Patent ID: 7770973

Claim:
A chair comprising: a seat, a base support, a backrest, a base-seat pivoting mechanism for mounting the seat on the base support so as to be pivotable about a first pivoting axis, a backrest-seat pivoting mechanism for mounting the backrest on the seat so as to be pivotable about a second pivoting axis separated by a distance from the first pivoting axis, and a coupling system which couples the backrest to the seat, the coupling system including a locking mechanism for adjusting and then setting a distance between the first pivoting axis and the second pivoting axis so as to set a depth of the seat, and a coupling mechanism by which a pivoting movement of the seat relative to the base support about the first pivoting axis causes a pivoting movement of the backrest relative to the seat about the second pivoting axis with a specified synchronous relationship between the degree of pivoting of the seat and the inclination of the backrest.