Apparatus for opening and closing top board of grand piano
Manabu Arimori · The Journal of the Acoustical Society of America · 2003
In an apparatus for opening an closing a top board of a grand piano, the top board is hingedly supported along one side thereof on an outer rim of the grand piano. The apparatus has a gear-type of jack made up of a jack main body fixed to a wooden fame of the grand piano, and a rod which is movable in a longitudinal direction through the jack main body and which supports the top board in a manner to open and close said top board.