| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the manufacture cost by molding the frame of the musical instrument keyboard device in one body as well by maintaining necessary strength. SOLUTION: The frame 10 has a key assembly part 11 for assembling keys 20 and 30, a top plate 12 which is extended horizontally forward from the key assembly pat 11, and a bottom plate 13 which is extended backward having its front end below the front end parts of the keys 20 and 30. Those key assembly part 11, top plate 13, and bottom plate 13 are connected by a vertical rib plate 15 and molded in one body. The keys 20 and 30 are assembled in a swingable state by the key assembly part 11, a swing lever 40 which engages the keys 20 and 30 to give reaction against keying operation is assembled in a swingable state above the rear end part of the bottom plate 13, and a printed board 54 is also assembled on the bottom plate 13.</p> |
