US3959549A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-layer insulation for deep-cooled cables
Assignee: Siemens AG
•
Filing: 1974-08-01
•
Granted: 1976-05-25
•
Expires: 1994-08-01
Abstract
Abstract A multi-layer insulation for deep-cooled cables utilizing insulating foils having a dielectric loss factor less than 5×10.sup. -5 in which a layer of a spun bonded paper of high density polyethylene fibers is placed between each two layers of insulating foil thereby providing sufficient elasticity even when the cable is cooled to a very low temperature to equalize expansion differences occurring in the cable.
Inventors
- 👤 Peter Penczynski
- 👤 Peter Jacobsen
- 👤 Gunther Matthaus
- 👤 Peter Massek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:24
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/12; H; H01; H01B; H01B7/00; H01B7/02; H01B7/0241; B32B27/32; H01B12/00; H01B12/14; B32B2262/00; B32B2262/02; B32B2262/0253; B32B2307/00; B32B2307/20; B32B2307/206; B32B2323/00; B32B2323/04; B32B2323/043; B32B2457/00; Y; Y02; Y02E; Y02E40/00; Y02E40/60; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/856; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T442/00; Y10T442/60; Y10T442/681
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
88 words
A multi-layer electrical insulation employing insulating foils having a dielectric loss factor smaller than 5 × 10 - 5 for use in deep-cooled cables such as superconducting three-phase cables in a coaxial conductor configuration, comprising: a. a plurality of layers of insulating foil selected from the group consisting of high density polyethylene, polypropylene and polytetraflourethylene having a dielectric loss factor smaller than 55 × 10 - 5 ; and b. layers of spun bonded paper of high density polyethylene fibers between each two layers of said insulating foil.
Claim 2
Dependent Claim
88 words
A multi-layer electrical insulation employing insulating foils having a dielectric loss factor smaller than 5 × 10 - 5 for use in deep-cooled cables such as superconducting three-phase cables in a coaxial conductor configuration, comprising: a. a plurality of layers of insulating foil selected from the group consisting of high density polyethylene, polypropylene and polytetraflourethylene having a dielectric loss factor smaller than 55 × 10 - 5 ; and b. layers of spun bonded paper of high density polyethylene fibers between each two layers of said insulating foil.
Claim 3
Dependent Claim
29 words
Multi-layer insulation according to claim 1 wherein the thickness of the layers of insulating foil is approximately equal to the thickness of the layers of spun bonded paper fabric.
Claim 4
Dependent Claim
15 words
Multi-layer insulation according to claim 1 wherein the insulating foil consists of high density polyethylene.
Claim 5
Dependent Claim
21 words
A multi-layer insulation according to claim 1 wherein the insulation is impregnated with a liquid helium coolant of the deep-cooled cable.
References Cited (Backward Citations)
US3393268A
Cited
US3376378A
Cited
US3598691A
Cited
FR1541728A
Cited
US3595982A
Cited
US3616123A
Cited
DE2014010A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-25 | 1979-11-24 | 1980-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-25 | 1983-11-24 | 1984-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-25 | 1987-11-24 | 1988-05-25 | $7700.00 | Window Closed / Lapsed |