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 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 chair includes a support mechanism 2 interposed between a leg 1 and a seat 3, wherein the support mechanism 2 is arranged below the seat 3, is configured to each individually and movably support the seat 3, at least at two locations in a front-rear direction and two locations in a left-right direction, along a predetermined trajectory, and the support mechanism 2 includes: a seat inclining mechanism Q or a seat inclining function configured to downwardly incline a tip side in a movement direction of the seat 3 in accordance with movement of the seat 3, and further includes: a center-of-gravity movement mechanism P or a return-force generation mechanism configured to generate a return force in a direction of returning the seat 3 having moved from a reference position (S) in a front-rear or left-right direction, to the reference position (S) by using a center-of-gravity movement.

A chair includes a support mechanism 2 interposed between a leg 1 and a seat 3, wherein the support mechanism 2 is arranged below the seat 3, is configured to each individually and movably support the seat 3, at least at two locations in a front-rear direction and two locations in a left-right direction, along a predetermined trajectory, and the support mechanism 2 includes: a seat inclining mechanism Q or a seat inclining function configured to downwardly incline a tip side in a movement direction of the seat 3 in accordance with movement of the seat 3, and further includes: a center-of-gravity movement mechanism P or a return-force generation mechanism configured to generate a return force in a direction of returning the seat 3 having moved from a reference position (S) in a front-rear or left-right direction, to the reference position (S) by using a center-of-gravity movement.

The invention relates to a self-adjusting joint (11) which is designed to receive an end of a chair leg of an active dynamic chair, comprising a hollow inner cylinder (12) that comprises an upper and lower end-face edge (12o, 12u) and a hollow outer cylinder (13) that is arranged around the exterior of the inner cylinder (12) and has an upper and lower end-face edge (130, 13u), each of which is offset relative to the upper and lower end-face edge (12o, 12u) of the inner cylinder (12) in the axial direction (A), and a first compression spring section (11a) that consists of a plurality of cylinder bodies or cylinders (15a) which surround the inner cylinder (12) and between which a respective elastomer section (14a) is arranged so as to connect the cylinder bodies or cylinders, and a second compression spring section (11b) that is arranged at a distance from the first compression spring section in the axial direction (A) and consists of a plurality of cylinder bodies (15b) or cylinders which surround the inner cylinder (12) and between which a respective elastomer section (14b) is arranged so as to connect the cylinder bodies or cylinders.

The invention relates to a self-adjusting joint (11) which is designed to receive an end of a chair leg of an active dynamic chair, comprising a hollow inner cylinder (12) that comprises an upper and lower end-face edge (12o, 12u) and a hollow outer cylinder (13) that is arranged around the exterior of the inner cylinder (12) and has an upper and lower end-face edge (130, 13u), each of which is offset relative to the upper and lower end-face edge (12o, 12u) of the inner cylinder (12) in the axial direction (A), and a first compression spring section (11a) that consists of a plurality of cylinder bodies or cylinders (15a) which surround the inner cylinder (12) and between which a respective elastomer section (14a) is arranged so as to connect the cylinder bodies or cylinders, and a second compression spring section (11b) that is arranged at a distance from the first compression spring section in the axial direction (A) and consists of a plurality of cylinder bodies (15b) or cylinders which surround the inner cylinder (12) and between which a respective elastomer section (14b) is arranged so as to connect the cylinder bodies or cylinders.

A chair according to the present invention is a chair comprising a leg 1 arranged on a floor surface, a leg support pole 13 erected from the leg 1, a support base 4 fixed at an upper end of the leg support pole 13, a seat 2 arranged above the support base 4 and a support mechanism 5 interposed between the support base 4 and the seat 2 and configured to support the seat 2 movably in a front-rear direction and a left-right direction. Additionally, in the support mechanism 5, a left-right support part 51 is attached to the support base 4 movably in a left-right direction, a front-rear part 52 is attached to the left-right support part 51 movably in a front-rear direction, the seat 2 is attached to the front-rear support part 51, and the support base 4 has an arm attachment part 6.

A chair according to the present invention is a chair comprising a leg 1 arranged on a floor surface, a leg support pole 13 erected from the leg 1, a support base 4 fixed at an upper end of the leg support pole 13, a seat 2 arranged above the support base 4 and a support mechanism 5 interposed between the support base 4 and the seat 2 and configured to support the seat 2 movably in a front-rear direction and a left-right direction. Additionally, in the support mechanism 5, a left-right support part 51 is attached to the support base 4 movably in a left-right direction, a front-rear part 52 is attached to the left-right support part 51 movably in a front-rear direction, the seat 2 is attached to the front-rear support part 51, and the support base 4 has an arm attachment part 6.

A chair back assembly includes a back frame having a front surface and a rear surface and including a laterally extending cross member having opposite end portions, a back shell including 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 the side portions are exclusively connected to the cross member at opposite ends of the cross member, wherein the connection between the side portions of the back shell and the end portions of the cross member are the only connections between the side portions of the back shell and the back frame, and a cover extending across the opening and connected to the side portions and the top portion of the back shell.

[Problem] The present invention provides a chair and a cover member of the chair that include a cover which can appropriately maintain the appearance of the chair while preventing a sitting person from touching a movement mechanism moving below a seat at the time of movement of the seat or a backrest. [Means for Solving the Problem] A chair according to the present invention is provided with cover members 71, 72 for covering a movement mechanism 5 to support a seat movably at least one direction of front-rear direction and left-right direction, and is configured so that the cover members 71, 72 include a plurality of through-holes 71x, 72x arranged lengthwise and breadthwise.