A chair that provides movement of a seat about an axis of rotation above the seat plane with the seat having a sensor in communication with a computer system that tracks movement. The seat may be simultaneously pivotable about a second axis of rotation defining a range of motion for the seat about the two axes. An actuation system in communication with the computer system can move the seat to desired positions and/or prevent the seat from being positioned at certain locations within the range of motion. The computer system may also include an application that can promote user movement within the seat and allow movement of the seat to be used for gaming, health monitoring and treatment, activity tracking, and the like. The chair may include a mechanism that has one or more glides operably received in curved structures to provide the movement about the axes.

A chair, comprising, a backrest, a seat coupled with the backrest, a column coupled with the seat, a linkage statically attached to the backrest and rotatably attached below the seat, a leaf spring statically attached at one end and in direct contact with the linkage to provide a resistance to tilting of the backrest relative to the column. A first structure fixed to the column, where a portion of the first structure has an arc shape that includes one or more teeth, and a second structure in contact with the first structure, wherein a portion of the second structure includes one or more teeth. The chair is configured such that, when a weight is applied to the seat, the one or more teeth of the second structure, a pivot point at which the backrest is configured to tilt relative to the column, and the linkage are configured to move together.

A chair, comprising, a backrest, a seat coupled with the backrest, a column coupled with the seat, a linkage statically attached to the backrest and rotatably attached below the seat, a leaf spring statically attached at one end and in direct contact with the linkage to provide a resistance to tilting of the backrest relative to the column, a first structure fixed to the column. A portion of the first structure has an arc shape that includes one or more teeth, and a second structure in contact with the first structure. The chair is configured such that, when a weight is applied to the seat, one or more teeth of the second structure move along the one or more teeth of the first structure to shorten a working length of the leaf spring and provide an increased resistance to tilting of the backrest relative to the column.

A body support structure includes a base, a seat and a backrest, with the backrest connected to the base with a torsion leaf spring. The torsion leaf spring may be configured with a plurality of fingers, and/or one or more flex regions. One or more struts may be connected between the seat or backrest and the base. In another aspect, the seat and/or backrest may be supported with one or more links that provide a counter-intuitive motion. In another aspect, a link may be coupled to a support with a flexible blade.

An item of seating furniture, in particular an office chair, has a seat carrier for a horizontal seat member, and a backrest carrier for a vertical backrest. The backrest carrier is constructed in a substantially U-shaped manner with two vertically orientated U-shaped members and with a horizontal upper U-shaped member. Wherein, along at least one rotation axis which extends below the seat member, a first rotary joint and a second rotary joint are provided for the lateral tilting movability of the backrest with respect to the seat carrier. The first and second rotary joints are arranged spaced apart from each other along the rotation axis.

A reconfigurable apparatus for seating a user and having: a frame; a seat movable relative to the frame between: a) a first position in which the seat resides with no user sitting on the seat; and b) a loaded position; a back rest with a changeable angular orientation relative to the frame; and an adjusting assembly having a plurality of gears that move relative to each other as an incident of the seat moving from the first position into the loaded position to thereby cause an increase in resistance to changing of the angular orientation of the back rest.

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 assembly (1) of a chair or an armchair comprises a seat body (2), a backrest body (6), a locking and adjustment device (4), and a backrest support (10). The backrest support (10) is engaged with an articulated parallelogram that allows the position of the backrest body (6) to be changed while keeping it parallel to itself. The backrest support (10) further comprises spring return means.

A chair for providing support to a user's spine to improve posture and for providing ways for the user to perform exercises. The chair may include a flexible connection that enables a back support to move side to side through a sidebending range of motion of the user. The back support, which may include a flexible chair spine, may be configured to adapt to the curvature of the user's spine when the user is seated in the chair. A seat of the chair may include channels and vents to improve air circulation within the seat.

The present invention discloses a chair reclining adjustment mechanism, including a chassis, a turntable rotatably connected to the chassis by using a rotation shaft, and an elastic resetting device that is disposed between the chassis and the turntable and is configured to always enable the turntable to have a moving trend of rotating towards one side of the rotation shaft, wherein a rotation gap is provided between the turntable and the chassis at the other side of the rotation shaft; the adjustment mechanism further includes a locking member capable of entering or slipping out of the rotation gap, a locking component that always enables the locking member to have a moving trend of entering the rotation gap and an unlocking component configured to pull the locking member to slip out of the rotation gap.