US3764764A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum circuit breaker
Assignee: Hitachi Ltd
•
Filing: 1971-01-11
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Granted: 1973-10-09
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Expires: 1991-01-11
Abstract
Abstract In a vacuum circuit breaker having at least a pair of electrodes which generate an arc when detached from each other in a high vacuum tank, said electrodes are made of a copper alloy containing a low-melting-point substance and opposing contact surfaces each in the shape of a ring are placed along the periphery of the electrodes. The electrodes have about two to four grooves extending from the peripheral edge of the contact surfaces to the internal surfaces of the electrodes which are maintained detached from each other, whereby current paths in the electrodes are formed almost in parallel with the contact surfaces of the electrodes over a certain length from an arcing point in the peripheral direction at the time of ignition, thus self-driving the arc in the peripheral direction. The electrodes have on the back side thereof reinforcing materials which are mechanically strong enough to make up for the lack of the mechanical strength required for the electrodes and which are sufficiently low in electric conductivity compared with the electrode materials to such a degree so as not to allow the intensity of the magnetic field to drop to a point lower than a level required by the electrodes.
Inventors
- 👤 Y Kurosawa
- 👤 T Takasuna
- 👤 H Sugawara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:17
CPC Classifications
H; H01; H01H; H01H33/00; H01H33/60; H01H33/66; H01H33/664; H01H33/6643; H01H33/6644
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
153 words
A vacuum circuit breaker having at least a pair of electrodes which are detachable from each other to generate an arc, said electrodes comprising holding members and electrode members respectively, said electrode members including: ring-shaped opposing contact surfaces formed at the respective ends of said holding members, thereby being capable of contacting each other; opposing internal surfaces formed at the inside of said respective opposing contact surfaces and untouchably facing each other, the inner diameters of said opposing contact surfaces being larger than the outer diameters of said holding portions, respectively; and current-limiting regions extending from the outer peripheral edges of said contact surfaces to the inside of said opposing internal surfaces, respectively, thereby forming currents paths substantially in parallel with the contact surfaces of said electrodes over a prescribed length from an arcing point in the peripheral direction at the time of ignition, whereby the arc is self-driven in the peripheral direction.
Claim 2
Dependent Claim
153 words
A vacuum circuit breaker having at least a pair of electrodes which are detachable from each other to generate an arc, said electrodes comprising holding members and electrode members respectively, said electrode members including: ring-shaped opposing contact surfaces formed at the respective ends of said holding members, thereby being capable of contacting each other; opposing internal surfaces formed at the inside of said respective opposing contact surfaces and untouchably facing each other, the inner diameters of said opposing contact surfaces being larger than the outer diameters of said holding portions, respectively; and current-limiting regions extending from the outer peripheral edges of said contact surfaces to the inside of said opposing internal surfaces, respectively, thereby forming currents paths substantially in parallel with the contact surfaces of said electrodes over a prescribed length from an arcing point in the peripheral direction at the time of ignition, whereby the arc is self-driven in the peripheral direction.
Claim 3
Dependent Claim
25 words
A vacuum circuit breaker according to claim 1, in which said current-limiting regions are provided in the number of two to four per one electrode.
Claim 4
Dependent Claim
22 words
A vacuum circuit breaker according to claim 1, in which said current-limiting regions are formed by grooves in materials constituting the electrodes.
Claim 5
Dependent Claim
90 words
A vacuum circuit breaker according to claim 1, in which opposing contact surfaces are made of a material containing a low-melting-point substance, said electrode members having on the respective back sides thereof reinforcing members which are strong enough to make up for the want of the mechanical strength required of the electrodes and which are sufficiently low in electric conductivity compared with the electrode members to such a degree as not to reduce the intensity of a megnetic field to a point lower than a level required of the electrodes.
Claim 6
Dependent Claim
44 words
A vacuum circuit breaker according to claim 4, in which each of said reinforcing members has a corresponding current-limiting region along the current-limiting region provided on the electrode members, thereby preventing a current from advancing straight in the radial direction in the reinforcing members.
Claim 7
Dependent Claim
48 words
A vacuum circuit breaker according to claim 4, in which each of the electrode members has a ring-shaped recess on the back side thereof along the ring-shaped contact surface, thereby narrowing the distance between the parallel current paths formed in the opposing electrodes at the time of ignition.
Claim 8
Dependent Claim
230 words
A vacuum circuit breaker having at least a pair of electrodes which are detachable in such a manner as to generate an arc in a high vacuum tank, each of said electrodes comprising: a holder for supporting the electRode; a disc-shaped member including an electrode member electrically connected to said holder, the outer diameter of said electrode member being larger than the outer diameter of said holder, and a reinforcing member formed on the back side of said electrode member for mechanically reinforcing said electrode; and a cylinder-shaped member fixed on said disc-shaped member, the inner diameter of said cylinder-shaped member being larger than the outer diameter of said holder, said cylinder-shaped member including conductor members which are electrically connected with said electrode member respectively and overlapped equally one on another sandwiching current-limiting regions therebetween respectively to form a cylinder-shaped assembly, and arc electrode members made of a substance with a low melting point provided on the upper surface of said cylinder-shaped assembly, each of said arc electrode members being fixed to said respective conductor members and being separated from the next by a current limiting groove, thereby forming current paths substantially in parallel with the contact surfaces of the electrodes over a prescribed length from an arcing point in the peripheral direction inside the electrodes at the time of ignition, whereby the arc is self-driven in the peripheral direction.
Claim 9
Dependent Claim
230 words
A vacuum circuit breaker having at least a pair of electrodes which are detachable in such a manner as to generate an arc in a high vacuum tank, each of said electrodes comprising: a holder for supporting the electRode; a disc-shaped member including an electrode member electrically connected to said holder, the outer diameter of said electrode member being larger than the outer diameter of said holder, and a reinforcing member formed on the back side of said electrode member for mechanically reinforcing said electrode; and a cylinder-shaped member fixed on said disc-shaped member, the inner diameter of said cylinder-shaped member being larger than the outer diameter of said holder, said cylinder-shaped member including conductor members which are electrically connected with said electrode member respectively and overlapped equally one on another sandwiching current-limiting regions therebetween respectively to form a cylinder-shaped assembly, and arc electrode members made of a substance with a low melting point provided on the upper surface of said cylinder-shaped assembly, each of said arc electrode members being fixed to said respective conductor members and being separated from the next by a current limiting groove, thereby forming current paths substantially in parallel with the contact surfaces of the electrodes over a prescribed length from an arcing point in the peripheral direction inside the electrodes at the time of ignition, whereby the arc is self-driven in the peripheral direction.
Claim 10
Dependent Claim
72 words
A vacuum circuit breaker according to claim 7, in which said reinforcing materials and said current-limiting regions are mechanically strong enough to make up for the want of the mechanical strength required by the electrodes and have sufficiently low electric conductivity compared with the electrode members to such a degree so as not to reduce the intensity of a magnetic field to a point lower than a level required of the electrodes.
Claim 11
Dependent Claim
173 words
A vacuum circuit breaker having a pair of electrodes which are detachable from each other for generating an arc therebetween, said electrodes comprising holding members and electrode members, respectively, said electrode members including: annular opposing contact surface portions formed at the respective ends of said holding members, so as to be capable of contacting each other, the inner diameter of said opposing contact surface portions being larger than the outer diameters of said holding portions, respectively; opposing internal surface portions spaced apart from and facing one another formed in the interior of said opposing contact surface portions and circumferentially surrounded by said annular contact surfaces; and means for forming current paths substantially in parallel with the contact surfaces of said contact surface portions of said electrodes over a prescribed length from the point of arcing in the peripheral direction upon ignition, including current-limiting regions extending from the outer peripheral edges of said contact surfaces to the interior of said opposing internal surface portions, respectively, whereby the arc is self-driven in the peripheral direction.
Claim 12
Dependent Claim
173 words
A vacuum circuit breaker having a pair of electrodes which are detachable from each other for generating an arc therebetween, said electrodes comprising holding members and electrode members, respectively, said electrode members including: annular opposing contact surface portions formed at the respective ends of said holding members, so as to be capable of contacting each other, the inner diameter of said opposing contact surface portions being larger than the outer diameters of said holding portions, respectively; opposing internal surface portions spaced apart from and facing one another formed in the interior of said opposing contact surface portions and circumferentially surrounded by said annular contact surfaces; and means for forming current paths substantially in parallel with the contact surfaces of said contact surface portions of said electrodes over a prescribed length from the point of arcing in the peripheral direction upon ignition, including current-limiting regions extending from the outer peripheral edges of said contact surfaces to the interior of said opposing internal surface portions, respectively, whereby the arc is self-driven in the peripheral direction.
Claim 13
Dependent Claim
75 words
A vacuum circuit breaker according to claim 9, in which said opposing contact surface portions are made of a material containing a low-melting-point substance, said electrode members having reinforcing members on the respective back portions thereof for supplying mechanical strength to the electrodes and having a significantly lower electrical conductivity compared with the electrode members, for preventing reduction of the intensity of said magnetic field to a level lower than that required of the electrodes.
Claim 14
Dependent Claim
48 words
A vacuum circuit breaker according to claim 10, in which each of the electrode members has a ring-shaped recess on the back side thereof along the ring-shaped contact surface, thereby narrowing the distance between the parallel current paths formed in the opposing electrodes at the time of ignition.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |