The invention relates to a mechanical assembly (2), said mechanical assembly (2) comprising, in addition to a leaf spring, at least one further spring element, the elastic restoring force of the at least one further spring element and the elastic restoring force of the one or more leaf springs supporting the seat shell (S) with a total restoring force, and/or the mechanical assembly (2) comprising at least two leaf springs and at least two supports, each support being associated with one of the leaf springs, and at least two supports being displaceable beneath the leaf springs by means of an adjustment mechanism and being displaceable on their trajectories by different extents.

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 rotatable chair back includes a lower section attachable to a chair seat, a flexible Y-shaped upper section for supporting a chair back frame, and two rigid supports extending substantially vertically into and between the upper section and the lower section. In use, the substantially vertical supports each serve as an axis of rotation about which the upper section may rotate relative to the lower section.

A chair includes a seat and a backrest connected to a leg assembly. The front part of the seat is mounted on the leg assembly via a pivot link about an axis. The backrest is connected to the seat by a flexible intermediate part fixed to the leg assembly in the vicinity of the pivot of the seat for the purpose of a pivoting movement of the intermediate part by elastic deformation about an axis. The rear part of the seat is supported by the intermediate part, for example with at least one coupling element.

A movable human support structure has a support against which at least a part of a human can be borne in use, a base, and a first motion transmitting assembly acting between the support and the base. The first motion transmitting assembly has at least one link member connecting between the base and the support. The at least one link member is configured to be movable: a) relative to the support around a first axis; and b) relative to the base around a second axis. The first and second axes are non-parallel to each other. The first motion transmitting assembly is configured to guide movement of the support relative to the base in opposite directions in a non-straight path.

A seating arrangement includes a support shell including a seat portion and a chair back portion each configured to support a seated user, the chair seat portion having a front region and a rear region and the chair back portion having an upper region and a lower region, where the rear region of the seat portion is coupled to the lower region of the chair back portion, a control member including a substantially flexible front support and an attachment point, where the front support engages the support shell in the front region of the seat portion and the control member engages the back portion, and a substantially rigid second support attached to the control member at the attachment point, wherein the control member is an integral, one-piece component including multiple flex regions configured to allow the support shell to move between an upright and reclined position.

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.

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.

A chair back that includes a back support, an upright frame, and at least one flex wing. The back support is substantially flexible and has a first side portion and a second side portion. The upright frame is substantially rigid and has a first frame side and a second frame side. The flex wing is located between the first frame side and the first side portion, where the flex wing includes a front portion coupled to the first side portion, a back portion coupled to the first frame side, and a web portion interconnecting the front portion and the back portion. The flex wing flexes during engagement by a user.