Abstract: On an article of furniture, a bearing assembly is disposed between an elongate central structure and a seat, which permits rotation between the seat and the base. A tablet is provided, which is connected to a tablet arm with a first cylindrical member, and the tablet arm is connected to the elongate central structure of the base with a second cylindrical member. The second cylindrical member is disposed around the elongate central structure with a flange at the upper end thereof. The bottom of the seat has a lobed friction bushing disposed such that the flange of the second cylindrical member contacts the lobed friction bushing and frictionally resists rotation of the tablet arm as the seat rotates 360 degrees relative to the base, leading the tablet to follow the seat as it rotates. A lobed friction bushing is also provided.

Abstract: An “invisible” syncro tilt mechanism is provided for chairs. The chair has a seat with a back portion and a seat pan portion and the seat pan portion is connected to the back portion and to a pivotable support structure, and thereby to a base. The mechanism has a generally closed track defined in the seat pan portion. A plunger is attached to a front portion of the pivotable support structure. The plunger is slidably disposed in the track. A spring is disposed in the track which is connected at opposing ends to the plunger and to a front end of the track. The mechanism does not extend or protrude outside of the seat pan. The mechanism provides synchronous movement of the plunger in the track.

Abstract: The invention provides a chair and mechanism to permit occupant swivelling, bouncing, and tilting. The chair mechanism also provides tilt limitation using a keyhole tilt delimiter. The keyhole orientation follows rotation of the chair. A bearing assembly (preferably using race bearings) facilitates simultaneous swivelling and tilting.