US2645280A

US2645280A - Single point ignition

Info

Publication number: US2645280A
Authority: US
Inventors: Witzel Ernst
Original assignee: Milwaukee Gas Specialty Co
Current assignee: Milwaukee Gas Specialty Co
Priority date: 1947-04-30
Filing date: 1947-04-30
Publication date: 1953-07-14
Anticipated expiration: 1970-07-14

Description

July 14, 1953 1;. WITZEL SINGLE POINT IGNITION 3 Sheets-Sheet 1 Filed April 30, 1947 J72Ue/7Z57 "7262 1022361 mu I y 4, 1953 E WITZEL 2,645,280

SINGLE POINT IGNITION Filed April 30, 1947 3 Sheets-Sheet 3 25 J I J! J I .7 0 V g 6.9 J2 a H 61 J4 .15

I III '1 88 I if m 17 .56 87 J7 V J2? 35 A 4577252 Z/JL'Z" 91 l mb/00% Patented July 14, 1953 UNITED STATES PATENT OFFICE SINGLE'POINT IGNITION Ernst Witzel, Milwaukee, assignor' to Milwaukee Gas SpeeialtyCompany, Milwaukee, I Wis., a'corporation of Wisconsin 7 Application April 30, 1947, Serial No. 744,905 H Claims. "(or 158-124) This invention relates, in general, to ignition systems and has particular relation to an improved single point ignition system for. fuel burners.

While the particular embodiment of the invenw tion which I shall describe herein fter in con:

nection with the drawings is a single point ignition systeinadapted for use with domestic gas ranges, it is to be understood that theinvention is not limited to such use, but may be employed for all.

similar purposes, for example, in connection with various commercial forms of apparatus having a baking oven burner, broiler oven burner or other burner remotely located relative to the pilot burner. l

In the usual domestic gas range, the pilot burner is inthe form of a single, constantly burning pilot burner locatedin juxtaposition to the top burners at the upper-part of the range, and the baking oven, broiler or like burners, are located in the lower part of the range. Although the top burners are. usually provided with a con stantly burning pilot burner for lighting the same, at the present time a match is usually eme, ployed for lighting the baking oven, broiler or like burners. The stooping and hazards of lighting an oven burner or the like with a match are well known in the art.

In my copending application, Serial No. 738,412,

filed March 31, 1947, I provide an improved system of flash-tubes and intermediate pilot-burner means for assuring ignition ofa pilot burner in juxtaposition to the oven or like burner from a constantly burning top pilot burner; also an improved single point ignition system wherein means is provided for extinguishing the intermediate.

pilot burner means and establishing a flow of fuel to the oven or like burner aftera time delay following ignition of the pilot burner for igniting the main burner, and an improved thermoelec-;

the only item requiring actuationmanually to,

secure the desired single point ignition. Another object of the invention is to provide single point ignition system in which the main thermoelectric control device (such asa valve) maybe located wherever convenient outside the improved form of thermoelectric control device for extinguishing the intermediate pilot burner means and establishing a flow of fuel to the oven or like burner after a time delay following ignition of the pilot burner for igniting the main burner; also an improved form of thermoelectric control device which will shut off or prevent the supply of fuel to the oven pilot burner and to the intermediate pilot burner means and oven burner in case the oven or like pilot burner is extinguished or fails to ignite.

Another object of the invention is to provide an improved thermoelectric control device in which a thermocouple or other thermoelectric generator heated by the oven pilot burne' is adapted to energize its connected electromagnet sufliciently during the time delay to open the main thermoelectric valve and to hold it open.

Another object of the invention is to provide a single point ignition system and instrumentalities therein, as will hereinafter appear, having Various features of novelty and advantages and which are particularly characterized by their simplicity in construction, their economy in manufacture and installation, and their effectiveness in use.

Further objects and advantages of the inven-- tion will appearirom the following detailed description, taken in connection with the accompanying drawings which illustrate the manner of constructing and operating an illustrative embodiment of the invention.

In the drawings:

Figure ,1 is a diagrammatic view showing a single point ignition system embodying the pres ent invention; 7 t

Figure 2 is a sectional view taken axially through the thermoelectric control device shown in Figure 1; and t Figure 3 is an axial section taken substantially on theline 3-3 of Figure 2.

Referring now to the drawings, the burner I .is the baking oven, broiler or other remote burner. It is usually located in the lower part of the range or other appliance.

The pilot burner 2 is the constantly burning pilot burner. It may be, for example, the top pilot burner for the top burners of a gas range or other constantly burning pilot burner. The

' 6 or other gas shut-off means connected into the pipe 3 anterior of the valve 5 and operable to open and close the fuel line. Where hereinafter, in the specification and in the appended claims, I refer to a gas cook, I intend to include within: that terminology the gas cock" shown in the suitable character, or in the formof a thermopile or other thermoelectric generator. The thermoelectric generator has one or more hot junctions,

for example the hot junction 4|, which is placed in position to be heated by the flame 42 of the pilot burner I.

Inthe; illustrated embodiment of the invention, the electromagnet has a flux shell 45 and a spacer ring 46. The lower end of'the coil spool 30 has an axial recess, and disposed in this recess and interposed between spool 30 and armature 25 is a eoi led spring 41 which operates to move armature 25 to retracted positiqn and to seat the valve 26 drawings and all other gas shut-off means such as a remotely controlled solenoid valve and. all

other means of shutting off the gas supply.

The oven or like burner l is provided with an oven or like pilot burner Tfor igniting it. A flash tube 8 has a laterally turned upper end opening 1 directly tothe constantly burning pilot burner'2'.

This tube extends downwardly and opens at its lower end to an intermediate pilot burner 9; The intermediate pilot burner 9 is spaced laterally from the oven pilot burner 1, and the tube 8 has at its lower end a generally horizontally extending branch 8 which opens at its outer end directly over the flame position ID ofthe oven pilot; burner 1.

The thermoelectric control device 5 com-prisesa valve body formed of top and bottom valve body parts [5 and i6 clamped together by screws H with a diaphragm l3 therebetween. The valve body part l5 has an inlet 19 and an outlet 20. Contiguous sections of the fuel supply pipe 3 are connected to the inlet is and outlet 20, for ex-' ample, by screwing them into the inlet and outlet which are shown as internally threaded. Internally, the valve body part l5 has a generally- L-shaped outlet chamber 2| having a longitudinally extendingpart in open communication with the outlet 20 and a transversely extending portion defined by a cylindricalwall 22. An inlet chamber 23, in open communication with the inlet 1-9,

terminates at its inner-end in a generally annularshaped portion which embraces the cylindricalwall 22.

The wall 22 terminates in an annular valve-seat 24. An armature 25, of disc-like form, has a yielding or other suitable valve or valve facing 26 adapted to seat against the seat 24 to shut offthe flow of gas from. inlet l9 to outlet 20 through chamber 2|. body part I5 by a union nut 28, and preferably; with a hood gasket 28 therebetween.

In the illustrated embodiment of the invention,v the means for operating the valve 26, and more particularly the means for opening this valve,.'is in, the form of an electromagnet comprising a magnet frame or coil spool 30 and a 0011 3!. One side of the coil 3| is connected by a lead 32 to one of the thermocouple elements 33 of a thermocouple 34 or other suitable thermoelectric generator (such as a thermopile). The other element 35 of the thermocouple 34 is connected by a lead 38 to one contact 31 of a tilting mercury switch 38 (Figure 2) within the valve body part IS. The

' other and adjacent contact 39 of the switch 38 is on valve seat 24 when the electromagnet is deenerg-i zed," Energization of the electromagnet by heating of the hot junction of the thermocouple "3,4; is. sufficient, to, lift valve 26 to open position .againstthe action of spring 41. A hood spring 48, interposed between the top of the spool 30 and hood 21, seats the shell in the valve body part [5 at-49. Y In commercial practice, one of the thermocouple elements, for examplethe outer tubular thermocouple element 33, may be grounded and,.

as shownin Figure 3, the lead 410. between the A hood 2.1. is clamped to thev valve.

otherside of the coil. and thelmercury'switch contact 39 may be connectedto. a terminali block 5|, which, in turn, is connected by connector leads. 52. and 53 and-wire lead- 54 to contact 3.9. Theother contact 31 is shown connected. by wire lead 55. to. a connector lug 56 which is. connected in. circuit.

with a terminaltip -51: havinga conical. depression in its outer end into contact withwhich a termi'-. nal cone (not shown) on the adjacent. end of conductor is-adaptedto be detachably clamped;

by a sleeve (notshown) screwed into the. threaded socket 58 in thevalveibody part IS.

The bottom of thevalvebody part. l5.has-. a recess 60 spaced;inwar.dly1 from. itsperipheryl Dis.-

posed in thisrecess andv above. diaphragm l8 is-a.

cover platefil clamped to valve body part I.5.by screws 5| (Figure-3.) with adiaphragmSZ: there! between. A. port 83 opensfrominlet chamber.- 23

intochamber- 64 abovediaphragm 62'. Another port 65- opens-from. inlet chamber 231 into chamber '66 above diaphragm l8.

The-valve body. part l5-has a pilot. outlet; passage 61 forsupplying fuel to the intermediate pilot burner Q-through a pipe 68; which maybe screwed: into the. pilot. outlet. .6 9;. Fuel. is adapted to be deliveredfromthe diaphragmchamber 6.4 to the passage 61 through a passage. 1.0, the. lower end of which is surrounded by an annularv valve; A valve or valve. facing member 12 is. adapted to seat. against seat H to shut off thesupply of fuel to the-intermediatepilotburner 9 Phe pilot'burner T is supplied withfuel: by-apipe 13 connected at I4, for-example, to thefuel supply Valveor'valve facing-l2; wh-ich is of disc-like. form, is secured to the diaphragm 62- at the axis thereof bya, rivet I8; Thediaphr-agm 62 may have diaphragm plates, and interposed between the bottom of this diaphragm and co-verplate 5| is a spring; 1-9: A portBOopens from the outlet- 7 chamber Hand-through port 8-l-into chamber 82- beneath diaphragm 62-;

The mercury bulb 38" of-the mercur-y'switch is The constantly burning pilotholder bracket 81. The bulb holder 85 has pins 88 which are engaged by the notched lower ends of the depending legs of a diaphragm bracket .89. The diaphragm I8 may have diaphragm plates 90,,and bracket 89 is secured to the diaphragm I8 at the axis thereof by a rivet 9 I. A' spring arm 92 is notched at one end at 93 for engagement of pins 88 therein. The other end of arm 92 is notched at 94 for engagement with a pin v95. The pin 95 is carried by a spring arm bracket 96 secured in place by screws 91. A coiled spring 98 is interposed between the arm 92 and the base of bracket 96.

A diaphragm holding ring I is secured by 3 screws II to the bottom of the interiorof valve body part I8, with a diaphragm I02 clamped therebetween. A port I03 opens Into the air chamber I04 within valve body part I6 below diaphragm I8. Passage I05, which is adapted for placing chamber I06 beneath diaphragm I02 in communication with port I03, is surrounded at its upper end by an annular valve seat I01. A valve or valve facing member I08 is adapted to seat against seat I01 to shut oif communica tion between chamber I06 and the air chamber I04 within valve body part I6. Valve or valve facing I08, which is of disc-like form, is secured to the diaphragm I02 at the axis thereof by a rivet I09.

A filter cover plate I I0 is secured .by screws II I to the bottom of the valve body part IS with an air filter II2 clamped marginally therebetween. A port I I3 (Figure 3) opens from chamber I96 beneath diaphragm I02 into chamber II4 above filter II2. Chamber II 5, beneath filter II2, opens to atmosphere through port IIfi.

For adjustable time delay as will hereinafter appear, the air below diaphragm I8 is prevented from quick escape by an adjustable time delay device in the form of a tapered pin I 20 fitted into or cooperating with a tapered bore I2I. A port I22 places the interior of chamber, I04 beneath diaphragm I8 in communication with bore I2I, and a passage I23 places the inner end of the bore I2I in communication with chamber sired position. The opening through which access to pin I20 is obtained may be closed by a plug I21 screwed into valve body part I8.

The operation of the system shown in the drawings is as follows:

When gas cock '8 is opened gas is admitted to the tops of diaphragms 62 and I8 by

meansof ports

63 and 65. Valve 12 will open against the pressure of spring 19, and gas will flow to the intermediate pilot9 through passage 81 and pipe or tube "68. gas to pilot burner 1 through pipe or tube 13.

The gas from the intermediateand oven pilot.

burners rises in tube 8, which is always relatively cool to permit this action. As it reaches the flame of constantly burning pilot burner 2 the gas is ignited and then recedes or flashes back to light the intermediate and

burner pilot burners

9 and 1. The turningof the upper end of the flash tube laterally toward pilot burner 2 reduces the possibility of extinguishing this pilot burner by flash back action in tube 8.

Opening of gas cook 6 also admits Thermocouple 33 is now heated and energizes electromagnet 30, 3| which lifts valve 26 and admits gas to theoven burner I through outlet 20 and fuel supply pipe 3. 'A gas pressureis now. established on the outlet :side' of valve 5, and gas will flow through ports 80 and BI to the under side of diaphragm 62., This neutralizes pressures on opposite sides of diaphragmcBZ, and valve 12 closes with the help of spring] 9, thereby stopping or shutting on the supply of gas to the intermediate pilot burner 9. In: the event gas cook 6 is now closed and immediately opened again, it could occur that there would be sufficient power in the electromagnet 30, 3| to keep valve 26 in open position. In such case'valve 12 would stay closed,

pilot burners

9 and 1 would not ignite, and unburned gas would stream from the oven burner, thereby creating a dangerous hazard. V p

In order to prevent such occurrence the time delay and switch system functions as follows;

When the gas cook 8 is opened and gas pres sure is established above diaphragm I8 through port 65, the air in chamber I04 below this di-. aphragm is prevented from quick escape by the tapered time delay pin I20. The adjustment of this pin determines the quickness of escape of the air, and thereby the time delay. The delay is timed to assure closing of the valve 26 and thereby shutting off of the fuel supply to the main burner whenever the gas cook 8 is closed even though only momentarily. j V

The air escapes only slowly as determined by the position of pin I20, and follows the path through ports I22, I23, through air filter H2, and discharging into the atmosphere through port H6. The diaphragm I8 will therefore move only slowly and finally tip mercurybulb 38 in a counterclockwise direction, as viewed in Fig, ure 2, sufficiently to make contact at 31, 39 to complete the electric circuit between the thermocouple or other thermoelectric generator 33 and coil 3|.

Whenever the gas cook 6 is closed the di'- aphragm I8 must return quickly into neutral position so that in case the valve 6 is opened again immediately, the'diaphragm I8 will bein uppermost position for a new time delay cycle. The passage (I22, I2I, I23, H2, and II'B)'is not suitable for this operation, and the other means comprising the diaphragm I02 has therefore been provided. When the gas cook 6 is closed, gas

pressure on the diaphragm I8 is eliminated and.

spring 98 will endeavor to return the diaphragm I8 into top position, and, indoing so, a suction ure 3, port or passage I03 leads to a passage I03 which opens at its upper end into the cham;

ber I04. This air passage is unrestricted and will therefore tend to replace the air quickly.

In operation, thevalve I08 must close tightly,

on the downward stroke of diaphragm I8 so that tight seal is accomplished by means of thediaphragm I02 whose area is much larger than the valve seat 1 area I 01, and therefore exerts correspondingly larger pressure on valve seat I01 to oppose the wardly. y

plate other forms of thermostats-and other forms 7 off thermostatic controls than the one shown in Figure 1 of the drawings, which is for purposes of illustration.

The present invention contemplates many variations in the form and details of the thermostatic control device 5, and many variations'in the form of the single point ignition system with which it is shown in the drawings. The embodiment of the invention shown in the drawings is, therefore, for illustrative purposes only, and it is to be expressly understood that the drawings and the accompanying specification are not to be construed as a definition of the limits or scope of the invention, reference being had to the appended claims for that purpose.

I claim:

1. In apparatus of the class described, in combination, a; first constantly burning pilot burner, a burner remote from said first pilot burner, a second pilot burnerin proximity to said burner for lighting same, a third pilot burner intermediate said first and second pilot burners for assuring ignition, of said second pilot burner from said first pilot burner, a fuel supply line for supplying fuel to said burner and said pilot burners, said first, second and third pilot burners each being connected to said fuel supply line to receive fuel therefrom, valve means to open and close said fuel supply line posterior of the fuel supply to said first pilot burner, a first valve member in said fuel supply line on the outlet side. of said valve means and posterior of the fuel supplyvto said second pilot, burner, said valve member having anopen positionor flow of fuel to said burner and closed position shutting ofi'the flow of fuel to said burner, a second valve member in. said fuel supply line on the outlet side of said valve means and posterior of the fuelsupply to said second pilot burner, said second valve member having means responsive to the, pressure of the fuel in said fuel supply line; when said valve means is opened and operable by the fuel pressureto open position only when said first valve member is closed for the flow of. fuel to said'third pilot burner, the pressure responsive means of said second valve memto equalizing fuel pressure when said first valve" member is open. 7 v

3. Apparatus according to claim 1 wherein there is a thermoelectric generator subject to the heat of said second pilot burner and an electromagnet adjacent to said first valve member and connected in circuit with said thermo-' electric generator for operating said'first valve member to. open position.

4. In apparatus of the class described, in combination, a first constantly burning pilot burner, a burner remote from said pilot burner, a second pilot burner in proximity to .said burner for lighting-same, a third pilot burner intermediate said first and second pilot burners for assuring ignition of said second pilot burner from said first pilot burner, a fuel supply line having fuel supply connection with said main burner and fuel supply connections with said pilot burners for supplying fuel to said burner and said pilot burners, valve means to open and close said fuel supply lineposterior of the fuel supply connection to said first pilot burner, a first valve member in said fuel supply lineon the outlet side of said valve means and posterior of the fuel supply connection to said second pilot burner, said valve member having an open position for flow of fuel to said. burner and closed position shutting off the fiowof fuel to said burner, a.

second valve member in said fuel supply line onthe outlet side of said valve means and posterior of the fuel supply connection to said second pilot burner, said second valve member having means responsive to the pressure of the fuel in said fuel supply line when said valve means is opened and operable by the fuel pressure to open 7 position only when said first valve member is closed for the fiow of fuel to said third pilot open position, 'a switch in the circuit for said electromagnet and said thermoelectric generator, and means responsive to the pressure of the fuel in said fuel supplyline on the inlet side of said first valve member for actuating said. switch to closed position.

5. Apparatus according to claim 4 wherein there is a chamber having a relatively restricted outlet, and wherein the means responsive to the pressure of the fuel in said fuel supply line on the inlet side of said first valve member for actuating said switch to closed position comprises a diaphragm subject on one side to the pressure in said chamber whereby with the restricted outlet for said chamber to provide a time delay in closing said switch following ignition of said second pilot burner.

6. Apparatus according to claim 4 wherein I there is a chamber having a relatively restricted outlet, and wherein the means responsive to the pressure of the fuel in said fuel supply line on the inlet side of said'first valve member for actuating said switch to closed position comprises a diaphragm subject on one side to the pressure in said-chamber whereby with the restricted outlet for'said' chamber to provide a time delay in closing said switch following igni- Vtion of said second pilot burner, there also being a diaphragm subject on one side to the pressure in said chamber whereby with the restricted outlet from said chamber to provide a-time delay in closing said switch following ignition of said sec:

0nd pilot burner, and wherein there is means for adjusting said relatively restricted outlet to adjust the amount of time delay in closing said switch following ignition of said second pilot burner.

'8. Apparatus according to claim 4 wherein there is a chamber having a relatively restricted outlet, and. wherein the means responsive to the pressure of the fuel in said fuel supply line on the inlet side of said first valve member for actuating said switch to closed position comprises a diaphragm subject on one side to the pressure in said chamber whereby with the restricted outlet from said chamber to provide a time delay'in closing said switch following ignition of said second pilot burner and wherein there is spring means for returning said diaphragm to the position which it occupies when said valve means is closed and said switch comprises a tilting mercury switch disposed within said chamber.

9. In a control device of the class described, in combination, a valve'body having an inlet for receiving fluid under pressure and a first fluid outlet, a first valve member having closed position shutting off the flow of fluid from said inlet to said first outlet and open position for flow of fluid from said inlet to said first outlet, said valve body having a second fluid outlet, a second valve member having closed position shutting off the flow of fluid from said inlet to said second outlet and open position for flow of fluid fromsaid inlet to said second outlet, means responsive to the pressure of the fluid entering said inlet to open said second valve member when said first valve member is closed and responsive to equalizing fluid pressure for closing of said second valve member when said first valve member opens, an electromagnet adjacent to said first valve member for operating said first valve member to open position, a switch connected in circuit with said electromagnet, and means responsive to the pressure of the fluid on the inlet side of said first valve member for actuating said switch to closed position.

10. A device according to claim 9 wherein there is a chamber having a relatively restricted outlet and wherein the means responsive to the pressure of the fluid on the inlet side of said first valve member for actuating saidswitch to closed position comprises a diaphragm subject on one side to the pressure in said chamber whereby with the restricted outlet for said chamber to provide a time delay in closing said switch.

11. A device according to claim 9 wherein there is a chamber having a relatively restricted outlet and wherein the means responsive to the pressure of the fluid on the inlet side of said first valve member for actuating said switchto closed position comprises a diaphragm subject on one side to the pressure in said chamber having a relatively restricted outlet whereby with the restricted outlet for said chamber to provide a time delay in closing said switch, there also being 10 means for establishing free admission of air into saidchamber whereby said diaphragm will return quickly to normal position.

12. A device according to claim 9 wherein there is a chamber having a relatively restricted outlet and wherein the means responsive to the pressure of the fluid on the 'inlet side of said first valve member for actuating said switch to closed position comprises a diaphragm subject on one side to the pressure in said chamber whereby with the restricted outlet for said chamber to provide a time delay in'closing said switch, there also being means for adjusting said relatively restricted outlet to adjust the amount of time delay in closing said switch. 7

13. A device according to claim 9 wherein there is a chamber having a relatively restricted outlet and wherein the means responsive to the pressure of the fluid on the inlet side of said first valve member for actuating said switch to closed position comprises adiaphragm subject on one side to the pressure in said chamber whereby with the restricted outlet for saidchamber to provide a time delay inclosing said switch, there also being spring means for returning said diaphragm to its normal position and said switch comprises a tilting merouryswitch disposed within said chamber. a

14. In a control device of the class described, in combination, a valve body having an inlet for receiving fluid under pressure and a first fluid outlet, a first valve member having closed posi' tion shutting off the flow of fluid from said inlet to said first outlet and open position for flow of to said second outlet, means responsive to the pressur of the fluid entering said inlet-to open said second valve member when said first valve member is closed and responsive to equalizing fluid pressure for closing of said second valve member when said first valve member opens, and means responsive to the pressure of the fluid entering said inlet for producing a time delay after opening of said second valve member before said first valve member opens.

15. A device according to claim 14 wherein there is an electromagnet which, when energized, is adapted to open said first valve member, and wherein there is means responsive to the pressure of the fluid entering said inlet for producinga timedelay after opening of said second valve member before said electromagnet is energized.

ERNST WITZEL.

References Cited in the file of this patent