Patent US4242879A successfully refreshed from Google Patents.
US4242879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for a refrigerating apparatus operable electrically or by gas
Assignee: Electrolux AB
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Filing: 1979-06-18
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Granted: 1981-01-06
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Expires: 1999-06-18
Abstract
Abstract An absorption refrigeration system has an electric heater connectable to an electric power source, and a gas burner connectable to a gas supply. A voltage responsive circuit is connected to disable the gas burner circuit when the voltage of an electric supply means is above a determined level, and to disable the electric heating circuit and enable the gas heating burner when the voltage is below the determined value.
Inventors
- 👤 Peter E. Blomberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:33
CPC Classifications
F; F25; F25B; F25B49/00; F25B49/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
116 words
In a control system for an absorption refrigeration apparatus having an electric heating means, gas heating means, and a gas control means for controlling said gas burner means, said gas control means including an electric circuit for igniting and maintaining a flame in said burner means; the improvement wherein said control system further comprises an input for receiving electric supply current, a voltage-dependent switch circuit coupled to said electric heating means for applying electric current thereto from said input when a voltage at said input exceeds a given value, and means coupling the voltage-dependent switch circuit to said electric circuit for enabling said gas control means when voltage at said input is below said given value.
Claim 2
Dependent Claim
116 words
In a control system for an absorption refrigeration apparatus having an electric heating means, gas heating means, and a gas control means for controlling said gas burner means, said gas control means including an electric circuit for igniting and maintaining a flame in said burner means; the improvement wherein said control system further comprises an input for receiving electric supply current, a voltage-dependent switch circuit coupled to said electric heating means for applying electric current thereto from said input when a voltage at said input exceeds a given value, and means coupling the voltage-dependent switch circuit to said electric circuit for enabling said gas control means when voltage at said input is below said given value.
Claim 3
Dependent Claim
37 words
The control system of claim 1 wherein said electric circuit further includes a battery for operating said gas control means, said voltage-dependent switch circuit including a relay having contacts for connecting said battery to said electric circuit.
Claim 4
Dependent Claim
27 words
The control system of claim 2 further comprising a charger connected to said input for charging said battery in the presence of electric voltage at said input.
Claim 5
Dependent Claim
43 words
The control system of claim 1 comprising a relay having a coil connected in series with said electric heating means, said means coupling said voltage-dependent switch circuit to said electric circuit comprising contacts of said relay connected in series with said electric circuit.
Claim 6
Dependent Claim
52 words
The control system of claim 4 further comprising a safety system including a safety valve for shutting off supply of gas to said burner means, and a safety circuit responsive to heat of said burner means for controlling said valve, said relay having further contacts connected in series in said safety circuit.
References Cited (Backward Citations)
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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) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |