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US3889079A
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Vacuum-type circuit interrupters having an axial magnetic field produced by condensing shield coils
Assignee: Westinghouse Electric Corp
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Filing: 1973-09-14
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Granted: 1975-06-10
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Expires: 1993-09-14
Abstract
Abstract A vacuum-type circuit interrupter is provided having an axial magnetic field provided therein through the use of currents transmitted to the surrounding shield structure, the latter being electrically connected by means of a field coil to one of the separable contacts. In one embodiment, the surrounding condensing shield is connected by an internal coil strap to one of the separable contacts. In another embodiment, the coil, providing the axial magnetic field, is disposed externally of the evacuated envelope, and is connected by a connection extending through the envelope to the condensing shield, which may be electrically isolated internally from the electrodes or contacts. In another embodiment, the axial magnetic field-producing coil is disposed externally of the envelope, but has a connection to an end plate, which, additionally, is electrically connected to the internal condensing shield. Another embodiment has the condensing shield provided in the form of a helical conducting strap. In another embodiment, a split condensing shield is connected by strapcoil connecters to both of the separable contacts of the vacuum interrupter for creating an axial magnetic field. In another embodiment, the ''''floating'''' shield has a generally spiral configuration adjacent to the arcing gap. The ''''floating'''' shield will draw net electron current on the cathode side of the shield, and a compensating ion current on the anode side. The resulting circulating current will cause an axial magnetic field to be set up interiorly of the vacuum interrupter. In yet another embodiment of the invention the condensing shield is connected by a field coil to one of the fixed electrodes of a fixed-gap vacuum device to assist in extinguishing the arc established between the two fixed electrodes.
Inventors
- 👤 Werner S Emmerich
- 👤 Clive W Kimblin
- 👤 Richard L Hundstad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:28
CPC Classifications
H; H01; H01H; H01H33/00; H01H33/60; H01H33/66; H01H33/664; H01H33/662; H01H33/66261; H01H2033/66269; H01H2033/66292
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
149 words
A circuit-interrupting device of the vacuum type comprising, in combination: a. means defining a highly-evacuated envelope including an insulating casing; b. a pair of electrodes disposed within said highly-evacuated envelope and having a fixed gap therebetween at least in the fully-open position of said interrupting device; c. means for at times establishing an arc across said gap between the two electrodes; d. metallic condensing-shielding means disposed interiorly of said highly-evacuated envelope for preventing deposition of metallic vapor from the arcing region onto the inner walls of said insulating casing for preventing flashover across the insulating casing; e. magnetic field-producing means for developing across said gap an axial magnetic field that has its lines of force extending across said gap generally parallel to the longitudinal axis of said arc; and, f. said magnetic field-producing means including a field-coil electrically interconnecting said metallic condensing shielding means to one of said electrodes.
Claim 2
Dependent Claim
149 words
A circuit-interrupting device of the vacuum type comprising, in combination: a. means defining a highly-evacuated envelope including an insulating casing; b. a pair of electrodes disposed within said highly-evacuated envelope and having a fixed gap therebetween at least in the fully-open position of said interrupting device; c. means for at times establishing an arc across said gap between the two electrodes; d. metallic condensing-shielding means disposed interiorly of said highly-evacuated envelope for preventing deposition of metallic vapor from the arcing region onto the inner walls of said insulating casing for preventing flashover across the insulating casing; e. magnetic field-producing means for developing across said gap an axial magnetic field that has its lines of force extending across said gap generally parallel to the longitudinal axis of said arc; and, f. said magnetic field-producing means including a field-coil electrically interconnecting said metallic condensing shielding means to one of said electrodes.
Claim 3
Dependent Claim
27 words
The circuit-interrupting device of claim 1, wherein the pair of electrodes are constituted by a pair of separable contacts which make engagement and disengagement with each other.
Claim 4
Dependent Claim
26 words
The combination according to claim 1, wherein the metallic condensing-shielding means is generally cylindrical and the field coil is disposed within the cylindrically-shaped metallic condensing shield.
Claim 5
Dependent Claim
28 words
The combination according to claim 2, wherein the metallic condensing-shielding means is generally cylindrical and the magnetic field coil is disposed interiorly of the cylindrically-shaped metallic condensing shield.
Claim 6
Dependent Claim
23 words
The combination according to claim 2, wherein the field coil electrically interconnects the condensing shielding means to the stationary contact of the device.
Claim 7
Dependent Claim
24 words
The combination according to claim 2, wherein the field coil electrically interconnects the condensing shielding means with the movable contact of the interrupting device.
Claim 8
Dependent Claim
98 words
A vacuum-type alternating-current circuit interrupter including means defining an evacuated envelope having an insulating casing, separable contacts disposed within said evacuated envelope and separable from each other to establishing arcing between the separated contacts, condensing-shield means for preventing the deposition of metallic vapor from the region of arcing onto the inner wall of the insulating casing, and a conducting strap electrically interconnecting the condensing shield means with one of the separable contacts, whereby a magnetic field coil is thus provided to produce an axial magnetic field within the evacuated envelope and in the region of the arcing gap.
Claim 9
Dependent Claim
98 words
A vacuum-type alternating-current circuit interrupter including means defining an evacuated envelope having an insulating casing, separable contacts disposed within said evacuated envelope and separable from each other to establishing arcing between the separated contacts, condensing-shield means for preventing the deposition of metallic vapor from the region of arcing onto the inner wall of the insulating casing, and a conducting strap electrically interconnecting the condensing shield means with one of the separable contacts, whereby a magnetic field coil is thus provided to produce an axial magnetic field within the evacuated envelope and in the region of the arcing gap.
Claim 10
Dependent Claim
20 words
The combination according to claim 7, wherein the conducting strap is electrically connected to the stationary contact of the interrupter.
Claim 11
Dependent Claim
18 words
The combination according to claim 8, wherein the conducting strap is electrically connected to the stationary contact stem.
Claim 12
Dependent Claim
29 words
The combination according to claim 7, wherein a field-coil interconnects the condensing shield to one of the contacts and said field coil is disposed externally of the evacuated envelope.
Claim 13
Dependent Claim
25 words
The combination according to claim 10, wherein the support for the condensing shield constitutes a conductor electrically interconnecting the condensing shield with the externally-disposed field-coil.
Claim 14
Dependent Claim
67 words
The combination according to claim 7, wherein the evacuated envelope has a metallic end-plate and an insulating wall portion separates the end plate of the device and the stationary contact stem, and an externally-disposed field-coil surrounds said insulating portion and is electrically connected between the stationary contact stem and said end plate, and said condensing shield for the interrupter is electrically connected to said one end plate.
Claim 15
Dependent Claim
75 words
A vacuum-type circuit interrupter comprising means defining an evacuated envelope having a metallic end plate, a pair of separable contacts disposed interIorly within said evacuated envelope and separable to establish arcing, a condensing-shield means comprising a spiral strip of metal with the strips overlapping in order to protect the inner wall of the evacuated envelope from vapor deposition, and said spiral strap of metal being electrically connected to said one end plate of the interrupter.
Claim 16
Dependent Claim
75 words
A vacuum-type circuit interrupter comprising means defining an evacuated envelope having a metallic end plate, a pair of separable contacts disposed interIorly within said evacuated envelope and separable to establish arcing, a condensing-shield means comprising a spiral strip of metal with the strips overlapping in order to protect the inner wall of the evacuated envelope from vapor deposition, and said spiral strap of metal being electrically connected to said one end plate of the interrupter.
Claim 17
Dependent Claim
19 words
The combination according to claim 13, wherein said one end plate supports the stationary contact stem of the device.
Claim 18
Dependent Claim
26 words
The combination according to claim 13, wherein the spiral of the condensing-shield means are of increasing diameter in a direction away from said one end plate.
Claim 19
Dependent Claim
24 words
The combination according to claim 13, wherein said spiral strip is supported from said one end plate and is in good electrical contact therewith.
Claim 20
Dependent Claim
25 words
The combination according to claim 7, wherein the condensing shield is split and is electrically connected by two straps to both of the separable contacts.
Claim 21
Dependent Claim
29 words
The combination according to claim 7, wherein the condensing shield is electrically floating and comprises a pair of end loops with a coil electrically interconnecting the two end loops.
References Cited (Backward Citations)
US3702911A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |