Abstract: A folding collapsible chair includes a seat ring and folding legs with a back rest fabric installed over the seat ring. The seat ring has four positioning pieces that have downward facing sheath tubes; each sheath tube has a locking structure. The folding legs include four support rods and two horizontal bars. The four support rods correspond with the four positioning pieces. Two diagonal support rods form a unit, fixed together with a horizontal bar to form one body. Two of the aforementioned units, each of which incorporates two support rods with a horizontal bar, are cross-hinged together so that they can pull together when folded up for storage with the seat ring. The aforementioned seat ring is linked together into a locking structure with the top ends of the four support rods by means of the positioning pieces' sheath tubes.

Abstract: A hanging chair that includes an upper frame member that is connectable to an external support structure, a lower frame member, and a plurality of upright supports that each extend from the upper frame member to the lower frame member. The plurality of upright supports are pivotally moveable between a collapsed position and an expanded position.

Abstract: A suspension chair includes a first and second back support portion having first and second suspension elements extending in first and second substantially perpendicular directions respectively. The first and second suspension elements are tensioned so as to provide first and second normal biasing forces to the first and second body support portions. In one embodiment, the chair includes a fixed support defining an upper portion and a pivotable side support. A fabric layer covers at least a portion of the fixed support and a front surface of the side support. Various furniture arrangements and modular furniture kits incorporating one or more chairs, desks and/or tables are provided.

Abstract: A chair having a fixed support structure including two side uprights, a backrest having two side portions, and a pair of elastic joints connecting said side portions of the backrest to said side uprights, wherein each of said elastic joints comprises: a bushing fixed to a respective side upright, a helical spring having a longitudinal axis, the helical spring having an upper end resting against a front wall of the bushing, a compression member resting against a lower end of the spring, an upper attachment fixed to a corresponding side portion of the backrest, and a rigid connecting rod having an upper end and a lower end.

Abstract: A chair having a fixed support structure including two side uprights, a backrest having two side portions, and a pair of elastic joints connecting said side portions of the backrest to said side uprights, wherein each of said elastic joints comprises: a bushing fixed to a respective side upright, a helical spring having a longitudinal axis, the helical spring having an upper end resting against a front wall of the bushing, a compression member resting against a lower end of the spring, an upper attachment fixed to a corresponding side portion of the backrest, and a rigid connecting rod having an upper end and a lower end.

Abstract: A chair comprises at least a seat assembly, an armrest, a backrest, and a spring linkage. The backrest frame ends are connected to the upstanding back-leg frame ends of the seat assembly by the spring linkages to make a chair with a flexible spring backrest. Each spring linkage is of a U-shaped configuration having two ends spaced vertically apart; the upper end attached to the backrest frame and the lower end attached to the back-legs of the seat assembly. The tip of the spring linkage serves as a pivotal axis, allowing the backrest to be flexible and bend backwards in response to an applied force while returning to its normal position when the force is removed.

Abstract: A chair includes a base that has a generally U-shaped member. The generally U-shaped member is comprised of a front member attached to a first end portion and a second end portion. A seat is supported on the base and is moveable from an upright position to a reclined position. A first resilient member is attached to the first end portion of the generally U-shaped member. A second resilient is attached to the second end portion of the generally U-shaped member. End portions of the first and second resilient members are attached to the seat adjacent to a rear portion of the seat. The first and second resilient members are sized and configured to resiliently move or flex such that the seat is positioned at the reclined position when a user sits on the seat.

Abstract: A movable chair backrest is substantially composed of an upper board pivotally attached to a front of a backrest frame. A lower end of the upper board is connected to a lower board by a resilient sheet. A bouncing board connects between the lower board and the backrest frame. Therefore, the lower board operationally swings forward, backward, rightward, leftward relative to the upper board to correspond to different sitting and leaning postures of a user.

Abstract: A stackable chair having a back member may flex to allow for improved user comfort. An inline spring-to-frame configuration with a pair of spring members reinforced by steel plates on the top and bottom of each end of each spring is attached to the underside of the left and right members of the seat support frame. The spring-to-frame configuration may allow the back support frame to flex relative to the seat support frame.

Abstract: A resilient lower-back supporting device capable of vertical adjustment along with a backrest of a chair includes a resilient supporting unit pivotally connected between a lower end of the height-adjustable backrest and a supporting element. Configured for resilient extension and retraction, the resilient supporting unit includes an outer supporting rod and an inner supporting rod inserted therein. The two supporting rods are pulled toward each other by a spring provided therebetween. Besides, a spring is provided at an outer end of each supporting rod to bias the resilient supporting unit and the backrest toward a predetermined direction. With the backrest being vertically adjustable, and with the resilient support provided by a lower-back supporting portion at the lower end of the backrest, people of different heights are ergonomically supported especially on the lower back while sitting in the chair and are protected from back pain attributable to a prolonged sitting posture.

Abstract: A chair back according to embodiments of the present invention includes a rigid support member for reclinable attachment to a base, a flexible frame member having a flexible frame and a mesh, the mesh at least partially spanning the frame, and a seat attachment member moving in synchronization with the rigid support member at a different rate than the rigid support member during reclining of the rigid support member, wherein a first portion of the flexible frame member is affixed to the rigid support member, wherein a second portion of the flexible frame member flexes freely, wherein the seat attachment member contacts at least part of the second portion of the flexible frame member, wherein the first portion moves with the rigid support member and the second portion moves with the seat attachment member such that a curvature of the second portion increases as the rigid support member reclines.

Abstract: A seat back assembly (16) for a seat (10), comprising an upper seat back portion (24) for supporting an upper portion of a user's back and a lower seat back portion (22) for supporting a user's pelvis and pelvic region. The lower seat back portion (22) and the upper seat back portion (24) are independently adjustable. The upper seat back portion (24) can be reclined to one of a number of fixed angular positions and it is arranged and configured for dynamic angular movement under a load over a range of positions. The dynamic movement of the upper seat back portion (24) is controlled by a shock absorber (44) having adjustable damping means for providing a required level of tension and rebound in relation to the dynamic back action of the upper seat back portion (24).

Abstract: A chair includes a base that has a generally U-shaped member. The generally U-shaped member is comprised of a front member attached to a first end portion and a second end portion. A seat is supported on the base and is moveable from an upright position to a reclined position. A first resilient member is attached to the first end portion of the generally U-shaped member. A second resilient is attached to the second end portion of the generally U-shaped member. End portions of the first and second resilient members are attached to the seat adjacent to a rear portion of the seat. The first and second resilient members are sized and configured to resiliently move or flex such that the seat is positioned at the reclined position when a user sits on the seat.

Abstract: An angle-adjusting structure for a backrest of a chair is mounted at a rear side of a butterfly-shaped mounting member of the chair. The angle-adjusting structure includes a main body and a rotating member jointly passed through by a shaft having external teeth. A resilient element is mounted around an end of the shaft. A cover is secured to the main body by threaded fasteners. A pressing member is mounted on the other end of the shaft. By pressing the pressing member inward, the external teeth of the shaft are disengaged from internal teeth of the rotating member, and the rotating member is allowed to rotate freely. When the pressing member is released, the resilient element mounted around the end of the shaft extends outward to re-engage the external teeth of the shaft with the internal teeth of the rotating member, thereby securing the rotating member in place.

Abstract: A back support includes a base, a seat, and a back frame pivoted to the base. The seating unit has a flexible back (i.e., back shell) supported on the back frame and having stiff upper and lower sections connected by a forwardly protruding flexible lumbar section for providing lumbar support to a seated user. A spring mechanism is connected to the back frame and to a center lower edge of the flexible back. The spring mechanism biases the flexible back to bias the lumbar toward a forwardly protruding shape to provide optimal lumbar support when in the upright position and also during recline of the seated user.

Abstract: A chair comprises at least a seat assembly, an armrest, a backrest, and a spring linkage. The backrest frame ends are connected to the upstanding back-leg frame ends of the seat assembly by the spring linkages to make a chair with a flexible spring backrest. Each spring linkage is of a U-shaped configuration having two ends spaced vertically apart; the upper end attached to the backrest frame and the lower end attached to the back-legs of the seat assembly. The tip of the spring linkage serves as a pivotal axis, allowing the backrest to be flexible and bend backwards in response to an applied force while returning to its normal position when the force is removed.

Abstract: The invention concerns an arrangement for adjusting the seat back inclination of a seat into an optimum individual inclination position without manipulation or motor aids, which is characterised in that it comprises a sensor system for ascertaining the weight of the user of the seat and transfer of the result to a resilient element by way of which the sensor system result is transmitted to the seat back limbs.

Abstract: An improved chair is disclosed. The chair includes: (i) a seat; (ii) a base portion connected to the bottom of the seat; (iv) an upwardly extending support frame connected to either the seat or the base; and (v) a backrest connected to the support frame by a number of fasteners. The fasteners include a resilient member located between the backrest and the support frame, such that the backrest is spaced apart from the support frame.

Abstract: A backpost for use in wooden dining chair. The backpost unit provides reclining movements for a wooden chair of the type having a stationary frame section within which the backpost unit is secured. The backpost unit consists of an interlocking mechanism with minimum components and requires minimum maintenance and provides a solid and reliable reclining mechanism. The chair enables the user to secure an accurate posture of sitting during eating and also enables the user to enjoy a relaxing posture while sitting on the same dining chair.

Abstract: The chair according to the invention has a seat and a seat mechanism, wherein the seat and the seat mechanism are formed so that, during the sideways pivoting movement of the seat, the one side of the seat is movable independently of the other side of the seat, wherein the seat is mounted so as to be pivotable about a pivoting or rotation axis lying parallel to the knee axis of the user.

Abstract: A stackable chair has a backrest mounted on back supports by resilient mount units for tilting between an upright position and a tilted-back position. Each mount unit includes a rigid coupling member having a lower portion received within an upper end portion of the respective back support and pivotally joined to the respective back support and having an upper portion received within and affixed to a socket in the backrest. A compression spring received within the upper end portion of the back support and engaged between the lower portion of the coupling member and a front wall of the respective back support biases the backrest to the upright position. An armrest is slidably supported on an armrest support for simultaneous and controlled pivotal movement about a substantially vertical pivot axis of a rearward part of the armrest relative to a forward part of the armrest and translatory movement in a plane perpendicular to the pivot axis. Movements of the armrests permit dense stacking of the chairs.

Abstract: A chair comprising a support structure bearing a seat and a backrest, in which the backrest comprises a bearing portion and a connecting portion for connection to the support structure, in which the backrest is tiltable rearwards relative to a resting position under a rearwards thrust applied by the user and elastically returns to the resting position when the rearwards thrust ceases. The rearwards tilting of the backrest is formed in part by an elastic detonation of the bearing portion and in part by a displacement of at least a part of the connecting portion relative to the support structure.

Abstract: This present invention discloses a seat, comprising: a seat cushion; and a seat back frame connected to the seat cushion, the seat back frames being bent in a range of specified bending angle in a direction of moving the top end backward by a backward load over a predetermined value, by way of a joint provided at an intermediate portion in the vertical direction, such that the seat back frame receives a reaction force corresponding to the bending angle.

Abstract: A seat suspension assembly including a base including a first pair of spaced legs adapted to be securable to a support structure. The first pair of legs is connected to a back member. A seat frame is adapted to support a seating surface and disposed between the first pair of spaced legs of the base. The seat frame is movably connected to the base. The seat frame includes a first guide engageable with one of the pair of legs. The first guide permits controlled movement of the seat frame relative to the base. A suspension extends between the seat frame and the base for regulating the motion of the seat frame relative to the base.

Abstract: A stackable chair includes a seat assembly and flexible back support having a seat spring system attached therebetween. The seat assembly includes seat sides having spaced apart rear portions. The back support includes lower ends curved forwardly and disposed in registry with and separated by right and left gaps from respective seat side rear portions. Right and left spring members are disposed inwardly adjacent to bridge each gap. Each spring member includes forward ends connected to respective right and left front support members extended inbound from respective seat sides, and includes rear ends connected to opposed ends of a frame rear cross-member. The spring members allow limited reclining movement of the back frame. A limit to excessive forward movement of the back support is provided by pairs of fixation plates positioned in aligned and abutting relationship on upper surfaces of each respective forward and rear ends of each spring member.

Abstract: A chair comprises a seat support assembly including a seat support, the seat support assembly being adapted to stand on a surface so as to provide the seat support at a suitable height for a person to sit on, and a back support assembly, including a back frame member and a back support. In one embodiment, the back frame member has a curved middle portion substantially in the plane of the back support, and first and second end portions substantially in the plane of the seat support. The back frame member is flexibly interconnected to the seat support assembly by a first spring flexibly interconnecting the first end portion of the back frame member and the seat support assembly; and a second spring flexibly interconnecting the second end portion of the back frame and the seat support assembly.

Abstract: A chair with a flexible resilient back support structure includes a hollow tubular seat frame, a hollow tubular backrest frame pivotally connected to the seat frame, and a limit stop affixed to the backrest frame or the seat frame adjacent to the pivot points. The limit stop is configured to limit a degree of rotation of the backrest frame between an upright position and a maximum backwardly rotated position. An elongate spring element extends from within the backrest frame into the seat frame, and is configured to bias the backrest frame in the upright position, and to resiliently resist backward rotation. In various embodiments, a cam surface is associated with the spring element, providing an effective fulcrum point which moves rearwardly as the backrest frame reclines, thereby increasing the effective flexural resistance of the spring element during reclining.

Abstract: A chair with a flexible resilient back support structure includes a hollow tubular seat frame, a hollow tubular backrest frame pivotally connected to the seat frame, and a limit stop affixed to the backrest frame or the seat frame adjacent to the pivot points. The limit stop is configured to limit a degree of rotation of the backrest frame between an upright position and a maximum backwardly rotated position. An elongate spring element extends from within the backrest frame into the seat frame, and is configured to bias the backrest frame in the upright position, and to resiliently resist backward rotation. In various embodiments, a cam surface is associated with the spring element, providing an effective fulcrum point which moves rearwardly as the backrest frame reclines, thereby increasing the effective flexural resistance of the spring element during reclining.

Abstract: A joint is provided that automatically pre-tensions itself during assembly. The joint includes first and second structural members, such as a back upright and a pivot link in a chair. A torsion spring bushing and a pair of threaded anchors pivotally connect the first structural member to the second structural member. The anchor and back upright include mating angled surfaces that inter-engage and rotate the torsion spring bushing during assembly in a manner that pre-tensions the spring bushing while engaging the anchors in a direction parallel an axis of rotation defined by the joint.

Abstract: A chair having a seat and a back rest. The back rest is attached to the seat via a back rest support element. The flat spring can be made from a non-metallic material, such as from fiberglass. The back rest support element comprises a flat spring disposed under pretension. In one embodiment, the seat is disposed upon a seat support structure having four legs. Preferably, the legs are splayed outside the perimeter of the seat, so that the chair is stackable with chairs of like design. The seat and the back rest can be made from a lightweight plastic material, and that the support structure can be made from tubular steel.

Abstract: A stackable chair includes a base with a pair of inverted U-shaped leg members. Each of the leg members includes a front leg portion, a rear leg portion, and a generally horizontal portion interconnecting the front and rear leg portions. The base also has a generally horizontal seat cushion frame extending between the U-shaped leg members with the transverse front spring reinforcement bar extending side-to-side. A back support frame has a generally vertical portion with an upper and lower end and a generally horizontal end portion that extends from the lower end. The generally horizontal portion includes a transverse rear spring reinforcement bar. A spring member has one end interconnected with the front spring reinforcement bar and another end interconnected with the rear spring reinforcement bar. The spring member supports the back support frame such that the back support frame has an unstressed position and a reclined position.

Abstract: A chair including a seat assembly having an improved seat spring system to provide a flexible spring backrest frame. A pair of ends of spaced apart backrest frame members are arranged in registry with respective ends of seat support frame members, with each end positioned in spaced apart alignment across a gap from the respective end of each frame member. An elongated shaped flexible spring element spans each gap, with each spring element having opposed ends being extended a distance along each frame member from the gap. Each opposed end is restrained by a first and a second elongated U-shaped holder receptor paired and separately attachable to each opposed end of the spring element. Each holder receptor includes an opening end being faced towards and in alignment with the second holder opening end. The spring element is positioned between each opening end in side-by-side orientation beside the frame members, providing controlled angular range of motion of the backrest frame when moved by a chair occupant.

Abstract: A split back chair having a generally L-shaped seat member formed of a horizontal section and a vertical section, and separate independently movable right and left back portions. A first flat spring extends between and hingedly connects the back portions to one another and allows the back portions to pivot toward and away from another. A spring assembly connects each of the back portions to the seat member at right and left sides of the chair. Each spring assembly includes a cover plate and a second flat spring, both of which extend between the vertical section of the seat member and one of the back portions. A pair of removable arm rests are attached on the sides of the seat member. The cover plate houses the second flat spring and an end of the arm rests.

Abstract: An office-type chair which includes a seat assembly and back assembly that are pivotally supported on a chair base or pedestal to support a user thereon. To increase the comfort of the user, the seat assembly is tiltable forwardly and rearwardly by way of a tilt control mechanism while the back assembly thereof is tiltable laterally from side to side, i.e. in the leftward and rightward directions by way of a back torsion mechanism.

Abstract: A split back chair having a generally L-shaped seat member formed of a horizontal section and a vertical section, and separate independently movable right and left back portions. A first flat spring extends between and hingedly connects the back portions to one another and allows the back portions to pivot toward and away from another. A spring assembly connects each of the back portions to the seat member at right and left sides of the chair. Each spring assembly includes a cover plate and a second flat spring, both of which extend between the vertical section of the seat member and one of the back portions. A pair of removable arm rests are attached on the sides of the seat member. The cover plate houses the second flat spring and an end of the arm rests.

Abstract: A backrest for a seat includes an upper back portion having an integral, central extension, a lower back portion having a central cut-out, and hinges for pivotally connecting the upper and lower back portions together to permit free swinging movement of the extension through the cut-out about a pivot axis situated at a level above the extension so that substantially the entire extension can come out of the cut-out in a reclined position of the upper back portion to support the lower back of the seat occupant. The extension may be provided with a central recess separating two lateral prongs from one another, and an elastic band may then be used to span the recess between the prongs.

Abstract: A chair including a seat assembly having depending leg members and a hollow support frame having at least two open ends terminating beneath the seat assembly and a pair of upstanding, spaced apart hollow frame members arranged to provide a backrest frame part for the chair having at least two open ends extending beneath the seat assembly and in registry with the ends of the support frame, and flexible spring members secured between each pair of members to provide an articulated, flexible spring backrest for the chair beneath the seat assembly. Each flexible spring member includes an elongated, flat or blade spring member having its opposite ends secured within a holder member which is closed at one end and open at its opposite end for inserting the spring into the holder.

Abstract: An article of seating furniture (1) is constructed as a free oscillator having side members (6) with substantially Z-shaped resilient supporting sections (7), the supporting sections having a top end portion (9), a bottom end portion (8), and an intermediate portion (10) between them. The end portions (8), (9) of the supporting sections (7) are interconnected via a rod-shaped resiliently deformable reinforcing member (12) inclined oppositely to the intermediate portion (10) of the supporting sections. This construction prevents the chair from oscillating or seesawing excessively.

Abstract: A reclinable chair having a back and seat articulated for reclining movement of the back with respect to the seat, in which a plate having opposed faces disposed at an angle with respect to each other joins together the back and the seat. One of the plate faces is joined to the back, while the other of the plate faces is joined to the seat. A restoring force is exerted by the plate tending to restore the plate faces to the angle therebetween when they are forced away from that angle. The plate is preferably U-shaped, substantially encased in resilient material also U-shaped, with a flap of resilient material extending parallel to and between the legs of the plate.

Abstract: A chair provided with a seat carrier and an associated backrest carrier includes a pneumatic spring connected between the seat carrier and backrest carrier, and a mechanical draw spring one end of which is connected directly to the backrest carrier and the other end of which is connected to an adjustable lever pivotally mounted on the seat carrier. The pneumatic spring and mechanical spring are disposed in side-by-side parallel relation to one another between a pair of generally vertical spaced bars forming a portion of the backrest carrier. The force exerted by the mechanical spring is in opposition to the restoring force exerted by the backrest carrier so that movement of the lever to increase the force exerted by the mechanical spring reduces the total restoring force exerted on the backrest carrier.