An adjustable back support assembly coupled to the back of a chair in which a user sits with his back spaced from the chair back. The adjustable back support assembly includes a back support that is pivotally connected to the back of the chair by a hinge. The back support is rotatable at the hinge away from the chair back and towards the back of the user to provide support thereto. The back support assembly also includes a gas cylinder having a retractable piston. The gas cylinder is connected between the back support of the adjustable back support assembly and an upstanding rigid chair backing within the back of the chair. When the retractable piston is forced outwardly from the gas cylinder, a linear pushing force is correspondingly generated by the piston to cause the back support to rotate away from the chair back and towards the back of the user.

Office, work and leisure chair and retrofit kit for causing subliminal movements of the person sitting thereon. The chair has a cruciform base (1), freely articulated rollers (4), a gas-spring support (2) and an interface panel (5) resting thereon as a support panel. Mounted on the support panel is a base panel (28) bearing a seat cover (19) with a seat surface and back rest (22). The seat cover is provided and allowed to wobble, resting via a cover panel (27) on a plurality of spring elements (7), which are displaceable radially, or obliquely in relation to the radial direction, or helically from the centre of the base panel to the periphery of the base panel. The spring elements are mechanically, hydraulically, pneumatically or electrically displaceable, so that the wobble distance of the seat cover and the attenuation of the wobble movement are variable.

An ergonomically improved chair in which the user's thoracic region is supported by a narrow and generally flat or moderately convex thoracic cushion in the midrest region of the chairback. The design omits or greatly minimizes support for the user's scapulae and other areas of the back outside the thoracic region, excepting lumbar and cervical support features in some embodiments. The design differs from the prior art at least in that the thoracic cushion is narrow and configured not to complement that user's spinal curvature. By appropriate selection and design, a chair incorporating the invention may comprise a fabric covering portions of the chairback without significantly affecting functionality. Other embodiments include a chairback comprising regions having differing levels of firmness and/or differing cushion height at appropriate regions to promote concentrated support of the user's thoracic region.

The disclosure relates to a lumbar support assembly, wherein the inclination of a mat is controlled by upward and downward movement of a single nut, thereby making it possible to reducing weight and manufacturing cost of the assembly. According to one embodiment of disclosed herein, a lumbar support assembly includes: a mat having opposite sides that are rotatably connected to opposite sides of a seat frame, respectively; a driving unit coupled to the mat, and including a nut that is configured to be moved upward and downward; and a tension unit having first and second sides that are respectively coupled to the first and second sides of the seat frame, and coupled to the nut while surrounding a rear portion of the mat, wherein the nut allows the mat to be moved frontward or rearward by pulling or loosening the tension unit according to direction of movement.

The disclosure herein relates to lumbar support adjustment for a chair. More specifically, the disclosure related to a lumbar support adjustment mechanism that moves forward and aft relative to the user.

A vehicle seating assembly including a lower seatback. An upper seatback is operably coupled to the lower seatback. The upper seatback is pivotally mounted to the lower seatback at a pivot axis. An arcuate back support bar is disposed in the upper seatback and is configured to rotate the upper seatback between forward and rearward positions. The arcuate support bar includes first and second generally linear members and an arcuate intermediate portion disposed between the first and second generally linear members. An articulation assembly operably couples the lower seatback with the upper seatback.

A back cushioning member having a tensile structure to reduce discomfort of a seated person. A lower lumbar support 10 installed in a lower portion of a back frame 111 and an upper lumbar support 20 installed in an upper portion of the lower lumbar support 10 are provided. Having vertically two lumbar supports 10, 20 enables a first support plate 12 of the lower lumbar support 10 to be provided so as to correspond mainly to a pelvis part where the sense of contact is hardly perceived, whereby the back cushioning member 112 having a tensile structure can be provided with a predetermined restoring force at a predetermined applicable elastic strength. Since the pelvis part located at a lower portion of a human body can be supported reliably, prevention of collapse of posture can be facilitated. Since the upper lumbar support 20 corresponds mainly to a lumbar part, by setting the upper lumbar support 20 to provide a softer springiness than the lower lumbar support 10, the sense of contact in the lumbar part is suppressed and the feeling during seating can be improved.

The invention relates to a lumbar support (1) for a chair with a backrest comprising backrest carriers (7) which are pivotable independently of each other, wherein the lumbar support comprises support regions (10a, 10b) which are each mounted on a spring element (2). The spring action of each spring element (2) is individually adjustable. In this arrangement, the spring elements (2) are arranged on a carrier (5), which can be articulated to the backrest carriers (7) of the backrest of the chair, which are pivotable independently of each other. The invention further relates to a chair with a backrest, which is formed from backrest carriers (7) which are pivotable independently of each other and which also comprises the aforementioned lumbar support (1). In this case, the lumbar support (1) is articulated to the backrest carriers (7) which are pivotable independently of each other.

A backrest for an office chair. The backrest has a support structure on which a backrest shell element can be fastened. The support structure is formed with two braces that which are interconnected at upper and lower end regions and that are spaced from each other between the upper and lower end regions. At least sections of the braces are movable relative to one another.

An office-type chair including a back support having a suspension mesh back support and a back support frame. The suspension mesh back support has an integral retaining channel disposed at a peripheral edge thereof, and the back support frame includes a central pair of upright support posts and wedge base for mounting to a chair frame. The back support frame includes a plurality of flexible and spaced support arms extending laterally outward from the upright support posts. The support arms each have a peripheral edge configured for fastenerless attachment in a tensioned state within the suspension mesh retaining channel. An upholstery cover encapsulates the suspension mesh and back support frame. The office chair also includes a lumbar mechanism including a resilient cushion that may be positioned in the space between the suspension mesh and the support frame and adjusted along the vertical extent of the back support by rolling the resilient cushion on the rear of the suspension mesh.