US3868528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quartz pinches containing sealant glass
Assignee: General Electric Co
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Filing: 1974-01-14
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Granted: 1975-02-25
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Expires: 1994-01-14
Abstract
Abstract In quartz envelopes for high pressure metal vapor lamps, improved pinch seals contain a glass sealant filling voids between the quartz and the tungsten electrode shank extending into the envelope. Prior to pinching, the tungsten shank is coated with a thin layer of substantially alkali-free glass having a coefficient of expansion intermediate that of tungsten and quartz. During pinching, the glass coating flows and fills the cavity which forms about the shank and extends from the sealing foil into the discharge space. Advantages include reduced shaling of quartz about the shank, less devitrification of quartz between main and starter electrode, and reduced attack of the shank by the metal halide.
Inventors
- 👤 William H Lake
- 👤 Gene I Thomasson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:56
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/36; H01J61/366
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
227 words
An electric lamp comprising: a quartz tube envelope having refractory metal inleads pinchsealed into its ends of the kind comprising an outer terminal lead, an intermediate sealing foil, and an inner lead extending into said envelope, said inner and outer leads being connected to opposite ends of said foil, and a sealing glass bonded to said inner lead and filling the crevice in the quartz around said inner lead extending from said foil into said envelope, said sealing glass being substantially alkali-free and having a coefficient of expansion intermediate that of quartz and that of said inner lead. 8. the method of pinch-sealing a quartz arc tube which includes: making a refractory metal inlead-foil-shank assembly comprising an outer terminal lead, an intermediate sealing foil and an inner shank, applying to said inner shank a sheath of substantially alkalifree sealing glass having a coefficient of expansion intermediate that of quartz and that of said inner lead, standing said assembly upright with the glass-sheathed shank uppermost and surrounding it by the lower end of a quartz tube, heating the lower end of said quartz tube to plasticity while filled with inactive gas, and quickly compressing the tube end to collapse it and hermetically unite the quartz to said intermediate sealing foil while causing said sealing glass to flow and fill a crevice in the quartz around the inner shank.
Claim 2
Dependent Claim
227 words
An electric lamp comprising: a quartz tube envelope having refractory metal inleads pinchsealed into its ends of the kind comprising an outer terminal lead, an intermediate sealing foil, and an inner lead extending into said envelope, said inner and outer leads being connected to opposite ends of said foil, and a sealing glass bonded to said inner lead and filling the crevice in the quartz around said inner lead extending from said foil into said envelope, said sealing glass being substantially alkali-free and having a coefficient of expansion intermediate that of quartz and that of said inner lead. 8. the method of pinch-sealing a quartz arc tube which includes: making a refractory metal inlead-foil-shank assembly comprising an outer terminal lead, an intermediate sealing foil and an inner shank, applying to said inner shank a sheath of substantially alkalifree sealing glass having a coefficient of expansion intermediate that of quartz and that of said inner lead, standing said assembly upright with the glass-sheathed shank uppermost and surrounding it by the lower end of a quartz tube, heating the lower end of said quartz tube to plasticity while filled with inactive gas, and quickly compressing the tube end to collapse it and hermetically unite the quartz to said intermediate sealing foil while causing said sealing glass to flow and fill a crevice in the quartz around the inner shank.
Claim 3
Dependent Claim
31 words
An electric lamp as in claim 1 wherein the inner lead extending into the envelope is tungsten, and said sealing glass has a coefficient of expansion close to that of tungsten.
Claim 4
Dependent Claim
23 words
An electric lamp as in claim 2 wherein the sealing glass has a softening point temperature in the range from 900* to 1,200*C.
Claim 5
Dependent Claim
119 words
An electric discharge arc tube comprising: a quartz tube envelope having inleads pinch-sealed into its ends of the kind comprising an outer terminal lead, an intermediate molybdenum sealing foil, and an inner tungsten lead extending into said envelope, said inner and outer leads being connected to opposite ends of said foil and said inner lead having an electrode at its distal end, a sealing glass bonded to said inner lead and filling the crevice in the quartz around said inner lead extending from said foil into said envelope, said sealing glass being substantially alkali-free and having a coefficient of expansion intermediate that of quartz and tungsten, and an ionizable filling in an envelope including an excess of vaporizable metal.
Claim 6
Dependent Claim
119 words
An electric discharge arc tube comprising: a quartz tube envelope having inleads pinch-sealed into its ends of the kind comprising an outer terminal lead, an intermediate molybdenum sealing foil, and an inner tungsten lead extending into said envelope, said inner and outer leads being connected to opposite ends of said foil and said inner lead having an electrode at its distal end, a sealing glass bonded to said inner lead and filling the crevice in the quartz around said inner lead extending from said foil into said envelope, said sealing glass being substantially alkali-free and having a coefficient of expansion intermediate that of quartz and tungsten, and an ionizable filling in an envelope including an excess of vaporizable metal.
Claim 7
Dependent Claim
23 words
An arc tube as in claim 4 wherein said sealing glass has a softening point temperature in the range from 900* to 1,200*C.
Claim 8
Dependent Claim
41 words
An arc tube as in claim 5 wherein said ionizable filling includes sodium iodide in excess of the quantity vaporized in operation and said arc tube has an additional inlead pinch-sealed into one end which terminates in an auxiliary starting electrode.
Claim 9
Dependent Claim
17 words
An arc tube as in claim 5 wherein said ionizable filling comprises ZnI2, LiI, T1I and GaI3.
Claim 10
Dependent Claim
22 words
The method of claim 8 wherein said glass sheath is applied to said inner shank as a thin fired-on layer of glass.
Claim 11
Dependent Claim
16 words
The method of claim 8 wherein after compressing, the tube end is heated to anneal it.
References Cited (Backward Citations)
US3785019A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |