US5874805A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrode structure including a rod comprising refractory metal and having a greater thermal conductivity material
Assignee: Digital Projection Ltd
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Filing: 1995-06-30
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Granted: 1999-02-23
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Expires: 2015-06-30
Abstract
Abstract An electrode structure for use in a sealed arc lamp is described. The electrode structure includes a tungsten containing rod surrounded by a block of sintered tungsten containing powder. The block may be impregnated with a thermally conductive material such as copper, silver or braze, and may have a high thermal emissivity surface.
Inventors
- 👤 Martin Kavanagh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:12
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/04; H01J61/06; H01J61/073; H01J9/00; H01J9/02
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
48 words
An electrode structure comprising: a rod comprising refractory metal, part of which forms the arc seat of the electrode, the rod being at least partially surrounded by a sintered powder block, wherein the sintered block is impregnated with a material having a greater thermal conductivity than said powder.
Claim 2
Dependent Claim
48 words
An electrode structure comprising: a rod comprising refractory metal, part of which forms the arc seat of the electrode, the rod being at least partially surrounded by a sintered powder block, wherein the sintered block is impregnated with a material having a greater thermal conductivity than said powder.
Claim 3
Dependent Claim
13 words
A structure according to claim 1, in which the refractory metal is tungsten.
Claim 4
Dependent Claim
15 words
An electrode structure according to claim 2, wherein said powder comprises tungsten or tungsten carbide.
Claim 5
Dependent Claim
19 words
An electrode structure according to claim 2, wherein said block comprises a mixture of tungsten powder and copper powder.
Claim 6
Dependent Claim
20 words
An electrode according to claim 4, wherein said powder comprises between 60% to 80% tungsten and 40% to 20% copper.
Claim 7
Dependent Claim
13 words
A structure according to claim 1, in which the refractory metal is molybdenum.
Claim 8
Dependent Claim
17 words
An electrode structure according to claim 1, wherein said greater thermal conductivity material is a brazable material.
Claim 9
Dependent Claim
16 words
An electrode structure according to claim 7, in which said greater thermal conductivity material is silver.
Claim 10
Dependent Claim
16 words
An electrode structure according to claim 7, in which said greater thermal conductivity material is copper.
Claim 11
Dependent Claim
19 words
An electrode structure according to claim 1, wherein said block is etched so as to expose the sintered material.
Claim 12
Dependent Claim
20 words
An electrode structure according to claim 1, wherein the pores of said block are in-filled with an ignition enhancement material.
Claim 13
Dependent Claim
15 words
An electrode structure according to claim 11, wherein said ignition enhancement material is thorium oxide.
Claim 14
Dependent Claim
28 words
An electrode structure according to claim 1, wherein the sintered block includes pores, at least some of said pores being in-filled with grains of a thermally emissive material.
Claim 15
Dependent Claim
18 words
An electrode structure according to claim 13, wherein said thermally emissive material is manganese oxide or tungsten carbide.
Claim 16
Dependent Claim
11 words
An arc lamp including an electrode structure according to claim 1.
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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) | 2002-02-22 | 2002-08-24 | 2003-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-22 | 2006-08-24 | 2007-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-22 | 2010-08-24 | 2011-02-23 | $7700.00 | Window Closed / Lapsed |