Patent US2920222A successfully refreshed from Google Patents.
US2920222A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric lamp
Assignee: Duro Test Corp
•
Filing: 1957-08-13
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Granted: 1960-01-05
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Expires: 1977-08-13
Abstract
No abstract record available.
Inventors
- 👤 Thorington Luke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:49
CPC Classifications
B; B60; B60G; B60G11/00; B60G11/02; H; H01; H01K; H01K5/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
44 words
A LIGHT SOURCE COMPRISING AN EVACUATED LIGHT TRANSMITTING ENVELOPE, AN INCANDESCIBLE TUNGSTEN SOURCE OF RADIANT ENERGY IS SAID ENEVLOPE, A GAS OR VAPOR IN SAID ENVELOPE AT OR BELOW A PRESSURE OF 200 MILLIMETERS WHICH DISSOCIATES IN THE PRESENCE OF HOT TUNGSTEN, AND ANOTHER
Claim 2
Dependent Claim
44 words
A LIGHT SOURCE COMPRISING AN EVACUATED LIGHT TRANSMITTING ENVELOPE, AN INCANDESCIBLE TUNGSTEN SOURCE OF RADIANT ENERGY IS SAID ENEVLOPE, A GAS OR VAPOR IN SAID ENVELOPE AT OR BELOW A PRESSURE OF 200 MILLIMETERS WHICH DISSOCIATES IN THE PRESENCE OF HOT TUNGSTEN, AND ANOTHER
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-01-04 | 1963-07-06 | 1964-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-04 | 1967-07-06 | 1968-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-04 | 1971-07-06 | 1972-01-05 | $7700.00 | Window Closed / Lapsed |