| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the playing performance and external appearance, to increase the degree of freedom of design of a spring, and to make the device small-sized. SOLUTION: A storage room 43 is formed in a clapper 5 and a rotary buffer device 41 and a compression coil spring 42 are built in the storage room 43. A rotary arm 48 of the rotary buffer device 41 is projected upward from an opening 44 formed on the top surface of the clapper 5. The compression coil spring 42 energizes the rotary arm 48 in the direction to which the keyboard lid 8 is opened and a roller 76 provided a top is pressed against the under surface of the keyboard lid 8. The keyboard lid 8 when closing presses down the rotary arm 48 against the spring force of the compression coil spring 42. At this time, the rotary buffer device 41 damps the keyboard lid 8. Therefore, the keyboard lid 8 is not accelerated by its own weight, but is slowly closed.</p> |
