A synchronous-tilt reclining office chair includes a seat, a backrest interconnected to the seat, and an arrangement providing a synchronous-tilt mechanism that controls synchronous movement of the backrest and seat between a normal non-reclined position and a reclined position. Recline tension provided by the arrangement is a function of a force required to compress at least one tensioning spring mounted below the seat, a weight applied on the seat by a seat occupant, and a location of the weight on the seat relative to front and rear portions of the seat, whereby, as the weight is applied toward the front portion of the seat, recline tension is reduced and, as the weight is applied toward the rear portion of the seat, recline tension is increased.

A seating arrangement includes a rigid back frame, a flexible back shell coupled to the back frame and including a pair of vertical side portions and at least two strap portions extending laterally between the side portions and including a forwardly-facing surface configured to support a back of a seated user, the at least two strap portions including a lowermost strap portion, the lowermost strap portion configured to deflect a first distance when a rearwardly-directed force is exerted on the lowermost strap portion by a seated user, and a lumbar assembly supported from the back frame and configured to support the lumbar region of a back of a seated user, the lumbar assembly configured to deflect a second distance when the rearwardly-directed force is exerted on the lumbar assembly by a seated user, wherein the first distance and the second distance are substantially similar.

A reconfigurable apparatus for sitting and having a seat mounted on a frame and movable under the weight of a sitting user. As an incident of the user sitting, resistance to movement of a back rest component is increased a predetermined amount based upon the user's weight. A manually operable subassembly allows the increased resistance to be changed from the predetermined amount with the user sitting on the seat.

An oscillation mechanism for a seat or a backrest of a chair or of an armchair is provided. The oscillation mechanism has a seat coupling, a backrest coupling, and a functional body made in a single piece of plastic material and consisting of a flexible unit portion, the functional body being elastically deformable by bending for the oscillation of the seat and of the backrest.

A chair includes a base structure, a seat support structure, a back frame comprising a front surface, a rear surface and a forwardly extending bottom portion pivotably connected to the base, a biasing member biasing the back frame from a reclined position toward an upright position, wherein the biasing member is located entirely forward a rearward most edge of the seat support structure, and a back shell comprising a forwardly extending bottom portion connected to the seat support structure, a front surface, a rear surface positioned in front of the front surface of the back frame, a pair of laterally spaced side portions defining an opening therebetween, and a top portion extending laterally between and connected to the side portions, wherein each of the side portions are exclusively connected to the back frame at a first location.

A seat tilting mechanism comprising a main body, a support member rotationally mounted to said main body, and a first extension coil spring mounted between said main body and said support member to provide resistance to rotation of said support member, in which said seat tilting mechanism further comprises a second extension coil spring and an engagement mechanism which engages said second extension coil spring for resistance to rotation of said support member when said first extension coil spring reaches a pre-determined point of extension.

A seating arrangement includes a back frame that includes a top portion, a bottom portion, and a pair of side portions that cooperate to define an opening, wherein at least one of the top portion, the bottom portion and the side portions include a longitudinally extending channel, a back shell having a forwardly facing support surface located within the opening and configured to support a seated user, and an attachment portion that extends about at least a portion of a periphery the support surface, and a cover member extending over the support surface, wherein the cover member is directly attached to the attachment portion of the back shell at an attachment location, and wherein the attachment location and the attachment portion of the back shell are located within the channel and concealed from view.

Disclosed herein is a chair that includes a backrest portion, a seat portion coupled with the backrest portion, a column portion coupled with the seat portion, a linkage coupled with the backrest portion, a leaf spring in direct contact with the linkage, an arc-shaped toothed structure fixed translationally relative to the column portion, and a different toothed structure in contact with the arc-shaped toothed structure. The chair is also configured such that when a weight is applied to the seat portion, a fulcrum point of the leaf spring moves as the different toothed structure moves along the arc-shaped toothed structure to thereby shorten a working length of the leaf spring and provide an increased resistance to tilting of the backrest portion relative to the column portion. A process for assembling the chair and a weight-based tilt-resistance assembly for use with the chair are also described herein.

A support mechanism for mounting a seat part to a foot part of a functional chair having a slide bearing which cooperates with a front section of the seat part, and a pivotable support part which is supported by a cantilever part and which is connected to a region of the seat part that is adjacent to the rear region of a seat surface section of the seat part.

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.