US3704980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heating system
Assignee: TDK Micronas GmbH
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Filing: 1971-03-25
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Granted: 1972-12-05
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Expires: 1991-03-25
Abstract
Abstract A heating system including a spark ignitor for a pilot burner which utilizes a safety shut off valve operated by the pilot thermocouple when the pilot goes out, wherein the ignitor is connected in parallel with the thermostat. If an air or gas disturbance causes the pilot to go out, the same disturbance or a temporary electric power failure may prevent or delay pilot reignition. If the safety valve closed before reignition, no hazard exists. However, if the safety valve is still open while initially no reignition occurs, the thermostat opens the main valve and reignition is thus prevented for a relatively long time, e.g., several seconds, a large amount of gas can be dumped into the combustion chamber, mixed with air therein and exploded by delayed ignition. In the unique hook-up where the ignitor is connected in parallel with the thermostat, no delayed ignition can take place. If the pilot has not been reignited prior to the thermostat switch closing, i.e., calling for heat, the ignitor will be disabled by the thermostat switch thus preventing ignition.
Inventors
- 👤 Hendricus Johannes Lokkart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:55
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/02; F23N5/10; F23N5/105; F23N2227/00; F23N2227/36
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
402 words
A heating system comprising: an inlet; a main burner; an electromagnetic safety valve having an inlet and an outlet; a main solenoid valve, saiD safety valve and said main valve being connected in that order to said main burner to admit gas to said main burner only when both of said valves are open; a pilot burner connected from the outlet of said safety valve to receive combustible fuel therefrom when said safety valve is open; a thermocouple positioned adjacent said pilot burner to be heated when fuel escaping from said pilot burner is ignited; means electrically connecting said thermocouple to said safety valve, said thermocouple supplying an operating voltage to said safety valve sufficient to hold said safety valve open when the fuel escaping from said pilot burner is ignited for a sufficient length of time, said safety valve being adapted to close at a time after the pilot light has gone out; an electrical ignitor having ignition means connected to the output thereof and extending contiguous to said pilot burner for ignition of fuel escaping therefrom, said ignitor having first and second leads; first and second main leads; and a thermostat positioned in a space to be heated by said main burner and including a series circuit, said circuit including a series connected switch, said thermostat including a temperature sensitive device to close said switch when the ambient temperature falls below a set temperature and to open said switch when the ambient rises thereabove, said circuit having first and second leads connected from each end thereof, said first main lead being connected to said first circuit lead and to said first ignitor lead, said main valve including a solenoid winding having a lead connected from each end thereof, said second circuit lead being connected to said second ignitor lead and to one of said winding leads, said second main lead being connected to the other of said winding leads, said circuit having a resistance such that closure of said switch renders said ignitor inoperative, said ignitor being operative when said switch is open, said ignitor having an input resistance sufficiently large to prevent sufficient energization of said solenoid winding to open said main valve when said switch is open, the resistance of the parallel connection of said circuit and the ignitor input when said switch is closed to cause sufficient energization of said solenoid winding to open said main valve.
Claim 2
Dependent Claim
402 words
A heating system comprising: an inlet; a main burner; an electromagnetic safety valve having an inlet and an outlet; a main solenoid valve, saiD safety valve and said main valve being connected in that order to said main burner to admit gas to said main burner only when both of said valves are open; a pilot burner connected from the outlet of said safety valve to receive combustible fuel therefrom when said safety valve is open; a thermocouple positioned adjacent said pilot burner to be heated when fuel escaping from said pilot burner is ignited; means electrically connecting said thermocouple to said safety valve, said thermocouple supplying an operating voltage to said safety valve sufficient to hold said safety valve open when the fuel escaping from said pilot burner is ignited for a sufficient length of time, said safety valve being adapted to close at a time after the pilot light has gone out; an electrical ignitor having ignition means connected to the output thereof and extending contiguous to said pilot burner for ignition of fuel escaping therefrom, said ignitor having first and second leads; first and second main leads; and a thermostat positioned in a space to be heated by said main burner and including a series circuit, said circuit including a series connected switch, said thermostat including a temperature sensitive device to close said switch when the ambient temperature falls below a set temperature and to open said switch when the ambient rises thereabove, said circuit having first and second leads connected from each end thereof, said first main lead being connected to said first circuit lead and to said first ignitor lead, said main valve including a solenoid winding having a lead connected from each end thereof, said second circuit lead being connected to said second ignitor lead and to one of said winding leads, said second main lead being connected to the other of said winding leads, said circuit having a resistance such that closure of said switch renders said ignitor inoperative, said ignitor being operative when said switch is open, said ignitor having an input resistance sufficiently large to prevent sufficient energization of said solenoid winding to open said main valve when said switch is open, the resistance of the parallel connection of said circuit and the ignitor input when said switch is closed to cause sufficient energization of said solenoid winding to open said main valve.
Claim 3
Dependent Claim
42 words
The invention as defined in claim 1, wherein said ignitor is a spark ignitor which produces a spark at said pilot burner with a predetermined frequency when the pilot light is out, said ignition means including at least two spaced spark electrodes.
Claim 4
Dependent Claim
35 words
The invention as defined in claim 2, wherein said circuit includes a heat anticipator, said heat anticipator being a resistive heater positioned to heat said temperature sensitive device and connected in series with said switch.
Claim 5
Dependent Claim
40 words
The invention as defined in claim 3, including a conduit connecting the outlet of said safety valve with said pilot burner, and a manually operable valve connecting the outlet of said safety valve with the inlet of said main valve.
Claim 6
Dependent Claim
35 words
The invention as defined in claim 1, wherein said circuit includes a heat anticipator, said heat anticipator being a resistive heater positioned to heat said temperature sensitive device and connected in series with said switch.
References Cited (Backward Citations)
US3108630A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |