Patent ID: 6945602
Filing Date: 2005-09-20
Classification: A47C

Abstract:
1. A chair comprising: a base; a deformable seat member positioned above the base and having an occupant-deformable upper surface disposed for engagement with a chair occupant, said seat member being mounted on a seat frame; a back member projecting upwardly from adjacent a rear edge of the seat member; a rigid upright structure connected to said base for vertical pivoting movement about a first substantially horizontal pivot axis which is positioned below said seat member and extends transversely relative thereto, said upright structure including an upright part which projects upwardly adjacent the rear edge of said seat member and which mounts said back member thereon; a pivot structure connected between said seat frame and said upright structure for permitting said seat member to pivot relative to said upright structure about a second substantially horizontal axis which is generally parallel with but displaced upwardly and rearwardly from said first axis, said second axis being positioned at an elevation at or only a small distance below the upper surface of the seat member when the seat member is not deformed by a seated occupant; and a control linkage connected between said base, said seat frame and said upright structure for causing the seat member to tilt relative to the upright structure in one rotational direction about said second axis in response to rearward tilting of said upright structure in the opposite rotational direction about said first axis; said control linkage including an elongate rigid control link which at one end is solely pivotally connected to said base and at the other end is connected to said upright structure for relative pivoting and translating movement therebetween, and a spring unit cooperating between said seat frame and said other end of said control link for permitting the seat frame to rotate relative to said upright structure in said one rotation direction when the upright structure is tilted rearwardly in said opposite rotational direction.