Synchronizing mechanism for a chair

Abstract

The invention relates to a synchronizing mechanism for a chair comprising a base part which defines a rotational axis, a backrest support for supporting a backrest and a seat support for supporting a seat. The backrest support is pivotably supported on the base part about a first pivot, and the seat support is pivotably supported on the backrest support about a second pivot. The first pivot of the backrest support is fixed relative to the base part and the second pivot of the seat support is movable relative to the base part. In a basic position, the second pivot is in a lower basic position and the seat support rests against a support structure. In an upper end position, the movable second pivot is moved substantially vertically into an upper end position and the seat support is arranged at a distance to the support structure.

1 . A synchronizing mechanism for a chair, in particular an office chair, comprising
 a base part defining an axis of rotation, a backrest support for holding a backrest and a seat support for holding a seat,   wherein the backrest support is mounted on the base part so as to be pivotable about a first pivot,   wherein the seat support is mounted on the backrest support so as to be pivotable about a second pivot,   wherein the first pivot of the backrest support is fixed relative to the base part and the second pivot of the seat support is movable relative to the base part,   wherein in a basic position, the second pivot is in a lower basic position and the seat support abuts on a support structure, and   wherein in an upper end position, the movable second pivot is moved essentially vertically into an upper end position and the seat support is spaced apart from the support structure.   
     
     
         2 . The synchronizing mechanism according to  claim 1 , wherein the second pivot is fixed relative to the backrest support and is movable essentially vertically upwards with the backrest support. 
     
     
         3 . The synchronizing mechanism according to  claim 1 , wherein in a first intermediate position the second pivot is moved from the lower basic position essentially vertically upwards into a first intermediate position and the seat support is arranged so as to tilt relative to the support structure. 
     
     
         4 . The synchronizing mechanism according to  claim 1 , wherein in the end position the seat support is maximally pivotable relative to the backrest support about the second pivot. 
     
     
         5 . The synchronizing mechanism according to  claim 1 , wherein the base part is arranged as a rigid component. 
     
     
         6 . The synchronizing mechanism according to  claim 1 , wherein, when viewed from a side, the first pivot is arranged in a seat direction behind the axis of rotation and the second pivot is arranged in the seat direction in front of the axis of rotation of the base part. 
     
     
         7 . The synchronizing mechanism according to  claim 1 , wherein the support structure is arranged in front of the axis of rotation of the base part in the seating direction, when viewed from the side. 
     
     
         8 . The synchronizing mechanism according to  claim 7 , wherein the second pivot is arranged between the support structure and the fixed first pivot, when viewed from the side. 
     
     
         9 . The synchronizing mechanism according to  claim 1 , wherein in the basic position a support point of the seat support on the support structure is located in the vertical direction above the first pivot. 
     
     
         10 . The synchronizing mechanism according to  claim 1 , wherein the seat support is designed as a U-shaped profile which, downwardly open, is arranged on the underside of the seat plate. 
     
     
         11 . The synchronizing mechanism according to  claim 1 , wherein the support structure comprises a sliding block which is preferably mounted so as to be rotatable about a third pivot between two tab-like projections of the base part. 
     
     
         12 . The synchronizing mechanism according to  claim 11 , wherein in the basic position and in the first intermediate position the seat support rests with the inner surface of its upper side on the sliding block. 
     
     
         13 . The synchronizing mechanism according to  claim 1 , wherein the backrest support has a slotted guide for the seat support. 
     
     
         14 . The synchronizing mechanism according to  claim 13 , wherein, when viewed from the side, the slotted guide for the seat support comprises a guide slot which is convexly curved upwards and which runs at least partially over an upper edge of the base part. 
     
     
         15 . The synchronizing mechanism according to  claim 1 , wherein the seat support is configured to execute a lateral forward movement from the basic position to the first intermediate position and from the basic position to the end position. 
     
     
         16 . The synchronizing mechanism according to  claim 1 , wherein in a second intermediate position the second pivot is moved from the lower basic position essentially vertically upwards into a second intermediate position in which the seat support is raised so far that it is out of contact with the support structure, so that the seat support with the seat plate can be tilted without guidance about the second pivot. 
     
     
         17 . The synchronizing mechanism according to  claim 15 , wherein in the second intermediate position the seat support has not yet reached its maximum pivotability. 
     
     
         18 . The synchronizing mechanism according to  claim 1 , wherein in a second intermediate position the second pivot is moved from the lower basic position essentially vertically upwards into a second intermediate position in which guide pins operatively connected to the seat support via a slotted guide are raised so far that they are out of contact with the base part, but the seat support has not yet reached its maximum pivotability. 
     
     
         19 . The synchronizing mechanism according to  claim 1 , wherein the fixed first pivot and/or the movable second pivot is/are realized by means of a deformable structure. 
     
     
         20 . A chair, in particular an office chair, with a synchronizing mechanism according to  claim 1 .