Abstract: A chair includes: a leg 1; a seat 2; and a front-back support mechanism 4. The front-back support mechanism 4 is provided at a seat receiving part 50 directly supported by the leg 1, and the front-back support mechanism includes: a wavy plate 56 provided to horizontally extend from vertical walls 51 of the seat receiving part 50 and having mound-shaped surfaces 57, 58 each convexly curved upward; and followers 53, 54 provided at front-back support bodies 52 as supported parts and configured to move relative to the mound-shaped surfaces 57, 58 while contacting the mound-shaped surfaces 57, 58. The wavy plate 56 is associated with the followers 53, 54 such that a movement end inclines downward when the seat 2 moves from a neutral position in accordance with a relative movement between the mound-shaped surfaces 57, 58 and the followers 53, 54.

Abstract: A chair comprises: a leg 1 erected on a floor surface; a seat 3 arranged above the leg 1; and a support mechanism 8 interposed between the leg 1 and the seat 3, wherein the support mechanism 8 is arranged below the seat 3 and is configured to movably support the seat 3 along a predetermined trajectory by having an omnidirectional connection unit 72 configured to operably connect in all directions including the front-rear direction and the left-right direction, comprises: a seat inclining function configured to downwardly incline a tip side in a movement direction of the seat 3, and further comprises: a return-force generation mechanism configured to generate, by elevating a center of gravity of the seat 3, a return force in a direction of returning the seat 3 to the reference position.

Abstract: To provide a chair in which the seated person can perceive a comfortable sitting feeling even if sitting for a long time, and furthermore a high work efficiency can stably be maintained, a chair according to the present invention includes a support mechanism 2 interposed between a leg 1 and a seat 3, wherein the support mechanism 2 includes: a seat inclining mechanism Q as a seat inclining function configured to downwardly incline a tip side in an operation direction of the seat 3 when the seat 3 operates from a predetermined reference position (S), and further includes: a return-force generation mechanism configured to generate, in accordance with an amount of movement, 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).

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 flange part 31b is provided on a vertical surface 31a on the plate member PM of the front-rear swing part 3, the flange part 31b has a guide surface 31b1 extending to lateral direction and moving the rolling body 45 in the longitudinal direction, a lateral direction dimension of the guide surface 31b1 is greater than a thickness of the plate member PM, the flange part 31b and the portion of the plate member PM forming the vertical surface 31a around the flange part 31b are integrally formed of metal; and the flange part 31b has a shape that goes around the circumference of the guide hole 34 opened in the vertical surface 31a, and then, the rolling body 45 are provided independently to the left and right, to be able to a roll along the guide surface 31b1.

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.

Abstract: A chair includes: a leg 1; a seat 2; and a front-back support mechanism 4. The front-back support mechanism 4 is provided at a seat receiving part 50 directly supported by the leg 1, and the front-back support mechanism includes: a wavy plate 56 provided to horizontally extend from vertical walls 51 of the seat receiving part 50 and having mound-shaped surfaces 57, 58 each convexly curved upward; and followers 53, 54 provided at front-back support bodies 52 as supported parts and configured to move relative to the mound-shaped surfaces 57, 58 while contacting the mound-shaped surfaces 57, 58. The wavy plate 56 is associated with the followers 53, 54 such that a movement end inclines downward when the seat 2 moves from a neutral position in accordance with a relative movement between the mound-shaped surfaces 57, 58 and the followers 53, 54.

Abstract: [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.

Abstract: 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.

Abstract: A chair according to the present invention includes: a leg 1; a leg support pole 13; a support base 4; a movement mechanism 5 located below a seat 2, the movement mechanism 5 provided with plural movement parts 5A, 5B configured to allow the seat 2 to move in a certain area along a predetermined trajectory in a front-rear and left-right directions between the support base 4 and the seat 2, the movement mechanism 5 being a support mechanism configured to support the seat 2 so that the seat 2 moves in the front-rear direction and left-right directions; and plural cover members 71, 72 arranged corresponding to the plural movement parts 5A, 5B. The plural cover members 71, 72 are configured to move relatively in accordance with movement of the plural movement parts 5A, 5B and cover the support mechanism 5.