US2583732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metallic carbides used as microphone resistance granules
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1950-05-08
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Granted: 1952-01-29
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Expires: 1970-05-08
Abstract
No abstract record available.
Inventors
- 👤 Ericsson Eric Arvid
- 👤 Jorgensen Anders Ossian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:14
CPC Classifications
H; H04; H04R; H04R21/00; H04R21/02; H04R21/021
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
13 words
A MICROPHONE CONTAINING AS THE PRESSUREDEPENDENT ELECTRICAL RESISTANCE, GRANULES OF A METAL CARBIDE.
Claim 2
Dependent Claim
13 words
A MICROPHONE CONTAINING AS THE PRESSUREDEPENDENT ELECTRICAL RESISTANCE, GRANULES OF A METAL CARBIDE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-01-28 | 1955-07-30 | 1956-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-01-28 | 1959-07-30 | 1960-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-01-28 | 1963-07-30 | 1964-01-29 | $7700.00 | Window Closed / Lapsed |