Abstract: In the chair, a space between swinging surfaces facing each other can be appropriately unseen. The chair includes swinging surfaces (rolling surfaces) (312a) and (322a) facing each other and has a configuration in which the swinging surfaces (312a) and (322a) swings with respect to each other in directions of 360 degrees including front-rear and left-right directions. In such a chair, an elastic member (33) is arranged to be positioned between the swinging surfaces (312a) and (322a) at least in the vicinity of outer peripheral edges (312z) and (322z), and a stretchable sheet material (60) is provided between the outer peripheral edges (312z) and (322z) to conceal a gap between the swinging surfaces (312a) and (322a) facing each other, the gap including the elastic member (33).

Abstract: The chair has a simple structure in which a seat can follow a free movement of a seated person in front-rear, left-right, and diagonal directions, a burden from an operation by which the seated person balances his or her load can also be reduced, and a movement by which the seated person changes his or her posture stably and continuously can be suitably supported. The chair includes a movement mechanism 3 that causes an upper base unit (31) to swing in a direction of 360 degrees with respect to a lower base unit (32), and a seat 1 attached to the upper base unit (31). The chair further includes a damper mechanism (DM) that may operate by following a movement in a direction of 360 degrees, as a mechanism separate from the movement mechanism (3), at a position connecting the upper base unit (31) and the lower base unit (32).

Abstract: Provided is an unprecedented chair in which a space between swinging surfaces facing each other can be appropriately hidden. The chair includes swinging surfaces (rolling surfaces) 312a and 322a facing each other, and has a configuration in which the swinging surfaces 312a and 322a swings with respect to each other in directions of 360 degrees including front-rear and left-right directions. In such a chair, an elastic member 33 is arranged to be positioned between the swinging surfaces 312a and 322a at least in the vicinity of outer peripheral edges 312z and 322z, and a stretchable sheet material 60 is provided between the outer peripheral edges 312z and 322z to conceal a gap between the swinging surfaces 312a and 322a facing each other, the gap including the elastic member 33.

Abstract: Provided is an unprecedented chair in which movement of a seat by using a rolling surface can be smoothly performed. The chair includes an upper base unit 31 and a lower base unit 32 facing each other, and a seat 1 that is provided in the upper base unit 31 and swings when the upper base unit 31 rolls with respect to the lower base unit 32, and the upper base unit 31, which is at least one of the upper base unit 31 and the lower base unit 32, includes a rolling surface 312a being curved. In the chair, a region having a different curvature exists in a part of the rolling surface 312a, and an elastic member 33 is interposed between the region having the different curvature and a corresponding region of an opposing surface.

Abstract: The chair has a simple structure in which a seat can follow a free movement of a seated person in front-rear, left-right, and diagonal directions, a burden from an operation by which the seated person balances his or her load can also be reduced, and a movement by which the seated person changes his or her posture stably and continuously can be suitably supported. The chair includes a movement mechanism 3 that causes an upper base unit 31 to swing in a direction of 360 degrees with respect to a lower base unit 32, and a seat 1 attached to the upper base unit 31. The chair further includes a damper mechanism DM that may operate by following a movement in a direction of 360 degrees, as a mechanism separate from the movement mechanism 3, at a position connecting the upper base unit 31 and the lower base unit 32.

Abstract: To realize a noble, useful seat with a simple structure designed to follow a natural movement of a seated person in front-rear and left-right directions and to support appropriately a movement of the person continuously changing its posture while the person balances a load. The seat includes the elastic support layer 3 and upper and lower base units 4 and 5 arranged to sandwich the elastic support layer 3. The upper base unit 4 includes the rolling surface 42e bulging toward the lower base unit 5 thereabove via the elastic support layer 3, is rollable in a 360° direction from the tilt reference position IRP in receiving a load of the seated person, and has a moving distal end side tilting more downward as a distance from the position IRP increases, and is configured to move while compressing the elastic support layer 3 by the rolling surface.

Abstract: A chair includes a leg 1, a seat 5 including a pressure receiving surface PS, a backrest 6, and a support mechanism SM. The seat 5 can move in the front-rear or left-right direction along a predetermined trajectory and to downwardly incline a tip side of the seat 5 in a movement direction in accordance with a movement of the seat 5 from a predetermined reference position (S). The support mechanism SM includes a return-force generation unit configured to generate, in accordance with an amount of movement, a return force in a direction in which the seat 5 moved from the reference position (S) in the front-rear or left-right direction is returned to the reference position (S), and movably supports the backrest 6 in the left-right direction together with a movement of the seat 5 in the left-right direction.

Abstract: A chair is realized which takes specific measures to suppress movement of a seat in a front-rear direction when the seat swings in the front-rear and the left-right directions with respect to a support base. For the purpose, the chair wherein a seat 5 swings in the front-rear and left-right directions with respect to a support base 2, the chair is configured such that swinging of the seat 5 in front-rear direction with respect to the support base 2 is capable of being suppressed at one or a plurality of predetermined positions, or arbitrary position via operation of operation member 152.

Abstract: A chair according to the present invention has a reference position P located midway in a front-back direction in a movable range of a seat 2. The chair includes a return force generation mechanism 4 configured to generate a return force in a direction to return the seat 2 moved from the reference position P at least in the front-back direction to the reference position P. The return force generation mechanism 4 includes an elastic member 40 configured to increase the return force in the direction to return the seat to the reference position P as the amount of movement of the seat from the reference position P increases.

Abstract: A chair includes a leg 1, a seat 5 including a pressure receiving surface PS, a backrest 6, and a support mechanism SM. The seat 5 can move in the front-rear or left-right direction along a predetermined trajectory and to downwardly incline a tip side of the seat 5 in a movement direction in accordance with a movement of the seat 5 from a predetermined reference position (S). The support mechanism SM includes a return-force generation unit configured to generate, in accordance with an amount of movement, a return force in a direction in which the seat 5 moved from the reference position (S) in the front-rear or left-right direction is returned to the reference position (S), and movably supports the backrest 6 in the left-right direction together with a movement of the seat 5 in the left-right direction.

Abstract: To realize a noble, useful seat with a simple structure designed to follow a natural movement of a seated person in front-rear and left-right directions and to support appropriately a movement of the person continuously changing its posture while the person balances a load. The seat includes the elastic support layer 3 and upper and lower base units 4 and 5 arranged to sandwich the elastic support layer 3. The upper base unit 4 includes the rolling surface 42e bulging toward the lower base unit 5 thereabove via the elastic support layer 3, is rollable in a 360° direction from the tilt reference position IRP in receiving a load of the seated person, and has a moving distal end side tilting more downward as a distance from the position IRP increases, and is configured to move while compressing the elastic support layer 3 by the rolling surface.

Abstract: [Problem] Provided is a chair capable of changing an operation of a movable part between allowed and suppressed states, without causing an up-down movement of a seat or without requiring a complicated structure relying on a back. [Solution] For that purpose, a weight-receiving part 50, the height position of which changes due to a person sitting on a seat surface, is provided on a seat 5, the change of the height position is mechanically transmitted to a control mechanism 8X configured to control an operation of a front-rear swing part 3 being the movable part, and the control mechanism 8X changes an operation of the front-rear swing part-3 being the movable part between allowed and suppressed states.

Abstract: In view of various movement of a seated person, when giving the left-right swinging operation to the seat in the non-conventional aspect, a chair configured such that the back can perform a new movement suitable for the left-right movement of the seat and return to the predetermined position when the seated person leaves a seat, is realized. For the purpose, a back 6 is arranged behind a seat 5, and the back 6 has an operation mechanism 6M turning-movably supporting the load received from a seated person in a left-right direction in a front view, and when the load is applied, at least a part of guide part 65a, 66a of the operation mechanism 6M is separated and the back moves freely, and when the applied load is removed, the back automatically returns to the neutral position along the guide part 65a, 66a.