A seating arrangement includes a back arrangement movable between upright and reclined positions, a linkage arrangement including a first link member comprising a portion of a seat arrangement, a second link member supported on a base, flexibly resilient front link members extending between forward portions of the first and second link members and being integral with the second link member, and a rigid rear link member extending between rearward portions of the first and second link members including a separate piece from the first or second link members, wherein the rearward portion of the first link member extends laterally in a first plane when the back arrangement is upright, and laterally in a second plane when the back arrangement is reclined, where the second plane is angled with respect to the first plane, and is positioned farther away from the base when the back arrangement is reclined than when upright.

A pivot shaft (10) which is a first shaft member coupled to a supporting member, an inner cylinder (12) which is a second shaft member coupled to a supported member, and an outer cylinder (14) which is a third shaft member are disposed to be approximately coaxial with each other and disposed radially in multiple layers. The pivot shaft (10) and the inner cylinder (12) are coupled to each other through a first rubber-like elastic member (11), and the inner cylinder (12) and the outer cylinder (14) are coupled to each other through a second rubber-like elastic member (13). The total reaction force is increased by restricting the rotation of the outer cylinder (14) by means of an operating pin (19) which is a reaction force adjusting part and thereby adding a reaction force resulting from the second rubber-like elastic member (13) to a base reaction force resulting from the first rubber-like elastic member (11).

The invention relates to a chair (1) comprising a seat (4), a backrest support (2) and a backrest (3), the backrest support (2) being mounted on the seat (4) and the backrest (3) being mounted on the backrest support (2), and the chair (1) being designed such that, in a sitting position, a user can sit on the seat and rest his back against the backrest (3). The chair (1) also has a counter-rest part (5) which differs from the backrest (3), the backrest (3) being tiltably connected to the backrest support (2), such that it can be folded in the direction of the seat (4) from the sitting position into a support position, and the counter-rest part (5) being coupled to the backrest (3) in such a way that the backrest (3), when folding from the sitting position into the support position, aligns the counter-rest part (5) such that the user can support his buttocks on the counter-rest part (5).

The invention relates to a chair (1) comprising a seat (4), a backrest support (2) and a backrest (3), the backrest support (2) being mounted on the seat (4) and the backrest (3) being mounted on the backrest support (2), and the chair (1) being designed such that, in a sitting position, a user can sit on the seat and rest his back against the backrest (3). The chair (1) also has a counter-rest part (5) which differs from the backrest (3), the backrest (3) being tiltably connected to the backrest support (2), such that it can be folded in the direction of the seat (4) from the sitting position into a support position, and the counter-rest part (5) being coupled to the backrest (3) in such a way that the backrest (3), when folding from the sitting position into the support position, aligns the counter-rest part (5) such that the user can support his buttocks on the counter-rest part (5).

A home or office chair is disclosed having a flexible mesh back rest and a full lumbar back support including upper and lower lumbar supports that are located one above the other at the back of the chair to press against the outside of the mesh back rest. The upper and lower lumbar supports are connected to the back of the chair by a bolt so as to move back and forth in first and opposite directions in response to a user seated in the chair moving his back against and away from the flexible mesh back rest. The upper and lower lumbar supports of the full lumbar back support apply continuous pressure through the mesh back rest to provide support for upper and lower lumbar areas of the user's back regardless of whether the user's back is at rest or pressing against the mesh back rest.

A home or office chair is disclosed having a flexible mesh back rest and a full lumbar back support including upper and lower lumbar supports that are located one above the other at the back of the chair to press against the outside of the mesh back rest. The upper and lower lumbar supports are connected to the back of the chair by a bolt so as to move back and forth in first and opposite directions in response to a user seated in the chair moving his back against and away from the flexible mesh back rest. The upper and lower lumbar supports of the full lumbar back support apply continuous pressure through the mesh back rest to provide support for upper and lower lumbar areas of the user's back regardless of whether the user's back is at rest or pressing against the mesh back rest.

In a configuration in which a holder holding a controller is mounted on a seat part with a plate-shaped member, the exposure of the mounting part of the plate-shaped member on which the holder is mounted is eliminated. A seat device includes a pressure sensor measuring a value relating to the seated person's state, a vibration imparting device performing a vibration imparting operation, an ECU controlling the vibration imparting device corresponding to the measurement result of the pressure sensor, a holder holding the ECU, and a mounting bracket fixed to a lower frame such that the holder is mounted on the lower frame of a seat part. The mounting bracket includes a mounting projection on which side wall of the holder is mounted in a predetermined mounting direction. When the side wall is mounted on the mounting projection, the mounting projection is covered with the side wall.

In a configuration in which a holder holding a controller is mounted on a seat part with a plate-shaped member, the exposure of the mounting part of the plate-shaped member on which the holder is mounted is eliminated. A seat device includes a pressure sensor measuring a value relating to the seated person's state, a vibration imparting device performing a vibration imparting operation, an ECU controlling the vibration imparting device corresponding to the measurement result of the pressure sensor, a holder holding the ECU, and a mounting bracket fixed to a lower frame such that the holder is mounted on the lower frame of a seat part. The mounting bracket includes a mounting projection on which side wall of the holder is mounted in a predetermined mounting direction. When the side wall is mounted on the mounting projection, the mounting projection is covered with the side wall.

A chair having a backrest having an upper backrest section and a lumbar section, wherein the lumbar section is provided with a plurality of perforations and is elastically deformable to allow a backward tilting movement of the upper backrest section under a backward thrust applied from a user's back, and wherein the perforations stop the backward tilting movement of the upper backrest section in a position of maximum backward tilt of the upper backrest section.

A chair having a backrest having an upper backrest section and a lumbar section, wherein the lumbar section is provided with a plurality of perforations and is elastically deformable to allow a backward tilting movement of the upper backrest section under a backward thrust applied from a user's back, and wherein the perforations stop the backward tilting movement of the upper backrest section in a position of maximum backward tilt of the upper backrest section.