Patent US3798491A successfully refreshed from Google Patents.
US3798491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rounded end halogen lamp with spiral exhaust tube and method of manufacutre
Assignee: General Electric Co
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Filing: 1972-12-18
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Granted: 1974-03-19
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Expires: 1992-12-18
Abstract
Abstract An incandescent lamp of the tungsten-halogen type having an envelope of an aluminosilicate glass comprising in percent by weight SiO2 between 59 to 70, Al2O3 between 10 to 20 and BaO between 7.4 to 28 and having a coefficient of expansion between 36 and 40 X 10 7 per *C and a tungsten filament connected to lead wires which are directly sealed into the envelope. One end of the lamp envelope is rounded and the other end contains the seal and the tipped-off residue of an exhaust tube. Enclosed in the tipped-off residue is a spiral of tungsten wire which keeps the exhaust tube open during the lead wire sealing operation.
Inventors
- 👤 R Malm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:30
CPC Classifications
H; H01; H01K; H01K1/00; H01K1/28; C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/083; C03C3/085; H01K3/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
19 words
An incandescent lamp as claimed in claim 1 wherein said refractory metal lead wires and said spiral are tungsten.
Claim 2
Dependent Claim
18 words
An incandescent lamp as claimed in claim 1 wherein said rounded end of said envelope contains a lens.
Claim 3
Dependent Claim
16 words
An incandescent lamp as claimed in claim 1 wherein said halogen is a quantity of iodine.
Claim 4
Dependent Claim
23 words
An incandescent lamp as claimed in claim 4 wherein said refractory metal lead wires are molybdenum and said refractory metal spiral is tungsten.
Claim 5
Dependent Claim
22 words
An incandescent lamp as claimed in claim 5 wherein said iodine is added to the lamp in the form of methyl iodide.
Claim 6
Dependent Claim
20 words
An incandescent lamp as claimed in claim 6 wherein said quantity of iodine is equal to 1 percent by volume.
Claim 7
Independent Claim
168 words
A method of manufacturing an incandescent lamp comprising: a. inserting a refractory metal spiral into an exhaust tube, b. heating the exterior of the exhaust tube lightly in the area where the spiral is located, c. attaching a filament to refractory metal lead wires to form a mount, d. positioning said mount over said exhaust tube such that said lead wires straddle the exterior of said exhaust tube in the area of the refractory metal spiral, e. positioning a rounded end bulb over said mount and said exhaust tube, f. heating said envelope, lead wires, and the exhaust tube to seal the lead wires and the outer periphery of the exhaust tube to the bulb at the bulb''s open end to form a sealed lamp. g. flushing said sealed lamp with an inert gas to remove impurities, h. filling said lamp with a fill gas, i. heating said exhaust tube, to form a tipped sealed tube, at a location below said spiral to form a sealed exhausted lamp.
Claim 8
Dependent Claim
59 words
The method claimed in claim 8 wherein said heating and tipping operation is followed by cooling of said lamp at said rounded end so that said fill gas is condensed in the rounded end portion of the bulb, heating said tipped-off residue at a location near the end of said spiral to form a pressurized sealed and exhausted lamp.
Claim 9
Dependent Claim
29 words
The method claimed in claim 8 wherein said fill gas contains a halogen hydrocarbon and said heating and tipping operation is followed by cracking carbon from said halogen hydrocarbon.
References Cited (Backward Citations)
US2825040A
Cited
US3496401A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |