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 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 leg 1 erected on a floor surface, a seat 3 supported above the leg 1 and a suspension support mechanism 5 configured to operatively support the seat 3, in a front-rear direction and in a right-left direction, along a predetermined trajectory by suspending the part of the seat 3 from a part of the leg 1, the suspension support mechanism 5 comprises a inclining function Q configured to downwardly incline the seat 3 so that a tip side in a movement direction of the seat 3 is positioned below a base end side when the seat 3 operates from a reference position_(S) at which the seat 3 can rest by its own weight.

Abstract: Lift-assist systems for adjustable objects are provided, which could include at least one of an enclosed spring and a substantially flat, elongated torsion spring. Suitable substantially flat springs could be configured to twist and untwist up to between 45-135 degrees when the seat or other object is adjusted between stowed and use configurations. In some preferred aspects, the spring could be made from a tempered steel material.

Abstract: A seat guiding apparatus for a chair includes a base, an elastic assembly mounted in the front end of the base and having a torsion spring and a moveable plate abutted against the torsion spring, and a seat assembly provided with a seat and a bracket connected with the seat. The bracket of the seat assembly has a front end connected with the moveable plate and a rear end movably mounted in curved guiding grooves of the base, such that the seat assembly is moveable along the curved guiding grooves relative to the base. As a result, when sitting on the seat, a sitter' back can be guided by the movement of the seat assembly to lean against a backrest of the chair for support.

Abstract: A chair adjustment structure includes a base member, a top cover pivotally connected to the base member, a spring member connected between the base member and the top cover, and a back bracket pivotally connected to the base member and the top cover. Therefore, when the user sits on the seat pad of the chair, the back bracket is forced to pivot the top cover to provide the user with sitting comfort.

Abstract: A tilting fitting device enables a chair seat to be tiltable forwards and backwards against spring force of tilt-resisting springs, the tilting fitting having an upper part that is fastenable to the chair seat and a lower part that is fastenable to a chair base and tiltably connected to the upper part, wherein the tilting resistance is adjustable by adjusting spacing between the tilt-resisting springs and distance of each spring from a respective side of a tilting axis for the upper part. An actuating element is arranged for simultaneous engagement with two support members, an actuating element, along a part of each of its two sides in the element's direction of motion. On movement of the actuating element in the longitudinal direction of the tilting axis, it is adapted to cause rotation of the support members and springs mounted thereon, thereby changing the spacing of the springs.

Abstract: A lock device capable of suppressing a lack of smoothness in an unlocking operation, and of suppressing, in a case a plurality of lock members are operated by a cam member, unevenness in the timing for the plurality of lock members to become engaged in a locking operation. Guide portions of a lower guide include a plurality of cam guide faces that are arranged away from each other in the circumferential direction. A cam includes a plurality of guided faces that respectively abut against the plurality of cam guide faces in a release phase. The guided face in a direction in which the cam is decentered by a biasing force of the lock spring is extended to the release phase side with respect to the other guided faces.

Abstract: The chair comprises an axis X1 that extends right and left and that connects a seat 6 and a supporting body 3 arranged under the seat 6 in a rotatable manner at a front end portion of the seat frame 4, an axis X2 that connects the seat 6 and a backrest 7 in a rotatable manner at a rear side to the axis X1 and an axis X3 that connects the backrest 7 and the supporting body 3 in a rotatable manner, and the seat and the backrest are made to make a rocking movement between an upright posture and a rearward tilted posture with synchronizing the seat and the backrest by adopting an arrangement of a sliding engagement structure to a supporting portion of the axis, and the chair is also provided with a restraining member B1 to restrain a sliding range of the axis X1 variably by directly working the axis X1 to be restrained, an operating member B2 to operate the restraining member B1, a transmitting axis B3 to transmit an operating force of the transmitting member B2 to the restraining member B1 and a click stop mecha

Abstract: A first chair part may be fixed relative to a second chair part by way of a sliding member attached to the first part which slides in a body attached to the second chair part. The chair parts are fixed relative to each other when a pin associated with the body engages in one of several apertures in the sliding member to fix the chair parts. A bent leaf spring may have an end engaging a collar on the pin. The other end of the leaf spring may be pulled to urge the leaf spring to pivot about a fulcrum created by the bend. However, if there is a force trying to move the sliding member with respect to the body (as may result from a spring between the two chair parts), a consequent shear force on the pin may be sufficiently strong to resist the urging of the leaf spring. In such case, the leaf spring will simply bend when its other end is pulled until the force between the body member and slider is relieved.

Abstract: A base manipulation device for an office chair includes a bottom plate having locking slots and pivoted with a chair base which has a rotation plate provided with a pivot plate and a drive plate. An operation bar is pivoted on the pivot plate and has a distal end pressed on the pneumatic bar. A positioning plate is secured on a rod which is moved with the drive plate. When the operation bar is driven to pivot vertically, the pneumatic bar is driven to adjust a height of a seat. When the operation bar is driven to move horizontally, the rotation plate is rotated to move the drive plate which moves the rod which moves the positioning plate to insert into or detach from one locking slot of the bottom plate, thereby achieving a purpose of adjusting an angle of inclination of the seat.

Abstract: A swivel arrangement is provided for a chair having a backrest, a chair seat, a chassis, and a base. The chassis includes a swivel seat mounted to an underside of the chair seat, a first connecting seat, a second connecting seat, a spring seat, a control device, and an adjusting rod. The swivel seat includes a hole and a stop adjacent to the hole. The control device includes a pressing plate engaged with an inner end of the adjusting rod and an operative block with a pressing portion. The first connecting seat, the swivel seat, and the second connecting seat are connected by axle rods.

Abstract: A seat adjustment mechanism for a chair includes a first handle which controls the height of the seat above a surface supporting the chair. A second handle allows the user to selectively lock the seat at a user selected angle relative to the supporting surface. As the seat is tilted into a desired position, the seat adjustment mechanism provides limited horizontal and vertical movement of the seat to maintain the chair in an ergonomically correct position. The mechanism includes a housing or enclosure adapted for connection to a pedestal, and a seat bracket for mounting to the underside of the seat. An intermediate bracket is pivotably mounted to the lower enclosure. One end of the seat mounting bracket is pivotably connected to an end of the intermediate bracket, and the other end of the seat bracket is interconnected with the lower enclosure via a link arrangement.