US4262231A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helical wire coil in solenoidal lamp tip-off region wetted by alloy forming an amalgam with mercury
Assignee: General Electric Co
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Filing: 1978-10-25
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Granted: 1981-04-14
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Expires: 1998-10-25
Abstract
Abstract A lead-tin-bismuth alloy is disposed within a solenoidal electric field lamp to control the mercury vapor pressure. In accordance with one embodiment of the present invention, the alloy is placed within the tip-off region of the lamp envelope. The alloy is fixed within the tip-off region by a means of wetting the alloy to a metal wire structure such as a helix or a cylindrical screen. Alternatively, the alloy may be placed on an interior surface of the envelope by first wetting the glass with a layer of indium. Additionally, methods for wetting the lead-tin-bismuth alloy to the metal wire include firing the alloy in contact with the wire in a hydrogen atmosphere at a sufficiently high temperature to wet the alloy to the wire. The present invention permits the control of mercury vapor pressure in solenoidal electric field discharge lamps.
Inventors
- 👤 John M. Anderson
- 👤 Peter D. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:08
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/38; H01J9/395; H01J65/00; H01J65/04; H01J65/042; H01J65/048; H01J7/00; H01J7/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
112 words
In a solenoidal electric field discharge lamp including an evacuable, light-transmissive envelope with interior phosphor coat, said envelope containing a gaseous discharge medium, at least a portion of which is mercury vapor, with an electrically energized toroidal magnetic core disposed within the said medium, said core being electrically connected to a ballast located at a base end of said lamp, said envelope possessing a protruding tip-off region extending into the volume occupied by said ballast, the improvement comprising: an alloy wetted to a helical wire coil disposed within said tip-off region and forming an alloy with mercury within said envelope, so that the mercury vapor pressure in said discharge medium is controlled.
Claim 2
Dependent Claim
112 words
In a solenoidal electric field discharge lamp including an evacuable, light-transmissive envelope with interior phosphor coat, said envelope containing a gaseous discharge medium, at least a portion of which is mercury vapor, with an electrically energized toroidal magnetic core disposed within the said medium, said core being electrically connected to a ballast located at a base end of said lamp, said envelope possessing a protruding tip-off region extending into the volume occupied by said ballast, the improvement comprising: an alloy wetted to a helical wire coil disposed within said tip-off region and forming an alloy with mercury within said envelope, so that the mercury vapor pressure in said discharge medium is controlled.
Claim 3
Dependent Claim
27 words
The lamp of claim 1 in which the wire coil is positionally indexed from said core by means of a straight wire portion extending from said helix.
Claim 4
Dependent Claim
53 words
The lamp of claim 1 in which said wire coil possesses a diameter smaller than the diameter of the envelope in the tip-off region and said wire coil is maintained in a relatively fixed position by means of a curved, flexible tail extending from said helix and pressing against said tip-off region envelope.
Claim 5
Dependent Claim
20 words
The lamp of claim 1 in which said wire comprises material selected from the group consisting of nickel and steel.
Claim 6
Dependent Claim
17 words
The lamp of claim 1 in which said alloy comprises a mixture of lead, bismuth, and tin.
Claim 7
Dependent Claim
21 words
The lamp of claim 5 in which said lead, bismuth, and tin are present in the ratio of 32:52.5:15.5 atomic percent.
Claim 8
Dependent Claim
38 words
The lamp of claim 1 in which mercury and alloy are added to the lamp in amounts selected so as to maintain the mercury vapor pressure of an operating lamp at between approximately 5 and approximately 10 millitorr.
Claim 9
Dependent Claim
18 words
The lamp of claim 7 in which the mass of the mercury and alloy comprises approximately 100 mgs.
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) | 1984-04-13 | 1984-10-13 | 1985-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-13 | 1988-10-13 | 1989-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-13 | 1992-10-13 | 1993-04-14 | $7700.00 | Window Closed / Lapsed |