US1630702A

US1630702A - A cobpobation

Info

Publication number: US1630702A
Authority: US
Publication date: 1927-05-31
Anticipated expiration: 1944-05-31

Description

May 31, 1927.

H. C. HUBBELL IGNITION SYSTEM Fon BURNERS Filed April 2, 1925 2 Sheets-Sheet 1 INVEN TOR.

A TTORNEYS.

IGNITION SYSTEM FOR BURNERS Filed April 2. 1925 2 Sheets-Sheet 2 IN VEN TOR.

A TTORNEYS.

Patented May 31, 1927.

UNITED STATES A 1,630,702 PATENT oFFlcE.

HARRY C. HUBBELL, F WEST'SPBINGFIELD, MASSACHUSETTS, ASSIGNO'B TO WIGO ELECTRIC! COMPANY, OF WEST SPRINGFIELD, MASSAQHUBETTB, A CORPORATION OF MASSACHUSETTS.

IGNITION SYSTEM FOR BUBNEBS.

Application tiled April 2, 1925. Serial I0. 20,949.

This invention relates to improved means for controlling the ignition means of a burner and, while the invention is. capable of other and general applications, it has been developed and is particularly suitable for use in connection with oil burners.

The invention will be disclosed in a form developed for use in connection with electrical or spark ignition means and as adapted to cut in and cut out such an ignition means whenever necessary. In certain respects, as will be evident from the description to follow, the invention is not restricted to the use of s ark ignition means and might, for examp e, be made to alternately reduce andenlarge the flame of a gas pilot at proper times, according to the necessity therefor as manifested by the presence or lack of a flame from the burner. The reference hereinafter to s ark ignition is, therefore, not necessarily lntended to exclude all other forms of ignition means although the spark ignition means is referred.

The pro lem of this invention may be very simply stated. It is to cut out the ignition means as soon as the burner has been ignited and to render the ignition means again available for the igniting function as soon as the rburner stops. The solution'of the problem is not so easy as will be evident from a study 2 of the prior art, .which shows that the problem has been 'attacked from many widely differing ang'les. Among the more common forms of control, found in the prior art is that which functions according to time. That is the ignition is cut in on starting the flow of fuel to the burner and remains in for a definite time interval. This is not as satisfacto as it should be because it is en- 40 tirely possible for the time interval to elaise lwithout i ition actually occurring. he ignition slgilduld be stopped only after its work has actually been accomplished, as manifested by a liamel issuing from the burner, which seems to require a control responsive to burner heat. A representative t of such heat control is the flame type t ermostat found in the rior art as operatin a switch or valve. guch a'thermostat whi e apparently suitable from theoretical considerations, does not prove satisfactory in practice because it is not suiicientlyrquick acting for the purpose. The difficulty arises because the thermostat is subjected to very because it has not cooled sufficiently and oil will be thrown into the fire box to be later ignited with possible disastrous results. While all sorts of precautions have been taken to cope with such emergencies, in.- stances of ex losions directly traceable to slow action o an ignition controlling thermostat have occurred. The thermostat is therefore not wholly reliable and does not adequately meet al the conditions which must be met in practice to insure safe and reliable automatic operation of an oil burner.

The object of this invention is to provide a controlling device which is responsive to heat, as is the thermostat, but which will function to quickly cut out the ignition means `once its work has been accom lished, as manifested by the presence of me at the burner and which after the burner has stopped w' 1 a ain cut in the ignition simultaneously 'wi the starting of the burner and. without any delai. 4

In attaining this o ject, a novel form of control device is arranged in a1. electrical circuit which also includes an' electrically operated device for cutting in and out the ignition means. 'The control device includes an air p and through which no current flows w en the burner is not ignited. The invention depends, it is thought, on the ioni` zation of the air between the electrodes of the-control device caused by the heat from the flame of the ignited oil burner and the practical result is that, on such a condition, current sufficient to o rate said device flows through the circuit. its simplest form the control device consists oftwo spaced electrodes with an air gap therebetween and it ma be an ordinary spark plug.

Ih addition tothe control device, which Other features and advantages will appear from the following description and in the illustrative embodiment of the invention in the accompanying drawings, in which 1 is a fragmentary sectional elevatona view of an automatically controlled oi burning furnace showing the disposition of the control device and ignition means therein; and

Fi 2 is a diagr'ammaticalview showing the e ectrical connections for controlling the burner, an electrical ignition system and a control therefor.

Referring to these drawings: the auto--y matic oil burner may obviously Vbe of any suitable type and that shown herein is given solely by way of illustrative exam le. There are many other types which woul be equally suitable and with which my invention could as readily be used. As shown, the oil burner is of the centrifugal type and involves a cup atomizer 5 carried on the upper end of a hollow vertical shaft 6 through which oil is drawn up to the atomizer from a reservoir 7 by the action of centrifugal force. Shaft 6 is driven, as by spiral gears 8, from a horizontal shaft 9 connected to the armature of an electric motor 10. The latter the reservoir and theupporting casing for shaft 6 are shown as mounted on a common bed plate 11, one end of which extends into the ash pit 12 of furnace F. The fire box 13 has a central opening 14 in its bed'15 through whlch shaft 6 extends and through which combustion supporting air enters. The oil, in the form of a fine mist or 'spra is thrown outhorizontally from cu 5 an is adapted to be ignited from a spar plug 16, suitably su ported as shown.

e control device, which as stated may be a s ark plug, is shown in that form at 17A an includes an air gap 18 between two electrodes 19 and 20. The control device may be supported like the spark plug and I prefer to arrange vit as shown `at a distance therefrom.

The oil burner motor is arranged to be started and sto ped under thermostatic control, desirablygrom a room thermostat actin in any suitable manner tooperate a switc in the motor circuit. For convenience, the room thermostat and switchL have tact 30 which is stationaril been shown in conventional form at 21 and 22, respectively, in Fig. 2 and the switch is interposed in one of the

supply wires

23 and 24 leading from a suitable source of alternating current to the motor 10. Other usual safety devices, in common use ywith oil burners, may be interposed in the circuit to motor 10 and I have not attempted to illustrate more than the fundamental parts necessary to a proper understanding 4of this invention.

The ignition system comprises, in addition yto spark plug 16, a transformer T, of which 25 represents the core, 26 the primary, 27 thesecondary and 28 an auxiliary secondary for use-'in connection with the control device 17. The rimary winding 26 is connected in circuit with

L'the supply wires

23 and 24 but beyond the motor l-and'includes a switch, comprisin the contacts 29 and 30 .by means of whic the primary winding may be cut out of circuit without stopping motor 10. One terminal of the primary is connected directly to wire 23 and the other terminal is connected by a wire 31 to consupported, as from an insulating standar 32 from a bed plate 33. Contact 29 is mounted on a metallic lever 34, which is connected to wirel24 and is pivotally supported at one end, as from an insulating standard 35, also mountf ed on' bed 33. A- spring 36 urges lever 34 upwardly and tends to hold contacts 29 and engaged. The secondar`y27 is connected b wires 37 and 38 to the electrodes of spark p ug 16. It will be seen that there are two switches controlling the iprimary winding of4 -the transformer T and t us the high tension current to s ark plu 16` When switch 22 opens the ot er switc closes, as will appear, so that when the thermostat 21 causes switch 22 to close' and start the oil burner motor 10 it also causes the energization of the transformer and sparks are produced across the electrodes of plu 16 to ignite the oil. In the event of ignitlon, the contacts 29 and 30 are caused to se arate, as will appear, and cut out the rimary of the transformer, thereby stoppmg the ignition means.

The separation of contacts 29 and 30 is effected b electrical means adapted to be energized y current from the auxiliary sec- 'ondary 28, which current is permitted to.

flow, at least to an extent suflicient to perform the function, only when a degree of heat, such as that due to the llame from the oil burner, exists in the fire box. The lever 34 has attached thereto alu armature 39 which is adapted to be attracted by a solenoid 40, mounted on base 33. One terminal .of solenoid 40 is connected by a wire 41 to electrode 20 of the control lug 17' and the other terminal is connected by a wire 42 to one terminal of the auxiliary secondary 28. The other terminal of the latter is con i lows nected to the wire 37, to which the electrode 19 of the control plug is also connected. This wire 37 may be grounded, as indicated. On energization of solenoid 40 a quick, strong downward pull is imparted to lever 34 and thereby the contacts 29 and 3() are separated, which cuts out thc primary of the transformer and thus cuts off the current flowing 'to solenoid 40. To hold the switch lever 34 in its lower position, a second solcnoid 43 'is rovided which similarly acts on a second p unger 44 connected to lever 34. This solenoid -is bridged across the

suppl wires

23 and 24 and controlled by a switc i comprisinv two

contacts

45 and 46, which are normally o en but are adapted to be envaged by the grst downward movement of ever 34. The contact 45 is fixed to lever 34 and thus connected to wire 24. y Wire 23 is connected by a wire 47 to one terminal of solenoid 43 and the other terminal of the latter is connected b a wire 48 to contact 46. The latter is slida l mounted in a standard 49, insulated from tied 33, and is urged upwardly by a spring 50 to the limit permitted by a stop 51. The

contacts

45 and 46 do not quite touch so that the circuit to solenoid 43 is normally open but can be closed quickly, on the rst downward movement of lever 34. The solenoid 40 gives the ipick, strong pull necessary to cause a quie and sharp separation of contacts 29 and 30. The solenoid 43 then comes into play to hold the contacts separated, even after current ceases to/flow in solenoid 40, and solenoid 43 is so designed as to consume a veryA small amount of power, say five watts or t ereabouts. It can, therefore, be left in circuit for long in tervals with an exceedingly small expense for power. The solenoid 40, being used only intermittently and for intervals of short duration, can be wound to give the desired results and it matters little if more power is consumed. The solenoid 43 remains energized as long as the motor 10 continues to operate but as soon as the thermostat 21 opens switch 22 to stop the motor it also opens the circuit to solenoid 43. The spring 36 then restoresthe lever 34 and engages contacts 29 and 30. This action ensues 1mmediately 'after the current is cut off from motor 10 by the o ening of switch 22 and on again closing e latter the primary of transformer T 1s supplied with current as quickly as is motor 10. Consequently, the motor and ignition means start simultaneously and there can be no delay between the operation of these two elements. At the same time the control device causes the i ition means to be cut out immediately a r the burner is ignited. y

The o ration ma be summarized as folen the o' burner is not working the parts are in the relative positions illustrated in Fig. 2. The ignition means is liketical result is an intense wise idle and no current is being consumed thereby oi' by the switch holdin solenoid 43. As soon as operation of the oil ui'ner is required, as manifested b thermostat 21, switch 22 is closed by the atter. The motor 10 is thus started and oil is discharged into the tire box by the atoniizer. At the same time, the transformer is supplied with current and ignition s arks are produced at the spark plu 16. T ie spray of oil from the atomizer ollows the starting of the motor and is at least slightly deferred while thc sparks are produced at the plug simultaneously with the starting of the motor. Consequent] the ignition means is available an instant before it is needed.

By preference, the secondary 27 is designed to give a high voltage before the spark starts so as to insure its starting and, after the spark is jumpin at the plug, the current is such that the en s of the electrodes are brought to a glowing temperature. The result is virtually an arc, as distinguished from the ordinary jump s ark, and the praceat which is sufficient to gasify fuel oils of low volatility, whereby ignition of fuels, diliicult to ignite by a simple high tension s ark, is insured. The use of such an electrica ignition means, demands that the same be cut out immediatel that itis no longer needed to minimize estructiv" effects on the electrodes of the plug. There is thus an additional reason, over the ordinary reason of needless waste of ener for cutting out the ignition means prompt y.

VThis result is insured by the special control device which is arranged to respond only to the high temperature due to the oil burner flame. This device accomplishes its work instantaneously, or at least apparently so, and withprecision and certainty. The heat from the oil burner ame increases the conductivity of the air gap between the terminalsof the control plug and current ows to the solenoid to a degree sufiicient to impart a quick strong pull to armature 39. The contacts 29 and 30 are immediately separated, thereby openin the primary circuit of the transformer ang cutting out of action both the ignition secondary and the secondary used to supply the control plug. At the

same time contacts

45 and 46 are en aged to energize the solenoid 43 which holds the contacts 29 and 30 separated until the oil burner motor stops. At that time switch 22 opens and contacts 2Q and 30 immediately engage again, thus throwing the control of the i nition means back on the thermostat switc so that it will be instantly available when motor 10 is a ain started.

By analo it will be readily apparent to those skille in the art that the ignition controlling means may readily be adapted to operate a valve as well as the switch dislll) closed, whereby the control may have a field of service in connection with ignition means other than of an electrical character.

While in the precedin description the control device is describe as an air gap, it is recognized that the preferred form of the invention may be varied in numerous ways and still operate in essentially the same broad manner and upon the same broad principle. The air gap is the best example of a control device which when subjected to heat will Afunction in the manner above set forth but it is recognized that other control devices may he used in the same general manner, wherefore this invention is not to be restricted lo the particular form herein specifically set forth.

The invention turns largely on the particular control device as combined with other elements to effect the results disclosed. This device is the kry to the successful solution of the ignition control problem because it can be made as sensitive as need be and instantly responsive to the oil burner flame. It has been demonstrated that the heat from a lighted match held in proximity to the gap of the control plug will cause an immediate opening of, a switch by electrical means. The control device is thus the governing element in a broad combination with other elements of an ignition system. It follows that the details of such s stem and the particular types of the broa elements of the combination may be varied as desired and that the details disclosed are exemplary in character. It is the intention to claim the invention in the broadest possible legal manner.

What I claim is:

l. In combination, a burner, an ignition device therefor having an active condition for ignition of fuel from the burner and an inactive condition, means to automatically start and stop the burner and to. render the ignition device active simultaneously with the starting of the burner, means to render the ignition device inactive independently of the first named means, electrical means to operate the last named means, a source of electrical energy for said electrical means,

a control device associated` with the burner` and including twoterminals with an air gap therebetween, and a series circuit including said source, electrical means and terminals, said gap adapted to be heated by the burner flame and when so heated to permit suflicient current to How in said circuit to operate said electrical means.

2. ln combination, a burner, an ignition device there-for having an active condition for ignition of fuel from the burner and an inactive condition', means to automatically start and sto the burner and to render the ignition device active simultaneously with the starting of the burner, means to render the ignition device inactive independently of the first named means, electrical means to operate the last named means, a source of electrical energy for said electrical means, a control device associated with the burner Vand including two terminals with an air gap therebetween, and a circuit including said source, electrical means and terminals, said air gap adapted to be heated by the burner flame and when so heated to permit suicient current to flow in said circuit to operate said electrical means, and means operable by the first named means when it sto s the burner to reset the means whereby tlie ignition device was rendered inactive.

'3. In combination, a burner, automatic means to start and stop the same, electrical ignition means therefor includin an electrical circuit arranged to be c osed and opened by the starting and stopping, res vectively, of the burner under the contro of said automatic means, said circuit also including a normally closed switch, electrically operated means adapted when energized to open said switch, and a control device arranged in circuit with said electricall erated means and a suitable source o electricity, said device includin two spaced terminals with an air gap t erebetween and so located that said medium is heated by llame from the burner, said medium when so heated becoming conductive and permitting flow of` current across said terminals to energize said electrically operated means and open said switch to cut out said ignition means.

4. In combination, a burner, automatic means to start and stop the same, electrical ignition means therefor includin an electrical circuit arranged to be c osed and opened by the starting and stopping, respectively, of the burner under the control of said automatic means, said circuit also including a normally closed switch, electrically operated means adapted when energized to open said switch, a control device arranged 1n circuit with said electrically operated means and a suitable source of electricity, said device including two spaced terminals with an air gap therebetween and so located that said medium is heated by llame from the burner, said medium when so heated becoming conductive and ermitting liow of current across said termlnals to energize said electrically operated means and open said switch to cut out said ignition means, and means to hold said switch open until the burner is stopped by said automatic means and to then permit said switch to be closed.

5. In combination, a burner, spark elec- `trodes positioned Ato ignite the fuel from the burner, a transformer, .a secondary. circuit from the transformer including said electrodes, a primary clrcuit from the trans man Np. 1,630.70@

former including a self closing and normally closed switch therein, automatic means for starting and stopping the burner and for closing and opening said primary circuit, electrical means adapted w en energized to open said switch, a second set of spaced electrodes adjacent said burner, and a secondary circuit from said transformer including said electrical means and said second set of electrodes.

6. In combination, a burner, spark electrodes positioned to ignite the fuel from the burner, a transformer, a secondary circuit from the transformer including said electrodes, a rimary circuit from the transformer inc udin a selfclosing and normally Vclosed switch t erein, automaticlmeans for starting and stopping the burner and for closing and opening said primary circuit, electrical means adapted when energized to open said switch, a second set of spaced electrodes adjacent said burner, a secondary circuit from said transformer including said electrical means andsaid 'second set of electrodes, a second electrical means adapted when energized to hold said switch open, a supply clrcuit therefor controlled by said automatic means and ai switch in the last named circuit adapted to be closed by the opening of the first switch and opened by the closing of the latter.

7. The combination with an oil burner, an electric motor to-drive the same and a thermostat o rated switch to start and stop the motor, o Spark electrodes for igniting the oil from the burner, a transformer to produce sparks across the electrodes and connected in circuitwith said motor so as to be subject 'to control by said switch, a, self closingv switch also. in circuit with the transformer and adapted when opened to. cut out the transformer without stopping the motor, a second pair of spaced electrodes arranged adjacent the humor, electrical means ada ted when energized to 'pen the self closing switch, and4 acirqkmthe transformer ctnrirlarr or CORRECTION.

electric motor to drive the same and a thermostat operated switch to start and stop the motor, of spark electrodes for igniting the oil from the burner, a transformer to produce sparks across the electrodes and connected 1n circuit with said motor so as to be subject to control by said swltch, a self closingswitch also in circuit with the transformer and adapted when opened to cut out the transformer without stop ing the motor, a second pair of spaced e ectrodes arranged adjacent the burner, electrical means adapted when energized to open the self closing switch, and a circuit from the transformer including said electrical means and said second pair of electrodes, a second electrical means adapted when energized to hold the self closing switch open, a circuit from the motor circuit connected in shunt therewith and adapted to sup ly said second,` electrical means, and a switc 1n said shunt supply circuit adapted to be closed by the opening ofthe self closin switch.

9. In combination, a urner, means for startinr and stopping the same, an ignition device thaving' an active condition for igni tion of the fuel from the burner and an inactive condition, means for rendering said de vice active simultaneously with the starting of the burner, electrical means effective when energized to render 'said device inactive and a series electrical circuit including said elec trical means with an air gap and a source of high potential, whereby the air gap forms a reak in said circuit, said air gap bein subjected to the heat from the burner an when heated therely permitting a flow of current across sai gap to said electrical means.

In testimony whereof I have aiiixed my signature.'

HARRY C. HUBBELL.

Granted Maj' `3l, 1927, to

' HARRY c. HUBBELL.

It ie hereby certified that error appears in the printed specification of the eboye numbered p'etent requiring correction as follows: Page 4, line 5S, claim l, before ltlle word"'ap" insert the word "air"; page 5, line 86, claim 9,1before the word "said" inse-rt the word "energize"; and that the said Letters Petent should be read with these corrections therein that the same may conform te the record of the case in the Patent Office.`

Seel.

signed dialed um 21st da; of June, A.: n. 1921.

M. J. Moore, I Acting Commissioner of Patente.

man Np. 1,630.70@