DE600150C
Expired / Lapsed
DE
⏱️ 0.0 years remaining
Funnel loudspeaker with loosely coupled resonance structures
Assignee: KARL-LUDWIG RUPPEL
•
Filing: —
•
Granted: 1934-07-16
•
Expires: 1951-07-16
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
DE
Data Source
google_patents
Last Synchronized
2026-11-07 14:56
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/30; H04R1/28; H04R1/2869; H04R1/2892; H04R1/2896
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.