Patent US3579168A successfully refreshed from Google Patents.
US3579168A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cyclic switch
Assignee: National Aeronautics and Space Administration
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Filing: 1969-12-31
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Granted: 1971-05-18
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Expires: 1989-12-31
Abstract
Abstract A switch utilizing a liquid metal in the cavity of a metal chamber connected in a conductor through which current flows from a DC source to a load or vice versa. Abrupt, cyclic decreases in current are effected by the formation of vapor films or vapor cavities which form at the interfaces between the liquid metal and the walls of the chamber due to ohmic heating. A source of pressurized gas communicates with the interior of the chamber. Cooling means for the chamber are provided to extract heat at a predetermined rate. The chamber may also be subjected to ultrasonic waves and heat waves to alter the wetting-dewetting action of the liquid metal.
Inventors
- 👤 Alex Vary
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:59
CPC Classifications
H; H01; H01H; H01H29/00; H01H29/006
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
67 words
A switch for cyclically varying current being supplied from a DC source to a load comprising: a condUctor connected between said DC source and said load; a metal chamber disposed in said conductor in electrical contact therewith; a liquid metal disposed in said chamber, said liquid metal substantially filling said chamber; a source of pressurized gas communicating with said chamber; and means for cooling said liquid metal.
Claim 2
Dependent Claim
67 words
A switch for cyclically varying current being supplied from a DC source to a load comprising: a condUctor connected between said DC source and said load; a metal chamber disposed in said conductor in electrical contact therewith; a liquid metal disposed in said chamber, said liquid metal substantially filling said chamber; a source of pressurized gas communicating with said chamber; and means for cooling said liquid metal.
Claim 3
Dependent Claim
16 words
The switch of claim 1 and further including means for impressing ultrasonic waves on said chamber.
Claim 4
Dependent Claim
19 words
The switch of claim 1 and further including means for heating said chamber and said liquid metal contained therein.
Claim 5
Dependent Claim
21 words
The switch of claim 1 wherein said liquid metal is selected from the group consisting of mercury, sodium, potassium and lithium.
Claim 6
Dependent Claim
23 words
The switch of claim 1 wherein said chamber has at least two oppositely facing flat sides contacting respective end faces of a bus-bar.
Claim 7
Dependent Claim
35 words
The switch of claim 5 wherein said cooling means comprises passageways formed in said bus-bar adjacent to at least one of said flat sides of said chamber, a cooling medium being disposed in said passageways.
Claim 8
Dependent Claim
23 words
The switch of claim 5 wherein said flat sides of said chamber are silver brazed to said respective end faces of said bus-bar.
Claim 9
Dependent Claim
43 words
The switch of claim 1 wherein said conductor is a bifurcated bus-bar and said chamber is V-shaped having a pair of upper surfaces contacting respective faces of a wedge-shaped bus-bar, each of the bifurcations contacting a respective lower surface of said V-shaped chamber.
Claim 10
Dependent Claim
30 words
The switch of claim 8 wherein said cooling means comprise a passageway formed in each bifurcation adjacent to said lower surfaces of said chamber, each passageway containing a cooling medium.
Claim 11
Dependent Claim
87 words
A switch for interrupting current flowing from a DC source to a load comprising: a metal housing; a metal conduit extending through said housing, electrical conductor means connecting said DC source, said load, said housing and said conduit; a heat-absorbing medium disposed in said conduit; electrical insulating means disposed between said housing and said conduit; a liquid metal substantially filling said housing; and a source of pressurized gas communicating with said housing, said DC source and said load being serially connected between said housing and said conduit.
Claim 12
Dependent Claim
87 words
A switch for interrupting current flowing from a DC source to a load comprising: a metal housing; a metal conduit extending through said housing, electrical conductor means connecting said DC source, said load, said housing and said conduit; a heat-absorbing medium disposed in said conduit; electrical insulating means disposed between said housing and said conduit; a liquid metal substantially filling said housing; and a source of pressurized gas communicating with said housing, said DC source and said load being serially connected between said housing and said conduit.
Claim 13
Dependent Claim
16 words
The switch of claim 10 and further including means for impressing ultrasonic waves on said housing.
Claim 14
Dependent Claim
19 words
The switch of claim 10 and further including means for heating said housing and said liquid metal contained therein.
Claim 15
Dependent Claim
20 words
The switch of claim 10 wherein said gas is selected from the group consisting of xenon, argon, neon and nitrogen.
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) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |