Abstract: A body support assembly includes a seat assembly and backrest assembly supported by a tilt control assembly. Methods of using and assembling the body support assembly are provided.

Abstract: A chair assembly includes an arm assembly that includes an armrest supported by a vertically adjustable support assembly and an arm base, where the arm base extends at an acute angle with respect to a longitudinal centerline of the chair assembly, an upholstery arrangement including a ring member attached to a cover, where the ring member includes a plurality of reliefs having a width that reduces as the ring member is wrapped about a shell member of the chair assembly, and a control arrangement having a biasing member that moves through an arcuate path as the biasing member is adjusted between varying bias settings.

Abstract: A novel and improved device to assuage distressed infants by means of adjustable vertical motion combined with adjustable orientation. The motion is adjustable in terms of amplitude, frequency and time. The device allows the infants to be held face-inward or face-outward in the case of vertical orientation and prone or supine in the case of horizontal orientation.

Abstract: An oscillation system (1) for chairs includes a backrest support (3) oscillating about a rotation axis (4), a first support element (6) of the seat coupled to the frame (2) to assume, in the at rest position of the backrest support (3), a plurality of relative vertical positions with respect to the frame (2) depending on, and by effect of, a weight force applied to the first support element (6). A first elastic element (21) opposes an elastic reaction to the backrest support oscillation with respect to an at rest position of the backrest support (3). A lever (31) connects to the first support element (6) to be rotated by the first support element (6) during variation of the relative position, and connects to the first anchoring end (22) to displace the first anchoring end (22). A fulcrum axis (60) does not coincide with the rotation axis (4).

Abstract: A tilting mechanism (1) for chairs includes a support frame (2), a structure (4) rotationally coupled to the support frame. An elastic system (80) is interposed between the support frame and the structure to counteract a reaction to the tilting of the structure from an at-rest position to a tilted position. An adjustment system (20) is capable of varying the reaction to the tilting. The elastic system (80) includes at least one elastic element (12) and a first and a second stop element (81, 82) fastened at respective longitudinal end portions of the elastic element, respectively. In the at-rest position, the first and second stop elements are in contact with each other, and the elastic element (12) is in a deformed configuration and generates a residual elastic force that is at least partially released on the first and second stop elements.

Abstract: Seatback support structures may allow a user to selectively adjust the effective stiffness of a seat, between a plurality of settings, to increase individualized comfort for the user. A plurality of stabilizing members may be cantilevered with respect to a base member, with the amount of deflection of the stabilizing members in response to a given load being variable via a stiffness adjustment mechanism of the seatback support structure. Said stiffness adjustment mechanism may include a linkage that is mechanically moved with respect to the stabilizing members to adjust the weight distribution amongst the stabilizing members, thereby adjusting the effective stiffness of the seatback support structure. Such seatback support structures may be configured to operate substantially irrespective to changes in air pressure, and may be incorporated into any number of passenger seats, such as on aircraft, trains, and other vehicles. Methods of forming such seatback support structures are also disclosed.

Abstract: A seat back angle and depth adjustment assembly includes an angle adjustment member that includes a first aperture and a second aperture, a first fastener is received by the first aperture and is configured to engage an angle adjustment locking member, and a second fastener is received by the second aperture and is configured to engage a depth adjustment locking member.

Abstract: The invention relates to a mechanical assembly (2), said mechanical assembly (2) comprising, in addition to a leaf spring, at least one further spring element, the elastic restoring force of the at least one further spring element and the elastic restoring force of the one or more leaf springs supporting the seat shell (S) with a total restoring force, and/or the mechanical assembly (2) comprising at least two leaf springs and at least two supports, each support being associated with one of the leaf springs, and at least two supports being displaceable beneath the leaf springs by means of an adjustment mechanism and being displaceable on their trajectories by different extents.

Abstract: A chair is disclosed having a mechanism with a spring unit that permits mutually synchronous deflection between a backrest and a seat over a range between a respective zero position of back and seat inclination and a respective maximum back or seat inclination. Stationary first and second axes of rotation extend through a base support of a carrier unit. A back carrier is articulated on the first axis of rotation, and a third axis of rotation extends through the back carrier. A front of a base plate lies movably on the base support and a rear of the base plate is articulated on the third axis of rotation. The base support has a U-shape with two arms thereof having portions extending upward to engage associated openings in the base plate. When the mechanism is deflected, a relative displacement between the arms and the openings occurs.

Abstract: A furniture member may include a base assembly and a seat assembly. The base assembly may include a base structure, a post, a support frame, and a height-adjustment mechanism. The post extends vertically upward from the base structure. The support frame may include a cross member and a sleeve. The sleeve may slidably and rotatably receive the post for vertical movement of the support frame relative to the base structure along a longitudinal axis of the post and for rotational movement relative to the base structure about the longitudinal axis. The height-adjustment mechanism may include a height-adjustment actuator configured to move the support frame vertically along the longitudinal axis. The cross member of the support frame may include a pair of rocker springs mounted thereon. The seat assembly may be mounted on the rocker springs and may include a seat bottom, a seatback, and armrest members.

Abstract: Described herein is a shock mitigation apparatus. The shock mitigation apparatus may be utilized in a marine environment, able to absorb shocks transmitted to a seat system from a structure to which the seat is affixed. The shock mitigation apparatus includes at least one leaf spring wherein the leaf spring is cantilevered at one end and pivoted at a distal end thereof, and wherein the pivoted end is free to articulate upon flexure of the leaf spring.

Abstract: Chairs, seating systems, chair sub-assemblies and sub-systems, and associated methods of assembly and use. Aspects relate to chairs and methods of assembling chairs including chair controls of a relatively compact and effective design with desirable synchronous raising and tilting motions. Aspects also relate to tilt lock assemblies for achieving secure and effective tilt securement. Additional aspects relate to forward and rearward adjustment, or extension and retraction, of a seating assembly of the chair.

Abstract: A support mechanism for mounting a seat part to a foot part of a functional chair having a slide bearing which cooperates with a front section of the seat part, and a pivotable support part which is supported by a cantilever part and which is connected to a region of the seat part that is adjacent to the rear region of a seat surface section of the seat part.

Abstract: A chair assembly includes a seat support structure having a seat surface pivotable about a first pivot point between first and second positions, and a back support assembly coupled to the seat support structure, movable between upright and reclined positions and pivotable about a second pivot point, wherein the first pivot point is located at a position along a first line perpendicular to a second line tangential to the seat surface and at a forward most portion of a back surface, forward between along a third line parallel with the second line, down to the second line along a fourth line perpendicular with the second line, up the fourth line such that the second pivot point is located within a given radius from the first pivot point when the back support assembly is in the upright and reclined positions.

Abstract: An “invisible” syncro tilt mechanism is provided for chairs. The chair has a seat with a back portion and a seat pan portion and the seat pan portion is connected to the back portion and to a pivotable support structure, and thereby to a base. The mechanism has a generally closed track defined in the seat pan portion. A plunger is attached to a front portion of the pivotable support structure. The plunger is slidably disposed in the track. A spring is disposed in the track which is connected at opposing ends to the plunger and to a front end of the track. The mechanism does not extend or protrude outside of the seat pan. The mechanism provides synchronous movement of the plunger in the track.

Abstract: Among other things, a seat includes a base; a back-supporting surface coupled to the base; and a seating surface movable relative to the base in a direction of motion toward and away from the back-supporting surface. The back-supporting surface has a lower portion nearer the seating surface that is movable, relative to an upper portion of the back-supporting surface that is farther from the seating surface, in the direction of motion as the seating surface moves in the direction of motion.

Abstract: The adjusting mechanism serves for the weight-dependent setting of a restoring force which acts on a backrest (4) of an office chair which is configured with a synchronous mechanism. The synchronous mechanism comprises a support (12), a seat support (10) and a backrest support (8) which are connected to one another via joint pins (A1-A4), the restoring force being exerted via a spring element (18). In order to achieve as flat a design as possible, the restoring force is transmitted with the aid of a pivotable lever (16) via a front bearing pin (L1) to a first front joint pin (A1), an active lever length (h) which can be varied with the aid of an adjusting element (20) being defined by the spacing between the bearing pin (L1) and the second front joint pin (A2). A weight setting is made possible by the variation of the active lever length (h).

Abstract: A tilt mechanism (10) for a chair comprises a base (11), a first support (12) configured to support a chair seat and a second support (13) configured to support a chair back. The second support (13) is pivotably coupled to the base (11). A first coupling mechanism (41) couples the first support (12) with the base (11) and includes a first pin (40) slideably supported in a first linear guide slot (20). A second coupling mechanism (42) couples the second support (13) with the first support (12) and includes a second pin (44) slideably supported in a second linear guide slot (36). When the second support (13) pivots relative to the base (11), the first pin (40) is caused to be displaced along the first linear guide slot (20) and the second pin (44) is caused to be displaced along the second linear guide slot (36).

Abstract: A vehicle seat for a motor vehicle is provided. The vehicle seat includes a seat frame with a front seat shell and a rear cross member. Zigzag springs are arranged between the front seat shell and the rear cross member. Adjacently arranged first zigzag springs form a first spring arrangement and adjacently arranged second zigzag springs form a second spring arrangement, in which the zigzag springs comprise transversely running bearing legs on the end side for inserting the respective bearing leg into the front seat shell in a direction transverse to the seat frame. The bearing legs of the zigzag springs of the first spring arrangement can be inserted into the seat shell in a first direction and the bearing legs of the zigzag springs of the second spring arrangement can be inserted into the seat shell in a second direction that is opposite to the first direction.

Abstract: A control assembly for a chair including a base structure having a first pivot point and a second pivot point spaced from the first pivot point, a seat support structure pivotably coupled to the base structure for rotation about the first pivot point, a back support structure pivotably coupled to the base structure for rotation about the second pivot point, wherein the back support structure is adapted to rotate between a first and second positions, and a control link having a first end coupled to the seat support structure, and a second end coupled to the back support structure, wherein the control link rotates the seat support structure at a slower rate of rotation than a rate of rotation of the back support structure as the back support structure is rotated between the first and second positions.

Abstract: A chair assembly includes a base structure defining upper and lower portions, a seat support structure having forward and rearward portions, wherein the forward portion of the seat support structure is pivotably coupled to the upper portion, and wherein the seat support structure includes a seat support surface configured to support a seated user thereon, a back support structure having forward and rearward portions, wherein the forward portion of the back supported is pivotably coupled to the lower portion, and wherein the back support structure includes an upwardly extending portion adapted to move between an upright position and a reclined position, and a control link having a first end pivotably coupled to the rearward portion of the seat support structure, and a second end pivotably coupled to the rearward portion of the back support structure.

Abstract: A chair assembly includes a base structure, a seat support structure movably coupled to the base structure, an upwardly-extending back support structure movably coupled to the base structure, wherein the back support structure is adapted to move between an upright and reclined positions, wherein the back support structure is operably coupled to the seat support structure, a flexible shell structure defining a forwardly-facing surface forming a lumbar support, wherein the flexible shell is movably coupled to the seat support structure, and a resilient member generating a variable compressive force acting on the flexible shell structure in a manner that tends to cause a curvature of the back support structure to increase, and wherein the compressive force decreases as the back support structure moves from the upright position to the reclined position.

Abstract: A control assembly for a chair includes a base structure having a first pivot point and a second pivot point spaced from the first pivot point, a seat support structure having a forward portion pivotably coupled to an upper portion of the base structure for rotation about the first pivot point, a back support structure having a forward portion pivotably coupled to a lower portion of the base structure for rotation about the second pivot point, wherein the back support structure is adapted to move between a first and second positions, and a control link having a first end pivotably coupled to a rearward portion of the seat support structure for rotation about a third pivot point, and a second end pivotably coupled to a rearward portion of the back support structure for rotation about a fourth pivot point.

Abstract: A chair assembly includes a base structure, a seat support structure pivotably coupled to the base structure, a back support structure pivotably coupled to the base structure and including an upwardly extending portion adapted to move between an upright position and a reclined position, a control link having a first end pivotably coupled to the seat support structure and a second end pivotably coupled to the back support structure, a back support surface having an upper portion pivotably coupled to the back support, and a back link pivotably coupled to the seat support structure, wherein the back support surface is moved forward by the back link relative to the upwardly extending portion of the back support structure as the back support structure is moved from the upright position to the reclined position.

Abstract: A chair assembly including a first chair structure, a second chair structure, an actuator assembly coupled to the second chair structure to move the second chair structure between the first and second positions, a control input assembly coupled to the first chair structure, and a control link assembly coupling the control input assembly with the actuator assembly to move the second chair structure between first and second positions, and including a first shaft operably coupled to the control link, and rotatable about a second axis that is substantially orthogonal to the first axis and to the first direction, and first and second universal joint assemblies coupling the first shaft member to the second shaft, wherein actuation of the control input moves the second chair structure between the first and second positions.

Abstract: Reaction force mechanism for backrest of a chair has clear large space under the seat and uses a longer reaction force spring than the prior art. The mechanism includes a base member supported on a leg, a back support member coupled by a rotation shaft to the base member to recline and support the backrest, a seat support member to which the seat is mounted, a weight-dependent reaction force mechanism for moving the seat support member in a lifting direction, and a reaction force spring for applying a spring force for returning the back support member to an original position, in which the reaction force spring is disposed in a lateral orientation between the back support member and the seat support member.

Abstract: Device for synchronizing the tilt of a chair back and seat, of the type comprising a frame of the chair back (5), a frame of the seat (2) and a support (1) integral with the base of the chair, as well as at least one first crank (3), integral with the afore said frame of the chair back (5), and hinged (6, 7) at the rear to the frame of the seat (2) and to the support (1), and at least one second crank (4), hinged (8, 9) at the front to the frame of the seat (2) and to the support (1). The afore said first crank (3) and the second crank (4), with the frame of the seat (2), determine a articulated quadrilateral, wherein such a first crank (3) and such a second crank (4) lie substantially on skew lines.

Abstract: A chair chassis includes a base, a warped plate, a first adjustment member and a second adjustment member. The base including an upper cover, a lower cover and a front cover is arranged at a bottom surface of a seat of a chair. The warped plate is disposed under the upper cover of the base for connecting to a seat back of the chair. Two compression springs arranged in parallel with a certain interval are disposed between the first adjustment member and the warped plate for adjusting travel distance of the compression springs and changing a force of the seat back. The second adjustment member is used for lifting the chair by rotation of a second adjustment shaft. The chair chassis is fastened and adjusted by operating the second adjustment shaft to move along an axial direction. The chair chassis has simple structure, easy operation and improved applicability.

Abstract: The invention relates to a mechanism (2) designed for a chair, in particular for a rotatable office chair having a gas spring (12) vertically arranged in the underframe (1), the gas spring having a telescopically extendible piston rod so that the height of the seat (9) can be adjusted. The tilting adjustment of the seat (9) between the rest position (S0) and the relaxation position (Smax) occurs in synchronization with the adjustment of the backrest (96) between a rest position (R0) and a relaxation position (Rmax) inclined backward. The mechanism (2) has a shell (30), through which a stationary first rotational axis (D1) extends and on which a seat carrier (80) capable of being inclined is mounted.

Abstract: A chair and method of use is for a chair disposed upon a surface that is designed for a female anatomy; the chair includes a seat having proximate and distal end portions forming a first convex surface with a chord plane intersecting, the having a length shorter than its width. The chair includes a back having first and second end portions that form a second convex surface, wherein, a second lateral measure on the second end is less than a first lateral measure on the first end. The seat plane and an extension axis that is perpendicular to the surface are relatively positioned to one another to form an acute angle to one another, such that a user's femur bone lengthwise angles downward from hip to knee toward the surface while the user's shoulders arch rearward thus aligning the user's hip joint and shoulder joint vertically for better posture.

Abstract: A chair comprises a seat and a backrest support which are mounted on a support member, the backrest support being pivotal about a horizontal pivot axis, and an energy accumulator which is tensioned when the seat is subjected to a load and acts on the backrest support, the energy accumulator engaging the backrest support at an effective distance from the pivot axis. To improve the efficiency of such a mechanism, the energy accumulator is connected on the one side to the support member and one the other side via a transverse connector to the backrest support. With the mechanism the energy accumulator is subject to a load substantially by the rear region of the seat and thus substantially by the complete weight of a person sitting on the seat. In an alternative embodiment the seat comprises an elastic cover which on the one side is clamped in the support member and on the other side is connected to the backrest support, the elastic cover serving as energy accumulator.

Abstract: An adjustment device for chairs, comprising a main body (2), which can be engaged onto a supporting shank (3) of a chair; a prop element (6) mounted above the main body (2), which can be associated to a seat for a user; a backrest (10) mounted onto the main body (2), which can be associated to a back (11) for a user; and articulation means (14) for movably engaging the backrest (10) and the prop element (6) to the main body (2), the articulation means (14) comprise at least one lever (17) pivoting around the main body (2) in a first mounting site and having at least two lever portions (17a, 17b) hinged to the prop element (6) in a second mounting site and to the backrest (10) in a third mounting site, respectively, so as to obtain a given movement relation between the backrest (10) and the prop element (6).

Abstract: A chair includes a chair body, a connecting member, a back portion, and a restoring device. The chair body includes a base having a receiving chamber. The restoring device includes a threaded adjusting sleeve rotatably mounted in the receiving chamber, a threaded rod screwed into the adjusting sleeve, a pull cord having a first end mounted on the connecting member and a second end mounted on the threaded rod, and an elastic member biased between the base and the adjusting sleeve. Thus, when the back portion is pressed, the connecting member is driven to pivot about the chair body so that the back portion is moved to adjust its inclined angle. In addition, the elastic member provides a damping force to damp a further movement of the back portion to limit the inclined angle of the back portion.

Abstract: An adjusting mechanism is used to adjust a restoring force that acts on a backrest of a chair. The adjusting mechanism has a spring element for creating the restoring force, a support, and a backrest support that is pivotably mounted about a support axis on the support. An adjusting element configured as a pair of scissors containing a first scissor arm and a second scissor arm is provided, and the scissor arms are rotatably connected to each other about a scissor axis. The first scissor arm is pivotably mounted on the backrest support about an adjusting axis. A spring force produced by the spring element acts on the second scissor arm. A first actuating lever length is defined between the support axis and the scissor axis. The lever length is changeable using an adjusting element for adjusting the restoring force by pivoting the adjusting element about the adjusting axis.

Abstract: A mechanism for an office chair having a backrest support which may be pivoted rearwardly. Adjustment of the backrest pivotal motion is accomplished by the mechanism having a base support which may be positioned on a chair column, a seat support, the backrest support which may be pivoted to the rear, and a pre-tensioned spring arrangement for enabling the mechanism to counter or oppose the movement of the backrest support. The seat support and the base support form a movable unit, which may be moved relative to the chair column depending on the weight of a user applying a load to the seat support. Movement of the movable unit causes an adjustment of the pre-tension of the spring arrangement and/or an adjustment of the spring constant of the spring arrangement.

Abstract: A weight-responsive chair is provided which has a weight-activated mechanism that resists rearward tilting of a chair back upright while also effecting lifting of a rear portion of the seat to counteract the rearward tilt forces. The weight-activated mechanism includes a spring package connected between the chair frame and back upright which provides for ready mounting of same to the chair frame. Further, the rear seat portion is connected in lifting engagement with the upright but also includes independent suspension for the center of the rear seat portion to allow for independent movement and flexing thereof to improve comfort for the chair occupant.

Abstract: The synchronizing device comprises a seat carrier for carrying a seat of said office chair, a seat arm to be connected to a chair column of said office chair, said seat carrier being pivotable in relation to said seat arm about a transverse axis, a backrest arm connected to said seat arm and to said seat carrier such as to be pivotable about a transverse axis, a spring adapted to counter a synchronized movement of said seat carrier and backrest arm, and a sliding member extending substantially in a longitudinal direction of said seat and being articulated to said seat arm, said seat carrier being slidable in relation to said sliding member substantially in said longitudinal direction of said seat.

Abstract: A rotatable office chair comprises at least two seat carriers, each further comprising an upper arched guide and a lower arched guide, and at least two back rest carriers, each further comprising a restrictedly guided region, and a back rest arranged on back rest carriers, wherein the restrictedly guided region of the at least one back rest carrier is guided between the upper arched guide and the lower arched guide of the at least one seat carrier, thus allowing the at least one back rest carrier to be inclined relative to the seat carrier, wherein the upper arched guide and the lower arched guide are embodied at least in certain regions as an arc of a circle portion and wherein the arc of a circle portion of the upper arched guide and the arc of a circle portion of the lower arched guide have the same center of a circle.

Abstract: A tilt control mechanism for an office chair includes a spring assembly therein which controls the tilt tension on the back assembly. The tilt control mechanism includes a control plate mounted to the control shaft on which the uprights are mounted, wherein the control plate rotates in combination with the uprights. This control plate is located within the control body and cooperates with a front stop assembly and a back stop assembly to vary the limits of forward and rearward tilting of the seat and back assemblies. Also, the tilt control mechanism includes a pneumatic actuator assembly having fixed and rotatable cam blocks. The rotatable cam block rotates relative to the fixed block such that the rotatable cam block is driven downwardly to depress the control valve of the pneumatic cylinder and thereby vary the height of the seat assembly.

Abstract: A body support structure includes a body support member and a base having an upper component coupled to the body support member and a lower component adapted to be supported on a floor. An adjustable spring mechanism biases the body support member. A weighing mechanism is coupled to the adjustable spring mechanism. The weighing mechanism includes a height adjustment device disposed between the upper and lower components of the base. The height adjustment device includes a pneumatic spring having a pressure tube coupled to the lower component and a piston rod extending upwardly from and moveable relative to the pressure tube. A housing is disposed around the pneumatic spring and is coupled to the upper component. An adapter is coupled to the piston rod. A weighing spring is disposed between the adapter and the housing, with the housing moveable relative to the adapter between first and second weighing positions.

Abstract: A tilting device for a reclining chair including a support base that can be affixed to at least one pedestal, a mounting body for the back of a seat which is articulated on said support base rotatably around a first axis essentially orthogonal to said pedestal, a mounting plate for the seat of said surface of said seat which has its front end and back end rotatably articulated around a respective hinge axis generally parallel to said first axis respectively to said support base and to said mounting body, elastic means of thrust acting along a direction generally orthogonal to said first axis and having a first end acting on said support base and a second end acting on said mounting body and blocking means of said mounting body in at least two different angles relative to said support base and acting in opposition to said elastic means of thrust, said mounting plate assuming two corresponding different angles.

Abstract: An adaptive energy absorption system for a vehicle seat is disclosed, utilizing an adaptive energy absorber or variable profile energy absorber (VPEA) for mitigating occupant injury due to extreme vehicle movement (e.g., during a vehicle shock event), and/or for mitigating vibration experienced by an occupant of the vehicle seat during normal vehicle operating conditions. The adaptive energy absorption system achieves the aforementioned objectives for a wide range of occupant weights and load levels. Various configurations of dual-goal energy absorption apparatuses that enable both shock mitigation and vibration isolation are disclosed.

Abstract: A chair has a link of a chair back, a link of a chair seat, and a link mechanism that pushes up the link of the chair seat when the link of the chair back is pressed to incline rearward, so that the occupant can take the optimum seating posture without being conscious, thus further improving the comfort in the reclined posture.

Abstract: A chair according to embodiments of the present invention includes a base; a first linkage pivotably coupled to the base, a seat pivotably coupled to the first linkage, a second linkage pivotably coupled to the seat and pivotably coupled to the base, a back comprising a substantially upright portion and an attachment portion, the attachment portion pivotably coupled to the base at a first pivot point, and a third linkage pivotably coupled to the back at a second pivot point and pivotably coupled to the second linkage, wherein the second pivot point is on the attachment portion between the first pivot point and the substantially upright portion.

Abstract: A tilt control mechanism for an office chair includes a spring assembly therein which controls the tilt tension on the back assembly. The tilt control mechanism includes a control plate mounted to the control shaft on which the uprights are mounted, wherein the control plate rotates in combination with the uprights. This control plate is located within the control body and cooperates with a front stop assembly and a back stop assembly to vary the limits of forward and rearward tilting of the seat and back assemblies. Also, the tilt control mechanism includes a pneumatic actuator assembly having fixed and rotatable cam blocks. The rotatable cam block rotates relative to the fixed block such that the rotatable cam block is driven downwardly to depress the control valve of the pneumatic cylinder and thereby vary the height of the seat assembly.

Abstract: A shock absorbing device is provided that includes a cylindrical damper, a compression coil spring disposed around the damper having an axis substantially in line with the axis of the damper, and a cylindrical spring guide disposed around the compression coil spring so as to cover the compression coil spring.

Abstract: A seating furniture item, in particular an office chair, has a seat fastened on a seat support and a backrest fastened to a backrest support, the backrest support being articulatedly arranged on a base support and the backrest support and the seat support being articulatedly connected with each other via two levers, and in which one of the two levers is positively guided directly on the base support.

Abstract: A seating unit includes a base with a control housing, a back supported on the base for reclining movement, and a seat supported at least partially by a pivoting link on the base for synchronous movement with the back upon recline of the back. A back stop is operably mounted on a pair of parallel guide rods that extend transversely across the control housing for selective movement to a plurality of different positions where the back stop engages the link to limit movement of the seat and hence limit recline of the back to a plurality of selectable recline positions corresponding to the plurality of different positions.

Abstract: A seat, in particular an office chair, has a synchronous mechanism with a weight-adapting mechanism. An automatic adaptation of a spring force acting on the synchronous mechanism depends on the weight momentarily exerted on the seat. Therefore, the spring force is transmitted to the synchronous mechanism via a lever whereof the active arm length of the lever can be modified to adjust the spring force. The weight-adapting mechanism is configured such that the active arm length is automatically adapted to the weight momentarily exerted on the seat.

Abstract: A chair assembly has a chassis connected between a backrest frame and a pneumatic foot rod. The backrest frame has a pivotal hole and has an elongated slot to receive a sliding pivotal rod pushed by a spring so that the backrest frame is controlled by the sliding pivotal rod when the backrest frame pivotally moves relative to the chassis. Because the incline of backrest frame is controlled by an adjusting wheel pushing the spring and because the seat frame has a rocking board to support the backrest frame, the chair assembly is able to change the inclined angles of the backrest frame. Moreover, the seat frame has a sliding base for attaching a pad. Thereby, the chair assembly has adjustable functions.