Abstract: A chair that provides movement side-to-side about a first pivot axis positioned above the seat plane allows the user a wide range of dynamic movement, but does not require constant or excessive action on the part of the user to maintain a desired position. In addition and concurrently thereto, the structure may include a second pivot that is also positioned above the seat plane and that provides forward-and-back movement of the seat. The first and second pivot axes can be engaged synchronously or independently by the user as desired delivering infinite degrees of angles of movement. Said pivot axes are more closely adjacent to the human body pivot joints and axes. The seat and seat back may be joined together to a central spine frame that moves about the second pivot, thereby maintaining the seatback position and seat position relative to each other during forward-and-back movement of the spine along the second pivot.

Abstract: A seat guiding apparatus for a chair includes a base, an elastic assembly mounted in the front end of the base and having a torsion spring and a moveable plate abutted against the torsion spring, and a seat assembly provided with a seat and a bracket connected with the seat. The bracket of the seat assembly has a front end connected with the moveable plate and a rear end movably mounted in curved guiding grooves of the base, such that the seat assembly is moveable along the curved guiding grooves relative to the base. As a result, when sitting on the seat, a sitter' back can be guided by the movement of the seat assembly to lean against a backrest of the chair for support.

Abstract: A chair assembly has a base frame, a pivot frame, a backrest frame, a seat frame and a backrest-adjusting device. The pivot frame is mounted pivotally on the base frame. The backrest frame is mounted securely on the pivot frame. The backrest-adjusting device is mounted between the base frame and the pivot frame and has a torsion spring biasing the pivot frame and the backrest frame to pivot forward. The backrest-adjusting device tightens or loosens the torsion spring to change the resilient force provided to the backrest frame against users' back. Therefore, the chair assembly adapts to differ users well.

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 seat comprising a seat pan (12) and a support structure, wherein the seat pan (12) is pivotally coupled to the support structure (8) about a first pivot axis (pi) provided across substantially the front of the seat pan (12), such that the seat pan (12) may be pivoted about the said first pivot axis (pi) in use, and the angle of the seat pan (12) relative to the support structure (18) may thus be adjusted. The seat further comprises a backrest (14), the backrest being coupled (p2) to substantially the rear of the seat pan (p12). Also provided is pneumatic apparatus for use with a seat, comprising one or more inflatable cushions for supporting a user in use.

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 chair assembly has a base frame, a pivot frame, a backrest frame, a seat frame and a backrest-adjusting device. The pivot frame is mounted pivotally on the base frame. The backrest frame is mounted securely on the pivot frame. The backrest-adjusting device is mounted between the base frame and the pivot frame and has a torsion spring biasing the pivot frame and the backrest frame to pivot forward. The backrest-adjusting device tightens or loosens the torsion spring to change the resilient force provided to the backrest frame against users' back. Therefore, the chair assembly adapts to differ users well.

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 back rest tilting device in a reclining chair formed of fewer parts. A force promoting unit energizes a back rest in an upright direction. A rotating force promoting unit with rubber torsion springs includes a laterally extending pivot shaft rotated integrally with the back rest and an elastic body filled between an outer tube locked to a support body coaxially with the core and the pivot shaft so that the elastic body is elastically deformed when the pivot shaft is rotated about the center axis of the outer tube to impart a returning rotating force to the pivot shaft.

Abstract: A tilt tension mechanism for a chair comprises a gear drive mechanism for driving a torsion bar having a drive shaft, a face gear and an actuator shaft with a pinion gear section. The pinion gear section and face gear have cooperating spiral threads which provide for multi-teeth engagement. An isolator bearing is disposed adjacent to the engagement section between said pinion gear teeth and said face gear teeth to support vertical tooth loads.

Abstract: A task chair, including a backrest assembly and a seat assembly pivotally coupled both to one another and to side portions of a fixed yoke member for synchronized movement, in which the seat of the seat assembly moves upwardly and forwardly concurrently with recline of the backrest of the backrest assembly. The chair further includes a tension assembly including an elongate tension member, such as a leaf spring, secured at one end thereof to the yoke member, and a contact member, such as a contact roller, adjustably mounted to the seat assembly. The contact member engages the tension member such that the tension member resists recline of the backrest assembly and concurrent movement of the seat assembly from their initial positions, and also provides a restoring force which tends to move the backrest to its initial upright position and the seat to its initial rearward and lowered position.

Abstract: This invention provides a spring assembly for use in a chair tilt control mechanism. The tilt control mechanism is one that can recline and return a backrest for a chair. The spring assembly includes a cylindrical block that has first and second ends and a central bore. A pair of end caps is located at each of the first and second ends of the block. Each end cap has a receiving section that can rotate within the central bore of the block. Each end cap also has a hole extending through it that provides a coupling point for the chair backrest. The spring assembly also includes at least one steel coil spring around the block. The spring has one terminal end coupled to the tilt control mechanism and the other end coupled to one of the end caps. The end caps rotate within the block as the chair backrest is reclined or returned. The force needed to rotate the end caps is a sum of the spring force provided by the spring and the frictional relationship between the block and the end caps.

Abstract: An improved tilt rate control mechanism for a tilt back chair has an adjustable torsion spring, a tilt rate adjustment actuator and an actuator movement mechanism. The torsion spring has an adjustment lever for adjusting the tension on the torsion spring. The tilt rate adjustment actuator is disposed in contact with the adjustment lever such that the movement of the adjustment actuator causes movement of the adjustment lever. The adjustment actuator is moveable between (i) a first actuator position wherein the actuator is proximal to the torsion spring and the adjustment lever is in a minimum tension position, and (ii) a second actuator position wherein the actuator is distal from the torsion spring and the adjustment lever is in a maximum tension position.

Abstract: A tilt assembly comprising a tilt housing, a body support member pivotally attached to said tilt housing about a first horizontal axis and a spring mounted to said tilt housing at a second horizontal axis. The body support member is moveable between a first and second position. The second horizontal axis is adjustably moveable relative to the first horizontal axis. The spring biases said body support member at a first location when the body support member is in the first position and at a second location when the body support member is in the second position, with the second location being a greater distance from the first horizontal axis than the first location. A method for supporting a chair body support member is also provided.

Abstract: Tilting seat chair, comprising: a base structure (16) bearing a transverse tilting axis (24), a seat support structure (14), tiltably mounted about the transverse tilting axis (24), an elastic arrangement for opposing the seat tilting motion, and an adjustment device (42) for varying the force opposing the elastic arrangement. The aforesaid elastic arrangement comprises a torsion bar (32) connecting the seat support structure (14) to the base structure (16) in a tilting manner about the transverse tilting axis (24). The torsion bar (32) has at least a first portion (32a) rotatably connected to the seat support structure (14) and at least a second portion (32b) connected to the base structure (16) through the aforesaid adjustment device.

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 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: A four legged or sled chair having a reclinable seat comprising a frame structure, a seat mounted within the frame structure for pivoting about a transverse torsion bar(s) axis, and elastic stops defining said seat position of maximum rearward pivoting and the position of maximum forward pivoting in relation thereto.