Patent ID: 7533857

Claim:
A height-adjustable apparatus, comprising: a chassis having a positioning unit and an opening; an actuation unit, movably disposed on the chassis, having a first hole and a first engagement part, the first hole accommodating the positioning unit; an adjustment unit, passing through the opening and being movably disposed on the chassis, the adjustment unit having a plurality of second engagement part; an elastic unit disposed in the first hole and between the positioning unit and the actuation unit; and a washer, disposed on one end of the positioning unit, and the actuation unit being confined between the washer and the chassis, wherein, when the actuation unit is actuated, the first engagement part disengages with the second engagement part to allow movement of adjustment unit, and when the actuation unit is non-actuated, the elastic unit forces the first engagement part to engage with a selected second engagement part to lock the adjustment unit.