US4436831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Calcined member for arc-extinguishing chambers
Assignee: Mitsubishi Electric Corp
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Filing: 1982-07-15
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Granted: 1984-03-13
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Expires: 2002-07-15
Abstract
Abstract A calcined member for arc-extinguishing chambers which are installed in electromagnetic contactors and magnetic circuit breakers for high-voltage applications. The calcined member consists of an inorganic composite material obtained by molding and heat-treating a starting material under pressurized condition, the starting material comprising 10 to 50% by weight of a mica powder as a base material, 10 to 50% by weight of a magnesium oxide as a charging material, and 25 to 60% by weight of a mixture powder of boric acid, boric anhydride and zinc oxide as a binder.
Inventors
- 👤 Shizutaka Nishizako
- 👤 Isao Ishii
- 👤 Yoshiaki Sakamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:41
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/02; H01B3/04; C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; H01H; H01H9/00; H01H9/30; H01H9/34; Y; Y10; Y10S; Y10S106/00; Y10S106/03
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
98 words
A calcined member for arc-extinguishing chambers, which consists of an inorganic composite insulation material obtained by molding and heat-treating a starting material under pressurized condition, said starting material consisting essentially of 10 to 50% by weight of a mica powder as a base material, 10 to 50% by weight of a magnesium oxide as a charging material, and 25 to 60% by weight of a binder of boric acid, boric anhydride and zinc oxide, the boric acid being present in an amount of 20 to 60 parts by weight based on 100 total parts by weight of binder.
Claim 2
Dependent Claim
98 words
A calcined member for arc-extinguishing chambers, which consists of an inorganic composite insulation material obtained by molding and heat-treating a starting material under pressurized condition, said starting material consisting essentially of 10 to 50% by weight of a mica powder as a base material, 10 to 50% by weight of a magnesium oxide as a charging material, and 25 to 60% by weight of a binder of boric acid, boric anhydride and zinc oxide, the boric acid being present in an amount of 20 to 60 parts by weight based on 100 total parts by weight of binder.
Claim 3
Dependent Claim
23 words
A calcined member for arc-extinguishing chambers according to claim 1, wherein the amount of mica powder ranges from 20 to 40% by weight.
Claim 4
Dependent Claim
24 words
A calcined member for arc-extinguishing chambers according to claim 2, wherein the amount of magnesium oxide powder ranges from 20 to 40% by weight.
Claim 5
Dependent Claim
20 words
A calcined member for arc-extinguishing chambers according to claim 3, wherein the binder ranges from 30 to 50% by weight.
Claim 6
Dependent Claim
37 words
A calcined member for arc-extinguishing chambers according to claim 4, wherein the binder consists of 20 to 60 parts of boric acid, 5 to 30 parts of boric anhydride, and 30 to 60 parts of zinc oxide.
Claim 7
Dependent Claim
37 words
A calcined member for arc-extinguishing chambers according to claim 5, wherein the binder consists of 30 to 50 parts of boric acid, 10 to 25 parts of boric anhydride, and 35 to 50 parts of zinc oxide.
Claim 8
Dependent Claim
23 words
A calcined member for arc-extinguishing chambers according to claim 1, wherein the molding is effected at a temperature of 170° to 180° C.
Claim 9
Dependent Claim
26 words
A calcined member for arc-extinguishing chambers according to claim 7, wherein the molding is effected under the pressurized condition of 150 to 200 kg/cm 2 .
Claim 10
Dependent Claim
33 words
A calcined member for arc-extinguishing chambers according to claim 1, wherein the mica powder which serves as a base material is at least one selected from natural phlogopite, natural muscovite and synthetic mica.
Claim 11
Dependent Claim
38 words
A calcined member for arc-extinguishing chambers according to claim 1, wherein the powder of magnesium oxide which serves as the charging material is at least one selected from electrofused magnesium oxide, sintered magnesium oxide and baked magnesium oxide.
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) | 1987-03-13 | 1987-09-12 | 1988-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-13 | 1991-09-12 | 1992-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-13 | 1995-09-12 | 1996-03-13 | $7700.00 | Window Closed / Lapsed |