US4056378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for preparation of VO2 current inrush limiters for incandescent lamps
Assignee: Philips North America LLC
•
Filing: 1976-09-15
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Granted: 1977-11-01
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Expires: 1996-09-15
Abstract
Abstract Current inrush limiter for incandescent lamps is made by mixing finely divided vanadium sesquioxide and vanadium pentoxide with finely divided glass-forming constituents which include vanadium compound. The mix is compacted and sintered in a substantially inert atmosphere which converts the vanadium oxides to vanadium dioxide maintained in a chemically stable and mechanically strong mass by vitreous binder.
Inventors
- 👤 James P. McHugh
- 👤 Philip J. Nalepa
- 👤 Robert C. Miller
- 👤 Chester W. Dawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:23
CPC Classifications
H; H01; H01K; H01K1/00; H01K1/62; H05; H05B; H05B39/00; H05B39/02
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
172 words
The method of making a current inrush limiter for incandescent lamps substantially comprising vanadium dioxide particles maintained in a chemically stable and mechanically strong mass of predetermined dimensions by a glassy matrix binder, which method comprises: a. mixing together finely divided vanadium sesquioxide and vanadium pentoxide wherein the molar ratio of said finely divided vanadium sesquioxide to said finely divided vanadium pentoxide is from 1:1 to 2:1 together with finely divided glass-forming constituents which include at least one of vanadium oxide and metallic vanadate, with the weight ratio of said total finely divided vanadium sesquioxide plus vanadium pentoxide to said total glass-forming constituents being from 98:2 to 70:30; b. compacting said mixture into the shape desired for said limiter; c. sintering said compact in a substantially inert atmosphere at a temperature of from about 800° C to about 1100° C for a sufficient period of time to react and convert the mixed vanadium sesquioxide and vanadium pentoxide particles to vanadium oxide and to form said glass-forming constituents into said glassy matrix binder.
Claim 2
Independent Claim
172 words
The method of making a current inrush limiter for incandescent lamps substantially comprising vanadium dioxide particles maintained in a chemically stable and mechanically strong mass of predetermined dimensions by a glassy matrix binder, which method comprises: a. mixing together finely divided vanadium sesquioxide and vanadium pentoxide wherein the molar ratio of said finely divided vanadium sesquioxide to said finely divided vanadium pentoxide is from 1:1 to 2:1 together with finely divided glass-forming constituents which include at least one of vanadium oxide and metallic vanadate, with the weight ratio of said total finely divided vanadium sesquioxide plus vanadium pentoxide to said total glass-forming constituents being from 98:2 to 70:30; b. compacting said mixture into the shape desired for said limiter; c. sintering said compact in a substantially inert atmosphere at a temperature of from about 800° C to about 1100° C for a sufficient period of time to react and convert the mixed vanadium sesquioxide and vanadium pentoxide particles to vanadium oxide and to form said glass-forming constituents into said glassy matrix binder.
Claim 3
Dependent Claim
31 words
The method of claim 1, wherein said glass-forming constituents have the composition (P 2 O 5 ) 1 .2 . (BaO) 0 .4 . (V 2 O 5 ) 0 .6.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein a dopant for said vanadium dioxide is included in said mixture.
Claim 5
Dependent Claim
34 words
The method of claim 3, wherein there is included with said substantially inert atmosphere in which said compact is sintered a partial pressure of oxygen of from about 10 -3 to 10 -8 atmosphere.
Claim 6
Dependent Claim
13 words
The method of claim 4, wherein said substantially inert atmosphere principally comprises nitrogen.
Claim 7
Dependent Claim
44 words
The method of claim 5, wherein said finely divided vanadium sesquioxide is about 50 weight percent of said mixture, said finely divided vanadium pentoxide is about 31 weight percent of said mixture, and the glass-forming constituents are about 19 weight percent of said mixture.
Claim 8
Dependent Claim
17 words
The method of claim 6, wherein said mixture includes 0.05 weight percent of an organic pressing lubricant.
Claim 9
Dependent Claim
36 words
The method of claim 7, wherein prior to said sintering, said compact is baked in an oxidizing atmosphere at a temperature sufficient to volatilize said organic lubricant but substantially below the melting temperature for vanadium pentoxide.
Claim 10
Dependent Claim
12 words
The method of claim 8, wherein said organic lubricant is polyethylene glycol.
Claim 11
Dependent Claim
22 words
The method of claim 6, wherein said dopant is MoO 3 having a concentration of about 0.03 weight percent of said mixture.
Claim 12
Dependent Claim
24 words
The method of claim 8, wherein said baking of said compact is conducted at a temperature of about 300° C for about one hour.
Claim 13
Dependent Claim
23 words
The method of claim 11, wherein said sintering of said compact is conducted at a temperature of 1000° C for about 24 minutes.
Claim 14
Dependent Claim
24 words
The method of claim 5, wherein said finely divided vanadium sesquioxide and said finely divided vanadium pentoxide are mixed together in about equimolar ratio.
Claim 15
Dependent Claim
14 words
The method of claim 13, wherein said glass-forming constituents are about 17.5 weight percent.
Claim 16
Dependent Claim
22 words
The method of claim 14, wherein said dopant is MoO 3 having a concentration of 0.05 weight percent of said vanadium pentoxide.
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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) | 1980-10-31 | 1981-05-02 | 1981-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-31 | 1985-05-02 | 1985-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-31 | 1989-05-02 | 1989-11-01 | $7700.00 | Window Closed / Lapsed |