US Patent 7229054 Height adjustable pedal ring mechanism for bar stool

This invention relates to a height adjustable pedal-ring mechanism for bar stool. This mechanism comprises a main shaft, a taper sleeve, a cross-shaped support frame with a central tube, a pedal ring, and a base frame. The pedal ring is connected to the cross-shaped support frame. The taper sleeve has an outer spiral line on the upper part of the taper sleeve and an outer gradient slope on the lower part of the taper sleeve. The cross-shaped support frame is equipped with a central tube at the central part of the cross-shaped support frame. The central tube has an inner spiral line matching with the outer spiral line of the taper sleeve and an inner gradient slope matching with the outer gradient slope of the taper sleeve. This mechanism employs the outer gradient slope of the taper sleeve and the inner gradient slope of the central tube to fix the vertical position of the pedal ring.