Keyboard instrument

Patent metadata

Field	Value
Publication number	US-12315474-B2
Application number	US-202318203706-A
Country	US
Kind code	B2
Filing date	May 31, 2023
Priority date	Dec 3, 2020
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

A keyboard instrument has a first member having a first fixation fulcrum, a first link rotatably fixed to the first fixation fulcrum at one end side thereof, a second member having a second fixation fulcrum provided further forwards and downwards than the first fixation fulcrum, a second link rotatably fixed to the second fixation fulcrum at one end side thereof, and a coupling link fixed to a key so as to couple the other end side of the first link and the other end side of the second link together.

First claim

What is claimed is:

1. A keyboard instrument comprising:
a first member comprising a first fixation fulcrum;
a first link pivotally supported on the first fixation fulcrum at a first end side of the first link;
a second member comprising a second fixation fulcrum provided further forwards and downwards than the first fixation fulcrum with respect to a front-back direction and an upper-lower direction of the keyboard instrument;
a second link pivotally supported on the second fixation fulcrum at a first end side of the second link; and
a coupling link configured to fix a second end side of the first link which is configured to rotate about the first fixation fulcrum in response to a key operation and a second end side of the second link which is configured to rotate about the second fixation fulcrum in response to the key operation so that a distance stays unchanged, the distance being a distance defined between the second end side of the first link and the second end side of the second link.

2. The keyboard instrument according to claim 1 ,
wherein a coupling of the coupling link with the first link is disposed further upwards and forwards than a coupling of the coupling link with the second link.

3. The keyboard instrument according to claim 1 , further comprising a hammer, the hammer comprising a weight at a first end side thereof and being coupled to a key at a second end side thereof.

4. The keyboard instrument according to claim 3 ,
wherein the second member comprises a fulcrum configured to pivotally support the hammer in such that the hammer is rotatable about the fulcrum.

5. The keyboard instrument according to claim 1 ,
further comprising a key guide configured to guide a movement of the key in response to the key operation, the key guide being provided on each of a front side and a back side of the key.

6. The keyboard instrument according to claim 1 ,
wherein a length of the first link is longer than a length of the second link, and
wherein a sum of the length of the first link and the length of the second link is longer than a length from the first fixation fulcrum to the second fixation fulcrum.

7. The keyboard instrument according to claim 1 , further comprising:
a cam; and
a cam follower configured to engage with the cam,
wherein the cam and the cam follower are provided further backwards than the coupling link.

8. The keyboard instrument according to claim 1 ,
wherein a first rotation angle at which the first link rotates about the first fixation fulcrum in response to the key operation is larger than a second rotation angle at which the key rotates about an imaginary fulcrum in the upper-lower direction in response to the key operation.

Assignees

• Casio Computer Co Ltd

Inventors

• Ichikawa Kenzo
• Mizushina Takahiro
• Nimura Wataru

Classifications

• G10H1/344

  Structural association with individual keys (electrically operated wind-actuated organs G10B3/22) · CPC title

• G10H1/34

  Switch arrangements, e.g. keyboards or mechanical switches specially adapted for electrophonic musical instruments · CPC title

• G10B3/12

  Keys or keyboards; Manuals · CPC title

• G10B3/10

  Actions, e.g. key actions, couplers or stops · CPC title

• G10C3/12 Primary

  Keyboards; Keys · CPC title