US3753797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for heat treatment of metallic strings for stringed instruments
Assignee: Kawai Musical Instruments Manufacturing Co Ltd
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Filing: 1971-07-26
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Granted: 1973-08-21
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Expires: 1991-07-26
Abstract
Abstract A string of a stringed instrument is heat treated to a temperature less than its annealing or softening temperature under tensile stress to reduce residual stress in the string and thereby minimize tonal variation over long periods of time after the string has been strung in the instrument. The string is electrically heated, optionally after stringing in the instrument. The tensile stress is 40-160 kg/mm2 and the heating temperature is 150*-400*C.
Inventors
- 👤 H Fukuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:57
CPC Classifications
C; C21; C21D; C21D9/00; C21D9/52; C21D9/525; C21D8/00; C21D8/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
47 words
A process as claimed in claim 1 wherein the string is subjected to tensile stress by fixing the string at one end and applying a weight to its opposite end and the string is heated by passing an electrical current through an intermediate portion of its length.
Claim 2
Dependent Claim
21 words
A process as claimed in claim 1 comprising mounting the string in the piano before it is heated under tensile stress.
Claim 3
Dependent Claim
37 words
A process as claimed in claim 3 wherein the string is mounted in the piano by being connected to a tuning pin and a hitch pin, the piano wire being heated by passage of electrical current therethrough.
Claim 4
Dependent Claim
15 words
A process as claimed in claim 4 comprising electrically isolating the string in said instrument.
Claim 5
Dependent Claim
16 words
A process as claimed in claim 1 wherein the string is heat treated for 1 minute.
References Cited (Backward Citations)
US2281132A
Cited
US3196052A
Cited
US2932502A
Cited
US3068353A
Cited
US3469829A
Cited
US3580746A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |