US4052635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric discharge lamp
Assignee: US Philips Corp
•
Filing: 1976-09-27
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Granted: 1977-10-04
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Expires: 1996-09-27
Abstract
Abstract Electric discharge lamps having a ceramic lamp vessel and current leadthroughs of niobium or tantalum cannot be operated in a nitrogen-containing atmosphere or in air due to attack of the current leadthroughs by the surrounding gas. According to the invention, those parts of the current leadthroughs which during operation have a temperature of more than 500° C and more than 350° C, respectively, are screened from the surrounding gas by means of ceramic mouldings which are connected to the current leadthrough in a gas-tight manner by means of sealing material. As a result of this the lamps according to the invention can be operated in a nitrogen-containing atmosphere and in air respectively.
Inventors
- 👤 Cornelis Adrianus Joannes Jacobs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:38
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/36
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
104 words
An electric discharge lamp having a ceramic lamp vessel in the wall of which are incorporated cylindrical current leadthroughs of niobium or tantalum which are connected at one end to the electrodes and project at the other beyond the lamp vessel, means being present to protect the leadthroughs against attack by gas surrounding the lamp vessel, wherein the parts of the current leadthroughs which during operation have a temperature of more than 500° C are screened from the gas surrounding the lamp vessel by means of ceramic mouldings which are connected in a gas-tight manner to the current leadthroughs by means of sealing material.
Claim 2
Dependent Claim
104 words
An electric discharge lamp having a ceramic lamp vessel in the wall of which are incorporated cylindrical current leadthroughs of niobium or tantalum which are connected at one end to the electrodes and project at the other beyond the lamp vessel, means being present to protect the leadthroughs against attack by gas surrounding the lamp vessel, wherein the parts of the current leadthroughs which during operation have a temperature of more than 500° C are screened from the gas surrounding the lamp vessel by means of ceramic mouldings which are connected in a gas-tight manner to the current leadthroughs by means of sealing material.
Claim 3
Dependent Claim
57 words
An electric discharge lamp as claimed in claim 1, wherein the parts of the current leadthroughs which during operation have a temperature of more than 350° C are screened from the gas surrounding the lamp vessel by means of ceramic mouldings which are connected to the current leathroughs in a gas-tight manner by means of sealing material.
Claim 4
Dependent Claim
24 words
An electric discharge lamp as claimed in claim 1 wherein said current leadthroughs are hollow for at least a portion of the extent thereof.
Claim 5
Dependent Claim
28 words
An electric discharge lamp as claimed in claim 1 wherein said lamp vessel cylindrical and said ceramic sleeves form one unit with end seals of said lamp vessel.
References Cited (Backward Citations)
US3855495A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |