| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the distortion of a backpost even during the transportation, etc., of a piano. SOLUTION: The backpost 12 of the grand piano is fitted into a mortise groove 16 formed at an inner rim 11. An angle parts 16a of the mortise groove 16 are formed into a prescribed radius of curvature. The angle parts 12a of the backpost 12 are also finished by a round cutter, so as to have the radius of curvature as the radius of curvature at the angle parts 16a of the mortise groove 16. Then, when the backpost 12 is fitted into the mortise groove 16, the mortise groove 16 and the backpost 12 come into contact with each other with no clearances. Even if a grand piano body 10 is therefore erected by removing legs, when transporting the piano such a situation that the backpost 12 is distorted like heretofore will not occur and the effect of eliminating the possibility that a deviation arises in the tension of the strings acting on the backpost 12 is obtained.</p> |
