Patent US3934451A successfully refreshed from Google Patents.
US3934451A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of detecting imperfections in a heat-insulating lining
Assignee: Shell USA Inc
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Filing: 1973-05-29
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Granted: 1976-01-27
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Expires: 1993-05-29
Abstract
Abstract A method of detecting imperfections in a heat-insulating lining of foamed material of the wall of a space suitable for cryogenic uses by cooling the surfaces of the lining by scanning with a jet of cooled gas and observing the lining for imperfections in the cooled state.
Inventors
- 👤 Paul Bristoll
- 👤 Godefridus Arink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:42
CPC Classifications
F; F17; F17C; F17C13/00; F17C13/12; F17C13/126; G; G01; G01N; G01N25/00; G01N25/72; F17C2203/00; F17C2203/03; F17C2221/00; F17C2221/03; F17C2221/032; F17C2221/033; F17C2223/00; F17C2223/01; F17C2223/0146; F17C2223/0153; F17C2223/0161; F17C2260/00; F17C2260/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
48 words
A method of detecting imperfections in a heat-insulating lining of foamed material of a wall enclosing a space suitable for cryogenic uses, comprising locally cooling the surface of the lining by scanning with a jet of cooled gas and observing the lining for imperfections in the cooled state.
Claim 2
Independent Claim
48 words
A method of detecting imperfections in a heat-insulating lining of foamed material of a wall enclosing a space suitable for cryogenic uses, comprising locally cooling the surface of the lining by scanning with a jet of cooled gas and observing the lining for imperfections in the cooled state.
Claim 3
Dependent Claim
13 words
The method of claim 1 comprising utilizing vapors of liquid nitrogen for cooling.
Claim 4
Dependent Claim
16 words
The method of claim 1 including photographing the imperfections in the cooled state for marking purposes.
Claim 5
Dependent Claim
17 words
The method of claim 1 including marking the imperfection while it remains visible in the cooled state.
Claim 6
Independent Claim
73 words
A method for detecting a crack or split in a foamed lining on the inner surface of a wall of a tank utilized for transporting a cold liquid comprising temporarily and locally cooling the surface of the foamed lining with a jet of cooled gas in order to cause the surface to contract and thereby render the crack or split visible without magnification and marking the crack or split while it remains visible.
Claim 7
Independent Claim
73 words
A method for detecting a crack or split in a foamed lining on the inner surface of a wall of a tank utilized for transporting a cold liquid comprising temporarily and locally cooling the surface of the foamed lining with a jet of cooled gas in order to cause the surface to contract and thereby render the crack or split visible without magnification and marking the crack or split while it remains visible.
Claim 8
Independent Claim
66 words
A method for detecting a crack or split in a foamed plastic material in which the crack or split enlarges upon cooling of the material by subjecting the material to temporary and local cooling whereby the crack or split becomes visible as the plastic material shrinks and the crack or split widens, and marking the crack or split while the plastic is in the cooled state.
Claim 9
Independent Claim
66 words
A method for detecting a crack or split in a foamed plastic material in which the crack or split enlarges upon cooling of the material by subjecting the material to temporary and local cooling whereby the crack or split becomes visible as the plastic material shrinks and the crack or split widens, and marking the crack or split while the plastic is in the cooled state.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-26 | 1979-07-28 | 1980-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-26 | 1983-07-28 | 1984-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-26 | 1987-07-28 | 1988-01-27 | $7700.00 | Window Closed / Lapsed |