US3574495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Burner control system
Assignee: Honeywell Inc
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Filing: 1969-12-11
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Granted: 1971-04-13
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Expires: 1989-12-11
Abstract
Abstract A fuel burner control system which includes a flame detecting unit and an electrically heated safety switch for safely starting and operating a fuel burner. The burner control system utilizes a time delay circuit for purging a combustion chamber prior to a trial for ignition. The system includes a conventional fan relay, ignition relay, and flame relay, but also includes a fourth relay and series connected silicon-controlled rectifier connected to lock the system out or cause the safety switch to heat in the event of a loss of flame signal after the system has properly been started, or in the case of a false flame signal occurring during the purge timing period.
Inventors
- 👤 William R Landis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:42
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/20; F23N5/203; F23N5/02; F23N5/08; F23N5/082; F23N2227/00; F23N2227/04; F23N2229/00; F23N2233/00; F23N2233/06; F23N5/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
264 words
A control system adapted to operate fuel burner means having flame sensor means to sense the presence or absence of flame at said burner means, and safety switch means to shutdown said fuel burner means in the event of a malfunction of said system or said burner means, including: control voltage supply means responsive to a demand for operation of said burner means to energize said control system; purge timer means energized by said voltage supply means and including switch means to time a purge period prior to ignition of said burner means and said switch means initiating the ignition of said burner means; sensor means responsive to flame connected to latching switch means; and flame responsive switch means; said latching switch means normally energizing said flame responsive switch means in response to flame at said sensor means with operation of said latching switch means and the subsequent operation of said flame responsive switching means providing operation of said burner means in normal operation until said control voltage supply means is removed at the end of said demand for operation of said burner means; said sensor means and latching switch means operating in rEsponse to flame occurring during the purge period to in turn disable said purge timer means to prevent ignition at said burner means and to energize said safety switch means; said sensor means and latching switch means operating said safety switch means to lockout the operation of said system in the event said sensor means indicates the absence of flame after the initial sensing of flame subsequent to the purge period.
Claim 2
Dependent Claim
264 words
A control system adapted to operate fuel burner means having flame sensor means to sense the presence or absence of flame at said burner means, and safety switch means to shutdown said fuel burner means in the event of a malfunction of said system or said burner means, including: control voltage supply means responsive to a demand for operation of said burner means to energize said control system; purge timer means energized by said voltage supply means and including switch means to time a purge period prior to ignition of said burner means and said switch means initiating the ignition of said burner means; sensor means responsive to flame connected to latching switch means; and flame responsive switch means; said latching switch means normally energizing said flame responsive switch means in response to flame at said sensor means with operation of said latching switch means and the subsequent operation of said flame responsive switching means providing operation of said burner means in normal operation until said control voltage supply means is removed at the end of said demand for operation of said burner means; said sensor means and latching switch means operating in rEsponse to flame occurring during the purge period to in turn disable said purge timer means to prevent ignition at said burner means and to energize said safety switch means; said sensor means and latching switch means operating said safety switch means to lockout the operation of said system in the event said sensor means indicates the absence of flame after the initial sensing of flame subsequent to the purge period.
Claim 3
Dependent Claim
52 words
A control system adapted to operate fuel burner means as described in claim 1 wherein said latching switch means includes a silicon-controlled rectifier and series connected relay means; said silicon controlled rectifier upon conducting energizing said relay means and maintaining said relay means energized until said control voltage supply means is deenergized.
Claim 4
Dependent Claim
37 words
A control system adapted to operate fuel burner means as described in claim 2 wherein said relay means is an electromagnetic relay with at least one normally open contact connected to control said flame responsive switch means.
Claim 5
Dependent Claim
47 words
A control system adapted to operate fuel burner means as described in claim 3 wherein said control voltage supply means includes a controller and bridge means adapted to be connected to an alternating current source and having a direct current potential output to energize said control system.
Claim 6
Dependent Claim
31 words
A control system adapted to operate fuel burner means as described in claim 1 wherein said flame at said burner means to which said sensor means responds generates an ultraviolet output.
Claim 7
Dependent Claim
51 words
A control system adapted to operate fuel burner means as described in claim 5 wherein said latching switch means includes a silicon-controlled rectifier and series connected relay means; said silicon-controlled rectifier upon conducting energizing said relay means and maintaining said relay means energized until said control voltage supply means is deenergized.
Claim 8
Dependent Claim
37 words
A control system adapted to operate fuel burner means as described in claim 6 wherein said relay means is an electromagnetic relay with at least one normally open contact connected to control said flame responsive switch means.
Claim 9
Dependent Claim
47 words
A control system adapted to operate fuel burner means as described in claim 7 wherein said control voltage supply means includes a controller and bridge means adapted to be connected to an alternating current source and having a direct current potential output to energize said control system.
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) | 1974-04-12 | 1974-10-12 | 1975-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-12 | 1978-10-12 | 1979-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-12 | 1982-10-12 | 1983-04-13 | $7700.00 | Window Closed / Lapsed |