US3588868A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Status signalling system
Assignee: ELECTRO Tech APPLIANCE SERVICE
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Filing: 1969-02-27
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Granted: 1971-06-28
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Expires: 1989-02-27
Abstract
Abstract IN A ROOM STATUS SIGNALLING SYSTEM A SEPARATE SIGNALLING CIRCUIT IS PROVIDED FOR EACH ROOM, EACH SIGNALLING CIRCUIT INCLUDING A PLURALITY OF INDICATOR LAMPS IN SERIES AND BEING SELECTIVELY CONNECTABLE TO ALTERNATIVE SUPPLY TERMINALS BY MANUALLY OPERABLE SWITCHES AT THE ROOM AND AT A CENTRAL CONTROL DESK. THE ALTERNATIVE ELECTRICAL SUPPLIES ENERGIZE THE LAMPS TO PROVIDE A STEADY SIGNAL, A SLOW FLASHING SIGNAL, AND A FAST FLASHING SIGNAL.
Inventors
- 👤 William J Head
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:26
CPC Classifications
G; G08; G08B; G08B5/00; G08B5/22; G08B5/36
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-27 | 1974-12-27 | 1975-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-27 | 1978-12-27 | 1979-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-27 | 1982-12-27 | 1983-06-28 | $7700.00 | Window Closed / Lapsed |