Patent ID: 8196948

Claim:
An elevating device for a seat cushion of a bicycle comprising: a cylinder having at least one level which is expandable or contractablele inside a frame tube of a bicycle frame; a stick for operating the cylinder; a driving device for driving the stick; and a seat cushion; and wherein an adjustable rod of the cylinder is connected to a base arranged to a bottom of the seat cushion; the stick is arranged below the base of the seat cushion; the stick is linked to the driving device; while the driving device is driven, a control key on a top of the cylinder will be pressed by the stick so that the cylinder is controllable to expand or contract; the driving device includes a roller and a pulley; an end of the stick is linked to an axle of the roller; a rope fixed to the roller is leaded to a lever arranged to a handle stem or a predetermined position of the bicycle frame through the pulley; by the lever pulling the rope, the roller will rotate and the stick fixed to the roller will press the control key so as to adjust a height of the seat cushion.