US3926172A

US3926172A - Electric igniter for gas burners

Info

Publication number: US3926172A
Application number: US518440A
Authority: US
Inventors: Domenick Saponara
Original assignee: Raytheon Co
Current assignee: Raytheon Co
Priority date: 1974-10-29
Filing date: 1974-10-29
Publication date: 1975-12-16
Anticipated expiration: 1992-12-16

Abstract

An electric igniter for gas burners or the like comprising a ceramic cylinder having a longitudinal bore containing an insulated wire adapted to be connected to a suitable source of electrical potential, and securing means connected to and retaining the wire within the bore, one end of the wire and/or the securing means being exposed to an adjacent grounding element whereby a spark may be generated therebetween.

Description

O Unlted States Patent 1 1 1 1 3,926,172 Saponara Dec. 16, 1975 [5 1 ELECTRIC IGNITER FOR GAS BURNERS 3,180,418 4/1965 MacLeod 313/232 x Inventor: Domenick S p nara, Ma ung e, Pa 3,322,989 5/1967 Klem 317/96 X Assigneel Raytheon p y, Lexington, Primary E.\'aminerEdward G. Favors Mass. Attorney, Agent, or FirmHarold A. Murphy; Joseph [22] Filed: Oct 29, 1974 D. Pannone; John T. Meaney 21 A LN .1518 4 l 1 pp 0 ,4 0 57 ABSTRACT [52] U S Cl 126/39 E. 313/141 431/264 An electric igniter for gas burners or the like compris- [51] Int Cl .2 u F24C 3/10 ing a ceramic cylinder having a longitudinal bore con- [58] Fie'ld 29/25 12 taining an insulated wire adapted to be connected to a i 1 126/59 suitable source of electrical potential, and securing means connected to and retaining the wire within the [56] References Cited bore, one end of the wire and/or the securing means 7 being exposed to an adjacent grounding element UNITED STATES PATENTS whereby a spark may be generated therebetween.

2,896,704 7/1969 Aleweld 1. 126/39 E 3,048,433 8/l962 Doetsch 313/332 21 Clalms, 9 Drawing Figures US. Patent Dec. 16, 1975 SheetlofZ 3,926,172

J U W US. Patent Dec. 16, 1975 Sheet20f2 3,926,172

ELECTRIC IGNITER FOR GAS BURNERS BACKGROUND OF THE INVENTION It is becoming common practice to use electric igniters to ignite top burners of gas ranges, particularly since concentrated effort is being exerted to reduce energy consumption and pollution which are concomitant with constantly burning gas pilots.

Some approaches to manufacture of electric igniters have been found to be relatively complicated and, therefore, expensive. This is highly undesirable in a competitive market such as exists in the home appliance field. Such prior art igniter structures, for exam ple, often require two separate electrode leads with respective separate terminals and brackets. In some prior single wire electrode structures, a separate tenninal structure is also required. In still other prior art igniters, separate grounding blades are employed which must be precisely positioned positively with respect to the electrode, and again a separate terminal is required.

SUMMARY OF THE INVENTION The foregoing and other objections to and disadvantages of the prior art are overcome in the present invention by a simple, uncomplicated and relatively inexpensive igniter structure wherein there is provided a dielectric electrode support having a bore therethrough for receiving a conventional insulated wire, one end of which terminates adjacent an exterior surface of the support. The end of the wire is held firmly in place by novel securing means which may comprise a screwlike member inserted into the exposed end of the wire or an encircling tubular clip member which is forcibly inserted into the bore.

A grounding element is mounted over and spaced from the adjacent end of the wire or securing member so as to provide a spark gap therebetween. In the case where the screwlike member is used as the securing means, the member becomes the effective electrode. Where the tubular clip is used as the securing means, the exposed end of the wire is the effective electrode. In still another embodiment, the tubular clip may be closed at its outer end and the wire is made to have contact with the inner surface of the clip so that, again, the clip performs not only its securing function, but also becomes the effective electrode.

In any event, according to this invention, the wire is retained within the bore in the support by securing means which may itself become the effective electrode or may so support the wire that the end of the wire becomes the effective electrode.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objectives of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein;

FIG. 1 is a top plan view of an electric igniter shown in cooperative relationship with a pair of gas burners;

FIG. 2 is an elevational view of the structure shown in FIG. 1;

FIG. 3 is a sectional view taken substantially on line 33 of FIG. 2 looking in the direction of the arrows;

FIG. 4 is an enlarged fragmentary axial sectional view of a preferred form of the electrode structure;

FIG. 5 is an axial sectional view of a second embodiment of the electrode structure;

FIG. 6 is an enlarged fragmentary axial sectional view of substantially the electrode structure shown in FIG. 5;

FIG. 7 isa plan view of the structure shown in FIG. 5;

FIG. 8 is a fragmentary axial sectional view showing another embodiment of the electrode structure; and

FIG. 9 is a diagram of a schematic circuit for operating the electric igniter of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more particularly to the following description, taken in connection with the accompanying drawings wherein like characters of reference designate like parts throughout the several views, one preferred em bodiment of the invention is shown in FIGS. 14 and comprises the igniter referred to generally by numeral 10.

The igniter 10, to be described below in detail, is mounted in a suitable location such as by a bracket 12 bolted or otherwise fixed to the burner box bottom 14 of a gas range, for example. igniter 10, in the particular structure shown, is positioned between two spaced gas burners 16 with flash tubes 18 extending between the igniter l0 and respective burners as shown in FIGS. 1 and 2.

Each burner comprises a burner head 20 which is connected by well known means to a source of fuel gas so that upon manipulation of suitable control means (not shown) gas will flow into the interior of a burner head for ignition. The burners heads are provided with a number of upper ports (not shown) around their upper peripheries at which the conventional blue flame is produced when the gas is ignited. Such burner construction and gas controls therefor are disclosed in detail in US Pat. No. 3,799,730, to which patent reference may be made for a more detailed description of parts and devices which do not in themselves constitute parts of the present invention.

Additional ports 22 are provided near the base of each burner head 20 opposite the adjacent end of a respective flash tube 18. Thus, gas will escape from the burner head through ports 22 and will flow, by reason of normal gas pressure, through the adjacent flash tube 18, to the igniter 10 where it will become ignited and will flash back to the burner head whereupon the gas at the upper ports will become ignited.

The flash tubes 18 are each mounted on a support 26 which may be formed, for example, by striking or punching out portions of a pair of brackets 28. One end of a bracket 28 is fixed to a respective burner head 20 at the outer end. The other ends of the brackets 28 are bifurcated to form two

separate arms

30 and 30a, each arm having a downwardly projecting tab 32 which interfits within a respective locating aperture 34 provided therefor in the top of the igniter support bracket 12. Small bolts 36 or other suitable means are provided for securing the arms to the bracket 12, thus retaining each of the assembled bracket, flash tube and burner units in a precise location with respect to the igniter 10.

The igniter 10 shown in FIGS. l-4 comprises a substantially cylindrical insulator 38, preferably of ceramic which is vertically mounted within an aperture in the top of the bracket 12. Any suitable means may be provided for retaining the insulator in position such as, for example, making the lower portion of the cylinder of reduced diameter to provide a circumferential ledge 40 (FIG. 4) which rests upon the upper surface of the bracket 12, and providing a circumferential groove 42 3 therearound in which may be located a spring clip 44 engaging the under side of the bracket 12 to hold the insulator in place as shown in FIG. 3.

Extending longitudinally of the insulator 38 is a bore 46 (FIG. 4) within which is positioned one end portion of an electrode lead 48 including a wire 50 which is provided with the usual flexible rubber, plastic, fabric or other insulating cover 52. The lead 48 may be any suitable electrical conductor such as will conduct, for example, 25 KV DC at temperatures of as much as 250C, for example.

The lead 48 is held in place within the bore 46 by means of a securing member 54 which in this embodiment of the invention comprises a screw which is preferably a No. 4 nickel plated sheet metal tapping screw one-half inch long, flat head style so as to be substantially flush with the upper end surface of the insulator 54 when assembled therewith. As shown in FIG. 4, the screw 54 is threaded into the upper exposed end of the lead 48, the threads thereof actually cutting their way directly into the end of the wire 50. This of course causes consequent expansion of the engaged portion of the wire 48 and compression of the covering 52 between the wire and the wall of the bore 46, as shown, thus firmly retaining the lead in place. The extreme upper end of the bore 46 may be chamferred to receive the head of the screw 54 so that the exposed surface of the screw head is flush with the adjacent surface of the insulator 38.

The screw 54 thus is the active electrode and, therefore, there must be positive electrical continuity between the screw and wire 50 so that in operation of the device, as will be described hereinafter, a spark will be generated between the head of the screw and an adjacent electrode member such as grounding bar 56. Bar 56 is conveniently an inverted U-shaped metal member having two legs 58 connected by a bight portion 60. Legs 58 extend downwardly through openings provided therefor in the top of bracket 12 on either side of insulator 38, as shown in FIG.' 3, and the extreme ends of the legs may be angled beneath the bracket top as shown to prevent inadvertent or accidental removal of the shorting bar 56 from the bracket 12.

The bight portion 60 of bar 56 is provided with a dimple 62 which projects slightly downwardly from its under side toward screw 54. Thus there is provided a suitable gap between the screw and bar as will permit production of a satisfactory spark when the device is used.

Although the electrical circuit for creating a spark across the gap between the screw member 54 and bar 56 may be of any selected well known type, one suitable schematic circuit is shown in FIG. 9 wherein one side of a high voltage transformer 64 is connected to a source of alternating current through a switch 66. Switch 66 may be embodied in a manually operable knob structure whereby when the knob is rotated slightly to open a gas valve (not shown) it will simultaneously close the contacts on switch 66, causing current to flow to the transformer 64. The opposite side of the transformer has one tap connected to ground while the other tap is connected to electrode lead 48. Thus, since the lead 48 is electrically connected to the effective electrode screw member 54 and the grounding bar 56 is grounded, a spark will be generated across the gap between the screw member 54 and the bar 56. This spark will continue 'to be produced until ignition is achieved at which time the knob will be rotated further 4 to control the resultant flame. This will simultaneously cause the contacts of switch 66 to open, disrupting the flow of current to the igniter and spark generation will cease.

Another suitable spark igniter circuit is the ignition module, Catalog No. OO7-OO7C, sold by Lutron Electronics Co. of Emmaus, Pennsylvania which has its own built-in means for cutting off spark generation automatically after a selected time interval. Still another suitable circuit is the spark ignition system Series O5l2 sold by Fenwal, Inc. of Ashland, Massachusetts.

Referring now to FIGS. 5-7, a second embodiment of the invention comprises a dielectric insulator 68 which has an upper portion of reduced diameter extending upwardly through an aperture formed between two spaced arms 70-72 of a supporting bracket 74. This bifurcated structure is formed by striking out a portion 76 of the bracket 74, and bending the struck out portion 76 so as to have an end portion 78 overlying the adjacent upper end of the insulator 68 in spaced relation to it.

The ledge formed on the circumference of the insulator 68 between the two portions of different diameters rests adjacent the under side of the bracket 74 and is held there by a U-shaped member 80 (FIG. 6) which seats against the lower end surface of the insulator 68 and has legs 82 which extend upwardly along opposite sides of the insulator. The extreme upper ends of the legs 82 project through apertures in the bracket arms 70-72 and are bent to overlie the arms and, therefore, hold the insulator in position.

The insulator 68 is longitudinally bored to receive an electrode lead 84 comprising a wire 86 and flexible covering 88, similar to lead 48. The securing means for holding the lead in the bore comprises a tubular metal clip member 90 (FIG. 6) which closely encircles the upper end of the lead 84 and is driven firmly into closefitting engagement with the adjacent end of the bore to frictionally hold the lead in place. The inner wall of the bore may be provided with a circumferential groove 92 in which reside the ends of spring fingers 94 which are struck out of the side walls of the clip 90. This structure aids in preventing accidental or inadvertent withdrawal of the lead from the bore.

In the device shown in FIGS. 5-7 the end of the wire 86 is exposed and thus is the effective electrode, lying substantially flush with the end surface of the insulator. It will be apparent that this igniter will function in the circuit of FIG. 9 to produce a spark in the gap between the end of the wire 86 and the overlying portion 78 of bracket 74 which functions as the shorting bar.

In a further embodiment as shown in FIG. 8, the securing member which retains the lead 96 in position within the bore in insulator 98 is a tubular shell member 100 having a closed end wall 102. Lead 96 has its covering 104 peeled back slightly so that an end portion 106 of wire is exposed and free. When this end of the lead 96 is inserted fully into the shell 100, the end 106 of the wire 108 will form a wad which engages a broad inner surface area of the end wall 102 of the shell clip member.

Any suitable constrictions or the like may be utilized to retain the lead 96 in position in the shell 100 and to retain the shell in the insulator bore. The embodiment may be used in either electrode structure of FIGS. l-4 or FIGS. 5-7, and the end wall 102 of the shell clip member will function as the active electrode member of the device.

From the foregoing it will be apparent that all of the objectives of this invention have been achieved by the novel, simple, efficient and economical structure disclosed. However, it will also be apparent that various modifications and changes may be made by those skilled in the art without departing from the spirit of the invention as expressed in the accompanying claims. Therefore, all matter shown and described is to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. An electrical igniter electrode comprising an insulating support having an aperture therethrough, a lead comprising an electrically conducting wire having an end portion positioned within said aperture, and mechanical gripping means attached to said end portion of the lead for retaining said lead in said aperture, said gripping means being a threaded metal member disposed at least partially internally of and in threaded engagement with the end of the wire and in electrical contact therewith.

2. An igniter electrode as set forth in claim 1 wherein said metal member extends coaxially of said end of the wire and is embedded therein, with portions of the end of the wire encircling the metal member and wedged between the member and the surrounding wall of said aperture.

3. An igniter electrode as set forth in claim 1 wherein said wire is covered by a flexible covering, said gripping means is a screw member threaded into the end of the wire, and said covering is compressed between the wall of the aperture and the portion of the wire which encircles the screw member.

4. An igniter electrode as set forth in claim 3 wherein said screw member is inserted within the aperture to an extent where its exposed end lies substantially flush with the adjacent end of the support.

5. An electrical igniter electrode comprising an insulating support having an aperture therethrough, a lead comprising an electrically conducting wire having an end portion positioned within said aperture, and mechanical gripping means attached to said end portion of the lead for retaining said lead in said aperture, said wire being covered by a flexible covering, and said gripping means being a tubular clip interfitted tightly into said aperture between the wall of the aperture and the wire covering.

6. An igniter electrode as set forth in claim 5 wherein said clip has on its outer circumference means interfrtting with cooperative areas on the inner wall of the aperture.

7. An igniter electrode as set forth in claim 5 wherein the ends of said clip and wire are disposed substantially flush with the adjacent end of the insulator.

8. An igniter electrode as set forth in claim 5 wherein the tubular clip has a closed outer end, said covering is foreshortened to provide a projecting end portion of the wire, and said projecting end portion of the wire is wadded beneath said closed outer end of the clip and in electrical contact therewith.

9. An electrical igniter comprising a support, a dielectric member mounted on said support and having a bore therethrough, a lead comprising an electrically conductive wire having one end portion positioned within said bore, mechanical gripping means attached to said end portion of the lead for retaining said lead in said bore, a conductive member mounted on said support and having a portion overlying the adjacent end of the dielectric member in spaced relation to the end of said wire, and means for applying electrical potential to said lead for producing a spark across the gap between the end of the wire and the overlying portion of the conductive member, said gripping means being a threaded metal member disposed at least partially internally of and in threaded engagement with the end of the wire and in electrical contact therewith.

10. An electrical igniter as set forth in claim 9 wherein said metal member extends coaxially of said end of the wire and is embedded therein, with portions of the end of the wire encircling the metal member and wedged between the member and the surrounding wall of said aperture.

11. An electrical igniter as set forth in claim 9 wherein said wire is covered by a flexible covering, said gripping means is a screw member threaded into the end of the wire, and said covering is compressed between the wall of the aperture and the portion of the wire which encircles the screw member.

12. An electrical igniter as set forth in claim 11 wherein said screw member is inserted within the bore to an extent where its exposed end lies substantially flush with the adjacent end of the insulator.

13. An electrical igniter comprising a support, a dielectric member mounted on said support and having a bore therethrough, a lead comprisng an electrically conductive wire having one end portion positioned within said bore, mechanical gripping means attached to said end portion of the lead for retaining said lead in said bore, a conductive member mounted on said support and having a portion overlying the adjacent end of the dielectric member in spaced relation to the end of said wire, and means for applying electrical potential to said lead for producing a spark across the gap between the end of the wire and the overlying portion of the conductive member, said wire being covered by a flexible covering, and said gripping means being a tubular clip interfitted tightly into said aperture between the wall of the aperture and the wire covering.

14. An electrical igniter as set forth in claim 13 wherein said clip has on its outer circumference means interfitting with cooperative areas on the inner wall of the aperture.

15. An electrical igniter as set forth in claim 13 wherein the ends of said clip and wire are disposed substantially flush with the adjacent end of the insulator.

16. An electrical igniter as set forth in claim 13 wherein the tubular clip has a closed outer end, said covering is foreshortened to provide a projecting end portion of the wire, and said projecting end portion of the wire is wadded beneath said closed outer end of the clip and in electrical contact therewith.

17. A gas range comprising a supporting structure, at least one gas burner mounted on said supporting structure, means for supplying gas to said burner, and electrical ignition means for igniting gas at said burner, said ignition means comprising an igniter support adjacent said burner, a dielectric member mounted on said support and having a bore therethrough, a lead comprising an electrically conductive wire having one end portion positioned within said bore, mechanical gripping means attached to said end portion of the lead for retaining said lead in said bore, a conductive member mounted on said support and having a portion overlying the adjacent end of the insulator in spaced relation to the end of said wire, and means for applying electrical potential to said lead for producing a spark across the gap between the end of the wire and the overlying portion of the conductive member, said gripping means being a threaded metal member disposed at least partially internally of and in threaded engagement with the end of the wire and in electrical contact therewith.

18. A gas range as set forth in claim 17 wherein said metal member extends coaxially of said end of the wire and is embedded therein, with portions of the end of the wire encircling the metal member and wedged between the member and the surrounding wall of said aperture.

19. A gas range as set forth in claim 17 wherein said wire is covered by a flexible covering, said gripping means is a screw member threaded into the end of the wire, and said covering is compressed between the wall of the aperture and the portion of the wire which encircles the screw member.

20. A gas range comprising a supporting structure, at least one gas burner mounted on said supporting structure, means for supplying gas to said burner, and electrical ignition means for igniting gas at said burner, said ignition means comprising an igniter support adjacent said burner, a dielectric member mounted on said support and having a bore therethrough, a lead comprising an electrically conductive wire having one end portion positioned within said bore, mechanical gripping means attached to said end portion of the lead for retaining said lead in said bore, a conductive member mounted on said support and having a portion overlying the adjacent end of the insulator in spaced relation to the end of said wire, and means for applying electrical potential to said lead for producing a spark across the gap between the end of the wire and the overlying portion of the conductive member, said wire being covered by a flexible covering, and said gripping means being a tubular clip interfitted tightly into said aperture between the wall of the aperture and the wire covering.

21. A gas range as set forth in claim 20 wherein the tubular clip has a closed outer end, said covering is foreshortened to provide a projecting end portion of the wire, and said projecting end portion of the wire is wadded beneath said closed outer end of the clip and in electrical contact therewith.

Claims

6. An igniter electrode as set forth in claim 5 wherein said clip has on its outer circumference means interfitting with cooperative areas on the inner wall of the aperture.