US1774137A - Oil burner - Google Patents

Description

Aug. 26,1930. J GOOD r AL, 1,174,137 on. BURNER v Filed July 8`, 1925 TRnNs FORMER OIL MVT SEfn/o No Tan' INVENTO Patented Aug. 26, 1930 UNITED STATES PATENT oFFIcE JOHN GOOD, F GARDEN CITY, AND ELLIOT O. SEAVER, OF MINEOLA, NEW YORK, ASSIGNORS TO GOOD INVENTIONS CO., OF NEW YORK, Y., A CORPORATIONVOF NEW YORK Application filed July 8,

The invention relatesto oil burners of the type intended for house heating purposes, although useful elsewhere, and its object is to provide a safe automatic control system u for such apparatus whereby, among other things, it is made impossible for the combustible and an igniting temperature to coexist in the combustion space ofv the furnace, except according to the propersequence or during normal combustion, and whereby, especially, the resumption of the burner-operating current, after an interruption caused by thermostat control or otherwise, cannot produce delivery of fuel or the operation of the ignition means until after 1 the lapse of a period of time, say ten minutes or so, suiicient to allow the cooling of all internal parts of the furnace to below ignition temperature. The invention involves various features of control, looking toward the avoidance of accident and dangerous conditions, all of which will be made apparent in thc following description, and man),1 of which will be recognized as capable of application with advantage to existing control systems of other types. 'Y v In the accompanying drawing Figure 1 is a general diagram of the preferred form of the new system, Figure 2 being a detail elcvation of the timing. device or servo-motor, and Figure 3 a diagram of the control cycle.

The burner proper with which this invention is adapted for use may be of any desired type and is diagrammatically representd in the drawings as comprising a fan blower l and a fuel spray nozzle 2 within asuitable housing, the fan being driven by an electric motor 3. An igniter for the burner is indicated at n hot wire igniter, which becomes incandescent when energized, although any suitable means of ignition can be easily brought within the control ofthe present system by suitable adaptation. As al means of avoiding oil leakage when the burner" motor is not energized, an oil valve is ordinarily applied to the oil line to the burner, arranged to close whenever the burner motor stops running.

.50 Such an oil valve is controlled by the electro- 4, being in this case an electric resistance orv OIL BURNER 1925. Serial No. 42,145.

the burner except when the latter is opera-tf I ing and then only to sto it and has no control over the timing devlce except to start it in action. This timing deviceA starts the burner motor and then shifts the' control of the lat-ter over to the thermostat, and forbids resumption of burner operation until after the cooling period has intervened. The room thermostat in the present ycase is an ordinary bi-metallic strip adapted to Hex to the right as it cools and make a double contact on such movement, one-contact (22) being made directly by the end of the bi-metallic arm itself and the other (28) by means of a flexible finger securedt' and moving with it; the design will be clear from the diagram. The double contact is preferred but a single 'contact thermostat 'could' be made to sufce 'perature is to be controlled, the present vsystem could also be controlled by variation of pressure as by means of a, so-cal'led pressurestat adapted to respond either directly or 1ndirectly to changes of boiler pressure. For convenience in this description and in the claims all such heat or pressure-sensitive devices are included in the term room thermostat.

fore it functions to start or permit the start- P ing of, the burner motor. Within the category of devices suitable for this purpose are included motors, thermostatic elements and dash pots when suitably controlled and regu- The timing device above referred to can be lated. Preferably the timing device cnstituted of a member having a fixed cycle and the present case,

` at contact point 32.

so organized that when once started, its full cycle must be carried out before it can repeat any function. 'A part of such cycle is' allotted to the energiz'ation of thegburneroperating motor and its igniter and appurtenant parts, and the rest, and greater part, is merely time consuming. By this division o f the cycle, two successive motor energizations cannot occur without a time interval between them which is made long enough to allow all heated parts in the furnace to cool down to below an igniting temperature, thereby precluding the possibility of an explosion on the resumption of the -action of the igniter or of the fuel delivery. The delay thus involvedand which may be teni minutes or more, is found to be unobjection able in an automatic system and represents a positive assurance of safety. In the present case, the t1m1ng device is a small motor, herein called and marked the servo-motor. `ItVA 1s geared through appropriate reduction gearing to impart a slow drive to a commutator 6 and two adjacent cams 7 and 8, at the rate of about one revolution in ten or twelve I nlnutes. These parts are yshown in elevation 1n Fig. 2 and their respective developments appear in the diagram of Fig. l as a matter of convemence in observing the sequencel of operations.

The function of the lcommutator is to controlits own armature circuit and the igniter c1rcu1t. The function ofthe cam 7 is to lift or move the switch armature 9 of the holding magnet 10 so vas to close the circuit gap at contact polnt 11.A When this armature has so been moved, the eld of the magnet 10 retams 1t closed, (provided the magnet`circuit 1s not opened elsewhere) independently of .further control by saidcam. When the holdlng armature is released it falls, by gravity in and closes the circuit gap The cam 8 1s for the purpose of depressing a plunger or striker 12 against a spring and releasing 1t so as to lcause it to strike the switch armature 13 and knock it into its clrcult-closlng position in which it, like the armature 9, 1s then held blt-beheld of the magnet 14:.v In itsv normal ondropped positlon, armature 13 is out pf the magnet fieldand cannot be closed bythe effect of the magnet alone. The magnet 14 is hereiny referred to as the motor switch magnet, in-

asmuch as the closure, .by its armature 13, of the gaps at contact points 15 completes the motor-operating circuit 16. This circui't,it will be seen, is connected directly to the main supply leads 17 of the house circuit and ma be assumed to carry-the usual 110 volt cur' rent. Inasmuch 'as the function of the cams 7 and 8 is' merely to cause their respective thus they controlling circuit for the servo f motor. in

The high potential or house current 1s also used for igniting the burner wher hot wire ignition is employed andthe ignition circuit in the present case is marked 21 being connected to leads 19.

Assuming that the system is out of action, commutator 6 occupies the position, with respect toits several brushes, which `is indicated in Figure 1. The three conducting strips 23, 24 and 25 of the commutator are all connected together, as indicated by dotted lines, and two of them, `23 and 24, are engaged with their respective brushes whereby a circuit will be seen to be ,established which in' in rotation. The short arm of the thermostat closes the gap at its contact 28 slightly before or coincidently withy the closure of gap at 22 and its effect is to establish, but not to complete, a circuit which includes the secondary of the transformer, the two magnets above referred to, .the gap (open) at 11, armature 9 and Wire 27 back to the thermostat.-

This circuit is referred to as a holding circuit, since its principal function is to hold both armatures' in circuit-closing positions, but it is open, or uncompleted, when the commutator starts to rotate. This circuit `is shown by the heavy line in the diagram.

The lirst etl'ect of the rotating commutator is to bring the commutator strip 30 into contact with the two adjacent brushes of the igniter circuit 21 and thus close the igniter circuit; this mayoccur in about fteen seconds after the servo-motor'has started; no

other action results from thiscircuit closure, but the igniter, if a resistance element, begins y to get hot. Before theigniter strip 30 has 'passed from under its brushes, the cam 7 will have revolved to such an extent as to lift its armature and thereby close the gap at 11 and armatures to be-placed in circuit-closing po'- thus complete the holding circuit above refor as long as the room thermostat maintains its contact at 28. The cam 8 will also have depressed the plungei 12 and shortly after the closure of the holding circuit by cam 7, will have released the plunger so as to cause it to strike t'he'motor switch armature 13 and v close the motor circuit already referred to.

\Vhen thus thrown into circuit-closing position the motor switch armature is put into the feldof its magnet as already explained and is thereafter retained in such position independently of any further operation of the cam 8 or the commutator. That is to sav, the servo-motor has started the burner motor and completed the holding and motor circuits and at the same time has relinquished lall further control of thosey parts, shifting such control to the 'holding circuit, that is to say, to the room thermostat. If the latter should open the gap 28, both armatures would drop and the burner would stop. Some 125 seconds have been consumed in the rotation of the commutator necessary to start the burner-operating motor and during that period the igniter 4 will have attained an igniting temperature so that en the delivery of fuel ignias of the servo-motor; closure by it of the gap at y22 can have no effect because the commutator brush at theother end of wire 26 is on the dead part of the commutator; closure of the gap at 28 can also have no effect because the holding circuit is broken by the gap at 11fa11d, as already described, that-.Gap cannot be closed until the armature 9 is lifted by the cam 7 and even if1 the gap at 11 should be closed in` some abnormal f way, the burner motor could not be started without the assistance of cam 8 and its spring/plunger. Thus afterevery period of burner action, or conversely, before any second igniter action, there must intervene a cooling period long enough to forestall fuel delivery into a furnace chamber hot enough to ignite it; once the burner has started it can-be stopped on the call lof the room thermostat but it cannot be restarted until the next stroke of the switch closing plunger'. The purpose in closing the switch by hammer stroke is to prevent any possibilty of the servo-motor stopping in a switch-closing position and thus holding the switch closed. p f

Any momentarycessation of the main current supply has the same effect as opening of tion occurs, followed by normal combustion.- gap 28 by the thermostat, since the de-ener- The commutator strip .3 0 is preferably long enough so that it does not run out from under its brushes for some seconds after the burner motor has started, in order to make ignition certain. ,A

Thereafter when the commutator strip 24 has moved out of contact with its brush, the

motor armature circuit above referred to is interrupted and the' servo-motor stops. It remains stopped for so. long as the holding lcircuit is active or the burner motor isrunis connected tothe lower contact`32 of the the holding circuit, (le-energizing magnets 10 and 14, and releasing both of their armatures, which -discontinues the burner operating current. vRelease of the holding armature 9 closes the .gap at 32 and thereby completes a servo-motor arma-ture circuit through wire 31, strips -25 and .23 connected back through wire 27 to the armature 9. This causes the servo-motor to resume operation and complete the rotation cycle of the commutator,

rotatingit until the brush of wire 31 runs off the end of strip 25 which is the normal or staltionary position, indicated in the diagram.

The time consumed in such continued or second rotation is approximately ten minutes and during that period the room thermostat is entirely out o'f control of the burner as well gizingy of the transformer de-energizes the magnets 1() and 14, their armatures drop and can only bere-closed after the commutat-orV has revolved to such extent as may be necessary to bring the cams 7. and 8 again into action upon them. If the current failure should occur, exactly at themoment of the cam closure of the gap at 11, no untoward effect can be produced on resumption, be-

` cause the motor switch armature 13 has not yet been closed, and a sufcient time interval intervencs between the operation of the two cams in any event to allow the igniter to reach an igniting temperature before theburner comes on. At all other times failure'of the current supply results in the opening of gap 11 which cannot be closed until the servomotor has performed the cooling period part of its cycle, represented by the length of commutator strip 25.

The sequence of the several operationsis illustrated in the cycle. diagram of Fig. .3 wherein it will `be seen that the resistance igniter is energized shortly after the timing device nor servo-motor starts rotation, and that some A119 seconds elapse before the burner motor 1s set in action. This interval is to allow the rcsistance'igniter to attain an igniting temperature before the fuel strikes.

between both.

time periodindicated from the servo stop position to the start position may be, as stated, about ten minutes to serve as a'cooling period for the interiorof furnace parts. .In-

5 asmuch as the commutator mechanism roby cam.8, as already ekplained.

Icease just at the moment ofclosing ofgap 11 It will be seen that while the system as' above described uses a double-contact thermostat, the two contacts 28 and 22 could, if

desired, be consolidated into one.

The switch device diagrammatically indicated at 33 will be understood to be the usual trip switch adapted to operate'in the case of leakage of oil, for the purpose of opening the v main current supply circuit until re-set by` hand.A A

We claim g 1. A burner control system comprising a burner motor, 4atiming device adapted to :m start the same, a room thermostat adapted to start said timing device, and means enabling the thermostat 4to stop said motoa` independently of the timing device.

2. A burner control system comprising a burner motor, a timing device adapted to start the same; a room thermostat adapted to start said device and stop/ said motor independently of the timingdevice,v and interrelated connections between said thermostat 40 and timing device whereby the latter interposes a cooling period between successi ve motor startings.

y 3. A burner control system comprising 4a burner motor, a timing device adapted to lclose 5 the switch thereof, aroom thermostat -adaptedtoastart said device in action and a Cir- .cu'it whereby the .thermostat holds said switch closed.

4. A burner control system comprising a burnr motor,a motor switch therefor,'a holding clrcuit and magnetic means energizedthereby adapted to hold said switch closed but lncapable of closing it, a timing device adapted for closing said switch and a room thermostat for 'starting said' timing device and controlling said circuit.

5. A burner control system comprsing a burner motor,.a motor switch therefor, a

m holding circuit -and magnetimens'energized .thereby adapted `to hold said switch closed, but incapableof closing it, a timing device arranged to lclose said switch but iii-j capable of holding it closed and of opening it,

'55 and a room thermostat in control of said cira burner motor, an electromagnet eratin motor, igniter and a room thermostat.

norma ly out of immediate control of said motor, in combination with mechanism started by the thermostatic action, adapted to energize the igniter and motor, and having means interposing a cooling interval between successive igniter energizations, and means whereby control of the burner-motor, when started, is transferred' from said mechanism to the room thermostat.

8. A burner control system comprising the combination with aburner-operating motor, an igniter and a room thermostat normally out of immediate control of said motor, of mechanism normally controlled by the thermostat, arranged to energizelirst the igniter and then-the motor and interpose a cooling interval betweensuccessive energizations of said igniter, and a holding circuit,inclu ding the `thermostat, established by the action of said mechanism.-

9. In an electric burner control system, a burner motor and an operating circuit therefor, an electromagnetic motor switch for said circuit, a room' thermostat adapted to close a gap in the motor switch circuit and a timcuit which includes said magnet and thermostat, whereby the latter is`in direct control of said magnet. l 11'. Inan electric burner control system, a burner motor, an electromagnet to `control the same, a room thermostat controlling a gap in the magnets circuit, a timing device also controlling a gap in said circuit, and acircuit for starting said-timing device in action having a thermostat.

12. In an electric burner-contrl system,

the" same, a room thermostat' controllingv a gap in the magnets circuita timingr device also controlling a gap in said circuit, a circuit for starting said timing device in action havinga gap also controlled by said thermostat, and means whereby failure of saidI gap also controlled by said y o lcontrol `ing device also controlling a gap in said magnets circuit also starts said timing 'device.

13. In a-f.. burner control system, a b urner 'motor, a motor switch therefor, a room thermostat, a timing device set in motion by the action ofsa'id thermostat and adapted to close said switch and stop its own mot-ion, independently of said thermostat, while the 'burner motor is energized, and means whereby said timing ldevice continues its motion when the burner motor is deenergized.

14. In a burner control system, a burner motor and igniter, a holding circuit for the burner motor, a servomotor adapted to energize said igniter and burner motor, establish said holding circuit and' then stopv its own motion, and meanscontrolled by said holding circuit for causing continued operation of said servomotor when said holding circuit is broken.

15. In a burner control system, a circuit including two magnets, the armature for one of said magnets being adapted to close said circuit, a device to 'move said armature tol circuit closing position, a burner motor circuit controlled by the armature of the other magnetv and means for causing the latter armature to close the burner motor circuitafter said magnet circuit has been closed.

16. In a burner control system, a room thermostat; a circuit containing a lgap controlled by said thermostat and also containing a holding magnet and a gap vadapted to be held closed by said magnet, eleetromotor means adapted for closing said last mentioned gap but incapable of opening it, AYand means whereby the room thermostat sets said means in action.

a double-contact room thermostat, a timing device started in action by a circuit through one of said contacts and a holding circuit including the other thermostat contact and established by the. action of said timing device. p 19. In a burnerv control system, a burne motor, and a double contact room thermostat normally out of direct control of said motor, in combination with an electrically operated vtiming device having a circuit including one .o f said thermostaty contacts wherebyj it is started, a holding circuit including the other ios'fffof said contacts, a magnet in sald holding circuit and means whereby said magnet controls the operating current to said motor.

20. In a burner control system, a burner motor, a resistance igniter and a room thermostat, in combinationv with a servo-motor, and means operated thereby for successively causing energization of the igniter and motor, said means including amagnet, an armature thereforand means driven by the servo-motor. for operating said armature. 21.- In a burner control system, a burneroperating motor and a resistance igniter, a magnet to control the motor, a room thermostat adapted 4to close a gap in the circuit of said magnet and a timing device adapted to close the igniter circuit and also controlling a gap in said magnet circuit. i

22. In a burner control system, the combination with a burner motor circuit and an igniter, of a room thermostat circuit, a timing device started in response to closure of the. room thermostat circuit, connections whereby the igniter, and, after an interval, the burner circuit are energized by the timinw device, said timing device being adapted subsequently to cause de-energization of the igniter and means whereby opening of the thermostat circuit stops thegmotqr.

23. In a burner control system, the combination of a room thermostat circuit-and a timing device, means whereby the room ther- -mostat starts the burner through said timing device and means whereby opening of the room thermostat circuit stops the burner independently of the timing device.

24. In a burner control system a room thermmostat circuit, a burner motor started in re sponse to closure of said circuit and stopped in response to opening thereof, an igniter energized in response to closure of the room thermostat circuit, means for interposingr a delay between the energization of the igniter and starting of the burner motor andmeans for le-energizing the igniter independently of the room thermostat circuit.

25. In a burner control system, a room ther.- mostat circuit, a burner motor started in response to closure of said circuit and stopped in response to opening thereof, an igniter, and means for interposing a delay between successive motor energizations.

In testimony whereof, we have signed this specification.

JOHN GOOD. ELLIOT O. SEAVER.

' y DISCLAIMER 1',774:,137*.`.-John Good, Garden City, and Elliot 0. Seaoer, Mineola, N. Y. OILd BURNER. Patentdated lAugust 26, 1930. -Disclaimer filed August 14, 1935, ly the assignee, Good Inventions 0o. ereby enters this disclaimer, to Wit:`

(1) From claim 3, all burner control systems wherein the room thermostat holds the burner motor switch closed through the agency of the timing device.

(2) From claim 25, all burner control systemsexcept those wherein the igniter is rendered active in response to the closure of the room thermostat.

[Oficial Gazette Sptember 10, 1935.]

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