USRE22068E

USRE22068E - Fuel burner control system

Info

Publication number: USRE22068E
Authority: US
Publication date: 1942-04-14

Description

, April 14, 1942. F. D. JOESTING 22.068

FUEL BURNER CONTROL SYSTEM I Original Filed June 27, 1936 /2 Sheets-Sheet 1 102 9899- 7/ I 7o 50 I [0O 75 5a 6' /29 77 35 6 If; i; 63 /25 I28 gr; -2 62 /27 nvvfi/vroe a) 1/15 ArraEr/EY April 14, 1942. F. D. JOESTING 22.068

FUEL' BURNER CONTROL SYSTEM Original Filed June 27, 1936 2 Sheets-Sheet 2 k 'IIIIIIII.

er lf/S Ar oe/v pilot burner trolled by a control valve, wherein means are provided for closing both the Reissues! Apr. 14, 1942 p Re. 22,068

roar. uma oou'mon srs'rnu Frederick D. Joestlng, Chicago, 111., asslgnor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Original No.

No. 87 ,716, June 27, 1938.

amuse, dated May :1, 193:, Serial Application for reissue May 29, 1940, Serial No. 337,930

2'! Claims.

My invention relates to a fuel burner control system and .more particularly to one employing means for interrupting the supply of fuel to the main burner in the event of the pilot burner being extinguished.

It is customary with certain types of fuel burner control systems to employ a constantly burnlng pilot for ignitng the fuel supplied to the main burner. Where such a pilot is employed, some means is usually provided for preventing fuel from being supplied to the main burner in the event that the pilot burner is extinguished. Such a means is commonly referred to as a safety pilot. The safety pilot arrangement may take any of various forms. It may operate directly through a valve in the main fuel line or it may operate through a control device such as a valve or switch, which in turn controls the operation of a main fuel valve which is normally controlled by some controlling condition. In certain of these systems, it is. also common to provide a valve which controls the flow of gas to the pilot burner and is-under the control of the safety arrangement so that in the event of the being extinguished, the supply of fuel to both the pilot burner and the main burner is interrupted. The present invention,

pilot type of system.

An object of the present invention is to provide a novel fuel burner control system employing a pressure motor operated main valve which is conpilot and main valves in the event of the pilot burner being extinguished and wherein means are provided for first opening the pilot valve while positively holding the control valve in a position causing the main valve to be closed and, then upon the pilot burner being lighted, moving the control valve to a position causing opening of the main valve.

A further object of the present invention is to provide a novel arrangement for the operation of two valves which are to be operated succes- 'sively, the second being opened'only after a predetermined condition has been established as the result of the operation of the first valve.

A further obiect of the present invention is to I provide a novel safety pilot arrangement emplcying a thermocouple which is located in the path of the ilot flame and controls the opening and closing of a control valve of a pressure motor operated fuel valve in accordance with 5 whether the pilot is ignited or not.

while not so limited is particularly applicable to the latter and a pilot valve,

Other objects of the invention will be apparent from the accompanying specification, claims, and drawings, of which:

Figure l is a sectional view of a portion of a novel valve apparatus of the present invention. thewsection being taken along the line l-l of Figure 2;

Figure 2 is a perspective view with a portion broken away of the valve apparatus of the present invention;

Figure 3 is a sectional view of the valve apparatus shown in Figures 1 and 2, which section is taken along the line H of Figure 2;

Figure 4 is a detailed sectional view with a section taken along the line 4-4 of Figure 3;

Figure 5 is a detailed sectional view of another portion of my valve apparatus, the section being taken along the line 5-5 of Figure 3; and in which Figure 6 is a schematic view of a novel fuel burner control system employing the valve apparatus of the present invention.

Referring to the drawings, Figures 1 to 5 generally show the details of a novel valve mechanism which is particularly adapted for use in a gas burner control system. The valve in general comprises a diaphragm valve, the operation 'of which is controlled by a control valve. The valve mechanism further comprises a pilot burner valve which controls the supply of fuel to the pilot burner. when the pilot burner is ignited, the position of the control valve and consequently of the main valve is controlled in accordance with a bulb located in the space heated by the main burner. In the event of the. pilot burner being extinguished, both the main and the pilot burner valves are closed through a thermo-coule arrangement.

Referring first to Figure 3 of the drawings, it

will'be noted that there is shown a diaphragm valve having a housing, the lower section of which is designated by the reference numeral II.

This housing is provided with an inlet connection II and an outlet connection l3. Adjacent the outlet connection l3 there is provided a raised annular portion ll which serves as a valve seat to control the flow of fuel between the inlet and outlet. A valve disk ii of any suitable construcis provided with an aperture through its central portion and a sleeve 20 extends through this aperture, being secured to the diaphragm l5 by a nut 2|. The lower portion of sleeve 20 is provided with a pair of spaced

shoulders

22 and 23. Secured to the interior of the lower section of the valve housing is a bracket member 25 to which is pivotally secured a lever member 26. Secured to lever member 26 through suitable fastening means 21 is a valve disk l5. The outer end of the lever member 26 is slotted and two spaced arms. of the slotted portion extend between the

shoulders

22 and 23 of sleeve member 20. It will be readily seen that the lever member 25 serves as a means for transmitting movement of diaphragm II to the valve disk l5 so thatupon upward movement oi diaphragm It, the valve disk I5 is raised from its seat.

Due to the fact that sleeve 20 has a passage extending therethrough, a restricted communication between the two sides or the diaphragm I8 is provided. -Asmayfi ba a subsequentdescript'ioi'itif the" operation or the device, it is imperative that this restriced passage be open at all times. Accordingly, there is provided a spring member-2'9 which has an elongated stem portion 30 extending through the passage in sleeve 20 and terminating in an eyelet 3| which prevents the stem portion of spring 29 from being pulled out of sleeve 20. As will be more or less obvious, the upper movement of diaphragm II will cause the upper portion of the spring 29 to abut the upper portion of the valve casing causing stem 30 of spring 29 to move downwardly through the aperture in sleeve 20. The result is that each time that the diaphragm I8 is actuated,

"the stem portion 30 of spring 29 is reciprocated in the opening of sleeve 20 thus acting to clean the passage of any deposits that may collect therein.

In order to better understand the function of the apparatus to be subsequently described, it may be noted that the pressure motor comprising diaphragm I8 is of the type wherein one side of the diaphragm is constantly subjected to the full force or the motor fluid which may be the gas controlled by the valve. A bleed opening is provided through the diaphragm and the other side is subjected only to the pressure of the fluid which passes through the bleed opening. A bleed pipe is connected to the side of the diaphragm to which the gas bleeds and is provided with a control valve which when open permits the gas to bleed away from the chamber faster than it can bleed into the chamber by reason or the opening in the diaphragm. When the control valve is closed, the gas bleeding between the two sides of the diaphragm is allowed to accumulate in the chambento whichit bleeds with the result that the diaphragm is moved in the opposite direction. It is usual to arrange the pressure motor with respect to the valve actuated thereby so that the control valve in the bleed line is open when it is desired to open the valve and closed when it is desired to close the main valve.

Referring'now to Figure l, the control valve for the bleed gas leaving the'upper side of the chamber I8 is generally designated by the reference numeral 35. This valve is located in a boss 36 projecting interiorly from a wall ll 01' the upper. portion I6 01 the valve housing. A screw threaded gland 3'| is secured in this boss and serves as a guide for a valve stem 30 to which is secured a valve head 39, cooperating with a valve seat 40 Iormed by the juncture of a larger re- Since the position 42 of the boss 36. The valve stem 38 is provided with a collar 43 and interposed between collar 43 and the gland nut 31 is a spring 44. As shown more clearly in Figure 5, the valve chamber communicates with the upper side 01' the diaphragm I! through a passage 46. Also communicating with the valve chamber on the other side of the valve seat is a passage 41 which is threaded at its outer end to receive a pipe 48 leading to some bulb 53 is located in the space heated by the burner controlled by the valve. The burner may desirably be a burner 01 the space heater type wherein the burner is located in the room to be heated, as distinguished from a furnace which is located in a basement remote from the rooms which are actually being heated. The bulb 53 is filled with some volatile fluid which is partly in a vaporous state at or about the temperature which it is desired to maintain in the room being heated and which is connected through flexible tubing 54 with the interior of a chamber 55 surrounding the bellows 52. Bellows 52 has connected thereto a stem member 55 which has a conical pin 51 which is adapted to bear against a member 58 secured to lever 50 which is provided with a conical recess in each side thereof.

The spring 5| is interposed between a disk 60 provided with a conical point Bl seated in one of the conicalrecesses of member 58 and a collar member 62, the position of which is determined by a screw member 63. Screw member 53 is threadedly connected with collar 62 and has rigidly secured at the outer end thereof a handle member 54 which facilitates rotation of screw 63 and a consequent movement of disk 82 inwardly or outwardly changing the tension on spring 5|.

ot lever member 50 is determined by the opposing action oi the bellows 52 and the spring 5|, it will readily be temperature at which lever arm 50 from one position to another can be varying the tension of spring 5|. a means for regulating the temperature at which is actuated changed by the control valve is moved from one position to another position and consequently the temperature at which the burner is brought into opera tion. The handle 54 is provided with a pointer 85 which pointer cooperates. with a dial 66 which bears suitable indicia thereon to indicate the setting of the thermostatic apparatus previously described.

As indicated in Figure 2, the lever member 50 is provided with an arm 61 to which is secured an extension 12 oi'= magnetic material which member cooperates with a permanent magnet 13. The effect of this magnet is to tend to retain lever 50 in a position shown in Figure 1 so that it is necessary for there to exist an appreciable differential between the pressures exerted by spring 5| and by bellows 52 before lever 5|! is moved to a position permitting valve 35 to open.

After the temperature has dropped to the point where the member 50 is moved to a position wherein valve 35 is open and the temperature to cessed portion 4| with a smaller recessed portion seen that the r This serves as whiehbulbllissubjectedbeginstorisecausing thepreasureerertedthroughbellowslI-toex Astopmemberllissecuredtoasidewalllioftheeasing l6. Thisstopmemberservesto limit the outward movement of the lever II. The inwardmovementoftheleverislimitedbyreason of valve 8! engaging with valve seat II.

The numeral I. is used to generally indicate a valve which is adapted to control the flow of gas to a pilot burner. This valve is located in a boss It projecting from the wall 3|. A gland nutllisthreadedintothebosslt andactsas a guide for a valve stem It to which is secured a valve head II. The valve head 80 is adapted to cooperate with valve seat ll formed by the juncture of a portion .2 of comparatively large diameter with a recessed portion 83 of relatively small diameter. The valve stem It has secured thereto adjacent its outer end a collar 85. Interposed between collar 85 and the gland I1 is a spring 8' which serves to bias the valve head Ill away from the valve seat 8|. Referring toFlguresSand4,itwillbenotedthat thepassage formed by the recessed portion 83 communicates with a e 81 which in turn communicates with a similar passage 88 in the lower section II of the valve housing. The passage 88 connects with the space on the underside of the diaphragm. which space is in constant communication with the inlet II, Connecting with the e formed by portion I2 is a passage I which is provided with screw threads at its outer end to facilitate the connection thereto of a pipe OI which may lead to a pilot burner. interposed in the e 0. is a needle valve 82 which may be adjusted to regulate the flow of gas to the pflot burner. A lock nut 93 cooperates with needle valve to lock the same in any desired adjusted position. It will be seen that when the valve II is open, gas may flow from the inlet side of the valve housing through passages ll, ",1" and II to pipe II which, as previously indicated, preferably leads to a pilot burner of suitable construction.

As indicated in a previous portion of the specification, the valve mechanism of the present invention is provided with an arrangement wherein upon the pilot burner being extinguished, both the control valve It and the pilot burner valve II will. move to closed position; The mechanism i'or so moving these valves will now be described. Secured to the side wall ll of the valve casing' is a housing member 95 which is provided with a cover It apertured at 91. Extending through this aperture 51 is a rod at, which rod has secured at its end adjacent the valves 3! and II, a collar 99. An elongated striplike member "II is pivotally secured to the collar member I! and is so disposed relative to the valve structures II and II, previously described. that upon rod member ll being moved in the direction of the valves, the member llll is caused to bear upon the end of stem "of valve It and upon the u of valve ii. The cover it is recessed at Ill andlocatedinthisrecessisaspring I'll cooperate with a magnet generally indicated by the reference numeral III. This magnet is provided with a core III of very high permeability and the windings III of the magnet are of relatively large wire for a reason subsequently to be set forth. It will be readily seen that when the magnet llil is energized and the armature III is held in engagement therewith that member I" will be sufliciently retracted, that valve 15 will be moved to open position by the spring I6 and that valve 35 will move to the position permitted by lever 50.

A thermo-couple is employedto energize the magnet it]. This thermocouple is generally designated by the reference numeral Ill and comprises the usual elements Ill and ll! of different thermo-electric characteristics which are joined at H3 to form the hot junction oi the thermo-couple. The two elements ill and Il 2 may be of any desiredmaterials which have suitable thermo-electric characteristics to generate current sufficient for the energization of magnet III. As one exampleof the materials which may be employed, it has been found particularly successful to employ an outer element H I of stainless steel. The stainless steel may be oi. any form which is capable of resisting the heat of a pilot flame. In the example referred to, the inner element was made of Constantan" which is an alloy consisting of approximately fifty per cent nickel and fifty per cent copper. The outer member II I isv secured through a copper reducing sleeve Ill to a copper tube Ill. ,Secured to the inner member II) is an insulated conductor lit. Conductor H8 is securedthrough a connecting sleeve III to one end of the winding It! of magnet lll. A sleeve III of insulating material is disposed over the connecting sleeve HI and surrounding the sleeve I I1 is an outer coupling sleeve II! which serves to secure the copper tube lit to the housing and which also serves to electrically connect the copper tube II! with the other end of the winding ll! of magnet illl. The size of the copper tube III and the conductor H8 is comparatively large so as to oiler an extremely low resistance to the conduction of current therethrough. This is imperative inasmuch as the voltage generated by the thermo-couple is relatively small, and in order to obtain a sufllcient flow of current through the winding of magnet I", it is necessary that all of the conductive members have a comparatively low resistance.

Slidably mounted in an enlarged portion of the wall II of valve casing I6 is a pin l2. Thispin is provided with a button portion I16 which is slidably mounted in a recess I21 in the valve casing wall. Located in this recess I21 surrounding the pin I25 is a spring I28 which serves to bias the pin I" outwardly. A small pin l2! extends transversely through pin I I! to form a stop to limit away from the end of valve stem 38.

the outward movement of pin I25. It will be noted that the button I26 extends outwardly from the casing I6 so as to bereadily engaged manually from the exterior of the, casing. Upon push ing'button I26 inwardly, the inner end of the pin. I25 engages member I00. If this movement is continued, member I will be moved in the direction of wall H of the valve casing, being pivoted about the end of the valve stem 38 of valve 35. This movement will cause armature I04 to approach the core I08 of the magnet I01. This movement "will also cause member I00 to move away from collar 85 permitting spring 86 to movevalve 80 to open position. The result of push button I26 being moved entirely in, is, accordingly, that armature I04 is brought into engagement with the core of magnet I01 and that valve 15 is moved'to open position. At the same time, valve 35 is held closedeven more securely than-before due to the fact that mem-,

ber I00 is pivoted about the end of valve stem 38. Upon the push button I26 being actuated in the manner described in the previous paragraph,

if the magnet is energized so that armature I04 is 7 held in engagement therewith,-the release of push button I26 will permit member I00 to be moved What happens is that upon armature I04 being so held, the member I00 is free to pivot about its pivotal connection with collar 98 so that the biasing springs 44 and 86 are effective to move member I00 to a position wherein both valves 35 and 15may be in In Figure 6 of the drawings, there isshown, in

schematic form, the valve mechanism of the present invention incorporated in a novel fuel control system. Although the valve mechanism is shown in schematic form, the same reference,

characters have been employed in connection with this portion of, Figure 6 as were used in the description of the valve mechanism in connection with the previous figures. It is believed that from the previous description, the relation of the various elements of the valve mechanism in Figure 6 will be readily apparent so that substantially no further description of the same will be set forth in connection with this valve.

Referring to Figure 6, a gas burneris designated by the reference numeral I35. This gas 7 burner is supplied with gas through a pipe I36 connected to the outlet I3 of the main gas valve previously described. Connected to the inlet I2 .of'the gas valve is a pipe I31 which leads to a gas main.

A pilot burner is designated by the reference numeral I38. This burner is connected through pipe BI to the passage 98 which is controlled by valve 15 as described in connection with Figure 4. For the purposes of illustration, a pipe I40 is shown as connecting the underside of the valve casing with valve 15 in lieu of passages 88, 81 and 83. V

In order to simplify the showing of the valve mechanism in this figure, a pipe I H is shown as connecting the upper portion of the valve casing The pipe 48 referred to in connection with Figure with valves", instead of

passages

42 and 46.

5 is shown as extending to a point adjacent the pilot burner I38 so that the gas escaping therethrough Operation The various elements are shown in Figure 6 the position which they assume when the burner is out of operation and when the pilot burner I38 is extinguished." If it is desired to start the operation of the system, it is first necessary to light the pilot burner I38. In order to do this, button I26 is pushed inwardly in the manner previously described. This pushing inwardly of button I26 causes member I00 to be pivoted about the end" of the valve stem 38 of valve 35 causing the armature I04 to move into engagement with the magnet I01 and at the same time'to permit biasing spring 86 to move the valve 15 to open position.

- The result is that gas is admitted through pipe I311 underneath the diaphragm, through pipe I40, valve 15 and pipe 9| to the pilot burner I38, the gas escaping from this pilot burner I38 being ignited by any suitable means.

As the button I26 is held inwardly, holding and will permit the biasing spring 44 of valve 35 to move valve 35 to a position permitted by lever 50. Usually when the burner is being started up in this manner, it is because the'temperature of the space heated by the burner has fallen to a point where there is a demand for heat. Under these conditions, the position of lever 50 will be such that upon member I00 being held by the magnet I01, spring 44 will be efiective to move the valve 35 to open position. When this takes place, the gas above the diaphragm I8 is permitted to bleedoflf through pipe I through valve 35 and pipe 48. Since gas can bleed off in this manner faster than it can bleed through the diaphragm, the effect is to relieve the pressure above the diaphragm. As previously explained, the underside of the diaphragm is constantly subjected to the pressure of the supply gas so that as soon as the pressure above the diaphragm is released in this manner, diaphragm I8 moves upwardly causing valve I5 to move to open position and permitting gas to flow to burner I35.

The operation of the burner will normally condiaphragm, however, and in a very short period of time the pressure will be built up in the chamber above the diaphragm sumciently to cause downward movement of diaphragm I8 and the closing of valve I5.

If during the operation of the valve as previously described, the pilot burner flame is for any reason extinguished, the hot junction of the thermo-couple IIO will no longer be heated with a result that magnet I01 is deenergized. -The deenergizatlon of this magnet will release the armature I04 permitting spring I02 to move member I00 to the position shown in Figure 1 ,will, be consumed in the pilot burner wherein this member is effective to hold both valves 35 and I closed. The closing of valve I! will interrupt the supply 0! fuel to the burner III and the closing oi valve will interrupt the supply of fuel to the pilot burner Ill. In this manner, the danger of an explosion arising from gas being admitted to an unignited burner is resetting mechanism comprising the pin I25, it

was assumed that the pilot burner was properly ignited and that the thermo-couple Ill became heated sufliciently to energize magnet Ill and hold armature I in engagement therewith. If for some reason the pilot burner is not properly ignited, the release of push button I26 will cause the pilot burner valve 15 to be closed and the parts to again assume the position shown in Figure 1. It will be noted that the inward movement of pin I by actuation of push button I26 does not cause the opening of control valve 35 so that a reciprocation of this member does not admit gas to the main burner unless the pilot burner is ignited. By the arrangement described, it is impossible for someone toaccidently admit gas to the main burner, which gas is unignited, by pushing button I26. The only time that actuationof push button I26 will open the valve I! and consequently cause admission of gas to the main burner is when the pilot burner is ignited while push button I26 is held inwardly during such actuation. Moreover, not only is the control valve not open during reciprocation of the resetting member, but this valve is held even more firmly against the .seat during such operation than normally.

' While I have described my invention as applied to a fuel burner control system, certain features thereof are deemed to be applicable to the control of any two valves which are to be operated successively by some actuating means. Moreover, while I have described the operation of the main valve as being controlled by a control valve, it is to be understood that in lieu of the control valve, some other control device might be substituted without departing from the scope of the invention. It is to be understood that the specific embodiment of my invention shown and described is for purposes of illustration only and that my invention is to be limited only by the scope of the appended claims.

I claim as my invention: 7

1. In a fluid fuel burner control system, a main burner, a pilot burner, a main valve controlling the flow of fuel to said main burner, a pressure motor for operating said main valve, means for supplying a pressure fluid, to said motor to operate the same, a control valve for controlling the pressure in said motor, said pressure motor being operative when said control valve assumes a first position to hold said main valve in closed position and when said control valve assumes a second position to move said main valve to open position, controlling means including a device responsive to a normally controlling condition for varying the position of said control valve, and means operative to move said control valve to said first position in the absence of a flame at said pilot, said last named means comprising a member adapted to cooperate with said control valve and biased to a position wherein the control valve is held in said first position, an electromagnet adapted to hold said member in a different position wherein said control valve is under the control of said controlling means, and means for controlling the energization of said electromagnet in accordance with the absence or presence of a flame at said pilot.

2. In a fluid fuel burner control system, a main burner, a pilot burner, a main valve controlling the flow of fuel to said main burner, a pressure motor for operating-said main valve, means for supplying a pressure fluid to said motor to operate the same, a control valve for controlling the pressure in said motor, said pressure motor,being operative when said control valve assumes a first position to hold said main valve in closed position and when said control valve assumes a second position to move said main valve to closed position, controlling means including a device responsive to a normally controlling condition for varying the position of said control valve, and

means operative to move said control valve to said flrst position in the absence of a flame at said pilot, said last named means comprising a member adapted to cooperate with said control valve and biased to a position wherein the control valve is held in said first position, a magnet adapted to hold said member in a different position wherein said control valve is under the control of said controlling means, and means for controlling the energization of said magnet comprising a thermo-couple having its hot junction located in the path of the pilot burner flame.

3. In combination, a pair of valves each movable from a first to a second controlling position, one of said valves being adapted when moved to its second controlling position to make possible the establishment of a condition which should exist prior to the movement of said second valve to its second controlling position, means'biasing each of said valves to its second controlling position, yieldable means for holding said valves in said first controlling position against the action of said biasing means, holding means including a device responsive to said condition for holding said yieldable means when said condition exists, in a retracted position wherein the position of the valves is not affected thereby,

' and reciprocable means operable upon actuation in one direction to move said yieldable means to a position wherein it may be held by said holding means upon the existence of said condition and wherein it is ineflective to hold said first valve closed but effective to hold said second valve closed, said yieldable means being operative upon actuation of said reciprocable means in the opposite direction and upon being held by said holding means to assume said retracted position wherein said second valve is also free to move from its first controlling position.

4. In-combination, a pair of valves each movable from a first to a second controlling position, one oi said valves being adapted "when moved to its second controlling position to make possible the' establishment of a condition which should exlstprior to the movement of said second valve to its second controlling position, means biasing s at a point intermediate said valves and in a position such that said member does not restrict the movement of said valves, and reciprocable means for engaging said member adjacent the end thereof opposite said second valve and tilting said member about said second valve to simultaneously move said first valve to its second con-' trolling position and said member into a position wherein said holding means may engage the same if said condition exists, said biasing means being operative in the event of said holding means being eifective and upon release oi said reciprocabie means to move said second valve to its second controlling position. a

5. In combination, a plurality oi valves each biased to open position, one of which when open makes possible the establishment of a condition which should exist before the second valve is opened, yieldable means including a pivoted member eflective to hold said valves inclosed condition against the action of said biasing means, holding means including a device responsive to said condition for holding said yieldable means in aposition wherein said valves may move to open position, and a reciprocable member engaging said pivoted member and operable upon movement in one direction, to push said yieldable means to a position wherein said first valve is open and said second valve closed and wherein said holding means is adapted to hold said yieldable means, said pivoted member being operative upon said yieldable means being so held and upon said reciprocable member being moved in the opposite direction to assume a position wherein said second valve may move to open position.

6. In a control system, a pair 01' valves each controlling a different condition, a biasing means associated with each of said valves for urging the valve to a firstposition wherein the respective condition controlled by it may be established, common biasing means acting on said valves in opposition to and, with a greater force than said individual biasing means to move said valves to a second position, means for tilting said common biasing means to a position wherein said common biasing means is inefiective to oppose the individual biasing means of one of said valves so as to cause said valve to be moved to its first position, and means including a device responsive to the condition established by the movement of said one valve to its first position to hold said operative upon release oi said actuating means and upon the holding means" being eiiective as the result oi the presence of the first condition to move said second biasing means to said secposition, a lever member engaging each of said valves, a second biasing means efl'ective on said lever member at a point intermediate said valves and acting in opposition to and with suiiicient force relative to the first mentioned biasing,

means to, hold said valves closed, a reciprocable actuator adjacent one of said valves and adapted upon movement in one direction to pivotally move said lever member away from thevalve adjacent said actuator and about said other valve, and

common biasing means ina position wherein upon release of said tilting means, said common biasing means is inefiective to oppose the individual biasing means of the other valve.

'7. In combination, means for establishing a predetermined condition, means including a valve for establishing a second condition upon the first condition being established and upon said valve being moved from a first to a second controlling position, a first biasing means acting to bias said valve to said second controlling position, a second biasing means acting when in a first position in opposition to and with greater force than said first biasing means to hold said valve in said first controlling position, holding means including a device responsive to said first condition for holding said second biasing means upon the establishment of said first condition in a second position wherein the valve it not affected thereby,

and actuating means for moving said second-bimeans to pivotally hold said member adjacent the point at which said second biasing means acts when said member is so moved, the first mentioned biasing means of said other valve being operative upon movement of the actuator in the opposite direction to move said lever member when so pivotally held in a position wherein it does not prevent opening movement of either valve. 1

9. In combination, a pair of valves, biasing means for each valve urging the same to open position, a lever member engaging each 01'- said valves, a second biasing means effective on said lever member at a point intermediate said valves and acting in opposition to and with suflicient force relative to the first mentioned biasing means to hold said valves closed, a reciprocable actuator adjacent one of said valves and adapted upon movement in one direction to pivotally move said lever member away from the valve adjacent said actuator and about said other valve, and holding means comprising a magnet and armature one of which is pivotally connected to said lever member adjacent the point at whichsaid H second biasing means acts and the other oi valve being operative upon movement of the ac-' tuator in the opposite direction to move said lever member when so pivotally held in a position wherein it does not prevent opening movement of either valve.

.10. In a fluid fuel burner control system, a main burner, a pilot burner, means for regulating the flow of fuel to said main burner including a control device movable between a first position in which the fiow of fuel is prevented and a second position wherein said flow is permitted, a pilot valve for controlling the fiow of fuel to the pilot burner, controlling means including a device responsive to a normally controlling condition for moving said control device between its two positions in accordance with the value 01' said condition, means responsive to the presence or absence of a flame adjacent said pilot burner and operative upon the pilot flame being extinguished to move said control device toits first position i and said pilot valve to its closed position, and means including a reciprocable element for resetting said control device and said pilot valve when so moved, said resetting means being oper able upon movement of said element in one direction to cause saidpilot valve to open while holdsaoes upon movement of said element in the reverse direction to permit said control device if said pilot is ignited to assume a position wherein it is under the control oi said controlling means.

11. In a fluid tuel burner control system, a main burner, a pilot burner, means for regulating the how of fuel to said main burner including a-control device movable between a first position in which the flow oi fuel is prevented and a second position wherein said flow is permitted, controlling means including a device responsive to a normally controlling condition tor moving said control device between its two positions in accordance with the value of said condition, meansresponsive to the presence or absence of a flame adjacent said pilot burner and operative upon the pilot flame being extinguished to move said control device to'said first position independently of I said controlling means, said means'comprising a member biasing said control device to said first position, a' magnet for holding said member in a position wherein said control device is under the control of said controlling means, and means for energizing said magnet in accordance with the absence or presence'of a flame at said pilot.

12. In a fluid fuel burner control system, a main burner, a pilot burner, means for regulating the flow of fuel to said main burner including a I control device movable between a first position in which the flow of fuel is prevented and a second position wherein said flow is permitted, controlling means including a device responsive to a normally controlling condition for moving said control device between its two positions in accordance with the value oi said condition, means responsive to the presence or absence of a flame adjacent said pilot burner and operative upon the pilot flame being extinguished to move said control device to said flrst position independently oi said controlling means, said means comprising a member biasing said control device to said first position, a magnet for holding said member in a position wherein said'control device is under the control or said controlling means, and means for energizing said magnet comprising a thermoi couple having its hot iunction located in the path of the pilot burner flame.

13. In combinatio a pair of valves, one of which is adapted to control a condition which should exist before the other valve is opened, and actuating means for said valves includinga reciprocable member and a device responsive to said condition, said actuating means being eilective upon said member being moved in one direction to cause said first valve to be moved to a position making possible the establishment of said condition while applying part of the force applied to said reciprocable member to said other valve to hold the same cloud, and upon said member being moved in the opposite direction to cause said second valve to be opened in the event of said conditon having been established.

14. In combination, a pair or valves, one of which is adapted to control a condition which should exist before the other valve is moved from a first to a second controlling position, and actu atng means for said valves including a reciprocable member and a device responsive to said condition, said actuating means being efl'ective upon said member being moved in One direction to cause said first valve to be moved to a position making possible a change in said condition while applying part of the force applied to said reciprocable member to said other valve to hold the same in said first position, and upon said member being moved in the opposite direction to cause said second valve to be moved to said second position in the event of said condition having been established.

15. In combination, a burner, a device adapted upon being moved to a first position to establish a, condition which is desirable only when said burner is ignited, a lever adapted to bear against said device, yieldable means urging said lever into engagement with said device so as to hold said device in a second position, holding means comprising an armature unit and an electromagnet unit, one 0! said units being fixedly mountedand the other pivotally connected to said lever at substantially the same pointv at which said yieldable means acts on said lever, which point is spaced from that at which the lever engages said device, a thermo-couple having its hot Junction located in said burner'flame and connected to said electromagnet unit, said thermocouple being eii'ective when said burner is ignited to energize said electromagnet unit suiliciently to hold said two units together against the action 01 said yieldable biasing means, and an actuating member adapted to engage said lever and eflective upon being moved in one direction to rock said lever about said deviceand move said two units together whereby said device is free to move to said first position only alter return movement of said actuating means and upon said electromagnet unit being energized.

18. In combination, a burner, a valve adapted upon being moved to a'first position to establish a condition which is desirable only when said burner is ignited, a lever adapted to bear against said valve, yieldable means urging said lever into engagement with said valve so as to hold said valve in a second position, holding mean comprising an armature unit and an electromagnet unit, one of said units being fixedly mounted and the other pivotally connected to said lever at substantially the same point at which said yieldable means acts on said lever, which point is spaced from that at which the lever engages said valve, a thermocouple'having its hot Junction located in said burner flame and connected to' said electromagnet-unit, said thermocouple being efiective .when said burner is ignited to energize said electromagnet unit suiilciently to hold said two units together against the action otsaid yieldable biasing means, and an actuating member adapted to engage said lever and effective upon being moved in one direction to rock said lever about said valve and move said two units together whereby said valve is free to move to said first position only after return movement of said actuating means and upon said electromagnet unit being energized.

17. In combination, a burner, a valve adapted upon being moved to open position to establish a condition which is desirable only when said burner is ignited, a lever adapted to bear against said valve, yieldable means urging said lever into engagement with said valve so as to hold said valve in closed position, holding means comprising an armature unit and an electromagnet unit, one of said units being flxedly mounted and the other pivotally connected to said lever at substantially the same point at which said yieldable means acts on said lever, which point is spaced from that at which the lever engages said valve,'a thermocouple having its hot lunction located in said burner flame and connected we said electromagnet unit sufficiently to hold said two units together against the action of said yieldable biasing means, and an actuating member-adapted to engage said lever and 'eflective upon being moved in one direction to rock said lever about said valve andm'ove said two units together whereby said valve is free to open only after return movement of said actuating means and upon said electromagnet unitbeing ener- 18. In combination, a "control device movable between a safe position and an active position, an electromagnet, an armature movable into and out oi engagement with said electromagnet, said electromagnet being capable of holding said arinature but incapable of moving said armature into engagement therewith, means including a mechanical connection between said armature and said control device for directly moving said control device to its safe position upon release of the armature by the electromagnet, andremovement of said actuating means and upon said electromagnet unit being energized.

22. In combination, a main fluid fuel burner, a pilot burner therefor, valve means controlling the flow of fuel to said main burner, a valve housing for said valve means having a main passage leading to said burner and an auxiliary passage leading to said pilot burner, an electromagnet, an armature movable into engagement with said electromagnet, means responsive to the presence of a pilot flame for energizing said electromagnet sufficiently to hold said armature in setting means for movingsaid armature into engagement with said electromagnet without movement of said control device from said safe position, said means further being effective upon said armature being held by said electromagnet and release of said resetting means to movesaid control element to said active position.

19. In combination, a control device movable between a safe position and an active position, an electromagnet, an armature movable into and out of engagement with said electromagnet, means biasing said armature out of engagement with said electromagnet, said electromagnet being capable of holding said armature but incapable of moving said armature into engage ment therewith against the action of said biasing means, a mechanical connection between said armature and said control device by which said biasing means moves said control device to its safe position upon release of the armature by the electromagnet, and resetting means for moving said armature into engagement with said electromagnet against said biasing means without movement of said control device from said safe position, said mechanical connection being eifective upon said armature being held by said electromagnet and release ,of said resetting means to move said control element to said active position.

20. In combination, a valve, an electromagnet, an armature movable into and out of engagement with said electromagnet, said electromagnet being capable of holding said armature but incapable of moving said armature into engagement therewith, a mechanical connection between said armature and said valve for directly moving said valve to closed position as said armature moves away from said electromagnet upon release by said electromagnet, and resetting means for moving. said armature into engagement withsaid electromagnet'without opening of saidvalve, said mechanical connection being efl'ective upon said armature being. held by said electromagnet and said resetting means being moved to its original position to open said valve.

i 21. In combination, a valve, means for moving said valve to a first position, a member adapted to move said valve to a second position, holding means for said member, said holding means comprising an armature unit and an electromagnet unit, one of said units being fixedly mounted and the other being pivotally connected to said member, said electromagnet unit being capable engagement therewith but insufficiently to move it .into engagement therewith, means associated with said armature for moving said valve means to a fuel flow preventing position when said armature is released from said electromagnet, resetting means for moving said armature into reengagement with said electromagnet, and means operable upon actuation of said resetting means to establish communication between the inlet side of said valve means and said'auxiliary passage to said pilot burner whilepreventing the flow of fuel through said main passage to said main burner.

23. In combination a main fluid fuel burner, a pilotburner therefor, valve means controlling the now of fuel to said mainburner, a valve-housing for said valve means having a main passage leadingto said burner andan auxiliary passage leading to said pilot burner, an electromagnet, an armature movable into. engagement with said electromagnet, a thermocouple having its hot junction in the pilot flame for energizing said electromagnet sufilcientiy to hold said armature in engagement therewith but insufliciently to move it into engagement therewith, means associated with said armature for mechanically moving said valve means to a fuel flow preventing position when said armature is released from said electromagnet, resetting means for moving said armature into reengagement with said electromagnet, and means operable upon actuation of said resetting means to establish communication between the inlet side of said valve means and said auxiliary passage to said pilot burner while preventing the flow or fuel through said main passage to said main burner.

24. In combination, a valve, an electromagnet, an armature movable into and out of engagement with said electromagnet, said electromagnet being capable of holding but incapable of moving said armature-into engagement therewith, a single biasing means acting to move said armature away from said electromagnet and said a out of engagement with said electromagnet, said electromagnet being capable of holding but in.- capable of moving said armature into engagement therewith, a single biasing means biasing said armature away from said electromagnet and said control device to a position in whichthe valve moves to a predetermined position, and a reset member operable when moved from a normal position to a reset position to move said armature into engagement with said electromagnet, and means operated by said resetting member for maintaining said valve in said predetermined position while said reset member is' in said reset position, said means being immediately effective upon movement of said reset member back to its normal position to'permit said control device to assume a position in which said valve may move away from said predetermined position. 7

26. In combination a control device having a -safe position and an active position, an electromagnet unit, a cooperating armature unit, one of said units being fixed and the other unit being movable into and out of engagement with said fixed unit and mechanical connecting means between said control device and movable unit for transmitting the movement of said movable unit away from said fixed unit to said control device to move said control device to its safe position, said connecting means being operable to permit application of manual force for moving said movable unit back into engagement with said fixed unit without returning said control device to its active position while thereafter causing such return of said control device upon removal of said manual force and retention of said movable unit by' said fixed unit.

27. In combination, a control device having a safe position and an active position, an electromagnet unit, an armature unit, one of said units being fixed and the other of said units being movable into and out of engagement with said fixed unit, a mechanical connection between said movable unit and said control device for moving said control device to its safe position upon movement of said movable unit away from said fixed unit, means for applying a force to said connection in such manner that the movable unit is moved into engagement with said fixed unit and the reaction of such force positively holds said control device in its safe position, and means to return said control device to its active position upon removalof said force if said movable unit is retained by said fixed unit.

FREDERICK D.- JOESTING.