Motion mechanism for a chair and chair

A motion mechanism for a chair, the motion mechanism being configured to effect a coordinated movement of a chair seat and chair back of the chair, wherein a seating surface of the chair seat extends essentially in a front-rear direction and a left-right direction of the chair, wherein the chair back is arranged at a rear side of the chair seat, the motion mechanism comprising:

• a mechanism configured to support the chair seat and to couple the chair seat to a chair base assembly;
• a first back support configured to couple the chair back to the mechanism, wherein a first end of the first back support is coupled via a first rotary connection to the mechanism, wherein a second end of the first back support is configured for coupling to the chair back;
• and
• a second back support configured to couple the chair back to the mechanism, wherein a first end of the second back support is coupled via a second rotary connection to the mechanism, wherein a second end of the second back support is configured for coupling to the chair back;
• a first sliding connection coupling the chair seat to the chair back, wherein the first sliding connection is arranged at a left side of the chair seat and chair back, and
• a second sliding connection coupling the chair seat to the chair back, wherein the second sliding connection is arranged at a right side of the chair seat and chair back;
• wherein an axis of rotation of the first rotary connection extends in the front-rear direction and an axis of rotation of the second rotary connection extends in the front-rear direction, and wherein the second end of the first back support comprises a first flexible connection for coupling to the chair back, and wherein the second end of the second back support comprises a second flexible connection for coupling to the chair back.

A chair, comprising:

• a chair base assembly;
• a chair seat;
• a chair back;
• and
• a motion mechanism to support the chair seat and to couple the chair seat to the chair base assembly, the motion mechanism comprising
• a first back support configured to couple the chair back to the mechanism, wherein a first end of the first back support is coupled via a first rotary connection to the mechanism, wherein a second end of the first back support comprises a first sliding connection for coupling to the chair back;
• and
• a second back support configured to couple the chair back to the mechanism, wherein a first end of the second back support is coupled via a second rotary connection to the mechanism, wherein a second end of the second back support comprises a second sliding connection for coupling to the chair back;
• wherein an axis of rotation of the first rotary connection extends in a front-rear direction and an axis of rotation of the second rotary connection extends in the front-rear direction;
• wherein the motion mechanism is attached to the chair base assembly, the chair seat being attached to the mechanism of the motion mechanism, and the chair back being attached to the first and second back supports of the motion mechanism.