US2527286A

US2527286A - Safety shutoff control for plural pilot gaseous fuel burner systems

Info

Publication number: US2527286A
Application number: US748969A
Authority: US
Inventors: Witzel Ernst
Original assignee: Milwaukee Gas Specialty Co
Current assignee: Milwaukee Gas Specialty Co
Priority date: 1947-05-19
Filing date: 1947-05-19
Publication date: 1950-10-24
Anticipated expiration: 1967-10-24

Description

E. WITZ 2,527,286 SAFETY SHUTOFF CONTROL FOR PLURAL PILOT GASEOUS FUEL BURNER SYSTEMS 2 heets-Sheet 1 Filed Ma 19 1947 J kw. w u 5% Filed May 19, 1947 E. WITZEL SAFETY SHUTOFF CONTROL FOR PLURAL PILOT GASEOUS FUEL BURNER SYSTEMS 2 Sheets-Sheet 2 Patented Oct. 24, 1950 UNITED STATES PATENT OFFICE SAFETY SHUTOFF CONTROL FOR PLURAL PILOT GASEOUS FUEL BURNER SYSTEMS Ernst Witzel, Milwaukee, Wis., assignor to Milwaukee Gas Specialty Company, Milwaukee, Wis., a corporation of Wisconsin 7 Application May 19, 1947, Serial No. 748,969

14 Claims.

ignition system adapted for use with domestic gas ranges, it is to be understood that the invention is not limited to such use but maybe employed for all similar purposes, for example, in connection with various commercial forms of aparatus having a baking oven burner, broiler oven burner, or other burner remotely located relative to the pilot burner.'

In the usual domestic gas range, the pilot burner is in the form of a single constantly burning pilot burner located in juxtaposition to the 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 constantly burning pilot burner for lighting the same, at the present time a match is usually employed for lighting the baking oven, broiler or like burners.

The stoo'oing 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 of a 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 after a time delay following ignition of the pilot burner in juxtaposition to the main burner, and an improved thermoelectric control device and other instrumentalities for accomplishing the new and advantageous results therein set forth.

In my copending application, Serial No. 744.905, filed April 30, 1947, I provide a simple, improved and effective single point ignition system which will provide all of the advantageous results obtained with the systems disclosed and cla med in my above identified copending application and in which the gas cock or other valve m ans to vention which I shall describe hereinafter in connection with the drawing is a single point 'top' burners at the upper part of the range, and

open and close the fuel line is the only item re-.

quiring actuation manually to secure the desired single point ignition.

One of the main objects of the present invention is to provide a simple, improved and effective single point ignition system of the character shown and described in my above identified copending applications, and in which the gas cook or other valve means to open and close the fuel line is not only the only item requiring actuation manually to secure the desired single point ignition, but accomplishes these results without parts actuated by diaphragms or otherwise by the pressure of the fuel in the fuel supply line.

Another object of the invention is to'provide an improved form of control in which valve means controlling the supply of fuel to one or more intermediate pilot burners is opened by operation of the aforesaid valve means to open position.

Another object of the invention is to provide an improved form of control in which opening of the valve means for the intermediate pilot burner means by the operation to open position of the valve means for opening and closing the gas line establishes a supply of fuel to'the intermediate pilot burner means for igniting the pilot burner in juxtaposition to the main burner and in which the intermediate pilot burner means is extinguished and a supply of fuel established to the oven or like burner aftera time delay following ignition of the pilot burner in juxtaposition to the main burner.

Another object of the invention is to provide, an improved form of thermoelectric control device for accomplishing the advantageous results set forth; more particularly, an improved form of thermoelectric control device characterized by simplicity in construction, its economy in manufacture and installation, and its effectiveness in use.

Further objects and advantages of the invention will appear from the following detailed description, taken in connection with the accompanying drawings which illustrate certain embodiments of the invention.

In the drawings:

Figure 1 is a diagrammatic view of one form of single point ignition system and thermoelectric control device embodying the present invention; Figure 2 is an enlarged fragmentary sectional view of a portion of the thermoelectric control device shown in Figure 1;

Figure 3 is a circuit diagram of the thermoelectric control; and

Fig. 4 is a view showing fragmentarily and insection an arrangement which will permit grounding of the thermocouple connectors.

Referring now to the drawing, the burner l is the baking oven, broiler or other remote burner.

It is usually located in the lower part of the range or other apliance.

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 pilot burner 2 is usually located in the upper part of the appliance.

A fuel supply pipe 3 leads to the burner I for the delivery of gaseous or other fuel thereto, for example, through a mixing chamber 4 to which air is admitted through adjustable air inlets (not shown) as well understood in the art. The flow of gas through the pipe 3 is controlled by a thermoelectric control device 5 connected into the pipe 3.

The oven or like burner l is provided with an oven or like pilot burner l for igniting it. An intermediate pilot burner 8 is located in juxtaposition or in functional relation to the constantly burning pilot burner 2. A flash tube 9 has its upper end opening directly to the intermediate pilot burner 8. This tube extends downwardly and is shown as opening at its lower end to a second intermediate pilot burner I 0. The intermediate pilot burner I is spaced laterally from the pilot burner I, and the tube 9 has at its lower end a generally horizontally extending branch 9' which opens at its outer end directly over the flame position ll of the pilot burner I.

The thermoelectric control device comprises a valve body l5 having an inlet l6 and an outlet Contiguous sections of the fuel supply pipe 3 are connected to the inlet I 6 and outlet IT, for example, by screwing them into the inlet and outlet, which are shown internally threaded. Gas shut-off means, shown in the form of a gas cock l8, has, for example, a, tapered plug part rotatable in the wall or the valve body l5 adjacent to inlet l6 and provided with port means at 19' adapted by turning of the shut-off means to be placed in register with a passage 20 leading from inlet l6, and a passage 2| leading to a chamber 22. The gas cock or other shut-off means 18 is closed by turning it to position in which port means I9 is out of register with passages 20 and 2 I.

It is to be understood that any other desired type of valve means may be employed in lieu of the gas cook I8, for example a remotely controlled solenoid or motorized valve. In such case the valve may be of other than the tapered plug form selected for illustration and the form of its cooperating seat may vary accordingly.

Internally the valve body part l5 has a generally L-shaped chamber 23 having a laterally extending part disposed between the chamber 22 and a chamber 29. A port 24 is adapted to place chamber 22 in communication with chamber 23. A valve seat surrounds the end of port 24 adjacent to chamber 22 for cooperation with the main thermoelectric shutoff valve 25. An outlet 21, from chamber 23, is adapted for connection with a pipe or tube 28 for supplying fuel to pilot burner l. The outlet IT, for supplying fuel to the main burner I, opens from the chamber 29 which is adapted to communicate with chamber 23 through a port 30. A valve seat surrounds the endof port 30 adjacent to chamber 29 for cooperation with a valve 3|.

A chamber 32 has an outlet 33 adapted for connection with a pipe or tube 34 for supplying fuel to intermediate pilot burners 8 and ID. A port 35 is adapted to place chamber 32 in communication with chamber 23. A valve seat surrounds the end of port 35 adjacent to chamber 32 for cooperation with a flow interrupter valve 36 for intermediate pilot burners 8 and ill.

The valve 25, which preferably has a gasket or yielding valve facing is carried by one end of a stem 38. The opposite end of stem 38 extends into an electromagnet and armature housing 39, and carries within housing 39 and armature 40. Valve 25 is preferably sufficiently loose on stem 38 to permit self-accommodating seating engagement with its valve seat, and armature 40 is preferably sufficiently loose on stem 38 to permit self-accommodation of the armature to the pole ends of the magnet frame 42. Magnet frame 42 is secured to a terminal bushing 43, the shank of which extends from housing 39. A sleeve 44 is shown screwed into valve body l5, and a nut 45 is shown screwed on the shank of the terminal bushing. The outer end of housing 39 may be peened over the flanged inner end of the bushing 43.

Packing 46 around stem 38 is interposed between a spring seating member and the inner end of housing 39. A coiled compression spring 4'! for seating valve 25 against its seat is interposed between valve 25 and the spring seating member.

In the illustrated embodiment of the invention a thermocouple, indicated at 50, is positioned so that the hot junction 5| thereof will be heated by the pilot burner flame 52 as long as the pilot burner 1 is burning. The thermocouple and leads therefor selected for illustration may be similar to the thermocouple and leads more fully disclosed in Oscar J. Leins Patent No. 2,126,564, patented August 9, 1938, or the thermocouple or thermoelectric generator and leads may be of any other suitable or preferred form, for example in the form of a thermopile with connected leads.

For the purpose of the present description, suflice it to state that the particular thermocouple selected for illustration comprises an outer tubular metallic thermocouple element and an inner metallic thermocouple element of different thermoelectric characteristics. The inner thermocouple element is joined at one end to the outer end of the outer thermocouple element to form the thermojunction 5| which is placed in position to be heated by the pilot burner 1. An inner lead conductor 53 is joined to the inner thermocouple element to form an internal thermojunction, and an outer tubular lead conductor 54 surrounds the inner lead conductor and is connected to the outer thermocouple element, for example, through a sleeve to form a third thermojunction. The inner lead conductor is insulated from the outer lead conductor, for example, by a wrapping of insulation on the inner lead conductor.

A quick detachable or removable connection is preferably provided between the electromagnet, which includes the magnet frame 42, and the ends of thhe leads 53 and 54 opposite the ends which are connected to the thermocouple elements. To this end the terminal tip 55 has a conical depression in its outer end, and a connector or terminal cone (not shown) on the end of the conductor 53 is adapted to be detachably clamped in contact therewith by a sleeve (not shown) screwed into the outer end of the bushing 43. The adjacent end of the outer tubular lead conductor 54 is connected in circuit with one side of the coil 56 which surrounds the legs of the magnet frame 42, for example, through the bushing 43. The other side of the coil 56 is connected in circuit with the inner lead conductor 53 through the terminal tip 66. As already pointed out, the use of other forms of thermocouples or thermopiles iscontemplated within the scope of the present invention. r

In the illustrated embodiment of the invention, the valve 36, which preferably has a gasket or yielding valve facing, is carried by a stem 33' which has limited sliding movement through valve 36 as will presently appear. The opposite end of stem 38' extends into an electromagnet and armature housing 33', and carries within housing 39' an armature 66'. magnet frame 42', terminal bushing 63', sleeve 44', nut 45', packing l6, coiled compression spring 41', and coil 56' surrounding one leg (or both legs) of magnet 42' are similar to like parts associated with the main thermoelectric shut-oil valve 26, as previously described.

A thermocouple 66 is positioned in juxtaposition to the constantly burning pilot burner 2 so that its hot junction will be heated by this pilot burner when it is ignited. A second thermocouple 6| is positioned in juxtaposition to the intermediate pilot burner =3 so that its hot junction will be heated by this pilot burner when it is'ignited. For purposes of illustration, the thermocouples 6D and 6| are shown of construction like the construction of the thermocouple 56. It is to be understood, however, that any other desired forms of thermoelectric generators (such as other thermocouples or thermopiles or the like) may be used within the scope of the' present invention.

The thermocouples and 6| are connected in series circuit relation with coil 56', and with each other in opposed relation, for example, with the particular form of thermocouples shown in the drawing by connecting the outer tubular thermocouple members together, for example, by conductors 62 and the contacting or connected tubular lead conductors 62'; the inner thermocouple member of the thermocouple 66 being connected, for example, by a conductor 63 to one end of coil 56 and the inner thermocouple member of the thermocouple 6| being connected, for example, by a conductor 64 to the other end of coil 56'.

In Figures 1 and 2 the terminal bushing 43' is shown threaded externally to its outer end, and a cap nut 32 screwed on the outer end of the bushing clamps the flange sleeve or member 33 in place.

It is also possible to accomplish the same result, as will hereinafter appear, by connecting the two thermocouples 60 and 6| to two coils on magnet frame 42', with the magnetic field produced by the coils arranged in opposition, as disclosed in the copending application of Russell Matthews, Serial No. 742,017, filed April 1'7, 1947. The appended claims are, therefore, to be construed accordingly.

At its inner end the gas cock or other valve means l8 has an inwardly extending stem 65 which carries a cam or other suitable actuator 66. A coiled spring 61 interposed between the cam 66 and valve body I5, maintains the tapered plug part of the gas shut-off means l6 seated in its bore in valve body l5.

A lever is pivoted at 1| within chamber 23. One end of this lever I0 is formed for engagement with cam 66 and is connected pivotally and otherwise yieldingly, if desired, at 12, with the adjacent end of stem 38'. Stem 36' has a diametrical pin or other abutment I3 which is adapted to engage valve 36 and move some to open Armature 46',

position by clockwise movement of lever 10 about its pivot 1|. The opposite end of lever 10 is formed for engagement with screw 14 of valve 25, and is connected pivotally and otherwise yieldingly, if desired, at 16 with a stem 16 for valve 3|. In counterclockwise movement of lever Ill about its pivot 1| valve 3| is opened by abutment H on stem 16, and, upon movement of lever 10 in the opposite direction, valve 3| is closed yieldingly through collar or abutment l3 and coiled spring 19.

The constantly burning pilot burner 2 is supplied with fuel through a pipe or tube 82 connected at 83 with the fuel supply pipe 3 anterior of the control device 5. The intermediate pilot burner I0 is supplied with fuel through a pipe or tube 36 connected at with the tube or pipe '34 leading-to the intermediate pilot burner 8.

The operation of the embodiment of the invention selected for illustration is as follows:

Upon movement of the gas valve means l8 to open position (by turning movement in the illustrated embodiment of the invention), fuel is permitted to pass through passages 26 and 2| into chamber 22, and cam 66 swings lever I0 clockwise about its pivot 1|, opening valves 25 and 36 with valve 3| remaining closed. Cam 66 overtravels the On position, so that lever 16 is free to fall back into its original position in so far as cam 66 is concerned.

Since the electromagnet for armature 40' is energized by constantly burning pilot burner 2 and thermocouple 60, the armature 40' is held in attracted position, i. e., in close contact with magnet frame 42', and lever Ill remains temporarily in the position into which it is actuated by cam 66 with valve 36 open. In this position, valves 25 and 36 are open, and valve 3| is closed. Gas enters through passage or port 2| (from gas shut-off means l8) into chamber 22, and hence is admitted to intermediate pilot burners 8 and I0 and to pilot burner 1.

Upon opening valves 25 and 36, the intermediate pilot burner 8 is ignited by the pilot burner 2, and the unburned gas from the intermediate pilot burner I0 and pilot burner I rises in the tube 9, which is relatively cool, to permit this action. As it reaches the flame of intermediate pilot burner 8, the gas is ignited and then recedes or flashes back to light the intermediate pilot burner I0 and pilot burner I.

Thermocouple 50 will now energize its connected electromagnet, and this electromagnet will hold its armature 40 and the valve 25 in open position. A short time later (the components may be correlated to give the desired time interval) the thermocouple 6 I, now being heated by intermediate pilot burner 8, and opposing thermocouple 60 will deenergize the electromagnet connected in circuit with thermocouples 60 and 6|. This releases armature 40', and the spring 4'! moves the valve 36 to closed position and lever 16 in a counterclockwise direction to its original position. This movement of lever I0 opens the valve 3|, whereupon gas passes to the main burner I through the outlet l1 and the fuel supply line 3 which is connected to this outlet. The

' gas at the main burner is ignited by the pilot burner I. The closing of valve 36, as above described, shuts oil the supply of gas to the intermediate pilot burners 8 and I0. 6

In case the pilot burner I should be extinguished, the thermocouple 56 will cool off and deenergize the electromagnet connected in circuit therewith, thereby releasing the armature 40 and 7 closing the valve 25 so that all gas supply to the burner I and pilot burners is shutofi.

The circuit diagram (Figure 3) shows diagrammatically the thermocouples 60 and GI, the magnet frame 42' and coil 56', and the circuit connections therefor according to Figure 1.

Figure 4 shows fragmentarily an arrangement which will permit grounding of the thermocouple connectors which are not shown but may be of the type having a first terminal connected in circuit with the inner thermocouple member, for example, through an inner lead conductor, and a second terminal insulated from the first terminal and connected in circuit with the outer thermocouple member, for example, through an outer tubular lead conductor.

These thermocouple connectors are adapted to be screwed into internally threaded openings 94 in a cooperating member 95 clamped in place on valve body part 96 by a cap nut 91. A pair of terminal tips 98 are mounted in member 95 and insulated therefrom, and these terminal tips are connected by conductors 99 to the opposite ends of coil I90 which correspond with coil 56' as shown in Figures 1 and 2. When the thermocouple connectors (not shown) are screwed into openings 94, the terminals in circuit with the inner thermocouple members contact terminal tips 98 and complete the circuit to coil I09 therethrough, and the-terminals in circuit with the outer thermocouple members are connected by grounding to member 95. The magnet frame is shown at IOI and the armature at H13 in Figure 3.

It is to be understood that a heat responsive switch or a temperature responsive element of the type shown and described in my copending application Serial No. 738,412, filed March 31, 1947, may be employed instead of the opposing thermocouples shown and described.

I contemplate arranging, the cam or actuator 66 so as to lift the lever when the gas cock or valve means [8 is being closed. This would open the ports to the pilot burners, but no gas can flow since the gas cock is closed. When new the gas cock is opened the lever will remain in raised position since magnet 42' is energized by the constantly burning pilot burner, but is free to fall, since the cam or actuator is removed from beneath the adjacent end of the lever 19 by opening of the gas cock.

Many other combinations are contemplated within the scope of the present invention. Therefore the embodiments of the invention shown in the drawing are for illustrative purposes only, and it is to be expressly understood that the drawing 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 burner in proximity to said burner for lighting same, third pilot burner means 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, valve means. to open and close said fuel supply line, a first valve member on the outlet side of said valve means and having a closed position shutting off the supply of fuel to said burner and said second and third pilot burners and an open position ."or supplying fuel for said burner and said second and third pilot-burners. a second valve member on the outlet side of said first valve member and having an open position for supply of fuel to said third pilot burner means and closed position shutting off t're supply of fuel to said third pilot burner means, a third valve member on the outlet side of said first valve member and having an open position for supply of fuel to the main burner and closed position shutting off the supply of fuel to the main burner, means for opening said first and second valve members by the operation of said valve means to open position while permitting said third valve member to remain closed, and means responsive to the heat of said third pilot burner for operating said second valve member to closed position and said third valve member to open position.

2. Apparatus according to claim 1 wherein said valve means comprises a rotatable fuel cock having a cam rotatable therewith and the means for opening said first and second valve members by the operation of said valve means comprises a pivoted lever cooperating with said cam and with said first valve member and operatively connected with said second valve member. a

3. Apparatus according to claim 1 wherein said valve means comprises a rotatable fuel cock having acam rotatable therewith and the means for opening said first and second valve members by the operation of said valve means comprises a pivoted lever cooperating with said cam and with said first valve member and operatively connected with said second valve member, said pivoted lever also having operative connection with said third valve member whereby to close said third valve member in opening said first and second valve members.

4. Apparatus according to claim 1 wherein there is a first thermoelectric generator in position to be subject to'the heat of said first pilot burner and an electromagnet connected'in circuit therewith for holding said second valve member in open position, and a second thermoelectric generator in position to be subject to the heat of said third pilot burner means and connected in circuit with said electromagnet in opposition to said first thermoelectric generator whereby to deenergize said electromagnet and release said second valve member for movement to closed position upon ignition of said third pilot burner means.

5. Apparatus according to claim lwherein there is a first thermoelectric generator in positiontobe subject to the heat of said first pilot burner and an electromagnet connected in circuit therewith for holding said second valve member in open position, and a second thermoelectric generator in position to be subject to the heat of said third pilot burner means and connected in circuit with said electromagnet in opposition to said first thermoelectric generator whereby to deenergize said electromagnet and release said second valve member for movement to closed position upon ignition of said third pilot burner means, said third valve member being operatively connected with the means for opening said first and second valve members whereby to open said third valve member in operation of said second valve member to closed position.

6. Apparatus according to claim 1 wherein there is a thermoelectric generator in position to be subject to the heat of said second pilot burner and an electromagnet connected in circuit with said thermoelectric generator for holding said first valve member in open position.

7. In apparatus of the class described, in combination a first constantly burning pilot burner, second on and off pilot burner means positioned to be ignited by said first pilot burner, a valve member having an open position for supply of fuel to said second pilot burner means and closed position shutting oil the supply of fuel to said second pilot burner means, means for operating said valve means to open position, a first thermoelectric generator in position to be subject to the heat of said first burner, an electromagnet connected in circuit with said first thermoelectric generator for holding said valve member in open position, and a second thermoelectric generator in position to be subject to the heat of said second pilot burner and connected in circuit with said electromagnet in opposition to said first thermoelectric generator whereby to deenergize said electromagnet and release said valve member for movement to closed position upon ignition of said second pilot burner.

8. In a control device of the class described, in combination, a valve body having a first chamber provided with a main inlet, a second chamber provided with an auxiliary outlet, and a third chamber provided with a main outlet, an intermediate chamber between said first chamber and said second and third chambers, said intermediate chamber having an auxiliary outlet; also outlets leading to said second and third chambers and an inlet leading from said first chamber, first and second valve members to open and close communication between said intermediate chamber and said second and third chambers, a third valve member to open and close communication between said first chamber and said intermediate chamber, valve means to open and close the inlet to said first chamber, and means for opening said first valve member, said means for opening said first valve member also operating to close said second valve member and to open said third valve member by the operation of said valve means to open the inlet to said first chamber.

9. A device according to claim 8 wherein the means for opening said first valve member and closing said second valve member by the operation of the valve means to open the inlet to said first chamber has operative connection to open said second valve member upon operation of said first valve member to closed position.

10. A device according to claim 8 wherein there is a thermoelectric generator and an electromagnet connected in circuit with said thermoelectric generator for holding said first valve member in open position.

11. A device according to claim 8 wherein there is a first thermoelectric generator and an electromagnet connected in circuit with said first thermoelectric generator for holding said first valve member in open position, and a second thermoelectric generator connected in circuit with said electromagnet in opposition to said first thermoelectric generator whereby to release said first valve member for movement to closed position by the energization of said secon thermoelectric generator.

12. A device according to claim 8 wherein said valve means comprises a rotatable fuel cock having a cam rotatable therewith and the means for opening said first valve member and closing said second valve member comprises a lever pivoted within said intermediate chamber, said lever having operative connection with said first and second valve members.

13. A device according to claim 8 wherein there is a third valve member controlling communication'between said first chamber and said intermediate chamber and wherein said third valve member is actuated to open position by the movement of the valve means which opens and closes theinlet to said first chamber.

14. 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 for igniting said burner, intermediate pilot burner means for assuring ignition of said second pilot burner from said constantly burning pilot burner, a fuel supply line for supplying fuel to said burner and said pilot burners, valve means to open and close said fuel supply line, and control means in said fuel supply line on the outlet side of said valve means and operable firstly to establish a flow of fuel to said intermediate pilot burner means and said second pilot burner, and then to establish a flow of fuel to the burner after a time delay following ignition of said second pilot burner, said control means being set into operation by the operation of said valve means to open said fuel supply line.

ERNST WITZEL.

REFERENCES CITED The following references are of record in the file of this patent: