The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 16, 2011
Filed:
Mar. 13, 2006
Hitoshi Izutani, Shizuoka-ken, JP;
Noboru Yamashita, Shizuoka-ken, JP;
Satoshi Inoue, Shizuoka-ken, JP;
Hitoshi Izutani, Shizuoka-ken, JP;
Noboru Yamashita, Shizuoka-ken, JP;
Satoshi Inoue, Shizuoka-ken, JP;
Yamaha Corporation, Shizuoka-ken, JP;
Abstract
Keys of a piano are depressed against the total weight of associated action units and hammers so that balance weight pieces are embedded in the front portion of each key; since the wood bar of the key is expandable and shrinkable due to the conditions of the environment, the weight pieces are liable to come loose; the balance weight piece is formed with ridges and valleys repeated at least 7 times at fine pitches equal to or less than 2 millimeters, and the maximum diameter of the ridges is slightly longer than an inner diameter of a hole formed in the wood bar; while the balance weight piece is being pressed into the hole, the ridges make the inner surface portion elastically deformed; when the balance weight piece reaches the target position, the inner surface portion penetrates into the valleys so that the balance weight piece is lodged therein.