US2241327A - Thermostatically controlled oil burner installation - Google Patents

Description

L. O. SELBY May 6, 1941.

THERMOSTATICALLY CONTROLLED OIL BURNER INSTALLATION Filed Oct. 17, 1936 2 Sheets-Sheet 1 L. O. SELBY May ys, 1941.

A'IHEMOSTYATIGALLY CONTROLLED OIL BURNER INSTALLATION 2 Sheets-Sheet? Filed Oct. 17, 1936 Patented May 6,' `1941 THERMDSTTICALLY CONT'BOLLED OIL BURNER INSTALLATION Lynn tis Selby, Hartford, Conn.; asslgnor to The ISparmal Engineering Corporation, a corporation of Connecticut Application October 17, 1936, Serial No. 106,203

(ol. 15s-ss) 15 claims.

My invention relates to thermostatically controlled oil burner installations.

In oilburner installations requiring consider able heating capacity and utilizing large Iburners, the difdculty arises that if the temperature controlled valve is adjusted to maintain a minimum flame when the valve is shut off, there is too little heat available to maintain a large burner base heated to a temperature sumciently high to volatilize the incoming oil when the valve opens. This results in smoking and carbonization of the burner, ultimately rendering the burner inoperative. On the other hand, if the pilot flame is increased in intensity to a point where it is capable of adequately preheating a large burner base. there is not only serious waste of fuel when the valve is shut off, but frequently, as in water heating installations, the additional heat is not wanted and may result in overheating of the water, during the night when water is not being used, for example, which is dangerous.

My invention has among its objects to provide an improved thermostatieally controlled oil burner installation, and especially one in which the burner has a wide variation in heating capacity between its low llame and high flame operating conditions. vide an improved burner of the distillate type having high heating capacity and an improved A further object is to protemperature controlled valve for insuring preheating of the burner grooves prior to the admission offuel thereto and capable of automatically varying the supply of fuel from the minimum required to maintain a pilot flame in the burner, to the maximum required to obtain full heat Without smoking and carbonization of the burner. A further object is to provide an improved temperature controlled valve capable of supply,- ing fuel to a burner having several stages, or burner grooves, each of which has a separate oil supply means under the control of an improved temperature responsive valve and one stage of which constitutes a pilot burner for maintaining a minimum flame and for preheating the next stage prior to the admission of fuel to the same. A still further object is to provide such an improved multi-'stage burner and improved automatic temperature controlled valve means controlling the same and requiring only a single' metering valve. These and other objects and advantages of my improved construction will, however, hereinafter more fully appear.

In the accompanying drawings, I have shown for purposes of illustration two embodiments which my invention may assume in practice.

In these drawings- Figure 1 is an elevation partly in section. of an oil burning refrigerator equipped with my improvements, only those partsof the refrigerator being shown which are necessary for an understanding of the invention:

Fig. 2 is a full size sectional view of the thermostatically controlled valve of Figure 1;

Fig. 3 is a full size view whith certain of the parts of Figure 1 broken away, showing the valve iilunger in elevation and the valve casing in secon; Y

Fig. 4 is a detail view, partly in section. of a construction for connecting the valve plunger directly to the expansible fluid operated member of the thermostat;

Fig. 5 is an elevation, partly in section, of a. modified valve construction embodying certain improvements and shown as applied to water heating;

Fig. 6 is a plan view of the float chamber and valve assembly of Figure 1 with the cover removed;

Fig. 7 is a section on line l-l of Figure 6;

Fig. 8 is a section `on line 8-8 of Figure 6. and

Fig. 9 is a sectional elevation of a modified construction of oil supply means.

In Figures 1 to 3, I have shown one form of my improved thermostatically controlled valve A adapted to control a distillate type oil burner B of a well-known Servel refrigerator, indicated generally at C and including the usual boiler l, freezing unit. 2, fuel supply tank 3 and constant level iloat chamber l, provided with a cover 4a, all in such manner as hereinafter described to enable improved results to be obt II to receive the lower reduced screw threaded end I2 of the valve A.

In accordance with the present invention, the burner B is a large burner of high heating capacity including an outer annular ring, or burner groove, I3 having a carbon leg 13a and an inner annular ring, or burner groove, I4 having a carbon leg I4a. The rings I3 and I4 are integrally connected together by three radial arms I5, one of which is provided with an oblique passage I6 (Figure 1) extending from the inner groove downwardly into the outer groove for a purpose hereinafter explained. The oil is supplied to the carbon legs I3a and I4a through pipelines I1 and I8, respectively, including usual metering valves (not shown), -both oil supplies being under the control of the same thermostatically operated valve A.

As shown most clearly in Figures 2 and 3, the valve A comprises an elongated hexagonal casing I9 which enables the lower screw threaded portion I2 thereof, previously mentioned, to be turned by a wrench into the passage II in the iioat chamber, a suitable gasket 28 being provided to obtain an oil tight seat. The valve casing I9 has an enlarged axial Abore 2|, constituting a plunger passage, screw threaded at its upper end at 22, which communicates with the duct I through a smaller passage 23 in the lower end portion I2. The casing I9 is also formed with diametrically opposite externally threaded bosses 24 and 25 for attachment of pipe lines I8 and I1. These bosseshave lateral oil supply passages 26 and 21, respectively, which extend into the plunger passage 2l. As shown most clearly in Figures 2 and 3, the passage 26 is of the same diameter as passage 21 but is located slightly above the latter.

'Ihe plunger 28 for controlling the admission of oil to supply passages 26 and 21 is formed with three different diameters and comprises a lower portion 29 which has a close running t in the plunger passage 2|, an intermediate portion 38 of reduced diameter and an upper portion 3I of still further reduced diameter forming an upwardly facing shoulder 32. The upper portion 3I is guided in an externally threaded bushing 33 which is vertically adjustable in the upper screw threaded end of the casing I9 by means of the hexagonal ange 34 to determine the upper limit of plunger travel, engaging at its lower end the shoulder 32 on the plunger. The lower plunger portion 29 has an annular groove 35 forming a lower control portion 36 having an upwardly facing shoulder 36a. As shown most clearly in Figure 3, the control portion 36 is disposed in the vicinity of the outlet or supply passages 26 and 21 and controls the admission.

of fuel thereto from the groove 35. The groove 35 communicates through lateral ports 31, two being shown herein, with an axial bore 38 which extends throughout the plunger. The bore 38 has a reduced lower end portion 39 which communicates with the bottom of the plunger passage 2I and which provides a seat 39a, for a needle valve 40 which has its upper enlarged end 4I screw threaded intol the upper screw threaded portion 42 of passage 38, a hexagonal flange 43 being provided at the upper end for rotating the needle valve relative to the plunger. To assist in the adjustment of the needle valve, diametrically opposed flat faces 44 are provided for holding the plunger against rotation. A look nut 45 is also provided on the needle valve for holding the same in adjusted position.

It will be evident from the above description that an oil passage is provided through the valve A from oat chamber 4 through the inlet passage 23, plunger passage 2I, axial passage 39 in the plunger,.ports 31 to groove 35 and thence through outlet passages 26 and 21 and pipe lines 75 I8 and I1 to the burner grooves I4, I3; and it will also be evident that as the plunger is reciprocated in the plunger passage, lthe flow of oil through the outlet passages 26 and 21 will be varied as theannular groove 35 is brought into and out of registry with said outlet passages 26, 21. More particularly, it will be noted that in the position shown in Figure 2, the control portion 36 completely cuts off passage 21 and permits only a minimum orice in the passage 26. as determined by the adjustment of sleeve 33. As the plunger is moved downwardly, the passage 26 is rst partially uncovered while passage 21 still remains covered so thatA oil is supplied progressively to passages 26 and 21.

'I'he reciprocation of the plunger 28 is gov..

erned by temperature responsive means including a horizontally disposed, vertically expansible wafer 46, the upper end wall 46a.' of which carries a exible supporting diaphragm 41 which has its periphery clamped between upper and lower annular rings 48 and 49 comprising a supporting frame. 'I'his frame is adapted to be moved laterally from its normal position over the valve A about a vertical standard 58 supported on the constant level chamber 4 to permit removal of the valve. The upper ring 48 also has a transverse strip 5I spaced above the wafer in which is journaled a manually rotatable study 52 which acts to depress the diaphragm 41 when rotated. Therotation of the stud 52 is governed by a manually controlled button 53 and a flexible control cable 54, in a well known manner. The wafer 46 is of a usual typel adapted to contain an expansible fluid, .and communicates through a small tube 55 with a temperature responsive element 56 located in the refrigerator compartment adjacent the cooling unit 2. It will be understood that the tube 55 and temperature responsive element 56 likewise contain expansible uid and that changes in iiuid presthe iiuid in element 56 are conveyed to and in! lluence the wafer 46.

The plunger 28 is constantly biased upward by a spring 51 located in the plunger passage 2l beneath the plunger. A vertically adjustable anvil 58 is provided in the upper end of the plunger assembly, being screw threaded into the upper end portion 4I of the needle valve. The spring 51 constantly biases the anvil 58 into engagement with the lower end Wall of wafer 46, the plunger 28 being checked .in its upward movement under the action of spring 51 by the engagement of shoulder 32 with the lower end of the low ame adjusting sleeve 33, as previously described. A definite relation exists between the shoulder 32 on the plunger and the location of the groove 35 relative to outlet passages 26 and 21, these parts being so arranged that the engagement of the lower end of sleeve 33 with the shoulder 32 determines the adjustment of the low llame orifice above the shoulder 36a in the outlet passage 26 which communicates with the inner ring I4 of the burner.

In the operation of this form of my invention, it will be evident that the oil is maintained in the constant level chamber 4 at the level 4b which is high enough to admit oil to the burner base, but is below the top of the burner base so that ooding of the burner is impossible, even if the burner should go out. Also, it will be clear that as determined by the position of the plunger 28 in the plunger passage 2| oil will be supplied from the float chamber 4 through the duct l0, axial passages 23 and 39 in the valve casing and plunger respectively, past the needle valve 40, through lateral ports 31 to the annular groove 35 and thence to the outlet passages 26 and 2l,4

as permitted by the location of the control portion 36, the maximum flow of oil at any time to the burner being controlled by the setting of the needle valve 40 which constitutes the high llame adjustment.

With the plunger in the position shown in Figures 2 and 3, the shoulder 32 on the plunger is in engagement with the lower end of the low flame adjusting sleeve 33 which indicates that the refrigerator compartment is at its proper temperature and the burner is being supplied with only suflicient fuel from the groove 33 through passage 26 to maintain a pilot flame in the inner burner ring I3. As the temperature in the refrigerator C rises, the expansible fluid in the element 56 will expand causing the Wafer 36 to expand and depress the plunger 23 against the action of spring 3i. As the plunger is depressed, the minimum orifice between the control shoulder 36a and the top of outlet passage 23 is gradually increased, during which time the inner ring is preheating the outer ring. Not until the inner ring is burning at a substantial rate is outlet passage 2l uncovered by the control edge 33a to admit fuel to the carbon leg i3d of the outer ring. Further note that the initial opening thus provided in the 'passage 2l is very small, in the nature of the pilot opening previously described, and that not until the passage 26 is fully uncovered and the inner ring burning at substantially a maximum ame, is any material amount of oil supplied to the outer ring. Thus as the oil supplied through pipe line il reaches the carbon leg i3d, this carbon leg has already been highly preheated by the inner ring which is now burning with a high flame. As the oil vapor rises from the carbon leg into the outer ring, some of the vapor is drawn into the upwardly inclined passage i6 by the draft set up by the iiarne in the inner ring. As this highly volatile gas reaches the flame above the inner ring, it becomes ignited and fires back into the outer ring, thus igniting the oil vapor rising therein. As the plunger continues to move downwardly, an increasing amount of oil is supplied to the outer ring until the burner is operating at its full heating capacity, as determined by the setting of the needle valve 43. When the refrigerator compartment has been brought to the proper temperature, as evidenced by the contraction of the wafer, the supply of oil to the outer ring will be diminished and finally cut ol, following which the supply of oil to the inner ring will likewise he diminished to a pilot flame.

The adjustment of the valve is very simple. First, the plunger is depressed to its full open position in which the groove 35 is in communication with both supply passages 26 and 2l. The metering valve 43 is then adjusted to admit the maximum amount of oil which the burner can consume Without smoking. The plunger is then released and the low llame adjustment is made by rotating the sleeve 33 adjacent the shoulder 32 to depress the plunger 28 until the annular edge 36a is slightly below the point of cut on of passage 26, permitting only a minimum flow of oil to the inner ring i4 to maintain the pilot flame. The anvil 58 is then adjusted relative to the plunger 28 to obtain the proper temperature setting for the thermostat. It will be noted that the low flame adjustment can be varied in this construction without affecting the adjustment of the anvil 63 relative to the wafer 66.

In Figure i I have shown a modiiied construction which may be used to connect the upper end of the plunger 28 directly to the lower wall of the wafer 46, thus eliminating the necessity for the spring 6l against which the plunger has to act in the above described construction. As shown inthis figure, the lower end wall of wafer 46 is provided with an external screw threaded boss 59 having a socket 59a to receive the ball 60 on the upper end of a member 6i which corresponds to the anvil 58 of the previous construction.- A cup shaped member 62 is screw threaded on to the boss 63 to hold the ball @El in the socket 59a while permitting relative movement between the ball and its socket. This construction provides a more sensitive tempera ture regulation since the plunger does not have to act against a spring, instead being moved positively in both directions by the wafer, and the necessity for troublesome matching of the springs with the amount and character or erfpansible iluid in the wafer during manufacture is eliminated. l

In Figures 5 to 8 I have shown a modiiied construction inwhich my invention is applied to water heating. In this modified construction an improved valve D is adapted to control a double ring distillate burner B in a stack heater E for heating a Water storage tank F, including the usual heating coil 63 having connections 33a and 63h to the top and bottom oi' the storage tank respectively,

Oil from a tank, not shown, is supplied through a feed line E6 to a constant level oat chamber 65 adjustably supported on a vertical standard 66. Oil is maintained at a constant level in the float chamber 66 by means of a float valve and float similar to that described in Figures l to 3 above. In this construction, however, a metering valve 6l is screw threaded into a partition dd between the iioat chamber and the duct lil and constitutes the maximum ame adjustment for the burner. This metering valve is .of a well known construction including a stern 33 which cooperates with a seat lli to control the amount of flow which can pass through the valve into the duct it.

In this form, the thermostatically controlled valve comprises a generally cylindrical body li having a small axial plunger passage 12 of uniform diameter which extends through the lower externally screw threaded portion i3 into the duct l0. The plunger passage l2 is also screw threaded at its upper end to receive a bushing id which constitutes a low flame adjusting member, as hereinafter described. The plunger 'passage 'l2 is in direct communication with the supply lines il' and i3 leading to the outernd inner burner grooves i3 and id, respectively, through the horizontal outlet supply passages 'l5 and lli in the valve casing li. 'I'hese diametrically opposed supply passages in this preferred valve construction are located on a common center. but the passage 76, through which fuel is supplied to the inner burner ring, is larger in diameter than passage l5 from which fuel is supplied socket'connection at 18 with a connecting rod 19 of smaller diameter which extends through the bushing 14 and is screw threaded at its upper end into a depending boss 80 carried by the lower end wall of an expansible bellows 8l. The upper end wall 82 of the'bellows 8l has an upstanding screw threaded stud 83 which is fixed to the horizontal portion 84 of a C-shaped bracket 85 carried by the upper end of the valve casing 1I, a nut 86 being provided to clamp the bellows in place. The boss 83 has an axial passage therethrough communicating with the interior of the bellows and through a small capillary tube 81 with a contact button 88 secured by a band 89 to the storage tank. The contact button 88 is secured to the storage tank F preferably near the bottom thereof and is responsive to the temperature of the water in the tank. The bellows 8| is of a well known type and is adapted to be expanded and contracted by an expansible uid contained therein and in the contact button 88. It will be understood that variation in iiuid pressure due to expansion and contraction of the iiuid in contact button 88 is conveyed to and expands and contracts the bellows to reciprocate the plunger 11 in the plunger passage 12.

The operation of this improved form of my valve will be evident from the detailed description in connection with the previous forms, the principal dilierence being that in the hot water system of Figures 5 to 8, the plunger 11 cuts oil? the oil supply upon expansion of the bellows and increases the supply of oil upon contraction thereof. Thus in the position of the plunger in Figure 8, a suflicient opening in passage 16 is provided to maintain a pilot iiame in the inner ring of the burner. In this position of the plunger, the low flame adjusting sleeve 14 is engaged by the adjustable stop nuts 98, as shown most clearly in Figure 8. Upon lowering of the temperature of the water in storage tank F, and the consequent contraction of the bellows 8|, the plunger 11 will be raised to first increase the fuel supplied to the inner ring of the burner through the supply passage 16. Due to the smaller diameter of passage 15, the lower end of the plunger will not permit oil to flow to the outer ring until an increased amount of oil has been supplied to the inner ring and the latter has been brought up to a high heat. This enables the inner ring to preheat the outer ring as previously described before oil is admitted to the outer ring.

In Figure 9 I have shown a somewhat modied construction of iioat chamber which has certain advantages over that shown in Figure 8. In this construction, the i'loat chamber 65 has a laterally extending base portion 9| provided with upper and lower lateral passages 92 and 93 of relatively small `cross section, the passage 92 terminating within thebase portion while the lower passage 93 communicates with the oat chamber. Both passages are closed at their outer ends by pipe plugs 94. 'I'he thermostatically controlled valve D has its lower screw threaded portion 13 threaded into said base adjacent the extremity thereof and has its plunger passage 12 communicating with the upper passage 92. The metering valve 61 has its lower screw threaded portion 95 similarly threaded into said base portion adjacent the float chamber and has a needle valve 69 cooperating with a seat 95 formed in a vertical passage 91 between passages 92 and 93. It will be evident that oil from float chamber 65 will pass through passages 93, 91 and 92 to the plunger passage 12. The advantages of this construction arise from Athe new control of the ii'uid between themetering and thermostatic valves,.as well as the small cross section of they various passages Ibetween the metering valve and the plunger passage of the thermostatic valve. This construction results in better and more uniform regulation of the oil supplied to the burner, especially upon opening of the thermostatic valve.. This is due to the fact that there is only asmall volume of oil contained in the passages between the needle valve and the plunger and that this body of oil is below the outlet ports in the thermostatic valve, as distinguished from the construction shown in Figure 8 in which a considerable volume of oil may accumulate between the metering valve and the thermostatic valve to a height equal to the oil level in the float chamber in such manner as to cause an excess of oil to be supplied to the burner through the thermostatic valve upon opening movement of the latter.

It will ybe evident that as a result of my invention I am enabled to control the admission of fuel to burners of very high heating capacity by means of a thermostatically controlled valve while at the same time maintaining only a minimum pilot flame in the burner-when the valve is closed. Further, it will be noted that I am able to maintain a small pilot ame in such a large burner and am able automatically to control the admission of fuel to the burner to bring the same to full heating capacity without causing the burner to smoke and carbonize by the admission of oil to cold burner surfaces. It will also be noted that as a result of my improvements, the control is uniform and effective, as well as economical, Whiler also permitting continuous automatic operation with aminimum of attention and quite complete freedom from smoking and carbonization. I am also enabled to control such an improved installation with a single metering valve, all as above described. These and other advantages of my improved construction will. however, be apparent to those skilled in the art.

This application is a continuation in part of my application Serial No. 75,991, filed April 23, 1936.

While I have in this application specifically described several embodiments of my invention, it will be understood that these forms of the same are shown for illustrative purposes and that the invention may be modified and embodied in other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In combination, an oil burner having adjacent high and low heat burner grooves, oil supply means, and means for supplying oil separately to said burner grooves including an expansible fluid actuated expansible member and valve means controlling said separate supplies of oil to said grooves and having both supplies controlled by said member to vary gradually the amount of oil supplied to the burner in accordance with temperature changes affecting said expansible uid from the minimum amount of oil required to maintain combustion in the low heat groove to the maximum amount of oil which can be consumed in both grooves.

2. In combination, an oil burner having low and high heat grooves, an il reservoir, means for supplying oil from said reservoir separately to said grooves including a valve having a movable member and separate oil supply means leading from said valve -to said respective burner grooves and controlled by said member, and expansible iiuid operated means for opening said valve member to rst gradually increase the amount of oil supplied to said low heat groove from the minimum amount required to maintain combustion therein to an amount closely approaching the maximum amount which may be consumed in said low heat groove and thereafter to admit oil to said high heat groove and in gradually increasing -amounts until the burner is supplied with the maximum amount of oil which it can consume without smoking.

3. In combination, an oil burner having adjacent high and low heat burner grooves, an oil reservoir, means for supplying oil from said reservoir to said grooves including a valve having an oil inlet passage and oil outlet passages separately communicating with said grooves, said valve also having a movable valve member movable relative to said outlet passages to supply oil progressively to said grooves, said valve member increasing to an amount closely approaching a maximum, the amount of oil supplied to said low heat groove and subsequentlyV admitting oil to said high heat groove and increasing the amount of oil admitted thereto until the maximum amount of oil which can be consumed in both grooves is being supplied by said valve, and means arresting the movement of said member in the reverse direction for maintaining a minimum orice in the outlet passage last to be controlled for maintaininga pilot flame in said low heat groove and preheating the adjacent high heat groove.

4. In combination, an oil burner having a low heat groove and a high heat groove, an oil reservoir, means for supplying oil from said reservoir progressively to said grooves including a valve having an oil inlet passage and oil outlet passages separately communicating with said grooves, said valve also having a movable valve member movable across said outlet passagesto admit oil iirst to said loW heat groove to preheat said high heat groove and subsequently to admit fuel to said high heat groove, means arresting thev movement of said valve member in a reverse direction for maintaining a minimum orice in the outlet passage communicating with said low heat groove, and an expansible fluid operated expansible member for actuatingv said valve member across both said outlet passages so graduallyl upon. temperature increases that the volume of oil supplied to said low heat groove and subsequently to said high heat groove does not at any time exceed the amount which can be vaporized by the heat of the burner.

5. In combination, a double groove burner having a fuel supply, and means normally main.- taining a minimum fuel ow to one of said burner grooves at minimum temperature and responsive to temperature increases to uniformly increase the fuel flow to the burner directly as the temperature rises comprising an expansible iiuid operated valve having an inlet passage communicating with said fuel supply and outlet passages separately communicating with said burner grooves and a movable valve member progressively controlling the admission of fuel to said burner grooves.

6. In combination, an oil burner having adjacent high and low heat burner gro'oves, an oil reservoir common to both of said grooves, and means for supplying oil progressively to said grooves from a minimum amount required to maintain a low ame in said low heat groove to the maximum amount of oil both grooves can consume Without smoking including a thermostatically controlled valve having an oil inlet passage connected with said reservoir and vertically spaced oil outlet passages 'separately connected with said burner grooves, said valve also having a vertical plunger passage intersecting said outlet passages, a plunger movable therein to vary the cross section of said outlet passages, means for limiting the movement of said plunger in one direction whereby to maintain a minimum iiow of iiuid to one of said burner grooves, and temperature responsive means for actuating said plunger in the reverse direction to rst uncover said minimum flow passage and to subsequently uncover said other outlet passage.

7. In an oil burner control valve, a valve casing having an inlet passage and two outlet passages, a. movable valve member controlling said outlet passages and having a control portion movable progressively across said outlet passages to vary the cross-section of the same, expansible iiuid operated means for moving said valve member, and adjustable means arresting said member in one direction of movement for maintaining a minimum orifice in said outlet passage last to be controlled.

8. In an oil burner control valve, a casing havingan axial passage, oil inlet means adjacent one end of said passage, two laterallyextending oil outlet passages communicating with said axial passage above said inlet means, one of said outlet passages having its axis located nearer said inlet means and @both having portions located in the same horizontal planes, and a plunger reciprocable in said axial passage having a control portion progressively movable in opposite directions across said outlet passages to cover and uncover both of the same.

9. In an oil burner control valve, a casing having an axial passage, oil inlet means at one end of said passage, oil outlet passages communicating with said axial passage above said inlet means, and a plunger reciprocable in said axial passage having a control portion progressively movable across said outlet passages to cover and uncover both of the same, and means adjustably screw threaded into the opposite end of said axial passage from said inlet means for arresting said'plunger in one direction of movement thereof.

l0. In an oil burner control valve, a casing having an axial passage, oil inlet means at one end of said passage, oil outletpassages communicating with said axial passage above said inlet means, and a Aplunger reciprocable in said axial passage having a control portion progressively movable across said outlet passages to cover and uncover both of the same, expansible and contractible uid operated means actuating said plunger in response to temperature changes, and cooperating stop means on said casing and plunger between said fluid operated means and said outlet passages arresting said plunger upon contraction oi' said uid operated means for preventing complete cut-off of the last outlet passage to be controlled.

11. In .a fuel control valve for oil burners, a

valve casing having a vertical plunger passage' and two radially directed outlet passages of diiferent cross sectional areas communicating with said plunger passage, and a temperature responsive plunger reciprocable in said plunger passage having a control portion movable across said 'outlet passages in one direction of movement to increase the cross section thereof in a progressive manner and movable in a reverse direction to reduce the cross section thereof, cutting oif one passage completely, and cooperating stop means limiting the movement of said plunger in the latter direction of movement to maintain a minimum orifice in the last passage to be moved across.

12. In a fuel control valve for oil burners, a valve casing having a control passage and a plurality of outlet passages communicating with said control passage, and a control member movable in said control passage to vary progressively the cross section of said outlet passages, said casing also having an inlet passage communicating with said control passage and open in all positions of said control member and said control member having a passage communicating axially with said inlet passage and also communicating laterally through said member with di'erent outlet passages in diierent positions of said member, and expansible uid operated means for moving said control member progressively acrosssaid outlet passages in response to temperature changes to vary the cross-section of said outlet passages gradually.

13. In a fuel control valve for oil burners, a valve casing having an annular control passage and a plurality of outlet passages communicating with said ,control passage, and a temperature responsive annular control member movable in said control passage to vary progressively the cross section of said outlet passages, said casing also having an inlet passage communicating with said control passage and open in all positions of said control member and said control member having a passage communicating with said inlet passage and also with different outlet passages in different positions of said member, including an annular groove intermediate the ends of said control member.

14. In a fuel control valve for oil burners, a valve casing 'having a vertical cylindrical control 4passage and a plurality of vertically staggered outlet passages communicating with said control passage, and a temperature responsive cylindrical plunger movable in said control passage having an annular groove intermediate its ends forming a lower control portion movable across said outlet passages to vary progressively the cross section of said outlet passages, said casing also having an inlet passage communicating with said control passage in all positions of said plunger, and said plunger having a passage communicating with said inlet passage and with said groove.

15. In combination, an oil burner including a burner base having adjacent loW and high heat burner grooves, means for supplying oil separately to said grooves including temperature responsive valve means governing the admission of oil successively to said low and high heat grooves, first gradually increasing the amount of oil supplied to said low heat groove to an amount closely approaching the maximum amount which can be consumed therein and admitting oil to said high heat groove in gradually increasing amounts until both burner grooves are supplied with the maximum amount of oil which they can consume without smoking, and means for igniting the fuel in said high heat groove from the ame in said low heat groove as oil is supplied to said high heat groove.

` LYNN O'I'IS SELBY.

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