Abstract: A chair includes a base, a support element and a torsion element. The support element is coupled to the base and includes a seat region, a backrest region and a transition region connecting the seat region and the backrest region. The backrest region is reclinable relative to the seat region by way of elastic deformation of the support element. The torsion element is coupled to the base and to the backrest region. The torsion element controls the reclining of the backrest region relative to the seat region. The support element is exclusively connected to the torsion element above a lumbar region, wherein the backrest region can be inclined and/or twisted in relation to the seat region.

Abstract: A structure-improved multifunction chassis includes a chassis base, a handle and a plurality of pull lines, wherein the chassis base includes a backrest angle adjustment device, a cushion height adjustment device, and a cushion back-and-forth moving device. The chassis base is pivotally connected with a left and right connecting rod of a seat backrest frame. The handle includes a shift arm, a handle fixed block, and a handle base. The handle fixing block is installed in the handle base and is able to swing up and down. The handle fixing block is mounted on the handle base by bolts. One handle controls three pull lines at the same time, and the user adjusts the angle of the backrest, cushion lifting or moving back and forth by operating the handle.

Abstract: A pneumatic fore-aft vibration isolator lock system (and method) is provided. The innovation provides a locking action through the use of pneumatically-actuated spring pressure to lock or unlock the isolation system. In one aspect, to unlock, air pressure is applied and the spring pressure is overridden by the air pressure. By overriding the spring pressure, plates are moved thereby unlocking the isolator. The system can allow for one touch, fingertip locking and unlocking of the fore/aft isolation system.

Abstract: A tilt mechanism is configured for adjustment of a tension applied by a chair back. The tilt mechanism includes a base, a back bracket tiltably supported on the base, and a rocker coupled to the back bracket so as to be moveable relative to the back bracket. The rocker has a pivot axis and pivots about the pivot axis when the back bracket tilts relative to the base. An energy storage mechanism is coupled to the rocker to exert a force onto a portion of the rocker. An actuating mechanism is coupled to at least one of the rocker or the energy storage mechanism and is configured to alter a distance between the pivot axis and the portion of the rocker at which the force is exerted onto the rocker, thereby altering a length of a lever arm.

Abstract: An office chair mechanism provided with a device for adjusting the swivel force includes a fixed part secured to the chair base, movable parts secured to the seating portion and to the back rest (22) of the chair, and an elastic element which opposes the weight of the chair user, a lever having contact surfaces which interact with said fixed part by means of a fulcrum having a movable contact element interposed between the end acting on the elastic element and the other end to which the movable parts are pivoted, and an adjustment element which causes only the movable contact element to move but without modifying the position of the elastic element and of the lever.

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: 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 preference control mechanism is provided that includes a housing, a shuttle, a sub shuttle and at least one resilient member. The housing has a channel. The shuttle has a cavity. The shuttle is moveable within the channel of the housing from a first position to at least one second position. The sub shuttle is moveable within the channel of the housing and is moveable independent of the shuttle. The one or more resilient members have a first end and a second end opposite the first end. The first end is attached to the shuttle and the second end is attached to the sub shuttle. The preference control mechanism is configured for attachment to at least one chair component. Chairs may also be designed to include one or more embodiments of the preference control mechanism.

Abstract: An adjustable reclining chair including a seat configured to support a user, a chair back, a base and a control mechanism mounted on the base. The control mechanism coupling the chair back to the seat with the chair back located generally adjacent to the user's back when the user is seated upon the seat. The control mechanism including a resistance adjustment mechanism for varying the control mechanism's resistance to a reclining force applied by the user to the chair back in order to move the chair back rearward from an upright position. The resistance adjustment mechanism activated by the weight of the user when seated in the chair, such that easy adjustment of the resistance is facilitated with the chair in an upright position. The resistance adjustment mechanism including a resilient member placed under a load during reclining of the chair to provide resistance to the reclining force.

Abstract: A preference control mechanism is provided that includes a housing, a shuttle, a sub shuttle and at least one resilient member. The housing has a channel. The shuttle has a cavity. The shuttle is moveable within the channel of the housing from a first position to at least one second position. The sub shuttle is moveable within the channel of the housing and is moveable independent of the shuttle. The one or more resilient members have a first end and a second end opposite the first end. The first end is attached to the shuttle and the second end is attached to the sub shuttle. The preference control mechanism is configured for attachment to at least one chair component. Chairs may also be designed to include one or more embodiments of the preference control mechanism.

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: The invention relates to a chair with a seat, a base support and a backrest, wherein the seat is pivotably mounted on the base support and the backrest is pivotably mounted on the seat, and a first spring system is provided between the base support and the seat and a second spring system is provided between the seat and the backrest. Furthermore, means are provided for adjusting the spring behavior of the two spring systems so that the pivotability of the seat in relation to the base support and the pivotability of the backrest in relation to the seat can be adapted to different requirements, especially to users of different weights.

Abstract: A body support structure, such as a piece of furniture, in particular a piece of furniture for sitting on or a piece of furniture for lying on, such as, for example, chair, armchair, stool, bed or sofa, a seat of the piece of furniture being supported by a spring mechanism, and the spring mechanism being capable of being set to a weight force with which a person acts on the 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: An adjustable reclining chair including a seat configured to support a user, a chair back, a base and a control mechanism mounted on the base. The control mechanism coupling the chair back to the seat with the chair back located generally adjacent to the user's back when the user is seated upon the seat. The control mechanism including a resistance adjustment mechanism for varying the control mechanism's resistance to a reclining force applied by the user to the chair back in order to move the chair back rearward from an upright position. The resistance adjustment mechanism activated by the weight of the user when seated in the chair, such that easy adjustment of the resistance is facilitated with the chair in an upright position. The resistance adjustment mechanism including a resilient member placed under a load during reclining of the chair to provide resistance to the reclining force.

Abstract: A permanent-contact mechanism for an office chair or the like is formed as a comparatively flat permanent-contact mechanism with a seat frame, which can be positioned on a chair upright, with a backrest support, which is arranged on the seat frame such that it can be pivoted about a transverse axis, and with at least one spring-activated or inherently resilient lever element, which interacts with the backrest support such that the backrest support is always pivoted counter to a spring force. The position of the point of rotation of the lever element differs from the position of the transverse axis.

Abstract: A device for adjusting the reclining force in office chair mechanisms comprising at least two mutually hinged parts and elastic means (16) which maintain said parts elastically spaced apart, said device being characterized by comprising:—at least two levers (7, 6), at least one of which interacts with said elastic means (16) and the other of which is connected to one of said hinged parts, said levers respectively interacting via at least one movable contact element (13) by way of contact surfaces,—means (9, 10, 14) for adjusting the position of said movable contact element (13) such as to modify the points at which said movable contact element bears on said contact surfaces and consequently such as to modify the lever arms.

Abstract: The invention relates to a back rest for a stool or a chair, comprising two adjacent, spring-mounted back supports (3.1), each of which is fixed to a separate carrier part (4.1). Said back rest is characterised in that each carrier part (4.1) forms the first limb of an essentially L-shaped carrier (4), and the second limb (4.2) of each carrier (4) is fixed beneath the stool or chair seat in such a way that it can be pivoted about a horizontal axis against an elastic force.

Abstract: According to the present invention, a control system for a chair is provided. The control system is comprised of first and second resilient blocks, first and second stabilizing members and first and second rockers. The first stabilizing member has first and second ends and defines a first horizontal axis. The first end of the first stabilizing member extends into the first resilient block and the second end of the first stabilizing member extends into the second resilient block. The second stabilizing member is coupled to the first stabilizing member by a connector. The second stabilizing member has first and second ends and defines a second horizontal axis disposed in parallel to the first horizontal axis. The first end of the second stabilizing member is operably coupled to the first rocker, and the second end of the second stabilizing member is operably coupled to the second rocker.

Abstract: An adjustable reclining chair including a seat configured to support a user, a chair back, a base and a control mechanism mounted on the base. The control mechanism coupling the chair back to the seat with the chair back located generally adjacent to the user's back when the user is seated upon the seat. The control mechanism including a resistance adjustment mechanism for varying the control mechanism's resistance to a reclining force applied by the user to the chair back in order to move the chair back rearward from an upright position. The resistance adjustment mechanism activated by the weight of the user when seated in the chair, such that easy adjustment of the resistance is facilitated with the chair in an upright position. The resistance adjustment mechanism including a resilient member placed under a load during reclining of the chair to provide resistance to the reclining force.

Abstract: A task chair capable of forward and rearward synchronized movement with a base assembly, a linkage supported by the base assembly to pivot about an axis in relation to the base assembly, a seat assembly pivotally retained relative to the linkage, and a back assembly pivotally retained relative to the linkage. The linkage can include a bracket and a resiliently deflectable assembly retained relative to the bracket. A projection retained by the base assembly can engage the resiliently deflectable assembly whereby the linkage and the seat and back assemblies can pivot in relation to the base assembly. The linkage can have a bracket; a first link pivotally coupled at a first axis relative to the bracket, pivotally coupled at a second pivot axis relative to the seat assembly, pivotally coupled at a third pivot axis relative to the back assembly; and a second link pivotally coupled at a first axis relative to the bracket and at a second axis relative to the back assembly.

Abstract: A pivoting joint for use in a task chair or the like provides an adjustable elastomeric coupling that permits multi-axis rocking of the seat pan with a restoring force that provides controlled stability.

Abstract: A chair having an automatically adjusting resistance to tilt. The chair includes a back support, a frame, a base and a back pivot member, which is pivotally mounted to the frame, and a seat, which is also pivotally mounted to the frame, such that an occupant of the chair adjusts resistance to tilt or reclining of the chair by applying a rearward force to the back support.

Abstract: It is a subject to provide a chair capable of realizing a condition in which movements of a seating person are preferably followed and a condition in which a back of the seating person can be preferably supported. For this purpose, a chair C comprising a lower frame portion that is supported to be rockable between a standing position and a rearward tilting position of a back frame with respect to the base and an upper frame portion that is supported to be rockable between a normal position and a rear end position, wherein the chair is further comprised with a movement range setting mechanism with which a movement range through the rocking movement of the upper frame portion with respect to the lower frame portion is made changeable in accordance with the position of the lower frame portion with respect to the base during the rocking movement.

Abstract: A preference control mechanism is provided that includes a housing, a shuttle, a sub shuttle and at least one resilient member. The housing has a channel. The shuttle has a cavity. The shuttle is moveable within the channel of the housing from a first position to at least one second position. The sub shuttle is moveable within the channel of the housing and is moveable independent of the shuttle. The one or more resilient members have a first end and a second end opposite the first end. The first end is attached to the shuttle and the second end is attached to the sub shuttle. The preference control mechanism is configured for attachment to at least one chair component. Chairs may also be designed to include one or more embodiments of the preference control mechanism.

Abstract: A device for adjusting the reclining force in office chair mechanisms comprising at least two mutually hinged parts and elastic means (16) which maintain said parts elastically spaced apart, said device being characterised by comprising:—at least two levers (7, 6), at least one of which interacts with said elastic means (16) and the other of which is connected to one of said hinged parts, said levers respectively interacting via at least one movable contact element (13) by way of contact surfaces,—means (9, 10, 14) for adjusting the position of said movable contact element (13) such as to modify the points at which said movable contact element bears on said contact surfaces and consequently such as to modify the lever arms.

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 synchronous office chair comprising a support (1) firmly connected with a supporting column, a seat base (2) articulated on a tilting axis (4) support with a flange (5) and a backrest (3) with a back bracket (6). The back bracket (6) features a first, second and third cam tracks (7, 8, and 9) and engages in an interstice between support (1) and seat base (2). Said seat base (2) with flange (5) and backrest (3) with back bracket (6) are formed to execute a synchronous movement. A first roller bearing (10) is mounted on flange (5) of seat base (2) that engages in the first cam track (7) of back bracket (6) and in which the synchronous movement is guided in first cam track (7). A second roller bearing 11 is mounted on seat base (2) that engages in second cam track (8) of back bracket (6) and in which synchronous movement is guided in second cam track (8).

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 tiltable chair including a base, a fulcrum member having a curved support surface, a back support pivotally connected to the base at a pivot axis and pivotable between at least an upright position and a rearward tilt position, and at least one leaf spring having first and second ends, with the first end being restrained by the base. The at least one leaf spring engages the curved support surface of the fulcrum member at a first contact point when the back support is in the upright position and at a second contact point when the back support is in the rearward tilt position, wherein the second contact point is positioned rearwardly on the at least one leaf spring relative to the first contact point. A link member is pivotally connected to the back support at a first pivot location and is pivotally connected to the at least one leaf spring at a second pivot location. The link member defines a vector between the first and second pivot locations and the first pivot location and the pivot axis define a plane.

Abstract: A locking device in an office chair structure of the type with articulation permitting the movement of the adjustable seat and seat back, with a mobile base from which a column rises, which is adjustable in height, and which supports a seat plane and a hinged seat back. The structure of the office chair includes a seat, attached at the front to the corresponding front side of a central support body secured to the top of the adjustable column along the vertical axis; a central support body, which, at the back, keeps in place the lower ends of the two support uprights of the armrests and a seat back connected to the seat, swinging and linked, near to the back part, to the central support body by means of a compression spring; Coaxially to the compression spring, there is a rod, one side of which is integral with the back rest, while the other side is axially mobile with respect to a static connecting body linked to the central support body of the chair.

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: 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 tiltable chair including a base, a fulcrum member having a curved support surface, a back support pivotally connected to the base at a pivot axis and pivotable between at least an upright position and a rearward tilt position, and at least one leaf spring having first and second ends, with the first end being restrained by the base. The at least one leaf spring engages the curved support surface of the fulcrum member at a first contact point when the back support is in the upright position and at a second contact point when the back support is in the rearward tilt position, wherein the second contact point is positioned rearwardly on the at least one leaf spring relative to the first contact point. A link member is pivotally connected to the back support at a first pivot location and is pivotally connected to the at least one leaf spring at a second pivot location. The link member defines a vector between the first and second pivot locations and the first pivot location and the pivot axis define a plane.

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

Abstract: An adjustable armrest for a chair includes a housing having a cavity defined by a wall and a latch member slideably mounted in the cavity. The latch member includes a wedge shaped portion having a first and second surface forming a oblique angle between them. One of the first and second surfaces engages the wall of the housing at least when the latch is in the engaged position.

Abstract: The invention relates to seat and backrest arrangements in seat furniture, in particular office chairs, which comprise a seat plate, a seat-plate support and a backrest support and in which the seat plate (1), in the region of its front, knee-side edge (2), is connected moveably to the seat-plate support (3) and, in the region of its rear edge (5), is connected moveably to the backrest support (6), the backrest support (6) being coupled displaceably to the seat-plate support (3). The seat and backrest arrangements according to the invention are characterized in that a spring means (4) for cushioning the seat plate (1) and the backrest support (6) is arranged in the region of the front, knee-side edge (2) of the seat plate (1)—between the seat plate (1) and seat-plate support (3).

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 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 back construction for a seating unit includes a back frame, and a compliant back having a forwardly-protruding lumbar support section that is characteristically flexible and bendable, such that the compliant back can be flexed to a plurality of different convex shapes. Top and bottom connections pivotally connect the compliant back to the back frame. An adjustable force-generating mechanism is operably attached to at least one of the compliant back and the back frame. The force-generating mechanism is constructed to provide an adjustable biasing force that adjustably biases the lumbar support section forwardly for optimal lumbar support for a seated user's back, but the force-generating mechanism characteristically provides the biasing force without forcing a shape change in the compliant back. A vertically adjustable lumbar support is slidably attached to the back shell.

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

Abstract: A 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 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 includes a tilt control mechanism which connects a seat assembly to a base. The tilt control mechanism defines a pivot connection between the seat assembly and the base whereby the seat assembly effectively pivots about a pivot point in any direction extending radially from the pivot point. The tilt control mechanism includes an annular elastomeric ring which resists multi-directional tilting and biases the seat assembly to a neutral position. The elastomeric ring is adjustable axially toward and away from the pivot point to adjust resistance to tilting.

Abstract: An office chair includes a tilt control mechanism which connects a seat assembly to a base. The tilt control mechanism defines a pivot connection between the seat assembly and the base whereby the seat assembly effectively pivots about a pivot point in any direction extending radially from the pivot point. The tilt control mechanism includes an annular elastomeric ring which resists multi-directional tilting and biases the seat assembly to a neutral position. The elastomeric ring has a contact area on which the tilting moment of the seat assembly acts which contact area can be selectively varied to adjust tilting resistance.