Abstract: A chair is disclosed having a chair frame and a seating surface having a first side surface movably coupled to the frame, and a second side surface coupled to the frame. The first side surface is independently moveable relative to the second side surface. Each of the first side surface and the second side surface define a front end of the seating surface and a back end of the seating surface. A first actuator is coupled to the frame, where the first actuator is configured for operative communication with the first side surface.

Abstract: A reversible seat assembly for use with an airplane. The reversible seat comprises a base assembly and a vertical assembly. The base assembly and the vertical assembly are connected to a support structure and are collectively disposable into and out of a first travel position, a second travel position, and a third travel position. In the first and second travel positions a user or passenger may assume a usual sitting position. In the third travel position the user may assume a reverse sitting position. The base assembly comprises a right segment and a left segment connected and rotationally movable to a central segment. The vertical assembly comprises a lower segment and an upper segment connected to and rotationally movable a middle segment. The reversible seat assembly may further comprise a back armrest connected to an opposite side of said middle segment and structure to provide support to the arms of the user.

Abstract: In a seat reclining device, a seatback frame forming a skeleton of a seatback is coupled to a seat cushion frame to be rotatable about a shaft with respect to the seat cushion frame. One end portion of a first sliding bracket is rotatably coupled to a middle portion of the seatback frame by a driving unit. The other end portion of the first sliding bracket extends toward a vehicle body located behind the seatback. A second sliding bracket is mounted on the vehicle body located behind the seatback and extends toward the first sliding bracket in a front and rear longitudinal direction to be connected to the first sliding bracket. The second sliding bracket is configured to guide a sliding movement of the first sliding bracket while the first sliding bracket is being rotated.

Abstract: A robot includes: a microphone assembly to which a voice is input; an accelerometer connected to a noise source; and a controller configured to control the microphone assembly, wherein the microphone assembly includes: a microphone housing formed in one surface thereof with an opening and formed therein with a space; a microphone accommodated in the space; and an anti-noise speaker accommodated in the space and spaced apart from the microphone, and the controller includes an anti-noise generator configured to output a signal corresponding to an anti-noise against the acquired noise to the anti-noise speaker.

Abstract: The invention relates to an actuator assembly for an adjustable seating or lying furniture item, in particular for an adjustable bed or an adjustable comfortable armchair, comprising a spindle that can be activated by means of a drive for causing axial rotation, which is mounted in a stationary manner. The actuator assembly also comprises a sliding block mechanically coupled with the spindle, the sliding block can be moved parallel in relation to a longitudinal axis of the spindle when said spindle is activated. The actuator assembly also comprises a coupling element mounted in a manner allowing it to be moved in relation to the spindle with a first slotted guide, in which the sliding block is at least partially guided in such a way that the coupling element is shifted when the spindle is activated, in order to move a segment of the adjustable seating or lying furniture item that can be mechanically coupled with the coupling element.

Abstract: A battery system includes a traction battery and at least one controller that implement a model of the traction battery. The system may monitor current input and voltage output of the traction battery. The at least one controller may inject a plurality of current signals into the battery when it detects the input current to be approximately zero and a corresponding terminal voltage to be generally constant. Each of the injected current signals has a discrete frequency. The controller may measure voltage responses to the injected currents indicative of impedances of the traction battery at the discrete frequencies. The controller may output parameters representing an equivalent circuit model of the traction battery based on the impedances, and operate the battery based on the parameters.

Abstract: A chair, especially an office chair, includes a seat that is fastened on a base support unit, a backrest that includes a back lower region and an upper shoulder region and is fastened to a back support, the back support being supported by the base support unit in a manner permitting rotation about an inclination axis. The shoulder region is connected to the back support in a manner permitting inclination about a shoulder axis and is hinge-connected to a back lower region at a lumbar region, and the back lower region further extends along a chair element so that when the shoulder region is inclined about the shoulder axis, an angle of the shoulder region relative to the back lower region is changed.

Abstract: A lumbar support seat is disclosed for supporting lumbar vertebra portion, which stably supports the lumbar vertebra portion and the pelvis portion so as to maintain proper posture and comfortable sitting. The lumbar support seat includes a seat main body having an upper central portion that is curvedly indented so as to correspond to the shape of pelvis portion; a lumbar supporting die including fixing frames fixed at the upper portion of the rear end of the seat main body, and a base plate for supporting lumbar vertebra portion. The pelvis portion is supported via the seat main body and the lumbar vertebra portion is stably supported via the lumbar supporting die. The lumbar support seat helps a user to sit with proper and comfortable posture.

Abstract: A device for guiding a seat belt on a seat having an integrated seat belt. In order to provide a device that can be economically and easily installed, that ensures reliable guidance of the seat belt inside the backrest (1) of a seat having an integrated seat belt in a simple manner, and that prevents pinching of the seat belt (2) during adjustment inside the backrest (1), the seat belt guide has at least one upper seat belt guiding element (6). The guiding element (6) is above a pivot axis (5) of a multi-piece backrest (3, 4) of the seat having an integrated seat belt. At least one lower seat belt guiding element (7) is also provided below the pivot axis (5) of the multipiece backrest (3, 4) of the seat having an integrated seat belt.

Abstract: A seat adjustment device adjusts the pivoting angle formed by a first seat member and a second seat member. A hinge shaft connects at a first connection point, the first seat member, and the second seat member. An arm section and a connection mechanism are connected at a second connection point. The positions of the axes of the first connection point, the second connection point, and a pivoting section are set in such a manner that, when a load is applied to the front end of either the first seat member or the second seat member, the distance from the second connection point to the axis of the pivoting section is less than the distance from the first connection point to the second connection point with respect to the direction perpendicular to the line of action of a load applied to the second connection point.

Abstract: The invention is a Modular Airplane Seat Unit (1), where the seat can be lowered into the floor of a passenger cabin (9) via telescopic structure (14) and covered by sliding covers (12). The modular seat unit is to be utilized in passenger airplanes providing a more comfortable and healthy flight to the passengers, and more than one additional options like Coffee Table and Leg Rest.

Abstract: A reversible seat comprising a backrest, a seat bottom, two guide bars, and two corresponding backrest support assemblies. The guide bars are attached to and disposed on either side of said seat bottom and are disposed on the outside of a base assembly of the seat bottom. The backrest is attached to and disposed between the backrest support assemblies. The backrest support assemblies include a plurality of spindles and a spindle carrier. The spindles of each assembly are in rotational communication with their respective guide bar, providing a sliding engagement. The backrest is pivotably engaged with the backrest assemblies so that it can be adjusted depending on the seating position. The backrest assemblies translate longitudinally across guide bars to provide a plurality of seating positions. The backrest assemblies may also include locking members that engage the base assembly of the seat bottom for securing the backrest in place during use.

Abstract: Embodiments of the present invention include a seat back pivotally coupled to a seat frame via a pivot shaft, wherein a lower end of the seat back does not extend below the pivot shaft, a seat pan fixedly coupled to the seat frame, at least one quadrant arm fixedly coupled to the seat back and pivotally coupled to the pivot shaft, and a recline lock coupled to the one quadrant arm and the seat frame. The pivot shaft is coupled to the seat frame at a high pivot location, wherein the seat back is configured to pivot adjacent a lumbar region of a passenger's back. The seat pan may optionally include an extension from the seat pan that is configured to couple to the pivot shaft and fill a seat back aperture located between the lower end of the seat back and the seat pan.

Abstract: A seat (1) includes a seat cushion (2); a seat back (3) divided into an upper seat back (4) and a lower seat back (5), the upper seat back (4) and the lower seat back (5) being connected in way that their respective angles can be adjusted; recliner drive means (7) capable of varying a reclining angle which is an angle of the lower seat back (5) to the seat cushion (2); middle bend drive means (10) capable of varying a middle bend angle which is an angle of the upper seat back (4) to the lower seat back (5); and a control part (13) configured to perform interlock control for interlocking the reclining angle and the middle bend angle on the basis of a predetermined interlock function.

Abstract: A mounting member is adapted for joining a seat back to a frame. The mounting member includes a base and an extension projecting from the base along an axis in absence of external forces to the extension. The extension has an end distant from the base that is connectable to the seat back and that is resiliently linearly movable in directions substantially perpendicular to the axis 360° about the axis.

Abstract: A back portion for a chair has a back frame, the back frame having a lower portion adapted to extend across at least a major part of a lower region of a seated adult occupant's back, an upper portion vertically spaced from the lower portion and adapted to extend across at least a major part of an upper region of the occupant's back, and a relatively narrow interconnecting region between the upper portion and lower portion. The relatively narrow interconnecting region is resiliently flexible to provide a flexing movement in a rearward direction of the upper portion relative to the lower portion. A cover operatively connected to the back frame provides a supporting surface for the back of the seated occupant.

Abstract: A chair with a back-and-forth moving backrest comprises a seat and a backrest, the lower end of the backrest is separated from the seat; both sides of the lower end of the backrest are respectively connected with both sides of the back end of the seat by a rotating mechanism; the lower end of the rotating mechanism can be rotatably regulated relatively to the seat; the upper end of the rotating mechanism can be rotatably regulated relatively to the backrest; during the rotating regulation of the rotating mechanism, the backrest only moves back and forth relatively to the seat without changing the vertical state of the backrest.

Abstract: A back support is pivotally oriented to locate a pivot point relative to posterior superior iliac spines of a seated user, such that when an upper portion of the back support contacts the upper torso of the user and moves to a desired angular orientation to balance the upper torso over the pelvic area, the back support transfers support to the posterior superior iliac spines to maintain the pelvic skeletal structure in alignment. A lower portion of the back support angularly contacts, supports and confines gluteal and buttocks tissue of the user independently of the degree of pivotal orientation of the upper portion.

Abstract: A chair includes a supporting structure, a seat moveably mounted on the supporting structure and moveable with respect to the supporting structure in a vertical direction, and a backrest including a first frame pivotally connected to the seat and a second frame separate from and pivotally mounted on the first frame to connect to the seat. Further, a first control device is mounted and concealed between the first and second frames in order to prevent the user from inadvertently colliding with it. The first control device is adjusted for various relative pivotal positions of the first and second frames.

Abstract: Follow-up performance to respiratory movements is made higher than that of the prior art without obstructing movements of the pelvis of a person. A configuration is adopted that a cushioning member arrangement frame for a seat back 34, 140 and a cushioning member arrangement frame for a seat cushion are displaced according to load fluctuation to a cushioning member for a seat back 40, 150 or a cushioning member for a seat cushion 20. That is, such a configuration is adopted that the cushioning member arrangement frame for a seat back 34, 140 or the cushioning member for a seat cushion 20 not only moves according to load fluctuation but also frames themselves supporting them move via tension structure members spread over the frames (a cushioning member for a seat back and a cushioning member for a seat cushion).

Abstract: The chair of the invention includes a cushion, a back and a back support. Either or both of the back and back support are made of a flexible material. The back is perpendicular to the cushion and has an upper connecting portion and a lower connecting portion. The back support is of a substantial L-shape and has an upper end and a protrudent mount. The back support is connected between the cushion and the back for supporting the back. The upper end of the back support fixedly connects with the upper connecting portion, and the protrudent mount movably and pivotally connects with the lower connecting portion, thereby the back support is capable of tilting.

Abstract: An upper portion of the back is pivotable relative to the lower portion between a neutral position and an extended position, with the upper portion being pivotable relative to the lower portion independent of the tilt position of the back. In one aspect, an adjustment mechanism is coupled between lower and upper back support members and pivots the upper support member between at least first and second support positions.

Abstract: Angle adjustable backrest made of a lightweight, durable, adjustable, backrest for ultralight manual wheelchairs. Light-weight material can include composites for a rigid backrest for promotion of healthier and functional interface. Angle adjustment can be any desired range such as a range from ?5 degree to 55 degrees (i.e. 85 degrees to 145 degree with respect to horizontal with the seat). No tools are necessary for any of the angle adjustments. The backrest has a horizontal adjustment (fore-aft) that can be any desired range such as 1 inch. The height selection depends on the length of the wheelchair frame tubes. The present invention improves the ease and simplicity of adjusting the backrest by or for the user, as well as enhances the aesthetic appearance and adds features necessary for achieving commercial readiness. The present invention can be retro fit onto a wide range for ultralight wheelchairs.

Abstract: A seat adjustment mechanism, which adjusts an angle formed between first and second seat members rotatably connected to each other, includes a first link member adapted to be connected to the first seat member and including a first end rotatably supported by the first seat member, a second link member adapted to be rotatably connected to the second seat member and including a first end rotatably supported by the second seat member and a second end rotatably connected to the first link member, a drive device, and an extending and retracting device driven by the drive device and extending and retracting linearly, wherein one of the drive device and the extending and retracting device is rotatably connected to a second end of the first link member and the other of the drive device and the extending and retracting device is rotatably connected to the second seat member.

Abstract: A chair has a supporting frame, a seat portion, a back portion, and a recline mechanism. The mechanism moves the seat portion upon a reclining action of the back portion. The mechanism has a rear deformable member and a front deformable member operatively connecting the seat portion and the supporting frame. The recline mechanism also has a lower deformable member operatively connecting a lower part of the back portion and the supporting frame, and a puller member above the lower deformable member. The recline mechanism is configured such that as the back portion is reclined, the lower deformable member deforms and the puller member applies a rearward pulling action which causes the seat portion to move and the front and rear deformable members to deform.

Abstract: A backrest for a vehicle seat includes a backrest frame, which is surrounded by a cover and has an upper backrest with an adjustable inclination. An additional frame is hinged so as to be pivotable about a pivot axis to a side plate, the cover, or the backrest frame. The pivot axis is arranged in an upper region of the backrest, and the additional frame extends upwards from the pivot axis in the installed position of the backrest. The additional frame can be secured in different angular positions in relation to the backrest frame, and, thus, a variable gap forms between the additional cover of the additional frame and the cover of the backrest frame.

Abstract: A reclinable chair is disclosed having right and left side connectors for pivotally connecting a backrest to a base assembly. The connectors bias the backrest into the upright position when unoccupied. In certain embodiments, the connectors can comprise elastic members, ball joints, or a plurality of elastic springs.

Abstract: An ergonomic chair having a seat with selectively located slot patterns or spring mechanisms to reduce pressure on the occupant of the seat and a flexible back that allows the occupant to recline while at the same time providing lumbar support. An embodiment of the chair may be telescopically stacked in a space-saving configuration of a plurality of identical chairs.

Abstract: The present invention intends to arrange the appearance of furniture at a connecting portion between a first member having stiffness and a second member movable relative to the first member and having stiffness without forming the connecting portion in an unnaturally large diameter. More specifically, the present invention provides a structure for connecting members comprising: a first member having stiffness; a second member movable relative to the first member and having stiffness; and a spring member in which an end portion thereof is connected to the first member and other end portion thereof is connected to the second member so as to accumulate a reaction force by elastic deformation, wherein the spring member is formed into a frame-like shape extending along the first and second members.

Abstract: A vehicle seat device includes a seat cushion frame and a seatback frame including a lower-side frame supported at a lower end portion thereof to be tiltable relative to a rear end portion of the seat cushion frame, an upper-side frame arranged at an upper portion of the lower-side frame, and a center bending mechanism coupling the lower-side frame and the upper-side frame to be bendable forward, wherein the center bending mechanism bends the upper-side frame about a rotational center that is ahead of a seatback outer layer covering a front surface of the seatback frame. The movement of the upper-side frame when tilted comes close to the movement of the passenger who bends forward. The slip between the seatback outer layer and the back of the passenger can be minimized, and thus, it becomes possible to lessen an uncomfortable feeling of a passenger.

Abstract: A center-foldable seat back has a seat back upper part that can be tilted forward relative to a seat back lower part. A trim cover is provided, sewn along the entire periphery at the mutual contact position of an upper and lower cover, the pulled-in state is modulated by cloth pieces, thereby preventing wrinkles. The seat back is provided with the trim cover in which one cloth piece one side edge of which is sewn to the ends of the lower and upper cover is provided at least in the central portion on the inside of the trim cover, the cloth piece is extended inward, the other side edge thereof is sewn to a fastener, the central portion on the back side is extended inward and sewn to the fastener, and the central portion on the inside of the trim cover is sewn to open and close by one fastener.

Abstract: A seat including a plurality of user support assemblies that are independently adjustable. User support assemblies, which are independently adjustable, include a head support assembly, a thoracic support assembly, and a lumbar support assembly. Moreover, the seat might include a independently adjustable seat assembly.

Abstract: An angle-adjusting structure for a backrest of a chair is provided. The angle-adjusting structure, mounted at a rear side of a butterfly-shaped mounting member of the chair, 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: An easily operable lock device for a movable member of a chair, the lock device being adapted such that a person sitting on the chair can select lock or unlock position by operating operation means with a load, such as the weight of the person, acting on the movable member and, when the load is removed after the selection of the lock or unlock position, lock or unlock operation is executed. A lock pin provided at a spring receiving member functioning as a movable member, is selectively engaged with and disengaged from engagement holes formed in a reinforcement plate functioning as a support member. The lock device has biasing means for biasing the lock pin toward the lock position when an operation member moved by the operation means is set at a lock reservation position and biasing the lock pin toward the unlock position when the operation member is set at an unlock reservation position.

Abstract: A vehicle seat may include a seat back that includes an upper half corresponding to a shoulder portion of a passenger, a lower half corresponding to a waist portion of the passenger, at least one angular adjustment mechanism and at least one upper half height adjustment mechanism. The at least one angular adjustment mechanism is disposed between the upper half and the lower half and is arranged and constructed to tilt the upper half back and forth relative to the lower half to intermediately fold the seat back at an intermediate folding position. The at least one upper half height adjustment mechanism is disposed in the upper half and is arranged and constructed to vertically move the upper half relative to the intermediate folding position.

Abstract: A chair includes a base, a seat mounted on the base, a support bracket mounted on the seat, an upper backrest having an upper portion pivotally mounted on the support bracket, and a lower backrest pivotally mounted on a lower portion of the upper backrest. Thus, when a user's back is rested on the upper backrest and the lower backrest, the upper backrest and the lower backrest are pivotable relative to the support bracket to rest on the user's upper and lower backs respectively to support the user's whole back snugly and completely to prevent the user's lower back from depending in the air so as to provide a comfortable sensation to the user.

Abstract: A chair has a supporting frame, a seat portion, a back portion, and a recline mechanism. The mechanism moves the seat portion upon a reclining action of the back portion. The mechanism has a rear deformable member and a front deformable member operatively connecting the seat portion and the supporting frame. The recline mechanism also has a lower deformable member operatively connecting a lower part of the back portion and the supporting frame, and a puller member above the lower deformable member. The recline mechanism is configured such that as the back portion is reclined, the lower deformable member deforms and the puller member applies a rearward pulling action which causes the seat portion to move and the front and rear deformable members to deform.

Abstract: A vehicle seat, comprising an upholstered seat surface and an upholstered backrest, whereby the backrest may be folded forward about a first horizontal pivoting axis. A backrest element is integrated close to the front side of the upholstered backrest, which may be pivoted in the backrest about a second horizontal pivoting axis, which, in side view, is higher than the first horizontal pivoting axis. The backrest element is curved in the region of the second horizontal pivoting axis, such that an upper backrest piece is formed above the second horizontal pivoting axis and a lower backrest piece is formed below the second horizontal pivoting axis, which are inclined towards each other in the direction of the front side of the backrest.

Abstract: A vehicle seat may include a seat back that includes an upper half corresponding to a shoulder portion of a passenger, a lower half corresponding to a waist portion of the passenger, at least one angular adjustment mechanism and at least one upper half height adjustment mechanism. The at least one angular adjustment mechanism is disposed between the upper half and the lower half and is arranged and constructed to tilt the upper half back and forth relative to the lower half to intermediately fold the seat back at an intermediate folding position. The at least one upper half height adjustment mechanism is disposed in the upper half and is arranged and constructed to vertically move the upper half relative to the intermediate folding position.

Abstract: A structure for attaching a frame-like spring being capable of effectively reducing the number of parts, is provided. According to this structure, a reaction force frame element which is a frame-like spring is attached via a lower frame portion and an upper frame portion so that pressurization is always provided in the movable range and the pressurization becomes the lowest at a predetermined position of a normal posture. Specifically, when the a reaction force frame element is made into the attaching preparation posture that the elastic repulsive forces are accumulated rather than a normal posture, the upper attaching portions include insertion portions for allowing insertion of lower ends and engagement portions to be engaged to the lower end portions due to an elastic repulsive force when the external force is released.

Abstract: A movable backrest for a chair comprises a frame that is fixed to the chair, at least a flexible connecting element connected to the frame, and at least a backrest connected to the connecting element. Since the connecting element is flexible, the backrest and the back of the user can be moved simultaneously along with the movement of the back of the user, providing a comfortable support to the back of the user.

Abstract: The invention relates to furniture, in particular to sitting devices and can be used as a work chair or therapeutic furniture. The aim of said invention is to develop a sitting device which would make it possible to efficiently relieve the backbone in a sitting posture taking into consideration individual morphological and functional asymmetries, thereby normalizing the work of other organs and systems of an organism, first and foremost the organs of the small pelvis, optimizing the “turtuosity” of the backbone associated with constitutional and geophysical factors.

Abstract: A collapsible wingback chair that includes a seat base portion and to which is secured a lower portion of a pair of side wings that include upper portions that are movable relative to a chair back that is pivotally mounted so as to be movable between an upright position when the chair is in use to a folded position in overlaying relationship with the base with the upper portions of the side wings also being folded relative to the base to thereby form a compact configuration for handling, shipping and storage. The side wings are selectively secured to the chair back when the back is in a raised position to thereby permit use of the chair in a conventional manner.

Abstract: A chair backrest adjusting mechanism includes a seat supporting frame, a backrest supporting arm, amount, a supporting arm cover, and a ball-shaped handle. The seat supporting frame is fixedly connected at a lower end to a base below a chair seat, and pivotally connected at an upper end to two pivot brackets at a lower end of the backrest supporting arm, which is further pivotally connected at an upper end to the mount on a rear side of a chair backrest. The supporting arm cover is fitly covered on the backrest supporting arm with upper and lower ends pivotally connected to the mount and the upper end of the seat supporting frame. A threaded rod is fixedly mounted in and turned via the ball-shaped handle to drive the backrest supporting arm to tilt forward or backward, and accordingly adjust the backrest to different positions relative to the chair seat.

Abstract: A movable backrest for a chair comprises a frame that is fixed to the chair, at least a flexible connecting element connected to the frame, and at least a backrest connected to the connecting element. Since the connecting element is flexible, the backrest and the back of the user can be moved simultaneously along with the movement of the back of the user, providing a comfortable support to the back of the user.

Abstract: The elastic support structure for human body to lean against includes a connecting frame, a swing rack, and an elastic rod. The connecting frame includes a connecting surface and a positioning part for the support structure. The swing rack has its first end placed on one end of the connecting frame, which makes the second end of the swing rack swing. At least two elastic rods are placed on the same side of the connecting frame and swing rack, and two movable parts of the support structure. A multi-directional swing is created. The movable part of the support structure uses the swing feature of the second end of the swing rack, so that the movable part creates a greater range of swing in the corresponding direction.

Abstract: A seat assembly supports an occupant in a passenger compartment of a vehicle. The seat assembly includes a seat cushion pivotally coupled to the vehicle for movement about a first pivot axis between a generally horizontal seating position and a generally upright stowed position. The first pivot axis being fixed with respect to the vehicle. The seat assembly also includes a seat back pivotally coupled to seat cushion for pivotal movement relative to the seat cushion about a second pivot axis, such that the seat back is displaced rearwardly as the seat cushion is moved toward the stowed position.

Abstract: A backrest includes: a back support having a top end portion provided with a pivot shaft that has two opposite end portions; a backrest cushion having a rear wall formed with two threaded holes; a coupling cover having an open end, covering the pivot shaft, and having a back wall that is formed with two counter bores; two screw bolts extending respectively through the counter bores and engaging threadedly and respectively the threaded holes to permit abutment of the open end of the coupling cover against the rear wall of the backrest cushion; and two pivoting members, each having a pivot sleeve sleeved rotatably on a respective end portion of the pivot shaft, and a linkage extending from the pivot sleeve and coupled to a respective one of the screw bolts.

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: 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.