A chair assembly includes a seat support structure, a back support structure, a back tensioning assembly adjustable between low and high tension positions, an actuator assembly adapted to adjust the back tensioning assembly between the low and high tension positions, a control input assembly actuable by rotating the portion of the control input assembly, and a control link assembly operably coupling the control input assembly with the actuator assembly to adjust the back tensioning assembly between the low and high tension positions upon rotation of the portion of the control assembly by a seated user, wherein a number of rotations of the portion of the control input assembly is not limited by the control link.

A seating unit component assembly comprises a support component that includes a first surface adapted to abut a seated user, a second surface opposite the first surface, a first end surface, a second end surface opposite the first end surface, and a pair of side surfaces extending between the first and second end surfaces, and a cover having a plurality of sides that cooperate to form an interior space that receives the support component therein, wherein the cover includes a first portion comprising a non-fabric substantially flexible thermoplastic material covering at least a portion of at least one of the side surfaces of the support component, a second portion comprising a fabric covering at least a portion of the first surface and at least a portion of the first end surface of the support component, and a third portion comprising a substantially rigid overlay covering at least a portion of the second end surface and at least a portion of the second surface.

In an aspect, the invention is directed to a chair that has a pedestal and an upper assembly including a body support assembly and a tilt control assembly. A biasing member is provided to bias the body support assembly towards an unreclined position. When the chair is empty the biasing member has a certain preload. When a person sits in the chair or when a downward force is applied to the upper assembly, there is relative movement between two chair components which causes an increase in the preload in the biasing member as compared to the preload when the chair is empty. As the downward force on the upper assembly increases, the preload in the biasing member increases.

A seating unit component assembly comprises a support component that includes a first surface adapted to abut a seated user, a second surface opposite the first surface, a first end surface, a second end surface opposite the first end surface, and a pair of side surfaces extending between the first and second end surfaces, and a cover having a plurality of sides that cooperate to form an interior space that receives the support component therein, wherein the cover includes a first portion comprising a non-fabric substantially flexible thermoplastic material covering at least a portion of at least one of the side surfaces of the support component, a second portion comprising a fabric covering at least a portion of the first surface and at least a portion of the first end surface of the support component, and a third portion comprising a substantially rigid overlay covering at least a portion of the second end surface and at least a portion of the second surface.

A chair assembly includes a base assembly, a seat assembly having a pair of side edges and a fore-to-aft extending longitudinal centerline, a back assembly movable between upright and reclined positions, and an arm assembly including an arm base extending from a first location between the side edges to a second location laterally outward of one of the side edges, wherein the arm base extends at an acute angle with respect to the longitudinal centerline and at an upward angle from the first location toward the second location, a support assembly supported by and extending upwardly from the arm base, and an armrest supported by the support assembly that is adjustable to support the armrest between a plurality of selected vertical positions, wherein the arm assembly and back assembly move at a different rate from one another as the back assembly is moved between the upright and reclined positions.

A chair assembly includes a base assembly, a seat assembly having a pair of side edges and a fore-to-aft extending longitudinal centerline, a back assembly movable between upright and reclined positions, and an arm assembly including an arm base extending from a first location between the side edges to a second location laterally outward of one of the side edges, wherein the arm base extends at an acute angle with respect to the longitudinal centerline and at an upward angle from the first location toward the second location, a support assembly supported by and extending upwardly from the arm base, and an armrest supported by the support assembly that is adjustable to support the armrest between a plurality of selected vertical positions, wherein the arm assembly and back assembly move at a different rate from one another as the back assembly is moved between the upright and reclined positions.

A tilt mechanism for a chair comprises a base, a first support configured to support a chair seat and a second support configured to support a chair back, the second support is pivotably coupled to the base. A coupling mechanism couples the second support to both the base and the first support. The coupling mechanism comprises a pin attached to the first support, a first linear guide slot provided on the base, and a second linear guide slot provided on the second support. The pin is slideably received in both the first linear guide slot and the second linear guide slot. The second linear guide slot slopes upwardly in a forward direction of the tilt mechanism when the tilt mechanism is in a zero-tilt position.

A posture holding apparatus including, a base onto which a substance is placed, a supporting member being attached onto the base so that the supporting member swings between a standby state and an active state, and a swinging support member having a returning force for returning the supporting member to the standby state, wherein the swinging support member is structured by a swinging member, a biasing member for applying a biasing force to the swinging member to the standby state, a liquid pressure output member for outputting liquid pressure in response to a weight of the substance, and a displacement amount adjusting member, with which a point of action of the biasing force applied from the biasing member to the supporting member is moved in response to the liquid pressure such that a distance from the pivot to the point of action changes.

A device for synchronizing the tilt of the backrest and of the seat of a chair, of the type having a frame of the backrest, a frame of the seat and a support integral with the base of the chair, as well as a first crank, integral with the backrest frame, and hinged in the rear portion of the seat frame and the support, and at least one second crank hinged in the front portion of the seat frame and to the support. The first crank and the second crank (5) form, together with the seat frame, a four-bar linkage. An adjusting lever is constrained to the four-bar linkage and is further operatively connected to a movable fulcrum and elastic means.

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.