Patent US4728528A successfully refreshed from Google Patents.
Patent US2451818A successfully refreshed from Google Patents.
Patent CH299178A successfully refreshed from Google Patents.
CH299178A
Expired / Lapsed
CH
⏱️ 0.0 years remaining
A suitable room ventilation device for recovering heat from the exhaust air to preheat the fresh air.
Assignee: Studer Hans
•
Filing: 1950-06-19
•
Granted: —
•
Expires: 1970-06-19
Abstract
No abstract record available.
Inventors
- 👤 Studer Hans
Bibliographic Details
Application Number
—
Jurisdiction
CH
Data Source
google_patents
Last Synchronized
2026-11-01 09:52
CPC Classifications
F; F24; F24F; F24F12/00; F24F12/001; Y; Y02; Y02B; Y02B30/00; Y02B30/56
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.