US2375569A

US2375569A - Burner control apparatus

Info

Publication number: US2375569A
Application number: US419844A
Authority: US
Inventors: Lourdes V Mccarty
Original assignee: Milwaukee Gas Specialty Co
Current assignee: Milwaukee Gas Specialty Co
Priority date: 1941-04-25
Filing date: 1941-11-21
Publication date: 1945-05-08
Anticipated expiration: 1962-05-08

Description

y.. v. 4MGCARTY BURNER lCONTROL. APPARATUS yoriginal Filed April 25. 19:41

Mw,-1945.I

Patented May 8, 1945 i BURNER CONTROL APPARATUS Lourdes V. McCarty, Milwaukee, Wis., assgnor to Milwaukee Gas Specialty Company, Milwau# kee, Wis., a corporation of Wisconsin Original application. April 2 5, 1941, Serial No.

390,247. Divided and this application Novem- Vber 21, 1941, Serial No. 419,844

l1 Claims.

This invention relates, generally, to apparatus for controlling fluid iiow in conduits, and it has particular relation to an improvedv burner control apparatus of the character employing electromagnet means, an electrical operating circuit therefor, and a thermoelectric generator energized by the heat of a flame for supplying current to the operating circuit. k

The invention may be embodied in a wide variety of forms for controlling the supply of fuel to a wide variety of gas or other fuel burners.

For purposes of illustration, I shall refer to an illustrative embodiment of the invention, but it is to be understood that the invention is not limited to the particular embodiment herein set forth.

One of the main objects of the present invention is to provide in apparatus oflthe class described, a pair of electroresponsive valves or other electroresponsive control devices, for example an electroresponsive valve for the main burner and an electroresponsive valve for a pilot burner, the electroresponsive valves or control devices each including an electronriagnet, and there being a thermoelectric generator connected in circuit with the electromagnets for energizing the same by the heat of a flame on the thermoelectric generatorl in combination with means controlling the energization of one of the electromagnets, for example the electromagnet for the valve or control device for the main burner independently of -burner is actuated to open position as Well as the electromagnet for the other valve or control device.

One of the chief advantages of the combination set forth is that it provides for pilot control of valve means for both the main burner andthe pilot burnerand, at the same time, for condition responsive or other control, for example, of the main burner valveindependently of the valve for the pilot burner. This permits closing and opening the main burner valve by an automatic timer actuated switch, or a thermostatic or pressure actuated switch, or other condition responsive device, while/maintaining the pilot valve vopen as long as the thermoelectric generator is manual cooking or reset means for the valve for the main burner and the necessity of a manual held in open position through the instrumentality of the minute electromotive force generated by the heat of the pilot ame on the thermoelectric generator.

Another object of the invention is to provide mechanism of simple and improved construction which will operate effectively to accomplish the results set forth. A

While the particular structural features by which I obtain a device of the character set forth areimportant features within the more specic aspects of the invention, it is to be understood that the precise'features shown and described may be varied within the broader aspects 0f the invention. In order to acquaint those skilled in the art with the manner of constructing and operating a device in accordance with the present invention, I will now describe in connection with the accompanying drawings an illustrative embodiment of the invention. i

In the drawings: v

Figure 1 is a fragmentary and more or less diagrammatic view showing an embodiment of the invention in a pilot burner and main burner gas supply system;

Figure 2 is a vertical longitudinal section 'through the thermoelectric control and safety shutoff device shown in Figure l;

Figure 3 is a fragmentary vertical section taken on the line 3`3 of Figure 2;

Figure 4 is a fragmentary vertical transverse section taken on the line 4--4 of Figure 1; and

Figure 5 is a bottom plan view of the electrof magneticoperating unit taken substantially on the line 5--5 of Figure 2 and showing the valve member, its operating lever, and the hinge mounting for the operating lever.

' This application is a division of my priorrPatent N o. 2,349,443, issued May 23, 1944, on application Serial No. 390,247, filed April 25, I1941.

Referring now to the drawings, in Figure 1 the burner I0 is any suitable or preferred main burner. It may be the main burner for a room or space heater, or it may be the burner for a. water heater, or for a floor furnace, an oven burner,

one or more top burners for a gas range, or any other burner. A fuel supply pipe i I leads to the burner l0 for the delivery of gaseous or other fuel thereto-for example, through a mixing chamber I2 to which air is admitted in the usual cooking or resetting operation for thisvalve, and

to provide a thermoelectric control and safety/'- shutoif device in which the valve for the main way, as Well understood in the art.

Intel-posed in the fuel supply pipe i l is the thermoelectriccontrol and safety shutoff device indivice I is responsive to the pilot burner I6.

cated in its entirety at I5 in Figure 1. The de- It may also be responsive to a control Vdevice. I1 shown. for purposes of illustration in Figure 1, as a thermostatically actuated switch which, in the case of a hot water heater. may be subject to the temperature of the water in the tank, or, in the case of a room or space heater or iloor furnace, may be mounted in appropriate position within the room or other space heated by the burner I0. Instead of being in the form of a thermostatically actuated switch, the control device I1 may be of a character to operate, for example, upon the occurrence of an abnormal pressure in the tank of a hot water heater, or upon the-.occurrence of any other abnormal, defective or insufficient functioning of the apparatus. The room or space in which the control device il is located is indicated more or less diagrammatically by dot and dash lines i8 in Figure 1.

The pilot burner I5, which is located in juxtaposition to the main burner lll to maintain a pilot name for igniting the main burner, is supplied with gaseous fuel by a pilot supply pipe I9 which is shown as leading from the housing or case of the thermoelectric control and safety shutoff device I5. This may vary Within the scope of the present invention.

Referring now in detail to the thermoelectric control and safety shutoff device I5, thehousing or case 22 for this device has an inlet at 23 and an outlet at 24. The inlet 23 opens into the interior of the housing, and a partition or wall 25 separates the interior of the housing from the outlet 2d. The partition 25 has an opening into which is threaded a retaining ring 2B which secures a valve seat member 2l in place. The valve seat member 2l defines an opening 28 -for placing the interior of the housing 22 in communication with the outlet 24. The upper end of the valve seat member 2l is provided with an annular valve seat 29 `upon which the shut-oli valve disc 30 is adapted to seat to shut oi thesupply of fuel to the burner I Il. A gasket may be provided at 3 i.

Contiguous sections of the fuel supply pipe il are connected to the inlet at 23 and to the outlet at 24 as shown in Figure l. A cover 34 is removably secured upon and closes the top of the housing 22. The cover 34 is shown as secured to the housing A22 by screws 35, and a cover gasket may be provided at 35.

The electromagnetic operator for the valve or controlling member, andthe valve, valve lever,

and energy storing means constitutes. unitary assembly which is carried by the cover 84, preferably resiliently, as will 'hereinafter appear. This assembly is enclosed within the housing 22 when the cover 34 is applied and is removable from the housing by removing the cover.

The electromagnetic operator includes an electromagnet consisting of a magnet frame 40 shown as of generally U-shaped form, although this may vary. 'I'he coil 4I is shown as `wound around one leg of the magnet frame,- andthe end of the other leg of themagnet frame is shown as turned at" 42 to position generally, parallel to the armature 43 to present a relatively large pole face to the armature.

The ends of the magnet frame 40 extend through openings in a sealing plate 44, the margin or which is turned or flanged laterally to receive a sealing cover 45 between which and the -plate v44 the pole faces of the magnet frame 40, the armature 43, and the energy storing means are enclosed and sealed. 'I'he armature 43 is til byacliaphragm pin t5.

hinged by hinge means 48 to a spacer 50 iixed to or integral with the sealing plate 44. The hinge means 43 hinges the armature 43 in position adjacent the pole faces of the magnet frame, and the hinge means 48 is preferably of Spring character to maintain the armature in the desired position. 'I'he cover 45 is removably secured to the sealing plate, for example by screw 52, and the cover, when in place, may limit movement of the armature away from the electromagnet.

The magnet frame 40 is mounted on and car-v ried by a mounting plate 56 which has a downturned lug 5l positioned against the back of the downturned end 42 of the magnet frame. Screws (not shown) secure the sealing plate M to the downturned lug 5l on the ,mounting plate 56. A sealing gasket is preferably provided at 59.

The armature 43 and the downturned end 62 of the magnet frame have registering openings 62. A plunger 63, movable endwise in these openings, is secured to the center of a flexible diaphragm The diaphragm Bl is clamped in place to the back of the downturned lug 5l on the mounting plate 5t by a retaining plate 6B which may be secured in place by screws and cooperating nuts (not shown), or otherwise as desired. The retaining plate il@ and the downturned lug 5l on the mounting plate 565 have registering openings. and the diaphragm Sli seals the space between the sealing plate llfl and the cover 45 against the entry of deleterious matter through the openings 62.

A valve or controlling member operating lever l0 s hinged in asuitable manner at 'iii by a pair of hinge springs i3 to lugs on the sealing plate fifi at opposite sides of the lever, or to lugs on a mounting lplate secured in place with the sealing plate. The opposite ends of the hinge springs "it are secured, for example, at lll, to lateral lugs (not shown) on the operating lever lt. The lever l@ has a lug 'i6 offset upwardly therefrom, and the valve disc member 3@ or controlling member is'secured to this lug it by a valve disc screw it. The outer end of the lug llt engages in a slot i9 in the downturned lug till on the mounting plate 55.

`Engagement of the outer end of the lug 'it with the lug 80 at the bottom of the slot 'lil serves to prevent undue separation of the valve disc 3U from the mounting plate 56 and electromagnetic operator assembly, particularly when the assembly is removed from the housing 22.

At its opposite end the lever 'It is provided centrally between its-opposite sides with a downwardly offset lug t2 having a pointed end for engagement at 83 with the adjacent end of the diaphragm pin t5. The lever l, being hinged or fulcrumed close to the pointed engagement at Q83 with the plunger 63, provides for imparting relatively great movement to the valve disc 30 with relatively slight movement of the plunger 33. The mounting plate lifi has an opening 85, and a relatively light coiled spring @il is disposed 'to extend through this opening and between the magnet frame 40 and the lever l@ for returning the -valvedisc 39 to closed position upon deenergization ofthe electromagnet. The thermoelectric control and safety shutoil device is preferably positioned vertically in use, as shown in Figures 1 and 2, in which case I contemplate returning the valve disc 30 to closed position by gravity and without the use of a spline, such as the spring 86, or by gravity in conjunction with the spring 86, or otherwise as desired. A circular raised portion 81 on the lever 10 engages in the the armature 03;

lower end convolution of the spring 38 for holding the lower end of the spring in place and against lateral displacement.

It will be noted that the gas pressure within the housing 22 acting upon the top-of the valve disc 30 holds the valve disc to its seat 29. When thel valve is closed it requires the greatest force to lift it or move it from its seat 29, and as the valve disc 30 is lifted' or moved away from its seat, the drop in pressure across the valve causes a rapid drop in the force required to continue movement of the valve disc 30 to full open position.

The energy storing means is shown as comprisinga pair of iiat leaf springs 90 and 92 normally disposed in substantially parallel relation. The upper ends of these leaf springs 90 and 92 are attached to the armature 43, for example, by a screw 93 threaded into an armature bushing 94, which bushing 94 in turn is suitably secured or iixed to Spacers are provided at 95, one between the armature 43 and the spring 90 and the other between the spring 90 and the spring 92. A retaining clamp 96 is provided be'- tween the spring 92 and the head of the screw 93. An adjusting pressure screw l98, threaded through the spring 90 near its lower end, has endwise engagement with the plunger 63 preferably spaced from or out of contact with the spring 90, as shown more or less diagrammatically in Figure 2. The sc rews 98 and |00 are adjustable to adjust the action of the'device and may be locked in adjusted positions as desired, tension clamps being indicated more or less diagrammatically at |02 and |03 respectively. The spring 92 has an opening |04 which operates over the head of the screw '98 to permit-movement of the spring 92 toward the spring 90 and free ofthe spring 90 in the initial movement of the armature to attracted position.

By reference to Figure 3 it will be seen that the pilot'valve member 200, which` is adapted to shut oli or control the supply of fuel to the pilot burner,l is urged toward itsseat and toward a closed position by a coiled spring 20|'. The valve member 200 'will be in open position only when the pilot light is burning, and, when in open position, the fuel for the pilot gburner passes from the housing 22 through an opening 202y and thence through the opening dened by the valve seat member and through openings 203 and an outlet 204 into the pilot supply pipe I9 leading to the pilot burner I6.

The cover 34 has a boss provided with a bore 206. A magnet support 201 and a lever support 208 are clamped in place in the inner end of the bore 206 by'a generally cup-shaped member 2|0 threaded at its inner end into the outer end of the bore 206. A exible diaphragm 2|2 clamped in place marginally between the

members

201 and 208 carries a diaphragm pin 2|4. A dowel pin Imay be provided at 2|5. A lever 2l6 is ful-` crumed at 2|1 on the lever support 208 and has one end positioned to be actuated by the diaphragm pin 2| 4, and its other end is positioned to actuate the plungeror stem 220 for the vvalve member 200.

An electromagnet is housed-within the member 2l0 and comprises a magnet frame 22|, shown of generally U-shaped form, and an energizing coil The magnet frame 22| is attached by a sleeve member 223 to the center of the raised bottom portion of thernagnet support 201. An armature stem 224 passes slidingly through the sleeve 223, and has an armature 226 mounted on its outer end, preferably with suiicient looseness or play to enable the armature to accommodate itself to the pole faces of the magnet frame when in attracted position. The inner end of the armature stem 224 contacts the diaphragm pin 2|4.

A flexible diaphragm 230 is secured marginally in the outer end of the member 2|0 by a retainer ring 232, and a reset button 234 is secured at 235 to the center of the diaphragm 230. The reset button projects slidingly through an opening 236 in the outer end oi the member 2|0. When the button 230 is engaged by the finger and pressed inwardly,jit moves the armature 226 to attracted position, and the accompanying inward move' ment of the stem 220 swings the lever 2i6 in a clockwise direction about its fulcrum 2 i1, the enpilot flame for supplying thermoelectric current to the thermoelectric operating circuit for energizing the electromagnetfor the main burner valve as well as the electromagnet for the pilot burner valve, is shown more or less diagrammatically as a thermopile l5 comprising a plurality of thermocouples-three being. shown-connected in series, This, of course, may vary within thev scope' of the present invention, any thermoelectric generator which willgenerate the required tion to state that each of the three thermocouples of the thermoelectric generator M3 comprises the usual or any suitable elements El i0 and i i1 of different thermoelectric characteristics, each pair of said elements 4being joined at Md to provide the hot junctions which are placed in position to be heated by the pilot flame as long as the pilot flame is burning. Any other suitable thermoelectric or electric generator may be employed.

The lead conductors for the thermoelectric generator may be of the type more fully disclosed in Oscar J. Leiris Patent No. 2,126,564, granted August 9, 1938, or the construction oi the thermo'- electric leads may be of any other suitable or preferred form.

For the purpose of this description sufce itK to state that the thermoelectric lead conductors may comprise, as shown fragmentarily in Figure 4, an inner lead conductor4 |25and an outer tubular lead conductor. 622 surrounding the inner lead conductor. The inner lead conductor is insulated from the outer lead conductor, for instance, by a wrapping of insulation |21 on the inner lead conductor. One terminal of the therrnoelectric generator is shown more or less diagrammatically and safety shutoff device and the ends oi the leads |25 and |26 opposite the ends which are connected to the thermoelectric generator. This removable lead connection may be of any suitable form. Suiilce it, for purposes of this description, to state that the inner lead |25 has a connector cone |25a which seats in the correspondingly recessed outer end of the terminal tip |25b, and is clamped in contact therewith by' a connector sleeve |32. The adjacent end ol' the outer tubular lead conductor |26 is grounded to the cover 34 of the housing through a bushing |33 and theconnector sleeve |32 to the internally tn readed boss |34 on the cover 34.

AOne end of the coil 4| (liigure 2) is secured to the under side of the cover 34 by a binding screw |40, and thereby is vrgrounded to the coverl and thus connected to the outer lead conductor |26. The other end |42 of the coil 4| is con- 4 nected to a terminal post M3 fixed in a boss i 44 on the cover lit and insulated therefrom by a terminal bushing i115. The terminal tip |b, which is insulated from the cover by an insulator bushing |48,'is connected in circuit with a second terminal post by a connector strip |52. An insulator strip is provided at |53. (Figure 4). The terminal post |50 is fixed .in a boss |55 on the cover 34 and is insulated therefrom by a terminal insulator |56. An insulating terminal board |59 is mounted across the tops of the bosses |44 and |55, suitable washers being provided at |59 and the upper ends oi' the terminal posts |43 and |50 being peened over `or otherwise formed to secure the terminal board in place.

Where a thermostat or other condition responsivc device is employed as indicated at I1 in Figure 1. the leads |62 and |63 for this device are connected to the terminal posts |43 and |50 by suit-` able binding screws |65. The thermostat or other condition responsive device I1 is thus placed in series circuit relation with the thermoelectric generator and the coil 4| of the electromagnet for the main valve.

To secure accurate positioning of the valve disc 30 or other controlling member with respect to the valve seat 29 or cooperating part, and independently, for example, of the attachment of the coverA 34 to the housing 22, I provide a resilient mounting for the electromagnetic operator assembly.

This resilient mounting comprises vertically elonlin the mounting plate. The upper endsl of the screws or posts |15 have threaded engagement (not shown) with the cover 34, and springs |10 are coiled about the-respective posts and interposed between the cover 34 and the mounting plate 56. When the cover- 34 is applied, the electromagnetic operator is positioned within the housing 22 and the mounting plate 56 yseats `upon horizontal seating surfaces, one'of which is indicated at |80, in the interior of the housing 22, thus assuring accurate positioning of the valve disc with respect to its valve seat 29; as is disclosed more fully in my copending application Serial No. 390,247,.above mentioned. The cover 34 may be clamped in place, and any improper fit of the cover or nonuniiormity in the clamping of the same in place will not disturb the proper positioning of the valve disc 30. The heads and the lower ends of the screws or posts |15 are spaced below the mounting plate 56 and are positioned in recesses |92 in the housing 22.

The magnet frames and armatures are preferably iormed on an alloy of relatively low magnetic reluctance, and the operating circuit for the device is'preferably of low Iresistance characteristics. p The energizing coil 222 for the pilot valve electromagnet is preferably connected in parallel circuit relation with the electromagnet for opening the main valve and for holding same open. This permits the thermostat or other condition responsive device at I1, for example, to operate to deenergize the electromagnet for the main valve without deenergizing4 the eleotromagnet for the pilot valve. When the pilot light is extinguished, both the main valve and the pilot valve operate to closed position. The spring 20| closes the valve 200 when the electromagnet therefor is deenergized, and through the stem or plunger 220, lever 2 I6, diaphragm pin 2 I4, and armature stem 224 moves the armature to retracted position and the reset button to its outwardly projected position as shown in Figure 3. When the reset button is pressed inwardly in resetting or coclzing the device, the armature is moved to attracted position, and assuming that the electromagnet for the pilot valve is sufiiciently energized by the heat o f the pilot flame on the thermoelectric generator, the armature will be held magnetically in ettracted position, thus holding the pilot valve open as long as the pilot light is burning.

As thus described, the pilot generator shown, for example, at I5 in Figure 1, supplies the thermoelectric current for energizing the electromagnet for the pilot valve as well'as the thermoelectric current for energizing the electromagnet for the main valve.

i The operation of the device is as follows:

Assume that the pilot light is lighted and heating the hot junctions ||8 of the thermoelectric generator to supply the operating thermoelectric current to the circuit for energizing the two electromagnets, and that the thermostatV or other condition responsive device at has operated to open or disable the thermoelectric circuit to deenergize the electromagnet for the main burner valve. 'The armature 43 is then positioned in retracted position with an air gap between it and the magnet frame by the screw 98 and plunger 63 pushing against the diaphragm pin 65 and point 63 on the valve lever 10, the armature and energy storing springs and 92 being positioned substantially as shown in Figure 2. The main valve \disc 30 will be closed upon its seat 29 to shut off the supply of fuel to the main burner, and will 55 be held closed by the pressure of the gas within the housing 22.

Now, when the thermostat or other condition responsive device closes or enables the thermoelectric circuit for the main burner valve electromagnet, the thermoelectric generator will supply thermoelectric current for energizing that electromagnet.

When thev main burner valve yelectromagnet', is energized, the armature 43' is pulled toward the pole faces of the magnet frame by the magnetic attraction. The lower end of the energy storing spring 90is held against following the armature by engagement of the adjusting pressure screw 98 with the plunger 63 which, in turn, is prevented from moving by the gas pressure acting on the valve disc 30, said lvalve disc being operatively connected to the spring 90 by means of the adjusting screw 98, plunger 63, point 83, pivot point .12, and lever 10. As a result, the spring 90 is tensioned by a scissors-like action or llame will energize the electro-magnet for the main burner valve whereupon, assuming that pole faces of the magnet frame and after linitial tensioning of the spring 90, the pressure adjusting screw |00, carried by the spring 92 contacts the spring 90. Further movement of the armal ture 43 toward attracted position thereupon further tensions the spring 90 and. at the same time, tensions or storesup energy in the second spring 92. At the time when the movement of the armature 4 3 to attracted position is tensioning only the spring 9D, the magnetic attraction is least, and when the movement of the armature yis tensioniig both springs 90 and 92, the armature is closer to the magnet frame and the magnetic attraction is greater. The tension in the leaf springs 90 and 92 is built up or energy is stored until the combined tension or energy in both springs is sufficient to lift or open the valve disc 3!! p against the gas pressure, whereupon the stored energy operates to open the valve quickly and eiectively to set up the supply of fuel yto the burner lll. .As the valve disc 30 begins to lift or open, the pressure across it drops and leaf spring 9D continues to lift the valve and moves away from the spring QZ-that is, the point of the pressure screw |00 loses contactwith the spring Sti.

The position of the armature 43 when the valve disc 3011s being lifted depends upon the gas pressure across the disc--that is, the greater the gas pressure the further the armature moves toward the pole faces of the magnet frame before the valve disc begins to open. The force or energy in the leaf springs 90 and 92 must exceed the combined force of the gas pressure and other counteracting forces before the valve disc 3b can be opened. It should be borne in mind that neither spring Sii nor 92 is stressed when the valve disc 3l) is in the closed position-that is,` on the valve seat. The spring St is slightly stressed when the valve disc is in the open position. This is caused by the pressure drop across the valve, the Weight of the valve, and vthe force of spring the thermoelectric circuit for this valve is closed, the valve will be automatically operated to open position in the manner already described. -The pilot burner valve selected for illustration requlres manual resetting of the same to open position, but the use of a pilot burner valve which will open automatically is contemplated.

' I have determined,.by experiment,- that in one preferred embodiment of the invention the ratio of the air gap with the armature in retracted position to the length of air gap with the armature in attracted position is preferably approximately over three times the ratio of pull with the armature in attracted position to the pull with the armature in retracted position.

The embodiment of the invention shown in. the drawings is for illustrative purposes only, and it is to be expressly understood that said drawings an'd the accompanying specification are not to be construed as a 'deiriition of the limits'or scope of the invention, reference being had to the appended claims for that purpose.

r1, I claim: l. In burner control apparatus, in combination, a main burner, a pilot burner positioned to light said main burner, a fuel supply line leading to the main burner, a fuel supply line leading to the pilot burner, a main burner shutoi valve in the fuel supply ,y line leading tothe main burner, a firstelectromagnet, an electroresponsive-shutoff valve in the fuel supply line leading to the pilot burner, a second electromagnet adapted when energized to hold said pilot valve open, a thermoelectric generator positioned -to be heated by the pilot burner and connected Iirl circuit with said first and. second electromagnets to energize the same by the heat of the pilot burner on lsaid thermoelectric generator, and mechanical connections between said first electromagnet and said main burner shuto' valve whereby said rstl electromagnet, when energized llt. However, spring 92 is not tensioned at this g time because the point of the screw Gilt is not in Contact with the spring Sti. The energy storing means presents to the armature in all positions thereof in its movement to attracted position a' resistance less than the magnetic attraction between the electromagnet and the'armature at the corresponding position of the' armature, and therefore the energy storing means does not prevent or obstruct movement of the armature to attracted position.

From the foregoing it lwill be apparent that as long as the thermoelectric generator is heated by the pilot llame, the main valve will be opened and closed'automatically by the condition responsive or equivalent means.

If, for any reason, the pilot burnerl is `extin-` by said thermoelectric generator, opens said main burner valve and holds it open 2. In burner control apparatus, in combination, a main burner, a pilot burner positioned to light said main burner, a fuel supply line leading to the main burner, a fuel Asupply line leading to the pilot burner, a main burner shutoff valve in the fuel supply line leading to the main burner, a first electromagnet, an electroresponsive shutoff valve in the fuel supply line leading to the pilot burner; a second electromagnet adapted when energized to hold said pilot valve open, a

electric generator, mechanical connections between saidl first electromagnet and said main burner shutoff valve whereby said 'first electromagnet, when energized by said thermoelectric generator, opens saidv main burner valve andv holds itv open, automatically operable switch means connected into the thermoelectric circuit including saidthermoelectric generator and said rst electromagnet for automatically opening v and closing said thermoelectric circuit, and

' and ahead of said automatically operable switch means for energization of said second electromagnet by the heatr of the pilot burner on the Non.

said automatically operable switch means.

3. In burner control apparatus, in combination, a main burner, a pilot burner positioned to light said main burner, a fuel supply line leading to the main burner, a fuel supply line leading to the pilot burner, a main burner shutoff valve in the fuel supply line leading to the mainy burner, a first-electromagnet, an electroresponsive shuto valve in the fuel supply line leading to the pilot burner, a second electromagnet adapted when energized to hold said pilot valve open, a thermoelectric generator positioned to be heated by the pilot burner and connected in circuit with said iirst and second electromagnets to energize the same by Athe heat of the pilot burner on said thermoelectric generator, and means supplementary to and operating in conjunction with said first electromagnet and the thermoelectric generator to open the main burner shutoff valve upon energization of the thermoelectric generator by the heat of the pilot burner on said thermoelectric generator and independently of the pressure of the fuel in said main burner fuel supply line.

4. In burner control apparatus, in combination, a main burner, a pilot burner positioned to light said main burner, a fuel supply line leading to the main burner, a fuel supply line leading to the pilot burner, a main burner shutoff` valve in the fuel supply line leading to the main burner, a rst electromagnet. an armature for said electromagnet having an attracted position and a retracted position, an electroresponsive shutoff valve in the fuel supply line leading to the pilot burner, a second electromagnet adapted when energized to hold said pilot valve open, a thermoelectric generator positioned to be heated by the pilot burner and connected in circuit with said first and second electromagnets to energize the same by the heat of the pilot burner on said thermoelectric generator, energy storing means whereby movement of the armay ture to attracted position stores energy for opening said main valve, and operating connections between said energy storing means and said main shutoff valve effective for moving said main shutoff valve to open position by the energy stored in said energy storing means as the armature approaches its attracted position.

5. In burner control means, in combination, a main burner, a pilot burner positioned to light said-main burner, a fuel supply line leading to the main burner, a fuel supply line leading to the pilot burner, a main burner shutoff valve, means for operating said valve comprising a first electromagnet, a pilot bur-ner shutoff valve, means for operating said pilot valve comprising a second electromagnet, and a thermoelectric generator positioned to be heated by the pilot burner and connected in circuit with said first and second electromagnets to energize the same bythe heat of the pilot burner on said thermoelectric generator, the operating means for both of said valves being closed against escape of fuel to the atmosphere and effective for holding the respective valves open when the respective electromagnets .are energized by said thermoelectric generator. l

6. In burner control means, in combination, a main burner, a pilot burner positioned to light said main burner, a fuel supply line leading to the main burner, a fuel supply line leading to the pilot burner, a main burner shutoff valve, means for operating said valveV comprising a first thermoelectric'generator and independently of electromagnet, a pilot burner shutoff valve. means for operating said pilot valve comprising a second electromagnet, a thermoelectric generator positioned to be heated by the pilot burner and connected in circuit with said first and second electromagnets toenergize the same by the heat of the pilot burner on said thermoelectric generator, the operating means for both of said valves being closed against escape vof fuel tothe atmosphere and effective for holding the respective valves open when the respective electromagnets are energized by said thermoelectric generator, automatically operable switch means in the thermoelectric circuit including said thermoelectric generator and said. first electromagnet for automatically opening and closing saidther- `xnoelectric circuit, and means connecting said second electromagnet in parallel circuit relation with the thermoelectric circuit including said thermoelectric generator and ahead of said automatically operable switch means for energization of said second electromagnet by the heat oi' the pilot burner on the thermoelectric generator and independently of said automatically operable switch means.

7. In burner control apparatus, a main burner, a pilot burner positioned to light said main burner, a fuel supply line leading to the main burner, a fuel supply line leading to the pilot burner, a pair of electroresponsive devices respectively controlling said fuel supply lines each comprising a valve and an electromagnet having mechanical operating connection to the valve and effective when energized for holding it in open position, a thermoelectric generator adapted to be heated by said pilot burner and connected in circuit with both of said electromagnets for energizing the same, and means for controlling the energization of one of said electromagnets independently of the other thereof.

8. In burner control apparatus, a main burner, a pilot burner positioned to light said main burner, a fuel supply line leading to the main burner, a fuel supply line leading to the pilot burner, a pair of electroresponsive devices respectively controlling said fuel supply lines each comprising a valve and an electromagnet having mechanical operating connection to the valve and eifectivawhen energized for holding it in open position,`a thermoelectric generator adapted to be heated by said pilot burner and connected in circuit with both of said electromagnets for enerv gizing the same, and condition responsive means for opening and closing the circuit connection between said thermoelectric generator and one of said electromagnets independently of the circuit connection between said thermoelectric generator and the other of said electromagnets.

9. In burner control apparatus, in combination; a main burner, a pilot burner positioned to light said main burner, a fuel supply line leading to the main burner, a fuel supply line leading to the pilot burner, a main burner shutoff, valve in the'fuel supply line leading to the main burner,

electric generator opens said main burner valve and holds it open.

10. In burner control apparatus, in combination, a main burner, a pilot burner positioned to light said main burner, a fuel supply line leading to the main burner, a fuel supply line leading to the pilot burner, a mainburner shutoff valve in the fuel supply line leading to the main burner, a first electromagnet, an electroresponsive shutoffvvalve in the fuel supply line leading to the pilot burner, a second electromagnet adapted when energized to hold said pilot valve open, a thermoelectric generator adapted to be heated by said pilot burner and connected in circuit with said first and second electromagnets for energizing said electromagnets, mechanical connections between said flrst electromagnet and said main burner shutoff valve whereby said first electromagnet when energized by said thermoelectric generator opens said main burner valve and holds it open, and condition responsive means controlling the energization of the electromagnet for the main burner shutoff valve independently of the energization of the electromagnet for said pilot valve.

11. A fuel burner control apparatus comprising a main burner and a fuel supply pipe therefor, a pilot burner in juxtaposition to said main burner, a main burner valve, a pilot burner valve, an electromagnetic operator having mechanical connection to said main burner valve for operating the latterto'open position and for holding same in open position, electromagnetic means effective when energized for holding the pilot burner valve open, means for resetting said pilot burner valve, and thermoelectric generator means adapted to be heated by said pilot burner and connected in circuit with the electromagnetic operator for the main valve and in circuit with the electromagnetic holding means for the pilot valve for energizing said electromagnetic operator and said electromagnetic holding means.

LOURDES V. MCCARTY.