# US 9,520,107 B2 · Keyboard musical instrument

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- Number: US 9,520,107 B2
- Document ID: US9520107B2
- Status: Granted
- Kind: B2
- Application number: 14/479,617
- Filed: 2014-09-08
- Published: 2015-03-12
- Granted: 2016-12-13
- Earliest claimed: 2013-09-10
- Assignees: Yamaha Corporation
- Applicants: Yamaha Corporation
- Inventors: Tadaharu Kato; Toshiro Sakai
- Web page: https://patentgrep.com/patent/US9520107B2

## CPC

- G10C 3/02: Cases
- B29C 44/02: for articles of definite length, i.e. discrete articles
- B29K 2055/02: ABS polymers, i.e. acrylonitrile-butadiene-styrene polymers
- B29K 2105/0005: {containing compounding ingredients (releasing, lubricating or separating agents B29C33/56, fibers B29K2105/08, B29K2105/12; fillers B29K2105/16, recycled material B29K2105/26)}
- B29K 2105/04: cellular or porous
- B29L 2009/00: Layered products
- B29L 2031/758: {Musical equipment}
- G10C: PIANOS, HARPSICHORDS, SPINETS OR SIMILAR STRINGED MUSICAL INSTRUMENTS WITH ONE OR MORE KEYBOARDS (automatic musical instruments G10F)
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## 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.

## Claims

### Claim 1

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.

### Claim 2 (depends on 1)

The method of manufacturing a fall board according to claim 1, wherein the base resin is an ABS resin.

### Claim 3 (depends on 1)

The method of manufacturing a fall board according to claim 1, wherein the foaming agent is sodium bicarbonate.

### Claim 4 (depends on 1)

The method of manufacturing a fall board according to claim 1, wherein the resin surface layer is made of an ABS resin.