US4658324A
Expired / Lapsed
US
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Surge absorbing device
Assignee: Okaya Electric Industry Co Ltd
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Filing: 1985-06-28
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Granted: 1987-04-14
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Expires: 2005-06-28
Abstract
Abstract A surge absorbing device of composite construction comprising a high resistance element of metal oxide and a pair of electrodes connected to the high resistance element with a discharging gap formed between the electrodes. At a normal state, a fine current flows through the high resistance element, but when a surge voltage is transiently applied across the high resistance element, a triggering discharge is produced across the electrodes by a voltage drop of the product of the resistance value of the high resistance element and the value of surge current whereby it is immediately transferred to a main discharge of large current to absorb the surge current at a high velocity. A heat-proof and reduction-proof protective film is formed on the surface of the high resistance element to stabilize the characteristic of surge absorption. The protective film may be formed of a carbide of a carbon group element, of lead borosilicate glass or deleaded glass, or of a multi-layer of lead borosilicate glass or deleaded glass and metal oxide.
Inventors
- 👤 Toshikazu Inaba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:42
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10; H01C7/12
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
71 words
A surge absorbing device comprising a high resistance element of metal oxide having a surface, a pair of electrodes provided on the surface of said high resistance element and facing each other with a discharge gap formed between said electrodes, a hermetically sealed case in which said high resistance element and said electrodes are contained, and a heat-proof and reduction-proof protective film formed on the surface of said high resistance element.
Claim 2
Dependent Claim
71 words
A surge absorbing device comprising a high resistance element of metal oxide having a surface, a pair of electrodes provided on the surface of said high resistance element and facing each other with a discharge gap formed between said electrodes, a hermetically sealed case in which said high resistance element and said electrodes are contained, and a heat-proof and reduction-proof protective film formed on the surface of said high resistance element.
Claim 3
Dependent Claim
24 words
A surge absorbing device as set forth in claim 1, wherein said protective film is formed of a carbide of a carbon group element.
Claim 4
Dependent Claim
17 words
A surge absorbing device as set forth in claim 2, wherein said carbon group element is silicon.
Claim 5
Dependent Claim
19 words
A surge absorbing device as set forth in claim 2, wherein said protective film has a partially discontinuous construction.
Claim 6
Dependent Claim
20 words
A surge absorbing device as set forth in claim 1, wherein said protective film is formed of lead borosilicate glass.
Claim 7
Dependent Claim
19 words
A surge absorbing device as set forth in claim 5, wherein said lead borosilicate glass has a crystallized construction.
Claim 8
Dependent Claim
40 words
A surge absorbing device as set forth in claim 1 wherein said protective film comprises a multi-layer of an outer layer portion of deleaded glass and an inner layer portion of metal oxide chemically nonreactive with said outer layer portion.
Claim 9
Dependent Claim
24 words
A surge absorbing device as set forth in claim 7, wherein said outer layer portion of said protective film is formed of bismuth glass.
Claim 10
Dependent Claim
40 words
A surge absorbing device as set forth in claim 7, wherein said inner layer portion of said protective film is formed of at least one member selected from the group of magnesium oxide, silicon oxide, tin oxide and aluminum oxide.
Claim 11
Dependent Claim
20 words
A surge absorbing device as set forth in claim 1, wherein said high resistance element has a voltage nonlinear characteristic.
Claim 12
Dependent Claim
20 words
A surge absorbing device as set forth in claim 1, wherein said high resistance element has a voltage linear characteristic.
Claim 13
Dependent Claim
29 words
A surge absorbing device as set forth in claim 1, wherein said high resistance element has a portion of voltage nonlinear characteristic and another portion of voltage linear characteristic.
Claim 14
Dependent Claim
20 words
A surge absorbing device as set forth in claim 1, wherein said hermetically sealed case is filled with gaseous medium
Claim 15
Dependent Claim
27 words
A surge absorbing device as set forth in claim 13, wherein said gaseous medium is selected from the group of noble gas, nitrogen gas and carbon dioxide.
Claim 16
Dependent Claim
25 words
A surge absorbing device as set forth in claim 14, wherein said gaseous medium includes at least one of oxygen gas and an oxygen compound.
Claim 17
Dependent Claim
18 words
A surge absorbing device as set forth in claim 1, wherein said hermetically sealed case is substantially evacuated.
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) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |