Patent US4474100A successfully refreshed from Google Patents.
US4474100A
Expired / Lapsed
US
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Musical keyboard
Assignee: Nippon Gakki Co Ltd
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Filing: 1982-06-15
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Granted: 1984-10-02
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Expires: 2002-06-15
Abstract
Abstract A musical keyboard includes a key bed having fulcrums formed therein, a row of keys each having a supported portion located at the rear end thereof for pivotal contact with the corresponding fulcrum for vertical swinging between a rest position and an operative position, and a resilient device for urging the keys upwards to said rest position. The resilient device has a leaf spring positioned below the keys and secured to the key bed to extend substantially horizontally towards the fulcrums, the free end of said leaf spring engaging the lower surface of each key to urge the key upwards.
Inventors
- 👤 Masao Kondo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:27
CPC Classifications
G; G10; G10C; G10C3/00; G10C3/12; G10H; G10H1/00; G10H1/32; G10H1/34; G10H1/344
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
147 words
In a musical keyboard of the type which includes a frame means having fulcrums formed therein, a row of elongated keys each having a supported portion located at a rear end thereof for pivotal contact with a corresponding fulcrum of said frame means for vertical swinging between a rest position and an operative position and resilient means for urging the keys upwards to said rest position, the improvement wherein the resilient means comprises a leaf spring positioned below the keys and secured to the frame means to have a free end extend substantially horizontally towards the fulcrums, the free end of said leaf spring engages a lower surface of each said key to urge the key upwards, and wherein said supported portion extends downwardly from said rear end of the key, and said leaf spring engages at the free end the lower surface of the supported portion.
Claim 2
Dependent Claim
147 words
In a musical keyboard of the type which includes a frame means having fulcrums formed therein, a row of elongated keys each having a supported portion located at a rear end thereof for pivotal contact with a corresponding fulcrum of said frame means for vertical swinging between a rest position and an operative position and resilient means for urging the keys upwards to said rest position, the improvement wherein the resilient means comprises a leaf spring positioned below the keys and secured to the frame means to have a free end extend substantially horizontally towards the fulcrums, the free end of said leaf spring engages a lower surface of each said key to urge the key upwards, and wherein said supported portion extends downwardly from said rear end of the key, and said leaf spring engages at the free end the lower surface of the supported portion.
Claim 3
Dependent Claim
48 words
The musical keyboard as recited in claim 1, wherein the key comprises further a key lock projecting downwards from said lower surface of said supported portion, whereby the free end of said leaf spring abuts against said key lock to prevent a longitudinal movement of the elongated key.
Claim 4
Dependent Claim
25 words
The musical keyboard as recited in claim 1, wherein said supported portion is provided with a lateral groove engaging said fulcrum for pivotal contact therewith.
Claim 5
Dependent Claim
51 words
The musical keyboard as recited in claim 3, wherein the frame means is provided with an opening for passing said supported portion therethrough, a rearside periphery of said opening forming said fulcrum, and wherein a fixed end of said leaf spring is fastened to the lower surface of the key bed.
Claim 6
Dependent Claim
50 words
The musical keyboard as recited in claim 4, wherein the key further comprises a generally L-shaped stopper extending downwardly from the key and having a horizontal leg, said horizontal leg normally engaging the frame means for holding the key in said rest position with the aid of said leaf spring.
Claim 7
Dependent Claim
60 words
The musical keyboard as recited in claim 5, further comprising an elongated key switch holder fastened to the lower surface of the frame means and having key guide means for guiding an up-down movement of said stoppers, and said horizontal leg having an actuator for actuating a key switch mounted on said key switch holder when the key is depressed.
Claim 8
Dependent Claim
52 words
The musical keyboard as recited in claim 6, wherein said key switch holder is provided with an elongated spring holding member integrally formed therewith and extending longitudinally of said key switch holder, said spring holding member fastening the fixed end of said leaf spring to the frame means in a sandwich manner.
Claim 9
Dependent Claim
149 words
In a musical keyboard of the type which includes a frame having fulcrums formed therein, a row of elongated keys each having a supported portion located at a rear end thereof for pivotal contact with a corresponding fulcrum of said frame means for vertical swinging between a rest position and an operative position and resilient means for urging the keys upwards to said rest position, the improvement wherein the resilient means comprises a leaf spring positioned below the keys and secured to the frame means to have a free end extend substantially horizontally towards the fulcrums, the free end of said leaf spring engaging a lower surface of each said key to urge the key upwards, and wherein said leaf spring is of a comb shape having teeth the number of which corresponds to the number of the keys, the free ends of said teeth engaging the respective keys.
Claim 10
Dependent Claim
149 words
In a musical keyboard of the type which includes a frame having fulcrums formed therein, a row of elongated keys each having a supported portion located at a rear end thereof for pivotal contact with a corresponding fulcrum of said frame means for vertical swinging between a rest position and an operative position and resilient means for urging the keys upwards to said rest position, the improvement wherein the resilient means comprises a leaf spring positioned below the keys and secured to the frame means to have a free end extend substantially horizontally towards the fulcrums, the free end of said leaf spring engaging a lower surface of each said key to urge the key upwards, and wherein said leaf spring is of a comb shape having teeth the number of which corresponds to the number of the keys, the free ends of said teeth engaging the respective keys.
Claim 11
Dependent Claim
48 words
The musical keyboard as recited in claim 8, wherein the key comprises further a key lock projecting downwards from said lower surface of said supported portion, whereby the free end of said leaf spring abuts against said key lock to prevent a longitudinal movement of the elongated key.
Claim 12
Dependent Claim
25 words
The musical keyboard as recited in claim 8, wherein said supported portion is provided with a lateral groove engaging said fulcrum for pivotal contact therewith.
Claim 13
Dependent Claim
51 words
The musical keyboard as recited in claim 10, wherein the frame means is provided with an opening for passing said supported portion therethrough, a rearside periphery of said opening forming said fulcrum, and wherein a fixed end of said leaf spring is fastened to the lower surface of the key bed.
Claim 14
Dependent Claim
50 words
The musical keyboard as recited in claim 11, wherein the key further comprises a generally L-shaped stopper extending downwardly from the key and having a horizontal leg, said horizontal leg normally engaging the frame means for holding the key in said rest position with the aid of said leaf spring.
Claim 15
Dependent Claim
60 words
The musical keyboard as recited in claim 12, further comprising an elongated key switch holder fastened to the lower surface of the frame means and having key guide means for guiding an up-down movement of said stoppers, and said horizontal leg having an actuator for actuating a key switch mounted on said key switch holder when the key is depressed.
Claim 16
Dependent Claim
52 words
The musical keyboard as recited in claim 13, wherein said key switch holder is provided with an elongated spring holding member integrally formed therewith and extending longitudinally of said key switch holder, said spring holding member fastening the fixed end of said leaf spring to the frame means in a sandwich manner.
References Cited (Backward Citations)
US2565239A
Cited
US3570359A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-02 | 1988-04-02 | 1988-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-02 | 1992-04-02 | 1992-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-02 | 1996-04-02 | 1996-10-02 | $7700.00 | Window Closed / Lapsed |