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 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 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. One or more biasing structures may be provided to urge the seat into forward-and-back and side-to-side neutral positions. If desired, the location of this forward-and-back neutral position can be statically adjusted by a user, and at least one of the biasing structures can hold this forward-and-back neutral position at a desired tension level thereby allowing a user to select the amount of force required to move the seat out of this defined forward-and-back neutral position. Moreover, an adjustment structure may be provided that allows for static adjustment of the seatback's position on the spine.

A chair includes a back member and arm brackets. The back member is tapered toward an end that is adjacent to a seat. The arm brackets are attached under a bottom portion of the seat. Each arm bracket is adjustable to provide a seat clearance area for the seat when one or more of the arm brackets are adjusted up to approximately 90 degrees from an original upright position.

A chair that can transition from an upright position to a reclined position includes a base to rest on a floor, a post upstanding from the base, a chassis affixed to a top of the post and having left and right extensions, armrests extending upward from the left and right extensions. A seat is made up of a seat pan and a seat upper support frame, which are positioned under and above the chassis respectively and has a hole through which the post extends. A backrest has a lower end pivotally joined to the seat and a pivotal connection to each of the armrests, so rearward pressure on an upper area of the backrest causes pivoting of the backrest at the armrests and at the seat, pushing the seat forward to a reclined position in a synchronous motion.

An article of furniture has retractable and extendable wheels secured beneath each leg. The mechanism for retraction and extension is accomplished by an activation means in mechanical communication with each wheel.

A spring member is disposed so that a biasing direction is in a forward/rearward direction, and includes a front side engagement portion disposed on a front portion of the spring and a rear side engagement portion disposed on a rear portion of the spring, a seat includes a front side spring receiving portion engaged with a front side engagement portion, a backrest or a support structure includes a rear side spring receiving portion engaged with the rear side engagement portion and an adjustment portion configured to adjust a position of the rear side engagement portion in the upward/downward direction together with the rear side spring receiving portion, and an upper limit position of the rear side engagement portion of the spring member adjusted by the adjustment portion is located above an pivot axis at which the backrest is rotatably supported by the support structure.

A piece of furniture comprises a seat, a backrest and a base. At least the seat and the base are movably coupled for reversible relative adjustment in a direction from a first configuration for sitting upright to a second configuration for sitting reclined. One or more support surfaces and a lever are operably coupled to support the seat on the base. The lever rotates about an axis transverse to the seating direction and moves being coupled with the one or more support surfaces at a first support portion defining first lever arm about the axis and a second, different, support portion defining a second, different, lever arm about the axis. The one or more support surfaces define a curved, noncircular path about the axis, such that relative displacement of the support surface and the axis in the seating direction is associated with rotation of the lever about the axis.

An exercise chair includes a seat assembly, a backrest, a movable supporting member, a position-limiting device, and a resilient position-restoring element. The backrest is pivotally connected to a pivotal connection portion of the seat assembly. The movable supporting member includes a roller for contact with the ground and is pivotally connected to the backside of the backrest. When the tilted state of the backrest is changed, the movable supporting member changes the position at which the ground is in contact with the roller, lest the exercise chair tip over backward. The position-limiting device is connected between the pivotal connection portion and the movable supporting member to adjust and limit the aforesaid contact position. Should the position-limiting device fail, a second position-limiting device provided on the backrest can prevent the exercise chair from falling backward. The resilient position-restoring element helps restore the exercise chair to its most compact configuration.

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.