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:
Dec. 17, 1991
Filed:
Jul. 24, 1990
Katsuhiko Imagawa, Shizuoka, JP;
Yamaha Corporation, Hamamatsu, JP;
Abstract
A sound board incorporated in a musical instrument such as, for example, a piano or a string instrument comprises a wooden plate member containing wood fibers substantially oriented to a first direction, and a plurality of thread members fixed to at least one major surface of the wooden plate member at spacings and extending in directions substantially parallel to the first direction, in which the wooden plate member has a first modulus of longitudinal elasticity to a force exerted thereto in a direction substantially parallel to the first direction and in which each of the thread members has a second modulus of longitudinal elasticity larger than the first modulus of longitudinal elasticity so that the sound board is reinforced against a force in the direction substantially parallel to the first direction only, thereby allowing the sound board to produce a soft deep sound.