US3921985A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contactless flow-guidance system
Assignee: Individual
•
Filing: 1974-01-04
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Granted: 1975-11-25
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Expires: 1994-01-04
Abstract
Abstract A flow of hot gases, e.g. in a mixing tube of a jet engine or in a cylinder of an internal-combustion engine, is kept out of contact with a confining surface by an electron-emissive coating on that surface held at a negative potential, the work function of the coating being lowered by the heat of the gases and/or by other heating means. The system can be used to minimize frictional resistance between the gas and a tube wall, or to block gas leakage between a cylinder and its piston.
Inventors
- 👤 Hans Fimml
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:21
CPC Classifications
F; F01; F01D; F01D11/00; F02; F02K; F02K1/00; F02K1/78; F02K1/82; F02K7/00; F02K7/10; F02K7/12; F15; F15D; F15D1/00; F15D1/02; Y; Y02; Y02T; Y02T50/00; Y02T50/60; Y10; Y10S; Y10S277/00; Y10S277/919; Y10S277/93
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
102 words
A contactless seal between a Piston member and a cylinder member having confronting surfaces closely spaced from each other by a narrow peripheral gap, said cylinder member forming a chamber for a fluid to be confined, said seal comprising a thermionic coating on the confronting surface of one of said members, heating means for raising the temperature of said coating to an electron-emissive level, and biasing means for maintaining the region of said gap at a potential more negative than that of a part of said chamber remote from said gap for repelling said fluid upon ionization thereof by the emitted electrons.
Claim 2
Dependent Claim
102 words
A contactless seal between a Piston member and a cylinder member having confronting surfaces closely spaced from each other by a narrow peripheral gap, said cylinder member forming a chamber for a fluid to be confined, said seal comprising a thermionic coating on the confronting surface of one of said members, heating means for raising the temperature of said coating to an electron-emissive level, and biasing means for maintaining the region of said gap at a potential more negative than that of a part of said chamber remote from said gap for repelling said fluid upon ionization thereof by the emitted electrons.
Claim 3
Dependent Claim
31 words
A seal as defined in claim 1 wherein said piston and cylinder members form part of an internal-combustion engine, said chamber being a combustion chamber forming part of said heating means.
Claim 4
Dependent Claim
29 words
A contactless seal as defined in claim 1 wherein said heating means comprises an electric resistance element carried on said one of said members adjacent said confronting surface thereof.
Claim 5
Dependent Claim
31 words
A contactless seal as defined in claim 3 wherein said one of said members is provided with a refractory layer adjacent said coating, said resistance element being imbedded in said layer.
Claim 6
Dependent Claim
40 words
A contactless seal as defined in claim 1 wherein one of said confronting surfaces is provided with an annular zone negatively biased with reference to said remote part to form a potential barrier downstream of said coating within said gap.
Claim 7
Dependent Claim
35 words
A contactless seal as defined in claim 5 wherein said coating is carried on said piston member, said annular zone being constituted by a peripheral rib of said piston member spaced from said cylinder member.
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) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |