| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable a fallboard to stably be opened and closed and make is possible to close it slowly, and attach and detach the fallboard easily without using any tool by providing a link mechanism which has one end part connected to the fallboard and a buffer unit which brakes the fallboard when the fallboard rotates in the closing direction. SOLUTION: To When the fallboard 1 is raised from its closure positiong, the fallboard 1 rotates counterclockwise, i.e., backward and the shaft part 14 of the buffer unit 11 fitted to fallboard back section 3 which is constituted attachably to and detachably from a piano main body is drawn by the link mechanism 12 to rotate clockwise. Then the keyboard lid 1, link mechanism 12, and the shaft part 14 of the buffer unit 11 reach opening positions. When the fallboard 1 is fallen to the front side form the opening position, the fallboard 1 rotates clockwise. At this time, the braking force of the buffer unit 11 operates on the fallboard 1 through the link mechanism 12 and the rotation of the fallboard 1 is reduced in speed with the braking force and buffered. Further, the braking force of the buffer unit 11 gradually increases as the fallboard 1 approaches the closure position.</p> |
