US3757158A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sodium vapor lamp having a grooved alumina arc tube
Assignee: GTE Sylvania Inc
•
Filing: 1972-06-23
•
Granted: 1973-09-04
•
Expires: 1992-06-23
Abstract
Abstract The arc tube of a sodium vapor arc discharge lamp has a spiral groove on the outer surface thereof. A refractory metal wire heater is wound around the arc tube and seated in the groove in order to maintain uniform spacing between the turns of the heater throughout the life of the lamp.
Inventors
- 👤 B Kopelman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:17
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/54; H01J61/541; H01J61/544
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
26 words
The lamp of claim 1 wherein the depth of said spiral groove is greater than about 50 percent of the diameter of said refractory metal wire.
Claim 2
Dependent Claim
27 words
The lamp of claim 1 wherein said heater is secured to said arc tube by means of short lengths of wire circumferentially wrapped around said arc tube.
Claim 3
Dependent Claim
27 words
The lamp of claim 3 wherein said arc tube has a plurality of circumferential grooves and said short lengths of wire are seated in said circumferential grooves.
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) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |