A seating arrangement includes a seat assembly slidably movable between a forward most position and a rearward most position and that includes a seat support structure configured to support a seated user thereon, and at least one elongated slide bearing attached to the seat support structure and including a bearing surface and at least one stop member, wherein the bearing surface and the at least one stop member are a single, integral piece. The seating arrangement further includes at least one slide support member that slidably supports the slide bearing thereon between the forward most position and the rearward most position, wherein the at least one stop member is configured to prevent the seat assembly from being moved beyond at least one of the forward most position and the rearward most position.

A multifunctional swivel chair tray includes a main body. The main body is connected with a warping plate through a second rotating shaft. An ascending and descending block penetrates through the second rotating shaft. The ascending and descending block is connected with an ascending and descending driving mechanism. A first adjusting rod penetrates through one side of the main body. The first adjusting rod is connected with a multi-spring grouping adjusting mechanism. A second adjusting rod is arranged on another side of the main body. The second adjusting rod is connected with a gear adjusting mechanism. The warping plate is connected with a base plate through a third rotating shaft. A slide plate is slidably connected onto the base plate. A slide plate locking mechanism is arranged between the base plate and the slide plate.

A lower chair for supporting an upper chair on which a user sits. The lower chair including a base, a swivel mechanism supported by the base and defining a vertical swivel axis, and a four-bar linkage mounted to the swivel mechanism for rotation about the swivel axis. The four-bar linkage includes a coupler link that moves about a coupler curve. The lower chair also includes a column having a lower end affixed to the coupler link for movement of the lower end along the coupler curve. The column defines a column axis and is adapted to support the upper chair.

A chair includes a lower chair and an upper chair. The lower chair includes a tilt-swivel mechanism defining a vertical swivel axis, a yoke, and a column extending between the tilt-swivel mechanism and the yoke. The upper chair is pivotably mounted to the yoke about a horizontal upper chair pivot axis. The upper chair includes a seat adapted to cradle the ischial tuberosities of a user.

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.

A seating arrangement includes a rigid back frame, a flexible back shell coupled to the back frame and including a pair of vertical side portions and at least two strap portions extending laterally between the side portions and including a forwardly-facing surface configured to support a back of a seated user, the at least two strap portions including a lowermost strap portion, the lowermost strap portion configured to deflect a first distance when a rearwardly-directed force is exerted on the lowermost strap portion by a seated user, and a lumbar assembly supported from the back frame and configured to support the lumbar region of a back of a seated user, the lumbar assembly configured to deflect a second distance when the rearwardly-directed force is exerted on the lumbar assembly by a seated user, wherein the first distance and the second distance are substantially similar.

A seating arrangement includes a base, a seat assembly operably coupled to the base, and a back assembly that includes a substantially rigid back frame including a pair of side portions spaced from one another and extending upward from the base, and a substantially flexible back shell including a front surface and a rear surface opposite the front surface, a plurality of laterally-extending slots that extend between the front surface and the rear surface and that cooperate to define a plurality of laterally-extending ribs therebetween, where a pair of laterally-extending ribs of the plurality of laterally-extending ribs are connected to one another via a vertically-extending rib located at a substantial midpoint across a width of the back shell, and wherein the back shell is coupled to each of the side portions of the back frame at locations above the plurality of laterally-extending slots.

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.

A chair assembly includes a four-bar arrangement that includes a lower end and an upper end where the upper end is adjustable between a raised position and a lowered position, and an arm rest assembly adapted to support the arm of a seated user thereon and supported on an upper end of the four-bar arrangement, wherein the lower end of the four-bar arrangement is pivotably supported from an arm support structure for pivotable movement about an arm pivot axis, such that the upper end of the four-bar arrangement is movable between a first position and second position located laterally outward from the first position, and wherein the arm pivot axis is angularly offset from a vertical axis.

A seating arrangement includes a seat assembly, a control assembly, a back assembly, and a quick-connection arrangement to connect the back assembly to the control assembly, where the back assembly includes first and second reliefs and the control assembly includes first and second shafts received within the first and second reliefs respectively, and a locking arrangement that includes a primary locking member pivotable between a locked position, where the primary locking member abuts the second shaft arrangement, thereby preventing the second shaft arrangement from being removed from within the second relief, and an unlocked position, where the second shaft arrangement may be removed from within the second relief, thereby allowing the back assembly to be uncoupled from the control assembly.