Patent ID: 8100477

Claim:
A synchronizing device ( 6 ) for an office chair, comprising a seat carrier ( 7 ) for carrying a seat ( 1 ) of said office chair, a seat arm ( 8 ) to be connected to a chair column ( 3 ) of said office chair, said seat carrier ( 7 ) being pivotable in relation to said seat arm ( 8 ) about a transverse axis, a backrest arm ( 9 ) connected to said seat arm ( 8 ) and to said seat carrier ( 7 ) such as to be pivotable about a transverse axis, a spring ( 19 ) adapted to counter a synchronized movement of said seat carrier ( 7 ) and backrest arm ( 9 ), a sliding member ( 10 ) extending substantially in a longitudinal direction (D) of said seat ( 1 ) and being articulated to said seat arm ( 8 ), said sliding member ( 10 ) being arranged such that said synchronized movement of said seat carrier ( 7 ) and backrest arm ( 9 ) provides a sliding movement of said seat carrier ( 7 ) in relation to said sliding member ( 10 ) substantially in said longitudinal direction (D) of said seat ( 1 ), a first counter bearing ( 21 ) adapted for support of one end of said spring ( 19 ), said first counter bearing ( 21 ) being retained, during said synchronized movement, in a fixed position in relation to said seat carrier ( 7 ), and a second counter bearing ( 22 ) adapted for support of another end of said spring ( 19 ), said second counter bearing ( 22 ) being adapted to be retained, during said synchronized movement, in a fixed position on said sliding member ( 10 ) such as to counter movement of said first counter bearing towards said second counter bearing in order to provide compression of said spring, characterized in that said sliding member ( 10 ) is provided exteriorly of said spring ( 19 ) and comprises a longitudinally extending contact surface ( 18 ), which is slidable on a corresponding longitudinally extending contact surface ( 16 ) of said seat carrier ( 7 ).