Abstract: A height adjustable bassinet with two height adjustable columns and associated assist cylinders. The bassinet includes a height adjustment assembly to operate the assist cylinders from manual actuators, such as paddles, located approximately in four corners of the bassinet support surface. The height adjustment system may include a pair of paddle assemblies mounted under the bassinet support surface. The paddle assemblies may be coupled to the assist cylinder by a dual linkage that translates pivotal movement of any individual paddle into movement sufficient to simultaneously actuate both assist cylinders. The dual linkage may include a pair of drive rods coupled to a pair of actuator rods by a plurality of pivot arms. The pivot arms may be generally “L” shaped and arranged in a rectangular configuration so that each drive rod is operatively coupled to two pivot arms and each actuator rods is operatively coupled to two pivot arms.

Abstract: A forward tilt assembly configured to tilt forward a seat of a chair. The forward tilt assembly includes a base, a seat plate, and a release mechanism. The seat plate is pivotally mounted to the base and includes two support brackets on the sides of the seat plate. Each support bracket includes a keyhole slot. The release mechanism is operable between locked and unlocked positions and includes a slidable lock pin mounted between the support brackets. The release mechanism includes two keyed collars, one disposed at each end of the lock pin. The collars are received in respective keyhole slots of the support brackets. When the release mechanism is in the unlocked position, the collars are unobstructed from moving within the keyhole slots, and the seat plate can pivot relative to the base, thereby tilting a rear of the chair seat.

Abstract: A piece of seating furniture includes a backrest and a seat. The seat is operatively connected to the backrest. The backrest and the seat, during a pivoting of the backrest, open one another at an opening angle. A backward-tilt stop is included for limiting relative movement of the seat and the backrest. The backward-tilt stop is situated in extension of a vertical support of a pedestal.

Abstract: A mechanism for an office chair allows a pivoting resistance of a backrest support to be altered. The mechanism for the office chair, in which a small adjustment travel is sufficient in order to realize a large adjustment range of the pivoting resistance of the backrest, has an actuating element connected to the backrest support with a supporting and/or guide track for a functional element. The functional element brings about a change in the spring tension of a spring element during pivoting of the backrest support.

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 has a supporting frame, a seat portion for supporting an occupant, and a back portion for supporting the back of a seated occupant. The portion is reclinable relative to the supporting frame between a generally upright position and a generally reclined position. A preference control is operatively engaged between the back portion and a chair component, wherein displacement of the back portion toward the generally reclined position causes displacement of the chair component. The preference control is adjustable to vary the amount of displacement of the chair component caused by a given amount of displacement of the back portion toward the generally reclined position.

Abstract: A chair that includes a support module, a seat carrier, an initially forwardly declined seat member articulated to the seat carrier such as by being pivotal along a front, and an initially rearwardly angled backrest carrier having a backrest member, the carrier articulated to the seat carrier such as by being pivotal along a lower end. The angular positions of the seat and backrest member are largely controlled via an actuator arm and adjustable spring arrangement, wherein the actuator arm directly links the seat member to the backrest carrier and the spring arrangement returns the backrest carrier and seat member to initial positions when a weighted load is lessened or removed from the rear of the seat member. A pneumatic cylinder to provide resistance to the seat member, a limiter to limit a maximum and minimum angular position of the seat member, adjustable arm rests, and casters may be included.

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

Abstract: A 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: 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 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 chair (1), in particular a swivel office chair, is provided with a bottom chair part (2) having a column (3), a seat support (4) held on the bottom chair part (2), a seat (6) connected pivotably to the support, and a backrest support (5) holding a backrest (7) and connected pivotably to the seat support (4). The movement of the seat (6) is coupled with the movement of the backrest support (5) by a synchronizing mechanism having at least one spring (10) and coupling elements. The synchronizing mechanism is arranged essentially within the column (3).

Abstract: An office chair having a resilience tilt-adjusted device of a backrest includes an upper and a lower casing put together to cover an elastic adjuster which can press one end of elastic members with difference forces. Another end of the elastic members leans against an axle rod which is disposed at the lower end of the backrest supporter. The two ends of the axle rod pass through the casing. The lower end of the backrest is pivotally connected to a predetermined area within the casing as a pivot for swinging. A positioning rod having a rack is passed through the center of the axle rod so as to insert the rack onto the guiding groove of the casing. A positioning piece is arranged upon the rack and can be controlled to move up and down for inserting its end into the rack. Therefore, when the positioning piece is inserted into or exited from the rack, the backrest supporter can be positioned in a desirable angle after tilting.

Abstract: A tilt control mechanism for an office chair includes a spring assembly therein which controls the tilt tension on the back assembly. This tilt control mechanism includes a tension adjustment assembly having a radial adjustment arm which supports the legs of a pair of coil springs and a cooperating cam block which cooperates with the arm to drive the arm upwardly and downwardly to vary the tilt tension. The cam block is mounted on a threaded shaft and is displaceable sidewardly to either drive the arm and spring legs upwardly or downwardly depending upon the direction of travel of the cam block.

Abstract: An ergonomic chair having a cooperatively adjustable knee support and seat is herein disclosed. The knee support and seat may be adjusted to position a user of the chair in a physiologic attitude that approaches the neutral position.

Abstract: A seating unit comprising a base configured to be positioned on a floor, a torsional energy unit connected to the base, a back connected to the torsional energy unit and a seat rotatably connected to the torsional energy unit. The torsional energy unit biases the back to a forward position. The torsional energy unit further limits angular rotation of the seat between a substantially horizontal seating position and a substantially vertical seating position.

Abstract: The invention provides a chair that the switching between operation and fixation of rocking may be operated with the height adjustment of the chair by one operation lever. A resilient member is interposed between a seat frame whose height is adjustable by a cylinder and a back frame rotatably fitted to the seat frame, wherein a joint member is rotatably fitted to the seat frame with a vertical shaft, an operation lever led to the outside of the seat frame and a pressing piece which touches and leaves a button for rod advancing and retreating of the cylinder are provided with a rocking member which is rockably assembled to the joint member with a horizontal shaft, and an interlocking regulating member is attached to an arm piece of the joint member so that the rotation of the back frame may be adjusted by moving the regulating member.

Abstract: A chair adjustable device includes a base with which a seat frame and a backrest frame are respectively and pivotably connected. A positioning mechanism is connected to the base and includes an operation handle which is able to shift a transmission frame and a positioning plate is movably connected to the transmission frame and biased by a spring, so that the positioning plate can be movably engaged with one of notches defined in a positioning member on the seat frame. The seat frame and the backrest frame are connected by a connection member so that the chair can be adjusted its tilt angle by operating the operation handle.

Abstract: The chair includes seat and back assemblies interconnected in a four-bar linkage. The chair further includes a tension mechanism comprising a coil spring projecting forwardly from a base and an adjustment linkage which is connected to said coil spring and to a front link of said four-bar linkage. A back linkage end of said adjustment linkage being axially movable along an axis of said coil spring and a front linkage end being vertically movable along said front link to adjust displacement of said adjustment linkage during rearward pivoting of said front link.

Abstract: Cushioning device to cushion a backrest with respect to the seat of a chair or suchlike. The device comprises a first supporting element connected to the backrest, a second supporting element connected to the seat and pinned to the first supporting element, and a spring connected both to the first supporting element and to the second supporting element, to allow a reciprocal elastic oscillation, of a determined amplitude, between the backrest, which can oscillate, and the seat, which remain still. In a wall of the first supporting element a lodging seat is provided to lodge, at least partially, the spring in such a manner that the longitudinal axis of the spring is substantially aligned with respect to the first supporting element.

Abstract: A working chair with adjustable backrest support pre-set tension is described, in which a swiveling backrest support is positioned on a seat part, the backrest support being prestressed against the back of the user with a manually adjustable pre-set tension of an energy storing device. The front end of the energy storing device is rotatably mounted on a free, swiveling end of a guide bar close to the seat edge, and the rear end of the energy storing device is coupled to a free, swiveling end of the backrest support at a contact point which is designed to be adjustable and detectable.

Abstract: A chair, in particular office chair, comprises a seat support with a front seat support part and a rear seat support part which is pivotable in relation thereto about a horizontal pivoting axis. An adjustable-length energy storing device, which is articulated to the seat support parts, serves for adjustment of the two seat support parts relative to each other. An interlocking mechanism is provided for locking the pivotability of the seat support parts relative to each other, the interlocking mechanism being designed for providing a plurality of positions of interlocking of the front seat support part relative to the rear seat support part. The seat support parts of the chair can therefore be interlocked in a selected position of interlocking, meeting a user's wishes. This helps put into practice a chair that offers improved ease and convenience of sitting.

Abstract: A support for tilting or synchronized chair is provided. The device includes a supporting frame, a mobile frame, an elastic member, a stiffness adjustment mechanism coupled with the elastic member, a locking mechanism for engaging the mobile frame with the supporting frame, and an actuation device for engaging and disengaging the locking mechanism. The actuation device includes a rocker arm and a return arm. The return arm is connected to the end of the rocker arm that the locking mechanism is attached. The rocker arm has at least two positions of stable equilibrium that are determined by the engagement or disengagement of the locking mechanism. An alternative embodiment includes an outer shell having first and second pins that are coupled with the backrest frame. The second pin may be positioned within a slot formed in the shell so that the backrest frame may move between upright and reclined positions.

Abstract: A tiltable chair including a housing, a back support pivotally attached to the housing about a first horizontal axis and a seat support pivotally attached to the housing about a second horizontal axis. A leaf spring includes a first end engaging the housing and a second end biasing the back support and seat support in an upward direction. A fulcrum member is moveably supported in the housing and engages a bottom surface of the spring intermediate the first and second ends of the spring.

Abstract: A seating unit includes a base, a seat, a back, and a control operably supporting the seat and the back on the base for movement between upright and recline positions. The control includes a spring providing a biasing supporting force to the back during recline, and further includes a booster mechanism for increasing the supporting force, and still further includes a stop member and a selector device for activating and deactivating the booster mechanism. The selector device is easily movable with a low effort that is independent from friction generated by internal components of the booster mechanism. The stop member is linearly slidably mounted atop a control housing for selectively engaging the booster mechanism and the link for movement between a disengaged position, a booster-engaged position, a partial-recline position, and a recline-prevented position.

Abstract: An apparatus for adjusting the inclination of a chair back is disposed on the chassis at the bottom of a cushion and pivotally coupled to the middle of a base at the upper end of chair legs. A control rod has its middle predetermined position pivotally coupled to the base. A positioning plate has a bolt at its top surface and is disposed at the rear end of the base. A resilient component is pivotally coupled such that one end of the resilient component is hooked into an end of the control rod, and the other end of the resilient component being hooked into the bolt at the top surface of the positioning plate. When the control rod is turned to swing its end, the resilient component rotates, so that one of the resilient legs of the resilient component produces an elastic push onto the positioning plate. Thus, the positioning plate contracts and moves to embed into or withdraw from a latch groove disposed at the bottom rear side of the chassis.

Abstract: A angle adjusting mechanism for a chair includes a support base, a seat support frame pivotally mounted on the support base, and an adjusting bar mounted between the support base and the seat support frame for adjusting an included angle between the support base and the seat support frame. Thus, the inclined angle of the seat support frame can be easily adjusted by pushing the adjusting bar, thereby facilitating the user adjusting the inclined angle of the chair.

Abstract: A seating unit includes a base, a seat, a back, and a control operably supporting the seat and the back on the base for movement between upright and recline positions. The control includes a spring providing a biasing supporting force to the back during recline, and further includes a booster mechanism capable of increasing the supporting force, and still further includes a selector device for activating and deactivating the booster mechanism. The selector device is easily moveable with a low effort that is separated from and independent from any friction generated by internal components of the booster mechanism. In a narrower aspect, the control is powered, such as by an electrical or electromechanical device from a remote location. A back stop is attached to the selector device, for movement between a disengaged position, a partial-recline position, and a recline-prevented position.

Abstract: This object is attained in a chair comprising a pedestal; a seat support supported thereon via a chair column, said seat support comprising a front and a rear seat support element being connected with one another via a pivot axis extending substantially horizontally; a seat supported on said seat support elements; a backrest secured on said rear seat support element; a longitudinally adjustable energy storing means for mutually adjusting said backrest and said seat, said energy storing means being joined with said seat support elements at a distance from their pivot axis; a spring abutment being arranged pivotably around said pivot axis for adjustably dampening a pivoting movement of said seat support elements relative to one another; an adjusting element extending substantially tangentially relative to said pivot axis and being pivotable around an adjusting element pivot axis for modifying the bias between said spring abutment and one seat support element; and an actuating twist handle connected with said ad

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

Abstract: A seating unit includes a seating unit having a base, a seat and a back operably pivoted to the base for synchronous movement including recline of the back and forward movement of the seat, an adjustable variable back stop adjustably engaging the seat for adjustably limiting a rearward tilt of the back, and a handle. The handle and the back stop are supported for independent movement, but are interconnected by a connecting mechanism including a pair of links so that the back stop is selectively adjusted upon rotation of the handle.

Abstract: It is provided for a reclining device for chairs and the chair with said reclining device, comprising an elastic element with linear strain (8) having a first end (8a) abutting against the primary body (2) of a chair, and a half-shell element (12) adapted to house at least a portion of the elastic element (8) starting from a second end (8b) of the latter, said half-shell element (12) having two abutment portions (12b) for a pair of pushing extensions (13) integral with the support element (4) of the reclining back.

Abstract: A damper (20) for damping motion between two relatively moveable members, such as pivotal motion between components in office chairs (10). The damper (20) includes a outer member (22) having an internal recess (23) with a inner surface (24) and a crosswise oriented hole (30) intersecting the recess (23), and an inner member assembly (32) moveable relative to the outer member (22) having a shaft (34) with a resilient friction member (38) mounted thereon. The resilient friction member (38) frictionally engages the inner surface (24) in an interference fit relationship thereby radially precompressing the resilient friction member (38). The resilient friction member (38) preferably has one or more protrusions (40) that may be axially or radially oriented.

Abstract: A chair back upright tilts about a pivot axis with respect to a chair seat plate and has a protrusion on the bottom portion thereof. When the occupant of a chair reclines, the protrusion on the back upright and a stop plate make contact with each other. The contact stops the tilting of the back upright. A lever handle, fixedly attached to the stop plate, can be rotated thereby providing more or less tilting of the back upright before contact between the protrusion and the stop plate occurs.

Abstract: A chair control providing both articulating tilt motion and dual-ratio, adjustable, synchronized tilt motion. In a first aspect, the control can be configured as either an articulating tilt control or a synchronized tilt control. In a second aspect, the angle between the seat and the backrest may be selected by the user when the control is configured for either the articulating mode or the synchronized mode. In a third aspect, when in the synchronized mode, the angle between the seat and the backrest increases during forward tilt action to avoid “clam shelling.” In a fourth aspect, a forward tilt selector enables or prohibits forward tilting of the control.

Abstract: A backrest adjustment device has a hollow base seat, an oblong panel, a guide mount, a slide seat, a nut, a coiled spring, a compression spring, a positioning plate, a top panel, a screw rod, and a control rod. The positioning plate has a threaded aperture. The guide mount is disposed on the oblong panel. The guide mount has a bottom recess and an oblong hole. The positioning plate is inserted in the bottom recess of the oblong panel. The slide seat has a bottom groove, a slant slot, and a lateral lug. The screw rod has a disk head. The top panel has a plurality of click serrations. The top panel engages with the hollow base seat. The control rod has an oval plate, an extension bar, and a plurality of annular grooves. The screw rod passes through the compression spring, the lateral lug, the coiled spring, the nut, and the oval plate. The extension bar is disposed between the top panel and the hollow base seat.

Abstract: A locking unit includes a frame to permit extension of a bolt. An upper portion of a bracket is pivoted to left and right side walls of the frame. A linking member has a rear part connected to the bracket, and a front part formed with an arcuate slot through which the bolt extends. A stationary clamping seat is fixed on the right side wall. A movable clamping member is mounted on the bolt. An operating lever is pivoted to a C-shaped connector about a first pivot, and is pivoted to the right side wall about a second pivot. When the bolt is moved to a locking position, the linking member counteracts the clamping force, which results in a pulling force that pulls the C-shaped connector in a direction toward the left side wall along a horizontal line defined by the bolt and the operating lever is prevented from being turned upwardly by the pulling force.

Abstract: A tilt control is provided in an office chair to operatively connect tiltable seat and back assemblies. The tilt control permits both forward and rearward tilting of the seat and back assemblies and includes a tilt lock mechanism and a single actuator for selectively locking out forward and/or rearward tilting. In particular, the actuator has a handle which moves along a single path passing through first to third operative positions. In this regard: the first operative position locks out both forward and rearward tilting in any of a plurality of tilt positions; the second operative position locks out forward tilting but permits rearward tilting; and the third operative position permits both forward and rearward tilting.

Abstract: A synchronous tilt control mechanism is provided for a chair. The chair includes a base, a seat, a back, a torsion spring, a first slide member and a second slide member. The base further includes a tilt control housing mounted thereon. The back includes a forwardly extending support member. The seat and back are pivotally attached to the tilt control housing. The torsion spring has a forwardly extending leg and a rearwardly extending leg. The forwardly extending leg is mounted to the tilt control housing. The seat slidably engages the support member by way of the first slide member, which is disposed on one of the seat and the support member. The support member slidably engages the rearwardly extending leg of the torsion spring by way of the second slide member, which is disposed on one of the support member and rearwardly extending leg. A downward movement of the seat causes the back to move downwardly and rearwardly against an upward force provided by the torsion spring.

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

Abstract: A tiltable chair including a housing, a back support pivotally attached to the housing about a first horizontal axis and a seat support pivotally attached to the housing about a second horizontal axis. A leaf spring includes a first end engaging the housing and a second end biasing the back support and seat support in an upward direction. A fulcrum member is moveably supported in the housing and engages a bottom surface of the spring intermediate the first and second ends of the spring. The chair also include an adjustable backrest and armrests slideably mounted on the back support, and a seat slideably mounted on the seat support. A tilt limiter is provided to limit the rearward tilting of the chair. A selector member includes indicia that indicates the setting of the tilt limiter so as to apprise the user of maximum available rearward tilt position of the chair.

Abstract: A tilt control mechanism for an office chair includes a spring arrangement which permits forward and rearward tilting of the chair while also urging the chair to a normal upright position. The spring arrangement includes front and rear springs which act in combination such that the upward acting forces acting on the chair can be varied during use. The forces being applied by the front spring are adjusted by a side-actuated tension adjustment mechanism which incorporates a wedge block for adjusting the spring forces. Further, the rear springs provide a variable spring force such that the spring force is maximized when in the normal position but is decreased substantially once the chair is fully reclined. This reduction in spring force allows a user to maintain the chair in the fully reclined position with significantly less force than was required to tilt the chair rearwardly while a sufficient spring force continues to be applied by the front spring to urge the chair to the normal position.

Abstract: An office chair is provided. The office chair includes an eccentric adjustment of the tilt of the seat surface. In order to prevent against undesired tilt adjustments, it is provided to use a rotating shaft with a manipulation part and a functional part for the eccentric adjustment and to control a disengageable locking catch, which blocks any rotating angle adjustment of the functional part of the rotating shaft in the non-disengaged state by the manipulation part in a first rotating angle region.

Abstract: A chair includes a base, a backrest supported by the base, a seat support by the base, and a seat slidably mounted to the seat support. A seat adjustment device can be employed to allow for forward and rearward adjustment of the seat relative to the backrest.

Abstract: A tiltable chair including a housing, a back support pivotally attached to the housing about a first horizontal axis and a seat support pivotally attached to the housing about a second horizontal axis. A leaf spring includes a first end engaging the housing and a second end biasing the back support and seat support in an upward direction. A fulcrum member is moveably supported in the housing and engages a bottom surface of the spring intermediate the first and second ends of the spring. The chair also include an adjustable backrest and armrests slideably mounted on the back support, and a seat slideably mounted on the seat support. A tilt limiter is provided to limit the rearward tilting of the chair. A selector member includes indicia that indicates the setting of the tilt limiter so as to apprise the user of maximum available rearward tilt position of the chair.

Abstract: An office chair has a seat (1) mounted on a base (2) so that its inclination can be adjusted with a mechanism (4). The mechanism has a spring (28) mounted in compression between the seat and base, and a manual control (20) acts to adjust the extent of compression of the spring and also the direction of application of the spring force so that a generally linear resistance characteristic can be obtained. The spring (28) preferably has a lower support (12) which engages a positionally adjustable fulcrum (15, 18), and an upper support (11) pivotally connected to the lower support (12). The upper support (11) may be rigidly connected via a rigid bar to a chair back (3). A spring and ratchet arrangement (33, 34) may be provided for locking the seat in position relative to the base.

Abstract: A chair tilt control mechanism includes an actuator handle for locking and unlocking the tilt control mechanism. The actuator handle is a self-contained assembly which is readily mountable to the chair, and includes a hollow housing and a rotatable shaft which is rotatably supported on the housing. The housing includes a V-shaped camming surface and the shaft includes a radial projection which slides axially and circumferentially along the camming surface to positively define locked and unlocked position for actuator handle. The radial projection also defines a stop which allows assembly of the housing and shaft together without fasteners while preventing disassembly when engaged with the camming surface.