Patent ID: 7490902

Claim:
A chair ( 1 ), comprising a bottom chair part ( 2 ) having a column ( 3 ), with a seat support ( 4 ) held on the bottom chair part ( 2 ), a seat ( 6 ) connected pivotably to the seat support ( 4 ), and a backrest support ( 5 ) holding a backrest ( 7 ) and connected pivotably to the seat support ( 4 ), wherein movement of the seat ( 6 ) is coupled to movement of the backrest support ( 5 ) by a synchronizing mechanism having at least one spring device ( 10 ) and coupling elements, movement of the coupling elements of the synchronizing mechanism relative to each other can be blocked by a locking device ( 25 ), the locking device ( 25 ) is adjustable between a released position and a locked position, the synchronizing mechanism is located essentially within the column ( 3 ), a column base ( 19 a ) is connected to a lower column part ( 14 a ) of the column ( 3 ) and also to a spring element arranged in the lower column part ( 14 a ) formed by a gas spring ( 32 ), for adjusting seat height, and an upper column part ( 13 a ) that is connected to the seat support ( 4 ) is provided with the at least one spring device located therein, which is supported on a bottom side by a thrust support ( 16 a ) connected to a piston rod of the gas spring ( 32 ), the piston rod of the gas spring ( 32 ) comprises, on a top end thereof, a threaded bolt ( 18 a ) or is connected to a threaded bolt ( 18 a ) and the thrust support ( 16 a ) for the spring has a threaded bore hole ( 17 a ) screwed onto the threaded bolt ( 18 a ) for adjustment of the spring bias of the at least one spring device ( 10 ), and receives force on a toy side from the backrest support ( 7 ), via a plunger ( 12 ), and the upper column part ( 13 a ) extends telescopically at least partially into an inner cavity of the lower column part ( 14 a ).