US2507006A

US2507006A - Oil burner of the spinner type

Info

Publication number: US2507006A
Application number: US746506A
Authority: US
Inventors: Kemper M Hammell; Robert R Witherell
Original assignee: EUREKA WILLIAMS CORP
Current assignee: EUREKA WILLIAMS Corp
Priority date: 1947-05-07
Filing date: 1947-05-07
Publication date: 1950-05-09
Anticipated expiration: 1967-05-09

Description

y 9, 1950 K. M. HAMMELL ET AL 2,507,006

OIL BURNER OF THE SPINNER TYPE Filed May '7, 1947 3 Sheets-Sheet 1 1N VEN TOR5. E- l. W

y 9, 5 K. M. HAMMELL ET AL 2,507,006

OIL BURNER OF THE SPINNER TYPE Filed May 7, 1947 3 Sheets-Sheet 2 29 ff JI ENTORa 8/21 67' I 4/17/7 25 255 i /4 z2 aeZZ -ZZZI May 9, 1950 K. M. HAMMELL ETAL OIL BURNER OF THE SPINNER TYPE 5 Sheets-Sheet 5 Filed May 7, 1947 kwpef M Patented May 9, 1950 OIL BURNER OF THE SPINNER TYPE Kemper M. Hammell and Robert R. Witherell, Bloomington, Ill., assignors to Eureka Williams Corporation, Detroit, Mich, a corporation of Michigan Application May '7, 1947, Serial No. 746,506

Claims.

This invention relates to oil burners and has particular relation to spinner type oil burners of relatively low fuel burning capacity.

Heretofore oil burners of the spinner type have been designed only to furnish heat for houses of relatively large sizes, this being the practice merely because such oil burners were comparatively complicated in design and large in size and consequently the expense involved in their construction was such that they could not be sold at a fairly low price. It was therefore necessary to design these oil burners in relatively large capacities because it was only where a burner of such size and capacity was required that such burners could be sold.

It is the purpose of this invention to simplify the design of such spinner type burners and to change the method of forming the inflammable mixture in such manner that the flame from the burner will be somewhat conical in formation and consequently can be used in a combustion chamber of considerably smaller size than heretofore has been required. With such types flame it will not be necessary to install metallic rings or other means around the outer wall of the combustion chamber for catching the particles of oil which may pass through the flame and be discharged radially outwardly therefrom. With the structure described these particles either will remain in the conically shaped combustible mass and will be burned along with other perhaps more finely atomized particles or they will be recirculated and atomized to a greater extent in the spinner head before being discharged into the combustible mass.

It is also the purpose of the invention to provide a new and improved spinner head for the burner in which the fuel will be completely atomized in the primary air of the burner prior to the delivery of any of the mixture to the region where it will be mixed with the main body of secondary air employed to support combustion of the burner flame. This feature employs a burner head which recirculates within the spinner head any particle of oil not sufliciently atomized to remain in suspension within the primary mixture prior to the entrainment of the latter within the secondary air stream.

Other and further objects of the invention will be apparent from the following specification taken in conjunction with the accompanying drawings of which there are three sheets and wherein:

Fig. 1 illustrates a vertical cross sectional view through an oil burner embracing the features of the invention here disclosed;

Fig. 2 is a horizontal cross sectional view taken through the burner in two planes substantially along the line 22 in Fig. 1;

Fig. 3 is an enlarged fragmentary view of the fuel metering pump disclosed in vertical section by Fig. 1;

Fig. 4 is a view similar to that shown by Fig. 3, except that Fig. 4 illustrates a modified form of fuel metering pump;

Fig. 5 is a fragmentary side elevational view of the burner ignition device as the latter might be seen looking at the plane of line 55 in Fig. 1;

Fig. 6 is a diagrammatical illustration of the oil burner illustrated by the preceding figures and of the electrical control system employed in its operation; and

Fig. 7 is a view similar to Fig. 6 except that Fig. 7 illustrates a modified form of control system for operating said burner.

Referring to Fig. 1, there is disclosed at the upper portion of the drawing a metallic support or combustion chamber wall It] having a cylindrical opening formed therein by a laterally projecting annular flange II. The support or wall it may form the lower wall of the combustion chamber in which the burner is employed, if desired.

Secured to the outer end portion of the flange H is a cylindrical flange portion l2 of a cylindrical casing l3 of the burner 15. Beneath the flange portion l2 the casing I3 is tapered inwardly as indicated at I 4 to provide a region within the casing of expanding area.

Disposed within an intermediate portion of the casing I3 is a plurality of longitudinally disposed fins or supports l6, these being disposed in spaced relation circumferentially around the casing and projecting radially inwardly therefrom. Located internally with respect to these fins and secured to and supported upon the inner extremities thereof is an electrical motor ll comprising a motor casing I8, a stator l9 and a rotor 24. The rotor 2| is supported within the stator upon a centrally disposed shaft 22 which is mounted for rotation within the motor casing it upon self-aligning

bearings

23 and 24. The shaft 22 extends coaxially within the casing It a considerable distance beyond each of the ends of the motor [1.

Secured upon the end of the motor l! remote from the wall it is a fuel metering pump 26 com prising a pair of oppositely disposed end blocks 2*] and 28 each secured upon gaskets as against the opposite edges of cylinder block St. The cylinder block 3! has a concentric opening formed therein in an enlarged portion at one end of which is located an eccentrically disposed cylinder ring 33. Disposed in spaced relation internally of the cylinder ring 33 is a concentrically formed rotor 3 an end portion 36 of which is provided with a finished surface adapted operativel to engage and to provide a running fluid tight fit against the adjacent end of the end block 28. The rotor 34 has a threaded end 31 projecting therefrom which is secured within a threaded opening formed concentrically in the adjacent end of the shaft 22. A sealing ring 38 is disposed around the end of shaft 22 in such manner as to operatively engage the end block 21 to prevent leakage of fluid from the opening 32. Formed radially inwardly of the rotor 34 is a cylindrical opening or metering pump cylinder 33, the inner extremit of which is connected to a transversely disposed port z-l arranged within the rotor 35 remotely with respect to the center of rotation thereof.

Disposed within the cylinder 39 is a piston 42, the outer extremity of which is enlarged as is indicated at 45 to provide a portion having considerable mass, to be affected by centrifugal force resulting from the rotation of the rotor 34 to move the piston 42 inwardly and outwardly with respect to the cylinder 39 when the rotor 34 is rotated by the shaft 22 The enlarged end 4-5 of the piston 42 will be so held in engagement with the inner eccentrically disposed surface of the cylinder ring 33 that it will follow the surface of the ringforso actuating the piston.

The end block 26 is provided with two sets of ports indicated at 43 and at, the port 43 being disposed in such position as to communicate with the port during a portion of each revolution of the rotor 34, while the port 46 communicates with port 4i during a different portion of each revolution of the rotor 34. Port 43. also communicates with a fuel supply conduit indicated at 46, while 44 likewise communicates with an oil supply conduit 47. formed concentrically with respect to.

both the rotor 34 and the shaft 22 It Will be apparent that'the rotation of the ro-- tor 3.4 by the motor El will cause the pistons, 42 to pump metered quantities of oilfrom the sup.- ply conduit 58 into the supply conduit 41.

The structure disclosed by Fig 4 is similar to that disclosed by Fig. 3iexcept that in Fig. 4 the rotor 3% is permanently magnetized in the metallic portions thereof immediately adjacent the cylinder 39 and the. port 4i. Also. a piston 242 is employed in the cylindertfi which is likewise magnetized to provide. a permanent magnet and the piston 242 further differs from the pi ton 42 in the respect that piston 242 is uniform in cross section from end to end.

It will be apparent that if the piston is polarized oppositely with respect. to. the adjacent portions of the rotor 34, the piston 242 will tend to be expelled from the cylinder so that the outer end thereof will always tend to remain in sliding contact with the inner eccentric surface of the cylinder ring 33 during the rotational movement of the rotor 34.

At the end of the motor I S opposite the metering pump 26 there is secured from the shaft 22 a fan 68, the angularly disposed blades or vanes 49- of which are arranged in such manner as to deliver an annular blast of air in a direction away from the motor IT. The air supplied to the fan 48 is drawn across the fins 56 extending around the motor I! from the vicinity of the metering pump 26 where it is admitted to the casing through a plurality of spaced and circumferentially disposed air inlet openings Operatively associated with the openings 5| is a circumferentially disposed shutter 52 secured adjustably to the casing l3 by screws 53. I'he shutter is provided with openings equal in number to the openings 5| whereby variable quantities of air may be admitted to the casing l3 through openings 5! when the openings in the shutter 52 are variably positioned with respect to the openings 5 l.

Beyond the fan 48 and secured rigidly to the casing l3 at the periphery thereof is an air straightening baffle 54 having vanes 56 arranged oppositely with respect to the vanes 49 of the fan 43 in such manner as to receive the annular blast of air from the fan 48 between the vanes 56. The pitch of the vanes 56 is such as to neutralize the tendency of the annular blast of air to rotate in response to the operation of the fan 58. Beyond the baflie 54 and upon a central portion thereof inside the vanes 56 are secured a plurality of spaced supporting brackets 58 upon the upper ends of which is secured a stationary oil collecting and burner separating baffle 59. The baffle 59 has flanged portion 6!. disposed in spaced relation to the flange 52 of the casing l3 in such manner as to provide thereoetween an annular discharge orifice 62 for supplying air to the burner combustion chamber from the blast delivered by the fan 48. Beneath the flange Bl the baffle 59 tapers inwardly as is indicated at 63 and 64 to provide with the wall M of the casing I3 an expanding channel 56 through which the blast of air from the fan 48 is delivered to the discharge orifice t2. The slope of each of

theportions

63 and 64 of the bafile 59 is such that any oil not sufficiently vaporized or atomized upon reaching the flange 6| will flow downwardly upon the interior surface of the baffle toward the central portion thereof.

Immediately adjacent the central portion of the baffle 59. is a reversely projecting tapered flange 6'! which with the portion, 34 of the bafile provides a sump or depressed portion 68 in which unvaporized or unatomized oil flowing downwardly within tha baffle. will be collected. Secured upon the upper threaded end of the shaft 22 and projecting through opening 69 formed inside the flange 6'! is a primary spinner ll having a cylindrical passage 12 formed therein, the

lower end of which communicates with the oil supply conduit 4.! in the shaft 22. The upper end of the opening 'EZcOmmunicateS with the widely tapering opening l3 formed in the end surface of the primary spinner 7.l Secured upon the opposite flanged end 74 of the primary spinner 'H is a secondary spinner 1-6, the inner portion '11 of which is tapered downwardly in spaced parallel relation to the portion 6? of the baflie 59.

Beyond the. portion 1! the secondary spinner [6 comprises tapered portions 18. and 19, the slopes of which increase somewhat with respect to the slopes of the'portions 343. and 63, respectively of the baffle 8H in such. manner as to provide. an expanding tapering annular passage 8i between the secondary; spinner T6 and the bafile 59. This passage leadsfromthe sumpor depression 58 in the baffle 59 toward the'fia nge 8!. The depressed portion of; the spinner 16 between the portions ll, and 18 projects downwardly into the depressed portion of the bafile 5 9'between the portions 64: and 61 in such manner that any oil collec ti ngwithin the sump 68 will b e-engaged by the depressed portion of the secondary spinnen l6 and will bethrown outwardly in the direction of the flange 6i through the passage 8|. Some-of the air from the fan 48; will passinwardlybetween the supports 58, through opening 69 at the center of the baffie 59 and outwardly through the passage 8|, there to comingle with oil particles thrown outwardly by the depressed portion of the spinner 16. A further supply of air is added to the mixture so formed within the passage 8| by openings 82 formed through the baiile 59 in a region just outside of the supports 58. This supply of air will be received directly from the straightening bafiie 56 and will be thrown outwardly in the passage 8| by the operation of the secondary spinner 16.

It will be noted that the outer edge of the secondary spinner I6 is somewhat outside of the outer edge of the primary spinner 1|, yet inside the outer edge of the flange 6|. Hence any finely divided particles of oil thrown by centrifugal force outwardly from the outer edge of the primary spinner II will strike the rotating outer edge of the secondary spinner 16, there to be more finely divided by the impact thereof upon the secondary spinner and due to the rotation of the secondary spinner will be thrown by centrifugal force radially outwardly therefrom toward the flange 6|.

Disposed inside the flange 6| is an annular target ring 9| including an outer wall 94 and an inner tapering wall 95. The outer wall 94 is inside the outer edge of the flange 6|, but beyond the outer edge of the secondary spinner 16. Due to such arrangement of walls it is apparent that any finely divided particles of oil which may be discharged from the edge of the secondary spinner 16 will engage the portion of the tapering wall 95 which is immediately adjacent the wall 94. As a result of such engagement, any of the particles which are finely enough atomized to support immediate and efiicient combustion will be deflected outwardly from the wall 95 and will be entrained in the cone shaped blast of primary air from the passage 8| and from within the secondary spinner 1 15. Any oil so atomized will flow either inwardly upon the surface of the wall 95 or outwardly upon the surface of the wall 94.

In order to protect from excessive heat from the burner flame, the region inside the edge of the secondary spinner 16 so as to avoid carbonization of oil upon the surface thereof, there is disposed above the secondary spinner a circularly formed radiant heat baflie 83 which is secured in concentric relation to the secondary spinner it by a rotating stud 84. The stud 84 has a fluted end 85 secured within the cylindrical opening 12 in the primary spinner II for dividing the oil supplied by the supply conduit 41 to the cylindrical chamber into a plurality of parallel streams. Hence, it will be seen that the fluted portions of the stud 84 deliver relatively equal amounts of oil to all portions of the cone shaped end 13 of the primary spinner 1|. The stud 84, being secured rigidly within the cylindrical opening 7 2, will rotate the radiant heat bafile 83 upon the secondary spinner 16.

The baiiie 83, which consists of complementary spaced parts 81 and 88 secured together by rivets 89 terminates adjacent the outer periphery thereof in a region just inside the outer periphery of the secondary spinner 16.

In order to provide means for vaporizing some of the fuel for starting the oil burner there is provided inside the target ring 9| a preignition electrical heating coil 92 which is insulated from the target ring 9| and from other parts of the burner by electrical and heat insulating material 93. When electrical energy is supplied to the coil 92, as when starting the burner, it will be apparent that the unatomized oil previously referred to, which may flow inwardly and outwardly upon the walls and 94 respectively, will be largely vaporized and therefore will render the primary mixture easily ignitable. After starting and during normal operation of the burner it is apparent that the unatomized oil which spreads out upon the surface of the walls 94 and 95 will be largely vaporized by the radiant heat from the burner flame. Any oil not so vaporized upon these surfaces will return by gravity to the sump 58 in the baffle 69.

In order to permit the return to the sump 68 of any particles of oil which may reach the flange 6| and which are not flnely enough divided to be carried away by the flow of primary air through the burner, there is provided in the lower supporting edges of the target ring 9| a plurality of openings 96 through which such oil may flow downwardly upon the surface of the baffle 59.

In order that a suflicient amount of primary air may be supplied to the interior of the secondary spinner 16, there is also provided a series of spaced openings 98, these being formed circumferentially around the spinner adjacent the inner portion thereof.

In operation it will be apparent that any desired quantity of air may be admitted to the casing l3 through the openings 5| by varying the position of the circumferential shutter 52.

This air will be drawn across the outer surface of the motor l8 and will cool the motor due to the contact thereof with the fins Hi. The air then will be discharged by the vanes 49 of the fan 48 in an annular blast upon the straightening vanes 56 which will thereupon deliver the blast of air against the outwardly sloping surface 64 of the baffle 59. Some of this air will move radially inwardly between the supporting bailies 58 and will pass through the opening 69 disposed centrally of the baflie 59.

Of the air which passes through the opening 69 some of this will pass outwardly between the adjacent surfaces of the secondary spinner l6 and the baflie 59 where reatomized oil thrown outwardly by the depressed portion of the secondary spinner 16 will be re-entrained in the air delivered through the passage 8| to the vicinity of the target ring 9|. The remainder of this air will pass through the openings 98 in the secondary spinner 16 where the fuel discharged from the edge of the primary spinner86 will be entrained therein both prior to and during the impingement of such fuel upon the edge of the secondary spinner 16.

Of the air which does not move radially inwardly from the region of the straightening vanes 56, some will pass through the openings 82 Where it will be mixed with the oil and air moving between the adjacent surfaces of the secondary spinner I6 and the bafile 59 from the central region therebetween. The remainder, and by far the greater quantity of air delivered to the region beyond the straightening baffles 56, will move outwardly and forwardly through the expanding passage 66 and the discharge orifice 2. The secondary air so delivered from the orifice I2 will be engaged by the primary air and fuel mixture delivered by the target ring 9|, the general direction of most of which mixture is somewhat radially outwardly. Th engagement beyond the burner of these two moving masses of fluid will result in the development upon the burner of 7 an expanding annular cone shaped mixture of fuel and air which when ignited will burn in a similar formation.

The quantity and direction of the secondary air discharged beyond the discharge orifice I2 is such that when the fuel is properly atomized and vaporized inside the target ring SI, no particles of fuel will pass through the annular cone shaped column delivered by the orifice I2, and consequently it will be unnecessary to provide means inside the combustion chamber for atomizing, vaporizing or burning such fuel.

In order to ignite the combustible mixture so delivered by the burner there is provided at one side thereof an igniter 99 (see also Fig. comprising a bracket Iill secured upon the side of the cylindrical portion II of the combustion chamber or burner supporting wall III. This bracket is provided with two parallel portions I92 and I93 between the upper ends of which is pivotally supported upon rivets I64, an igniter element supporting bar I96. The bar I66 projecting therethrough a pair of elongated terminals I81 and IE5 between the outer ends of which is secured a hot-wire ignition device I99.

The opposite ends of the terminals 191 and I99 beyond the support 596 terminate in contact elements III adapted to engage resilient contact members I12 secured to a lower portion of the bracket I95 upon terminals II3. Disposed between the elongated terminals it? and E98 and secured at one end to arig-id portion of the bracket IQI is a bimetal thermostat I I l, the movable end of which is secured to the pivotally mounted support I99.

The entire structure or" the igniter S3 is located in such position that when the temperature of the thermostatic element It is not affected by the operation of the burner, the thermostat will be contacted in such manner as to position the hot air igniter element I69 in the path of the primary mixture emerging from the edge of the target ring 9 I. In such position the contacts i H and II?! also will be closed so that an electrical current supplied to the igniter will flow through A,

the device and will heat the hot wire element I99 to such an extent that it will ignite the mixture from the burner so delivered. However, after the mixture is so ignited and has burned for sufficient time to heat up all of the various elements of the burner and to produce a hot fire, the temperature of the thermostatic element II4 will be increased to such an extent as toexpand the thermostatic element, thereby moving the end of the element attached to the support I99. The resultant movement of the support I96 will rotate the support I96 upon the rivets I94 to such an extent as to move the hot-wire element I99 outwardly to a position shown in dotted lines in Fig. l and indicated by the numeral II9. In this latter position the igniter will be out of the path of the primary mixture delivered by the burner and the flame resulting therefrom. During this same movement the contacts I I I will move-away from the resiliently supported contacts II2 to such an extent as to break the electrical circuit through the hot-wire element I99.

In Figs. 6. and '7 there is disclosed two slightly different modifications of an electrical control mechanism for operating the burner.

In the modification shown in Fig. 6 the burner is indicated at I5, the preheating ring at 94 and the hot-wire igniter at I09.

The igniter I09 and the heater 94 are wired in series with a thermal safety switch II1 consistill ing of a heating coil 1 IS, a thermostatic electrical conductive element H9 and a reset button I2I. Connected in series with the elements 92, I09 and I18 is another heater element I22 of a thermal timer switch I23, likewise having a thermostatic electrically conductive element I24. The thermostatic elements H1 and I24 are located adjacent the heaters H8 and I22, respectively, so that the thermostatic elements will be affected by the temperature of the heaters. The element H1 is so positioned that it will open the electrical circuit therethrough when the temperature of the heater II9 increases. The thermostatic element I24 is oppositely arranged with respect to the heater I22, that is, it is arranged to open the circuit therethrough when the temperature of the heater I22 increases. The elements 92, I09 and H8 combined have a relatively low resistance compared to the resistance of the heater I22.

The control mechanism disclosed by Fig. 6 also embraces a 3-way switch I26, arelay switch I21 for actuating 3-way switch I26 and a thermostat 12E- for controlling the operation of the relay switch. The 3-way switch 126 consists of a pair of resilient contact bars I29 and I31, the bar I29 being adapted to engage terminal I32 to provide switch number 1-132 when moved in one direction and the bar I3I being adapted to engage terminals I39 and I95. to provide switches numbers 2 and 3 respectively when moved in opposite directions. The contact bar I3I normally is engaged with the terminal I94. The bars I29 and I3! are adapted. to be so moved as to engage the terminals I92, I33 and I34, respectively, by actuating elements I36 and 531, respectively, the two latter elements being rigidly secured upon the end of an armature or core I39 operatively associated with the solenoid I39 of the relay I21. Actuating elements Iufi and I31 are so arranged with respect to the bars I29 and I3I respectively, that the bar 3I will move out of contact with the terminal I34 and into engagement with the terminal I93 prior to the time when the actuating element I39'moves the bar I29 into contact with the terminal I32.

In Fig. 6 the high side of the line is indicated by the numeral I 3 I, the low or ground side by the numeral I42, all of the elements previously decribed being wiredas is indicated in Fig. 6.

circuit disclosed by Fig. 6 is based upon the idea that the thermostat II4 for removing the igniter I99 from the burner flame can finally be used as a protective device to cause the control system to discontinue power to the motor I1 whenever faulty ignition may occur or when there is a flame failure due to the lack of oil or for any other reason.

It will be noted that one side of the thermostat I29 is connected to the high side of the line MI by means of the circuit established through the solenoid coil I39 of the operating relay I21. The other side of the thermostat I28 is connected to the other side of the line I42 by means of the circuit established through switch 3, through the thermostatic element II9 of the thermal safety switch H1 and the elements 92, I09 and I18. Thus the operating relay I21 cannot be energized until the burner cools down sufficiently after a run to cause the contacts III and H2 of the igniter 99 to be closed. It will be noted that the circuit of the thermostat I28 can be completed back to the other side of the line I42 through the heater I22 of the thermal timer switch I23. The heater I22, however, has such a high resistance that it will limit the current flowing through the 9 solenoid I29 of the operating relay I2'I to an insignificant amount. Thus the only way the relay I21 can be closed is when the contacts of the thermostat I 28 are closed and the circuit through switch I21, the igniter 99 and the target ring heater 94 are closed.

When the proper conditions for starting are established, then a closure of the contacts of the thermostat I28 will cause the solenoid I39 of the relay I 21 to be energized. This will cause the core I38 to be moved in such manner as to open switch 3 after switch 2 is closed, and thereafter further movement of the core closes switch I. It will be noted that it is necessary to close the switches in this manner for the reason that switch 2 takes the thermal safety switch II'I, igniter 99 and the target ring heater 92 out of the thermostat circuit and bridges the thermostat in series with the solenoid of the relay I21 across the power line. Immediately after closing switch 2 and the opening of switch 3, the circuit comprising the thermal safety switch I", the igniter 99 and the target ring heater 92 to which the thermostat I28 was connected, is then connected directly to the high side of the line by the closing of the switch I. The reason switch 3 has to be opened before switch I closes is that if the two switches were closed at the same time, there would be a direct short circuit from the high to the low side of the line through all of the switches.

Upon the operation of the relay i2l, current can flow directly from the high side of the line into the igniter 99 and the electrically heated target ring heater 92 through heater I I8 in thermal safety switch 1. Simultaneously the line voltage is put across heater I22 in thermo timer switch I23. The time of closing the switch resulting from the movement of thermostatic element I24 may be preadjusted to a time delay necessary to allow the igniter 99 and the target ring heater 92 to reach proper starting temperatures. When this happens the switch provided by thermostatic element I24 will be closed, causing the motor I I to start the operation of the burner. Under these conditions oil and. air will be properly mixed by the burner and will be ignited by the hot-wire I99 of the igniter 99. When the flame is established the heat of the flame will cause the thermostat M4 to move the hot-Wire element I99 out of the flame and simultaneously open the contacts III and H2. If the flame is established within a predetermined time the current which has been flowing through the heater H8 of the thermal safety switch II'i will not have generated enough heat to cause the thermostatic element II9 of the switch to break the circuit therethrough and the burner will continue to operate under normal starting conditions.

However, under abnormal starting conditions when the flame is not established in a predetermined time after the beginning of the ignition cycle the heat generated in the heater I 53 will be suflicient to cause opening of the switch provided by thermostatic element I I 9, thus shutting down the burner until this switch is closed manually by pressing the reset button I2I. Under conditions of normal operation the thermostatic element I24 of the thermal timer switch I23 will remain closed all the time the thermostat I28 is calling for heat, due to the fact that the heater I22 thereof is bridged across the line by switch I. When the contacts of the thermostat I28 Open, the solenoid I29 of the relay I27 becomes deenergized, thus opening the switches I and 2,

closing switch 3, thus de-energizing the heater I22 of timer switch I23 and thus allowing the heater I22 to cool and to return to its normal starting condition. The heater I22 and the rate of heat absorption of the thermostatic element I24 can be so balanced to compensate for normal changes in line voltage, that is, when the line voltage is down it will require a longer time for the igniter 99 and target ring heater 92 to reach the proper operating temperatures. Under such conditions it will also require a longer time for the thermostatic element I24 to close its switch, thus starting the burner motor I'I. Likewise, in cases of abnormally high voltage it will require less than average time for the igniter 99 and heater 92 to reach proper starting temperatures, in which case, due to the higher voltage across heater I22, the time delay will be reduced, thus starting the motor sooner.

In the structure disclosed by Fig. 7 there is shown a circuit that functions similarly to that shown by Fig. 6. However in this circuit the thermostat I28 is provided with a low Voltage circuit due to the employment of a transformer I43, the primary and secondary coils of which are indicated at I44 and I49, respectively. The relay switch I2! and the 3-way switch I26 also are employed except that the relay I2! is connected to the rest of the control mechanism in a slightly different manner. The thermal safety switch II! is the same type as that employed in Fig. 6, although the thermal timer switch I23 is a snap action type of switch mechanically coupled to the core I38 of relay I2I by a linkage indicated by dotted lines at I4! and pivoted at I48. When the solenoid I31 of the relay I2'I is deenergized, its core drops to the unenergized position thereby transmitting motion through the linkage I 47. This motion causes the thermostatically actuated element I24 of the switch I23 to be moved off of a magnet indicated at I49 and to return to the starting position. Also in Fig. '7 a light responsive contact switch I5I is employed instead of the thermostatically actuated element I I4 employed in Fig. 6, and the target ring heater 92 is not employed in series with the igniter 99. Also the igniter employs a high tension spark device indicated at I52 instead of the hot wire element I99. This spark device is provided with high voltage current by a transformer I53, the secondary coil l54 of which is in circuit with the spark device I52, while the primary coil I56 thereof is connected through the control mechanism across the line.

For normal starting the furnace will be relatively cool and the light responsive switch I5I will be closed. When the contacts of the thermostat I28 close, as they will do when heat is required, a current will flow through the thermostat out to switch I5I in the burner, back through switch I to one side of the solenoid I39 of relay I21, through the solenoid I39, through the thermostatic element I I 9 of switch I I I, back to the other side of the secondary winding I46 of the transformer I43. Current will simultaneously start flowing through the heater IIB which supplies sufiicient heat to operate the thermostatic element H9 in a predetermined length of'time. When the core I38 of the relay I2! is energized the switches I and 2 are closed and switch I is opened. Upon the closing of switch 2 the solenoid of relay I2! is no longer in series with the light responsive or fire-sensing switch I5I but is connected directly with the thermostat I28, so that switch I5I can open without causing the 11 core I38 in relay I21 to move outwardly of the solenoid I39.

The closing of switch I connects the common line and secondary terminal to the motor and to the ignition device I52. The return from the motor is to the high side of the line while the return from the ignition device is to the secondary winding I54 of the transformer I53. The closing of the ignition circuit causes the heater I22 to open the temperature operated switch element I25 within a predetermined time. When the element I24 does open the circuit therethrough, it is-maintained in the open position by the magnet MS. Upon opening of this switch the heating element I IE will start :to cool down, thus preparing itself for the next time the burner starts.

Under abnormal starting conditions when a flame is not established within the predetermined time allowed for this purpose, the fire-sensing switch II will not have opened and suflicient heat will not have been generated in the heater I I8 to cause the element "I I9 to break the circuit therethrough and through the common circuit of the transformer secondary and the power line.

Where it is not desirable to use a common circuit for two voltages it is necessary to use a double pole switch in place of the switch II! and another double pole switch instead of the single contact between terminal I32 and bar I29. Under such conditions it will be necessary to manually close the thermal safety switch I I! by pushing the reset button I2I which will reestablish normal circuit conditions. Under normal operating conditions when the circuit is open through thermostat I28 the core I38 becomes deenergized, thus closing the switch between terminal 34 and bar I3I and opening the other two switches of the switch structure I26. Thus the circuit is established for starting and when the fire-sensing switch to close, the burner can be restarted upon the closing of the circuit through thermostat I38.

While we have illustrated and described preferred embodiments of our invention, it is understood that these are capable of modification, and we therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall within the purview of the following claims.

We claim:

1. An oil burner comprising a casing having a flange at one end providing an opening therein, a stationary baflie having a flange disposed in spaced relation to said casing flange, said flanges providing an annular opening therebetween for the discharge from said burner of an annular blast of secondary air, said bafiie also being formed to provide an oil sump therein and an opening for the admission to the interior of said baflie of primary air for said burner, a fan for supplying to said openings said primary and said secondary air, an oil spinner located within said baifie flange, an oil metering pump for supplying burner fuel to said spinner, means for driving said spinner, said fan and said pump, and a target ring disposed within said baflie flange in position to be engaged by the oil from said spinner and in the path of the primary air from said baflle opening for forming within said annular blast of secondary air an outwardly moving mixture of atomized fuel and air, said spinner comprising a dished member arranged for rotation on a vertical axis and within and concentric relative to said target ring, said target ring being arranged to drain by gravity unatomized oil from I5I cools down sufficiently said targetring into saidsump, said spinner being arranged to project -into said sump for reatomizing the oil collected therein, said opening in said bafiie being disposed radially inwardly of said sump whereby the air admitted by said opening will be thrown outwardly by said spinner for entraining therein the reatomized oil from said sump.

2. An oil burner comprising a casing having a flange at one end providing an opening therein, a stationary baflie having a flange disposed in spaced relation to said casing flange, said flanges providing an annular opening therebetween for the discharge from said burner of an annular blast of secondary air, said bafile also being formed to provide an oil sump therein and a plurality of openings for the admission to the interior of said baflle of primary air for said burner, a fan for supplying to said openings said primary :and said secondary air, an oil spinner located on the downstream side of said bafile but within said baflie flange, an oil metering pump for supplying burner fuel to said spinner, means for driving said spinner, said fan and said pump, and a target ring disposed within said bafile flange in position to be engaged by the oil from said spinner and in the path of the primary air from said bafile openings for forming within said annular blast of secondary air an outwardly moving mixture of atomized fuel and air, said spinner comprising a dished member arranged for rotation on a vertical axis and within and concentric relative to said target ring, said target ring being arranged to drain by gravity unatomized oil from said target ring into said sump, said spinner being arranged to project into said sump for reatomizing the oil collected therein, said plurality of openings in said baflie being disposed radially both inwardly and outwardly of said sump whereby the air admitted by said opening will be thrown outwardly by said spinner for entraining therein the reatomized oil from said sump.

3. An oil burner comprising a casing having a flange at one end providing an opening therein, a stationary baffie having a flange disposed in spaced relation to said casing flange, said flanges providing an annular opening therebetween for the discharge from said burner of an annular blast of secondary air, said baffle also being formed to provide an opening for the admission thereto of primary air for said burner, a fan for supplying to said openings said primary and said secondary air, an oil spinner located within said bafiie flange, means including an oil metering pump for supplying burner fuel to the upper side of said spinner, means for driving said spinner, said fan and said pump, and a target ring disposed within said baffie flange in position to be engaged by the oil from said spinner and in the path of the primary air from said bafiie opening for forming within said annular blast of secondary air an outwardly moving mixture of atomized fuel and air, means for supplying unvaporized oil from said target ring to the underside of said spinner in order to permit the projection of such unvaporized oil thereby upon rotation thereof into engagement with said target ring, said spinner comprising a dished member arranged for rotation on a vertical axis and within and concentric relative to said target ring, said spinner also being provided with an opening for the admission therein of a portion of the primary air admitted by said baflie opening, whereby said primary air will be thrown radially outwardly by centrifugal force on both sides of said spinner for mixture with the oil discharged by said spinner so as to form a primary mixture of atomized fuel and air for mixture with said annular blast of secondary air.

4. An oil burner comprising a casing having a flange at one end providing an opening therein, a stationary baffle having a flange disposed in spaced relation to said casing flange, said flanges providing an annular opening therebetween for the discharge from said burner of an annular blast of secondary air, said baflle also being formed to provide an opening for the admission thereto of primary air for said burner, a fan for supplying to said openings said primary and 1 said secondary air, an oil spinner located within said baflie flange, means including an oil metering pump for sup-plying burner fuel to the upper side of said spinner, means for driving said spinner, said fan and said pump, and a target ring disposed within said baiiie flange in position to be engaged by the oil from said spinner and in the path of the primary air from said bafile opening for forming within said annular blast of secondary air an outwardly moving mixture of atomized fuel and air, means for supplying unvaporized oil from said target ring to the underside of said spinner in order to permit the projection of such unvaporized oil thereby upon rotation thereof into engagement with said target ring, said spinner comprising a dished member arranged for rotation on a vertical axis and within and concentric relative to said target ring, said spinner also being provided with an opening for the admission therein of a portion of the primary air admitted by said bafile opening, whereby said primary air will be thrown radially outwardly by centrifugal force both within and without said spinner, and a radiant heat bafiie disposed outwardly of said spinner for protecting the interior of said spinner from the radiant heat resulting from the operation of said burner.

5. An oil burner comprising a cylindrical casing and an electric motor, said casing being provided with a shaft disposed longitudinally thereof and driven by said motor, said shaft having an axially disposed oil supply conduit formed therein, a fuel metering pump mounted in said casing for operation by said shaft, said fuel metering pump being adapted to discharge metered quantities of oil through said conduit in said shaft for operating said oil burner, a fan mounted on said shaft adapted to induce a flow of air throughout said casing for operating said burner, said casing beyond said fan being provided with a stationary bafiie having the outer portion thereof formed to provide an annular target ring, said target ring being spaced concentrically with respect to said casing to provide Cir n at

an annular secondary air passage between said target ring and the adjacent end of said casing, a primary spinner disposed on the end of said shaft on the downstream side of said baffle and communicating with the conduit formed in said shaft for distributing the oil supplied by said conduit radially outwardly from said spinner, and a secondary spinner mounted on the end of said shaft for rotation therewith and with said primary spinner, said spinner comprising a dished member arranged for rotation on a vertical axis and within and concentric relative to said target ring, the periphery of said secondary spinner being disposed for receiving the oil discharged radially by said primary spinner, for atomizing a substantial portion of said oil and for discharging the unatomized portion of said oil from the outer edge thereof against said target ring, said stationary baille being provided with a centrally disposed opening around said shaft for the admission of primary air to the space between said baffle and said secondary spinner, said baffle and secondary spinner also being provided with concentric depressed portions with the depressed portion of said spinner extending within the depressed portion of said baiiie, said depressed portions in said baffles being adapted to collect unvaporized fuel from said target ring, said fuel when collected in sufficient quantity to be engaged by the depressed portion of said secondary spinner being thrown radially outwardly by said depressed portion of said secondary spinner and comingled and entrained within said primary air between said target ring and said secondary spinner, said mixture so formed being discharged axially outwardly of said burner from said target ring.

KEMPER M. I-IAMMELL.

ROBERT R. WITHERELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 844,605 Meyer Feb. 19, 1907 1,497,829 Allen et al June 17, 1924 1,562,799 Smith Nov. 24, 1925 1,575,170 Knopp Mar. 2, 1926 1,689,667 Free Oct. 30, 1928 1,695,030 Scheminger Dec. 11, 1928 1,782,937 Perry Nov. 25, 1930 1,901,271 Taft Mar. 14, 1933 1,926,394 McCabe Sept. 12, 1933 1,996,336 Junkers Apr. 2, 1935 2,027,632 Chadwick et a1 Jan. 14, 1936 2,033,600 Washburn Mar. 10, 1936 2,416,932 Litzenberg Mar. 4, 1947