An adjustable chair comprises chair support, backrest, a backrest support mechanism including at least one backrest arm pivotally connected to the support, and a seat having front and rear regions and a seat surface. The chair includes first and second seat support mechanisms with the first mechanism adjustably connecting the front region of the seat and the second mechanism adjustably connecting the rear region. The second seat support mechanism includes at least one seat arm having front and rear arm extensions and connected to the support for pivotal movement about a horizontal axis. The rear arm extension is pivotally connected to the rear region of the seat. A toggle arrangement is pivotally mounted on the chair support and engages the front end section of the at least one seat arm and front end section of the at least one backrest arm.

A chair assembly includes a base assembly, a seat assembly having a pair of side edges and a fore-to-aft extending longitudinal centerline, a back assembly movable between upright and reclined positions, and an arm assembly including an arm base extending from a first location between the side edges to a second location laterally outward of one of the side edges, wherein the arm base extends at an acute angle with respect to the longitudinal centerline and at an upward angle from the first location toward the second location, a support assembly supported by and extending upwardly from the arm base, and an armrest supported by the support assembly that is adjustable to support the armrest between a plurality of selected vertical positions, wherein the arm assembly and back assembly move at a different rate from one another as the back assembly is moved between the upright and reclined positions.

Described are adjustable seats having a lower portion of a back rest attached to a seat frame having an upper frame and a lower frame. A pivot axis is positioned at an upper end of the lower portion of the back rest, and an upper portion of the back rest is pivotally attached to the pivot axis. The location of the pivot axis is configured to be positioned below a person's shoulders when the person is seated in the adjustable seat. The upper portion of the back rest is also pivotally adjustable relative to the lower portion of the back rest. A seat pan having a front portion pivotally coupled to a rear portion can be attached to the upper frame. An actuation mechanism is configured to simultaneously control a vertical height of the upper frame and a rotational position of the front portion of the seat pan.

A chair back assembly includes a back shell member including laterally extending top, bottom and side portions cooperating to define an open space therebetween, where a portion of the back shell member is located in a lumbar region, a cover having a first surface and a second surface opposite the first surface, wherein the cover covers at least a portion of the open space, and a back frame assembly operably supporting the back shell member and movable between upright and reclined positions, wherein the back frame assembly causes the back shell to flex in a fore-to-aft direction as the back frame assembly is moved between the upright and reclined positions independent of an external force being exerted on the back shell member, and where the lumbar portion of the back shell member remains spaced from the back frame as the back frame is moved between the upright and reclined positions.

A chair back assembly includes a back shell member including laterally extending top, bottom and side portions cooperating to define an open space therebetween, where a portion of the back shell member is located in a lumbar region, a cover having a first surface and a second surface opposite the first surface, wherein the cover covers at least a portion of the open space, and a back frame assembly operably supporting the back shell member and movable between upright and reclined positions, wherein the back frame assembly causes the back shell to flex in a fore-to-aft direction as the back frame assembly is moved between the upright and reclined positions independent of an external force being exerted on the back shell member, and where the lumbar portion of the back shell member remains spaced from the back frame as the back frame is moved between the upright and reclined positions.

An adjustable rotary rocking chair having a chair frame assembly A, an adjustment mechanism B, and a support tube assembly C, wherein the adjustment mechanism B is detachably connected with the chair frame assembly A and is connected with the support tube assembly C in an insertion manner. The adjustable rotary rocking chair can swing and rotate, has higher flexibility and adaptability due to the fact that the height of the rocking chair and the height of the support tubes can be automatically adjusted by users, is portable through a folding design, and can be used indoors and outdoors.

A seat and seatback linkage mechanism includes: a pipe, a side bracket assembly, a seat, a seatback and driving source. The side bracket assembly includes a first side bracket and a second side bracket, and the pipe is mounted on the first and second side brackets. The seat is disposed between the first and second side brackets and includes a bottom surface, the bottom surface includes two first connecting portions and two second connecting portions, and the first connecting portions are pivotally connected to the first and second side brackets, respectively. The seatback is disposed between the first and second side brackets and connected to the second connecting portions of the seat, so that the seatback and the seat are drivingly connected to each other. The driving source is connected to one end of the seatback that is adjacent to the pipe to drive the driven end to move.

A seat and seatback linkage mechanism includes: a pipe, a side bracket assembly, a seat, a seatback and driving source. The side bracket assembly includes a first side bracket and a second side bracket, and the pipe is mounted on the first and second side brackets. The seat is disposed between the first and second side brackets and includes a bottom surface, the bottom surface includes two first connecting portions and two second connecting portions, and the first connecting portions are pivotally connected to the first and second side brackets, respectively. The seatback is disposed between the first and second side brackets and connected to the second connecting portions of the seat, so that the seatback and the seat are drivingly connected to each other. The driving source is connected to one end of the seatback that is adjacent to the pipe to drive the driven end to move.

A seating arrangement includes a base, a back arrangement and a seat arrangement each supported by the base, the back arrangement movable between an upright position and reclined position, the seat arrangement including a stop member, a shell supported on the base and forming at least a portion of the seat arrangement, the shell including a first portion and second portion movable relative to the first portion, the shell configured such that a downward force exerted on the first portion by a seated user forces the back arrangement from the reclined position toward the upright position, and a tilt limiter coupled to the base and configured to engage the stop member at both the upright position and the reclined position.

Chairs, seating systems, chair sub-assemblies and sub-systems, and associated methods of assembly and use. Aspects relate to chairs and methods of assembling chairs including chair controls of a relatively compact and effective design with desirable synchronous raising and tilting motions. Aspects also relate to tilt lock assemblies for achieving secure and effective tilt securement. Additional aspects relate to forward and rearward adjustment, or extension and retraction, of a seating assembly of the chair.