Patent US4135538A successfully refreshed from Google Patents.
US4135538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermocouple protecting tube
Assignee: Koransha Co Ltd
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Filing: 1977-09-07
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Granted: 1979-01-23
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Expires: 1997-09-07
Abstract
Abstract The thermocouple protecting tube of this invention is characterized by having a heat-insulating layer in an annular space formed by and between an inner ceramic tube and an outer silica glass tube which are concentrically disposed within each other. Due to the above construction, the protecting tube can withstand the thermal shock which it receives when immersed in a molten body of high temperature and accordingly the thermocouple enclosed in the protecting tube can continuously measure the temperature of molten steel for a considerable length of time.
Inventors
- 👤 Sumihiko Kurita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:06
CPC Classifications
G; G01; G01K; G01K1/00; G01K1/08; G01K1/12; G01K1/125
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
66 words
A thermocouple protecting tube for continuously measuring the temperature of molten steel comprising: (a) an inner ceramic tube having one end closed, and containing a thermocouple element therein, (b) an outer silica glass tube disposed concentrically over said inner ceramic tube and over said one closed end of said inner tube forming an annular space therebetween, and (c) an intermediate heat-insulating layer within said annular space.
Claim 2
Dependent Claim
66 words
A thermocouple protecting tube for continuously measuring the temperature of molten steel comprising: (a) an inner ceramic tube having one end closed, and containing a thermocouple element therein, (b) an outer silica glass tube disposed concentrically over said inner ceramic tube and over said one closed end of said inner tube forming an annular space therebetween, and (c) an intermediate heat-insulating layer within said annular space.
Claim 3
Dependent Claim
28 words
A thermocouple protecting tube according to claim 1, wherein said inner ceramic tube is made of metal oxide selected from the group consisting of alumina, beryllia and magnesia.
Claim 4
Dependent Claim
18 words
A thermocouple protecting tube according to claim 1, wherein said inner ceramic tube is made of metal carbide.
Claim 5
Dependent Claim
18 words
A thermocouple protecting tube according to claim 1, wherein said inner ceramic tube is made of ceramic carbide.
Claim 6
Dependent Claim
18 words
A thermocouple protecting tube according to claim 1, wherein said inner ceramic tube is made of metal nitride.
Claim 7
Dependent Claim
26 words
A thermocouple protecting tube according to claim 1, wherein said inner ceramic tube is made of a mixture of metal oxide, metal carbide and ceramic carbide.
Claim 8
Dependent Claim
38 words
A thermocouple protecting tube according to claim 6, wherein said misture is composed of chromium oxide in an amount of about 1 to 35% by weight and alumina in an amount of about 99 to 65% by weight.
Claim 9
Dependent Claim
24 words
A thermocouple protecting tube according to claim 1, wherein said intermediate heat-insulating layer is comprised of ceramic paper wound around said inner ceramic tube.
Claim 10
Dependent Claim
24 words
A thermocouple protecting tube according to claim 1, wherein said intermediate heat-insulating layer is comprised of ceramic fiber wound around said inner ceramic tube.
Claim 11
Dependent Claim
31 words
A thermocouple protecting tube according to claim 1, wherein said intermediate heat-insulating layer is comprised of alumina cement of uniform thickness coated onto the outer surface of said inner ceramic tube.
Claim 12
Dependent Claim
23 words
A thermocouple protecting tube according to claim 1, wherein said intermediate heat-insulating layer is comprised of alumina powder filled in said annular space.
Claim 13
Dependent Claim
48 words
A thermocouple protective tube according to claim 1, wherein said intermediate heat insulating layer covers the outside of said inner ceramic tube including the closed end thereof but does not completely fill the space between the closed end of said inner ceramic tube and said outer glass tube.
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) | 1982-01-22 | 1982-07-24 | 1983-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-22 | 1986-07-24 | 1987-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-22 | 1990-07-24 | 1991-01-23 | $7700.00 | Window Closed / Lapsed |