US3801865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for supplying electric power to loads in hazardous atmospheres
Assignee: Victor Products Ltd
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Filing: 1972-11-09
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Granted: 1974-04-02
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Expires: 1992-11-09
Abstract
Abstract In a power supply system for use in hazardous conditions, such as in mines, an inverter housed within a flame-proof enclosure is connected to a d.c. supply line and generates an a.c. output around the lower end of the kiloHertz range, e.g. up to approximately 100 kHz. The output may be connected to a load, such as a fluorescent lamp, either directly, or through a connector comprising a transformer having separable primary and secondary windings, or via a control circuit which provides an intrinsically safe supply.
Inventors
- 👤 F Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:49
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
88 words
A power supply system for use in hazardous atmospheres comprising: a flame proof enclosure; at least one inverter means housed within said enclosure; a direct current power supply line outside said enclosure and arranged to feed DC power into said enclosure via flame proof means to said inverter means from which DC power said inverter means produces an alternating current output having a frequency from the lower end of the kiloHertz range up to approximately 100 KHz; and means for connecting said alternating current output to load means.
Claim 2
Dependent Claim
88 words
A power supply system for use in hazardous atmospheres comprising: a flame proof enclosure; at least one inverter means housed within said enclosure; a direct current power supply line outside said enclosure and arranged to feed DC power into said enclosure via flame proof means to said inverter means from which DC power said inverter means produces an alternating current output having a frequency from the lower end of the kiloHertz range up to approximately 100 KHz; and means for connecting said alternating current output to load means.
Claim 3
Dependent Claim
26 words
A system as claimed in claim 1, in which said inverter means comprises an oscillator and a power amplifier coupled to the output of the oscillator.
Claim 4
Dependent Claim
16 words
A system as claimed in claim 1, in which said inverter means comprises a power oscillator.
Claim 5
Dependent Claim
28 words
A system as clAimed in claim 1, in which the a.c. output is applied to output cable means which extends out of the enclosure in a flame-proof manner.
Claim 6
Dependent Claim
29 words
A system as claimed in claim 1, including a connector for connecting the a.c. output to a load, the connector comprising separable primary and secondary windings of a transformer.
Claim 7
Dependent Claim
21 words
A system as claimed in claim 5, in which the primary and secondary windings are respectively inside and outside the enclosure.
Claim 8
Dependent Claim
42 words
A system as claimed in claim 1, including a control circuit coupled to the invertor output and disposed within the enclosure, which control circuit is operative to provide at least one intrinsically safe supply for connection to a load outside the enclosure.
Claim 9
Dependent Claim
25 words
A system as claimed in claim 1, including a plurality of said inverter means mounted in separate enclosures and connected to a common d.c. line.
Claim 10
Dependent Claim
45 words
A system as claimed in claim 8, in which inverter means are connected to the d.c. line in a string, the line entering each enclosure in a flame-proof manner and emerging from the enclosure in a flame-proof manner for entry into the next successive enclosure.
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) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |