with the secondary rotary spindle (D 2 );    b) a through-passage ( 221 ) is present in the angle component ( 22 ), in front of the spindle element ( 220 ), and allows the first retaining contour ( 401 ) to be fitted onto the spindle element ( 220 ); and    c) the second retaining contours ( 402 ) on the extensions ( 40 ) of the backrest ( 4 ) are mating angles ( 402 ), each mating angle ( 402 ) being supported on the associated angle component ( 22 ), engaging beneath the latter in the process.    
   
   
       5 . The chair as claimed in at least one of  claims 1  to  4 , characterized in that an accommodating connector ( 25 ) for the adjustable insertion of a carrying arm ( 50 ), which is a constituent part of an armrest ( 5 ), is provided laterally on the synchronizing mechanism ( 2 ) in each case.  
   
   
       6 . The chair as claimed in at least one of  claims 1  to  5 , characterized in that it is possible to change the depth to which the free end of the carrying arm ( 50 ) is pushed into the accommodating connector ( 25 ), as a result of which it is possible to adjust the span between the two armrests ( 5 ) provided on the chair.  
   
   
       7 . The chair as claimed in at least one of  claims 1  to  6 , characterized in that 
 a) the accommodating connector ( 25 ) is designed as a sleeve component ( 25 ) of, in principle, rectangular inner cross section;    b) the free end of the carrying arm ( 50 ) is in the form of a sliding component ( 500 );    c) the sliding component ( 500 ) contains a slot ( 501 ) through which projects the shank ( 510 ) of a clamping screw ( 51 ) which engages in the accommodating connector ( 25 ) and serves for fixing the selected span of the armrests ( 5 ); and    d) the accommodating connectors ( 25 ) extend from the seat carrier ( 21 ).    
   
   
       8 . The chair as claimed in at least one of  claims 1  to  7 , characterized in that the spring subassembly ( 24 ) in the synchronizing mechanism ( 2 ) contains at least one mechanical spring ( 240 ) and a pneumatic spring ( 241 ).  
   
   
       9 . The chair as claimed in at least one of  claims 1  to  8 , characterized in that 
 a) the spring subassembly ( 24 ) in the synchronizing mechanism ( 2 ) contains two helical springs ( 240 ) and a pneumatic spring ( 241 ), the three springs ( 240 , 240 , 241 ) being arranged in parallel;    b) the pneumatic spring ( 241 ) acts, in particular, as a damping member as the backrest ( 4 ) is deflected into the rearwardly inclined position from its approximately vertical zero position; and    c) the prestressing generated by the spring subassembly ( 24 ) can be set by means of an actuating member ( 242 ).    
   
   
       10 . The chair as claimed in at least one of  claims 1  to  9 , characterized in that the synchronizing mechanism ( 2 ) 
 a) has an arresting element ( 26 ) for blocking the free synchronizing movement;    b) has an actuating device ( 27 ) for selecting in a stepwise manner the depth to which the seat ( 3 ) is extended in relation to the seat carrier ( 21 );    c) has a device ( 28 ) for setting a forward inclination of the seat carrier ( 21 ); and    d) on the base ( 20 ), contains vertical opening ( 200 ) for the insertion of the outwardly extending outer tube ( 100 ) of a height-specific pneumatic spring ( 10 ) positioned vertically in the substructure ( 1 ); and    e) has a guide track ( 23 ) as second connecting means ( 23 ) between the base ( 20 ) and the seat carrier ( 21 ), the seat carrier ( 21 ) being displaced within the guide track during the synchronizing movement.    
   
   
       11 . The chair as claimed in at least one of  claims 1  to  10 , characterized in that, in order to secure a backrest ( 4 ) fitted into the synchronizing mechanism ( 2 ), the second retaining contours ( 402 ) on the extensions ( 40 ) of the backrest ( 4 ) are screwed on the angle components ( 22 ).  
   
   
       12 . The chair as claimed in at least one of  claims 1  to  11 , characterized in that 
 a) a preferably elastic cover ( 41 ) is provided for pulling over the backrest ( 4 ) and as the essential constituent part of the latter, the cover being fixed in a releasable manner on a crossmember ( 43 ) of the backrest ( 4 ) by means of a cover holder ( 42 ); and    b) one end of the cover is fastened on a base plate ( 420 ), which is arranged on the crossmember ( 43 ), and a second end of the cover is fastened on a latching plate ( 421 ), which can be fitted onto the base plate ( 420 ).