Patent US3744954A successfully refreshed from Google Patents.
US3744954A
Expired / Lapsed
US
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Fuel-leak detector and safety system
Assignee: Individual
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Filing: 1971-05-27
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Granted: 1973-07-10
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Expires: 1991-05-27
Abstract
Abstract A safety control system for detecting and stopping leakage of fuel through the fuel-valve in burner fully automatic installations subject to such leakage problems because of the presence of fuel under pressure at the fuel-valve for periods of time when the burner is not actually lighted. The system includes a lead-detector, such as a pressure switch, located downstream of the main fuel-valve for closing an auxiliary fuel-valve installed in tandem with the main valve, so that when leakage through the main valve occurs, the auxiliary valve closes and immediately stops the leak. It also trips a lockout circuit that prevents reignition of the burner. A discriminator device is employed for nullifying the action of the leak-detector on normal flow of fuel to the burner nozzle. While the leak safety of the present invention immediately stops the leak by closing the auxiliary fuel-valve, it permits the master burner control to progress through its normal cycle of operations during both its shut-down and start-up periods to the point just before ignition takes place, so that any fuel that may have leaked will be purged during the purge periods of the burner cycle, thereby providing a safeguard against ignition of the leaked fuel when the burner is restarted. A leak alarm is provided to signal when the leakdetector senses a fuel leak, and a separate manual reset device is provided so that the burner cannot be restarted accidentally following what might be erroneously thought to be a routine flame-out.
Inventors
- 👤 E Faulkner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:49
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/24; F23N5/245; F23N5/22; F23N2227/00; F23N2227/04; F23N2229/00; F23N2231/00; F23N2231/18; F23N2231/20; F23N2233/00; F23N2233/06
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
216 words
In an automatic fuel-burner system having a fuel-supply line, a main fuel-valve in said fuel-supplying line for controlling the flow of fuel to the burner, a fuel igniter for initiating a flame in a combustion chamber during each operating cycle of the fuelburner system and operating controls for said system having means for sequencing the operating cycle and for opening said main fuel-valve during scheduled periods in said operating cycle with the portion of said fuel-supply line upstream of said main fuelvalve under constant fuel-pressure, a fuel-leak detector and safety system comprising in combination an auxiliary fuel-valve in said fuel-supply line in tandem with said main fuel-valve, a leak-detector in said fuel-supply line downstream of said main fuel-valve operable for sensing fuel leaked by said main fuelvalve both before and after the source of ignition is established, control means for closing said auxiliary fuel-valve in response to the action of said leak-detector on sensing fuel in said supply-line downstream of said main fuel-valve, said control means being connected to said burner-operating controls indePendently of said main fuel-valve, and discriminator means for nullifying the action of said leakdetector on said control means for said auxiliary valve during the scheduled periods when said main fuel-valve is open, such that said auxiliary fuel-valve remains open during said scheduled periods.
Claim 2
Dependent Claim
216 words
In an automatic fuel-burner system having a fuel-supply line, a main fuel-valve in said fuel-supplying line for controlling the flow of fuel to the burner, a fuel igniter for initiating a flame in a combustion chamber during each operating cycle of the fuelburner system and operating controls for said system having means for sequencing the operating cycle and for opening said main fuel-valve during scheduled periods in said operating cycle with the portion of said fuel-supply line upstream of said main fuelvalve under constant fuel-pressure, a fuel-leak detector and safety system comprising in combination an auxiliary fuel-valve in said fuel-supply line in tandem with said main fuel-valve, a leak-detector in said fuel-supply line downstream of said main fuel-valve operable for sensing fuel leaked by said main fuelvalve both before and after the source of ignition is established, control means for closing said auxiliary fuel-valve in response to the action of said leak-detector on sensing fuel in said supply-line downstream of said main fuel-valve, said control means being connected to said burner-operating controls indePendently of said main fuel-valve, and discriminator means for nullifying the action of said leakdetector on said control means for said auxiliary valve during the scheduled periods when said main fuel-valve is open, such that said auxiliary fuel-valve remains open during said scheduled periods.
Claim 3
Dependent Claim
185 words
A fuel-leak detector and safety system as defined in claim 1, wherein said auxiliary fuel-valve is provided with electro-mechanical actuating means in a first control circuit connected to a source of power independently of the controls for said main fuel-valve, said control means for closing said auxiliary fuel-valve comprising a switching device in a second control circuit with said leak-detector connected to the power source independently of said main-fuel valve controls, said leak-detector comprising a fuel-sensitive switch in said second circuit arranged to close in response to the presence of fuel in said fuel-supply line downstream of said main fuel-valve, said switching device having a first set of switch contacts in said first control circuit for closing said auxiliary fuel-valve, said discriminator means comprising a set of normally closed timer contacts in said second control circuit co-ordinated with said sequencing means to open prior to said scheduled periods and to close following said scheduled periods, and a lock-out device including a second set of switch contacts of said switching device in a holding circuit therefor connected to said power source independently of said burner-operating controls.
Claim 4
Dependent Claim
55 words
A fuel-leak detector and safety system as defined in claim 1, which further includes ignition disabling means responsive to said leak-detector and connected in series with said fuel igniter for preventing operation thereof when fuel is sensed by said leakdetector, said discriminator means being also effective in de-activating said ignition-disabling means during such scheduled periods.
Claim 5
Dependent Claim
75 words
The combination defined in claim 1, wherein said fuel-burner system is provided with conventional alarm systems including a flame-failure alarm and said fuel-leak detector and safety system includes a leak-alarm which is activated completely independently of said conventional alarm systems in response to the action of said leak-detector on sensing fuel downstream of said main fuel-valve, said discriminator means having provision for nullifying the action of said leak-detector on said leak-alarm during said scheduled periods.
Claim 6
Dependent Claim
134 words
The combination defined in claim 1, wherein said fuel-burner system includes an electrically powered fuel igniter and said burner-operating controls are provided with an ignition circuit for supplying electrical energy to said fuel igniter, as well as with conventional alarm systems including a flame-failure alarm and said fuel-leak detector and safety system includes an ignition-disabling switch for opening said ignition circuit and a leak-alarm, said ignition-disabling switch and leak-alarm being controlled by said leak-detector completely independently of said burner-operating controls and of said conventional alarm system for preventing operation of said igniter and for actuating said leak-alarm, respectively, when fuel is sensed by said leak-detector, said discriminator means having provision for preventing the opening of said ignition circuit and the actuation of said leak-alarm during said scheduled periods when said main fuel-valve is open.
Claim 7
Dependent Claim
212 words
A fuel-leak detector and safety system for an existing automatic fuel-burner having a main fuel-valve in a fuel-supply line for controlling the flow of fuel to the burner, a fuel igniter and operating controls for said fuel-burner having means for sequencing the operating cycle of said burner including the scheduled opening of said main fuel-valve at a predetermined point in said cycle, the portion of said fuel-supply line upstream of said main fuel-valve being under constant fuel-pressure, said fuel-leak detector and safety system comprising in combination an auxilIary fuel-valve for installation in said fuel-supply line in tandem with said main fuel-valve, a leak-detector for installation in said fuel-supply line downstream of said main fuel-valve and operable for sensing fuel leaked by said main fuel-valve both before and after the source of ignition is established, control means for closing said auxiliary fuel-valve in response to the action of said leak-detector on sensing fuel in said supply-line downstream of said main fuel-valve, said control means having provision for being operatively connected to said burner-operating controls independently of said main fuel-valve, and discriminator means for nullifying the action of said leak-detector on said control means during scheduled periods when said main fuel-valve is open, such that said auxiliary fuel-valve remains open during said scheduled periods.
Claim 8
Dependent Claim
212 words
A fuel-leak detector and safety system for an existing automatic fuel-burner having a main fuel-valve in a fuel-supply line for controlling the flow of fuel to the burner, a fuel igniter and operating controls for said fuel-burner having means for sequencing the operating cycle of said burner including the scheduled opening of said main fuel-valve at a predetermined point in said cycle, the portion of said fuel-supply line upstream of said main fuel-valve being under constant fuel-pressure, said fuel-leak detector and safety system comprising in combination an auxilIary fuel-valve for installation in said fuel-supply line in tandem with said main fuel-valve, a leak-detector for installation in said fuel-supply line downstream of said main fuel-valve and operable for sensing fuel leaked by said main fuel-valve both before and after the source of ignition is established, control means for closing said auxiliary fuel-valve in response to the action of said leak-detector on sensing fuel in said supply-line downstream of said main fuel-valve, said control means having provision for being operatively connected to said burner-operating controls independently of said main fuel-valve, and discriminator means for nullifying the action of said leak-detector on said control means during scheduled periods when said main fuel-valve is open, such that said auxiliary fuel-valve remains open during said scheduled periods.
Claim 9
Dependent Claim
48 words
A fuel-leak detector and safety system as defined in claim 6, which further includes ignition-disabling means responsive to said leak-detector for connection in series with the fuel igniter in said automatic fuel-burner and said discriminator means being also effective in de-activating said ignition-disabling means during such scheduled periods.
Claim 10
Dependent Claim
98 words
A fuel-leak detector and safety system as defined in claim 7, wherein said auxiliary fuel-valve is provided with electro-mechanical actuating means in a first control circuit capable of being connected to a power source independently of the controls for the main fuel-valve in said fuel-burner, said control means for closing said auxiliary fuel-valve comprising a switching device in a second control circuit with said leak-detector capable of being connected to a power source independently of said main fuel-valve controls, said switching device having a first set of switch contacts in said first circuit for closing said auxiliary fuel-valve.
Claim 11
Dependent Claim
53 words
A fuel-leak detector and safety system as defined in claim 8, wherein said discriminator means comprises switch-means in said second control circuit and means co-ordinated with said scheduled periods when said main fuel-valve is open for opening said switch-means prior to said scheduled periods and for closing said switch-means following said scheduled periods.
Claim 12
Dependent Claim
34 words
A fuel-leak detector and safety system as defined in claim 9, wherein said switch-means comprises a device selected from the group consisting of a timer switch, a control-relay switch and a time-delay relay switch.
Claim 13
Dependent Claim
52 words
A fuel-leak detector and safety system as defined in claim 10, in which said ignition-disabling means comprises a second set of switch contacts of said switching device in the circuit to be connected in series with said fuel igniter, said second control circuit being connected in parallel with said first control circuit.
Claim 14
Dependent Claim
48 words
A fuel-leak detector and safety system as defined in claim 11, which further includes a leak-alarm circuit connected in parallel with said first control circuit, said switching device having a third set of switch contacts in said leak-alarm circuit for de-activating said leak-alarm circuit during said scheduled periods.
Claim 15
Dependent Claim
69 words
A fuel-leak detector and safety system as defined in claim 12, which further includes a holding circuit for said switching device by-passing said leak-detector for locking out the operating controls for said burner, said switching device having a fourth set of said switch contacts in said holding circuit for closing said holding circuit when said switching device is energized and a manual reset switch for de-energizing said holding circuit.
Claim 16
Dependent Claim
128 words
A fuel-leak detector and safety system as defined in claim 13, wherein said auxiliary fuel-valve is open when said electro-mechanical actuating means is energized, said leak-detector comprising a nomally open fuel-sensitive switch which closes on sensing fuel in said fuel supply-line, said switching device comprising a control relay having a plurality of switch contacts comprising said first, second and third sets of switch contacts, said first and second sets oF switch contacts being closed when said control relay is de-energized and said third and fourth sets of contacts being open when said control relay is de-energized, all said switch contacts being reversed when said control relay is energized, said discriminator switch means being disposed in said second control circuit between said leak-detector pressure switch and said control relay.
Claim 17
Dependent Claim
50 words
A fuel-leak detector and safety system as defined in claim 1, wherein said fuel-burner system further includes forced-draft means, said control means for closing said auxiliary fuel-valve being also independent of said forced-draft means such that said forced-draft means remains operable for purging combustible fuel-air gases from the combustion chamber.
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) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |