US1725296A - Burner-lighting mechanism - Google Patents

Description

Aug. 20, 1929. A. E. PAIGE 1,725,296

BURNER LIGHTING MECHANISM Filed Aug. 31, 1925 2 Sheets-Sheet 1 .54 35 FIG] 2 1 o o o 7] L f f I: i2 Q in 72 V. I I.

//V Vf/V TOR:

Patented Aug. 20, 1929.

UNITED STATES PATENT OFFICE.

Application filed August 31', 1925. Serial No. 53,530.

My invention relates 'to electric igniting means particularly adapted for gas burners of the Bunsen type used in stoves, water heaters etc., for instance, in heaters of the type claimed in application Serial No. 752,037 filed November 24, 1924, by Victor Mauck; wherein the supply of gas is thermostatically controlled to maintain the sameat the minimum required under all circumstances to maintain a store of water at a predetermined temperature. In such heaters, the gas consumption may be reduced to such a degree that the flames are scarcely perceptible at the burner orifices and, consequently, may be extinguished by comparatively slight fluctuations in the pressure of the gas supplied; or the air draft incident to opening a door for lighting the same.

Therefore, it is the object and effect of my invention to provide an igniting device capable of lighting such burners automatically whenever the gas is turned on and of relighting them whenever the burner flames are extinguished from any cause, while the gas continues to flow through the burner.

The several forms of my invention hereinafter described each include the combination with a gas burner; of an ignitingelement, conveniently a coil of resistance wire, extending above the burner orifices, and mounted upon an insulating base; one terminal of said coil on said base forming part of a thermostatic switch of which the movable element is a disk formed of two metals having respectively different coeflicients of expansion; said disk being arranged to be plane at a criticaltemperature and to snap to convex form, in respectively opposite directions at temperatures'above and below said critical temperature; said coil terminal being arranged to contact with said disk in its cooler convex form to thus maintain the igniting circuit closed at said thermostatic switch in the absence of the normal heat from said burner. Such thermostatically controlled igniter unit is preferably included in the lighting circuit with a manually operative switch cooperatively connected with the valve controlling the supply of gas to the burner; in such manner that the circuit is closed at said valve switch whenever gas is turned on, and the circuit is broken at said valve switch whenever the gas is shut off at said valve Therefore, in that combination, the ignlter element is only energized plied thereto,

if and when the gas is turned on and consumed; the circuit at the thermostatic switch being broken by distortion'of said disk by the heat of combustion of the gas.

My invention includes the various novel features of construction and arrangement hereinafter more definitely specified.

In said drawings;'Fig. I is a fragmentary plan view of a gas burner having a convenient embodiment of the igniter elements of my invention applied thereto.

Fig. II is a fragmentary sectional View of said burner and the elements of the igniting mechanism appurtenant thereto, taken on the line II, II in Fig. I. I

Fig. III is a fragmentary sectional View of said burner and'appurtenances taken on the line III, III in Fig. I.

Fig. IV is adiametrical sectional view of the thermostatic disk shown in Figs. II and III, but with the spring thereof released and normally distended.

ig. is a plan view of said disk shown in Fig. IV, showing its central contact spring formed in unitary relation therewith.

Fig. VI is an inverted plan View of the insulating base for the igniter coil and its terminals shown in Figs. I, II, and III.

Fig. VII is an elevation of a convenient form of valve arranged to control the supply of gas to the burner shown in Fig. I and including the gas jet tube, of which a fragment is indicated at the right hand side of Fig. I; said valve being coordinately connected with an electric switch.

Fig. VIII is a plan View of a burner, such as shown in Fig. I, but with a modified form of the igniter elements of my invention apand including an elevation of the right hand side of said gas valve and valve switch shown in Fig. VII; with a diagrammatic indication of the electric igniter circuit including said elements in connection with an electric generator.

Fig. IX is a fragmentary sectional view of the burner and the igniter elements appurtenant thereto, taken on the line IX, IX in Fig. VIII.

Fig. X is a fragmentary sectional View, similar to Figs. II and IX, but showing a modified form of igniter elements.

Fig. XI is a sectional view, similar to Fig. III, showing a thermostatic switch and igniter elements such as indicated in Figs. I to VI inclusive; but with the thermostatic latter and adjustable.

In the form of my invention shown in- Figs. I to VI lnclusive; the gas burner comprises an arcuate tubular member 1 having jet orifices 2 in the upper wall thereof and in unitary relation with the mixing tube 3 which has the air inlet 4 at the bottomtheicof and the gas inlet 5 at the right hand end thereof in which the gas supply jet tube 6, shown in d'etailsin Figs. VII and VIII is inserted in telescopic relation. Said gas burner has the thermostatic switch casing 8 conveniently cast in unitary relation therewith, as shown in Figs. II and III and including the recessed seat 9 for the thermostatic disk 10. As above contemplated; said disk 10 is formed of two metals having respectively different coefiicients of expansion and at atmospheric temperatures is of the spherical curvature shown in full lines in Figs. II, III and IV ;-the metal forming the lower face of said disk having a greater coefficient of expansion under increment of heat than the metal forming the upper face of said disk. Consequently, said disk is arranged to be plane at a critical temperature, which is above that of the atmosphere, but to snap to convex form, in respectively opposite directions, at temperatures above and below said critical temperature. That is to say; if heated above its critical temperature, it snaps to the reverse convex form shown in dotted lines in Fig. IV but, upon being cooled to said critical temperature, it first returns to plane form and, thereupon, snaps to the convex form shown in full lines in Figs. II, III and IV; hereinafter referred to as the cooler convex form of said disk.

As shown in Figs. II and III; said disk 10 is presented in opposition to the screw 11 which is in coaxial relation therewith but mounted in the insulating base 12 which is conveniently provided with the arcuate rib 13 by which. it is centered in said switch casing 8. Said screw 11 may be adjusted axially toward and away from said disk 10 through the nut 14 which is seated in'the recess 15 in said base 12, and thus prevented from rotating. Said screw 11 may be jammed in adjusted position, by the nut 16 exterior to said base 12 which also serves to clamp one end of the resistance wire 17 (which extends from one end of the igniter coil 18) in electrical connection with said screw 11 and consequently in electrical connection with said disk 10, when the latter is in the cooler convex position shown in Fig. II. I preferto provide means to prevent said disk from accidentally turning on its seat 9 in said casing'8 to avoid modification of the adjustment aforesaid and such means may conveniently include the pin 19 driven into a drilled hole in said casing 8 and fitting in the marginal notch 20 of said disk, as indicated in Fig. V. If said disk 10 were merely of theconvex form indicated in Figs. II and III; heating the same would shift it out of contact with said screw 11, in its passage to plane form, so slowly that there would be sparking and consequent erosion of both of said elements at the gap between them. Therefore, I prefer to provide a spring which will maintain electrical connection between said disk 10 and screw 11 until said disk reaches its plane form, from which it will instantly snap to its opposite convex form as above described, and such a spring is conveniently formed by punching the center of the disk in helical form, as best shown in Figs. IV and V; said spring 22 having such resilience as to normally present itself in the position shown in Fig. IV by being compressed to the configuration of the remainder of said disk 10 when the screw 11. is in the adjusted position shown in Figs. II and III.

As shown; the wire 17 of said ignited coil 18 extends through the notch 23 in the ridge 24 on said base 12; which ridge also has the notch 26 for the other end wire 27 of said coil which extends beneath the nut 28 on the binding screw 29 which is held in the position shown in Fig. III by engagement with the nut 30 which is seated in the recess 31 in said base 12, and thus prevented from rotating. Said nut 28 also holds in electrical connection with said coil 18, the conductor 3a forming one side of the igniting circuit, of which the opposite side includes said burner with which the thermostatic disk 10 in electrical contact, as shown in'Figs. II and III, and above described. As diagrammat icaily indicated in Fig. I; such circuit includes the source of electric energy and the manually operative switch 36, one terminal of the latter being grounded upon said burner as indicatedby the line 37, convcniently by way of the hereinafter described.

The switch, diagrammatically indicated at 36 in Fig. I, is preferably constructed and arranged as shown in Figs. VII and VIII, wherein it is appurtenant to the valve which controls the supply of gas to the burner through said jet tube 6, and so arranged that the circuit is closed at said valve switch 36 when the gas is turned on, and broken at said switch when the gas is shut off, in the position shown in Figs. VII and VIII. In said figures; said gas jet tube 6 is in unitary relation with the valve casing 38 wherein the gas pipe fittings, as

valve plug 39 is mounted to rotate and proand 59 of insulating material;

As best shown in ment of said valve 39 is limited to 90 b the pin 41 which encounters the opposite en of the slot 42 in said valve casing. Said pin 41 also conveniently forms one terminal for said switch marked 36 which, in Figs. VII and VIII, is a spring conveniently formed of sheet metal secured upon the insulating base 43 by the binding screw 45 and nut 46 and prevented from turning on said base by its flanges 47 which overhang the edges of said base. Said binding screw 46 also serves to hold, in electrical connection with said valve switch 36, the electrical conductor 34 which is connected to said generator 35. As shown in Fig. VIII; said insulating base 43 is. conveniently secured to said valve casing 38 by screws 49 and 50.

I find it convenient to mold said insulating base 12-of refractory ceramic material to resist the heat to which it is subjected by its proximit to the gas flames at the burner orifices 2. I Iowever, an insulating support for the igniter coil 18 may be otherwise con-. structed and arranged. For instance, as shown in Figs. VIII and IX; said coil 18 is mounted upon a plate of mica 52 which is rigidly clamped in insulated relation with the metallic base member 53 having the an nular rib 54 fitted in said switch casing 8. Fig. IX; the clamping means include the insulating bushing 55 which has an annular shoulder bearing upon the under side of said base 53 and extends through the latter and through the mica plate 52 and the several washers 57, 58 all of said insulating material being secured by the binding screw 60 which is in threaded engagement with the outer end of said bushing" 55 and binds the end of said conductor 34 and the end of the coil wire 27, in electrical contact. As shown in Figs. VIII and IX; the opposite end wire 17 of said igniter coil 18 eXtends't-hrough said mica plate 52 and the notch 62 in said insulating washer 58 and through the insulating sleeve 63 and is secured. beneath the binding screw 64 which is also in threaded engagement with said bushing 55 and in axial relation with the thermostatic disk 10.

s shown in Fig. X; a single piece of bakelite or other similar insulating material 67, having metallicnuts 68 and 69 imb'edded therein for engagement with said screws 60 and 64, may be substituted for the metallic ba'se wit-h the separable insulating elements shown in Fig. IX; said mica plate 52 resting upon the top of said base 67 and the end wire 17 of the igniter coil 18 extending through the passageway 69 in said base, as shown in Fig. X i

It is to be understood that either of said bases 12, 53,- or 67 may be detachably rigidly secured in connection with said burner 1 by means of screws 71 and 72 which are in threaded engagement with the metal of said burner. It may be observed that although the formation of said bases 12 and 67 of molded insulating material is economical;

they are frangible, whereas, the construction shown in Fig.

IX, including the metal base 53, is not only more rugged, but permits said screws 71 and 72 to be soldered in connection therewith, to prevent their accidental displacement and, as indicated in Figs. IX and X, the end wires 17 and 27 of the igniter coil may be soldered respectively at 73 and 74 to the binding screws 60 and 64 by which they are held; so that those screws shall not be accidentally loosened.

Although I find it convenient to utilize a portion of the gas burner to form the easing 8 for the thermostatic switch, as above described; it is to be understood that a suitable casing may be otherwise constructed and arranged. For instance, as shown in Fig. XI, a thermostatic switch and igniter coil unit such as shown in Figs. I to VI inclusive, may be mounted in the casing 76, entirely independent of the burner but which may be attached thereto in any convenient manner or be otherwise located where it is subjected to the heat of combustion of the gas from the burner, when the latter is in operation. It is to be understood that the source of electric energy indicated at 35 in Figs. I and VIII may be an electric generator in a municipal supply circuit to which the conductors 34 are electrically connected by way of an ordinary plug and socket; but the source of electric energy required for the ignition circuit may be local to the latter; for instance, a secondary or primary battery ma be included in said circuit at 7 8 in Fig. VIII. However, the operation of each form of my invention above described is as follows:

The needle valve 79, which is screw threaded at its outer end and has the screw driver slot 81, is axially adjusted with respect to the jet orifice 82 in the screw plug 83 at the inner end of said gas supply jet tube 6, to limit the supply of gas to the burner to the minimum amount required; independently of said valve 39. The screw end 80 of said needle valve 79 is coveredand concealed by the screw cap 84 which is in en agement in Figs.

open said port for the admission of gas to the burner; such motion brings the valve switch member 41 into contact with its opposing member 36 to close the circuit thereat and energize the igniter coil 18 to light the gas issuing from the burner orifices 2. The heat of combustion of the gas then distorts said thermostatic disk 10, toward its plane form, from which it snaps into concave form, the reverse of that shown in' Figs. II, III, IX, X and XI, and indicated in dotted lines in Fig. IV; to break the circuit at the thermostatic switch; so that the electrlc energy is not wasted.

The igniting circuit remains broken at said thermostatic switch, as long as the normal heat of combustion of the burner causes said thermostatic disk 10 to retain such inverted convex form, indicated in dotted lines in Fig. IV. However, if and when such heat fails; said disk 10 immediately cools to its 4 Fig. XII, the spring contact 89 for the the-g mostatic disk 90 is independent of the latter critical temperature and plane form and instantly snaps therefrom to the cooler convex form shown in full lines throughout the drawings. Of course, if such loss of heat is due to the fact that the supply of gas has been shut off by manual operation of the valve 39; the igniting circuit is broken at the gap between the valve switch elements ,36, {1:1, as shown in Fig. VIII, and the igniter coil 18 is not energized by the restoration of said thermostatic disk 10 to the upwardly curved position shown. However, if the failure of heat is due to accidental exti11-' guishment of the'burner flames, while the gas remains turned on; then 'the circuit 1s closed and the burner igniter 18 energized by the automatic snap action of said disk 10 incident to such loss of heat therefrom, and such action of my device is automatically continuous to continuously maintain combustion of the gas as long as the latter is permitted to flow throughthe burner and thus avoid Waste of gas and the dangers incident to the escape of unconsumed gas from the burner.

As above noted; the'provision of a spring electrical connection for the thermostatic disk avoids sparking and erosion by. maintaining the circuit closed at the thermostatic disk until said disk has reached the form in which it will instantly snap to break the circuit and, although I find, it convenient to form aspring, as 22, in unitary relation with the disk; it may be otherwise constructed and arranged. For instance, as shown in T and adjustable by means .of the screw 91.

Axial adjustment ofthe screw terminal 11 shown in Figs. II, III, and XI, and of said screw 91 to determine the temperature at which the electric circuit is closed at said thermostatic switch; which temperature may Therefore, I do not desire to limit myself to the precise details of construction and arrangement herein set forth, as it is obvious that various modifications may be made therein without departing from the essential features of my invention, as defined in the appended claims.

I claim:

1. A thermostatically operative electric switch including a circular casin having an axial terminal; a disk, in said casing, formed of two metals having respectively different coeflicients of expansion; said disk arranged to be plane at acritical temperature, but to snap to convex form, in respectively opposite directions at temperatures above and below said critical temperature; and a spring, independent of said terminal, and extending from one face of said disk, ar-

ranged to maintain said disk in contact with said terminal, when said disk is convexed toward said terminal, and until it reaches said critical temperature and plane form, and snaps to the oppositely convex form; whereby, the electric circuit is then instantly broken at said terminal.

2. A thermostatically operative electric perature" and plane form, and snaps to the oppositely convex form; whereb the electr1c circuit is then instantly bro en at said terminal.

2 In a thermostatically operative electric switch; the combination with an electric terminal; of a disk formed of two metals having respectively different coeflicients of cxpension; said disk arranged to be plane at a critical temperature, but 'to snap to convex form, in respectively opposite directions at temperatures above and below said critical temperature; and a spring, independent of said terminal," and extending from one 'face of said disk, arranged to maintain said disk in contact with said terminal, when saiddisk is convexed toward said terminal, until it snaps to the oppositelyconvex form; whereby, the electric circuit is then instantly broken at said terminal.

4. A thermostatic element comprising a disk formed of two metals having respec- I said disk arranged to be plane at a critical temperature, but to snap to convex form, in respectively opposite -directions at temperatures above and below said critical temperature; said disk bein punched to form a spring normally extending from one face thereof beyond its range of such snapping movement.

6. In a thermostatically operative electric switch; the combination with an electric terminal; of a disk formed of two metals having respectivel at a critical temperature, but to snap to convex form, in respectively opposite directions at temperatures above and below said critical temperature; and a spring, independent 30 of said terminal, and arranged to maintain said disk in contact with said terminal, when said disk is convexed toward said terminal, until it snaps to the oppositely convex form;

whereby, the electric circuit is then instantly 5 broken at said terminal.

In testimony whereof, I have hereunto signed my name at Philadelphia, Pennsylvania, this twenty-ninth day of August, 1925.

ARTHUR E; PAIGE.

CERTIFICATE OF CORRECTION.

Patent No. l, 725, 296.

ARTHUR a PAiGE.

Granted August 20, 1929, to

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, lines and '57, for the word "consumed'f read "unconsumed"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the'PatentfOffiee.

Signed and sealed this 10th day of September, A. D, 1929. I

(Seal) M. J. Moore,

Acting Commissioner of Patents.

different coefiicients of 25 expansion; said disk arranged to be plane

Images