US3662205A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical switch device having a fed liquid-metal cathode and partially intercepting anode
Assignee: Raytheon Co
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Filing: 1970-07-02
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Granted: 1972-05-09
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Expires: 1990-07-02
Abstract
Abstract The electrical switch device has an envelope in which is mounted a liquid-metal cathode, an anode, and a condenser. The cathode is capable of very high electron-to-atom emission ratio. A desirable value for the electron-to-atom emission ratio is on the order of 100 or more and is attainable by means of a cathode such as disclosed in U.S. Pat. No. 3,475,636. The condenser has a very much larger area than the exposed liquid metal area on the cathode, and it is kept at a low enough temperature to efficiently condense the liquid-metal vapor emitted by the cathode. With mercury used as the liquid metal, the condenser temperature is kept substantially below 0* C., preferably at about -35* C. which is just above the melting point of mercury. When arcing occurs from the liquid metal, a plasma jet of electrons, ions, and neutral particles is emitted from the arc spot. The anode is mounted between the cathode and the condenser, and it partially intercepts the plasma jet. The combination of the high electron-to-atom emission ratio of the cathode with the large, low-temperature condenser results in an equilibrium background pressure (i.e., pressure outside the plasma jet) of at least as low as 10 3 Torr during arcing, and lower than 10 4 Torr during non-arcing periods. These low pressures are obtained by maintaining the condenser in the range of low temperatures defined above. This low background pressure, in turn, permits the essentially unperturbed propagation of the plasma jet between the cathode and the surfaces upon which it impinges, i.e., condenser and anode. Such a discharge mode is commonly referred to as a ''''vacuum arc.'''' The fact that the plasma jet is emitted only during arcing, and that the pressure within the space surrounding this jet is kept low, results in the ability to hold off electric fields up to 50 kV per centimeter between anode and cathode immediately after cessation of arcing.
Inventors
- 👤 Kenneth T Lian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:35
CPC Classifications
H; H01; H01J; H01J13/00; H01J13/02; H01J13/04; H01J2893/00; H01J2893/0072; H01J2893/0088; H01J2893/0089
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
288 words
An electrical switch device, said electrical switch device comprising: a vessel; anode means within said vessel, cathode means within said vessel and condenser means having a condensation surface within said vessel; said cathode means having a high arc voltage material wall; means for feeding a low arc voltage metal in other than the solid state to a position adjacent said cathode wall so that liquid metal is on said wall; said condensation surface: (1) having a sufficiently large area with respect to the liquid metal area on said cathode means, and (2) being positioned with respect to said cathode means and anode means, and (3) said cathode means, said anode means and said condenser means being operated, for causing an electric discharge between said cathode means and said anode means wherein an arc spot is formed on the liquid metal on said cathode wall from whence is ejected a plasma cone containing electrons, ions and neutral particles issuing directly toward said condensation surface, and said condensation surface is maintained at a sufficiently low temperature to capture substantially all of the neutral particles and ions emitted from the arc spot to permit maintenance of the background pressure within said vessel during arcing sufficiently low that the atmosphere in said vessel does not substantially interfere with the plasma cone so that discharge in a vacuum arc mode is maintained; said anode means being positioned between said cathode means and said condensation surface in the path of said plasma cone and being formed of a plurality of panels edgewise directed toward said cathode means so as to minimally perturb the ions and neutral particles in the plasma cone and so as to electrically couple said anode means with the plasma cone.
Claim 2
Dependent Claim
288 words
An electrical switch device, said electrical switch device comprising: a vessel; anode means within said vessel, cathode means within said vessel and condenser means having a condensation surface within said vessel; said cathode means having a high arc voltage material wall; means for feeding a low arc voltage metal in other than the solid state to a position adjacent said cathode wall so that liquid metal is on said wall; said condensation surface: (1) having a sufficiently large area with respect to the liquid metal area on said cathode means, and (2) being positioned with respect to said cathode means and anode means, and (3) said cathode means, said anode means and said condenser means being operated, for causing an electric discharge between said cathode means and said anode means wherein an arc spot is formed on the liquid metal on said cathode wall from whence is ejected a plasma cone containing electrons, ions and neutral particles issuing directly toward said condensation surface, and said condensation surface is maintained at a sufficiently low temperature to capture substantially all of the neutral particles and ions emitted from the arc spot to permit maintenance of the background pressure within said vessel during arcing sufficiently low that the atmosphere in said vessel does not substantially interfere with the plasma cone so that discharge in a vacuum arc mode is maintained; said anode means being positioned between said cathode means and said condensation surface in the path of said plasma cone and being formed of a plurality of panels edgewise directed toward said cathode means so as to minimally perturb the ions and neutral particles in the plasma cone and so as to electrically couple said anode means with the plasma cone.
Claim 3
Dependent Claim
245 words
An electrical switch device comprising: a vessel; condenser means having a condensation surface within said vessel for condensing ions and neutral particles in said vessel to maintain a sufficiently low background pressure within said vessel during arcing that the atmosphere in said vessel does not substantially interfere with arcing so that a plasma cone is formed, so that electric arc discharge in a vacuum arc mode can be maintained, said condensation surface being positioned in the path of the plasma cone; cathode means within said vessel for carrying a low arc voltage metal in sufficiently small area to minimize evaporation of low arc voltage metal from said cathode means into the atmosphere within sAid vessel to permit said condensation means to maintain the background pressure within said vessel during arcing sufficiently low so that the plasma cone is an arc discharge in a vacuum arc mode; anode means within said vessel for interacting with said cathode means so that an electric arc discharge in a vacuum arc mode is maintained from the low arc voltage metal on said cathode means to said anode means, said anode means being formed of a plurality of panels in the path of the plasma cone edgewise directed toward said cathode means so as to minimally perturb the ions and neutral particles in the plasma cone in their flow toward said condensation surface, and so as to electrically couple said anode means with the plasma cone to extract electrons therefrom.
Claim 4
Dependent Claim
245 words
An electrical switch device comprising: a vessel; condenser means having a condensation surface within said vessel for condensing ions and neutral particles in said vessel to maintain a sufficiently low background pressure within said vessel during arcing that the atmosphere in said vessel does not substantially interfere with arcing so that a plasma cone is formed, so that electric arc discharge in a vacuum arc mode can be maintained, said condensation surface being positioned in the path of the plasma cone; cathode means within said vessel for carrying a low arc voltage metal in sufficiently small area to minimize evaporation of low arc voltage metal from said cathode means into the atmosphere within sAid vessel to permit said condensation means to maintain the background pressure within said vessel during arcing sufficiently low so that the plasma cone is an arc discharge in a vacuum arc mode; anode means within said vessel for interacting with said cathode means so that an electric arc discharge in a vacuum arc mode is maintained from the low arc voltage metal on said cathode means to said anode means, said anode means being formed of a plurality of panels in the path of the plasma cone edgewise directed toward said cathode means so as to minimally perturb the ions and neutral particles in the plasma cone in their flow toward said condensation surface, and so as to electrically couple said anode means with the plasma cone to extract electrons therefrom.
Claim 5
Dependent Claim
54 words
The electrical switch device of claim 2 wherein said low arc voltage metal is mercury and said condenser means is maintained below 273* K to maintain a pressure within said vessel outside of the plasma cone at least as low as 10 3 Torr during arcing and lower than 10 4 Torr during non-arcing.
Claim 6
Dependent Claim
56 words
The electrical switch device of claim 3 wherein said cathode means has a high arc voltage material wall and said switch device further includes: means for feeding the low arc voltage metal in other than the solid state to a position adjacent said wall of said cathode means so that liquid metal is on said wall.
Claim 7
Dependent Claim
35 words
The electrical switch device of claim 4 wherein at least one of said panels is in the form of a truncated hollow cone with its apex substantially on said high arc voltage cathode material wall.
Claim 8
Dependent Claim
39 words
The electrical switch device of claim 5 wherein said anode means has an annular body having an interior frusto-conical surface, said interior surface of said annular body having its apex substantially at said high arc voltage cathode material wall.
Claim 9
Dependent Claim
20 words
The electrical switch device of claim 6 wherein said panels extend inwardly from said annular surface on said anode body.
Claim 10
Dependent Claim
58 words
The electrical switch device of claim 7 wherein said panels include a hollow frusto cone having its apex substantially on said high arc voltage cathode material wall, said hollow cone being connected to said panels extending from said surface on said anode body so as to support said hollow cone interiorly of said surface on said anode body.
Claim 11
Dependent Claim
275 words
An electrical switch device, said electrical switch device comprising: a vessel; an anode within said vessel, a cathode within said vessel and a condenser having a condensing surface within said vessel; said cathode having a high arc voltage material wall, means for feeding mercury in other than a solid state to a position on said wall so that an electric discharge in the vacuum arc mode can take place between said anode and an arc spot on the mercury on said wall from whence is ejected directly toward said anode a plasma cone containing electrons, ions and neutral particles; said anode being positioned between said cathode and said condenser surface in the path of said plasma cone and being formed of a plurality of panels edgewise directed toward said cathode so as to minimally perturb the ions and neutral particles in the plasma cone and so as to electrically couple said anode with the plasma cone; and cooling means connected to said condenser for maintaining said condensing surface between 273* K and 238* K; said condensing surface having a sufficiently large area with respect to the mercury area on said cathode and being positioned with respect to said cathode and said anode structure and being maintained at a sufficiently low temperature to capture substantially all of the neutral particles and ions emitted from the arc spot to permit maintenance of the background pressure within said vessel during arcing outside of the plasma jet, at least as low as 10 3 Torr so that the arc occurs in the vacuum arc mode and the atmosphere in said vessel does not subsTantially interfere with the plasma cone.
Claim 12
Dependent Claim
275 words
An electrical switch device, said electrical switch device comprising: a vessel; an anode within said vessel, a cathode within said vessel and a condenser having a condensing surface within said vessel; said cathode having a high arc voltage material wall, means for feeding mercury in other than a solid state to a position on said wall so that an electric discharge in the vacuum arc mode can take place between said anode and an arc spot on the mercury on said wall from whence is ejected directly toward said anode a plasma cone containing electrons, ions and neutral particles; said anode being positioned between said cathode and said condenser surface in the path of said plasma cone and being formed of a plurality of panels edgewise directed toward said cathode so as to minimally perturb the ions and neutral particles in the plasma cone and so as to electrically couple said anode with the plasma cone; and cooling means connected to said condenser for maintaining said condensing surface between 273* K and 238* K; said condensing surface having a sufficiently large area with respect to the mercury area on said cathode and being positioned with respect to said cathode and said anode structure and being maintained at a sufficiently low temperature to capture substantially all of the neutral particles and ions emitted from the arc spot to permit maintenance of the background pressure within said vessel during arcing outside of the plasma jet, at least as low as 10 3 Torr so that the arc occurs in the vacuum arc mode and the atmosphere in said vessel does not subsTantially interfere with the plasma cone.
Claim 13
Dependent Claim
68 words
The switch device of claim 9 wherein said condenser has a sufficiently large condensing surface area with respect to the liquid metal area on said cathode and is maintained at least as low about about 273* K so that pressure within said vessel outside of said plasma jet is not higher than about 10 3 Torr during arcing and not higher than about 10 4 Torr during non-arcing.
Claim 14
Dependent Claim
32 words
The electrical switch device of claim 10 wherein said cathode is operated so that the ratio of electrons to atoms within said plasma cone is at least as high as about fifty.
Claim 15
Dependent Claim
44 words
The switching device of claim 9 wherein said panels on said anode comprise at least one truncated hollow cone with its apex substantially on said higher arc voltage cathode material wall and at least one width attached to and supporting said truncated hollow cone.
Claim 16
Dependent Claim
166 words
The process of switching an electric current comprising the steps of: maintaining a vessel in which is positioned a condenser surface of sufficient size to dominate the vapor equilibrium in said vessel at a reduced pressure by maintaining the condenser surface at a reduced temperature; feeding liquid metal to a cathode in the vessel for arcing; cooling the condenser surface a sufficient degree so that arcing which occurs between the cathode and an anode in the vessel is in a vacuum arc mode; discharging an arc between the anode and cathode which produces a plasma jet containing electrons, ions and atoms with the ratio of electrons to atoms being at least 30-1; and directing the plasma jet through the anode toward the condenser so that the anode partially intercepts the plasma jet so that the anode is directly electrically coupled with the plasma jet for electron flow from the plasma jet to the anode and the condenser surface receives substantially all the ions and neutral particles.
Claim 17
Dependent Claim
166 words
The process of switching an electric current comprising the steps of: maintaining a vessel in which is positioned a condenser surface of sufficient size to dominate the vapor equilibrium in said vessel at a reduced pressure by maintaining the condenser surface at a reduced temperature; feeding liquid metal to a cathode in the vessel for arcing; cooling the condenser surface a sufficient degree so that arcing which occurs between the cathode and an anode in the vessel is in a vacuum arc mode; discharging an arc between the anode and cathode which produces a plasma jet containing electrons, ions and atoms with the ratio of electrons to atoms being at least 30-1; and directing the plasma jet through the anode toward the condenser so that the anode partially intercepts the plasma jet so that the anode is directly electrically coupled with the plasma jet for electron flow from the plasma jet to the anode and the condenser surface receives substantially all the ions and neutral particles.
Claim 18
Dependent Claim
223 words
An electrical switch device comprising: a vessel; anode means within said vessel, cathode means within said vessel, condenser means having a condensation surface within said vessel, feed means for feeding a low arc voltage metal in other than the solid state to an accessible position on said cathode means; said anode means, said cathode means, and said condenser means being for causing an electric discharge between said cathode means and said anode means in a vacuum arc mode wherein an arc spot is formed on the low arc voltage metal on said cathode means from whence is ejected a conical plasma jet issuing directly toward said condensation surface, said plasma jet containing electrons, ions, and neutral particles, a plurality of panels on said anode means edgewise directed toward said cathode means and extending into the plasma jet to electrically couple said anode means with the electrons in the plasma jet, and said condensation surface is maintained by said condenser means at a sufficiently low temperature to capture substantially all of the neutral particles and ions emitted from the arc spot and passing past said anode to permit maintenance of the background pressure within said vessel during arcing sufficiently low that the atmosphere in said vessel does not substantially interfere with the plasma jet so that discharge in a vacuum arc mode is maintained.
Claim 19
Dependent Claim
223 words
An electrical switch device comprising: a vessel; anode means within said vessel, cathode means within said vessel, condenser means having a condensation surface within said vessel, feed means for feeding a low arc voltage metal in other than the solid state to an accessible position on said cathode means; said anode means, said cathode means, and said condenser means being for causing an electric discharge between said cathode means and said anode means in a vacuum arc mode wherein an arc spot is formed on the low arc voltage metal on said cathode means from whence is ejected a conical plasma jet issuing directly toward said condensation surface, said plasma jet containing electrons, ions, and neutral particles, a plurality of panels on said anode means edgewise directed toward said cathode means and extending into the plasma jet to electrically couple said anode means with the electrons in the plasma jet, and said condensation surface is maintained by said condenser means at a sufficiently low temperature to capture substantially all of the neutral particles and ions emitted from the arc spot and passing past said anode to permit maintenance of the background pressure within said vessel during arcing sufficiently low that the atmosphere in said vessel does not substantially interfere with the plasma jet so that discharge in a vacuum arc mode is maintained.
References Cited (Backward Citations)
US2205231A
Cited
US3475636A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |