US Patent 7086632 Keyboard instrument support with adjustable ability

A keyboard instrument support has a driving device to control upward and downward movement of inner tubes relative to the outer tubes and a ratchet device to retain the elevation of the inner tubes. The ratchet device includes a ratchet alternatively rotated by the driving device and a leverage to abut a ratchet tooth. Thus, after the inner tubes are elevated by the driving device, the abutment of the leverage to the ratchet retains the elevation of the inner tubes.