US2726716A - Safety control for gaseous fuel burners - Google Patents

Description

Dec. 13, 1955 w. J. RUSSELL 2,726,715

SAFETY CONTROL FOR GASEOUS FUEL BURNERS l Filed Dec. 30 1950 2 Sheets-Sheet l w il M JNVENTOR.

JLLIHM J. Pasa-LL Dec. 13, 1955 w. J. RUSSELL 2,726,716

SAFETY CONTROL FOR GASEOUS FUEL BURNERS Filed Dec. 30. 1950 2 Sheets-5h66?. 2

a a@ 5@ a j INVENTOR.

--r 11.1.1.4@ J. PassELL.. i 9.

United States Patent O SAFETY CONTROL FOR GASEOUS FUEL BURNERS William J. Russell, Jeannette, Pa., assiguor to Robertshaw- Fulton Controls Company, Greensburg, Pa., a corporation of Delaware Application December 30, 1950, Serial No. 203,648`

3 Claims. (Cl. 15S-130) This invention relates to safety controls for gaseous fuel burners and more particularly to ame responsive controls for cutting off the supply of fuel to the burners in the event of ame failure.

In fuel controlling devices of this type, it is desirable to maintain a safety valve and a pilot valve open in the presence of a pilot ame and closed in the absence thereof. To this end, in the present invention, a ame responsive safety valve and a pilot valve are interconnected so that opening and closing of the safety valve causes corresponding opening and closing of the pilot valve. To provide an initial supply of fuel to establish a pilot flame to which the safety valve may respond, manually operable means cooperate with the means interconnecting the safety and pilot valves to open the pilot valve while the safety valve is closed.

In safety control devices of this type, the safety valve must pass a maximum volume of fluid with minimum throttling action when in the open position. However, with thermally responsive actuating mechanisms now known in the art, the practical amplitude through which the valve member of a safety valve can be moved is limited to a relatively small distance. Accordingly, the amount of uid fuel which can pass through such a valve is limited by the size of the aperture formed between the valve seat and the valve member when the valve member is in open position. In the present invention, a plurality of valve seats cooperate with the valve member to provide a plurality of apertures through which the fuel may flow thus increasing the effective passage area of the valve without increasing the diameter or amplitude of movement of the valve member.

it is an object of this invention to cause complete and automatic shut off of all fuel to both main and pilot burners when the pilot ame is extinguished.

Another object of this invention is to permit ow of fuel to the pilot burner during the starting operation while preventing any ow to the main burner.

Another object of this invention is to permit control of the pilot valve by manually operable means during the starting operation and by the ame responsive safety valve during other operations.

Another object of this invention is to pass a maximum amount of uid through a valve structure.

Another object of this invention is to eliminate throttling in a fluid controlling valve structure.

Another object of this invention is to increase the eifective area of the uid passage in a valve having a given size valve member movable through a given amplitude.

Another object of this invention is to arrange the control in compact form as a unitary construction which is adapted for manufacture at low cost and which will occupy a small space when installed in a gas appliance.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings wherein:

Fig. 1 is a schematic view of a safety lcontrol device 2,726,716 Patented Dec. 13, 1955 ICC embodying the subject matter of this invention shown in conjunction with a gaseous fuel burner;

Fig. 2 is a schematic view of the control device shown in Fig. 1 with the parts thereof in dilerent operating positions;

Fig. 3 is a schematic view of the control device shown in Fig. 1 with the parts thereof in still another operating position; and

Fig. 4 is a sectional view taken on the line lV-IV of Fig. 1.

Referring more particularly to Fig. 1 of the drawings, a main burner 10 is shown for location in a conventional gaseous fuel burning heating device (not shown). The main burner 10 is supplied with gaseous fuel through a pipe 12, the flow of fuel of which is under the control of a suitable thermostat 14 and a safety valve mechanism indicated generally by the reference numeral 16.

Disposed in igniting relation with the main burner 10 is a pilot burner 18 which is adapted to be supplied with fuel through a conduit 2t). Flow of fuel to the pilot burner 1S is under the control of a pilot valve indicated generally by the reference numeral 22.

Actuation of the safety valve and the pilot valve is eifected by condition responsive means here shown as a thermomagnetic device 24 adapted to respond to the presence or absence of a flame at the pilot burner 18 and positioned to be cooperable with the safety valve 16 and the pilot valve 22. n

The safety valve 16 and the pilot valve 22 are carried by a casing 26 which is provided with an inlet chamber 28 and an outlet chamber 30 separated by a partition 32. Communicating with the inlet chamber 28 through an inlet opening 34 is a pipe 36 which is connected to la source of fluid fuel supply (not shown). Communication is maintained between the outlet chamber 30 and the thermostat 14 by a pipe 38 which extends through an outlet opening 40 formed in the casing 26.

The partition 32 is provided with a valve opening 42 through which the inlet chamber 28 is adapted to be piaced in communication with the outlet chamber 30. The valve opening 42 is preferably annular in form but may comprise an annular row of ports. Surrounding the valve opening 42 and carried by the partition 32 is a valve seat 44, and also carried by the partition 32 radially inward of the valve opening 42 is a second valve seat 46. A cylindrical boss 48 is formed on the partition 32 radially inward of the valve seat 46 and is provided with a cylindrical recess for slidably receiving a valve stem 52 to which is secured a valve member 54.

That portion of the valve member 54 adjacent the periphery thereof is imperforate and forms a seating portion adapted to engage the valve seats 44, 46 to interrupt communication between the inlet chamber 23 and the outlet chamber 3i). The central portion of the valve member 54 is pierced by a plurality of bores 56 which serve as passages for maintaining communication between the inlet chamber 23 and the space beneath the valve member 54.

interposed between the valve member 54 and the partition 32 is a spring 5S which serves to bias the valve member away from the valve seats 44, 46 and into engagement with a iiexible diaphragm 69 which closes the open end of the casing 26 and serves to 4seal the casing 26 against leakage at this point. The thermomagnetic device 2li is positioned on the side of the diaphragm 60 opposite the safety valve 16 and serves to position the valve member 54 either in its biased position or in engagement with the valve seats 44, 46.

When the valve member 54 is in its biased position as shown more clearly in Fig. 3 of the drawings, the valve member 54 will be spaced from the valve seats 44, 46 and the valve seats 44, 46 will coact with the valve memame-#1e ber 54 to effectively form a-pair of annular orifices. The annular orifice defined by the valve member 54 and the withptrhe free end 78 of the main lever 76 when the arma- Y Y valve seat 44 will be in direct communication with the Y Sineterarnbrezs 'anemie enterrar annee [defined "ey the closed, the capacity is determined by the area of the ori- Y"-iice by'the valve-member and rthe valve seat :when

thervalve member is in open position, it will beap'pr'ent '-thattth'eoi'iiice'faeaffrfa givemarialdisplacement'of'the valve "member "is :substantially increased "byithe #provisionofalplnrality f'valvefseatsand by the provision of n lrlfrefvave'amena'15er'tofinsnre the maime- 'n'ance-offccsnfmnnicat'ion ee`t\Ne'en`-all the orifices and the inlet'chambera's., y

' ThepilotvalveZvmay comprise'fa generally cylindrical VpilotvalvecsingElsnitablysecured to the'casing 276 lat- "erallyof the safety vaivel' 'andprovided with'a centrally7 disposed 'valve "opening "674 in communication With the VY"inlet"chamber 2S. "A valve seat '66 Acarried by thepilot valve casingr62`'sr'rndstlie valve opening 64 and is mnication `betvven'the'valve opening 64 and the inlet chamberfZS. l l Y Extendinglthrongh' the'valve opening 64 is a'valve stein :68 which carriesV the' valve disc'ii on one end. 'Secnredto the othervend of the valve stem @Shy any suitable vrinidltight'coi'xplingis a exible Idiaphragm 7) which has Vits peripheral-portionsecred to the pilot valve casingf?n Y :by fairy sflitabl'e"means "to seal the casing 62 against leakage'fat this point. "The valve dis'c'67 is biased into en- 'c'ornectedto the lvalve 1:stein `63 and engaging the 'casing T52; '5A bore -74"is-foi11edin the wallof the' casing 62 to receive nend f't'he condit Zvfand thereby'establish Vcorninnnication'betv'v'eenthe'pilot burner I8 and the valve @einem Y Y Y n is fdsifabie marfhefp'irer vaivezz beset in a fuel siich ya po'sitin'softhat the safety devicewill be effective motion? tbes'af'e'ty valve7meniber to the Y v'pilot valvefiso" that movement of the valve member 54 of'thefpiltvalve't a nstthe'biasor thespring 72. Thisni'ans inay'take'the l m ofafmain lever "76 having its end'portions 78,80 loverlying the safety valve i6 and l"the pilot valve 22 respectively. The lever 76 is lpivoted intermediate its ends'at Si on a lng S2 depending from an Vauxiliary leverf'. One vend of the auxiliary leverl 34 is Y 'pivoted at en -a' housing"S7 secured to the casing 26 byanysuitable-means. 'Pivotal movement of the lever 84 about litsV pivot 1851 isefected byV manually Yoperable frieansoperatively?associated with thefree end thereof as will more fnlly appear.y

Y The thermornagnetic device V24 is here shown ascoli*-Y V'"prising 'an'e'lecrornagnet 96, its associated winding "92 'and armature 94.

recess '98 Aformed in the Yhousing'S inV axial alignment withlthe nafety'valve l16. Y The armature $4 is nionnted 'in Y"tlieicage"967for'niovement relative to the magnet 9d and is fp'rvided'fivih acylindricale'itension 99, which entends ith'ronghva cyiiildrical k'guide element "t'foimed in the lowerportien of the cage 96, and 'into engagement with '-tie endportio'n7?. ofthe main :lever 7e. y Interposedbetweenethe cage 96 and a collar tZ formed in 1th Xt'enrsion'9`9of the ar'inatrire"94lisV a 'spring 194 The electromagn'et 9% is YsecnrelyV V[mounted vin'a cage 95 slidably carried yin a cup-shaped ture 94 is in its free position as shown in Fig. 1 of the drawings. The spring 1043is of such strength that it will force the free end 78 of the lever 76 into engagement with the diaphragm 6i) to move the valvemember 54 against the bias of the spring BSandinto engagement'with the valve .seats @4, 46.

normally retalin'el "in 'engagement with g'a'cting'between the cage 96-and-'a'ninternal flan-gent) 'carried'by tie i1ousing87. Interposibetwee'n'the-spring 19% and the cage 96 is the free end'bf the auxiliary lever 84. [he free end 38 o fthe lever 84 is thus lretained in engagement lvith -liezfge 96"rd'is'mvablethri'ith. As best showninFig. "4, tlie angel may be Yformed with a gap 112 therein to insure freedom of movement of the main lever 76.V *Y

The winding gfandthe'fmagnetareenergiediby a rthermoelectric'device lhere shovvna'sa -therrnocouple "11?44 .positioned vto be"e'Xp'os'ed"-"to `a flame emanating from-diie pilot burner 18. An electric current 'generate'd by the tiierr'nocople 1'4 isgeilerallyv'insufficient"toV attracttne armturej94'but 'isicapable Vofretaining it attracted vposition after Yit has been freset in 'such position.

vided and 'takes the'form "of 'a push button `116 vslidably frcessQS 'in the"l1ous'ing7. '-To'retain'thepsh button l-inposition,` the'oxiter'end ofthe bore y'111% is reduced to provide asholder vtladapted `to `abut a ila'nge 3122 formed on'the push-button "'1'16. Y

Thecake 9e isf'niaintainedfinengagement with the pnsh button H6 by Vthe biaas of the spring 138 and movement Vof "the lpush btton Willeiecta'corresponding `movement With the airmatnreli'94. V5Dofvvftvvard movement Vof the cage 95 will c 'aliisefconiiter'clockwise -rnovement Yothe fanirilarylevr to eie'ctf'a' Igeneral downward movernenllof'thepivoty 'slof themain lever76.V `Since vthe 'end '73 of thefmzainleverh' isfrestrainezd from vertical movement Ythe. armatre 94 fand 'fthe valve member V54, dvvn'vvard' lm'ove'rrient' the p'ivot *Si jvvill L'eiect fclock- 76 about the vend 78fther`eof n ted by `tlieu pilotam 1l"l generate an :electric cnr- 'A arianna-'6em 'inf Figs;Ttiaing-thefspring-104 in a Ycdm-V jfhepnsh button maywnovvrbe released to permit'the moved 'nde "the bias of 'the "spring-into l*engagiertzentjtljendvl/ail1%.Y *Since the ind'ing Y tis energized the 7afrnatnre ted" pos'itionfand 'willy :nove the nagnfet to "the posi- Con?z sequently', manually voperable 4resetting 'means 'is pro! 96 and the electromagnet 90 will remove the restraining force from the valve member 54 of the safety valve 16 and permit the valve member 54 to move away from the valve seats 44, 46 under the bias of the spring 58. It is to be noted that although the pivot 81 of the lever 76 is moved upward upon return of the cage 96 to its normal position, upward movement of the valve member 54 will cause an upward movement of the end 78 of the lever 76 to pivot the lever 76 about the fulcrum 81 in a clockwise direction to maintain the pilot valve stem 68 in depressed position with the valve disc 67 out of engagement with the valve seat 66. The various parts of the control device are now in position for steady state operation and are as shown in Fig. 3 of the drawings.

Upon failure of the flame at the pilot burner 18, the thermocouple 114 will cool terminating the supply of electric current to the winding 92 of the electromagnet 90. The deenergized magnet will release the armature 94 which will be moved under the bias of the spring 104 to move the end 78 of the lever 76 and the valve member 54 of the safety valve 16 downward. The lever '76 will be moved counterclockwise about the pivot 81 to permit the valve stem 68 and its associated valve disc 67 to move upward under the bias of the spring 72 thus causing the valve disc 67 to engage the valve seat 66 and cut oi the supply of fuel to the pilot burner 18. Simultaneously, the valve member 54 will be moved against the bias of the spring 58 into engagement with the valve seats 44, 46 to cut olf the supply of fuel to the main burner 10. The various parts of the control device are thus positioned as shown in Fig. l of the drawings and no fuel can ow to either of the burners.

It will be understood that many changes may be made in the details of construction and arrangement of parts without departing from the scope of the invention and that this description and accompanying drawings are intended by way of illustration only and are not to be construed in a limiting sense.

It is claimed and desired to secure by Letters Patent:

l. In a safety control for gaseous fuel burners having main and pilot burners, the combination of a main valve biased to open position during normal operation of the burners for controlling the Supply of fuel to the main burner, a pilot valve biased to closed position for controlling the supply of fuel to the pilot burner, a lever having a pivotal support and being operatively associated with said main valve and said pilot valve, said lever being constructed and arranged to hold said pilot valve in open position while said main valve is in open position, an electromagnet, a thermoelectric device located to be heated by a ilame at the pilot burner for energizing said electromagnet, an armature mounted for movement relative to said electromagnet, said armature being braised to the free position thereof and adapted to hold said main valve closed in the free position thereof while permitting said main valve to assume its biased position in the attracted position thereof, manually operable means for moving said electromagnet into engagement with said armature to attract and hold said armature in attracted position, and lever means movable with said manually operable means for moving said pivotal support to position said lever to overcome the bias of said pilot valve during operation of said manually operable means while said main valve is in closed position.

2. In a safety control for gaseous fuel burners having main and pilot burners, the combination of a main valve biased to open position during normal operation of the burners for controlling the supply of fuel to the main burner, a pilot valve biased to closed position for controlling the supply of fuel to the pilot burner, a first lever, a second lever pivotally mounted on said first lever and being operatively associated with said main valve and said pilot valve, said second lever being constructed and arranged to hold said pilot valve in open position while said main valve is in open position, an electromagnet, a thernloelectric device located to be heated by a ame at the pilot burner for energizing said electromagnet, an armature mounted for movement relative to said electromagnet, said armature being biased to the free position thereof and adapted to hold said main valve closed in the free position thereof while permitting said main valve to assume its biased position in the attracted position thereof, manually operable means for moving said electromagnet into engagement with said armature to attract and hold said armature in attracted position, and means movable with said manually operable means for moving said flrst lever to position said second lever to overcome the bias of said pilot valve while said main valve is in closed position.

3. In a safety control for gaseous fuel burners having main and pilot burners, the combination of a main valve biased to open position during normal operation of the burners for controlling the supply of fuel to the main burner, a pilot valve biased to closed position for controlling the supply of fuel to the pilot burner, said pilot valve being disposed laterally of said main valve, a rst lever, a second lever pivotally mounted on said first lever and arranged in overlying relation with said main valve and said pilot valve whereby forces are transmitted from said main valve to said pilot valve to hold said pilot valve open while said main valve is open, an electromagnet, a thermoelectric device located to be heated by a flame at the pilot burner for energizing said electromagnet, an armature mounted for movement relative to said electromagnet, said armature being biased to the free position thereof and adapted to hold said main Valve closed in the free position thereof while permitting said main valve to assume its biased position in the attracted position thereof, manually operable means for moving said electromagnet into engagement with said armature to attract and hold said armature in attracted position, and means movable with said manually operable means for moving said irst lever to position said second lever to overcome the bias of said pilot valve while said main valve is in closed position.

References Cited in the le of this patent UNITED STATES PATENTS 2,290,108 Mantz July 14, 1942 2,333,261 Mantz Nov. 2, 1943 2,363,073 Mantz Nov. 2l, 1944 2,387,164 McCarty Oct. 16, 1945 2,414,220 Alfery l an. 14, 1947 2,447,668 Ray Aug. 24, 1948 2,455,542 Weber Dec. 7, 1948 2,457,492 Raybould Dec. 28, 1948 2,513,705 Arden July 4, 1950 2,523,864 Delany Sept. 26, 1950 2,590,674 Bodey Mar. 25, 1952 2,604,107 Huntington July 22, 1952

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