Abstract: A chair, in particular an office chair, has a seat inclination mechanism. A transverse strut of the seat inclination mechanism forms a spring device and this spring device has at least one torsion element. The seat inclination mechanism further has a basic support on which a backrest support and a seat element support are articulated. The transverse strut of the seat inclination mechanism forms a spring device. The transverse strut extends in the chair transverse direction and wherein the spring device has at least one torsion element, in particular a torsion bar spring. The torsion element, together with the basic support and/or the backrest support and/or the seat element support, is formed integrally, in particular in one piece, from plastic.

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: An apparatus for sitting, including: a keystone assembly which connects various parts of the apparatus; a back that provides support for at least a person's back or shoulders; a floating lumbar support, which provides support for a person's lower back, attached to the keystone assembly; a seat that can adjust between a forward tilted and reclined position; a plurality of rollers, disposed on the keystone assembly, on which the seat rests; a central column, attached to the keystone assembly, on which the seat can spin; and a lower torsion spring connected to the seat and disposed on the keystone assembly allowing controlled movement of the seat.

Abstract: A chair chassis is revealed. The chair chassis includes a seat base, a middle base and an adjustment member. A sliding plate is connected to each side of the seat base. A sliding slot is arranged at a front and a rear end of each sliding plate and a pulley is arranged transversely between two sliding slots. The two pulleys connect to a tilting board. The middle base between the two sliding plates connects to the tilting board and the two sliding plates by the pulley on the front end. A third pulley slides over a slant part of the middle base. The adjustment member includes a rack, a locking piece and a lock adjustment rod for control of movement of the locking piece to be engaged with and separated from the rack. Thus users with various weights can use the same chair chassis and operate the chair chassis easier.

Abstract: An apparatus for sitting, including: a keystone assembly which connects various parts of the apparatus; a back that provides support for at least a person's back or shoulders; a floating lumbar support, which provides support for a person's lower back, attached to the keystone assembly; a seat that can adjust between a forward tilted and reclined position; a plurality of rollers, disposed on the keystone assembly, on which the seat rests; a central column, attached to the keystone assembly, on which the seat can spin; and a lower torsion spring connected to the seat and disposed on the keystone assembly allowing controlled movement of the seat.

Abstract: An apparatus for sitting, including: a keystone assembly which connects various parts of the apparatus; a back that provides support for at least a person's back or shoulders; a floating lumbar support, which provides support for a person's lower back, attached to the keystone assembly; a seat that can adjust between a forward tilted and reclined position; a plurality of rollers, disposed on the keystone assembly, on which the seat rests; a central column, attached to the keystone assembly, on which the seat can spin; and a lower torsion spring connected to the seat and disposed on the keystone assembly allowing controlled movement of the seat.

Abstract: An apparatus for sitting, including: a keystone assembly which connects various parts of the apparatus; a back that provides support for at least a person's back or shoulders; a floating lumbar support, which provides support for a person's lower back, attached to the keystone assembly; a seat that can adjust between a forward tilted and reclined position; a plurality of rollers, disposed on the keystone assembly, on which the seat rests; a central column, attached to the keystone assembly, on which the seat can spin; and a lower torsion spring connected to the seat and disposed on the keystone assembly allowing controlled movement of the seat.

Abstract: A tilt tension mechanism for a chair comprises a gear drive mechanism for driving a torsion bar having a drive shaft, a face gear and an actuator shaft with a pinion gear section. The pinion gear section and face gear have cooperating spiral threads which provide for multi-teeth engagement. An isolator bearing is disposed adjacent to the engagement section between said pinion gear teeth and said face gear teeth to support vertical tooth loads.

Abstract: The present invention relates to a mobile joint (1) for a seating construction, especially a chair, for mounting between a seat device and a base, comprising at least two joint elements (10, 30) which are reciprocally restricted pivoted between two extreme positions to allow tilting movement of the seating construction effected by the users weight displacement, comprising two outer joint elements (10, 30) which are pivoted related with a middle joint element (20), wherein the rotational axis (40, 50) between the two joint elements (10, 30) and the middle joint element (20) is displaced in relation to each other in the horizontal direction, whereby the joint (1) may assume a stable tilting position between the two extreme positions.

Abstract: The stylish task chair includes a base with casters, a mounting plate, a seat frame, a back frame, a pair of springs and a seat and backrest. The frames are formed of steel wire of seven-sixteenth inch diameter. The chair is formed by welding the springs to the seat frame and the mounting plate and by welding the back frame to the mounting plate, the back frame being contiguous with the springs. A seat panel is fastened to the seat frame and a backrest panel is mounted to the back frame. Two horizontally disposed steel wires are welded to the back frame and support armrests. The spring allows the rearward portion of the seat to pivot and the cantilevered back frame allows the backrest to flex, these pivoting and flexing movements being independent of each other. The steel wire offers comfort and an airy open look. Seat and backrest cushions may be connected to the panels.

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 chair has a seat connected to a support leg in an up and down angularly displaceable manner, elastic elements for propping up a rear end of the seat to a higher position, and a mechanism for limiting position of the seat when the seat seats people; the mechanism has an adjustment rod, a gear turnable together with the adjustment rod, an elastic plate for engaging the gear so as to prevent rotation of the gear when the adjustment rod isn't operated, and eccentric cams for holding the seat at desired position when the chair seats people; the cams can turn together with the adjustment rod, and are each formed with a stopping edge having several sections; thus, the depressed position of the seat, i.e. the position when the seat seats people, is decided by the position of the cams, and the seat can move accordingly when the sitter leans forwards.

Abstract: This invention provides a spring assembly for use in a chair tilt control mechanism. The tilt control mechanism is one that can recline and return a backrest for a chair. The spring assembly includes a cylindrical block that has first and second ends and a central bore. A pair of end caps is located at each of the first and second ends of the block. Each end cap has a receiving section that can rotate within the central bore of the block. Each end cap also has a hole extending through it that provides a coupling point for the chair backrest. The spring assembly also includes at least one steel coil spring around the block. The spring has one terminal end coupled to the tilt control mechanism and the other end coupled to one of the end caps. The end caps rotate within the block as the chair backrest is reclined or returned. The force needed to rotate the end caps is a sum of the spring force provided by the spring and the frictional relationship between the block and the end caps.

Abstract: This invention provides a spring assembly for use in a chair tilt control mechanism. The tilt control mechanism is one that can recline and return a backrest for a chair. The spring assembly includes a cylindrical block that has first and second ends and a central bore. A pair of end caps located at each of the first and second ends of the block. Each end cap has a receiving section that can rotate within the central bore of the block. Each end cap also has a hole extending through it that provides a coupling point for the chair backrest. The spring assembly also includes at least one steel coil spring around the block. The spring has one terminal end coupled to the tilt control mechanism and the other end coupled to one of the end caps. The end caps rotate within the block as the chair backrest is reclined or returned. The forced needed to rotate the end caps is a sum of the spring force provided by the spring and the frictional relationship between the block and the end caps.

Abstract: A control for a seat, and a seat in combination with the control and a base, said control comprising an upper and a lower arm pivotally joined, with a flexure extending as a cantilever between them, such that a contactor contacts the flexure, and both permits and limits the tilting movement of the seat.

Abstract: Seating such as chairs and groups of chairs which include a base, a support for an occupant, and a control mounting the support to the base which optionally can enable a rocking motion for the support, and a control for this purpose. A plurality of seating elements and other furniture items can be supported on a single beam.

Abstract: An improved tilt rate control mechanism for a tilt back chair has an adjustable torsion spring, a tilt rate adjustment actuator and an actuator movement mechanism. The torsion spring has an adjustment lever for adjusting the tension on the torsion spring. The tilt rate adjustment actuator is disposed in contact with the adjustment lever such that the movement of the adjustment actuator causes movement of the adjustment lever. The adjustment actuator is moveable between (i) a first actuator position wherein the actuator is proximal to the torsion spring and the adjustment lever is in a minimum tension position, and (ii) a second actuator position wherein the actuator is distal from the torsion spring and the adjustment lever is in a maximum tension position.

Abstract: A tilt assembly comprising a tilt housing, a body support member pivotally attached to said tilt housing about a first horizontal axis and a spring mounted to said tilt housing at a second horizontal axis. The body support member is moveable between a first and second position. The second horizontal axis is adjustably moveable relative to the first horizontal axis. The spring biases said body support member at a first location when the body support member is in the first position and at a second location when the body support member is in the second position, with the second location being a greater distance from the first horizontal axis than the first location. A method for supporting a chair body support member is also provided.

Abstract: Chair with synchronized rocking seat and backrest, comprising: a base support (14), a backrest supporting structure (18), connected to the base support (14) so to rock on a transversal axis (A), and a seat supporting structure (16) rocking on the base support (14) in a synchronized way with respect to the rocking movement of the backrest supporting structure (18). The backrest supporting structure presents, on each side of the chair, a bent metallic rod comprising: an anchoring portion (26) fastened to the base support (14), a riser section (28) which extends upwards, and an elastically deformable area (30) permitting the riser section (28) to rock on the transversal axis (A) with respect to the anchoring portion (26).

Abstract: Tilting seat chair, comprising: a base structure (16) bearing a transverse tilting axis (24), a seat support structure (14), tiltably mounted about the transverse tilting axis (24), an elastic arrangement for opposing the seat tilting motion, and an adjustment device (42) for varying the force opposing the elastic arrangement. The aforesaid elastic arrangement comprises a torsion bar (32) connecting the seat support structure (14) to the base structure (16) in a tilting manner about the transverse tilting axis (24). The torsion bar (32) has at least a first portion (32a) rotatably connected to the seat support structure (14) and at least a second portion (32b) connected to the base structure (16) through the aforesaid adjustment device.

Abstract: Chair with a seat and back tilting in a synchronized way, includes a base structure (14), a seat support structure (18) provided to the base structure (14) about a first transverse axis (22), a back support structure (20) pivoted to the base structure (14) about a second axis (24) parallel to the first, an articulation assembly (48) capable of synchronizing the tilting movements of the seat and the back with each other, an elastic device (32) tending to push the seat (12) and the back (16) towards a forwardly inclined position and tending to oppose rearward tilting of the seat (12) and the back (16), a device to selectively stop the forward tilting travel of the seat and the back in a normal sitting position and in a forwardly inclined position, and a device to immobilize the seat (12) and the back (16) in at least one operating position.

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: Chair with synchronized rocking seat and backrest, comprising:

Abstract: A patient chair has a support pedestal with a pair of front legs, a pair of rear legs, a pair of side members, a rear frame member connecting the two rear legs and a cross member connecting the side members at a location between the front and rear legs. A pair of leaf springs is attached to the underside of the cross member with portions thereof extending forwardly and rearwardly therefrom in a substantially horizontal manner. Each leaf spring includes a U-shaped bight or loop portion at the forwardmost extremity of the leaf spring coupling the forwardly extending portion with a horizontal overlying portion which passes over the cross member and extends rearwardly therefrom terminating in an orthogonally generally upwardly extending back support portion. A seat is fastened to the horizontal overlying portion of each leaf spring for receiving and supporting a chair occupant.

Abstract: A four legged or sled chair having a reclinable seat comprising a frame structure, a seat mounted within the frame structure for pivoting about a transverse torsion bar(s) axis, and elastic stops defining said seat position of maximum rearward pivoting and the position of maximum forward pivoting in relation thereto.