Keyboard instrument, key base molding method, and key base molding mold

Patent metadata

Field	Value
Publication number	US-12394396-B2
Application number	US-202318133228-A
Country	US
Kind code	B2
Filing date	Apr 11, 2023
Priority date	Apr 28, 2022
Publication date	Aug 19, 2025
Grant date	Aug 19, 2025

Abstract

A keyboard instrument includes a key which includes a weight, and a key base including a top plate and at least one rib configured to fix the weight by holding the weight from below in such a state that the weight is kept in abutment with a lower surface of the top plate.

First claim

What is claimed is:

1. A keyboard instrument comprising:
a key comprising:
a weight; and
a key base comprising a top plate and at least one rib configured to fix the weight by holding the weight from below in such a state that the weight is kept in abutment with a lower surface of the top plate,

wherein the at least one rib is at least one rib provided on a black key, and
wherein the at least one rib provided on the black key is configured to come into contact with a switch configured to detect a key depression when the black key is depressed.

2. The keyboard instrument according to claim 1 , wherein the at least one rib comprises a first rib and a second rib,
wherein the key base further comprises left and right side plates which are connected to and extend downward from the top plate, and
wherein the weight, the first rib, and the second rib are provided between the left and right side plates.

3. The keyboard instrument according to claim 1 , wherein the at least one rib comprises a first rib, and
wherein the first rib is configured to fix the weight at one of a front and a back of the weight in a front-back direction of the key.

4. The keyboard instrument according to claim 3 , wherein the at least one rib further comprises a second rib, and
wherein the second rib is configured to fix the weight at the other of the front and the back of the weight in the front-back direction of the key.

5. The keyboard instrument according to claim 1 , wherein the at least one rib extends along a vertical plane which is parallel to a center line of the weight in a front-back direction of the key.

6. The keyboard instrument according to claim 1 , wherein the key base further comprises an auxiliary rib which extends along an alignment direction of the key and which is configured to fix the weight by holding the weight from below in such a state that the weight is in abutment with the lower surface of the top plate.

7. The keyboard instrument according to claim 1 , wherein the key base further comprises left and right side plates which are connected to and extend downward from the top plate, and
wherein the at least one rib connects to a reinforcement rib which connects the left and right side plates to each other.

8. The keyboard instrument according to claim 1 , wherein the key base further comprises left and right side plates which are connected to and extend downward from the top plate,
wherein the at least one rib provided on the black key comprises a first switch depressing rib connecting to the left and right side plates and a second switch depressing rib configured to fix a back of the weight in a front-back direction of the black key, the first switch depressing rib and the second switch depressing rib being provided in such a manner as to intersect each other at right angles, and
wherein a portion where the first plate-shaped switch depressing rib and the second switch depressing rib intersect each other at right angles is configured to come into contact with the switch when the black key is depressed.

9. A key base molding method comprising:
inserting a weight in a weight inserting portion provided in a core mold of a mold to dispose the weight in place in the weight inserting portion;
clamping the core mold and a cavity mold of the mold together; and
injecting a molten resin into the mold having been clamped to thereby mold a key base comprising a rib which extends in a vertical direction and which fixes the weight.

10. A key base molding mold comprising:
a cavity provided in a cavity mold; and
a core block provided in a core mold,
wherein the core block comprises a weight inserting portion comprising a rib molding portion,
wherein the weight inserting portion is formed into a recess having a shape of a frustum in which a base side having a larger surface area is disposed outwards of the recess, and
wherein the rib forming portion is formed into a groove extending from an outer circumferential surface of the weight inserting portion which has the shape of the frustum to a base side having a smaller surface area.

Assignees

• Casio Computer Co Ltd

Inventors

• Shiraishi Yasushi
• Taniguchi Hirokazu

Classifications

• G10C3/12 Primary

  Keyboards; Keys · CPC title

• G10B3/12

  Keys or keyboards; Manuals · CPC title

• G10C9/00 Primary

  Methods, tools or materials specially adapted for the manufacture or maintenance of musical instruments covered by this subclass · CPC title