Patent US3711237A successfully refreshed from Google Patents.
US3711237A
Expired / Lapsed
US
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Ignition and control devices for fuel burners
Assignee: MBK Industrie SA
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Filing: 1971-08-02
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Granted: 1973-01-16
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Expires: 1991-08-02
Abstract
Abstract The subject matter of the disclosure relates to a control device which is an improvement on French Pat. No. 1,598,786 wherein the ignition and detection of the presence or absence of a flame are both effected at a relatively low frequency (less than 1 Hz) whereas according to the improvement, means are provided to effect the ignition at a relatively higher frequency and the detection at a relatively low frequency. Additional safety means may be included.
Inventors
- 👤 E Jaulmes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:44
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/02; F23N5/12; F23N5/123; F23Q; F23Q3/00; F23Q3/004; F02; F02P; F02P17/00; F02P17/12; F02P2017/125; F02P2017/126; F23N2227/00; F23N2227/36; F23N2231/00; F23N2231/04; F23N2239/00; F23N2239/06
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
122 words
An ignition and safety device for burners consuming hydrocarbon fuels or other combustible fluid fuels, comprising: a single electrode for igniting the fuel positioned to form a spark gap between itself and the burner; pulse-generating means operable to deliver to the electrode a succession of sparkproducing pulse trains, the pulse trains being separated from one another by intervals which are longer than the duration of each train; detector means for detecting the presence of absence of a flame when a spark occurs across the said gap; and means whereby when ignition takes place the pulse-generating means changes over automatically to cause the production of sparks at a frequency substantially lower than the frequency of the pulses in the said first mentioned trains.
Claim 2
Dependent Claim
122 words
An ignition and safety device for burners consuming hydrocarbon fuels or other combustible fluid fuels, comprising: a single electrode for igniting the fuel positioned to form a spark gap between itself and the burner; pulse-generating means operable to deliver to the electrode a succession of sparkproducing pulse trains, the pulse trains being separated from one another by intervals which are longer than the duration of each train; detector means for detecting the presence of absence of a flame when a spark occurs across the said gap; and means whereby when ignition takes place the pulse-generating means changes over automatically to cause the production of sparks at a frequency substantially lower than the frequency of the pulses in the said first mentioned trains.
Claim 3
Dependent Claim
45 words
A device in accordance with claim 1, in which the frequency of the pulses in the said pulse trains is that of the main supply, and in which the frequency of the sparks produced once ignition has taken place is not greater than 1 Hz.
Claim 4
Dependent Claim
59 words
A device in accordance with claim 2 in which the detector means includes means responsive to the extinction of the flame to cause a number of attempts to re-ignite the flame by sparks at the said lower frequency and, if this is unsuccessful, to cause the application to the electrode of a number of the said high-frequency pulse trains.
Claim 5
Dependent Claim
47 words
A device in accordance with claim 3 in which the detector means includes means responsive to a predetermined number of the said pulse trains without ignition taking place to close and block a fuel valve in such a manner that manual intervention is required to reopen it.
Claim 6
Dependent Claim
22 words
A device in accordance with claim 3 for igniting light hydrocarbons, in which the ignition means are of the capacitive discharge type.
Claim 7
Dependent Claim
21 words
A device in accordance with claim 3 for igniting heavy hydrocarbons, in which the ignition means are of the inductive type.
Claim 8
Dependent Claim
41 words
A device in accordance with claim 1 including a pressure-controlled device responsive to a failure of the fuel supply to cut the electrical supply to the circuit and operative to re-establish the electrical supply automatically when the fuel supply is re-established.
Claim 9
Dependent Claim
42 words
A device in accordance with claim 3 in which the detector means includes means responsive to a short-circuit condition between the electrode and the burner to close a fUel valve in such a manner that manual intervention is required to re-open it.
Claim 10
Dependent Claim
38 words
A device in accordance with claim 3 in which the detector means includes means responsive to an abnormally high burner temperature to close a fuel valve in such a manner that manual intervention is required to open it.
Claim 11
Dependent Claim
41 words
A device in accordance with claim 1 for controlling temperature in heat exchanges, in which the temperature control is maintained by successive ignition and extinction periods, the device including a relaxation oscillator controlled by variations in the resistance of a thermistor.
Claim 12
Dependent Claim
35 words
A device in accordance with claim 1 in which the pulses of the said higher frequency are interrupted to form pulse trains by a relay operated by pulses produced in the absence of a flame.
Claim 13
Dependent Claim
47 words
A device in accordance with claim 1 in which the individual sparks in the said trains of sparks are generated at the frequency of the alternating current supply by means of a circuit including a threshold diode connected in series with the gate of a discharge thyristor.
Claim 14
Dependent Claim
58 words
A device in accordance with claim 1 in which the pulses for producing the sparks at the said lower frequency are obtained by means of two series-connected capacitors connected in a charging circuit and a transistor arranged to short-circuit one of the said capacitors when it is driven into conduction by the periodic charging of a further capacitor.
Claim 15
Dependent Claim
49 words
A device in accordance with claim 6, including a power transistor connected to interrupt the current flowing through the primary coil of an ignition transformer and thereby to produce an inductive spark having a duration of at least 1,500 microseconds, the power transistor being biased by a monostable circuit.
Claim 16
Dependent Claim
56 words
A device in accordance with claim 4 including means to count the attempts to re-ignite the fuel comprising an integrating capacitor which is charged, one step at a time, with each train of pulses, and a transistor operative when this capacitor is charged to its threshold level to energize a relay which closes a fuel valve.
Claim 17
Dependent Claim
73 words
A device in accordance with claim 7 including a circuit having a capacitor which is charged over a resistor, the capacitor being partially discharged with each low-frequency detection spark when the burner is functioning normally, and a transistor responsive to the charge on the said capacitor and operable when the detection spark fails to take place or when there is a short circuit in the electrode circuit, to close the said fuel valve.
Claim 18
Dependent Claim
73 words
A device in accordance with claim 8 including a circuit having a capacitor which is charged over a resistor, the capacitor being partially discharged with each low-frequency detection spark when the burner is functioning normally, and a transistor responsive to the charge on the said capacitor and operable when the detection spark fails to take place or when there is a short circuit in the electrode circuit, to close the said fuel valve.
Claim 19
Dependent Claim
64 words
A device in accordance with claim 10 including means for detecting an abnormal increase in the burner temperature comprising a resistance having a positive temperature coefficient, in a resistance-capacitance circuit such that in the case of an abnormal increase in temperature the voltage across a capacitance fails to reach the threshold of a transistor to the control electrode of which the capacitor is connected.
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) | 1976-01-16 | 1976-07-17 | 1977-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-16 | 1980-07-17 | 1981-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-16 | 1984-07-17 | 1985-01-16 | $7700.00 | Window Closed / Lapsed |