The self-adjustable backrest device supplements a seat surface such that said seat surface is a previously existing one and what is covered by the object of this invention adds a backrest or improves the existing one, for which purpose it comprises a mobile plate on which the user rests, wherein said plate swivels on a horizontal shaft that passes through a first set of hubs connected to the plate, that shaft being associated with a second set of hubs connected to a support that may be the backrest itself of the chair or easy chair on which the self-adjustable backrest is going to be used, in which case it will be referred to as pre-existing backrest, or it may be a fixed backrest which forms part of the device, in which case it will be referred to as backrest of the device. The device may include fixing elements to prevent its movement, such as legs, pegs, or a flap.

The present invention relates to a chair which includes a subframe, a seat element, a back element, a spring mechanism and an adjustment device, wherein the spring mechanism includes a leaf spring which is clamped on one side in the subframe and a support which is movable on a track between the leaf spring and the subframe and wherein the adjustment device includes an adjustment member and a transmission mechanism. In this connection, a movement of the adjustment member is translated into a movement of the support at a transmission ratio of between 1:0.5 and 1:4.

A method for manufacturing a seat cushion receives data of a specific occupant. A seat cushion is designed from the occupant data. The seat cushion is provided with a cellular structure from the occupant data. Another method for manufacturing a seat cushion receives boundary conditions for a seat cushion. Applicable mechanical properties are determined for the boundary conditions of the seat cushion. Applicable thermal properties are determined for the boundary conditions of the seat cushion. A seat cushion is designed with a varying cellular structure to satisfy the applicable mechanical properties and the applicable thermal properties.

A seat comprising: cushioning made from flexible material comprising a blind cavity, an instrumented unit made from flexible material received inside the cavity, this instrumented unit comprising: an oblong housing, this oblong housing comprising sidewalls that extend mainly toward the inside of the instrumented unit from an entrance situated on one of the side faces of the instrumented unit, this entrance being suitable for allowing an electric device to be inserted into the housing, and the electric device received in its entirety inside this housing.

A seat assembly includes a seat with a hip/thigh support, a back support and at least one gap between the hip/thigh support and the back support. A seating pad assembly is positioned removably on the seat and has a foam cushion made at least partly of a viscoelastic foam and having a dimensionally stable woven fabric cover. Pelvic and upper back areas of a person sitting on the seat deform the viscoelastic foam significantly to provide a comfortable support and to define anchors for the seating pad assembly. The outer cover extends between those anchors for effectively supporting and cradling the lumbar back area of the person in the seat.

A method for correcting a massage position and a massage chair for performing the same includes allowing a shoulder height measurement module to measure a shoulder height of a user, allowing a hip bone position prediction module to predict a hip bone position through a preset prediction method by using the shoulder height measured by the shoulder height measurement module, allowing a massage position determination module to determine a plurality of determination massage positions and a plurality of correction massage positions spaced from the determination massage positions by a predetermined distance on the basis of the hip bone position predicted by the hip bone position prediction module, and allowing a massage ball assembly control module to control a massage ball assembly so as to massage the determination massage positions and the correction massage positions determined by the massage position determination module.

A chair includes a seat pan member, a movement support frame, and at least two movement support members operatively connected to the seat pan member and the movement support frame. The at least two movement support members are configured to support the seat pan member in a floating manner for dynamic movement with respect to the movement support frame in at least one degree of freedom in a horizontal seating plane.

A chair includes a seat pan member, a movement support frame, and at least two movement support members operatively connected to the seat pan member and the movement support frame. The at least two movement support members are configured to support the seat pan member in a floating manner for dynamic movement with respect to the movement support frame in at least one degree of freedom in a horizontal seating plane.

A chair including a subframe, a seat element, a back element, a spring mechanism and an adjustment device. The spring mechanism includes a leaf spring, which is clamped on one side in the subframe, and a support, which is movable on a track between the leaf spring and the subframe. The adjustment device includes an adjustment member and a transmission mechanism. A movement of the adjustment member is translated into a movement of the support at a transmission ratio of between 1:0.5 and 1:4.

An ergonomic sitting device comprising one or more rear supports; a pair of shoulder assemblies configured to extend forward from the one or more rear supports, over a user's shoulders; one or more biasing mechanisms configured to urge the pair of shoulder assemblies rearward towards a back of at least one of a chair and a seat.