US2637385A

US2637385A - Automatic ignition and control mechanism for oven burners

Info

Publication number: US2637385A
Application number: US260901A
Authority: US
Inventors: Charles M Mayer
Original assignee: TAPPAN STOVE CO
Current assignee: TAPPAN STOVE Co
Priority date: 1951-12-10
Filing date: 1951-12-10
Publication date: 1953-05-05
Anticipated expiration: 1970-05-05

Description

May 5, 1953v c. M. MAYER AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS 4 Sheets-Sheet 1 Filed D90. 10, 1951 rllllllilllill.

r 6% Qm M M. w a: MNW v n e q b3 P3 Q N\\ am I N U *Q :m A w ms mm 6 c. M. MAYER 2,637,385 AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 10, 1951 4 Sheets-Sheet 2 36 4 A 56 52 ,5 r9 60 W4? l 27 1 I. \\\\|L\ 5 1, a? as W 4745' 6 68 j 69 5 IZj/f z WW k h a g BY or es yer M y 1953 c. M. MAYER 2,637,385

AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 10, 1951 4 Sheets-Sheet s I m I Q k \9 (War/es Af/Vayer Y 5, 1953 c. M. MAYER 2,637,385

AUTOMATIC IGNITION AND CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 10, 1951 4 Sheets-Sheet 4 N INV Char/es N1 M0 yer Patented May 5, 1953 UNITED STATES PATENT OFFICE AUTOMATIC IGNITION AND CDNTBOL MECHANISM FOR OVEN BURNER Charles M. Mayer, Mansfield, Ohio, assignor to The Tappan Stove Company, Mansfield, Ohio, a corporation of Ohio Application December 10, 1951, Serial No. 260,901

13 Claims. 1

This invention relates to an automatic electric ignition and control mechanism for cooking range burners using gaseous fuel and is a modification of the control mechanisms shown in the co-pendins application of Charles M. Mayer Serial No. 200,203, filed December 11, 1950, now Patent No. 2,584,147, and the co-pending application of Charles M. Mayer and John M. Hoff Serial No. 153,664, filed April 3, 1950, now Patent No. 2,577,787. It is specifically designed and adapted for automatically igniting and controlling the operation of oven burners in cooking ranges, and may be used in conjunction with a time control mechanism or independently thereof as desired.

The mechanism is designed for use with a main gaseous fuel burner which is adapted to be ignited by a gaseous fuel pilot burner. As long as the pilot burner is ignited it is immaterial whether or not the main burner burns constantly. It may be extinguished for some reason, but it will be promptly re-ignited by the pilot burner if fuel is supplied thereto. But if the pilot burner is extinguished for any reason while the main control valve is still open to supply gas to the main burner a very dangerous situation sometimes arises. Let us assume that both the pilot burner and the main burner are extinguished during operation for some reason. Gas can then flow to the main burner but since the pilot burner is extinguished. the main burner will not be ignited and unburned gas will accumulate in the oven which may violently explode when an attempt is made to ignite either the main or pilot burner. It has been found by experience that both the pilot burner and the main burner are frequently extinguished during use while the main control valve is open to supply gas to the main burner. This is sometimes due to a momentary failure of the gas supply or the slamming of the oven door, or to various other reasons.

In order to prevent any accumulation of unburned gas and thus eliminate any danger of an explosion therefrom in the event the pilot burner is extinguished. for any reason while the control valve is still set to supply gas to the main burner, I provide in my improved apparatus safety control mechanism by which the supply of gas to both the main burner and the pilot burner is completel out off, independently of the main control valve, in the event the pilot burner is extinguished for any reason while the main gas control valve is open.

My improved apparatus includes a main gaseous fuel burner by which the oven in a cooking range is heated. The main burner is adapted 2 to be ignited by a aseous fuel pilot burner which burns only during the time the oven is in operation. At other times the supply or" gas to both the main burner and the pilot burner is cut on by a main control valve which is interposed in a conduit between the gas supply manifold and the burners, and has two open positions and one closed position. In one open position the mechanism is set for manual control and in the other open position the mechanism is set for automatic control by the time control mechanism. When the main control valve is open gas will flow from the manifold through the main control valve and into a safety control valve mechanism. From the safety control valve mechanism gas will flow through a small branch conduit directly to the pilot burner; and through the main conduit and a standard thermostatically operated oven temperature control valve to the main burner. A normally open master control switch which is operatively associated with the main control valve is arranged to be closed by the opening of the main control valve and to be opened by the closing of the main control valve. The closing of the master control switch, as the main control valve is opened to supply gas to the burners, energizes through a normally closed thermostatically operated switch an electric resistance ignition element and a solenoid which is operatively connected to the safety control valve mechanism. The energization of the solenoid causes it to operate the safety control valve mechanism to permit the flow of gas to the pilot burner while cutting off the supply of gas to the main burner. The pilot burner is ignited by the electric ignition element and projects a flame against a thermostatic element, which controls the operation of the normally closed switch, and against a thermocouple which is operatlvely connected. to the safety control valve mechanism. After the thermostatic element becomes heated it opens the normally closed switch which de-energizes the electric ignition element and the solenoid. As soon as the solenoid is (lo-energized the safety control mechanism is automatically operated by spring means to supply gas to the main burner through the oven temperature control valve. The main burner is then ignited by the pilot burner. The thermocouple, as long as it is heated by the pilot burner, maintains the safet control valve mechanism in condition to supply gas to both the main burner and the pilot burner. The oven temperature control valve then regulates the supply of gas to the main burner so as to maintain the desired oven temperature. As long as the pilot burner is ignited the main burner will burn normally under the control of the oven temperature control valve until the main control valve is manually turned ofi. But if during operation the pilot burner is extinguished for any reason the thermocouple will immediately cool and allow the safety control valve mechanism to automatically cut off the supply of gas to both the main burner and the pilot burner. As an example of the manner of operation of the apparatus, let us assume that during operation the pilot burner is suddenly extinguished, for instance, by a momentary failure of the gas supply from the manifold to the burners. The thermocouple immediately cools, allowing the safety control valve mechanism to cut off communication between the manifold and both the main burner and the pilot burner. The main control valve is still open and the master switch closed. Then after the thermostatic element has cooled, closing the normally closed switch, which is maintained open by the thermostatic element during normal operation of the oven, the electric ignition element and the solenoid are again energized. The energization of the solenoid will cause it to operate the safety control valve mechanism to establish communication between the manifold and the pilot burner only. Then when gas is again available the pilot burner will be ignited and re-establish normal operation of the oven as previously described. In the event of a power failure during normal operation of the oven under manual control, the main burner will continue to operate normally under the control of the oven temperature regulator valve until the burner is turned on by the main control valve, assuming of course that the pilot burner continues to burn. In the event of a power failure before gas is turned on by the main control valve, the pilot burner can be manually ignited as will be hereinafter explained. The supply of gas to both the main burner and the pilot burner will then be controlled by the pilot burner through the thermocouple and safety J 1 tion will be apparent from the following specificontrol valve mechanism as previously described.

In order to adapt the mechanism for automatic control by a standard electrically operated time control mechanism I provide a bypass conduit around a portion of the main conduit between the manifold and the safety control valve mechanism with the main control valve located at a junction of the bypass conduit and the main conduit so that when it is in one open posiiton it will direct fuel straight through the main conduit for manual control and when it is in the other open position it will direct fuel through the bypass conduit for automatic control. I also interpose a normally closed solenoidoperated valve in the bypass conduit, and I provide a supplemental master switch which is adapted to be closed by the setting of the main control valve for automatic operation and to be opened by the closing of the main control valve. The supplemental master switch is in series with the normally closed thermostatically operated switch and a normally open switch which is adapted to be opened and closed by the time control mechanism at predetermined set times. The solenoid which actuates the normally closed valve in the bypass conduit is also in series with the time control actuated switch. For automatic operation the time control mechanism is set to close the associated switch. at a predetermined time and to open it at a predetermined later time, and the main control valve is set to direct fuel through the bypass which closes the supplemental master switch. Then at the set time the time control mechanism will close the associated switch which will effect energization of the electric ignition element, the solenoid for actuating the time control mechanism and the solenoid for opening the normally closed valve in the bypass conduit. Fuel will then flow to the safety control valve mechanism and from there to the pilot burner where it is ignited by the electric ignition element. The mechanism will then function as previously described under control of the safety control valve mechanism and the oven temperature control valve until the time control mechanism opens the associated switch which effects closing of the normally closed valve in the bypass conduit thus cutting oif the supply of fuel to both the main burner and the pilot burner.

The principal object of the invention is to provide an improved electrical ignition and automatic control system for cooking range oven burners using gaseous fuel.

Another object of the invention is to provide in an electrical ignition and control system of the character described improved means for completely shutting off the supply of gas to both the main burner and the pilot burner in the event the pilot burner becomes extinguished for any reason before the supply of gas to both the main burner and the pilot burner is cut off by the main control valve.

Another object of the invention is to provide an apparatus of the character described which is so constructed and arranged that food in an oven will be cooked the set length of time regardless of temporary current failure during operation.

Still another object of the invention is to provide an improved electrical ignition and control system of the character described which may be used in conjunction with a time control mechanism or independently thereof as desired.

Other and more limited objects of the invencation and the accompanying drawing forming a part thereof, wherein:

Fig. 1 is a diagrammatic view illustrating my improved electrical ignition and safety control mechanism as applied to a cooking range oven burner using gaseous fuel;

Fig. 2 is an enlarged central longitudinal ver tical section through the safety control valve mechanism showing the various parts in the position they assume when the oven burner is turned off Fig. 3 is a view similar to Fig. 2 showing the various parts in the positions they are automatically moved to when the main control valve is first turned on to initiate the operation of the main oven burner;

Fig. 4 is a horizontal section taken on the line 4-4 of Fig. 1;

Fig. 5 is a sectional view through the main control valve showing it in position to direct fuel straight through the main conduit;

Fig. 6 is a view similar to Fig. 5 showing the main control valve set to direct fuel through the by-pass conduit;

Fig. '7 is a view similar to Fig. 1 showing a slightly modified form of the invention; and

Fig. 8 is a view similar to Fig. 1 showing another modified form of the invention.

Referring now to the drawing by reference aee'rsse ehareeter he numeral imitates a aseous fuel bu or which mounted; or heat'ns relation tea c o i era-nee even 3, Gase us fue uppl d; to the I from a mani old M t er ash a who it 3 interposed in theeen uit ere-a. control; valve aseietv control valv meehaniern. generally indicated. by:- the numeral 5 e e. e cont olvelve. Th st n ee trol v lve tie a eut offvalve of taa larcl construc ion avi g two. OBQIFI; hositiohs and. on closed p sit et which whe in an penoron posi ion nermlts the flow of as from the maniold to the burner I. and in clos d or off p siti cu s off fl w or s e t the burner This valve is manual y opened and closed by a suitable h dle and a-valve stem and direct y e htrols t or tien oi he entire apparatus in that i What r the eneratien of the entire apparatus hen t s urned. to n en p sition and termia s t operat n when it is turned to he on po it on, the entrol valv 4. as, flows through h ndu t 3 to the safety control valv m han m 5 to. be deeeribecl n detail herein: af r, rom the af ty c n ol velv mechan m 5 the s e flo s hroug t e onduit: 3 and the oven temperature control valve ii to the, burner t. The oven temperature control valve 6 is on erative to regulate the amount of gas flowing to the burner I in order to maintain, the oven desired set temperature The valve ii is set to, any desired temperature by a handle it having a pointer 12 which cooperates with a graclu atecl dial i3 carried by the valve E5. The valve 6 is controlled according to the temperature set ting by a thermostatic element, iii which is mounted in the oven 2 and is: connected to the valve 6 as shown at [5. The oven temperature control valve 6 is oi standard well known Q0111? struetion, Con q n ly it s n shown in tail herein There are many difierent construe l t me av ila l any on of whi h will work equally Well. h ein- Gas s a o suppl e o e pilot. bu er t hrou h a breach. conduit I? which extends be ween th sa ety ontr valv mechanism the pilot burner i Th Pil burn r 15 isnosed adjacent the rear end of the main burner in in posit on toisn t he burner I wh as s upplied thereto- An ele c l; ition el ment {8. is operatively associated with the pilot burner H5 in. position to ignite the pilot; burner it when, gas is sup lied thereto. A thermo a c element It, and a th o oupl 29 a e re ruited in po it n, to be h ate by a fl m from the pilot burner, The thermostatic element it is operativ t o n n lose a switch 2-H whi h. c ntrols the energizatlon of the eleotri a l ignition elemeht it nd a solen id 22 W hh n, ener ized r" erat s he afe y control valve. me h nsm to n ply gas to the nilot. burner i t as will he. described in connection with the description oi; the. safety control valve mechanism and. the operation the Whole apparatus. The thermocouple 2% when located is operative to. hole; thev safety control valve mechanism in condition. to maintain the supply of gas to both the pilot burner it and the main burner i as will also be described in connection with the description of the safety contrcl valve mechanism and the operation of the apparatus. A master control switch. 23 which is associated with the main control valve l adapted to be opened and closed simultaneouslyvzith the closing and opening, of the. main control valve l. As the control valve 4 is turned ir m th ff o losed, p tion t one on or ope position h swi ch mechanism 33 is moved fr m the open. position to the closed position by ore ratins lev r M w ieh co perates w th cam sect on 2 on. the ma n control. alve stem 8- Conv r e v, wh n the main. contr l, valve 5, is turn d, irom the ouen on. pos on to the. close or e i o sitien, the switeh meet em i is moved from. th closed p sition to the open to; ota An e ectric: circuit betw en the h moc unle. t9 and the s fety control. valve thee sm e is established. ya copper tube 26 whi h. nc os s an insulated. wire Zl- Th ons ruct on. o he safety o trol valv m chanism 5. and it con ct on to. the so noid 22 l new b e ed e erence is ins had to Fig e of the; crawle mecha ism comp se a asine havin a ehemher tit in one earl th of and a chamber 3-1- in. the other th reet. The hambers 36- nd, 31- are conheet y a c re 38: of educes d ameter- A val s at 5. is located atone the here i and. similar v lve a t is lo at th o her en of th h re lit. chamber t i closed by a re. movable an it onelthe t7 is closed by a removable c n t A. sleeve it, havin emi walls and. es, is carried bv the can ti and x ends into the chamber 38. valve stem at which is el oahly moun ed in a. bushing. carried by the end wall of the sleeve 53, extends from the chamber 35 into the sleeve is A valve disc 58 of suitable,- material is secured to one end of the valve stem within the chamber 36, and a metal disc secured to the other end of the stem it Within the sleeve 453. A spring {ill disposed about the valve stem to between the valve disc 13 anrl the end wall of: the sleeve :13, normally holds the valve disc ti} against the valve seat A 1e s shoe magnet 5. is secured to one end of a h llow steriorlv threaded stud 52 which x tend ou thro h, a i ned pe ture in the en Wall a l, of the sleeve 23, and in the end of the cap ii. A nut 53 screwed onto the outer portion of the stud 5 S urely holds the 5i and the sleeve 43 in place. The legs of the magnet 55 have a winding 5% thereon one, end of which is connected. to the tube 2.5 and the other cool of which is connected to the ire 2,? in the tube 26-. he tube 26 is inserted into the hollow stud 5i? n is h d in pi ce. by a screwfittins 52 A sleeve 55, is screwed into a, threaded recess in the end of the cap it, as indicated at 55, and extends into the. chamber 3'! a slight distance. Qne end of the sleeve to is closed by an end. wall iii, and the other end which is. open registers with a. circular aperture 55?. in the end Wall of the cap t2. A plug 5.9 is slidahly mounted in the sleeve 55 and extends out through the aperture 5% in the cap 52. The outer enrl of the plug 5'9 has a reduced extension to formed integral therewith, providing an annular shoulder til around the extension 63 at the outer end. of the plug a stem 62- which is secured to the inner end of the plug 5% extends out through aperture 63, in the end Wall E? of the sleeve 55, and through the chamber 3'! and; into the bore The stem 62 has a collar 8 rigidly secured there- 7 the valve disc 65 against the collar 64. A compression spring 61 which is stronger than the spring 66 is disposed about the stem 62 within the sleeve 55 between the inner face of the end wall 51 and the inner end of the plug 59. The spring 6'! is operative to return the plug 59, stem 62 and valve disc 65 from the position shown in Fig. 3 back to their normal position as shown in Fig. 2, against the resistance of the spring 66. A port 68 in the casing 35 provides communication between the chamber 36 and the conduit 3 to allow gas to flow from the main control valve 4 into the chamber 36. During normal operation of the main burner I gas flows from the chamber 36 through the reduced intermediate bore 38 and into the chamber 31. A port 69 which establishes communication between the conduit I I and the bore 38 is provided to supply gas to the pilot burner I6; and a port Iii establishes communication between the chamber 31 and the connector ID to permit the flow of gas from the chamber 3'! to the main burner I through the oven temperature control valve and the conduit 3.

The safety control valve mechanism is operatively connected to the solenoid 22 by a yoke l2 and a link 73. The yoke I2 which encompasses the safety control valve mechanism 5 as shown in Fig. 4 comprises a pair of spaced parallel arms I4 which are connected together at one end by a bridge I5. therein through which the reduced end 80 of the plug 59 extends with the inner face of the bridge engaging the shoulder BI between the plug 59 and the reduced extension 66 thereof. The other ends of the arms I4 terminate in a pair of spaced parallel cars 71 to and between which one end of the link I3 is pivotally connected. The other end of the link "I3 is pivotally connected to the movable core "I8 of the solenoid 22 as indicated at 19.

In order to adapt the mechanism for automatic control by a time control mechanism 96 I provide a by-pass conduit iIlI around a portion of the conduit 3 between the manifold M and the safety control valve mechanism 5 and I cate the main control valve 4 at a junction of the main conduit 3 and the by-pass HJI so that in one open position of the valve l fuel will be directed straight through the conduit 3 and in the other open position thereof fuel will be directed to the by-pass conduit It! In the by-pass IIii I interpose a normally closed solenoid valve I02 which is adapted to be opened and maintained open by a solenoid I03 when the solenoid I63 is energized. I also provide a supplemental master 4 control switch 295 which is also associated with the main control valve i and is adapted to be closed by the setting of the main control valve in position to direct fuel through the by-pass conduit NH and to be opened when the main control valve is turned to oil position. The switch I94 is actuated by the cam on the main control valve stem 8 and a link Iii-5. The time control mechanism 90 is of standard construction and comprises a self-starting electric clock 9|, a normally open switch 92 and mechanism responsive to the clock 9| and operative to close the switch 92 at a predetermined set time and to reopen the switch 92 at a predetermined set later time. Operating current is constantly supplied to the clock 9| through the

leads

93 and 94. The time control mechanism is set as desired by the

buttons

95, 96 and 91. The button 95 is provided to set the time at which it is desired to initiate operation of the burner I; the button 96 is pro- The bridge I5 has an aperture It? :3

vided to set the time at which it is desired to terminate operation of the burner I, and the button 91 is provided to set the time control mechanism in operative condition. After each automatic operation the time control mechanism automatically returns to its normal inoperative condition and must be reset for each subsequent automatic operation of the burner I. The time control switch 92 is disposed in series with the supplemental master switch I04 and with the normally closed thermostatic switch 2!. The time control switch is also disposed in series with the solenoid I03 which actuates the valve I02.

The operation of the apparatus will now be described in connection with Fig. 1 which includes a wiring diagram showing the electrical circuits of my improved ignition and control apparatus with a time control mechanism incorporated therein. To initiate the operation of the oven burner I under manual control it is only necessary to set the oven temperature control valve 6 to the desired temperature and to manually turn the main control valve 4 from the old position to the on position, shown in Fig. 5, which directs the fuel straight through the conduit 3 from the manifold M to the safety control valve mechanism 5. After 1% the ignition and operation of the burner are automatically controlled until the operation of the burner is terminated by manually turning the main control valve 4 from the on position to the oil position. As the main control valve f: is turned from the Oh position to the on position the master switch 23 is simultaneously closed by the cam 25 and lever 24. After the main control valve has been opened gas can flow from the manifold through the main control valve and into the chamber 33 of the safety control valve mechanism 5, the various parts of which are in the position shown in Fig. 2. But the gas can go no farther since the valve disc 118 is being held against the valve seat 39 by the spring 50, thus closing the only exit from the chamber 355. As soon as the switch 23 is closed current flows from one side I It. of the line through the lead I I I to the switch 23 and thence through the lead I I2 to the switch 2 i. From the switch 2| the current fiows through the lead II 3 to the electrical resistance ignition element i8, thence through the ignition element It and back to the other side I I4 of the line through the lead I I5, thus completing a circuit through the ignition element I 8 which energizes it and renders it operable to ignite the pilot burner it as soon as gas is supplied thereto. From the normally closed switch 2! the current also flows through the leads H3 and lit to the solenoid 22, thence through the winding of the solenoid and back to the other side II 4 of the line through the leads I Il and I l5, thus complet ing a circuit which energizes the sol noid 22. The energization of the solenoid 22 causes it. through the link 73 and yoke 72, to shift the various parts of the safety control valve mechanism from the position shown in Fig. 2 to the position shown in Fig. 3. In this position the valve disc 58 is held away from the valve seat 39 and the metal disc is is held against the ends of the logs of the magnet all by stern $2 acting against the resistance of the spring This allows gas to flow from the chamber 35 into the bore 38 and thence through the port 59 and conduit Il' to the pilot burner I5 where it is ignited by the ignition element I 8. But the gas cannot yet flow to the main burner I since the valve disc 65 is being held against the seat 41'] by the spring 66 which cuts off communication between the bore 3i? and the chamber 3i. As soon as the pilot burner I6 is ignited it projects a flame against and heats both the thermocouple 2B and the thermostatic element is. The heating of the thermocouple 26 generates a minute current which energizes the magnet 51 sufficiently for it to hold the metal disc 49 and the stem 45 and valve disc S8 secured thereto in the position shown in Fig. 3 against the pressure of the spring 59 after the disc se has been moved into engagement with the magnet ill by the solenoid 22 But the magnet at when energized by the thermocouple 2% is not strong enough to attract and withdraw the metal disc 49, and the, stem 46 and valve disc 48 secured thereto, from the position shown in Fig. 2 to the position shown in Fig. 3. It can only hold these parts in this position aiter they have been moved thereto by the solenoid 22 through the medium of the link "13, yoke 12. plunger 5e and stem iii". After the thermostatic element it has been heated sui iciently, which is after the thermocouple has energized the mags net at, it will open the normally closed switch 2 I breaking the circuit to and (lo-energizing both the ignition element it and the solenoid 22. After the pilot burner has been ignited there is, no further need to maintain the ignition elee ment energized. As soon as the solenoid 22 is de ener'gized the spring El will return the plunger 55], stem 6?, and valve disc at back from the position shown in Fig. 3 t the position. shown in Fig. 2 against the pressure of the spring 66. The valve disc 43 will be held in the position shown in Fig. 3 by the magnet 5i, Communication is then established between the chambers to and Si through the bore 38. Gas will then flow from the chamber 35 into the chamber 3'? through the bore 33. From the chamber 31 gas will flow through the oven temperature control valve 6 and conduit 3 to the main burner l where it will be ignited by the pilot burner iii. The apparatus is now operating normally, and in the absence of any abnormal conditions it will continue to do so, provided the pilot burner remains ignited, until the supply of gas to both the pilot burner and the main burner is out on by the manual closing of the main control valve 4:.

In the event the pilot burner i5 is extinguished for any reason during operation, the thermo-; couple 25) will cool a few seconds and. deenergize the magnet El. The tie-energizing of the magnet 5! will allow the spring 58 to move the valve disc 43 back into engagement with the valve seat 39, as shown in Fig. 2, which Will, out on the flow oi? gas from the chamber till into the bore 33 and chamber 3?, and from them to the pilot light it and the main burner I. The burner i will then be extinguished along with the pilot burner. As soon as the thermostatic element It cools it will close the switch 2i which will energize both the ignition element it and the solenoid 22 as previously described since the main control valve i is still open and the switch 23 is closed. The pilot burner It will then be re-ignited and the rest of the apparatus will again function as described, provided there is gas available. If no is available everything will remain in condition to ignite the pilot burner and reinitiate operation as soon as gas is again available. In the event of either a momentary or prolonged power failure during operation, the apparatus will continue to operate normally until terminated by the manual closing of the main control valve, provideo. of course that all other conditions are normal. In order to operate the apparatus under manual control during a prolonged power failure which occurred prior to operation, it is only necessary to holda match to the pilot burner i6 and manually move the plunger 59 from the position shown in Fig. 2 to the position shown in Fig. 3 andhold it in this position a suificient time for the thermocouple 20 to become heated, after which the plunger 53 maybe released and allowed to be returned to its initial position by the spring 61. apparatus will then continue to function normally as described under the control of the pilot burner i6 and the oven temperature control valve 6, until operation is terminated by the manual closing of the main control valve 4.

When it is desired to initiate and terminate operation or the burner I automatically, the time control mechanism 30 is set to initiate operation at the desired time and to terminate operation after the burner i has been operating the desired length oi time; and the main control valve l- 5 rned t the o ti n sh wn i the 6 which ects u l. in the by a s "it an a closes he s i iilemente ma er s c At this time fuel canno fle is th ma an pilot urn r 1 in 5 im the V3 1? D in the byfl ndui ii": is lqssi. h n at the s time the m Q Z IQ methanism i 10 6 h Switch Matte which cur nt will flow r m n id of the l ne hrou h, the ad 8, switc ead H9, solen d i8 ad; o he other sid H t of the line through the leads I20 and iiii energizing the solenoid Hi3. flurrent. will also now from the switch 92 through the leads i is and. till, supplemental master switch 164 and the ea nd. H2 is he wit h 21- r h i ch 2 he. c rren v1. als fl thr u h the electric ignition element ill and the solenoid 22 and back to the other side H4 oi the line as pre viously described, thus energizing the electric ignition element It} and the solenoid 22. The solenoid Hi3 upon energizatio'n opens the normally closed valve it? in the by-pass conduit lb! and will maintain the valve 102 open as long as the solenoid is energized. fuel will now now through the by-pass con uit Hill to the safety control valve mechanism 5 and from there to the pilotburner is since the solenoid :22 is holding the salety control valve mechanism as shown in Fig. 2- ljhe pilot burner will then be ignited. by the electric ignition element it after which the apparatus will funct on as qescribeu, in connection; with manual control of the burner l, until the time control mechanism opens the switch 92'. The open ng of the switch at will brean the circuit to and ole-energize the solenoid Hi3 after which the valve it)? will automatically close and completely out oii the supply of fuel to both the main burner and the pilot burner, thus terminating operation,

As an example or} the automatic operation of the burner I let us assume that it is desired to initiate operat on of the burner i at 3 oclock and to terminate operat on thereof at 6 o'clock. The time control mechanism is then set by the button to initiate operation of the burner l at o clock accoreing to the clock iii, and by the button So to terminate operation thereof at (i ocloclr. The time control mechanism is then set in operative cond tion by button at and the main control valve is turned as shown in Fig. 6 to direct fuel through the lay-pass conduit ltil. Then at 3 ooloclr by the clocl; 9| the time control mechanism will close the switch 32 which will through the solenoid H03 and valve Hi2 initiate operation of the burner I. At 6 o'clock by the clocl; SI the time control mechanism will open the switch 02 and terminate operation of the burner I. Now let us assume that with the time control 90 set as above, there is a temporary current failure of half an hour after the burner I has been operating one hour. That would be at four oclock by the clock 9|. The current failure will stop the clock SI and de-energize the solenoid I03. The valve I02 will then close and cut off the supply of fuel to the burner I, thus stopping its operation. After half an hour the current comes back on which re-energizes the solenoid I03, since the switch 92 is still closed, and starts the clock (II operating again. The reenergization of the solenoid I03 opens the valve I02 and starts the burner I operating again. Then two hours later, at six oclock by the clock 2|, the time control mechanism will open the switch 92 and terminate operation of the burner I. From this it will be seen that the burner I operated just three hours, the set time, even though due to the half hour current failure the elapsed time from the beginning of the operation of the burner I until the final termination thereof was three and one-half hours.

In Fig. 7 I have shown a slightly modified means for automatically controlling the operation of the burner I. In this form of the invention I eliminate the supplemental master switch I04 and I place the normally open time control switch 92 in series with the normally closed switch EI by connecting the terminal I25 of the switch S2 to the lead II2 by a lead I20. Then with the main control valve 4 set for automatic operation, as shown in Fig. 6, when the time control mechanism closes the switch 92 current will flow from the side III! of the line through the lead I IS to the switch 02 and from the switch 92 through the leads I26 and H2 to the switch 2|; and through the lead II9 to the solenoid I83. From the switch 2I the current will flow through the electric ignition element I8 and the solenoid 22 and back to the other side II4 of the line as described in connection with Fig. 1; and from the solenoid I03 back to the side II4 of the line through the leads I20 and I I5. Otherwise the construction and operation of this form of the invention is the same as that shown in Fig. i and the same reference characters have been applied to like parts in the two forms. The description of the construction and operation of the invention as shown in Fig. 1 applies also to the form of the invention shown in Fig. 7.

In Fig. 8 I have shown still another slightly modified means for automatically controlling the operation of the main burner I. In this form of the invention I connect the terminal I25 of the switch 92 to the terminal I21 of the switch I04 by the lead I2I and I connect the terminal I28 of the switch I04 to the solenoid I03 by the lead I29 and I eliminate the lead IIS which connects the terminal I25 of the switch 92 to the solenoid I03. This places the switch I04 in series with the switch 02 and solenoid in one circuit as well as in series with the switch 92 and switch 2| in another circuit. Then with the main control valve set for automatic operation, as shown in Fig. 6, when the time control mechanism 90 closes the switch 92 current will flow from the side III) of the line through the lead II8 to the switch 92 and from the switch 92 through the lead I2I to the switch I04. From the switch I04 current will flow through the lead I29 to the solenoid I03 and from the solenoid I03 through the leads I20 and I I back to the other side II4 of the line.

Current will also fiow from the switch I 04 through the switch 2|, electric ignition element I8 and solenoid 22 and back to the line as described in connection with Fig. 1. Otherwise this form of the invention is the same as that shown in Fig. l and the same reference characters have been applied to like parts in the two forms. The description of the construction and operation of the invention as shown in Fig. 1 applies also to the form of the invention shown in Fig. 8.

In the form of the invention shown in Fig. 1, one might set the time control for automatic operation and forget to set the main control valve 4, in which case the time control would close the switch 92 at the set time and reopen it at the set later time. The solenoid I03 would be energized and the valve I02 held open during the time the switch 92 was closed, but since the main control valve 4 was closed and the supplemental master switch I04 was open during this time the main burner would not operate. However, this would not harm the mechanism as the solenoid I03 could be energized indefinitely without harm.

In the form of the invention shown in Fig. 7 if the time control 00 was set for automatic operation and the main control valve 4 was left closed and the switch I04 open the solenoids 22 and I03 and electric ignition element I8 would be energized during the time the switch 92 was held closed by the time control 90, but since the main valve I was closed the burner would not operate. Under these circumstances the electric ignition might burn out. This form of the invention has the advantage of the elimination of the switch I04, but it also has the disadvantage that there is a possibility of burning out the electric ignition element I8.

In the form of the invention shown in Fig. 8 both the switch 02 and the switch I04 must be closed before either the solenoid I03, the solenoid 22, or the electric ignition element I 8 can be energized. The time control 90 might be set for automatic operation and the main control valve 4 left closed, which would leave the switch I04 open, but neither the solenoids nor the electric ignition element would be energized.

From the foregoing it will be apparent to those skilled in the art that I have provided very simple and efficient mechanisms for accomplishing the objects of the invention.

It is to be understood that I am not limited to the specific constructions shown and described herein as various modifications may be made therein within the scope of the appended claims.

What is claimed is:

1. In an automatic ignition and control apparatus of the character described, the combination of a main burner, a pilot burner operative to ignite said main burner, an electric ignition element operative when energized to ignite said pilot burner, a conduit through which gaseous fuel is supplied to said main burner, a manually operable main control valve by which the supply of fuel to said main burner and said pilot burner is primarily controlled, a safety control valve mechanism interposed in said conduit between said main control valve and said main burner, a secondary conduit extending between said safety control valve mechanism and said pilot burner through which gaseous fuel is supplied to said pilot burner, said safety control valve mechanism being operative to control the supply of fuel to said main burner and said pilot burner after the fuel leaves said main control valve, a solenoid operatively connected to said safety control valve mechanism, said solenoid being operative upon energizatioh to set said safety control valve mech- 'i in condition to supply fuel to said pilot while cutting the supply of fuel to said 1d upon subsequent de energiaa safety control valve mechanism -also supply fuel to said main daily clc ed switch operative to crgization of said solenoid and said clan a thermostatic element oy pilot burner an' iaii said stitch open when c wh n cool, a lay-pass a manually operable be ng located at a junction it and by-pass and having one cio on and. two open positions op *mdve when in one open position to sti right through said conduit to said safety con trol valve "'lEChfilllSlIl and to said burners and other open posi n to direct fuel id l y-pass to said safety control valve r ec anis and d burner and when in closed to completely shut off the flow of fuel or, a normally closed valve in :ond soienoid operative when eneri normally closed valve open,

aal to effect energ ration of said electric element, said solenoid and said second and a time control mechanism opera-- so d opeiisaid time control switch thine-l l ratus of the character described, the combnoation of a main burner, a pilot burner operative to ignite main burner, an electric ignit on element operative when energized to ignite sa d pilot burner, a conduit through which gaseous fuel is supplied to said main burner, a manually operable main control valve by which the supply of fuel to said main burner and said pilot burner is primarily controlled, a safety control valve mechanism interposed in said conduit between said main control valve and said main burner, a secondary conduit eirtending betweensaid safety control valve mechanism and said pilot burner through which gaseous fuel is supplied to said pilot burner, said safety control valve mechanism being operative to control the supply offuel to said main burner and said pilot burner after the fuel leaves said, main control valve, a solenoid operatively connected to said safety control valve mechanism, said solenoid being operative upon energization to set said safety control valve mechanism in condition to supply fuel to said pilot burner while cutting off the supply of I fuel to said main burner and upon subsequent de-cnergization to set said safety control valve mechanism in condition to also supply fuel to said main burner, a by-pass around a portion of said conduit, said manually operable main control valve being located at a junction of said conduit and said lay-pass and having one closed position and two open positions and operative when in one open position to direct fuel straight through said conduit to said safety control valve mechanism and said burners and when in the other open position to direct fuel through said Icy-pass to said safety control valve mechanism and said burner and when in closed position to completely shut or? the flow of fuel to said burners, a normally closed valve in said by-pass, a second solonoid operative when energized to maintain said normally closed valve open, a normally open master control switch, a normally open time con trol switch disposed in series with said master control switch and also in series with said second solenoid and when closed operative alone to ener else said second solenoid and in conjunction with said master switch to energize said solenoid and said electric ignition element, a time control mechanism operative to close and open said time control switch at predetermined set times, a nor mally closed switch which is operative when opened to (lo-energize said solenoid and said electric ignition element, and means responsive to said pilot burner and operative to open said normally closed switch after said pilot burner has been ignited by said electric ignition element.

an automatic ignition and control apparatus as defined in claim 2 in which said means comprises a thermostatic clement adapted to be heated by said pilot burner and opera ve when heated to maintain normally closed switch open and when cool to maintain said normally closed switch closed.

In an automatic ignition and control apparatus of the character described, the combination of a main burner, a pilot burner o era tive to ignite said main burner, an electric igni tion element operative when energized to ignite pilot burner, a conduit through which gaseous fuel is supplied to said ii'lain burner, a'manw ally operable main control valve by which the supply of .luel to said main burner and said pilot burner is primarily controlled; a safety control valve mechanism interposed in said conduit between said main control valve and said main hurner, secondary conduit extend ng hetween said control valve mechanism and said pilot burr through which gaseous fuel is supplied to d pilot burner, said safety control valve mechanism being operative to control the supplyof uel to main our and said pilot turner after the fuel leaves said main control l a solenoid operatively connected to said safety control valve mechanism, said solenoid o erative upon energization to set safety control valve mechanism in condition to supply fuel to pilot burner while "cutting the supply of fuel to said main burner and subsequent de-energlzation to set safety control valve mechanism in condition to also sup-ply fuel to said main burner, a by pass around a portion of said conduit, said manually operable main control valve being located at a junction of said conduit and said i'zypass and having closed position and two open positions and operative when in one open position to direct fuel straight through said conduit to said safety control valve mechanism and to said burners and when in the other open position to direct fuel through said by-pass to safety control valve mechanism and said burners and when in closed position to completely shut off the fiow of fuel to said burners, a normally closed valve in by pass, a second solenoid operative when energized to maintain said normally closed valve open, switching means including a time control switch operative to effect cnergization of said electric ignion element, said solenoid said second solenoid, a time control mechanism operative to open and close said time control switch at predetermined set times, and means operative to (lo-energize said electric ignition element and said solenoid after said pilot burner has lace ignited said electric ignition element.

5. An automatic ignition and control appa ratus as defined in claim a in which said last mentioned means comprises a normally closed switch, and a thermostatic element adapted to be heated by said pilot burner and operative when heated to maintain said normally closed switch open and when cool to maintain said normally closed switch closed.

6. In an automatic ignition and control apparatus of the character described, the combination of a main burner, a pilot burner operative to ignite said main burner, an electric ignition element operative when energized to ignite said pilot burner, a conduit through which gaseous fuel is supplied to said main burner, a manually operable main control valve by which the supply of fuel to said main burner and said pilot burner is primarily controlled, a safety control valve mechanism interposed in said conduit between said main control valve and said main burner, a secondary conduit extending between said safety control valve mechanism and said pilot burner through which gaseous fuel is supplied to said pilot burner, said safety control valve mechanism being operative to control the supply of fuel to said burner and said pilot burner after the fuel leaves said main control valve, a solenoid operatively connected to said safety control valve mechanism, said solenoid being operative upon energization to set said safety control valve mechanism in condition to supply fuel to said pilot burner while cutting oif the supply of fuel to said main burner and upon subsequent deenergization to set said safety control valve mechanism in condition to also supply fuel to said main burner, a by-pass around a portion or" said conduit, said manually operable main control valve being located at a junction of said conduit and said by-pass and having one closed position and two open positions and operative when in one open position to direct fuel straight through said conduit to said safety control valve mechanism and to said burners and when in the other open position to direct fuel through said by-pass to said safety control valve mechanism and said burners and when in closed position to completely shut off the flow of fuel to said burners, a normally closed valve in said by-pass, a second solenoid operative when energized to maintain said normally closed valve open, a normally open master control switch, operative connections between said main control valve and said master switch through which said master control switch is closed by the setting of said main control. valve to direct fuel through said bypass, a normally closed switch disposed in series with said master switch and said electric ignition element and with said master switch and said solenoid, means operative to open said normally closed switch after said pilot burner has been ignited by said electric ignition element, a time control switch disposed in series with said master switch and in series with said second solenoid, and a time control mechanism operative to close and open said time control switch at predetermined set times, said time control switch when closed being operative alone to energize said second solenoid and in conjunction with said master switch to energize said electric ignition element and said solenoid and said normally closed switch being operative when opened to deenergize said electric ignition element and said solenoid.

'7. An automatic ignition and control apparatus as defined in claim 6 in which, said means operative to open said normally closed switch after said pilot burner has been ignited by said elec- 16 tric ignition element comprises, a thermostatic element adapted to be heated by said pilot burner and operative when heated to maintain said normally closed switch open and when cool to maintain said normally closed switch closed.

8. In an automatic ignition and control apparatus of the character described, the combination of a main burner, a pilot burner operative to ignite said main burner an electric ignition element operative when energized to ignite said pilot burner, a conduit through which gaseous fuel is supplied to said main burner, a manually operable main control valve by which the supply of fuel to said main burner and said pilot burner is primarily controlled, a safety control valve mechanism interposed in said conduit between said main control valve and said main burner, a secondary conduit extending between said safety control valve mechanism and said pilot burner through which gaseous fuel is supplied to said pilot burner, said safety control valve mechanism being operative to control the supply of fuel to said main burner and said pilot burner after the fuel leaves said main control valve, a solenoid operatively connected to said safety control valve mechanism, said solenoid being operative upon energization to set said safety control valve mechanism in condition to supply fuel to said pilot burner while cutting off the supply of fuel to said main burner and upon subsequent de-energization to set said safety control valve mechanism in condition to also supply fuel to said main burner, a by-pass around a portion of said conduit, said manually operable main control valve being located at a junction of said conduit and said by-pass and having one closed position and two open positions and operative when in one open position to direct fuel straight through said conduit to said safety control valve mechanism and to said burners and when in the other open position to direct fuel through said by-pass to said safety control valve mechanism and said burners and when in closed position to completely shut off the flow of fuel to said burners, a normally closed valve in said by-pass, a second solenoid operative when energized to maintain said normally closed valve open, a normally open master control switch adapted to be closed by the setting of said main control valve to direct fuel straight through said conduit, a normally closed switch in series with said master switch and said electric ignition element and with said master switch and said solenoid, means operative to open said normally closed switch after said pilot burner has been ignited by said electric ignition element, a normally open supplemental master switch adapted to be closed by the setting of said main control valve to direct fuel through said by-pass and disposed in series with said normally closed switch, a normally open time control switch disposed in series with said supplemental master switch and with said second solenoid, and a time control mechanism operative to close and open said time control switch at predetermined set times, said master switch being operative when closed to energize said electric ignition element and said solenoid, said time control switch when closed being operative alone to energize said second solenoid and in conjunction with said supplemental master switch to energize said electric ignition element and said solenoid, and said normally closed switch being operative when opened to deenergize said electric ignition element and said solenoid.

9. An automatic ignition and control apparatus as defined in claim 8 in which, said means operative to open said normally closed switch after said pilot burner has been ignited by said electric ignition element comprises, a thermostatic element adapted to be heated by said pilot burner and operative when heated to maintain said normally closed switch open and when cool to maintain said normally closed switch closed.

10. In an automatic ignition and control apparatus of the character described, the combination of a main burner, a pilot burner operative to ignite said main burner, an electric ignition element operative when energized to ignite said pilot burner, a conduit through which gaseous fuel is supplied to said main burner, a manually operable main control valve by which the supply of fuel to said main burner and said pilot burner is primarily controlled, a safety control valve mechanism interposed in said conduit between said main control valve and said main burner, a secondary conduit extending between said safety control valve mechanism and said pilot burner through which gaseous fuel is supplied to said pilot burner, said safety control valve mechanism being operative to control the supply of fuel to said main burner and said pilot burner after the fuel leaves said main control valve, a solenoid operatively connected to said safety control valve mechanism, said solenoid being operative upon energization to set said safety control valve mechanism in condition to supply fuel to said pilot burner while cutting off the supply of fuel to said main burner and upon subsequent deenergization to set said safety control valve mechanism in condition to also supply fuel to said main burner, a bypass around a portion of said conduit, said manually operable main control valve being located at a junction of said conduit and said by-pass and having one closed position and two open positions and. operative when in one open position to direct fuel straight through said conduit to said safety control valve mechanism and said burners and when in the other open position to direct fuel through said by-pass to said safety control valve mechanism and said burner and when in closed position to completely shut off the flow of fuel to said burners, a normally closed valve in said by-pass, a second solenoid operative when energized to maintain said normally closed valve open, a normally open master control switch, a normally open time control switch disposed in series with said master control switch and said second solenoid, said master switch and said time control switch being operative when both of said switches are closed to effect energization of said electric ignition element, said solenoid and said second solenoid, a time control mechanism operative to close and open said time control switch at predetermined set times, a normally closed switch which is operative when opened to deenergize said solenoid and said electric ignition element, and means responsive to said pilot burner and operative to open said normally closed switch after said pilot burner has been ignited by said electric ignition element.

11. An automatic ignition and control apparatus as defined in claim 10 in which said means comprises a thermostatic element adapted to be heated by said pilot burner and operative when heated to maintain said normally closed switch open and when cool to maintain said normally closed switch closed.

12. In an automatic ignition and control apparatus of the character described, the combination of a main burner, a pilot burner operative to ignite said main burner, an electric ignition ele ment operative when energized to ignite said pilot burner, a conduit through which gaseous fuel is supplied to said main burner, a manually operable main control valve by which the supply of fuel to said main burner and said pilot burner is primarily controlled, a safety control valve mechanism interposed in said conduit between said main control valve and said main burner, a secondary conduit extending between said safety control valve mechanism and said pilot burner through which gaseous fuel is supplied to said pilot burner, said safety control valve mechanism being operative to control the supply of fuel to said main burner and said pilot burner after the fuel leaves said main control valve, a solenoid operatively connected to said safety control valve mechanism, said solenoid being operative upon energization to set said safety control valve mechanism in condition to supply fuel to said pilot burner while cutting off the supply of fuel to said main burner and upon subsequent deenergization to set said safety control valve mechanism in condition to also supply fuel to said main burner, a by-pass around a portion of said conduit, said manually operable main control valve being located at a junction of said conduit and said by-pass and having one closed position and two open positions and operative when in one position to direct fuel straight through said conduit to said safety control valve mechanism and said burners and when in the other open position to direct fuel through said by-pass to said safety control valve mechanism and said burner and when in closed position to completely shut off the flow of fuel to said burners, a normally closed valve in said bypass, a second solenoid operative when energized to maintain said normally closed valve open, a normally open time control switch which is operative when closed to effect energization of said electric ignition element, said solenoid and said second solenoid, a time control mechanism operative to close and open said time control switch at predetermined set times, a normally closed switch which is operative when opened to deenergize said solenoid and said electric ignition element, and means responsive to said pilot burner and operative to open said normally closed switch after said pilot burner has been ignited by said electric ignition element.

13. An automatic ignition and control apparatus as defined in claim 12 in whcih said means comprises a thermostatic element adapted to be heated by said pilot burner and operative when heated to maintain said normally closed switch open and when cool to maintain said normally closed switch closed.

CHARLES M. MAYER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,303,672 Wantz Dec. 1, 1942 2,353,042 Koch July 4, 1944 2,478,386 Gauger Aug. 9, 1949 2,483,191 Gauger Sept. 27, 1949 2,562,536 Mayer July 31, 1951 2,564,869 Weber Aug. 21, 1951 2,577,787 Mayer et al Dec. 11, 1951 2,578,717 Mayer et a1 Dec. 18, 1951 2,578,718 Mayer Dec. 18, 1951 2,584,147 Mayer Feb. 5, 1952