A chair comprising a base structure comprising a support, a seat connected to the support via a synchronization mechanism and movable with respect to the base structure between a lowered position and a raised position, and a backrest connected to the synchronization mechanism and movable between an upright position, corresponding to the lowered position of the seat, and a backward-inclined position corresponding to the raised position of the seat, wherein the synchronization mechanism comprises two loop-shaped elastic elements spaced apart in a transverse direction and each comprising a lower portion fixed to a rigid support, an upper portion fixed to the seat, a front elastic portion and an essentially C-shaped rear elastic portion that connect the upper portion to the lower portion, wherein the backrest is fixed to the rear elastic portions of the loop-shaped elastic elements.

An adjustable chair has a seat and a splat. The seat has a lower base, an upper base, a tilt adjusting device, a lower rotating shaft, and an upper rotating shaft. The lower base has an assembling space. The upper base is movably deposited on the lower base. The tilt adjusting device is deposited in the assembling space. The lower rotating shaft is rotatably deposited in the lower base and connected to the tilt adjusting device. The upper rotating shaft is deposited in the upper base. The splat is tiltably connected to the seat and has a backrest unit and two connecting legs. The backrest unit is deposited at a rear side of the seat. The connecting legs are connected to the backrest unit, are connected to the lower rotating shaft, and are pivotally connected to the upper rotating shaft.

The invention includes a frame, a back board and an adjustment set. The frame has a central trench and an adjustment board with limiting slots and two sliding slots. The back board is connected to the frame and has an opening. The adjustment set is connected between the frame and the back board and includes: a sliding seat having an engagement block received in the opening, and the engagement block having a recess with a through hole; a limiting body received in the recess, having a central bar in the through hole and an extending portion with a limiting bar in the limiting slots, and a C-shaped trench around the central bar; a torsion spring received in the C-shaped trench, two ends thereof protruding from the C-shaped trench and stopped by the recess; and two sliders received in the sliding slots. The sliders and the sliding seat are fixed to the back board.

A furniture system includes a base, a first linkage and a second linkage. The base is configured to be disposed on a flat surface and to be connected to an article of furniture. The first linkage is connected to the base and configured to be connected to the article of furniture. The first linkage is configured to be actuated to cause the article of furniture to translate relative to the base. The second linkage is connected to the first linkage. The second linkage is biased into a locked state in which the second linkage prevents movement of the first linkage. The second linkage is configured to be actuated by an applied force into an unlocked state in which the second linkage allows movement of the first linkage (and the article of furniture to which the first linkage is configured to be connected).

The invention includes a frame, a back board and an adjustment set. The frame has a central trench and an adjustment board with limiting slots and two sliding slots. The back board is connected to the frame and has an opening. The adjustment set is connected between the frame and the back board and includes: a sliding seat having an engagement block received in the opening, and the engagement block having a recess with a through hole; a limiting body received in the recess, having a central bar in the through hole and an extending portion with a limiting bar in the limiting slots, and a C-shaped trench around the central bar; a torsion spring received in the C-shaped trench, two ends thereof protruding from the C-shaped trench and stopped by the recess; and two sliders received in the sliding slots. The sliders and the sliding seat are fixed to the back board.

A positioner of a chair adjusting device is disclosed. The positioner is formed by stacking a plurality of positioning plates together. Each of the positioning plates is formed with a positioning section, a combination section, and a penetration section. The combination section is formed of a recessed cavity recessed from one surface and a projecting peg projecting from an opposite surface, and an outside diameter of the projecting peg corresponds to an inside diameter of the recessed cavity, so that for two of the positioning plates that are stacked together to be respectively on an upper side and a lower side, the projecting peg of the positioning plate on the upper side is receivable into and fit in the recessed cavity of the positioning plate on the lower side to have the two positioning plates that are stacked together on the upper and lower sides combined together through tight fitting.

A seat-backrest linkage device includes a base, a bracket plate, a swing bracket and a connecting member. The connecting member includes a crank and a connecting plate connected as a whole. The swing bracket is provided between the base and the bracket plate. Two ends of the crank are respectively hinged to the bracket plate and the swing bracket. An slide groove guide mechanism is provided between the bracket plate and the swing bracket. The swing bracket and the base are hinged in middles, such that the swing bracket, the connecting member, and the bracket plate are capable of together tilting and swinging left and right relative to the base. The support plate seat can be raised and lowered relative to the base, and the swing bracket hinged to the base is arranged between the base and the support plate seat.

A chair of an aspect of the present disclosure includes: a support base; and a chair body including a seat frame that extends in the forward-rearward direction and forms at least part of a seat, and a back frame that is provided in the rear end of the seat frame to be pivotable around an axis O1 extending in the left-right direction, extends upward from the seat frame, and forms at least part of a backrest. The support base includes a slider that supports, in front of the axis O1, the seat frame movably in the forward-rearward direction, and a backrest-supporting shaft that supports, below the axis O1, the back frame pivotably around an axis O2 extending in the left-right direction.

The present invention provides an adaptive swing component for chair back reclining, a chair back reclining locking mechanism and a chassis, wherein the adaptive swing component comprises a main shaft and a motion assembly, wherein the motion assembly comprises a first moving member, a track seat and a second moving member which rotate synchronously around the main shaft; the chair back reclining locking mechanism comprises the above-mentioned adaptive swing component, which has an adjustment state and a locking state, wherein in the adjustment state, the first moving member is disengaged from the second moving member, the chair back can rotate and drive the first moving member to move in the adjustment direction and rotate relative to the main shaft; and the locking mechanism is applied to the chassis; in the locking state, the first moving member is combined and locked with the second moving member to lock the current reclining angle of the chair back; the entire motion assembly is interlocked and rotates together relative to the main shaft to realize adaptive swinging and prevent motion interference and jamming; the structural locking can solve the problems of friction plate wear and failure, noise, etc., and the operation is easier, the structure is simple, and the cost is maintained at a low level.