FR991650A
Expired / Lapsed
FR
⏱️ 0.0 years remaining
Differential microphones
Assignee: SIF Societe Independante de Telegraphie Sans Fil
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Filing: 1944-04-21
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Granted: 1951-10-08
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Expires: 1964-04-21
Abstract
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Inventors
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Bibliographic Details
Application Number
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Jurisdiction
FR
Data Source
google_patents
Last Synchronized
2026-11-01 18:54
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/02; H04M1/19; H04R; H04R9/00; H04R9/08
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