Abstract: 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.

Abstract: A chair includes a base structure, a seat support structure, a back frame comprising a front surface, a rear surface and a forwardly extending bottom portion pivotably connected to the base, a biasing member biasing the back frame from a reclined position toward an upright position, wherein the biasing member is located entirely forward a rearward most edge of the seat support structure, and a back shell comprising a forwardly extending bottom portion connected to the seat support structure, a front surface, a rear surface positioned in front of the front surface of the back frame, a pair of laterally spaced side portions defining an opening therebetween, and a top portion extending laterally between and connected to the side portions, wherein each of the side portions are exclusively connected to the back frame at a first location.

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 chair includes a base structure, a seat support structure, a back frame comprising a front surface, a rear surface and a forwardly extending bottom portion pivotably connected to the base, a biasing member biasing the back frame from a reclined position toward an upright position, wherein the biasing member is located entirely forward a rearward most edge of the seat support structure, and a back shell comprising a forwardly extending bottom portion connected to the seat support structure, a front surface, a rear surface positioned in front of the front surface of the back frame, a pair of laterally spaced side portions defining an opening therebetween, and a top portion extending laterally between and connected to the side portions, wherein each of the side portions are exclusively connected to the back frame at a first location.

Abstract: A chair back assembly includes a back frame having a front surface and a rear surface and including a laterally extending cross member having opposite end portions, a back shell including a front surface, a rear surface positioned in front of the front surface of the back frame, a pair of laterally spaced side portions defining an opening therebetween, and a top portion extending laterally between and connected to the side portions, wherein the side portions are exclusively connected to the cross member at opposite ends of the cross member, wherein the connection between the side portions of the back shell and the end portions of the cross member are the only connections between the side portions of the back shell and the back frame, and a cover extending across the opening and connected to the side portions and the top portion of the back shell.

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 chair back assembly includes a back frame having a front surface and a rear surface and including a laterally extending cross member having opposite end portions, a back shell including a front surface, a rear surface positioned in front of the front surface of the back frame, a pair of laterally spaced side portions defining an opening therebetween, and a top portion extending laterally between and connected to the side portions, wherein the side portions are exclusively connected to the cross member at opposite ends of the cross member, wherein the connection between the side portions of the back shell and the end portions of the cross member are the only connections between the side portions of the back shell and the back frame, and a cover extending across the opening and connected to the side portions and the top portion of the back shell.

Abstract: A chair back assembly includes a substantially rigid back frame assembly, a back shell member operably supported by the back frame assembly and including a laterally extending top portion, a laterally extending bottom portion and a pair of longitudinally extending side portion extending between the top portion and the bottom portion and cooperating therewith to define an open space therebetween, wherein the pair of side portions are substantially rigid in a lateral direction, and wherein the back shell member is substantially rigid in a lateral direction and substantially flexibly resilient in a fore-to-aft direction, and a cover having a first surface adapted to support a seated user and a second surface opposite the first surface, wherein the cover is positioned over the back shell member to cover at least a portion of the open space.

Abstract: A chair control assembly includes a base structure having first and second pivot points spaced from one another, a seat support structure coupled to the first pivot point, a back support structure coupled to the second pivot point and adapted to move between first and second positions, wherein the base structure does not move as the back support structure moves between the first and second positions, and a control link pivotably coupled to the seat support structure for rotation about a third pivot point and pivotably coupled to the back support structure for rotation about a fourth pivot point, wherein the third pivot point is rearward of the fourth pivot point when the back support structure is in the upright position, and the third pivot point moves forward relative to the fourth pivot point as the back support structure moves from the upright to reclined positions.

Abstract: A chair control assembly includes a base structure having first and second pivot points spaced from one another, a seat support structure coupled to the first pivot point, a back support structure coupled to the second pivot point and adapted to move between first and second positions, wherein the base structure does not move as the back support structure moves between the first and second positions, and a control link pivotably coupled to the seat support structure for rotation about a third pivot point and pivotably coupled to the back support structure for rotation about a fourth pivot point, wherein the third pivot point is rearward of the fourth pivot point when the back support structure is in the upright position, and the third pivot point moves forward relative to the fourth pivot point as the back support structure moves from the upright to reclined positions.

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 the base structure for rotation about the first pivot point, a back support structure having a forward portion pivotably coupled to the base structure for rotation about the second pivot point, wherein the back support structure is adapted to move between upright and reclined positions, and wherein the seat support structure reclines rearwardly as the back support structure moves from the upright to reclined 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 back assembly includes a substantially rigid back frame assembly, a back shell member operably supported by the back frame assembly and including a laterally extending top portion, a laterally extending bottom portion and a pair of longitudinally extending side portion extending between the top portion and the bottom portion and cooperating therewith to define an open space therebetween, wherein the pair of side portions are substantially rigid in a lateral direction, and wherein the back shell member is substantially rigid in a lateral direction and substantially flexibly resilient in a fore-to-aft direction, and a cover having a first surface adapted to support a seated user and a second surface opposite the first surface, wherein the cover is positioned over the back shell member to cover at least a portion of the open space.

Abstract: A chair assembly includes a base structure defining upper and lower portions, and a support structure, a seat support structure having a forward portion pivotably connected to the upper portion of the base structure for rotation about a first pivot point and a rearward portion, a back support structure having a forward portion pivotably connected to the lower portion of the base structure for rotation about a second pivot point that is located below and rearward of the first pivot point, and an upwardly extending back portion that moves rearwardly and downwardly as the back support structure pivots and the back portion moves, and a control link pivotably coupled to the seat support structure for rotation about a third pivot point and to the back support structure for rotation about a fourth pivot point each located rearward of the first and second pivot points.

Abstract: 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.

Abstract: A chair back assembly includes a back shell member including laterally extending top, bottom and side portions cooperating to define an open space therebetween, where a portion of the back shell member is located in a lumbar region, a cover having a first surface and a second surface opposite the first surface, wherein the cover covers at least a portion of the open space, and a back frame assembly operably supporting the back shell member and movable between upright and reclined positions, wherein the back frame assembly causes the back shell to flex in a fore-to-aft direction as the back frame assembly is moved between the upright and reclined positions independent of an external force being exerted on the back shell member, and where the lumbar portion of the back shell member remains spaced from the back frame as the back frame is moved between the upright and reclined positions.

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: 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.

Abstract: A method of assembling a spring inside of a tube includes providing a coil spring and a tube having a first retaining structure at a first end of the tube. The method includes positioning a rod in the tube. The spring is positioned in the tube, and a second retaining structure is attached to the rod with the spring positioned between the first and second retaining structures. A force is applied to the spring, and the second retaining structure is fixed at a position wherein the spring provides a desired preload.

Abstract: A control assembly for a chair including a base structure including a first pivot point and a second pivot point spaced from the first pivot point, and a seat support structure directly 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 move between a first and second position, a control link having a first end operably coupled to the seat support structure, and a second end operably coupled to the back support structure, and a biasing assembly exerting a biasing torque about the second pivot point that biases the back support structure from the second position toward the first position, wherein the biasing torque is adjustable between first and second magnitudes when the back support structure is in the first 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 the base structure for rotation about the first pivot point, a back support structure having a forward portion pivotably coupled to the base structure for rotation about the second pivot point, wherein the back support structure is adapted to move between upright and reclined positions, and wherein the seat support structure reclines rearwardly as the back support structure moves from the upright to reclined 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.