Keyboard device for keyboard instrument

• US 7,514,613 B2
• Filed: 07/21/2005
• Issued: 04/07/2009
• Est. Priority Date: 07/28/2004
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Kawai Gakki Seisakusho
• Original Assignee: Kabushiki Kaisha Kawai Gakki Seisakusho
• Inventors: Yamaguchi, Tsutomu
• Primary Examiner(s): Benson; Walter
• Assistant Examiner(s): Qin; Jianchun
• Application Number:
  US11/185,857
• Publication Number:
  US 20060021490A1
• Time in Patent Office: 1,356 Days
• Field of Search: 842/36, 844/34, 844/33
• US Class Current: 84/236
• CPC Class Codes: G10C 3/12 Keyboards; Keys

Abstract

A keyboard device for a keyboard instrument, which can be manufactured by a simplified manufacturing process and at reduced manufacturing costs, is disclosed. A keyframe is formed by a molded piece of a synthetic resin. A plurality of front rail pins and a plurality of balance rail pins are arranged in a juxtaposed manner in a left-right direction at a front part and a central part of the keyframe in a front-rear direction. A plurality of keys are made of wood and each have a balance rail pin hole formed in a central portion thereof in the front-rear direction. The keys are swingably supported on the keyframe in a state where the balance rail pins are each engaged with the balance rail pin hole associated therewith and at the same time the keys are prevented from being swung in the left-right direction by the front rail pins associated therewith.

Claims

1. A keyboard device for a keyboard instrument, comprising:

a keyframe formed by a molded piece of a synthetic resin;

said keyframe formed as a single molded member, wherein the single molded member includes a flat plate-like planar keyframe body, a keyframe center upwardly projecting from a central part of said keyframe body in a front-rear direction and extending in a left-right direction, and a keyframe front on a front part of said keyframe body and extending in the left-right direction, wherein said keyframe body, said keyframe center, and said keyframe front are co-planar;

a plurality of front rail pins arranged on said keyframe front in a juxtaposed manner in the left-right direction;

a plurality of balance rail pins arranged on said keyframe center in a juxtaposed manner in the left-right direction;

a plurality of keys made of wood and each having a balance rail pin hole formed in a central portion thereof in the front-rear direction; and

a first reinforcing member made of metal and provided in a vicinity of the balance rail pins for reinforcement of rigidity of the keyframe,

wherein said keys are swingably supported on said keyframe center in a state where said balance rail pins are each engaged with the balance rail pin hole associated therewith and at the same time said keys are prevented from being swung in the left-right direction by said front rail pins associated therewith.

2. A keyboard device as claimed in claim 1, further comprising a second reinforcing member provided in a vicinity of said front rail pins of said keyframe.

3. A keyboard device as claimed in claim 2, wherein said first reinforcing member and said second reinforcing member respectively extend continuously in the left-right direction.

4. A keyboard device as claimed in claim 1, wherein said balance rail pins are press-fitted in a plurality of balance rail pin recesses formed in said keyframe center, respectively, and thereby mounted on said keyframe center.

5. A keyboard device as claimed in claim 4, wherein said front rail pins are press-fitted in a plurality of front rail pin recesses formed in said keyframe front, respectively, and thereby mounted on said keyframe front.

6. A keyboard device as claimed in claim 1, wherein said keyframe further comprises a hammer supporting part, and

the keyboard device further comprising:

a plurality of hammers that are provided for said keys, respectively, and pivotally supported on said hammer supporting part, each for pivotal motion in accordance with depression of an associated one of said keys.

7. A keyboard device as claimed in claim 1, wherein said keyframe further comprises a back rail-mounting part,

the keyboard device further comprising a back rail that is mounted on said back rail-mounting part, for having said keys brought into contact therewith to thereby define a key release position of said keys, and

wherein said back rail-mounting part is formed with at least one of a recess and a protrusion, for positioning said back rail in a state fixedly engaged at a predetermined location of said keyframe.

8. A keyboard device as claimed in claim 1, wherein said keyframe further comprises a key switch-mounting part,

the keyboard device further comprising a key switch mounted on said key switch-mounting part, for detecting key depression information on each key in accordance with depression thereof, and

wherein said key switch-mounting part is formed with at least one of a recess and a protrusion for positioning said key switch in a state fixedly engaged at a predetermined location of said keyframe.

9. A keyboard device as claimed in claim 1, wherein said keyframe comprises a plurality of keyframes arranged side by side in the left-right direction,

the keyboard device further comprising a connecting member connecting said keyframes to each other.

10. A keyboard device comprising:

a keybed having shape retention;

a keyframe front formed by a molded piece of a synthetic resin wherein the keyframe front molded piece is mounted on an upper surface of said keybed and extends from the upper surface of said keybed without a keyframe body of a keyframe and without a chassis connecting the keyframe front to the keybed, said keyframe front extending in a left-right direction;

a keyframe center formed by a molded piece of a synthetic resin wherein the keyframe center molded piece is mounted on the upper surface of said keybed and extends from the upper surface of said keybed without a keyframe body of a keyframe and without a chassis connecting the keyframe center to the keybed, said keyframe center extending in a left-right direction;

a plurality of front rail pins provided on said keyframe front in a juxtaposed manner in a left-right direction;

a plurality of balance rail pins provided on said keyframe center in a juxtaposed manner in the left-right direction; and

a plurality of keys made of wood and each having a balance rail pin hole formed in a central portion thereof in the front-rear direction,

wherein said keys are swingably supported on said keyframe center in a state where said balance rail pins are each engaged with the balance rail pin hole associated therewith and at the same time said keys are prevented from being swung in the left-right direction by said front rail pins associated therewith.

11. A keyboard device as claimed in claim 10, wherein the keyframe front is a flat, elongated member that is in direct engagement with the keybed along an entire length of the flat, elongated member and wherein the plurality of front rail pins are disposed in the flat, elongated member.

12. A keyboard device as claimed in claim 10, wherein a lower surface of the keyframe center is in direct engagement with the upper surface of the keybed.

13. A keyboard device as claimed in claim 10, wherein the keyframe front and the keyframe center are discontiguous structures with respect to each other.