US3909676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-operating fault current limiter switch
Assignee: ABB Inc USA
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Filing: 1974-04-22
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Granted: 1975-09-30
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Expires: 1994-04-22
Abstract
Abstract A parallel-connected inductance and capacitor are connected in parallel with a normally closed switching device and in series with an electric power distribution system. The capacitive reactance of the capacitor is substantially higher than the inductive reactance of the inductor at the power line frequency. The normally closed switching device is opened in response to a predetermined level of fault current in the system so that the reactor is inserted into the power distribution system to effect limitation of current level. The switching device is springbiased to a closed position and the current path through the switch contacts forms a blow-open magnetic circuit, whereby the contacts are blown open against the closing force of the biasing springs when the predetermined current magnitude is reached. Means are provided to produce a high arcing voltage in a pressurized liquid medium.
Inventors
- 👤 Lorne D Mcconnell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:48
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/02; H01; H01H; H01H33/00; H01H33/02; H01H33/59; H01H33/60; H01H33/68; H01H77/00; H01H77/02; H01H77/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
230 words
A self-operating switching device comprising, in combination: first and second cooperable contact means; first and second terminals for said first and second contact means respectively; first and second conductors connecting said first and second terminals to said first and second contact means respectively; housing means for enclosing said first and second contact means and at least portions of said first and second conductors; said first and second terminals extending through the wall of said housing means; the interior volume of said housing means being filled with a dielectric fluid at least to a level which encloses said first and second cooperable contact means; at least one of said first and second cooperable contact means being movable relative to the other; biasing means connected to said one of said first and second contact means for biasing said first and second contact means to an engaged condition; said first and second contact means and said first and second conductors defining a bent current-carrying path which produces a blow-off force between said first and second cooperable contact means which tends to oppose the force of said biasing means, whereby said first and second contact means are opened when the current in said current-carrying path exceeds a given value; and delay means connected to at least saiD one of said contact means for delaying the reclosing of said contact means after the opening thereof.
Claim 2
Dependent Claim
230 words
A self-operating switching device comprising, in combination: first and second cooperable contact means; first and second terminals for said first and second contact means respectively; first and second conductors connecting said first and second terminals to said first and second contact means respectively; housing means for enclosing said first and second contact means and at least portions of said first and second conductors; said first and second terminals extending through the wall of said housing means; the interior volume of said housing means being filled with a dielectric fluid at least to a level which encloses said first and second cooperable contact means; at least one of said first and second cooperable contact means being movable relative to the other; biasing means connected to said one of said first and second contact means for biasing said first and second contact means to an engaged condition; said first and second contact means and said first and second conductors defining a bent current-carrying path which produces a blow-off force between said first and second cooperable contact means which tends to oppose the force of said biasing means, whereby said first and second contact means are opened when the current in said current-carrying path exceeds a given value; and delay means connected to at least saiD one of said contact means for delaying the reclosing of said contact means after the opening thereof.
Claim 3
Dependent Claim
14 words
The self-operating switch of claim 1 wherein said dielectric fluid is sulfur hexafluoride liquid.
Claim 4
Dependent Claim
44 words
The self-operating switch of claim 1 which includes arc runner means connected to said first and second contact means respectively and extending in generally parallel lines away from said contact means; said arc runner means being at least partly immersed in said dielectric fluid.
Claim 5
Dependent Claim
86 words
The self-operating switch of claim 1 wherein said first and second conductors are generally piston-shaped first and second members aligned and facing one another; said first and second contact means being respectively secured to the central face of said first and second piston-shaped members; said first piston-shaped member being axially movable under the magnetic blow-off force produced by the U-shaped current paths produced by said piston member to disengage said first and second contact means when said blow-off force exceeds the force of said biasing means.
Claim 6
Dependent Claim
14 words
The self-operating switch of claim 4 wherein said dielectric fluid is sulfur hexafluoride liquid.
Claim 7
Dependent Claim
36 words
The self-operating switch of claim 1 wherein said first contact means comprises a movable bridging contact and wherein said second contact means comprises a fixed pair of spaced contacts which are bridged by said bridging contact.
Claim 8
Dependent Claim
14 words
The self-operating switch of claim 6 wherein said dielectric fluid is sulfur hexafluoride liquid.
Claim 9
Dependent Claim
44 words
The self-operating switch of claim 7 which includes arc runner means connected to said first and second contact means respectively and extending in generally parallel lines away from said contact means; said arc runner means being at least partly immersed in said dielectric fluid.
Claim 10
Dependent Claim
22 words
The self-operating switch of claim 6 wherein said bridging contact is pivotally mounted on one of said fixed pair of spaced contacts.
Claim 11
Dependent Claim
19 words
The self-operating switch of claim 6 wherein said delay means includes a dashpot piston connected to said bridging contact.
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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |