A lifting device for an armrest contains: a first fitting tube, a second fitting tube, and a holder. The first fitting tube includes a connector, a hollow part, a first channel, and a second channel. The first channel has a vertical section and a hollow section, the second channel has an operation area, multiple positioning teeth, multiple limitation areas, plural protrusions, and multiple defining recesses. The second fitting tube is hollow and includes a lateral part and a longitudinal part fitted on an outer wall of the lateral part of the first fitting tube, and the longitudinal part has a projection arranged on an inner wall of the longitudinal part and housed in one of the multiple defining recesses. The holder is mounted on a top of the lateral part of the second fitting tube.

An adjustable armrest assembly including a base configured to be mounted on a side of seat, an armrest, and an adjustment assembly configured to adjustably couple the armrest to the base. The adjustment assembly includes first and second rows of grooves, an adjustment slot located between the first and second rows of grooves, a clip stopper configured to selectively engage the first and second rows of grooves, and a threaded stud coupling the clip stopper to the armrest. When the armrest is rotated in a first direction, teeth of the clip stopper disengage a first pair of grooves and permit the armrest to slide relative to the adjustment slot to adjust the armrest into a desired position. When the armrest is rotated in a second direction, the teeth of the clip stopper engage a second pair of grooves to set the armrest in the desired position.

A chair back assembly includes a frame assembly including a pair of slots extending through the frame assembly, a first location positioned between the pair of slots, and a pair of second locations located outward of an outer periphery of the frame assembly, and a vertically adjustable lumbar assembly configured to support a lumbar area of a seated user and including a central portion and a pair of end portions slidably engaging the central portion, the central portion located in the first location and the end portions located in the second locations, wherein the pair of end portion are slidably moveable within the slots between a first position and a second position that is different than the first position.

A chair equipped with shoulder supporter is provided. The chair equipped with shoulder supporter can obtain an effect of attitude remedy by reducing the pressure applied to the spine and by inducing an upright attitude of erecting the waist vertically through a shoulder supporter which is connected to a hip supporter through a base. The shoulder supporter comprises an armpit supporter provided above a vertical supporter. The chair equipped with shoulder supporter can maximize convenience and enable the multi-purpose use by selecting the use and non-use of the arm supporter or the shoulder supporter with the direction change through up-down or forward-rearward direction rotation of the arm supporter or with the folding of the armpit supporter through a rotation shaft.

A chair component assembly includes a support component adapted to support a portion of a seated user and including a shell member having an outer peripheral edge, the support component further including at least one coupler having an interior and an opening facing the outer peripheral edge of the shell member, and at least one tab member located substantially proximate the opening of the at least one coupler, and an upholstery cover assembly wrapped about at least a portion of the support component and including an edge that is retained within the interior of the at least one cupler by the at least one tab member.

A lifting device for an armrest contains: a first fitting tube, a second fitting tube, and a holder. The first fitting tube includes a connector, a hollow part, a first channel, and a second channel. The first channel has a vertical section and a hollow section, the second channel has an operation area, multiple positioning teeth, multiple limitation areas, plural protrusions, and multiple defining recesses. The second fitting tube is hollow and includes a lateral part and a longitudinal part fitted on an outer wall of the lateral part of the first fitting tube, and the longitudinal part has a projection arranged on an inner wall of the longitudinal part and housed in one of the multiple defining recesses. The holder is mounted on a top of the lateral part of the second fitting tube.

A seat armrest is provided. The seat armrest includes a support unit, having a fixed seat and a support rod extending upward from the fixed seat; wherein the support rod has an accommodation space, and the support pole is provided with a positioning slot section composed of a vertical displacement slot and a plurality of horizontal displacement slots communicated with each other; a casing unit, sleeved around the support rod and having an installation groove communicated with the accommodation space; and an adjusting rod, having a positioning protrusion and being pivot disposed on the installation groove of the casing unit.

A height adjustable armrest assembly includes: a fixing bracket portion having an inner space; and a lifting portion provided on top of the fixing bracket portion so as to be movable in the vertical direction. In the lifting portion, a part of a rotation lock portion that is engaged with or disengaged from the fixing bracket portion is formed to rotate toward a front side of the inner space of the fixing bracket portion, thus providing the advantage of greatly improving ease of use for a user.

An armrest assembly includes: a fixation bracket part which is fixed to both of left and right ends of a seat plate part and has an inner space having an open upper side; a lifting part provided at the upper part of the fixation bracket part to be movable in an upward/downward direction; a tilting arm pad part provided at the upper end of the lifting part to be tiltable and slidable in a forward/backward direction; and a safety cover part which inter-operates when the tilting arm pad part is tilted and does not inter-operate when the tilting arm pad is slid, and covers a part between the lifting part and the tilting arm pad part. The tilting arm pad part has a sliding guide slot formed therein to enable a sliding movement thereof in the forward/backward direction with respect to the safety cover part.

An adjustable armrest assembly including a base configured to be mounted on a side of seat, an armrest, and an adjustment assembly configured to adjustably couple the armrest to the base. The adjustment assembly includes first and second rows of grooves, an adjustment slot located between the first and second rows of grooves, a clip stopper configured to selectively engage the first and second rows of grooves, and a threaded stud coupling the clip stopper to the armrest. When the armrest is rotated in a first direction, teeth of the clip stopper disengage a first pair of grooves and permit the armrest to slide relative to the adjustment slot to adjust the armrest into a desired position. When the armrest is rotated in a second direction, the teeth of the clip stopper engage a second pair of grooves to set the armrest in the desired position.