US2612946A

US2612946A - Flame sensitive fuel cutoff device

Info

Publication number: US2612946A
Authority: US
Inventors: Clifton A Cobb
Original assignee: Missouri Automatic Control Corp
Current assignee: Missouri Automatic Control Corp
Priority date: 1947-10-20
Filing date: 1947-10-20
Publication date: 1952-10-07
Anticipated expiration: 1969-10-07

Description

Oct. 7, 1952 C, A, CQBB 2,612,946

FLAME SENSITIVE FUEL CUTOFF` DEVICE Filed Oct. 20, 1947 3 Sheets-Sheet l '7/ 65 ff a7 483 29 5g? V 59 77 LT' a5 /O-rme 82 g 9 9 /09 76 d( 6g 60 l* M l' l 56@ 63 5 7 4g 62 46 56 54 j 46 35 /0 :1.F 44 3g 4f 40 zf? 42 55 4.3

' /m/f/vroe.- 5354 M 62 /Fro/v ,9. C055,

50 52 w ZM@ Oct. 7, 1952 C, A, COBB 2,612,946

FLAME SENSITIVE FUEL CUTOFF DEVICE Filed Oct. 20, 1947 Sheets-Sheet 2 @I C C I E t C C:

. MII y? 57@ 96 56 I/MBIQX .lllnw 64 96 llllllisunm y@ Hdllf 96 f6 lll 97 NN" i l 95 /56436 l 62/ 35 6348 33 25 l Zi? 62 46 u- 59 33 3 455548 40 44 6] 39 l-I" .f 4 ,47 4/ Z 54 4/ l- 54 .a

49 & 49 43 53 53 l /A/a/E'Mroe:

45 52 56g 54 funn/19.6058,

52 50 50 BVZM NGE/V72 Patented Oct. 7, 1952 FLAME SENSITIVE FUEL CUTOFF DEVICE r Clifton A.`('}obb,` University City, Mo., assignor` to I Missouri Automatic Control Corporation, St. Louis, Mo., a corporation of Missouri Application October 20, 1947, Serial No. 780,920

This invention relates to safetyfuel cut-off devices of the type in which a fuel control member being normally biased to a cut-off position is moved. manually to a fuel-on position,oand in which mechanism actuatedby llame sensitive means retains the control member in a fuel-on position while there is flame at the burner and automatically releases it upon loss of flame; It particularly relates to devices of this kind in which the fuel supply to bothY pilot `andmain burner is cut ofi upon loss of flame at the pilot burner and in which a safety feature :is included to prevent the flow of any fuel to theA main burner as the control is manually moved to a set position in order to relight thepilotv i It is an object of the invention to providel generally new and improved flame sensitivev fuel cut-off device which is quick acting and reliable in operation and which is not affected by' high temperatures ambient to the burner flame.1

It is a further object to provide a novel flame sensitive fuel cut-off device of themanual reset type in which the volume change due `to vaporization and condensation of a high boiling point liquid, sensitive to the burnerilame. is utilized to actuate mechanism for holding `the devicel in a fuel-on position when there is flamelat the burner, and for releasing it to returntoacutoff position upon loss of flame. o y Y o It is a further object to provide in adevice of this character apilot burner and a temperature sensitive bulb in which a continuous burner port supports an uninterrupted flame for heating the bulb and igniting the main burner and in which the bulb is formed and supported with` respect to the flame port so as to beheated` in its entirety. p o o o o It is a further object to provide anautomatic trip and manual4 reset type fuel cut-off device for controlling the fuel supply to both pilotI and main burners, whichlincludes a compoundvalve structure and actuating mechanism therefonby which fuel may be admitted to the pilot` burner exclusively, by manual operation, in the absence of flame at the burner. i

It is a further object to provide a safetyfuel cut-off device of this character having a compound valve and actuating mechanism therefor whereby the valve may be moved `manually to a set position `in which fuel is admitted to the pilot burner in the absence of flame and in which 8 Claims. i (Cl. 158--137) fuel is admitted tothe main burner' only after t ignition of the pilotburner and the return of the manual setting mechanism.

Other objects and advantages will appear in `cut-ofi valve generally indicated at 24;

2 the following description when studied in connection with theaccompanying drawings.

' `Referring to the drawings,

Fig. 1` is a cross sectional elevation of a fuel cut-off device constructed in accordance with Ythe present invention. `The remote temperature sensitive bulb is not, however, included' in this view but is vshown in enlarged detail in Fig. 6.

Fig. 2 is a partial View of the device shown in Fig.` l showing the manual reset plunger slightly depressed and the main burner lock out latch in position to prevent opening of the main burner port as the plunger is further depressed to a set position. l f

Fig.l 3 is a partial View of the device shown in Fig. l, showing the manual reset plunger in a fully depressed position. In this position the pilot burner port is open, the main return spring is compressed, and the lock out latch member is imposition to prevent opening of the main burner port by the counter spring. i i i Fig. 4 is a partial View showing the automatically actuated detent in set position wherein the upward return of the valve stem and thereforev the closing of the valves by the main spring is prevented. The manual resetplunger is shown returned to its uppermost position rand the lockout latch is moved toa position in which` the sleeve memberis released permitting the opening of the main burner port by counter spring pressure.`

1Fig."5 is a sectional view in part of the lower valve body, taken on line 5-5 of Fig. l, showing the outlet of the annular pilot port;

Fig. 6 is a cross sectional view of the temperature sensitive bulb shown attached to the upper portion of the pilot burner; t

Fig.4 7 is a top view of the pilot burner showing the burner port;

Fig. 8 is a partial view in section of the uppe endof the pilot burner showing the burner port:

Fig. 9` is a` front view of the upper part ofthe pilot burner showing the burner port;

Fig. l0 is a diagrammatic view of a fuel sup-- ply systeinfor main and pilot gas burners embodying a safety fuel cut-off` device constructed in accordance with the present invention.

In the diagrammatic view,vFig. l0, a pilot burner ist generally indicated at 20 having a temperature sensitive bulb mounted thereon generally indicated at 2|. A main burner (shown infpart)l is indicated at 22. Fuel is supplied to the main and pilot burners through a fuel line 23 which*v is connected to the inlet cfa safety fuel Leading from valve 24 is a fuel conduit 25 for suD- plying fuel to the pilot burner 20, and a fuel conduit 26 for supplying fuel to the main burner 22. Interposed in the conduit 26 is a valve 21 of any suitable type, which automatically controls the supply of fuel to the main burner for intermittent operation in accordance with requirementsi Mounted. on theA cut-off valve 24 is' a valve actuating mechanism generally indicated at 28, and there is a capillary tube 29 leading from the temperature sensitive bulb 2| to the` mechanism. .v v

Referring to Fig. l, the valve 24' includes a body member 30 having an: inletf3| to which the fuel supply conduit 23 is connected). an'outlet 3.21:. to which the main burner fuel supply conduit 26 is connected, and a side outlet. 33 (see detail Fig. 5) to which the pilot fuel supply conduit 25 is connected. The valve body is further. pro.- vided with a separating wall 34 having a hori- Zontal. portion 35 ini whichJ is formed: a central. main 'burner port: 36l anda concentric annular pilot port 31 having its. outlet at 90 to the inlet 31| as indicated-v a-t 33.. Surrounding the

ports

36 and 31 and on the lower surface of wall 35- are formedconcentric

circular valve seats

38 and 39 on. which seat an inner main burnery valve element 40v and an' outer pilot burner element 4| respectively.

The outer valve element 4| hasA a. generally' cup shaped. upper portion 42 and a central downwardly extending hollow stem portion 43, The top surface or rim. of thev cup portion is faced with a suitable pliable material, such'. as leather, as indicated at 44. The inner valve element 40- i-s disc shaped and has a central per'- foifation-` 45. The disc is provided with an upper facing of pliable material as indicated at 4S. There is also an upper bearing plate 41 which together with th'ev pliable facing is attached to the valve disc by rivets 48.

The valve body 3|!A is further provided with a lower threaded bore 49 whichreceives a thread` ed closure plug 5|), and an. upper concentric smooth bore 5| which receives and guides the valve stemr assembly. The closure plug 50 has acentral bore 52, which receives in sliding flt relationship the lower hollow stem portion of outer valve element 4|, and an annular recess 53 which receives one end of a main valve return springV 54. The other end of spring 54 bears against the lower side of the valve element 4| urging it toward a closed position. .Inner valve element 40 is urged toward a closed position by a spring 55 in the hollow stem portion 43 of the valve' 4|.`

There is a valve stem 56, the lower end of which is reduced as indicated at 56a. and which extends into the hollow stem portion 43 of valve 4| and 'bears against the lower closed end thereof. At its upper end the valve stem 56 is pro vided with a flange or head 51 and a downwardly extending longitudinal bore 58 which receives the lower reduced end of a manual reset plunger 59. The valve stem and its head 51 are joined by a tapered shoulder 51a. Surrounding valve stem 56 and having a sliding llt in the bore 5| is an upper sleeve'member 60. There is also a lower sleeve member 6| having asliding fit on the lower reduced portion 51 of the valve stem 56 and extending thru the perforation in the inner valve member 40 and downward into the hollow stem portion 43 of valve 4| and bearing against the bottom thereof.

The upper end of the lower sleeve 6| `has a 4 flange 62 which provides a surface for abutting the lower end of the larger upper sleeve. The under side of flange 62 also bears against the bearing plate 41 under certain conditions. The lower end of the larger upper sleeve 60 also has a flange 63. A counter spring 64 surrounding the upper sleeve 6|) and bearing at its upper end against V`the valve body and at its lower end against the-sleevefflangev 63 overcomes the rela tively light spring 55 under certain conditions and moves the inner valve member 40 to an open. position.. A

A frame member 65 is mounted on top of .valizevbodySJ andzi'sattached thereto by Screws 66?... There 'istfalso a housing 61, for enclosing the" valve actuating mechanism, which is attached to the upper part of the valve body by screws 68. vA pliable sealing gasket 69 is provided: `between the housing and the valve body to insure a fluid tight seal. The housing 61 has a perforation. ,atF the: top thru which projects a cup' shaped. sealing vcap 10 movable with the manual reset plunger 59. The cap 18 is provided-.with-a flange1| and there is a pliable gaslqetf-12. mounted on the flange to insure a fluidv tight seal. when` the plunger is in its normal 1ippermos-ty position.. .The upper end of plunger 59 is.proyided with a. head 13; and a spring 14 which bears'atonef end against the frame member 65 and at its. other end against the plunger head 13,"normally holds the plunger and the sealing cap in their uppermost,v position, as indicated i-rrEl-g. 1.

Pivoted ori-the: fra-me 65 at 15 is a lock out latch member .16.v having an upper angularly formed follower portion 11 and a lower angularly formed latch portion 18. Latch member 16 is biasedin. a clockwise direction by a spring 19 andthe upper follower end11 continuously bears against the reset. plunger 59.y The reset plunger 59 hasareduced lower portion 80 and a tapered shoulder` 8| isfo-rmed at the point of reduction. tapered shoulderprovides `a cam surface which acts tol rotatethe lock out latch member 16 counterclockwise against spring 'F9 as theplung'eris depressed. It will be noted that the lowerend of the plunger 59 does not reach the bottom of the bore 58 in the valve stem when the plunger is in its uppermost position, as shown inFigI, l, and that the plunger may be depressed somewhat initially before any downward movement is"y impartedtc thel valve stem or valve elements'. lThis initial downward movement of the plunger is suflicient to place the follower end 11 of. latch 16 on the `large diameter portion of the plunger, whereby the latch is rotated counterclockwise, moving the latching end 18 into a groove 82k formed in the upper sleeve member 6|] near its upper end.

Mounted on the 'side of the frame member 65 and attached thereto by screws 83 is an expansible element generally indicated at 84. The element consists 0f' an inner flexible cup mem- 1 ber 85 and an outer rigid cup member 86. The

outer'cup member isprovided with a flange 81 throughawhich the screws 83 pass for attachto the lower `end of the temperature sensitive bulb 2|, see Fig.`6. Bulb 2| has anuppereloll gated and curved chamber 9| and a concentric longitudinal bore 92, of smallerdiameterjthan the chamber, extending from its lowerL end;tcrthe` chamber. At the junction of the breand lthe chamber, the shoulder is beveled, "as indicatedl'at 93. bulb by inserting into bore 92 to the" poi'nt'of` its junction with the chamber and is'fa'ttached therein by Welding. lt is important thatthe tube extend precisely to the upper end of thebor'e` 92. The internaldiameter of the Vcapillary. tube is very small and its relationship toltlie diameter of the bulb chamber 0| is in thetorder oflfto 25. The bore 92 isof such diameter. as toreceive the capillary in push t relationshipw' y The bulb` 2| is attached near its .lowerl end Way between the circular openings, eirtendsupe` wardly to the end of the burner head andthen horizontally approximately' half way across lits closed upper end. The port` is arranged symmetrically with respect tothe vertical center line of the burner head and the bulb is mounted so that its vertical center line coincideslwiththe center line ofthe burner headso that'elongated flames supported by 'the circulaimopenings ,90

may be projected, without undue, obstruction by the bulb, for ignition oi" the` main burner. The bulb is also mounted so that aportion `of the curved chamber 5|` cverlaysjthejhorizontal portion of port slot 08 wherebylthe bulb'is pinged by name along its entire length.`

n wm be seen that the bulb 2l, the Icapniarif `tube 29 and the expansible element 84'fo`rm a sealed system. In the "manufaoturlehof the device, air is evacuated from this system; and with the bottom Wall of theinner liie'rible cup 85- pressed against the bottom wallfof-ithe outer cup 86, so that there is substantially" nospa'ce therebetween, the bulb and `capillary@are then filled with mercury. The expansible;` element 34 is so proportioned thatits volumeywhen eXn panded to its safe working limit,is at leastequal` to the volume of chamber 0|, vsolthaif,itl can receive substantially all 'of the `mercuryfrom the bulb. It is also desirable to proportionrthe` element so that its fully expanded volume:does not appreciably exceed the; volumeofxcharnber Bl, in order that the full working expansion of the particular type expansible element usedfmay be obtained. 11 i Reference is made to my copending application titled Temperature Responsive Control Serialy No. 773,646, filed September 12', 1947- n which l have shown and described a flainesensitive device utilizing the volume change due to vapori: zation of a small portion of a high boiling point` liquid contained in a flame heated bulb, .to `displace the remainder of `the liquid therein for, the expansion of a connected expansible element. The ame responsive actuator `embodied in the present invention employs this` principle.l l

The frame 65 `has a perforation concentric Wahine expansime nement in which is rats a guide bushing lou. lsndatiynaad inthe guide bushing is a spring extended telescopn-g detent The capillary tube 23 i`s` connected tothe assembly, generally indicated at |0l.` The detent assembly consists of a sleeve member |02, an inner slidable plunger member |03, an adjustable abutment element |04, a spring |05, and a retaining plug `|06. The sleeve member is" provided with la"reduced bore at one end and the plunger,` elementisreduced in diameterat one end to provide shoulders". Whichlimit the extension` of; the plunger.` Theplunger |03 is` further providedfwith a longitudinalthreaded bore which receivesdn threaded engagement thev inner threaded end of theabutment element |64.

`The abutment elements round at its outer end and is ,provided `with flat surfaces as indicated at |04`adja`cent to the outer end to facilitate adjustment by a wrench The retaining plug |06 ispressed into the innercnd of sleeve memberflll?.` The sleeve member |02 is further provided witna flange |08 at its inner end. An element return spring |09,"b'earing at one end againstthe framemember 65 and at its other end against the sleeveflange, resiliently` opposes the expansion ofthe element 84 and holds the datent constantl'ywin contact: with the movable wall of the inner cupl member 85.` The abutment member |04 is projected by the expansion of element 84 under certainconditions, `as indicated in Fig. Lto overlaythe upper fend of the valve stern and to` hold the valve elements open.` The nange 5l onthe upper end of the valve stem provides a projecting surface which `facilitates a definite tripping action and eliminates the possibility of the` detent draggingon the stem at the moment of tripping. c l f Operation of the device c Fig. 1 shows the elements ofthe device. in the position to which they automatically move upon loss of ame at the pilot burner. The detent |04 is in a retracted position, clear ofthe flange 5l' on the upper end of the valve stem 56. The de` tent was-moved to thisposition bythe element return spring |09 as condensation of the vapor in v bulb 2| progressedafter loss of pilot flame. Valve elements `4l) and 4|.lare both'closed, and the valve stem 56, the sleeves 60 and 6L are moved to their uppermost position by 4the `,main valve return spring154. `Inthis position the counterspring 64 isV compressed `by the. much stronger spring 54. The manuallyoperated'reset plunger 59 and the lockout latch 16 are in their normal positions, to which theyare returned by springs 'i4 and 'i3 respectively. i .l l v c i In order to relight the pilot burner and admit fuel `to the main burner, the .lmanual reset plungerise fully depressed to the position shown inFig. 3, whereinthe valve stem and hollow stem portion 43 of the valve element 4| are bottomed in thebore 52 of the closure plug 50. This action moves ithevalve element-4| to anopen position and placesthe upper `endof` the valve stem 56 slightly below` the lower edge of the detent abutment element |04. Asthereset plunger is moved downward however, the initial `part of the movement, that is;1thatpart of the movement which thelock out latch to` engage` the groove 02 in the upper sleeve member` 60.` K It willbeseen that with the sleeve member `6|) `and lconsequently the l i stressed cunterspring 64 thusretained, themain valve element 42, remainson its seat, by reason of the relatively light spring 55, asmthe valve Stem continues downward to depress the main spring ,c 51|` and open the valve'element 4|. Fuel may now flow from the supply line 23'into`the valve 24 bulb 2l' peintes Ve bei-le elieiiieee Si elie'fveeeiiee. to lelie upper eiiil: el llieelielll reirieiiieeir ei llie lieiiisi. elieieie erle enligne., e. llieexeelielele e let1ie1 il.llly

es. ele. eet 64 en ilse ile-teilt, eeeellllely merge energie. end 'the' epee "elle eleiiieee 1,114. is ieee-ee, inte eeeitieii.. eter? the, edge el elle fleiige el Q11. the livret eed ef; elle relie. Steel 5,6, eliewii iii Fig "el Wlieiele ll, Prevents ille lliiweiffl Wlleii tlile. eeiifs elle ee eee the neiiiielreeei plunger is rele'eeee te reliure, iiiiiiei; ereeeiire. el? 2g Seeing le toits iipieeriiieeii.; iieeiiiel 'positiesle leieli ie reeel leieliiiig elle. le leeres ellliel the; greet-e l? f eleeef ieg ilie'sleere meneeril llee ieleese el the ele-eve'ifiiemeer elle eeiiatereprifiig it wliieli. Wee stressed by the stronger main spring 11, moves the inner valve element 40, controlling the main burner port, toits open position; and compresses the relatively lig-hts'pring 55, as showninrFig.' 4.

Fuel may now iowi through the port 36, through the outlet 32, and the conduit 26 to the main burner when rquirementscause the valve 2ll to open.l The valves 4-0 and 4l will remain in this open and set position until the flame at the pilot burner "failsfor the fuel supply4 pressure drops below1 a predetermined point wherein it will not support a suitable flame' to insure sate and dependable ignition of the main burner. When the flame at "the pilot bnrner fails or diminishes below a predetermined point, condensation will take place in bulb chamber: 9i and element return ,spring IUS will displace theliquid mercury from the element @il and retract' the detent. When the detent is withdrawn suiii'ciently to clear the edge of the valve stem head 51, both valves will be quicklyolosed, cutting oifall fuel to the burners. The valve stem 56"and the sleeves '6g and 6I will also be returned to their uppermost positions and the counter-spring 64 eeiiiiir'seeelj igafltisfactory operation oi the device requires that the entire vbulbr chamber 9i be heated sumcientlv bythe pilot flame to displace all yliquid therefrom so tllat the point of continued boiling will occur" inthe greatlyrestricted capillaryy tube. Iltuwill benoted that the llame port and bulbI are soar-ranged to effect this. If boiling continues the enlarged chamber 9| it will cause the 'eseelieilele' elellllelll le llb'l'el'e ebieelleiieblv- It wir anche tiene@ that the single @Peeing iii ilie ehemlier elle elite levee? Peint '1li llie. eiiefllilg is not at elle lowest peint Will ee'iitiriiile te gigviigie'iiiie the elleiiieer elle eeeileee le beilf therein eeiieliig e eeiiiiiiiielle eiiiel'oe ei the. eiiieiielble element-l The boiling mint 0f mi@ mu'y and hl* ieee. the' ieiiipereiiiie el vlileli the deieiii, will lie 8 eel etes 112er lee Verleger varying the Strength ef: llie e neet geteilt meteo-"eigenen 1:11a i1 111111111gg-1eu1b'1g11ggraturein'egcess of @0Q2 Fytfoy move the detent to a see pesiizieii orte relelri il. liife eef eeeieieii- Thief temperatures without danger of being aiected by ambient temperatures, the spring load on the expansible element may b e decreased and a more economical pilot llame may bel used.

The time, interval between ignition of the pilot burner and the. movement of the detent to a set position, is, of course, not very critical, but it should not, as a mattery of convenience, exceed one minute. This time interval will vary. somewhat depending upon the temperature'of the bulb at thetime of ignition, the spring loading of the expansble element which' determines the ternpeature v'vhilfl` the bulb must attain, the design ofthe flame port and the fuel supply pressure, ang 'the' adjustment 'of' the abutment element relative'to the valve stem head.

The ti e'ntelval between flame failure and the tripping of the'devlceig'mor critical, howeveit, te the' extent etlee'ei? 'lliee ehe'devieedeeg iie'e title trefle elementair illels'eil'iig' ei ilieileiie due e0 draft, er liririiitlllee' lll the f llelfelllslfle the extent. 'eli te 'maximin period based en gefeit 4911s muet be lexeeeeeelf "llie ebuimeiii element ie efliiieieel ilieieiere to satisfy llieee requirements- T lieeeriiig leerling ei ehe. element will elee'eeteriiiiiie elle llmeiiitervgi bef t'Ween fleiii'e feiliire 1.1.1111 tripping! Aefllie iiiiiii-Y mum temperature at which the device Will set or trip is raised by increased spring pressure, the dif# terential between this predetermined minimum and the maximum stabilized bulb temperature attainable with the llame will 4'diminish and therefore, the time interval onY cooling' will dlmiknisxh'i The ebiilllleee. eleiiieiie hee beeiierreriged ie leleeeeee erisl e tenere@ eiirfeee 51e er1 ille under Slele 0l lille, heed 51 heg been provided le allow for the natural inclination of lthe operator to feel for the abutment element. If, after the pilot has been ignited he releases vthe manual reset plung-A er slightly, just sufhciently to move the head 51 above the abutment member at a time when it is just approaching the. edge of the head, it would be impossible for him to again fully depress the plunger after a short interval without this provislon.

'1 -he foregoing description is intended to be illustrative and not limiting and the exclusive use f al1 modifications within the scope of the ap. i vblended claims is contemplated. e

r1 eleliili l; ln'a manual reset valve in combination, a valve body having main and Y"pilot 'burner fuel supply ports thereinf'rst and second valves for eeiiliiellleg eeie eieii'if eii'eleilei eerie fessee-tively. e iiielll epilee ffei lieleiiig ejgd gegend' ifeive, eleseil e eeeelleleiv enriiisbieged between said seeeiie eee e waives' i917 heldijiigsgid orsi valve lQQd. fel 5, ,g `returned manual actuator for opening said second valve, a counter spring' Capable of opening said rst valve against said seceiieerv epilee, weer .Seid .Seeeiie velve is.y opened, ieeane' eiierelee live ieeiiiigi'egiu'gibr as'it'is moved in a valve opening direction to restrain ll'lieebleeli.' found de rable to sprn load the expansible elein," coming inoperative upon'returniofsaid manual actuator, andmeans operative under certain conditions to hold said; second valve in an openposition.

valve body having main and pilotyburner `fuel supply ports therein, iirst and second valves for controlling said `main and pilot ports respectively, almain spring biased between said valve body and said second valve for holding it closed, a secondary springlbiased `between said second and iirst valves forI holding said iirst valve closed, a spring returned manual actuator for opening said second valve, a spring pressedmember capable of opening saidiirstvalve against said secondary spring when said second valve is opened,

`ailatch member moved to a position forl restraining said spring .pressed member as said manual operativel under certain conditions to hold" said second valve in an open position.l i l 3. In a manual reset fuel valve in rcombination, a valve body .having main and pilot `fuel supply ports therein, rstiandsecond valvesfor controlling said main `and pilot ports .respectively, a main spring biased between said valve body and said second valve for holding it closed,

a secondary spring biased between said second f and iirst valves for holding said first valve closed, a spring returned manual actuator for opening said second valve, said actuator having a lost motion connection with said second valve whereby said actuator may be moved an initial amount in a valve opening direction before said second valve is moved, a spring pressed member arranged to contact said iirst valve and move it to an open position against said secondary spring when said second valve is opened, said spring pressed member being restrained by said second valve when in a closed position, means rendered operative by the initial lost motion movement of said manual actuator in a valve opening direction to restrain said spring pressed member, said restraining means being rendered inoperative upon return of said actuator, and means operative under certain conditions to hold said second valve open.

li. l'n a device of the class described, a valve body having an inlet, a main outlet, a pilot outlet, a wall separating said inlet and main outactuator is moved in a valve opening ldirection, i said latch member-being moved to a releasing position as said actuator isreturned, and means tion. apilot burner, `a `valvebody having main and pilotfuel supply ports therein, `iirst and sec- 4ond y valves `for` controlling wsaid` main and pilot .1 i i ,i ports respectively, a main spring for holding said 2. In amanual reset `valve-in combination, a 5

secondfvalve' closedgnriai:r secondary springwfor i holding said first valve; closed, aspring returned manual `actuator `forfopening said second valve, said actuator having. aglost, motion connection withsaid secondvalvepwhereby` said actuator` may `bemoved an initial amount in a valve opening direction before saidsecond-,valve is moved,

`agspring pressed memberarranged to Vcontact said iirstvalve and tomoveitto an open position against `said secondary spring when said. second valve is openedssaid springpressed member being restrained by saidasecond valve whenit :is

in a closed position, `means rendered operative by the :initial movement of saidmanual actuator in a valve opening `direction toarestrain said spring `pressed member, said restraining means being rendered inoperative; upon return of said i actuator, and a flame sensitive device responsive to `flame `at said pilot burnerfor holding said ya pilot outlet,v a wall `separating said` inlet and let, a main burner fuel supply port in said wall connecting said inlet and main outlet, an inner valve seat surrounding said port, an annular recess in said wall circumscribing said inner valve seat and having communication with said pilot outlet, an outer valve seat surrounding said annular recess, said valve seats and recess being on the inlet side of said wall, an inner disc valve adapted to engage said inner seat, an outer cup shaped valve adapted to engage at its rim with said outer valve seat, a relatively strong main spring biased between said valve body and said outer valve for holding it closed, a relatively light secondary spring biased between said outer and inner valves for holding said inner valve closed, manual means for opening said outer valve, said secondary spring being capable of retaining said inner valve in closed positionwhen extended by the opening of said outer valve, and counter spring means of intermediate strength for opening said inner valve under certain con ditions when said outer valve is open.

5. In a manual reset fuel valve in combinamain outlet, a main burner fuel supply port in said Wall connecting said inlet and main outlet, an inner valve seat surrounding said main port, an annular recess in said 'wall circumscribing said inner valve seat and having communication with said pilot outlet, an outer valve seat surrounding said annular recess, said valve seats and recess being on the inlet side of said Wall, an inner kreciprocating valve adapted to engage said inner valve seat, an outer reciprocating valve overlaying said inner valve and adapted to engage said outer valve seat, a relatively strong main spring for holding said outer valve closed, a relatively weak secondary spring for holding vsaid main inner valve closed, a spring returned manual actuator for opening said outer" valve, counterspring means of intermediate strength opposed by said main spring and 'being arranged to open said inner valve against said secondary spring when said outer valve is opened, means rendered operative upon initial valve opening movement of said manual actuator for restraining said counterspring means, said restraining means being rendered ineffective upon return of said manual actuator, and `means operative under certain conditions for holding said outer valve open. p

7. In a manual reset valve in combination, a valve body having main and pilot fuel supply ports therein, a posterior valve for controlling said main port, an anterior valve for jointly controlling both ports, a relatively strong main spring foriholding said anterior valve closed, a

relatively light secondary spring for holding said means, said latchl member being moved to a releasing position upon return of said actuator, and

holding said anterior valve open.

vmain Izar-1a ep'ilut parts, `@am eater vawefhaving a concentricdownwardly 'extending 'cylindrical iperfbonv :with a elosedulewer end, '2a fSereW 'threaded bore-concenttic withl'sad valveiseats in the ower #spr-mg feasffor lhldingfsafa sauver 'valve rles-ed,

valve elosed. tirens f'ftxr find'perfdertly fpenihg said outer valve, means'operable under certain :conditions :for opexxrg said "inner `valve when saidzouter 'valveV is Iapen; and means dnf'sadfou'ter valve .for rendering s'ai'd last mentioned `means inoperative sad outr valve Fis c1o`sed.

OIEFTGN fA. 'COBB .REFERGES GITED fm1-lewin@ are lef aerfo im an@ `fiile ibf patent. A