Patent US4512234A successfully refreshed from Google Patents.
US4512234A
Expired / Lapsed
US
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Keyboard device having cushioned weight member for electronic musical instrument
Assignee: Nippon Gakki Co Ltd
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Filing: 1983-01-25
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Granted: 1985-04-23
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Expires: 2003-01-25
Abstract
Abstract Each key of a keyboard of an electronic musical instrument is mounted on a frame to be tiltable in the vertical direction and biased to a normal position by a return spring. Each key is incorporated with a weight member embedded in a cushion member. Preferably the cushioned weight member is mounted on the front end of each key and the cushion member is made of rubber. The cushioned weight member provides a refined responsive key touch sensation.
Inventors
- 👤 Shinji Kumano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:22
CPC Classifications
G; G10; G10H; G10H1/00; G10H1/32; G10H1/34; G10H1/344; G10C; G10C3/00; G10C3/12
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
166 words
A keyboard device of an electronic musical instrument comprising a plurality of keys each mounted on a frame to be tiltable in the vertical direction between a predetermined upper rest position and a predetermined lower rest position; biasing means for resiliently biasing each of said plurality of keys to its predetermined upper rest position; a weight member incorporated in each of said plurality of keys for adding a predetermined weight to each of said plurality of keys; and a cushion means disposed in each of said plurality of keys for elastically suspending said weight member from each of said plurality of keys toward said predetermined upper rest position and toward said predetermined lower rest position of each of said plurality of keys, said cushion means retarding both an action of each of said plurality of keys against said weight member at the start of key depression and a reaction of said weight member against each of said plurality of keys at the end of key depression.
Claim 2
Dependent Claim
166 words
A keyboard device of an electronic musical instrument comprising a plurality of keys each mounted on a frame to be tiltable in the vertical direction between a predetermined upper rest position and a predetermined lower rest position; biasing means for resiliently biasing each of said plurality of keys to its predetermined upper rest position; a weight member incorporated in each of said plurality of keys for adding a predetermined weight to each of said plurality of keys; and a cushion means disposed in each of said plurality of keys for elastically suspending said weight member from each of said plurality of keys toward said predetermined upper rest position and toward said predetermined lower rest position of each of said plurality of keys, said cushion means retarding both an action of each of said plurality of keys against said weight member at the start of key depression and a reaction of said weight member against each of said plurality of keys at the end of key depression.
Claim 3
Dependent Claim
32 words
A keyboard device according to claim 1 wherein said cushion means comprises a molded article of natural or synthetic rubber interposed between said weight member and each of said plurality of keys.
Claim 4
Dependent Claim
16 words
A keyboard device according to claim 1 wherein said cushion means comprises a foamed synthetic resin.
Claim 5
Dependent Claim
17 words
A keyboard device according to claim 1 wherein said cushion means comprises at least one spring means.
Claim 6
Dependent Claim
14 words
A keyboard device according to claim 1 wherein said cushion means comprises viscous liquid.
Claim 7
Dependent Claim
37 words
A keyboard device according to claim 2 wherein said cushion means comprises rubber and is supported through pins extending between side walls of each of said plurality of keys, said cushion means holding therein said weight member.
Claim 8
Dependent Claim
28 words
A keyboard device according to claim 2 wherein said cushion means which holds said weight member is maintained in frictional contact with each of said plurality of keys.
Claim 9
Dependent Claim
28 words
A keyboard device according to claim 6 wherein said weight member is supported by opposing side walls of each of said plurality of keys through said cushion means.
Claim 10
Dependent Claim
18 words
A keyboard device according to claim 1 wherein each of said plurality of keys has a cantilever construction.
Claim 11
Dependent Claim
24 words
A keyboard device according to claim 9 wherein said weight member is disposed at a front end of each of said plurality of keys.
Claim 12
Dependent Claim
48 words
A keyboard device according to claim 1 wherein each of said plurality of keys has a see-saw construction in which each said plurality of keys is supported by a fulcrum on said frame at around an intermediate point along the length of each of said plurality of keys.
Claim 13
Dependent Claim
24 words
A keyboard device according to claim 11 wherein said weight member is mounted on a front end of each of said plurality of keys.
Claim 14
Dependent Claim
24 words
A keyboard device according to claim 11 wherein said weight member is mounted on a rear end of each of said plurality of keys.
Claim 15
Dependent Claim
55 words
A keyboard device according to claim 9 wherein said biasing means comprises a leaf spring with its one end supported by a surface of each of said plurality of keys and its other end supported by said frame, said leaf spring undergoing buckling when each of said plurality of keys is in a normal position.
Claim 16
Dependent Claim
30 words
A keyboard device according to claim 1 wherein said cushion means comprises an elastic body and said weight member takes the form of metal powder dispersed in said elastic body.
Claim 17
Dependent Claim
29 words
A keyboard device according to claim 1 wherein said cushion means comprises viscous liquid and said weight member takes the form of metal powder dispersed in said viscous liquid.
References Cited (Backward Citations)
US130457A
Cited
JPS4910810A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-22 | 1988-10-22 | 1989-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-22 | 1992-10-22 | 1993-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-22 | 1996-10-22 | 1997-04-23 | $7700.00 | Window Closed / Lapsed |