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:
Jul. 15, 2014
Filed:
Mar. 07, 2011
Shigeru Muramatsu, Mori-machi, JP;
Hisashi Takeyama, Hamamatsu, JP;
Shigeru Muramatsu, Mori-machi, JP;
Hisashi Takeyama, Hamamatsu, JP;
Yamaha Corporation, , JP;
Abstract
A keyboard apparatus capable of enhancing the return capability of hammer assemblies upon key release to improve the capability of repeated key striking and capable of reducing a height size of action units to make the keyboard apparatus compact. The keyboard apparatus includes hammer assemblies each having a butt disposed pivotable about a hammer pivot shaft and a hammer shank extending from the butt. In a non-key-depression state, the hammer shank obliquely extends downward. As viewed from side, a straight line passing though a gravity center position of the hammer assembly and the hammer pivot shaft forms an acute angle less than 45 degrees relative to a horizontal plane in the entirety of a key depression and key release stroke.