US4002939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric lamp
Assignee: US Philips Corp
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Filing: 1976-03-03
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Granted: 1977-01-11
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Expires: 1996-03-03
Abstract
Abstract Electric lamps according to the invention have inner current conductors with a molybdenum part which is welded to the molybdenum foil in the pinch of the quartz glass lamp vessel and a tungsten part which supports the electrode or the filament and is connected to the molybdenum part by a butt weld. As a result of this construction reject and production disturbances upon making the welded joint between the molybdenum foil and the inner current conductor which occur when tungsten current conductors are used are avoided.
Inventors
- 👤 Johannes Maria Van Bragt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:10
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/36; H01J61/366
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
80 words
An electric lamp having a quartz glass lamp vessel with gas filling and pinched seal, in which seal a molybdenum foil is incorporated to which an outer current conductor and an inner current conductor are welded, characterized in that the inner current conductor, at least at the area of the welded joint at the molybdenum foil, consists of a molybdenum part which is butt welded to a part which mainly consists of tungsten and extends further in the lamp vessel.
Claim 2
Dependent Claim
80 words
An electric lamp having a quartz glass lamp vessel with gas filling and pinched seal, in which seal a molybdenum foil is incorporated to which an outer current conductor and an inner current conductor are welded, characterized in that the inner current conductor, at least at the area of the welded joint at the molybdenum foil, consists of a molybdenum part which is butt welded to a part which mainly consists of tungsten and extends further in the lamp vessel.
Claim 3
Dependent Claim
32 words
An electric lamp as claimed in claim 1, characterized in that the butt weld between the molybdenum part and the tungsten part of the inner current conductor is present within the pinch.
Claim 4
Dependent Claim
27 words
An electric lamp as claimed in claim 2, characterized in that the butt weld is present near the end of the molybdenum foil facing the lamp vessel.
References Cited (Backward Citations)
GB580276A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-11 | 1980-07-12 | 1981-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-11 | 1984-07-12 | 1985-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-11 | 1988-07-12 | 1989-01-11 | $7700.00 | Window Closed / Lapsed |