Patent US3335323A successfully refreshed from Google Patents.
US3335323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical apparatus and machines for protection against fire and explosion hazards
Assignee: W DAN BERGMAN AB
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Filing: 1965-03-29
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Granted: 1967-08-08
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Expires: 1985-03-29
Abstract
No abstract record available.
Inventors
- 👤 Molin Urban
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:49
CPC Classifications
H; H02; H02K; H02K9/00; H02K9/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
67 words
AN APPARATUS COMPRISING A SHORT-CIRCUITED ELECTRIC MOTOR WHICH HAS AT LEAST ITS STATOR CHAMBER SEALED OFF FROM THE AMBIENT ATMOSPHERE, A CHARGING CHAMBER CONNECTED BY A PASSAGE TO THE INTERIOR OF SAID STATOR CHAMBER, A SPRING-LOADED CHECK VALVE POSITIONED NORMALLY TO SHUT OFF SAID PASSAGE, MEANS FOR CHARGING SAID CHARGING CHAMBER WITH GAS UNDER PRESSURE AND A PRESSURE-SENSITIVE MEANS WITHIN SAID STATOR CHAMBER ADAPTED TO BREAK OFF
Claim 2
Independent Claim
67 words
AN APPARATUS COMPRISING A SHORT-CIRCUITED ELECTRIC MOTOR WHICH HAS AT LEAST ITS STATOR CHAMBER SEALED OFF FROM THE AMBIENT ATMOSPHERE, A CHARGING CHAMBER CONNECTED BY A PASSAGE TO THE INTERIOR OF SAID STATOR CHAMBER, A SPRING-LOADED CHECK VALVE POSITIONED NORMALLY TO SHUT OFF SAID PASSAGE, MEANS FOR CHARGING SAID CHARGING CHAMBER WITH GAS UNDER PRESSURE AND A PRESSURE-SENSITIVE MEANS WITHIN SAID STATOR CHAMBER ADAPTED TO BREAK OFF
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-08-07 | 1971-02-06 | 1971-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-08-07 | 1975-02-06 | 1975-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-08-07 | 1979-02-06 | 1979-08-08 | $7700.00 | Window Closed / Lapsed |