US4297611A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control of tungsten filament erosion in a halogen lamp
Assignee: Cooper Industries LLC
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Filing: 1979-10-02
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Granted: 1981-10-27
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Expires: 1999-10-02
Abstract
Abstract The present invention is directed to an incandescent lamp having tungsten filaments and halogen gas in the lamp enclosure wherein an inoperative surrogate tungsten filament is incorporated to reduce the tendency for active halogen gas to attack the filament and other metal parts within the lamp enclosure.
Inventors
- 👤 Salvatore F. Cortorillo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:01
CPC Classifications
H; H01; H01K; H01K1/00; H01K1/26
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
118 words
In an incandescent lamp of the type having at least two operative tungsten filaments in a bulb enclosing an atmosphere containing a halogen gas, the improvement comprising an inoperative surrogate filament within said bulb comprising a tungsten surface positioned in a region near said tungsten filaments to passively receive chemical attack by said halogen gas whereby said operative tungsten filaments are at least partially protected from attack by said halogen gas and wherein said operative tungsten filaments have two support legs each, said inoperative surrogate filament comprises four tungsten wires, one each positioned near a support leg, each said tungsten wire separated a small distance from said support leg and extending substantially parallel to its associated support leg.
Claim 2
Dependent Claim
118 words
In an incandescent lamp of the type having at least two operative tungsten filaments in a bulb enclosing an atmosphere containing a halogen gas, the improvement comprising an inoperative surrogate filament within said bulb comprising a tungsten surface positioned in a region near said tungsten filaments to passively receive chemical attack by said halogen gas whereby said operative tungsten filaments are at least partially protected from attack by said halogen gas and wherein said operative tungsten filaments have two support legs each, said inoperative surrogate filament comprises four tungsten wires, one each positioned near a support leg, each said tungsten wire separated a small distance from said support leg and extending substantially parallel to its associated support leg.
Claim 3
Dependent Claim
88 words
An incandescent lamp comprising: (a) a lamp enclosure enclosing therein a halogen gas; (b) two selectably operative tungsten filaments disposed within said enclosure; (c) each operative tungsten filament having at least one support leg for support within said enclosure; (d) an inoperative surrogate element in said enclosure for passively receiving chemical attack by said halogen gas; (e) said inoperative surrogate element comprising a plurality of tungsten elements, one each said tungsten element being disposed, respectively, in close proximity to each said support leg but not in contact therewith.
Claim 4
Dependent Claim
88 words
An incandescent lamp comprising: (a) a lamp enclosure enclosing therein a halogen gas; (b) two selectably operative tungsten filaments disposed within said enclosure; (c) each operative tungsten filament having at least one support leg for support within said enclosure; (d) an inoperative surrogate element in said enclosure for passively receiving chemical attack by said halogen gas; (e) said inoperative surrogate element comprising a plurality of tungsten elements, one each said tungsten element being disposed, respectively, in close proximity to each said support leg but not in contact therewith.
Claim 5
Dependent Claim
13 words
The incandescent lamp of claim 2 wherein said tungsten elements are tungsten wires.
Claim 6
Dependent Claim
31 words
The incandescent lamp of claim 3 wherein each said tungsten wire is parallel to and slightly separated from its associated support leg substantially along the entire length of the support leg.
Claim 7
Independent Claim
64 words
A method for protecting tungsten parts within a lamp enclosure of an incandescent lamp having two operative tungsten filaments and a halogen gas therein comprising the step of positioning an inoperative surrogate element having an exposed tungsten surface within the lamp enclosure, said tungsten surface being adapted to remain below the temperature at which it will emit visible light during operation of the lamp.
Claim 8
Independent Claim
64 words
A method for protecting tungsten parts within a lamp enclosure of an incandescent lamp having two operative tungsten filaments and a halogen gas therein comprising the step of positioning an inoperative surrogate element having an exposed tungsten surface within the lamp enclosure, said tungsten surface being adapted to remain below the temperature at which it will emit visible light during operation of the lamp.
Claim 9
Independent Claim
69 words
A method for protecting a non-operating filament of a pair of selectably operating tungsten filaments in a lamp enclosure having a halogen gas therein comprising the step of positioning an inoperative surrogate element having an exposed tungsten surface in the proximity of the selectably operating filaments, said exposed tungsten surface being adapted to remain below the temperature at which it will emit visible light during operation of the lamp.
Claim 10
Independent Claim
69 words
A method for protecting a non-operating filament of a pair of selectably operating tungsten filaments in a lamp enclosure having a halogen gas therein comprising the step of positioning an inoperative surrogate element having an exposed tungsten surface in the proximity of the selectably operating filaments, said exposed tungsten surface being adapted to remain below the temperature at which it will emit visible light during operation of the lamp.
Claim 11
Dependent Claim
18 words
The method of claim 6 wherein the surrogate element is positioned parallel to the pair of tungsten filaments.
Claim 12
Dependent Claim
16 words
The method of claim 7 wherein the surrogate element is positioned between the operative tungsten filaments.
Claim 13
Dependent Claim
13 words
The method of claim 8 wherein the surrogate element is a tungsten wire.
Claim 14
Dependent Claim
23 words
The method of claim 9 wherein the tungsten wire portion between the operative tungsten elements is formed in the shape of a sawtooth.
Claim 15
Dependent Claim
13 words
The method of claim 7 wherein the surrogate element is a tungsten screen.
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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) | 1984-10-26 | 1985-04-27 | 1985-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-26 | 1989-04-27 | 1989-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-26 | 1993-04-27 | 1993-10-27 | $7700.00 | Window Closed / Lapsed |