A chair can include a chair back, or backrest, that is coupled to a base of a chair above a seat of the chair. A tilt mechanism can attach the backrest to the base. In some embodiments, the tilt mechanism can be configured so that the backrest rotates about multiple pivots as it reclines from an upright position to a reclined position to drive motion of the seat during recline of the backrest.

An elastic seesaw-type tilting mechanism is provided, including: a base support, configured to be connected with a chair base through a chair column; a seat support, being pivotably mounted on the base support and configured to be connected with a seat; a backrest support, being pivotably mounted on the base support and configured to be connected with a backrest; a first elastic mechanism, being connected with the seat support and the backrest support to form an elastic seesaw mechanism; a second elastic mechanism, being connected with the base support and the seat support, the second elastic mechanism and the first elastic mechanism being respectively biased against the seat support in opposite directions. A swivel chair is further provided, including: one of the elastic seesaw-type tilting mechanism as described above, a seat, a backrest, a chair column and a chair base.

Some embodiments relate to a chair including a base, a hub, and a seat frame. The hub is supported by the base and includes first and second side mounts and first and second covers. The first side mount is positioned on a first side of the chair and includes a back portion and a bottom portion. The first cover is coupled to the first side mount to define a first channel with the first side mount. The seat frame includes a first lateral member having a lower portion and an upper portion that is pivotally coupled to the back portion of the first side mount and is configured to angulate relative to the lower portion. The lower portion of the first lateral member is slidably received in the first channel such that two sides and a bottom of the lower portion received within the first channel are substantially hidden.

A motion seat is described that includes a chassis, a seat frame, a seat cushion, a backrest, and a resilient hinge. The seat frame is attached to the chassis and the seat cushion and the backrest are each attached to the seat frame. The resilient hinge formed as a unitary body and may be formed from a resilient polymer. The seat cushion and/or the backrest is pivotably attached to the seat frame with the resilient hinge

A chair is disclosed having a mechanism with a spring unit that permits mutually synchronous deflection between a backrest and a seat over a range between a respective zero position of back and seat inclination and a respective maximum back or seat inclination. Stationary first and second axes of rotation extend through a base support of a carrier unit. A back carrier is articulated on the first axis of rotation, and a third axis of rotation extends through the back carrier. A front of a base plate lies movably on the base support and a rear of the base plate is articulated on the third axis of rotation. The base support has a U-shape with two arms thereof having portions extending upward to engage associated openings in the base plate. When the mechanism is deflected, a relative displacement between the arms and the openings occurs.

The flexible support device is used for chair back tilting, which is installed under a cushion. The device includes a base, two driving members connected to the chair back, a pulling rod crossing the base and a spring disposed in the base. The base is connected to ends of the driving members. Two ends of the pulling rod are separately connected to two free ends of the two driving members. The pulling rod has a frame encompassing the spring. The frame has an action end blocking the spring. When the chair back is pressed to tilt rearward, the driving members are rotated to draw the pulling rod to move toward the chair back, and the action end of the frame is driven to compress the spring so as to make the chair back flexibly supported.

A chair can include a chair back, or backrest, that is coupled to a base of a chair above a seat of the chair. A tilt mechanism can attach the backrest to the base. In some embodiments, the tilt mechanism can be configured so that the backrest rotates about multiple pivots as it reclines from an upright position to a reclined position to drive motion of the seat during recline of the backrest.

A seat tilting mechanism comprising a main body, a seat support, a backrest support and an articulation mechanism comprising a lever, a first portion of which defines along with a first arm, the seat support and the main body a first quadrilateral hinge, and a second portion of which defines alone with a second arm, the backrest support and the main body a second quadrilateral hinge. Interior corner angles and lengths of each side of the first and second quadrilateral hinges are such that a predetermined angular displacement ratio of the backrest support in relation to the seat support is provided. An extension resistance device is mounted between the main body and the first portion to provide resistance to rotation of the lever. A first end of the extension resistance device is rotationally mounted to the lever at a first mounting point, which is located between the midpoint and upper point, and is angularly displaced from a line extending between the midpoint and the upper point.

A chair can include a chair back, or backrest, that is coupled to a base of a chair above a seat of the chair. A tilt mechanism can attach the backrest to the base at spaced apart locations. In some embodiments, the tilt mechanism can be configured so that the backrest rotates about multiple pivots as it reclines from an upright position to a reclined position to drive forward motion of the seat during recline of the backrest.

A chair back assembly includes a back frame having a front surface and a rear surface and including a laterally extending cross member having opposite end portions, a back shell including a front surface, a rear surface positioned in front of the front surface of the back frame, a pair of laterally spaced side portions defining an opening therebetween, and a top portion extending laterally between and connected to the side portions, wherein the side portions are exclusively connected to the cross member at opposite ends of the cross member, wherein the connection between the side portions of the back shell and the end portions of the cross member are the only connections between the side portions of the back shell and the back frame, and a cover extending across the opening and connected to the side portions and the top portion of the back shell.