Abstract: A chair armrest device includes a main frame and an outer sleeve coupled to the main frame. The outer sleeve includes an insertion portion having a plurality of positioning grooves. A cover is mounted on top of the outer sleeve. An inner sleeve includes a shank inserted into the insertion portion of the shank. An actuating rod is pivotably received in the inner sleeve. A positioning peg is provided on the actuating rod for releasably engaging with one of the positioning grooves. A guiding peg is provided on the actuating rod and is received in an inclined guiding groove of a button. A pad is mounted on top of the inner sleeve and is pivotable relative to the main frame. The button can be pressed to pivot the actuating rod to thereby disengage the positioning peg from the positioning groove for adjusting a height of the pad.

Abstract: A chair armrest device includes a main frame and an outer sleeve coupled to the main frame. The outer sleeve includes an insertion portion having a plurality of positioning grooves. A cover is mounted on top of the outer sleeve. An inner sleeve includes a shank inserted into the insertion portion of the shank. An actuating rod is pivotably received in the inner sleeve. A positioning peg is provided on the actuating rod for releasably engaging with one of the positioning grooves. A guiding peg is provided on the actuating rod and is received in an inclined guiding groove of a button. A pad is mounted on top of the inner sleeve and is pivotable relative to the main frame. The button can be pressed to pivot the actuating rod to thereby disengage the positioning peg from the positioning groove for adjusting a height of the pad.

Abstract: A backrest assembly includes a front frame having annular outer and inner peripheries. An annular lip is formed on a rear surface of the front frame and extends along the annular inner periphery of the front frame. A net is mounted to a front surface of the front frame. The front frame is received in an annular groove defined between annular inner and outer walls formed on a front face of a rear frame, with the annular inner and outer peripheries and the annular lip of the front frame located between the annular inner and outer walls of the rear frame, with the front surface of the front frame covering a front opening of the annular groove of the rear frame, with a fastener extending through each of a plurality of engaging holes of the front frame into one of the plurality of engaging holes of the rear frame.

Abstract: A combination includes front and rear frames each having a central hollow portion. The central hollow portion of the front frame includes two lateral sides each having a flexible plate with a plurality of vertically spaced positioning grooves. A guiding groove is defined in each of two lateral sides of the central hollow portion of the rear frame. A waistrest includes a support portion. A lug is formed on each of two sides of the support portion. A protrusion is formed on a rear face of each lug and is received in one of the guiding grooves of the rear frame. A positioning member is formed on the front face of each lug. Each flexible plate abuts the front face of one of the lugs. The positioning member of each lug of the waistrest is engaged in one of the positioning grooves of one of the flexible plates.