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:
Jan. 02, 1990
Filed:
Oct. 11, 1988
Masanori Katsuta, Iwata, JP;
Tsutomu Yamaguchi, Iwata, JP;
Yutaka Tamai, Hamamatsu, JP;
Norizo Kamimura, Hamamatsu, JP;
Kabushiki Kaisha Kawai Gakki Seisakusho, Shizuoka, JP;
Abstract
An improved key device for an electronic keyboard musical instrument of the type having a fulcrum and a chassis each mounted on a support, and having a key pivotably mounted on the fulcrum, is further provided with a rotor rotatably coupled to the chassis. A first end of the rotor is in contact with an after-fulcrum rear end of the key. A key-returning spring is arranged to couple the rotor and the chassis. A rotation shaft member is fastened to the chassis, the rotor having a recessed portion for receiving the rotation shaft member whereby the rotor is rotatable relative to the rotation shaft member. A heavy mass portion is fastened to a second end of the rotor, the first and second ends of the rotor being on opposite sides of a rotational center of the rotation shaft member. A stopper is mounted on the chassis for suppressing vibrations of the rotor generated when the key is depressed.