Patent US4409337A successfully refreshed from Google Patents.
US4409337A
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Glass envelopes for tungsten-halogen lamps
Assignee: Corning Glass Works
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Filing: 1982-11-12
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Granted: 1983-10-11
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Expires: 2002-11-12
Abstract
Abstract This invention is directed to glasses especially suitable for use as envelopes in tungsten-halogen lamps, those glasses exhibiting liquidus temperatures no higher than 1125° C., liquidus viscosities of at least 50,000 poises, coefficients of thermal expansion between about 42-46×10 -7 /°C., and consisting essentially, in weight percent on the oxide basis of SiO 2 --56-59 Al 2 O 3 --16-17 B 2 O 3 --4.5-5.25 CaO--7.5-9.25 MgO--5.5-6.25 BaO--5-9
Inventors
- 👤 William H. Dumbaugh, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:08
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/089; C03C3/091; C03C3/093
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
111 words
A glass exhibiting a strain point in excess of 665° C., a liquidus temperature no higher than 1125° C., a viscosity at the liquidus of at least 50,000 poises, and a coefficient of thermal expansion (0°-300° C.) between about 42-46×10 -7 /°C., said glass consisting essentially, expressed in terms of weight percent on the oxide basis, of SiO 2 --56-59 Al 2 O 3 --16-17 B 2 O 3 --4.5-5.25 CaO--7.5-9.25 MgO--5.5-6.25 BaO--5-9 wherein the sum SiO 2 +Al 2 O 3 will not exceed about 75%, the weight ratio SiO 2 :Al 2 O 3 is maintained between about 3.1-3.7, and the weight ratio CaO:MgO is held between about 1.2-2.0.
Claim 2
Dependent Claim
111 words
A glass exhibiting a strain point in excess of 665° C., a liquidus temperature no higher than 1125° C., a viscosity at the liquidus of at least 50,000 poises, and a coefficient of thermal expansion (0°-300° C.) between about 42-46×10 -7 /°C., said glass consisting essentially, expressed in terms of weight percent on the oxide basis, of SiO 2 --56-59 Al 2 O 3 --16-17 B 2 O 3 --4.5-5.25 CaO--7.5-9.25 MgO--5.5-6.25 BaO--5-9 wherein the sum SiO 2 +Al 2 O 3 will not exceed about 75%, the weight ratio SiO 2 :Al 2 O 3 is maintained between about 3.1-3.7, and the weight ratio CaO:MgO is held between about 1.2-2.0.
Claim 3
Dependent Claim
12 words
A glass according to claim 1 also containing up to 3% SrO.
Claim 4
Dependent Claim
111 words
A glass exhibiting a strain point in excess of 665° C., a liquidus temperature no higher than 1125° C., a viscosity at the liquidus of at least 50,000 poises, and a coefficient of thermal expansion (0°-300° C.) between about 42-46×10 -7 /°C., said glass consisting essentially, expressed in weight percent on the oxide basis, of SiO 2 --54-59 Al 2 O 3 --15.5-17.5 B 2 O 3 --3.75-5.5 CaO--6-9.25 MgO--4-6.25 BaO--5-11 ZnO--up to 4 wherein the sum SiO 2 +Al 2 O 3 will not exceed about 75%, the weight ratio SiO 2 :Al 2 O 3 is maintained about 3.1-3.7, and the weight ratio CaO:MgO is held between about 1.2-2.0.
Claim 5
Dependent Claim
111 words
A glass exhibiting a strain point in excess of 665° C., a liquidus temperature no higher than 1125° C., a viscosity at the liquidus of at least 50,000 poises, and a coefficient of thermal expansion (0°-300° C.) between about 42-46×10 -7 /°C., said glass consisting essentially, expressed in weight percent on the oxide basis, of SiO 2 --54-59 Al 2 O 3 --15.5-17.5 B 2 O 3 --3.75-5.5 CaO--6-9.25 MgO--4-6.25 BaO--5-11 ZnO--up to 4 wherein the sum SiO 2 +Al 2 O 3 will not exceed about 75%, the weight ratio SiO 2 :Al 2 O 3 is maintained about 3.1-3.7, and the weight ratio CaO:MgO is held between about 1.2-2.0.
Claim 6
Dependent Claim
12 words
A glass according to claim 3 also containing up to 3% SrO.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1986-10-10 | 1987-04-11 | 1987-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-10 | 1991-04-11 | 1991-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-10 | 1995-04-11 | 1995-10-11 | $7700.00 | Window Closed / Lapsed |