| 摘要 |
<p>PROBLEM TO BE SOLVED: To expose none of a sound member in the front of a framework and prevent sound characteristics from changing by not providing the framework inside, but cutting plural plate members fitted to nearly the entire surface of the back of the framework and providing plural through hole parts. SOLUTION: The framework which supports the keyboard instrument is formed into a rectangular frame type and not provided inside. Plural sound rods 7 are fitted slantingly to the back of a sound board 6 formed by joining plural thin and long plate members slantingly between the sound board 6 and sound rods 7 as sound members which transmits and spreads the sound of the keyboard instrument. A plate member 11 such as plywood is cut to form a large triangular through hole part 12a and small two triangular through hole parts 12b and 12b. The through hole parts 12b and 12b are formed across the through hole part 12a and the thin and long plate members 11 are left at the borders of the respective through hole parts 12a, 12b, and 12b as struts. Consequently, struts can be reduced without any influence on the sound characteristics.</p> |
