Patent US3658719A successfully refreshed from Google Patents.
US3658719A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Smoke generating tube
Assignee: MSA Safety Inc
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Filing: 1969-10-09
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Granted: 1972-04-25
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Expires: 1989-10-09
Abstract
Abstract A SOLID ACID REAGENT AND A SOLID BASE REAGENT ARE SEPARATELY CONTAINED IN A BREAKABLE AMPOULE THAT IS ENCLOSED IN A PERFORATED ENVELOPE, WHICH IS IN TURN CONTAINED IN A PLIABLE TUBE. SMOKE IS GENERATED BY BREAKING THE AMPOULES AND PASSING AIR THROUGH THE TUBE.
Inventors
- 👤 Paul W Mcconnaughey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:52
CPC Classifications
C; C06; C06D; C06D3/00; F; F41; F41H; F41H9/00; F41H9/06
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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |