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.

An armrest includes a shell convertible between a fixed position and a non-fixed position, a lock unit, and a control unit. The lock unit includes a base seat and two pivot gears, each of which has an arm segment and a gear segment having a plurality of first teeth. The control unit includes a rack having a plurality of second teeth and is operable to move between a locking position and an unlocking position. When the control unit is at the locking position, the second teeth mesh with the first teeth, the pivot gears are locked, and the shell is at the fixed position. When the control unit is at the unlocking position, the rack is away from the pivot gears, the pivot gears are pivotally rotatable, and the shell is at the non-fixed position.

A chair assembly includes a back support arrangement including a back support arrangement, a seat support arrangement and a four-bar arrangement that includes a rearward end and a forward end that is adjustable between a raised and lowered positions, and an arm rest assembly adapted to support the arm of a seated user thereon and supported on the forward end of the four-bar arrangement, wherein the rearward end of the four-bar arrangement is pivotably supported from an arm support structure for pivotable movement about a substantially vertical pivot axis such that the forward end of the four-bar arrangement is moveable between a first position and second position located laterally outward from the first position, and wherein the substantially vertical pivot axis is located forwardly of a rearmost edge of an upwardly-facing surface of the seat support arrangement.

A portable chair may include a first front leg and a second front leg connected by a front sled and a first back leg and a second back leg connected by a back sled. The first front leg and the first back leg may be pivotally connected to a sliding pivot on an armrest, where the sliding pivot moves relative to the armrest to adjust the chair from an upright position to a reclined position. The seat assembly may include a fabric member that is attached secured to a seat frame by a plurality of fabric retention members. In some examples, the portable chair may include a fabric member is releasably connected to the seat frame and back frame and also extends from a forward rail of the seat frame to a top rail of the back frame.

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.

An adjustable armrest assembly for a stool or chair comprises an armrest base, an armrest support member and an adjustment assembly. The armrest base is connectible to the stool or chair and has a first opening. The armrest support member has a first end with a second opening. The first end is positionable with the second opening aligned with the first opening. The armrest support member has a second end opposite the first end and extending distally to support an armrest. An adjustment assembly is positionable to extend through the second opening and the first opening to define a pivot axis and an adjustable pivot connection between the support member and the base. The assembly is movable within at least one of the first opening and the second opening to laterally reposition the pivot axis. A variable friction member applies a selected degree of resistance to the adjustable pivot connection.

An armrest assembly includes a mounting plate disposed on a support column and having an elongated moving slot for a first pivot shaft to movably extend therethrough, an armrest plate having a sliding slot elongated transverse to the moving slot such that the first and second pivot shafts extend through and are slidable along the sliding slot to allow the armrest plate to be horizontally movable and turnable relative to the mounting plate, and a retaining unit disposed to produce a magnetically attractive force that generates resistance against a relative movement of the armrest plate to the mounting plate.

An armrest adjuster includes a slider, a fixing member moveably mounted into a concave space of the slider, and a button is revealed. Two pins set on a bottom surface of the fixing member are moveably mounted in two long grooves on a bottom surface of the slider respectively. Each pin is set with a through hole for being fastened on a top of a vertical support of an armrest. The button exposed is clipped between the slider and the fixing member. The button is disposed with a rack while another rack corresponding to the rack of the button is arranged at the fixing member. The rack of the button is separated from the rack of the fixing member when the button is pressed. Thus the slider is moved horizontally relative to the fixing member. The design is beneficial to the assembly process, modularization and mass production.

An armrest includes a shell convertible between a fixed position and a non-fixed position, a lock unit, and a control unit. The lock unit includes a base seat and two pivot gears, each of which has an arm segment and a gear segment having a plurality of first teeth. The control unit includes a rack having a plurality of second teeth and is operable to move between a locking position and an unlocking position. When the control unit is at the locking position, the second teeth mesh with the first teeth, the pivot gears are locked, and the shell is at the fixed position. When the control unit is at the unlocking position, the rack is away from the pivot gears, the pivot gears are pivotally rotatable, and the shell is at the non-fixed position.

An armrest assembly includes a mounting plate disposed on a support column and having an elongated moving slot for a first pivot shaft to movably extend therethrough, an armrest plate having a sliding slot elongated transverse to the moving slot such that the first and second pivot shafts extend through and are slidable along the sliding slot to allow the armrest plate to be horizontally movable and turnable relative to the mounting plate, and a retaining unit disposed to produce a magnetically attractive force that generates resistance against a relative movement of the armrest plate to the mounting plate.