| 摘要 |
PROBLEM TO BE SOLVED: To provide an opening/closing structure of a fallboard which is excellent in terms of appearance as the spacings between the fallboard and bass and treble arms are uniform, is low in a manufacturing cost as the number of parts is small and is good in workability in manufacturing. SOLUTION: A fallboard slide rail 51 is installed freely rotatably within a plane parallel to the arm 7 between the under surface of the fallboard 15 and a slide rail supporting member 22 erected from the arm 7. The front end of the fallboard 15 is fitted with a front guide pin 44 projecting to both right and left sides of the fallboard 15. Further, a front guide groove 27 which engages the guide pin 44 and guides the fallboard 15 is formed on the inner side of the arm 7. |
