US3589848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oil burner control system
Assignee: Liberty Combustion Corp
•
Filing: 1968-08-06
•
Granted: 1971-06-29
•
Expires: 1988-08-06
Abstract
Abstract Oil burner control system employing a control transformer the primary impedance of which varies in response to secondary loading by a temperature controller, whereby the variation causes energization of the control circuit. The full specification should be consulted for an understanding of the invention.
Inventors
- 👤 William F Potts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:31
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/20; F23N5/203; F23N5/02; F23N5/08; F23N5/082; F23Q; F23Q5/00; F23N2227/00; F23N2227/36; F23N2229/00; F23N2239/00; F23N2239/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
357 words
For use in an oil burner control system comprising a source of alternating current having one line and another line, an oil burner having a blower and pump motor, an air spark gap disposed adjacent the oil burner to ignite fuel issuing therefrom, a spark-generating apparatus connected to said air spark gap, a thermostatic switch, a flame sensor having low resistance in presence of flame and high resistance in absence of flame, a burner control circuit comprising connections extending to said source of alternating current, to said motor, to said air spark gap, to said generating apparatus, and to said flame sensor, a series circuit disposed across said source of alternating current comprising from said one line the normally closed contacts of a heat actuated circuit breaker, one winding of a two winding control transformer having a high impedance when the other winding is open circuit, and a low impedance when said other winding is short-circuited by said thermostatic switch, the winding of an electromechanical relay, the aNode and cathode of a silicon-controlled rectifier in that order and the heater of resistance of said circuit breaker, to said other line, a first resistance means having a tap connection connected across said relay winding and said silicon controlled rectifier to provide a voltage between said tap connection and said other line, said voltage having a higher value when said silicon-controlled rectifier is conducting than otherwise, means for triggering said silicon-controlled rectifier when said thermostatic switch is closed and said sensor senses the absence of flame on each half cycle when said one line is positive, a second resistance means comprising two resistors in series disposed across said relay winding, silicon-controlled rectifier and heater resistance, their midpoint being connected through a first normally open contact of said relay to the anode of said silicon-controlled rectifier, whereby when said relay is initially energized by the conduction of said silicon-controlled rectifier and said first normally open contact closes said relay remains energized through said second resistance means regardless of the conduction state of said silicon-controlled rectifier, so long as said thermostatic switch is closed and said circuit breaker contact is closed.
Claim 2
Dependent Claim
357 words
For use in an oil burner control system comprising a source of alternating current having one line and another line, an oil burner having a blower and pump motor, an air spark gap disposed adjacent the oil burner to ignite fuel issuing therefrom, a spark-generating apparatus connected to said air spark gap, a thermostatic switch, a flame sensor having low resistance in presence of flame and high resistance in absence of flame, a burner control circuit comprising connections extending to said source of alternating current, to said motor, to said air spark gap, to said generating apparatus, and to said flame sensor, a series circuit disposed across said source of alternating current comprising from said one line the normally closed contacts of a heat actuated circuit breaker, one winding of a two winding control transformer having a high impedance when the other winding is open circuit, and a low impedance when said other winding is short-circuited by said thermostatic switch, the winding of an electromechanical relay, the aNode and cathode of a silicon-controlled rectifier in that order and the heater of resistance of said circuit breaker, to said other line, a first resistance means having a tap connection connected across said relay winding and said silicon controlled rectifier to provide a voltage between said tap connection and said other line, said voltage having a higher value when said silicon-controlled rectifier is conducting than otherwise, means for triggering said silicon-controlled rectifier when said thermostatic switch is closed and said sensor senses the absence of flame on each half cycle when said one line is positive, a second resistance means comprising two resistors in series disposed across said relay winding, silicon-controlled rectifier and heater resistance, their midpoint being connected through a first normally open contact of said relay to the anode of said silicon-controlled rectifier, whereby when said relay is initially energized by the conduction of said silicon-controlled rectifier and said first normally open contact closes said relay remains energized through said second resistance means regardless of the conduction state of said silicon-controlled rectifier, so long as said thermostatic switch is closed and said circuit breaker contact is closed.
Claim 3
Dependent Claim
160 words
For use in an oil burner control circuit, a two-winding control transformer to electrically isolate said control circuit from a heat demand switch such as a thermostatic actuated switch, comprising a transformer having a first winding and a second winding and a ratio of first winding turns to second winding turns of at least four to one, said second winding having connections extending to said demand switch, said first winding being connected in series with other circuit elements of said control circuit across a source of alternating current power, whereby when said demand switch is open said first winding limits the current flow to said other circuit elements to prevent the operation of said control circuit, and when said demand switch is closed the impedance of said first winding is greatly reduced by short circuiting effect of said closed demand switch, to increase the flow of current to said other circuit elements to permit the operation of said control circuit.
Claim 4
Dependent Claim
160 words
For use in an oil burner control circuit, a two-winding control transformer to electrically isolate said control circuit from a heat demand switch such as a thermostatic actuated switch, comprising a transformer having a first winding and a second winding and a ratio of first winding turns to second winding turns of at least four to one, said second winding having connections extending to said demand switch, said first winding being connected in series with other circuit elements of said control circuit across a source of alternating current power, whereby when said demand switch is open said first winding limits the current flow to said other circuit elements to prevent the operation of said control circuit, and when said demand switch is closed the impedance of said first winding is greatly reduced by short circuiting effect of said closed demand switch, to increase the flow of current to said other circuit elements to permit the operation of said control circuit.
Claim 5
Dependent Claim
63 words
An oil burner control circuit as set forth in claim 1 wherein the voltage between said tap connection and said other line may be extended to the trigger circuit of the discharge means of a capacitive-discharge ignition voltage generator comprising said spark-generating apparatus whereby sparking occurs at said air spark gap when said flame sensor senses the absence of flame at said burner.
Claim 6
Dependent Claim
288 words
For the ignition and control of an oil burner of the blue flame-type burning, in addition to a mixture of oil and air, recirculated combustion gases and oil otherwise evaporated by heat, including an air spark gap and a flame-responsive device; in combination, a source of alternating current power; a spark generator apparatus comprising a capacitance, a stepup transformer the primary of which is in series with the capacitance and the secondary of which is connected across the air spark gap, means to unilaterally charge the capacitance from said source of power and unidirectional means for repetitively discharging said capacitance through the transformer primary and disposed in a first housing; a burner control circuit including connecting means extending to said source of power, to said generator apparatus, to said flame-responsive device and to a heat demand switch, relay switching means initially responsive to said demand switch demanding heat and to said flame-responsive device indicating the absence of flame at the burner to apply said source of power to said generator apparatus and to said blue flame burner, said switching means responsive thereafter to said demand switch only, means to terminate the operation of said generator apparatus when said flame-responsive device indicates the presence of flame at the burner and safety shutoff means havinG contacts adapted to open the circuit to said source of power after a predetermined period when energized, said shutoff means being energized in the absence of flame indication and not energized in the presence of flame indication, said control circuit disposed in a second housing; both said first and second housings disposed on a common interconnecting base, the whole occupying a space volume less than that occupied alone by a line-operated oil burner ignition transformer.
Claim 7
Dependent Claim
288 words
For the ignition and control of an oil burner of the blue flame-type burning, in addition to a mixture of oil and air, recirculated combustion gases and oil otherwise evaporated by heat, including an air spark gap and a flame-responsive device; in combination, a source of alternating current power; a spark generator apparatus comprising a capacitance, a stepup transformer the primary of which is in series with the capacitance and the secondary of which is connected across the air spark gap, means to unilaterally charge the capacitance from said source of power and unidirectional means for repetitively discharging said capacitance through the transformer primary and disposed in a first housing; a burner control circuit including connecting means extending to said source of power, to said generator apparatus, to said flame-responsive device and to a heat demand switch, relay switching means initially responsive to said demand switch demanding heat and to said flame-responsive device indicating the absence of flame at the burner to apply said source of power to said generator apparatus and to said blue flame burner, said switching means responsive thereafter to said demand switch only, means to terminate the operation of said generator apparatus when said flame-responsive device indicates the presence of flame at the burner and safety shutoff means havinG contacts adapted to open the circuit to said source of power after a predetermined period when energized, said shutoff means being energized in the absence of flame indication and not energized in the presence of flame indication, said control circuit disposed in a second housing; both said first and second housings disposed on a common interconnecting base, the whole occupying a space volume less than that occupied alone by a line-operated oil burner ignition transformer.
References Cited (Backward Citations)
US3027933A
Cited
US3443752A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |