Patent US5000787A successfully refreshed from Google Patents.
Patent US4036732A successfully refreshed from Google Patents.
Patent DE477232C successfully refreshed from Google Patents.
DE477232C
Expired / Lapsed
DE
⏱️ 0.0 years remaining
An incandescent cathode for electron tubes made of difficult-to-melt metal, especially tungsten
Assignee: AEG AG
•
Filing: 1922-06-23
•
Granted: 1929-06-04
•
Expires: 1942-06-23
Abstract
No abstract record available.
Inventors
- 👤 Dr Ernst Friederich
- 👤 Dr Hans Rukop
- 👤 Dr Hellmut Simon
Bibliographic Details
Application Number
—
Jurisdiction
DE
Data Source
google_patents
Last Synchronized
2026-11-09 03:03
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/14
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.