Patent US4717333A successfully refreshed from Google Patents.
US4717333A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Burner ignition system
Assignee: Laars Inc
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Filing: 1986-01-17
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Granted: 1988-01-05
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Expires: 2006-01-17
Abstract
Abstract An electronic ignition system for a gas burner is battery operated. The battery voltage is applied through a DC-DC chopper to a step-up transformer to charge a capacitor which provides the ignition spark. The step-up transformer has a significant leakage reactance in order to limit current flow from the battery during initial charging of the capacitor. A tank circuit at the input of the transformer returns magnetizing current resulting from the leakage reactance to the primary in succeeding cycles. An SCR in the output circuit is gated through a voltage divider which senses current flow through a flame. Once the flame is sensed, further sparks are precluded. The same flame sensor enables a thermopile driven main valve actuating circuit. A safety valve in series with the main gas valve responds to a control pressure thermostatically applied through a diaphragm. The valve closes after a predetermined delay determined by a time delay orifice if the pilot gas is not ignited.
Inventors
- 👤 Forest J. Carignan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:20
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/20; F23N5/203; F23N5/02; F23N5/10; F23N5/102; F23Q; F23Q9/00; F23Q9/08; F23Q9/12; F23Q9/14; F23N2227/00; F23N2227/36; F23N2229/00; F23N2235/00; F23N2235/12; F23N2235/18; F23N2235/20; F23N2235/24; F23N5/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
126 words
A gas control in a gas burning system comprising a safety valve in series with a main gas valve and a pilot nozzle, the safety valve comprising a normally closed valve element for preventing gas flow to the main gas valve, a control chamber, means for increasing the pressure in the control chamber and valve control means responsive to increased pressure in the control chamber to open the valve element, the gas control further including a time delay orifice for venting the control chamber and flame responsive means for opening the main gas valve and terminating venting of the control chamber through the time delay orifice when a flame is sensed such that the safety valve closes after a predetermined delay if no flame is sensed.
Claim 2
Dependent Claim
126 words
A gas control in a gas burning system comprising a safety valve in series with a main gas valve and a pilot nozzle, the safety valve comprising a normally closed valve element for preventing gas flow to the main gas valve, a control chamber, means for increasing the pressure in the control chamber and valve control means responsive to increased pressure in the control chamber to open the valve element, the gas control further including a time delay orifice for venting the control chamber and flame responsive means for opening the main gas valve and terminating venting of the control chamber through the time delay orifice when a flame is sensed such that the safety valve closes after a predetermined delay if no flame is sensed.
Claim 3
Dependent Claim
73 words
A gas control as claimed in claim 1 further comprising an input chamber normally closed by the valve element, wherein the valve control means is driven by a pressure differential between the input chamber and the control chamber, the means for increasing the pressure in the control chamber comprising a diaphragm which has one face exposed to the control chamber and an opposite face exposed to line pressure through a thermostatically controlled valve.
Claim 4
Dependent Claim
26 words
A gas control as claimed in claim 1 wherein the safety valve, when opened, closes a switch which connects an electrical supply to an ignition circuit.
Claim 5
Dependent Claim
68 words
A gas control as claimed in claim 1 further comprising an input chamber connected to a supply of gas such that a line pressure is established therein and having an outpout normally closed by the valve element, wherein the valve control means is driven by a pressure differential between the input chamber and the control chamber across a diaphragm, and the valve element is actuated by the diaphragm.
Claim 6
Dependent Claim
38 words
A gas control as claimed in claim 4 wherein the output of the input chamber is coupled to an outlet chamber and the valve member is further coupled to a diaphragm between the outlet chamber and ambient pressure.
Claim 7
Dependent Claim
31 words
A gas control as claimed in claim 4 wherein the pressure in the control chamber is established through a diaphragm which is exposed to line pressure through as thermostatically controlled valve.
Claim 8
Dependent Claim
61 words
A gas control as claimed in claim 4 wherein the main gas valve is opened only when a pilot flame is sensed and the means for venting the gas which holds the valve open vents to a line between the main gas valve and a burner assembly such that the gas is not vented once the main gas valve is opened.
Claim 9
Dependent Claim
62 words
An gas control system as claimed in claim 1 wherein the main gas valve is open only when a pilot flame is sensed and the means for venting the gas which holds the valve open vents to a line between the main gas valve and a burner assembly such that the gas is not vented once the main gas valve is opened.
Claim 10
Dependent Claim
168 words
A gas control in a gas burning system comprising a safety valve in series with a main gas valve and with a pilot nozzle, the safety valve limiting the flow of gas to each of the main gas valve and the pilot nozzle and comprising: an input chamber for receiving gas; a normally closed valve element for preventing gas flow from the input chamber to the main gas valve and to the pilot nozzle; a control chamber; valve control means responsive to a pressure differential between the control chamber and the input chamber to open the valve element with increased pressure in the control chamber; a thermostatically controlled valve for increasing the pressure in the control chamber; a time delay orifice for venting the control chamber; and means for venting the control chamber through the time delay orifice until a flame is sensed such that the pressure in the control chasmber is reduced and the valve element is closed after a predetermined delay if no flame is sensed.
Claim 11
Dependent Claim
168 words
A gas control in a gas burning system comprising a safety valve in series with a main gas valve and with a pilot nozzle, the safety valve limiting the flow of gas to each of the main gas valve and the pilot nozzle and comprising: an input chamber for receiving gas; a normally closed valve element for preventing gas flow from the input chamber to the main gas valve and to the pilot nozzle; a control chamber; valve control means responsive to a pressure differential between the control chamber and the input chamber to open the valve element with increased pressure in the control chamber; a thermostatically controlled valve for increasing the pressure in the control chamber; a time delay orifice for venting the control chamber; and means for venting the control chamber through the time delay orifice until a flame is sensed such that the pressure in the control chasmber is reduced and the valve element is closed after a predetermined delay if no flame is sensed.
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) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |