Patent US3686474A successfully refreshed from Google Patents.
US3686474A
Expired / Lapsed
US
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Vacuum pumps
Assignee: BOC Group Ltd
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Filing: 1970-05-21
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Granted: 1972-08-22
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Expires: 1990-05-21
Abstract
Abstract A vapor vacuum pump includes an electrical vaporiser unit made of thin filaments of electroconductive material arranged to convey between them by capillary action the working liquid of the pump, for vaporization by heat generated by resistance of the filaments to passage of a current of electricity passing therethrough.
Inventors
- 👤 Basil Dixon Power
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:07
CPC Classifications
F; F04; F04F; F04F9/00; H; H05; H05B; H05B3/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
57 words
A vapor vacuum pump including an electrically heated vaporizer positioned remotely from a reservoir of working liquid and adapted to be supplied with the liquid under pressure, in which the vaporizer includes a bundle of thin filaments which are electro-conductive so that the bundle can vaporize liquid by Joule heat released over a very large surface area.
Claim 2
Dependent Claim
57 words
A vapor vacuum pump including an electrically heated vaporizer positioned remotely from a reservoir of working liquid and adapted to be supplied with the liquid under pressure, in which the vaporizer includes a bundle of thin filaments which are electro-conductive so that the bundle can vaporize liquid by Joule heat released over a very large surface area.
Claim 3
Dependent Claim
56 words
A vapor vacuum pump as claimed in claim 1 in which the filaments are compacted to define interstitial spaces therebetween and so that said interstitial spaces are longitudinally extending and are of size small enough for the liquid to be vaporized to be drawn into the interior of the vaporizer at least partially by capillary forces.
Claim 4
Dependent Claim
23 words
A vapor vacuum pump as claimed in claim 2, in which the vaporizer includes separate and contiguous layers of conductive and non-conductive filaments.
Claim 5
Dependent Claim
21 words
A vapor vacuum pump as claimed in claim 3, in which the layers of filaments are circular or annular in cross-section.
Claim 6
Dependent Claim
21 words
A vapor vacuum pump as claimed in claim 3, in which the cross-sectional area of the bundle varies along its length.
Claim 7
Dependent Claim
26 words
A vapor vacuum pump as claimed in claim 1, in which the bundle has a hollow core into which is introduced the liquid to be vaporized.
Claim 8
Dependent Claim
60 words
A vapor vacuum pump as claimed in claim 1, in which the bundle of filaments is positioned in a helical groove in the surface of a support of insulation material, the bundle being in communication at a plurality of points spaced along its length with a hollow passage in the interior of the support for the liquid to be vaporized.
Claim 9
Dependent Claim
38 words
A vapor vacuum pump as claimed in claim 1, in which the bundle of filaments is positioned in a housing having an inlet for liquid at one end, and having an outlet for vapor at its other end.
References Cited (Backward Citations)
US3344257A
Cited
CA814547A
Cited
US2140516A
Cited
GB496788A
Cited
US2501276A
Cited
US3346718A
Cited
US3344979A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |