Back to results
US 9,520,107 B2Granted
Keyboard musical instrument
AssigneeYamaha Corporation
InventorsTadaharu Kato, Toshiro Sakai
Life of this patent
Estimating the term…
Abstract
Provided is a keyboard musical instrument such as an acoustic piano or an electronic piano having an appearance and design similar to an acoustic piano, in which a fall board is made of a resin plate-shaped body, and hollow portions are provided inside the plate-shaped body. In addition, the plate-shaped body includes a plate-shaped resin foamed plate portion, and the hollow portions are made of plural air bubbles contained inside the resin foamed plate portion.
Claims4
A method of manufacturing a fall board, the method comprising:
- mixing a foaming agent, which produces gas when being heated, with a base resin to form a mixed resin material;
- supplying the mixed resin material to a molding die;
- heating the molding die to allow a plurality of air bubbles to be formed inside the mixed resin material and to thereby obtain a resin foamed plate having a plurality of hollow portions therein;
- and
- laminating a resin surface layer on a surface of the resin foamed plate.
2 more elements
Dependencies are inferred from the claim text.