To realize a noble, useful seat with a simple structure designed to follow a natural movement of a seated person in front-rear and left-right directions and to support appropriately a movement of the person continuously changing its posture while the person balances a load. The seat includes the elastic support layer 3 and upper and lower base units 4 and 5 arranged to sandwich the elastic support layer 3. The upper base unit 4 includes the rolling surface 42e bulging toward the lower base unit 5 thereabove via the elastic support layer 3, is rollable in a 360° direction from the tilt reference position IRP in receiving a load of the seated person, and has a moving distal end side tilting more downward as a distance from the position IRP increases, and is configured to move while compressing the elastic support layer 3 by the rolling surface.

An exemplary seat having seat connection mechanism for attaching the seat to a wheelchair includes a seat frame and a backrest. The backrest is pivotably connected to the seat frame through a pivoting mechanism. The seat further includes a biasing member connected to the backrest at a first connection point and a second connection point near the seat frame. The second connection point and the pivoting mechanism are spaced apart from one another by a distance C. The seat further includes an adjustment mechanism adapted for changing the distance C. The second connection point may be connected to a guide arm, such that the position of the second connection point is adjustable by sliding the second connection point along the guide arm, thus making the distance C adjustable.

An adjustable rotary rocking chair having a chair frame assembly A, an adjustment mechanism B, and a support tube assembly C, wherein the adjustment mechanism B is detachably connected with the chair frame assembly A and is connected with the support tube assembly C in an insertion manner. The adjustable rotary rocking chair can swing and rotate, has higher flexibility and adaptability due to the fact that the height of the rocking chair and the height of the support tubes can be automatically adjusted by users, is portable through a folding design, and can be used indoors and outdoors.

Embodiments provide a seat connecting device with an adjustable backrest, belonging to the technical field of swivel chairs. In the embodiments, the seat connecting device includes a seat back tightness control assembly including a control handle, a universal joint, a transmission rod, a first bevel gear, a second bevel gear, a lifting part, a mounting seat of the lifting part, and a tightness adjust rod. The present disclosure uses the universal joint to replace the original rope for transmission, improving the response timeliness of the force transmission of the product when adjusting the seat back elasticity; and improving the accuracy and controllability of the seat back elasticity adjustment. At the same time, relative to the use of rope adjustment method, the size of the force arm can be also effectively improved, the size of the force transmission of the product during regulation and the demand for the size of the force transmission are improved, the force requirements for the user is reduced, and the possibility of damage to the adjustment mechanism due to excessive input force when the product is adjusted is effectively reduced, thereby increasing the service life of the product.

An ergonomic massage chair is configured with back and bottom structures held up by a pair of legs. The various support bars and structure of the ergonomic massage chair may be comprised of, in typical implementations, metal, but plastic and other suitable structures are also possible. The back structure has perimeter support bars that form the base of the back support, and horizontal support bars extend from a left perimeter support bar to a right perimeter support bar. The bottom structure likewise has a perimeter support bar that forms the structure of the bottom. A horizontal support bar extends from a left perimeter support bar to a right perimeter support bar. Nodes are attached to the ergonomic chair, and stability balls fit inside openings created by the support bars and nodes. A cover having memory foam pillows therein encapsulates the chair to provide users with customized setups that suit them.

To realize a noble, useful seat with a simple structure designed to follow a natural movement of a seated person in front-rear and left-right directions and to support appropriately a movement of the person continuously changing its posture while the person balances a load. The seat includes the elastic support layer 3 and upper and lower base units 4 and 5 arranged to sandwich the elastic support layer 3. The upper base unit 4 includes the rolling surface 42e bulging toward the lower base unit 5 thereabove via the elastic support layer 3, is rollable in a 360° direction from the tilt reference position IRP in receiving a load of the seated person, and has a moving distal end side tilting more downward as a distance from the position IRP increases, and is configured to move while compressing the elastic support layer 3 by the rolling surface.

An air cushion device for a seat includes at least one first air cushion and a second air cushion, first and second air inlets, first and second air ducts, and a device preventing the second air duct from being pinched off by a fixing wire of a seat cover.

A reconfigurable chair includes features that open up new sitting and resting positions for the user. The chair includes rotatable lateral side rests and a tilt adjustable back rest which when reconfigured, provide auxiliary resting platforms to support the body in different sitting and resting positions. The backrest may include a rotatable feature so that the backrest may be moved from an upright position to a flat position adding another level of support. A height adjustment mechanism may adjust the height of the backrest to add to the reconfigurability of the chair. Some embodiments include one or more gas pistons providing user-controlled adjustment of elements into any of an infinite number of user-controlled positions.

An ergonomic massage chair is configured with back and bottom structures held up by a pair of legs. The various support bars and structure of the ergonomic massage chair may be comprised of, in typical implementations, metal, but plastic and other suitable structures are also possible. The back structure has perimeter support bars that form the base of the back support, and horizontal support bars extend from a left perimeter support bar to a right perimeter support bar. The bottom structure likewise has a perimeter support bar that forms the structure of the bottom. A horizontal support bar extends from a left perimeter support bar to a right perimeter support bar. Nodes are attached to the ergonomic chair, and stability balls fit inside openings created by the support bars and nodes. A cover having memory foam pillows therein encapsulates the chair to provide users with customized setups that suit them.

Embodiments provide a seat connecting device with an adjustable backrest, belonging to the technical field of swivel chairs. In the embodiments, the seat connecting device includes a seat back tightness control assembly including a control handle, a universal joint, a transmission rod, a first bevel gear, a second bevel gear, a lifting part, a mounting seat of the lifting part, and a tightness adjust rod.