US3720798A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum-type current interrupter
Assignee: Nissin Electric Co Ltd
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Filing: 1970-09-03
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Granted: 1973-03-13
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Expires: 1990-09-03
Abstract
Abstract Vacuum-type current interrupter having a shield surrounding the contacts so as to block and condense the metallic vapor generated by arcing between the contacts upon separation thereof. The shield is made of partially sintered metallic material to increase the effective surface area to catch and condense the metallic vapor and may be provided on the inner surface thereof with a plurality of generally radially inwardly projecting integral fins to further increase the inner working surface area thereof.
Inventors
- 👤 S Kabayama
- 👤 M Kume
- 👤 M Isei
- 👤 A Katou
- 👤 S Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:29
CPC Classifications
H; H01; H01H; H01H33/00; H01H33/60; H01H33/66; H01H33/662; H01H33/66261; H01H2033/66269
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
107 words
In a vacuum-type current interrupter, an electrically insulative housing adapted to have a vacuum generated therein, a pair of separable contacts disposed within the housing, and means defining a shield which is disposed in the housing so as to surround the contacts and contain the metallic vapor which is generated by arcing between the contacts when they separate in use, the inner peripheral surface portion of which shield, around the perimeter thereof, consists essentially of a metal particulate material which is sintered to a rugged, mechanically strong condition in which the surface thereof has a multitude of microscopic recesses for receiving and condensing the metallic vapor therein.
Claim 2
Dependent Claim
107 words
In a vacuum-type current interrupter, an electrically insulative housing adapted to have a vacuum generated therein, a pair of separable contacts disposed within the housing, and means defining a shield which is disposed in the housing so as to surround the contacts and contain the metallic vapor which is generated by arcing between the contacts when they separate in use, the inner peripheral surface portion of which shield, around the perimeter thereof, consists essentially of a metal particulate material which is sintered to a rugged, mechanically strong condition in which the surface thereof has a multitude of microscopic recesses for receiving and condensing the metallic vapor therein.
Claim 3
Dependent Claim
19 words
The vacuum-type current interrupter according to claim 1 wherein the shield consists essentially of the sintered metal particulate material.
Claim 4
Dependent Claim
33 words
The vacuum-type current interrupter according to claim 1 wherein the metal particulate material is iron, cobalt, nickel, copper, silver, aluminum, tungsten, molybdenum, or a compound metal thereof, or stainless steel, bronze, or brass.
Claim 5
Dependent Claim
34 words
The vacuum-type current interrupter according to claim 1 wherein the inner peripheral surface portion of the shield also comprises about 0.5 - 4.0 percent by weight of a binder for the metal particulate material.
Claim 6
Dependent Claim
23 words
The vacuum-type current interrupter according to claim 1 wherein the metal particulate material is of about 20 - 325 mesh in particle size.
Claim 7
Dependent Claim
20 words
The vacuum-type current interrupter according to claim 5 wherein the particles are a mixture of relatively large and small particles.
Claim 8
Dependent Claim
44 words
The vacuum-type current interrupter according to claim 1 wherein the inner peripheral surface of the shield has one or more inwardly projecting fins thereon, which are integral with the surface portion of the shield and likewise consist essentially of the sintered metal particulate material.
Claim 9
Dependent Claim
23 words
The vacuum-type current interrupter according to claim 1 wherein the shield is interposed between the contacts and the housing, in spaced relationship thereto.
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) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |