Patent US3545821A successfully refreshed from Google Patents.
Patent US3862449A successfully refreshed from Google Patents.
US3862449A
Expired / Lapsed
US
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Ion sleeve for arc lamp electrode
Assignee: Excelitas Technologies Illumination Inc
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Filing: 1973-07-25
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Granted: 1975-01-21
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Expires: 1993-07-25
Abstract
Abstract The voltage required to initiate an arc across the electrode gap in a gas-filled arc lamp can be significantly reduced by providing a refractory metal sleeve overhanging the tapered end of one of the electrodes. The direction and extent of the overhang must be such that the electric field strength at the distal end of the overhanging portion of the sleeve is greater than at the apex of the electrode to which the sleeve is affixed.
Inventors
- 👤 William R Stuart
- 👤 Donald H Preist
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:01
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/84; H01J61/86; H01J61/02; H01J61/04; H01J61/98
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
135 words
An arc lamp comprising an envelope for confining an ionizable gas, a reflector in said envelope, first and second electrodes mounted within said envelope on a common axis and being separated from each other along said axis in non-overlapping arrangement to form an arc gap between the facing ends of said electrodes, said first electrode having a generally conical surface at its end which faces the opposite electrode, said common axis being substantially parallel to the direction taken by light reflected from said reflector, said first electrode also having a projecting portion which extends from the base of said conical surface toward said gap, whereby an electrical potential between said electrodes will establish an electrical field which is greater at the distal end of said projecting portion than at the apex of said first electrode.
Claim 2
Dependent Claim
135 words
An arc lamp comprising an envelope for confining an ionizable gas, a reflector in said envelope, first and second electrodes mounted within said envelope on a common axis and being separated from each other along said axis in non-overlapping arrangement to form an arc gap between the facing ends of said electrodes, said first electrode having a generally conical surface at its end which faces the opposite electrode, said common axis being substantially parallel to the direction taken by light reflected from said reflector, said first electrode also having a projecting portion which extends from the base of said conical surface toward said gap, whereby an electrical potential between said electrodes will establish an electrical field which is greater at the distal end of said projecting portion than at the apex of said first electrode.
Claim 3
Dependent Claim
26 words
The arc lamp of claim 1 wherein said projecting portion comprises a sleeve forming a continuous annular surface at its end which projects toward said gap.
Claim 4
Dependent Claim
15 words
The arc lamp of claim 1 wherein said projecting portion extends parallel to said axis.
Claim 5
Dependent Claim
48 words
The arc lamp of claim 1 wherein said arc gap, said reflector, and the projecting end of said projecting portion are positioned relative to each other such that said projecting end of said projecting portion intercepts no light from said arc which would otherwise fall on said reflector.
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) | 1978-01-20 | 1978-07-22 | 1979-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-20 | 1982-07-22 | 1983-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-20 | 1986-07-22 | 1987-01-21 | $7700.00 | Window Closed / Lapsed |