US3167250A

US3167250A - Valve tilting means for a burner fuel control system or the like

Info

Publication number: US3167250A
Authority: US
Inventors: Wantz Clarence; Charles D Branson; Roy C Demi
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1961-11-17
Filing date: 1961-11-17
Publication date: 1965-01-26
Anticipated expiration: 1982-01-26

Description

c. WANTZ FETAL 3,167,250 VALVE TILTING MEANS FOR A BURNER FUEL. CONTROL SYSTEM OR THE LIKE Filed Nov. 17, 1961 4 Sheets-Sheet l m m a A u n m m T Q Q 6 m m mv v I J/ mm m m mm wmm mm ww g 1 Hm I M O rlllalk CCDH mm mm Y B I\ rlr l\ mm H MN I lllll l I Wm N mm vm omoooooo mm vm m: m9 5 mm NJ m9 vm mo r. l I l |||x l I ll Om Jan. 26, 1965 ATTORNEY Jan. 26, 1965 c. WANTZ ETAL 3,167,250

VALVE TILTING MEANS FOR A BURNER FUEL CONTROL SYSTEM OR THE LIKE Filed Nov. 17. 1961 4 Sheets-Sheet 2 FIG-2A INVENTORS CLARENCE WANTZ CHARLES D. BRANSON ROY c. DEM! ATTORNEY Jan. 26, 1965 c. WANTZ ETAL 3,167,250

VALVE TILTING MEANS FOR UR FUEL.

CONTROL SYSTEM OR LI Filed Nov. 17, 1961 4 Sheets-Sheet 3 BY ROY C. Ml

ATTORNEY Jan. 26, 1965 c. WANTZ ETAL VALVE TILTING MEANS FOR A BURNER FUEL CONTROL SYSTEM OR THE LIKE 4 Sheets-Sheet 4 Filed Nov. 17, 1961 FIG-l3 INVENTORS CLARENCE WANTZ CHARLES D. BRANSON ROY C. DEM] ATTORNEY United States Patent 3,167,250 VALVE TILTING MEANS FUR A BUR FUEL CONTRQI. SYSTEM OR THE LIKE Clarence Wantz, Charles I). Branson, and Roy C. Demi,

all of Greensburg, Pa, assignors to Robertshaw Controls Company, Richmond, Va, a corporation of Delaware Filed Nov. 17, 1961, Ser. No. 152,998 14 Claims. (Cl. 236-468) This invention relates to systems for controlling the flow of fuel to burners and the like, such as a domestic gas oven burner to maintain a preselected temperature within the oven. This invention also relates to improved parts for such systems and the like.

Heretofore, the temperature of an oven or the like has been controlled by utilizing a control valve that thermostatically throttles the flow of fuel to the oven burner in response to the temperature of the oven. However, such a control valve is normally provided with a by-pass so that when the thermostatic valve is closed a sufficient amount of fuel is permitted to flow to the oven burner so that the gas will burn at the oven burner.

It has been found that this small by-pass flame burn ing at the main oven burner, when the main thermostatic valve is closed, heats the oven to such a temperature that the oven temperature cannot be maintained below 300 F., whereby there is no means for maintaining food and the like in the oven at a low warming temperature that will not cook the food.

However, according to the teachings of this invention, an improved fuel control system is provided for maintaining the oven temperature at a selected low warming and non-cooking temperature as well as providing a suitable control for maintaining the oven at normal cooking temperatures by utilizing a single main oven burner.

Accordingly, it is an object of this invention to provide an improved fuel control system having one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide an improved valve construction for such a fuel control system or the like.

A further object of this invention is to provide improved parts for such a valve construction or the like.

Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIGURE 1 is a fragmentary, schematic view illustrating the fuel control system ofthis invention.

FIGURE 2 is an enlarged, axial, cross-sectional view illustrating the improved valve construction of this invention utilized in the fuel control system of FIGURE 1.

FIGURE 2A is a fragmentary view similar to FIGURE 2 illustrating a modification of one of the valve members of the valve construction of FIGURE 2.

FIGURE 3 is a fragmentary, cross-sectional view of the valve construction illustrated in FIGURE 2 and is taken on line 3-3 thereof.

FIGURE 4 is an end view of the valve construction illustrated in FIGURE 2 and is taken substantially on line 4-4 thereof.

FIGURE 5 is a cross-sectional view of the valve construction illustrated in FIGURE 2 and is taken on line 5-5 thereof.

FIGURE 6 is a fragmentary, cross-sectional view taken on line 66 of FIGURE 5.

' FIGURE 7 is a fragmentary, cross-sectional view taken on line 7-7 of FIGURE 6 and illustrating the opening and closing movements of a valve member of the valve construction of FIGURE 2.

ice

FIGURE 8 is a side view of one of the valve members of the valve construction of FIGURE 2.

FIGURE 9 is a cross-sectional view of the valve member of FIGURE 8 and is taken on line 99 thereof.

FIGURE 10 is a view similar to FIGURE 9 and is a cross-sectional view taken on line 1010 of FIGURE 8.

FIGURES ll-l5 are schematic views illustrating the position of the cock valve of FIGURE 8 at various temperature settings of the valve construction of FIGURE 2.

While the valve construction of this invention and the improved parts thereof are illustrated as being incorporated in the fuel control system of this invention, it is to be undertsood that these features of this invention could be utilized in other systems, as desired.

' Therefore, this invention is not to be limited to only the embodiments thereof illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIGURE 1, the fuel control system of this invention is generally indicated by the reference numeral 20 and is adapted to selectively maintain the temperature in the oven 21 at any selected temperature through a range of low warming and non-cooking temperatures as well as through a range of high cooking temperatures by utilizing a single main oven burner 22 in a manner hereinafter described.

For example, the fuel control system 20 of this invention is adapted to maintain the temperature of the oven 21 at any selected temperature from F. to 550 F., while conventional fuel control systems are not adapted to maintain the temperature of a particular oven below approximately 300 F.

The fuel control system 20 comprises a source of gas or other fuel maintained in a manifold 23, the manifold 23 being interconnected to a continuously burning standby pilot burner 24 by a conduit or passage means 25.

The passage means 25 has a suitable filter and adjusting valve arrangement 26 to maintain the flame 27 of the standby pilot burner 24 at the proper level, the standby pilot burner 24 being adapted to ignite fuel issuing from the main oven burner 22 and a controlled pilot burner 28 in a manner hereinafter described.

A valve construction 29 of this invention has an inlet 30 thereof interconnected to the manifold or source of fuel 23 and an outlet 31 interconnected to a main conduit or passage means 32 leading to the main oven burner 22, the passage means 32 having a safety valve means 33 disposed therein and controlling the flow of fuel to the main oven burner 22 in a manner hereinafter described.

The safety valve 33 is adapted to open and interconnect the main passage means 32 to the main oven burner 22 when a flame 34 exists at the controlled pilot burner 28 the flame 34 heating mercury or the like in a sensing bulb 35 which causes a bellows arrangement 36 to expand and open a valve member 37 of the safety valve means 33 to interconnect the inlet 38 thereof with the outlet 39, the outlet 39 having an adjustable orifice device therein and projecting into an opening formed in the end 40 of the main oven burner 22.

The valve member 37 of the safety valve 33 is normally urged against the valve seat 41 by a compression spring 42, the valve member 37 having a stem 43 engaging a lever 44 pivotally mounted to a bracket 45 by a fulcrum member 46. The other end of the lever 44 is engaged by a lever 47 pivotally mounted to the bracket 45 by a fulcrum member 48, the lever 47 threadedly carrying an adjusting screw 49 passing through a suitable aperture in the lever 44 and disposed within a compression spring 50 disposed between the

levers

47 and 44 and tending to maintain the

levers

44 and 47 in the position illustrated.

In this manner, when a flame 34 exists at the coninside the valve member 56.

trolled pilot burner 28 in a manner hereinafter dev scribed, themercury in the bulb 35 heats up and vaporizes' Y causing the bellows 36 to expand whereby the lever 47 is pivoted downwardly about thesfulcrum means 48 and causes the lever 44 to pivot'upwardly about the fulcrum 'means 46,, the pivoting lever 44 carrying the 'valvemember 37 therewith away fromthe valve seat 41- to interconnect the main passage means 32 with the main oven burner 22 so thatfuelcan flow to the main oven burner I 22 and be ignited by the standby pilot burner 24. Conversely, when thejflame 34 ceases to exist .at the controlled, pilot burner 28, the. mercury in the bulb 35 condenses Wherebythe bellows 36 contracts to cause the

levers

47 and 44 to be pivoted back to the position illustrated .in FIGURE 1 by the force of a compression spring 42 closing the valve member 37 totprevent fuel from being supplied to the mainjoven burner 22.

The valve construction 29 is adapted to control the I scribed. 3

As illustrated in FIGURE 2, the valve construction 29 includes a housing 51 formedfrom two housing members 52 and 53 suitably interconnected togetherbyebolts I 54 or the like, the housing 51 havingta cavity 55 formed therein and interconnected to the aforementioned inlet .30 and outlet 31.

A. rotatable cock valve member 56' is disposed in a 'flowof fuel to. thetmain' passage means 32 and to the 4:

controlled pilot burner 28 in a manner now to be de-' tapering portion 57 of the cavity 55 and is adapted to' vcontrol communication between'the inlet and: the

cavity in a manner hereinafter described.

The valve member 56 has a longitudinal bore 58 pass-v ing therethrough and so constructed and; arranged that the bore 58 defines a pair of stepped shoulders;59 and,

An adjusting stem 61 is disposed the shoulder 59 to frictionally interconnect the stem 61 the valve member 56will' be imparted to'the stem 61.

in the bore v5 8 and has 7 a tapering surface 62 cooperable with the corner 63 of an inwardly bent tab 80 that is 'slidably disposed in a slot 81(FIGURE 4, of the valve member-5 6, the sleeve 79 being suitably splined to acontrol knob 82 having a removable plate 83 spring-pressed therein.

. A drive ring 84-is 'disposedbetween the housing 51 and the cover member 72 and has a pair of inwardly directed opposed tab means'85 slidably' disposed in opposed slots 86 formed at the right end of the sleeve 79.

The driverring 84 has va pair of perpendicularly bent outer tabmeans 87 respectively receivable in slots 88 posed; against ;the,drive 'n'ngy84 and the other end 93 0 thereof disposed against a retainer ring 94 carried by the housing51 and abutting the valve member 56 whereby thecompression spring91holds the valve member 56 into wedging relation with the tapering portion 57 of the cavity '55 and normally holds the drive ring 84 against the cover member 72whereby the tabs 87'. of the drive ring 84 project through the slots 88 of thecover member 72 to prevent rotational movement of the control knob 82 and thereby prevent rotational movement of the valvemember56. I f

However, when it is desired to rotate the valve member 56 theloperator axially Ipushes thecontrol knob 82 to the right whereby'the sleeve 79 carriestthe drive ring 84 to the right in opposition to the force of'the compression spring 91 until the tab means 87 of the drive ring 84 have cleared the slots: 88 of'the cover. member 72 to permit the control knob 82 to be rotated. Rotational movement of the controlknob 82' causes the sleeve 79 to rotate in unison there- 7 with whereby the tab means 80 of the sleeve 79 and the .to the valve member 56 so that rotational movement of 7.

In particular, a retaining ring 64 is disposed in'an annular groove65' formed in the stem 61 and is retained thereon by a split ring 66 whereby one end 67 of a compression spring 68 bears against the retaining ring- 64 and has the other end69 thereof disposed'against a're-,

taining ring 70 compacting a seal 71' against the shoulder 60 'ofthevalve member 56 to prevent fuel leakage between the stem 61 and valve member 56.; I

In this manner, the compression spring 68 tends to urge thestem 61 to the left as viewed in the drawings to frictionally wedge the tapering surface 62 of the stem 61 into driving relation with the corner 63 of the shoulder 59 of the valve member 56 whereby rotational movement 1 unison therewith.

However, the stem 61 can be disengaged from the,

of the valve member 56 causes the stern61- to rotate in valve member 56 byaxially moving the stem 61 to the I 1 right in opposition to the force of the compression spring 68 whereby the tapering surface 62of the'stem 61 will-i'i be disengaged from the corner 63 of the shoulder 59 of the valve member 56 for the purpose hereinafter deseribedx The valve member 56 is adapted to be rotated in the housing 51in the following manner. a

A cover member 72,"FIGURES 2, 3 and 4, has an outwardly directed annular flange 73 provided with 0pv in the off'position.

As i-llustratedfin FIGURESS-IO, therotatable valve. -member 56 hasa first recess -9S, f ormed"therein and extending substantially aroundthe outer periphery thereof, the recess 95-being interconnected to the bore 58 of the tab? means and 89 ofthe drive ring 84 cause the valve memberi56 to rotate in unison with' the sleeve 79, the stem 61 rotating inrunison' With the valve member 56 because 1 of the aforementioned frictional drive relation between the stem 61 and valve member'56. V v y Therefore, once the control knob 82 has been axially pushed to'the right to clear the tab means 87 from the slots 88 and has been slightly rotated, the tab means 87 of the drive ring 84' are out of register with the slots 88 of the cover member 72 so that the control knob 82 is held in its pushed in position; and can be'manually rotated to the desired"positionwithout exerting force in opposition to .the forceof the compression spring 92, the tab means 87 .of the drive ring 84 registering with the-slotmean's-88 of the cover member 72 when thecontrol knob is disposed valve member 56 by a pairof spaced bores '96 and 97.

The recess in the valve member-56' is so constructed and arranged, that the sameis disposed in aligned relation'with the inlet 30, of'the valve construction 29 where- V by the'valve member 56 closes off communication between posed cars 74 that are adapted to be secured to the housing 51 by threaded members 75, the cover member 72 portion 76 splined to a split collar 77 by a tab means 78 of the cover 72 e a l 8' a The split collar 77 issplined in any suitable to a generally angular bezel 77a. 7

I having an outwardly directed substantially cylindrical manner A rotatable sleeve 79'is telescopically disposed in the Z cylindrical portion 76 of the cover member 72.. and has a the inlet 38 and the cavity55 when the valve member 56 is in the off position illustrated in FIGURES'Z and 11 and 'is adapted to progressively increase the degree of communication between theinlet-30 and the cavity 55 as the valve member 56- is rotated in the counterclockwise di- "rec tion as illustrated in FIGURES 11-15.

A pair of rotationally aligned

slots

98 and 99 are also formed in the valve member 56 as illustrated in FIG- URE 10, the slots 98. and 99 being respectively interconnected to the'bore 58 of the valve member 56-for a purpose hereinafter described. 1 I V T he housingSl is so constructed and arranged that the same defines a first annular valve'seat 100 in the cavity 55 between the inlet and outlet" 31 and downstream from the valve member 56 previously described, the valve seat 100 encompassing a second and smaller annular valve Seat 101 oifset from the center of the valve seat 100 and disposed in the same plane with the valve seat 100. The valve seat 101 is interrupted by a passage means 102 leading to the exterior of the housing 51 and being interconnected to the pilot burner 28 by a conduit or passage means 103. A bypass passage means 104 is formed in the housing 51 and is interconnected to the controlled pilot passage means 102 and to the cavity 55 of the housing 51 at a point upstream from the valve seats 100 and 101 for a purpose hereinafter described, the bypass passage means 104 being aligned with the

slots

98 and 99 of the valve member 56 whereby the valve member 56 selectively opens and closes the bypass means 104 to the bore in the valve member 56 for a purpose hereinafter described.

A bellows construction 105 is disposed in thecavity of the housing 51 and has one wall 106 thereof interconnected to a retainer 107 secured to the housing 51 by a nut 108, the other wall 109 of the bellows construction 105 carrying a retainer 110 provided with a threaded bore 111.

The interior of the bellows construction 105 is interconnected to a temperature-sensing bulb 112 by a conduit or passage means 113, the bulb 112 being disposed in the "oven '21 and causing the bellows construction 105 toexpand or contract in relation to the temperature of the oven 21 in a manner well known in the art.

A shaft 114 carries a pin 115 at the end 116 thereof, the pin 115 being slidably disposed in a pair of opposed slots 117 formed in the right end of the stem 61 previously described. The other end 118 of the shaft 114 is externally threaded and is disposed in threaded relation with the bore 111 of the retainer 110 of the bellows construction 105.

A bi-metal, spring disc 119 is telescopically disposed 'on the shaft 114 and is retained in a recess 120 thereof,

the bi-metal disc 119 bearing against a valve member 121 s'lidably and rockably disposed on the shaft 114. The valve member 121 is adapted to open and close the valve seats 100 and 101 previously described.

A compression spring 122 has one end 123 thereof engaging a retainer 124 disposed on the retainer 110 of the bellows construction 105 and abutting an annular flange 125 of the retainer 110, the other end 126 of the compression spring 122 bearing against a retainer 127 which is slidably disposed on the shaft 114 and compacts a spacer 128 against the valve member 121.

In this manner, rotational movement of the valve member 56 in a counterclockwise direction causes the shaft 114 to rotate and, through the threaded relation of the end 118 thereof with the retainer 110, causes the shaft 114 to axially advance to the right whereby the bi-metal disc 119 carries the valve member 121 away from the .

valve seats

100 and 101 in opposition to the force of the compression spring 122, the bi-metal disc 119 varying the position of the valve member 121 on the shaft 114 in response to ambient temperature changes.

For example, a setting of 400 degrees'F. by the control knob 82 will position the valve member 121 relative to the seats 100 and 101 a pre-set distance when the oven is at 70 degrees F. and the atmosphere surrounding the bellows construction 105 is 70 degrees F. However, for such a temperature setting of 400 degrees F. for the control knob 82 and the oven at 70 degrees F. and with the atmosphere surrounding the bellows construction dropping to degrees F., the valve member 121 would be at a greater distance from the

seats

100 and 101 because of movement of the wall 105 of the bellows construction 105 to the right in FIGURE 2 because of the drop of ambient temperature surrounding the bellows construction 105 were it not for the bi-metallic disc 119 which compensates for the change in ambient temperature at the bellows construction 105 and changes the shape to be flatter so that the spring 122 moves the valve member 121 back to the left a distance corresponding to movement of the wall 109 of the bellows 105 to the right whereby regardless of the ambient temperature at the bellows construction 105, the valve member 121 will be at the desired distance from the

seats

100 and 101 at any particular setting of the control knob 82 at a particular temperature sensed by the bulb 112 because of the bimetallic disc 119.

When the valve member 121 is moved away from the valve seats 100 and 101 and the valve member 56 interconnects the inlet 30 with the cavity 55 through the recess thereof, fuel from the manifold 23 is adapted to flow out of the valve seat to the passage means 32 leading to the safety valve 33. Similarly, fuel is adapted to flow through the valve seat 101 into the passage means 102 leading to the controlled pilot burner 28 to cause the resulting flame 34 thereof to open the valve member 37 of the safety valve means 33 so that fuel can be supplied to the main oven burner 22.

Since the degree of movement of the valve member 121 away from the valve seats 100 and 101 is related to the temperature setting of the control knob 82 as illus trated in FIGURES l115, the sensing bulb 112 senses the increase in temperature of the oven 21 and causes the bellows construction to expand and move the shaft 114 to the left whereby the valve member 121 moves to left with the shaft 114 toward the valve seats 100 and 101, under the influence of the spring 122 maintaining the valve member 121 against the disc 119, the shaft 114 moving axially relative to the stem 61.

When the temperature of the oven 21 reaches the temperature selected by the control knob 82, the bellows construction 105 has expanded to such a degree that the shaft 114 has moved the valve member 121 to the left against the valve seats 100 and 101 whereby the flow of fuel to the controlled pilot burner 28 is termianted so that the flame 34 ceases to exist and causes the safety valve 33 to close the valve member 37 in the manner previously described. In this manner, no fuel can flow to the main oven burner 22. After the valve member 121 is seated, further expansion of the bellows construction 105 causes the shaft 114 to move to the left relative to the seated valve member 121 to provide overtemperature protection.

When the temperature bulb 112 in the oven 21 senses that the temperature of the oven 21 has fallen below the selected temperature, the bellows construction 105 has collapsed to such a degree that the shaft 114 is'moved to the right so that the disc 119 can again contact the valve member 121 to move the same away from the valve seats 100 and 101 so that fuel can again flow to the pilot burner 28 and through the main passage means 32.

However, it has been found that when the valve member 121 initially opens, suflicient fuel is supplied by' the passage means 102 to the pilot burner 28 to cause the flame 34 thereof to open the valve member 37 of the safety valve means 33 before the valve member 121 supplies sufficient fuel to the passage means 32 to be fully ignited at the main oven burner 22.

Therefore, the valve construction 29vis so constructed and arranged that the valve member 121 supplies sufficient fuel to the passage means 32 to cause ignition at the main oven burner 22 upon the initial opening of the valve means 121 before a sufiicient quantity of fuel is supplied to the pilot burner 28 to cause the flame 34 thereof.

In particular, reference is made to FIGURES 5, 6 and 7 wherein a leaf-type spring 129 has the shank portion 130 frictionally disposed in a bore 131 formed in the housing 51 and disposed olfset relative to the center of the valve member 121 for a purpose hereinafter described, the spring 129 having a reversed turned end portion 132 provided with a cap of epoxy resin 1 33' or the like, which,

will bear. against the valve member 121.

The spring-129 is so constructed and arranged, that a the end 133 thereof normally extends beyond the valve seats 100 and 101 in the manner illustrated in'FIGURE 7 so that when the valve member 121 is being moved to, its closed position, the spring 129 engages the valve merng ber 121 and cocks the sameon the shaft 114 in such a" mannenthat the valve member 121 first seats againstonly a portion of the valve seat7100 as illustrated in FIGURE 7 before the valve member 121is fully" seated against,

the valve seats 100 and ltllin the manner illustrated in FIGURE 2. .r e r V I, V a i V ture, such as between 140 F. and 325 F., the knob 82 is moved to the ,dresired temperature, such as, 170 F., wherebythe, recess 95- of the valve member 56 interconnects the inlet 30"with the bore 58 of the valve member 56 while t'he valvelmemberl56 .closes off the controlled pilot bypass means 104 as illustrated by FIGURES 12 and 13. The rotational. movementof thevalve member 56 to the temperature setting of 170 F...also causes rota,-

tional movement of the shaft 114 in'the above manner whereby the valve member 121 is moved away from the valve seats 1% and 101 to cause fuel to flow to themain passage means 32 and to .the controlled pilot burner28.

Preferably, the spring 129 isdisposed 9O out of phase with the internal valve seat 101. However, it is to be understood that the spring'means 129'c ould be disposed inany desired rotational position relative to the valve seat 101 that would provide the desiredresults of this invention.

Therefore, when the valve member 121 is fully seated again-st the valve seats 100 and 101 and the sensing bulb 112 senses that thetemperature of the .oven 21 is belowr the selected'temperature, the bellows-construction 105 100 and 101.

' However, since the spring ,129 is offset relative to the center of the valve member .121, the spring me'ans -129.

causes the valve member 121 tobegin to cock on the shaft '114 so-that a portion of the valve seat 100isthe first to open at a. po-intspaced from the valvese'at 101 as illustrated in FIGURE 7. p V I In this manner, sufficient fuel flows out of the partially As long as the: valve member 121 is open, a flame 34 valve'seats'. 100 ;and 101 toi terminate the supply of fuel to'the controlled pilot burner 28'wher'eby the flame 34 r 7 ceases to exist and the safety valve means 33 closes to prebegins to collapse to move-the shaft 114,"and thus, the a valve member 121 to the right. away'from the valveseats 7 opened valveseat 100 to the pas'sagemeans'32 to pro! I vide 'a proper amount of fuel for ignition at the main ove'n burner 22 before a suflicierit amount of fuel is allowed to pass through the valve seat 101 to cause a'fiarne 34 at the controlled pilot burner 28.

Thus, each time the valve member 121 jopens, a sufficientamount of fuelis present at the safety valve 33' to cause ignition at the main. oven'burner 22 when a flame 34 appears at the controlled pilot burner- 28 which 7 opens the safety valve 33.- V Y j V The operation ofthe fuel control system20 of this invention will now be described. v When the control system 20 of this invention has been initially installed, the height of the flame 34 of the controlled pilot burner 28 can be regulated in the following manner. V As illustrated in FIGURE 12, the, control knob 82 is rotated to the dot 134 by first; depressing the knob 82 T to clear the locking tab means 87 of the drivering 84 from the slots 88 of "the cover member 72' inrthe manner previously described.

Whenthe control knob' 82 is rotated to the dot i134 illustrated in FIGURE 12, the valve member. 56 is rotated in the manner illustratedjin FIGURE l2,'whereby the recess 9 5,o-f the valve member 56 interconnects. the

inlet withthe bore 58' thereof and interconnectsthe bore 58 with the bypass 'meansj104 by the recess 98 so that fuel can be supplied to the controlled pilot'burner' 28"independently'of the position of' the vvalve member "described.

vent fuel to flow to the main ovenburner 22.

I Subsequently, when the temperature. of the oven 21 has fallen below the selected temperature, thebellows 105 has eollapsed to such a degree that the. shaftf114moves to the ,right and moves thevalve member 121 'away-from'the valve seats-100 and 101 topermitaflame- 34 to exist at the controlled pilot burner 28 and open the valve means 33aso that fuel will flow to the mainoven burner 22 to be ignited and heat the oven21. J

Thus, the valve member 121 cycles between the opened and closed positions thereof in response to the temperature of'the oven 21 to' turn on andolfthernain oven burn- 7 er 22 so thatthetemperature ;of the oven 21 is maintained at the selectedlow temperature, the valve member121 'when'moving from the 'close'd'p'os'i-tion to the open position thereof always assuring thatZa sufficient amount offuelis suppliedby the passage means 3210 be ignited at "the main oven burner-22 when the flame 34 appears at the'control pilot burner 28 in the manner previously Therefore; it Ican beseen tlrat the .fuel'control system 20 ofthis invention'is readilyadapted to maintain the temperature'of the oven 21 at a low warming and nonc-ooking temperature while still only utilizing the main oven'burner' 22 of the oven 21. t

Should it bedesired-to utilize the oven 21 ata conventional cooking temperature, such as between325 F. and

'550 'F., the control knob 82 is rotated in a counterclockwise direction tothe selected temperature, such as 500 'F. as illustrated in FIGURE 14. Withrthe control knob '82-disposed in the position illustrated in FIGURE 14, not only does'the valve member '56 interconnect the inlet 30 with the bore 58thereof by the recess 95, but the valve member, 56 also interconnects the bore 58.015 the valve member 56 Withjthe controlled pilot bypass passage .rne ans;104 by the recess 9930111211 :the flame ,34 will always-appeartat the :controlled pilot burner 28' when'the'ternperature setting of the oven'21 is between 325 F. and 550 F. in the embodiment of the 121, the fuel issuing from the controlledpilotburner '28 being ignited by the standby pilot burner 24.

Should the flame 34 at the controlled pilot burner 28 need adjustment, an adjusting memberrl3 5, FIGURE 2,

is rotated in the proper direction to'cause the passage means 102 in the'housing 51 to supply a sufiicient amount of fuel to the controlled pilot burner 28 to provide the ,theoven 21, at a'low warming and non-cooking'temperaa control system 20 illustrated in the drawing regardless of the position of the thermostatically controlled valve member 121. V V

Thus,iat this high temperature setting, the safety. valve 33 is always. opened because a flarnef34 always appears at' the controlled pilotburner 28 whereby the valve 121 merely throttles the'rflow of fuel to the main oven burner 22 in response to thetemperature of the oven 21.

Therefore, it can be seen that the fuel control system 20 of this invention is notonlyradaptcd to maintainan oven 'or the like at a relatively low warming and noncooking tenrperature'with a single main oven burner, but

is also adaptedito maintain theo-ven at a selected high 9 cooking temperature utilizing the same main oven burner, features heretofore unknown in fuel control systems for domestic gas-fired range ovens and the like,

When the fuel control system is first incorporated in an oven or the like, calibration of the thermostatic control device is a simple operation and is accomplished by placing the temperature sensing bulb 112 in a bath having a pre-determined temperature, for example 400 F.

The control knob 82 is rotated counterclockwise to the 400 F. mark on the dial thereof.

With the insert 83 removed from the control knob 82, a screw driver or the like is inserted through the control knob 82 and is engaged in the bifurcated end 136 of the stem 61. The adjusting stem 61 is axially pushed to the right to thereby release the rotational drive between the valve member 56 and the stem 61 so that the adjusting stem 61' can be rotated in either a clockwise or counterclockwise direction independently of the valve 56 to cause the valve member 121 to be disposed in light contact with the valve seat 100.

Without any further rotation, the screw driver is released from the adjusting stem 61 to thereby cause the adjusting stem 61 and valve member 56 to be again placed in rotational drive whereby the control is accurately calibrated.

If the thermostatic control device of this invention is installed on a range, calibration thereof is easily accomplished by removing the insert 83 from the control knob 82. Thereafter, a suitable thermometer is placed in the center of the oven 21 and the control knob 82 is rotated counterclockwise to a predetermined temperature, for example 400 F. The control system is then allowed sufficient time to level out and the oven temperature on the thermometer is noticed. Thereafter, a screw driver is then inserted through the control knob 82 and operatively engaged in the bifurcated end 13 6 of the adjusting stem 61. With the screw driver so engaged, the adjusting stem 61 is depressed to the right out of its rotational drive with the valve member 56. Subsequently, with the screw driver held so as to prevent rotation of the adjusting stem 61, the control knob 82 is rotated clockwise or counterclockwise to the temperature setting indicated by the thermometer disposed in the oven 21. The screw driver is then disengaged from the adjusting stem 61 in a non-rotational manner whereby the insert 83 can be replaced in the control knob 82 to complete the calibration procedure.

Another calibration can \be accomplished by the valve construction 29 after the fuel control system 20 has been installed on a range or the like.

In particular, a suitable thermometer is placed in the center of the oven 21 and the control knob 82 is rotated counterclockwise to a predetermined temperature, for example, 400 F. The control system is then allowed sufficient time to level out and the oven temperature on the thermometer is noticed. If there is mis-calibration, the control knob 82 and sleeve 79 are removed as a unit from the valve construction 29.

Noting the position of the reference indicium 137 on a plate 138 carried at the end of the adjusting stem 61, a screw driver is engaged in the bifurcated end 136 of the adjusting stem 61 to depress the stem 61 and disengage rotational drive between the stem 61 and valve member 56. The adjusting stem 6-1 is then rotated clockwise or counterclockwise, as the case may be, an angular distance corresponding to the noted number of degrees of mis-calibration. For example, if each graduation 139 on the end of the valve member 56 is designed to represent 25 F. temperature variation and the noted mis-calibration is also 25 F., the adjusting stem 61 is rotated an angular distance of one fixed graduation 139 in relation to the reference indicium 137 of the plate 1-38. The screw driver is then disengaged in a non-rotational manner and the control knob 82 and sleeve 79 are replaced to complete the calibration procedure Therefore, it can be seen that an improved valve construction 29 is provided by this invention which not only readily performs the desired functions for the fuel control system 20 of this invention, but which is also adapted to readily adjust the calibration thereof so that an accurate control is provided.

The valve construction 29 can be modified in the manner illustrated in FIGURE 2A to provide a non-cycling oven control, if desired.

In particular, the valve member 121a of the valve construction 29a is provided with a recess 140 in the region of the 'valve seat 101A whereby the cavity 55a of the valve construction 2% is always in communication with the passage means 102a thereof, regardless of whether the valve member 1211a. is fully seated against the valve seat a as illustrated in FIGURE 2A.

In this manner, fuel is continuously supplied to the controlled pilot burner 28 so that the resulting continuous flame 34 thereof keeps the valve means 33 in an open position when the control knob 82 is in an on position thereof, regardless of the position of the thermostatically controlled valve member 12 1a.

When it is desired to utilize the main oven burner 22 for broiling, the control knob 82 is rotated to the position illustrated in FIGURE 15 whereby the valve member 56 continues to interconnect the inlet 30 with the bore 58 of the valve member and closes off communication between the bore 58 and the controlled pilot bypass means 104.

However, it has been found that when the valve member 56 is rotated to the broil position thereof, the shaft 114 has moved the valve member 121 away from the valve seats 100 and 101 such a distance that the valve member 121 will not close against the valve seats 100 and 101 during the broiling operation of the oven 21.

Therefore, fuel is continuously supplied to the controlled pilot burner 28 by the opened valve seat 101 during the broil setting of the control knob 82 whereby the flame 34 of the controlled pilot burner maintains the valve means 33 in the opened position so that fuel passing through the continuously opened valve seat 100 can be continuously supplied to the main oven burner 22 for broiling purposes.

While the form of the invention now preferred has been disclosed as required by the statutes, other forms may be used, all coming within the scope of the claims which follow.

What is claimed is:

1. In combination, a main burner, a source of fuel, main passage means interconnecting said source of fuel to said main burner, a pilot burner, ignition means for said burners, a first valve means in said main passage means for controlling the flow of fuel to said main burner, means responsive to a flame at said pilot burner to open said first valve means, a valve construction in said main passage means upstream from said first valve means, said valve construction having a first valve seat for interconnecting said source of fuel to said first valve means and having a second valve seat inside said first valve seat for interconnecting said source of fuel to passage means leading to said pilot burner, a valve member carried by said housing for opening and closing said valve seats, spring means carried by said housing and extending beyond said valve seats to engage said valve member before said valve member seats against said valve seats, said spring means being offset relative to the center of said valve member to cause said valve member to cock as it nears said second valve seat and to initially engage only a portion of said second valve seat before it completely closes said valve seats so that sufficient fuel is adapted to be supplied to said main burner to have full ignition thereof before a flame appears at said pilot burner.

2. In combination, a housing having a valve seat, a valve member carried by said housing for opening and valve seat and to said first valve seat.

controls movement of said valve member I it closing said valve seat, and spring means carried by said housing and tending to extend-beyond said valve seat 'to, engage said valve member before'said valve member seats against said valve seat, saidrspringgmeans being 'oifset relative to the center of said valve'member to I, cause said valve member'to cock only as it nears said valve seat and to initially engage only a portion of said valve seat before it completelyseals closed said valveseat.

3.. In combination, a housing having a first valve seat;

and having a second valve seat encompassing said first valve seat, a valve member carried by said housing for opening and closing said .valve seats, and spring means.

carried by said housing and tending to extend beyond said valve seats to engage said valve member before said valve member seats againstsaid valve seats, said. spring] means being oifset relative. to the center of saidvalve said second valve seat and to initially engage only a portion of'said second valve seat before it completely seals closed said valve seats.

valve seats are disposed in the same plane.

5. A combination as set forth in claim '3 'wherein said second valve seat is substantially annular and said first valve seat is substantially annular. and is oifset relative to the center of said second valve seat, and wherein said spring means is offset relative to the center of s aid second 6. A'c'ombination as set' forth' in claim 3 wherein tem perature responsive meansis carried by said housing and relative to said valve seats.

a temperature responsive V .valve member relative'to said valve seats.

of fuel, main passage means interconnecting said source of fuel to saidmain burner, a pilot burner, ignition means for said burners,-a first valve means in said main passage means for controlling the flow of fuel to said main burner,

' meansresponsive to a flame at said pilot'burner to open said first valve means, a valve construction in said main passage means upstreamfrom said first valve means, said valve construction having a firstvalve seat for in- 'terconnectingsaid source of fuel'to said first valve means member to canse'saidvalve member to cock as it :nearsr 20 4. A combination as set'forth in claim 3 whereinsaid said second valve seat is disposed inside said first valve 7. In a fuel control system, .a valve construction having a first valve seat and a second valve seat for respectively interconnecting a source of fuel to difierent burner means, a valve member for opening and closing said valve seats, and means for moving and initially tilting said valve I 7 wherein A and havinga second valve seat for interconnecting said sourceof 'fuel'to passage means leading to said pilot burner, a valve member for opening and closing said valve seats, and means formoving and initially tilting said'valve member relative to said seats to initially open said first valve seat to permit suificient fuel to. flow to said mainlburner to have full ignition thereof before said second valve seat-is opened sufliciently to permit ignition at its respective burner means.

12. A'fuel control system according to claim 11 wherein seat. I I

13. A fuel control system according to claim 11 wherein said valve seats are inv the same plane.

14. A fuel control system according to claim 11 where- "in temperature responsive means controls movement of said valve member relative to said valve seats.

References: Cited in the file of this patent v -UNITED STATES PATENTS 'Bell et a1; July 7, 1891 1,576,086 Browne Mar. 9, 1926 1,704,807 ONeal Mar. 12, 1929 1,705,787 I Shuell et a1. n Mar. 19, 1929. 1,842,335 f Te Pas a Jan. 19, 1932 1,950,120 McKee 'Mar. 6, 1934 2,069,069 Horton Jan. 26, 1937 2,106,929 McClure Feb. 1, 1938 f 2,505,455 Andersson Apr. 25,1950 2,509,679 Evans May 30,1950 2,898,048 Stucka Aug. 4, 1959 2,994,755 r Hildenbrandt et a1. Aug. 1, 1961 3,065,913 Holzboog et a1 NOV. 27, '1962 FOREIGN PATENTS France May 15,,

Claims

1. IN COMBINATION, A MAIN BURNER, A SOURCE OF FUEL, MAIN PASSAGE MEANS INTERCONNECTING SAID SOURCE OF FUEL TO SAID MAIN BURNER, A PILOT BURNER, IGNITION MEANS FOR SAID BURNERS, A FIRST VALVE MEANS IN SAID MAIN PASSAGE MEANS FOR CONTROLLING THE FLOW OF FUEL TO SAID MAIN BURNER, MEANS RESPONSIVE TO A FLAME AT SAID PILOT BURNER TO OPEN SAID FIRST VALVE MEANS, A VALVE CONSTRUCTION IN SAID MAIN PASSAGE MEANS UPSTREAM FROM SAID FIRST VALVE MEANS, SAID VALVE CONSTRUCTION HAVING A FIRST VALVE SEAT FOR INTERCONNECTING SAID SOURCE OF FUEL TO SAID FIRST VALVE MEANS AND HAVING A SECOND VALVE SEAT INSIDE SAID FIRST VALVE MEANS FOR INTERCONNECTING SAID SOURCE OF FUEL TO PASSAGE MEANS LEADING TO SAID PILOT BURNER, A VALVE MEMBER CARRIED BY SAID HOUSING FOR OPENING AND CLOSING SAID VALVE SEATS, SPRING MEANS CARRIED BY SAID HOUSING AND EXTENDING BEYOND SAID VALVE SEATS TO ENGAGE SAID VALVE MEMBER BEFORE SAID VALVE MEMBER SEATS AGAINST SAID VALVE SEATS, SAID SPRING MEANS BEING OFFSET RELATIVE TO THE CENTER OF SAID VALVE MEMBER TO CAUSE SAID VALVE MEMBER TO COCK