US2329473A

US2329473A - Heating apparatus

Info

Publication number: US2329473A
Application number: US322414A
Authority: US
Inventors: Walter S Landon
Original assignee: Detroit Lubricator Co
Current assignee: Detroit Lubricator Co
Priority date: 1940-03-05
Filing date: 1940-03-05
Publication date: 1943-09-14
Anticipated expiration: 1960-09-14

Description

Sept; 14, 1943. w. s. LANDON HEATING APPARATUS Filed March 5, 1940 5 Sheets-Sheet 1 INVENTOR W066i. A]. Maw

11w mu,

Sept. 14, 1943.

w. s. LANDON gmnm APPARATUS 'Filed March-5, 1940 5, Sheets-Sheet 2 I l l l I I l I l l l l .4 I l l I Fla-3 & e aw 4| I 45 INVENTOR 46 25 M K M A45) AT row-Ev" W. S. LANDON HEATING APPARATUS Filed March 5, 1940 Sept. 14, 1943.

5 Sheets-Sheet 4- nU m Sept. 14, 1943. w. s. LANDON HEATING APPARATUS Filed March 5, 1940 5 Sheets-Sheet 5 INVENTOR Patented Sept. 14, 1943 UNITED STATES PATENT OFFICE HEATING APPARATUS Walter S. Landon, Detroit, Mich, asslgnor to Detroit Lubrlcator Company, Detroit, Mich. a corporation of Michigan Application March 5, 1940, Serial No. 322,414

15 Claims.

My invention relates generally to heating apparatus and more particularly to apparatus for controlling the flow of liquid fuel to a hydroxyla- A further object is to provide an apparatus which acts to provide natural draft flow of air to the burner upon failure of the forced air supplying means. 1

A further object is to provide means for interconnecting the air controlling means with the fuel controlling means to provide at all times the correct proportion of fuel and air to the burner.

The invention consists in the novel arrangement and construction of the parts to be more fullydescribed hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.v

In the accompanying drawings, to be taken as a part of this specification, I have fully and clearly illustrated a preferred embodiment of my invention, in which drawings:

Figure 1 is a schematic view of a heating system employing a liquid fuel burner and showing my control apparatus and. the control system therefor;

Fig.2 is a top plan view of the control apparatus with certain of the parts removed in order to show more clearly a portion of the controlling means and showing a simplified control circuit therefor;

Fig. 3 is a front view in elevation of the apparatus with a portion of the fuel controlling means in vertical section;

Fig. 4 is a view substantially along the line 4-4 of Fig. 2 looking in the direction of the arrows;

Fig. 5 is a view substantially along the line 5--5 of Fig. 2 looking in the. direction of the arrows;

Fig. 6 is a schematic view of a modified form of a heating system showing my burner control apparatus in conjunction with a modified fluid control system;

Fig. '7 isa view in central vertical section of the space temperature sensitive element of Fig. 6 and showing the adjusting means;

Fig. 8 is a view of the modified control apparatus of Fig. 6 taken in central vertical section through the control chamber, the fuel chamber and the power element and also aview showing in elevation the control system bulb means;

Fig. 9 is a top plan view of a modified form of the controlling apparatus;

Fig. 10 is a view substantially along the line l0|ll of Fig. 9 looking in the direction of the arrows and with the fuel chamber partly broken away and partly shown in section, and

Fig, 11 is a view substantially along the line H--ll of Fig. 9 looking in the direction of the arrows with the control chamber and fuel chamber removed but showing the air supplying means connected thereto.

Referring to the drawings -by-characters of reference, the numeral I indicates generally a heating apparatus for a hydroxylation type burner 2 to be supplied by. fuel and air through conduits .2 and 2 respectively, leading from a control device 3. The products of combustion from the burner 2 pass upwardly into the combustion chamber 4 and outwardly therefrom through a central aperture 4 of the chamber 4 and pass downwardlybetween the outer wall of the combustion chamber 4 and a shell 5 which separates the products of combustion from but transfers the heat to the air within a plenum chamber 6. The spent combustion products then pass .to atmosphere througha stack 6 which is controlled by means of a damper 8'. A constantly operating air circulating fan I is driven by an electric motor 8, connected thereto by means of a pulley and belt drive 9 and extracts air from the space H) to be heated through an outlet duct means H which leads to a fan inlet chamber l2. Air is forced outwardly by the fan 1 through a duct l3 into the furnace plenum chamber 6 where it is heated due to its contact with the heated furnace shell 5 and flows therefrom through a duct Hi to the space It).

The operation of the burner 2 is controlled by means of a unique room thermostat, diagrammatically shown at IT, and described in detail hereinafter. The thermostat ll acts to maintain a predetermined temperature within the space l0. Excess heating of the plenum chamber 6 is prevented by. means of the usualhigh tempera-. ture limitcontrol l8 which acts tii reduce the fuel flow to the burner 2 upon occutrence' of a predeterminedhigh temperature in the chamber 6 to prevent overheating thereof. Fuel oil is stored in an oil tank I9, and flows therefrom through a conduit 19, and through a constant level device IQ, and through the conduit 20, to the control means 3. The fuel oil is metered by the control means 3 and flows therefrom through the conduit 2 to the fire pot 2|. The necessary air for combustion of the fuel oil is supplied by the fan 1 and flows through a conduit 22 which opens into the duct l3 through an orifice 23 and leads to the control means 3 where the .air is regulated in proportion to the quantity of fuel oil being supplied to the burner. The regulated air then flows through the airconduit 2 to the Positioned in one wall of the conduit 22 is an air pressure regulator or shutter'24 which acts to maintain a substantially constant air pressure within the conduit 22 at all times. Should the pressure within the conduit begin to exceed the predetermined desired pressure, the shutter 24 will open to allow the excess air to escape and should the pressure begin to decrease below atmospheric pressure, the shutter 24 will open to allow atmospheric pressure within the conduit 22.

The control means 3 preferably comprises a chambered housing or hollow casing member 25 having a chamber 26, with an inlet 21 connected to the conduit 22, and an outlet 28 connected with the conduit 2 (see Fig. 1).' Flow through the chamber 26 is controlled by a plate-like shutter 29 positioned within the chamber 26. The top portion of the shutter 29 is rigidly secured to a shaft 29, spaced from but positioned adjacent the top wall of the chamber 26 and which is journalled at either end in

opposite end walls

36, 3|

of the chamber 26. The shutter 29 when inert hangs downward acros the inlet 21 and normally acts to close the inlet 21 to flow of air but is urged in an open direction (see Fig. by the pressure of the air within the conduit 22. The shutter 29 preferabl has a large aperture 32 therethrough. A pair of ears 33 (only one of which thereof. Substantially midway betweenthe bottom wall 4| and the top wall 40, the

side walls

36, 42, 43 and 44 have an upwardly facing shoulder 59 against which is positioned a plate-like member 5|. The member 5| ha an aperture through which the valve stem portion 49 projects and in which the valve member 41 is guided in its reciprocal movement. The

side walls

30, 42, 43 and -44 also have a second upwardly facing shoulder 62 positioned below the top wall 48 and above the shoulder 50 and against which is positioned a plate-like member 53. The member 53 is apertured to receive and guide a reduced stem portion -54 of the valve stem portion 49. The plate-like member 5|, 53 cooperate to divide the chamber 39 into a plurality of

smaller chambers

55, 56

, and 51, chamber 55 being the bottom or fuel oil is shown) are bent toward the inlet 21 from the shutter 29, one adjacent each of the aperture 32 side edges and both adjacent the aperture 32 bottom edge. The ears 33 have aligned apertures" therein for receiving a shaft 34. A second platelike shutter 35 overlies the aperture 32 of the shutter 29 on the inlet'21 side thereof and has a pair of ears 36 projecting from its side edges and adjacent its bottom edge (only one of which is shown). The ears 36 have aligned apertures through which the shaft 34 extends so that the shutter 35 is pivotally carried by the shutter 29. A bolt-like threaded member 31 is secured to the shutter 35 adjacent its upper edge portion and extends toward the inlet 21. A nut-like weight member 38 is threaded on member 31 and biases the shutter 35 in an opening direction to open the aperture 32 for flow of air. The member 38 may be moved back and forth to determine the biasing of the shutter 35. The shutter 35 is held in its position against the shutter 29 by the pressure of the air .within the conduit 22. Should the air pressure fall below a predetermined minimum,

the weight'member 38 will pivot the shutter 35 is separated therefrom by the wall 30. The chamber 39 has an open top wall 40, a bottom wall 4|, and

side walls

42, 43, 44 in addition to the common wall 36. The chamber 39 is supplied with fuel oil by the conduit 26 which is connected to a chamber inlet 45 openin through the side wall 42. adjacent the bottom wall 4|. The chamber 39 ha an outlet 46 positioned in and extending from the bottom wall 4| for connection with the conduit 2*. Flow through the outlet 46 is controlled by means of a valve member 41 which cooperates with a valve port 48 in the outlet 46. The valve member 41 has an extending valve stem portion 49 which projects upwardly through the chamber 39 substantially parallel to the si e Walls chamber, chamber 56 being the intermediate or power element chamber, and chamber 51 being the top or adjustment chamber. The valve stem portion 49 is drilled concentrically with it longitudinal axes to form a passageway 58 which opens at its lower end below'the valve port- 48 and connects at its upper end with a radially drilled hole 59 which communicates with the upper portion of the chamber 55, above the substantially constant fuel level maintained therein by the con- 7 stant level device l9. A passageway 66, in a boss integral with the wall 43, ha dts lower end opening into the outlet 46 audits upper end opening through the shoulder 50 in alignment with an aperture through the member 5|. The member 53 has an aperture or drilled hole 6| there'- through for maintaining the chamber 56 at atmosphericpressure. The

passageways

58, 60 and

drilled'holes

59, 6| cooperate together to form a vent for the space within chamber 55 overlyingthe liquid and also a vent for the outlet 46 so that the outlet on the conduit 2 side of the valve port 48 will always be maintained at atmospheric pressure. By maintaining atmospheric pressure in chamber 55 and in conduit 2 any relative variations in height between the control device 3 and the burner 2 does not affect the fuel flow through the valve port 48. The plate-like member 53 has a pair of threaded apertures in which are threadedly secured a pair of adjustably threaded stop members 64, 65 respectively. The stop member 64, 65 have at their lower end portions,

flanges

66, 61 which cooperate respectively with upper and lower surfaces of an annular flange 68 of the reduced stem portion 54 to limit opening and closing movement of the valve member 41. The stop member 65 may be set for any fuel flow which will burn with natural draft or air supplied at atmospheric pressure to the burner 2. It must be remembered, however, that the stop member 65 adjust the minimum burner operation and the burner 2 will therefore never operate to supply less heat even though the thermostat l1 be in a satisfied position. The stop member 65 therefore should be properly adjusted so that when the burner 2 is operating at minimum flow conditions it will not overheat the space i6.

The shaft 29' has a portion 69 which extends into the chamber 39 and more particularly into the power element chamber 56. The extendine portion has rigidly secured thereto one end of a crank arm 10 which terminates in an end portion 1| The side wall 44 is slotted, as at 1|; to provide clearance for the arm 10. A bos 12 projects from the wall 30 into the power element chamber 56 and adjacent the wall 42. A fulcrum pin 13 1s rotatably carried within an aperture extending through the boss 12 and the wall 36 and substantially parallel to the wall 30 and terminates in a bifurcated end portion 16 which receives the end portion H of the crank arm carried by the shaft 29. A circular portion of the lever member is positioned intermediate the bifurcated end portion 16 and the pivoted end portion 14 and is positioned between the annular flange .68 and a second flange 11 which, like annular flange 68, extends outwardly from the reducedstem portion 54 of the valve member 41 and which is spaced from and below the annular flange '68.

Positioned in the chamber 56 and secured to the side wall 42 thereof is one end of a supporting member 18 which carries at its other end the bimetallic element 19. The bimetallic element 19 is hook-shaped and has a cylindrical portion 80 with a longitudinally split side wall. One edgeportion 8| of the split is secured to the supporting member 18 and the other edge portion has a radially outwardly extending lip 82. An electrical heater means 83 is positioned within the portion 80 in heat exchange relation therewith and acts upon energization thereof to heat the portion 80 so that it tends to open up and to raise the lip 82. The lip 82 normally engages the upper face of a shoulder 84 formed on the valve stem portion 49 at the intersection of the normal diameter portion with the reduced diameter port on and limits upward movement of the valve member 41. The heater means 83' is preferably of large mass so that it has a slow rate of temperature change and acts to heat the portion 80, in response'to the average time the heater means is energized, rather than being responsive to heat the portion only when the heater means is actually energized. The heater means 83 has lead wires '85, 85 which extend therefrom and terminate at binding posts 86, 81 which are carried by a terminal block88. The block 88 is mounted,

as by screws, to the outside of the wall 42' and spaced therefrom by a spacer means 89.

Air pressure in the inlet 21 acts on the

shutters

29, 35 to rotate the shaft 29 in a clockwise direction (see Fig. 4). Clockwise movement of the shaft 29 acts through the crank arm 10 to rotate the lever member 15 in a counter-clockwise direction. Rotation of the lever member 15 in the counter-clockwise direction acts to move the valve member 41 upward from the valve port 48 to allow greater flow of fluid from the chamber to the burner 2. Upward movement of the valve member 41 is limited by engagement of the shoulder 94 with the lip 82, and the lip 82 acts as a variable stop to limit the flow of fuel oil and air to the burner in accordance with the temperature of the Space I0 as reflected by the thermostat l1.

The room thermostat I1 comprises a bimetallic responsive blade 90 which carries a contact member 9I cooperable with a fixed contact member 92 to control an electric circuit in response to changes in temperature of the blade 90. Electrical energy from a suitable source of supply is conducted to the primary terminals of a transformer 93 by means of lead wires 94; -The transformer 93 has a secondary coil terminating in

terminals

95,96. Lead wires'91 are directlyconnected to the lead wires 94 and to the electric motor'8 so that the motor 0 is supplied with electrical energy for continuous operation. The

bimetallic blade is connected by means of a lead wire '98 to one terminal of the transformer 93. The fixed contact member 92 is connected, by means of a lead wire 99, to one binding post 96 of the control device 3. The other bindin post 81 of the control device 3 is connected by means of a lead wire I00 to one side of the limit switch I8 which has its temperature sensitive element located within and sensitive to the temperatures of air in the plenum chamber 6.. The

other terminal of the limit switch I8 is connected by means of a lead wire I0I to the ter-' minal 96 of the transformer 93. The thermostat I1 also includes a resistance heater element I02 which acts upon energization to heat the bimetallic blade 90 to cause the contact member 9|,.

92 to separate and break th electrical circuit controlled thereby. The heater element I02, un-

like the heater means 83, is one having a small mass so that it is quickly heated and cooled and heats the blade 90 more n arly in direct accordance to its energization or at a given predetermined rate. One terminal of the heater I02 is directly connected to the contact member 92 and the other terminal of the heater I02 is connected by means of a lead wire I03'to the terminal 96 of the transformer 93. The thermostat I1 is preferably so constructed that the bimetallic blade 90 is operable to close the contact members 9 I 92 at a minimum predetermined temperature and to open the contact members 9|, 92 ata maximum predetermined temperature and the difference between the maximum predetermined temperature and the minimumpredetermined temperature is the differential temperature of the thermo stat I1. The heater I02 is so chosen that it will act upon continuous energization to heat the bimetallic blade 90 to a predetermined temperature above the surrounding air temperatur and which predetermined temperature is greater than the differential temperature of the thermostat I1. Due to the effect of the heater I02, the-blade 90 is made to part the contact members 9I, 92 in a cycling manner until the temperature of the surrounding air reaches or exceeds the minimum predetermined temperature at which the blade 90 will move the contact members 9|, 92 into circuit closed position. By so constructing and arranging the heater I02, the heater means 83 and the blade 90; the thermostat acts in effect to modulate the flow of fuel and air tothe burner in accordance with the heating requirement thereof.

The operation of the burner apparatus may best be seen by giving an example. Assume that the cut-in or the minimum predetermined temperature at which the blade 90 moves contact members 9|, 92 together is 705 F. and the cutout or the maximum predetermined temperature at which the blade 90 moves contact members 9I, 92 apart is 72 F. The differential of operation is therefore 2 F. The heater I02 is so positioned and arranged relative to blade 90 that it will raise the temperature thereof the entire 2 F. in five minutes. Thus when the space I0 temperature lowers to 70 F. the blade 90 closes contact members 9|, 92 energizing heater I02 and heater means 83. Without rise in the temperature of the space I0, the heater I02 would act, at the end of five minutes, to part the contact members 9I, 92 and with temperature rise in space I 0, the time would be somewhat shortened. In the five minutes or less interim, however, the heater means 83 will have increased somewhat in temperature and heated the portion'80 of the element 19,

This heating will'cause the lip 82 to move upward slightly so that the air pressure in the conduit 22 will act to move the

shutters

29, 35 to allow an increased flow of air to the burner. Movement of the shutter 20 acts through shaft 29. crank arm and levermember to open the valve member 41 in proportion to the rate of increase in the supplied air. The lip 82, however, still continues to act as a stop and limits the increased flow in proportion to the heating efiect imparted to the cylindrical portion 80 by the heater means 83.

Returning again to the action of the thermostat, the contact members SI, 92, having deenergized the circuit to the heater I02, the blade 90 cools rapidly, say in five minutes, and the blade 90 is again subject to the temperature of the space I0. If the heating eifect of the burner 2 was sufficient to raise the space I0 temperature above 70 F., the contact members 9|, 92 remain parted. If, however, not enough heat has been supplied, the contact members 9|, 92 will be moved together again by the blade 90 and the heater means will be given again a period of heating. If the space temperature dropped to say 67 F. and the heater I02 was designed to raise the temperature of the blade only 4 F. on continuous energization, the blade would be maintained at 71 F. and the heater means 83 would remain constantly energized so that after a given time the lip 82 of element 19 will raise and allow the air pressure within conduit 22 to move the

shutters

29, 35 and valve member 41 until the flange 68 engages the flange 66 of the stop member 64 at which time the burner is operating at maximum flow capacity. Under the cycling conditions, however, the heater means 83 is getting little bumps of heat and maintains an average temperature intermediate the maximum temperature and that of the surrounding media. After a prolonged period of deenergization, however, the heater means 83 will cool and the lip 82 will lower to move the valve member 41 until the flange 68 engages the flange 61 of the stop member 65 at which time the burner 2 is operating at minimum flre condition.

Should, however, the air pressure fall within the conduit 22 for any reason such as pluggin of the orifice 23 or failure of the fan 1, the shutter 35 will fall forward due to the biasing effect of the weight member 38 to open the aperture 32 and the shutter 24 will open so that air under natural draft will flow to the burner 2. As the air pressure acting on the

shutters

29, 35 is the sole means of opening the valve member 41,- the valve member 41 will remain against the minimum fire stop member 65 irrespective of the heating of the element 19 by the heater means 83. There is, therefore, no danger of the burner 2 being flooded with fuel oil and burning with a sooty flame or of causing an explosion. It may therefore be seen that. the burner apparatus is operable to modulate the heating effect in accordance to the demand by the space to be heated; will accurately proportion the relative amounts of air and fuel to maintain at all times the proper fuel-air mixture; requires no additional fan motor for supplying the burner; and will automatically go to minimum flow natural draft conditions upon failure of the air pressure.

The circuit which is shown in Fig. 2 is diagrammatically that which is shown in Fig. 1 with the exception that the limit control has been omitted.

Figs. 6, 1 and 8 show ajmodified'form of the control system in which a fluid control has been used in place of the electrical control. For simplicity a natural convection heating furnace has been shown but this fluid control could be used in a forced convection heating installation with equal ease and,-if so used, the air circulating fan could be used to furnish air to the burner, as in Fig. 1, instead of a. fan means I 05 as shown. The parts of Figs. 6, 'l and 8, which are substantially the same as the parts in the preceding figures,

are designated by the same reference characters.

In keeping with the showing of a natural con.- vection heating system, the outlet duct means II of the space I0 is connected directly to g the plenum chamber 6 in place of the duct I3. The fan means I05 supplies air under constant pressure through a duct means I06 to the inlet 21 of the control device 3. The control device 3 is operated by the fluid control system which comprises a thermostat I01 positioned in and sensitive to the temperature within the space I0, a pressure sensitive power element I08 operatively connected to the control device 3 and a pressure generating bulb means I08 which is positioned in heat exchange relation with the bottom wall IIO of the fuel burner fire pot 2I. The thermostat I01, element I08, and means I08 are communicatively connected together by a conduit means I I I.

The thermostat I01 comprises a cylindrical casing including a chamber I I2 having a side wall II 3, and a lower end wall or bottomwall H5. The bottom wall II5 has an aperture therethrough in which is sealed in fluid-tight relation one open end portion of the conduit means III for communication with the chamber H2. The side wall II 3 has an aperture II6 therethrough and the side wall II3 has a boss II1 projecting inwardly into the chamber II2 diametrically opposite and in alignment with the aperture II6. A bellows member II 8 has one end portion secured in fluid-tight relation, as at I I9, to the wall II3 around the peripheral edge .of the aperture H6. The other end of the bellows member II 8 projects within the chamber H2 and is sealed in fluid-tight relation to an end member I20. A closure member I2I overlies the aperture H6 and is held in fluid-tight relationship to the exterior surface of the wall II3 by solder I2I The bellows member H0 and end member I20 cooperate to make the chamber II 2 a variable volume receptacle communicating with the conduit means III through the bottom wall I I5. The volume of the chamber H2 is controlled by means of an adjustment screw I22 which is threadedly received in an aperture throughthe closure member I2I. The screw I22 has a head portion I23 external of the closure member I 2I which may be manually gripped for rotation of the screw I22 to adjust the volume of chamber II2. If desired, an indicator may be secured to the screw I 22 and suitable indicia carried by the wall II3 to indicate the setting of the screw I22. The other end I24 of the screw I22 extends within a space I25 defined by the bellows member II8, closure member I2I,- and end member I 20, The end I24 is rounded and engages the end member I20 to hold it against movement due to the compression force of a helical coil compression spring I26 which is held under compression between the wall II 3 and end member I20. The spring I26 has its end portions surrounding and held in position by the boss H1 and a boss I21 on the end member I20. The spring I26 acts to maintain the end member I20 at all times in engagement with the end I24, and

needs to exert a greater force than the innate resilient force of the bellows member [I8 so that as the screw I22 is moved inward into the space I25, the bellows II8 will expand and upon outward movement of the screw I22 the bellows will compress.

A second portion of the conduit means III is sealed in fluid-tight relation to an aperture in the bottom wall of a cup-shaped casing I28 of the power element I08 and is in communication with the interior thereof. The power element I08 comprises the casing I23 which has an out-turned flange portion I29 secured to the wall 42 of the control device 3, a bellows member I30 and a thrust member I3 I. One end portion of the bellows member I30 is sealed in fluid-tight relationship to the inner peripheral edge of an annular ring member I32 which has its outer periphery sealed in fluid-tight relationship to the inner wall of the cup-shaped casing I28 adjacent the open end thereof. The other end of the bellows member I30 extends inwardly into the casing I26 toward the bottom wall thereof and is sealed in fluid-tight relationship to an end member I33. The casing I28, bellows member I30, end member I 33 and ring member I32 cooperate to form a sealed pressure responsive chamber I34. The thrust member I3I comprises a cylindrical member I35 having a concentric bore I36 therethrough. A portion I31 of the bore I36 is of enlarged diameter and opens through one end of the member I35. A rod-like thrust member I31 is reciprocal within and fits within the bore I36 and has one end portion extending beyond the member I35 and secured to the end member I33. The other end of the rod-like member I31 extends into the enlarged diameter bore portion I31 and has a head portion I38 which is operable to reciprocate within the portion I31 but is urged against a shoulder formed at the intersection of the enlarged diameter bore portion I31 and the normal diameter of the bore I36 by a helicalcoil compression spring I39, which spring I39 is also positioned within the bore portion I31.

The spring I39 is held under compression and against the head portion I38 by an abutment member I40 threaded into the open end of the enlarged diameter bore portion I31. A conical end portion I4I of the member I40 extends beyond the cylindrical member I35 and is received within a conical recess I42 of a vertically extending arm I43 of a bell-crank lever member I44 pivoted, as at I45, to a bos I46 which extends outwardly from the chamber wall 30. The horizontal arm I41 01 the bell-crank lever member I44 abuts the upper face of the shoulder 84 of the valve member 41 and acts to limit upward movement thereof similarly to the lip 82 of the bimetallic element (shown in Fig.4). The spring I39 holds the head portion I38 against the shoul-' der with a force greater than any normal force exerted by the power element I08 so that normally the thrust member I3I acts as a rigid member but which upon abnormal pressure ex- ,erted by the power element I08 acts to collapse to relieve the pressure within the chamber I34 without a corresponding movement of the lever member I44. The power element I08 also includes a helical coil compression spring I48 positioned within the bellows member I30 surrounding and concentric with the member I3I, One end of the spring I48 abuts the end member I33 and its other end abuts the outer surface of the wall 42. The spring I43 acts to oppose collapsing movement of the bellows member I30 in its movement of the valve member 41 toward closed position. I

A third portion of the conduit means III is communicatively conhected to the bulb means I09 and which bulb means acts to provide the pressure for the control system. The bulb means I09 is positioned within a well I49 of a heat conducting member I49 which has a portion secured in heat exchange relation with the bottom wall I I0 of the lite pot 2I.

The chamber II2, power element I08 and the conduit means III is at all times maintained substantially completely: filled with a temperature sensitive volatile liquid, the pressure of which is controlled by the bulb means I09 as will be described hereinafter. There being substantially no flow through the system thevapor pressure pressure within the inlet 21 of the control device 3 as the shutters 29, approach closed position, additional pressure in bulb means I09 is necessary as the valve member 41 approaches minimumflow condition. It will also be noted that as the bellow I30 collapses, the chamber I34 increases in volume which will tend to allow fluid to escape from the bulb means I09 to decrease the pressure therein. The final system pressure and position of the power element I08 will be a position of equalization of pressure within the means I09 and element I08.

The operation of the control system is as follows: As the liquid within chamber II2 increases in volume with increase in its temperature due to increasing temperature within the space I0, a quantity of. the liquid is forced from the conduit means III into the bulb means I09 where it is vaporized by the heat conducted to the bulb means I09 through the member I49. This will increase the pressure within the bulb means I09 and be transmitted to the liquid in the conduit means II and chambers H2 and I34. Increased pressure within the chamber I34 causes the end member I33 to compress the spring I48 to move the thrust member I3I to rotate the bell-crank member I44 in a clockwise direction (see Fi 8) until a balance of force again occurs as was set forth hereinbefore. Additional rise in temperature of the liquid within chamber I I2 causes 3 additional liquid to be elected from the conduit means III into the bulb means I99 to increase the pressure acting .on the liquid in the conduit means III and chambers II2, I34.

Upon cooling of the chamber II2 liquid is received therein from the conduit means I II which allows fluid to escape from the bulb means I09 thereby lowering the pressure within the bulb means I09 and the chambers II2, I34 so that the

shutters

29, 35 and the valve member 41 can open. The expansion and contraction of the liquid in the chamber H2 is very gradual and continuous and it, therefore, may readily be seen that the valve member 41 will be modulated throughout its range of movement to decrease and increase the output of burner 2 in response to change in temperature of the space I0.

'bottom wall I65 of the chamber ISI.

Should the adjustment screw I22 be rotated manually throughout its range in a temperature lowering direction, considerable liquid will be ejected from the conduit means III into the bulb means I09 due to the decrease in volume of chamber II2. Because of the large amount of liquid ejected into the means I09 and the restricted rate of flow of heat to the bulb means I09 through the member I49 it will take considerable time to vaporize the liquid to increase the pressure enough to move the valve member 41 and

shutters

29, 35 to closed position. This lag should preferably be sufficiently great so that the valve member 41 and

shutters

29, 35 will slowly move toward closed position possibly taking two minutes or longer thereby to prevent a smoky flame which results from immediately stopping the flow of air before the fuel pool in the pot 2I is consumed.

The operation of the apparatus shown in Figs. 6, 7 and 8 is substantially the same as explained in respect to the preceding flgures except for the change in the air supplying means, and the control system, as set forth hereinbefore, and a further description is deemed unnecessary.

In Figs. 9, 10 and 11 there is shown a modification of my device in which the mechanical interconnection between the air controlling means and the fuel controlling means is maintained but instead of the continuously throttling type of fuel control there is shown an apparatus which modulates the output in steps. A chambered casing I 50 has an upper or control chamber II, a lower or constant level fuel oil chamber I52 positioned below the control chamber I5I and an air flow passageway or chamber I53 which is positioned above the constant level chamber I52 and beside of the chamber I5I, with a wall I54 in common with the chamber I 5I. A plate-like supporting member I55 for the modified control apparatus, to :be hereinafter described, is positioned within the chamber I5I and has a plurality of upturned flanges or supporting portions I56, I51 from its side edges and has flange portions I58, I59 extending upwardly from its end edge portions. The flange portions I56, I51 are respectively secured to the protuberances I60, I6I projecting inwardly from side walls I62, I63,of the chamber I5I by suitable means, such as screws. The end flange portion I59 is suitably secured to the common wall I54 and holds the bottom portion I64 of the plate-like supporting member I55 in a substantially horizontal position parallel to a The wall I54 and end flanges I58, I59 have aligned aper- .tures in which a shaft I66 is journaled for rotational movement. A portion I51 of the shaft I66 extends into the chamber or air flow passageway I53 and rigidly carries a cam member I68 for cooperation with one face of a butterfly damper or shutter I69, pivoted at its upper edge portion, as at I10, to the top wall "I of the chamber I53. The shutter I69 is biased toward open position by a helical coil tension spring I12 which has one end rigidly secured, as at I13, to the top chamber wall I1I of the chamber l53 and which has its other end secured, as at I14, to the face of the shutter I69 opposite to that engaged by the cam member I69. The chamber I53 has open end walls I15, I16 and the open end I16 is connected to the inlet side of a fan or air supply means I19 which is used to supply air to the fuel burning apparatus, such as the fuel burner 2 (shown in Fig. l) The open end wall I15 may be opened to and subjected to atmospheric pressure so that when the fan means I18 is in operation the atmospheric pressure acts on the shutter I69 and urges it against the force of the helical coil spring I12 toward closed position. Referring again to the chamber I5I and the platelike supporting member I55, it will be seen that the bottom portion I64 has a pair of upturned fingers I19, I90 which carry a medium fire and a high flre bimetallic power element 'I8I, I92 respectively and which elements are preferably hook-shaped in form and have cylindrical portions I93, I94 respectively. The portions I93, I84 are longitudinally split to form side wall end portions I95, I85 and I81, I88 respectively. Lip or power transmitting portions I91, I98, respectively, extend radially outward from portions I91, I89. The end portions I85, I96 are secured to the fingers I 19, I and support the bimetallic power elements I81, I92 rigidly with the member I55.

A valve member I99, positioned within chamber the conduit 2 for controlling the flow of fueloil to the burner 2. The valve member I99 has a stem portion I9I which projects upwardly from the chamber I52 through an aperture in the bottom wall I 65 into the chamber I5I and terminates in a reduced diameter end portion I92. This portion I92 is guided i'or reciprocal movement with in an aperture extending through a protuberance or boss I93 projecting inwardly from the side wall I62. The reduced diameter end portion I92 has a pair pi spaced annular outwardly extendin flanges I94, I95. Screw-threaded within apertures in the protuberance I93 are a pair of stop members I96, I91 having flanges I99 (only one of which is shown) which cooperate with the under and upper surface of the flange I94 to limit reciprocal movement of the valve member I99 and controls the minimum and maximum flow of fuel oil to the burner 2. A third stop memberv I99 is threadedly secured to a plate-like member 200 which is secured by means of a screw to a protuberance 20I which projects inwardly within the chamber I 5| from the wall I54. The lip portion I91" upon its upward movement engages the stop member I99 which limits the upward movement of portion I91 and its lip portion I91 to determine the intermediate flre operation. The high flre bimetallic element I 92 is operatively connected to the shaft I66 for movement thereby in one direction by a,lever member 202 rigidly secured to the shaft I66 and which has'an extending arm portion 203 operable to engage the upper surface of the element lip portion I99. A second lever member 204 is pivotally connected to the shaft I66 and has an arm portion 205 which is received intermediate the flanges'l94, I95 and has a second Portion 205 which overlies a portion 205'" 'of the lever member 202. The lever member 204 is connected to the lever member 202 by an adjustment mechanism comprising a threaded screw 206 which is loosely received within an aperture in the-lever member portion 205" and is threaded within an aperture in lever member portion 205*. A helical coil compression spring 201 surrounds the screw 209 and is placed under compression between the lever member portions 205, 205 and acts to urge the lever member portion 205 against the head of the screw 206. The bimetallic power elements I9I, I92 are actuated by a pair'of

electric heating units

209, 209 positioned within the cylindrical portions I93, I94 respectively, .of the bimetallic elements I8I, I92. The

units

208, 209 act to heat the bimetallic elements so that the portions I83, I84 will open up thereby moving the lip portions I81, I88 in an upward direction. Upon upward movement of the lip portion I81 it engages the underside of the flange I95 to lift the valve member in an opening direction and is limited in its movement by the engagement of the lip portion I81 with the lower end of the stop member I99. Upward movement of the valve member, due to the positioning of the arm portion 205 of lever member 204 between the flanges I94, I95, acts to rotate the lever member in a clockwise direction (see Fig. 11) and the cam member I68 to coact with the face of the shutter I69 to force the shutter I69 against the air pressure in the passageway I53 to allow floWof air therethrough to the inlet of the fan means I18. By correctly proportioning the cam surface and the valve member I89, the relative flows of oil and air may be accurately controlled so that the correct proportion of each for proper combustion may be admitted to the fuel burner 2. Upon energlzation, the heating unit 209, which is the high fire heater, acts to heat the cylindrical portion I84 so that the lip portion I88 moves upward to engage the arm portion 203 of the lever member 202 to rotate the shaft I66 further in a clockwise direction. Further movement of theshaft I66 causes the shutter I69 to move to a further open position, and causes the valve member I 89'to move to a further open position to supply additional fuel corresponding to the additional air supplied to the fuel burner 2. The flange I95 will, under high fire conditions, be spaced above the lip portion I81. 3

The

heating units

208, 209 are electrically connected in the following manner: The unit 208 is connected by means of lead wires 2I0, 2 to binding posts 2I2, 2I3 respectively carried by a terminal strip 2I4 secured in a suitable manner externally of the chamber I5I to the side wall I63 and the unit 209 is connected by means of lead wires 2I5, 2I6 to the' binding post 2I3 and to a binding post 2I1 respectively, the binding post 2I1 being carried by the terminal strip 2I4. A transformer 2I8 has its primary coil connected by means of lead wires 2I9 to a source of electrical energy and has its secondary coil 220 connected to terminals 22I, 222. A lead wir 223 connects the terminal 222 to the binding post 2I3 so that oneside of the

heaters

208, 209 are connected directly to one side of the transformer secondary coil 220. The other terminal 22I of the transformer 2I8 is connected by means of a, lead wire 224 to a thermostat, diagrammatically shown at 225, and'which may be positioned within the space heated by the burner 2. The thermostat 225 comprises a bimetallic blade 226 which is directly connected to the lead wire 224, and which carries a pair of contact members 221, 228, the contact member 221 being secured to the blade by a spring member 221 and the contact member 228 being directly secured thereto.

The members 221, 228' cooperate respectively with a pair of

stationary contact members

229, 230. The contact members 221, 229 act to complete an electric circuit at a higher blade temperature than the blade temperature necessary to close the

contact members

228, 230. The contact member 229 is connected by means of a lead wire 23I to the binding post 2I2 and the contact member 280 is connected by means of a lead wire 232 to the binding post 2I I.

The operation of the modification in Figs. 9,.

and 11 is as follows: The fan means I18 is continually operating and the suction created thereby causes the atmospheric pressure to act on the shutter I69 to hold it in engagement with the cam member I68. If the thermostat 225 is satisfied or in open circuit condition, as shown, the shutter will be in nearly closed position, as shown in Fig. 11. Upon a decrease in temperature in the space and of the blade 226, the contact members 221, 229 will be moved into engagement. This closes an electrical circuit from the terminal 22I lead wire 224, blade 226, contact members221, 229, lead wire 23I, binding post 2I2, lead wire 2I0, heating unit 208, lead wire 2I I, binding post 2I3 and lead wire 223 to the terminal 222. Upon closure of this circuit the heating unit 208 heats the cylindrical portion I83 and the lip portion I81 will move upwardly lifting the valve member I89 until the lip portion I81 engages the stop member I99 which limits the opening movement. Upward movement of the valve member I89 acts through lever member 204 to rotate the shaft I66 and cam member I68 to move the shutter I69 against the force of the atmospheric pressure to allow for increased air flow to the burner 2 in proportion to the increased fuel oil flow. Should the burner output'not be suilicient to maintain the-space temperature and the temperature should fall to a predetermined lower temperature, the

contact members

228, 230 will engage. This energizes a second circuit from the terminal 22I through lead wire 224, blade 226, contact members 2281 230, lead wire 232, binding post 2I'I, lead wire 2I6, heating unit 209, lead wire 2I5, binding post 2I3, and lead wire 223 to the terminal 222. Energization of the heating unit 209 acts to heat the cylindrical portion I84 and thereby to move the lip portion I88 upward to engage the armportion 203. Continued upward movement of the portion I88- acts to move the lever member 202 to rotate the shaft I66. Rotation of the shaft acts through the arm portion 205 to lift the valve member until the flange l94 engages the stop flange I 98 of the stop member I91 to limit its 4 increased flow of fuel oil.

Upon opening of either of the sets of

contact members

228, 230 or 221, 229, the

connected heating units

209, or 208 respectively, will cool along with the cylindrical portions I84 or I83 so that the air pressure acting .on the shutter I69 will act through the cam member I68 to rotate the shaft I66 in a counterclockwise direction (see Fig. 11) thereby moving the shutter I69 and moving the valve member I89 toward closed position. It will, therefore, be seen that inthe modified form of thdapparatus the power elements act to open the valve and acts as astop to limit closing movement of the valve member and shutter by the air pressure in the chamber I53.

In case of failure of the air supplyingv means I18 the pressure across the shutter I69 will decrease and the spring I12 will move the shutter said burner, means for supplying air under pres-, sure to said burner, air pressure positioned damper means for controlling the flow of air to said burner from said supplying means, lever means mechanically interconnecting said fuel controlling means and said air controlling means, automatic means operable to control the positions of both said fuel controlling means and said air controlling means solely when said air'supplying means is effective thereby to maintain emcient operation of said burner, and means operable independently of said automatic. means for rendering said air controlling means ineffective to control the flow of air upon failure of said air "supplying means.

2. In an apparatus of the character described, a fluid fuel controlling means, an air flow controlling means, a shaft member, means interconnecting said fuel means and said shaft means, an abutment member connecting said shaft means and said air means, said air means being so positioned and related to the air pressure that said air means is held thereby against said abutment member, and means acting to urge said air means out of engagement with said abutment member and operable upon a predetermined low pressure of the air controlled by said air means.

3. In an apparatus of the character described, a fluid fuel controlling means, an air flow controlling means, a shaft means, means interconnecting said fuel means and said shaft means, an abutment member connecting said shaft means and said air means, said air means being so positioned and related to the air pressure that said air means is held thereby against said abutment member, means acting to urge said air means out of engagement with. saidabutment member and operable upon a predetermined low pressure of the aircontrolled by said air means, and power means acting on said fuel means to move said fuel means and said air means against the force of the air pressure.

4. In a device of the character described, a fuel supply chamber having an inlet and an outlet, a control chamber positioned above said supply chamber, a valve member controlling flow through said outlet and having a portion extending upwardly through said fuel chamber into said control chamber, an air controlling means, mechanical means interconnecting said valve member and said air means, a heat actuated thermostatic element positioned within said control chamber and operable to move said air controlling means in one direction, a heat actuated means within said control chamber, and lever means actuated by said heat actuated means and operable through said connecting means to move said air controlling means further in said one direction.

5. In a device of the character described, a fuel supply chamber having an inlet and an outlet, a control chamber positioned above said supply chamber, a valve member controlling flow through said outlet and having a portion extending upwardly through said fuel chamber into said control chamber, an air controlling means, mechanical means interconnecting said valve member and said air means, a heat actuated thermostatic element positioned within said control chamber and operable to move said air controlling means in one direction, a heat actuated means within said control chamber, lever means actuated by said; heat actuated means and operable through said connecting means to move said air controlling means further in said one direction, and means responsive to a condition of the air to render said heat actuated means ineffective to move said air 0on trolling means.

6. In a liquid fuel burner control apparatus, a constant level liquid fuel chamber having an outlet and having an inlet, a control chamber, a fuel valve controlling flow through said outlet and having a stem portion and having a projecting portion, stop means engageable by said projecting portion for limiting movement ofsaid valve in an opening direction, air controlling means for regulating the flow of air to the burner, mechanical means operable to control said air means and interconnecting said valve and said air means, said mechanical means being operable upon movement in one direction to move said valve in a closing direction, power means limiting movement of said mechanical means in said one direction, a heat actuated power element, and a lever member moved by said power element and operable to limit movement of said mechanical means in said one direction, said power element being operable through said lever member and said mechanical means to control said air means.

7. In a liquid flow burner control apparatus, a constant level liquid fuel chamber having an outlet and having an inlet, a control chamber overlying said fuel chamber, a fuel valve controlling flow through said outlet and having a stem portion extendinginto said control chamber and having a projecting portion; stopmeans engageable by said projecting portion for limiting movement of said valve in an opening direction, air controlling means for regulating the flow of air to the burner, mechanical means operable to control said air means and interconnecting said valve and said air means, said mechanical means including a lever member, said lever member being operable upon movement in one direction to move said valve in a closing direction, heat actuated power means limiting movement of said lever member in said one direction, stop means engageable by said power means to limit movement thereof upon energization, a heat actuated power element, a lever member moved by said power element and operable to limit movement of said first-named lever member in said one direction, said power element being operable through said second-named lever member and said mechanical means to control said air means, and means operable upon a condition corresponding to lack of air to render said power element ineffective to control said air means.

8. In a burner system for heating a space, a fuel control valve, means for moving said valve toward open position, a first fluid container positioned within and responsive to the temperature of the space, a second fluid container positioned in thermal relation with and responsive to the temperature of the burner, a pressure sensitive means having an operating element, means connecting said containers and said sensitive means to form a sealed interconnected system, a temperature sensitive volatile fluid within said system, said fluid being so related to said system that said connecting means and said first container and said pressure means are substantlally completely filled with liquid at all times, said fluid which is in said second container being so related thereto that all of said fluid may be in a vaporous state, the pressure of said vaporous fluid acting to determine the pressure of said fluid within said system, and means operatively connecting said operating element and said valve to limit movement thereof by said moving means in accordance with the pressure of said fluid within said second container.

9.'In a burner system for heating a space, a

fuel control valve, means for moving said valve toward open position, a flrst fluid container positioned within and responsive to the temperature of the space, a second fluid container, means having a predetermined rate of heat transfer for transmitting heat from the burner to said second container, a pressure sensitive means having an operating element, means connecting said containers and said sensitive means to form a sealed interconnected system, a temperature sensitive volatile fluid within said system, said fluid being so related to said system that said connecting means and said first container and said pressure means are substantially completely filled with liquid at all times, said fluid which is in said second container being so related thereto that all of said fluid may be in a vaporous state, the pressure of said vaporous fluid acting to determine the pressure of said fluid within said system, and means operatively connecting said operating element and said valve to limit movement of said fuel controlling means against the force exerted by said pressure responsive oxygen controlling means, and means for. rendering said sensitive means ineffective to actuate one of said controlling means upon a predetermined reduction in pressure of the oxygen available in said supplying means.

ment thereof by said moving means in accordance with the pressure of said fluid within said second container.

10. In a burner systemv for heating a space, a fuel control valve, means for moving said valve toward open position, a first fluid container positioned within and responsive to the temperature of the space, a second fluid container positioned in thermal relation with and responsive to the temperature of the burner, a pressure sensitive means having an operating element, means connecting said containers and said sensitive means to form a sealed interconnected system, a temperature sensitive volatile fluid within said system, said fluid being so related to said system that said connecting means and said first container and said pressure means are substantially completely filled with liquid at all times, said fluid which is in said second container being so related thereto that all of said fluid may be in a vaporous state, the pressure of said vaporous fluid acting to determine the pressure of said fluid within said system, means operatively connecting said-operating element and said valve' to limit movement thereof by said moving means inw accordance with the pressure ofsaid fluid within said second container, and means operable upon a predetermined abnormal pressure within said system to reduce said abnormal pressure.

11. In a fluid fuel control apparatus, a fluid fuel burner, means for controlling flow of fluid to said burner, means for supplying oxygen under pressure to said bumer, means for controlling the flow of oxygen and operable to exert a force proportional to the pressure of the oxygen, mechanical force transmitting means interconnecting said fuel controlling means and said oxygen controlling means and operable to maintain predetermined relative movement therebetween for proportioning the relative flow of the oxygen and flow of the fuel, saidv force transmitting means being operable to transmit the force of said oxygen controlling means to said fuel controlling means, means sensitive to the output of said burner and operable to regulate the move- 12. In an apparatus of the character described,

in combination a fuel flow controlling valve and an air flow controlling valve, means for establishing apressure differential across said air controlling valve, means interconnecting said valves and operable to provide predetermined relative movement therebetween, means for moving said valves toward open position, and means operable upon a predetermined reduction in said pressure differential for rendering said interconnecting means ineffective to maintain said predetermined relative movement.

13. In an oil burner control apparatus, a duct for flow of air to the burner, a pressure responsive air valve having an opening therethrough,

a pivoted valve plate closing said opening and movable to open position upon reduction of air pressure-said valve regulating the supply of air to the burner and eccentrically mounted within said duct to be urged toward open position due to the force of the air impinging thereon, means controlling flow of fuel to the burner; means interconnecting said air valve and said fuel controlling means so that movement of said air valve to supply more air to the burner acts to move said fuel controlling means to supply more fuel to the burner, and thermostatic means actuated in accordance with the output of the burner and mechanicallycooperating with said fuel means to determine the position to which said fuel means is movable by said air valve.

14. A fluid fuel burner control device comprising a casing having a passageway therethrough for flow of fluid fuel and having a passageway therethrough for flow of combustion supporting air, means for propelling air through said air passageway, a reciprocal fuel valve in said fuel passageway, an air valve responsive to air pressure and controlling air flow through said air passage, automatic means actuated in accordance with temperature change and operable to control the opening movement of said fuel valve, and means relating the position to which said air valve is moved by air pressure to the position to which said fuel valve is movable under the control of said automatic means.

15. A fluid fuel burner control device comprising a casing having a passageway therethrough for flow of fluid fuel and having a passageway therethrough for flow of combustion supporting air, means for propelling air through said air passageway, a reciprocal fuel valve in said fuel passageway, an air valve responsive to air pressure and controlling air flow through said air passage, automatic means actuated in accordance withtemperature change and operable to control the opening movement of 'said fuel valve, means relating the position to which said air valve is moved by air pressure to the position to which said fuel valve is movable under the control of said automatic means, and means cooperable with said air valve to establish an open air flow path through said air passageway upon failure of said propelling means.

WALTER S. LANDON.