US2150728A

US2150728A - Ignition apparatus

Info

Publication number: US2150728A
Authority: US
Publication date: 1939-03-14
Anticipated expiration: 1956-03-14

Description

March 14, 1939. E B, NOWOSIELQK] 2,150,728

IGNITION APPARATUS Filed April 6, 1958 8 INVENTOR.

Edward 5. /V0 wos//sk/ NE Y.

. ig s f- I Patented Mar. 14, 1939 UNITED STATES 2,150,728 v IGNITION APPARATUS Edward B. Nowosielski, Bloomfield, N. 1., assignor to Eclipse Aviation Corporation, a corporation of New Jersey Application April 6, 1938, Serial No. 200,528

19 Claims.

This invention relates to spark plugs, and particularly to those intended for use under severe conditions as to heat development and current intensity, necessitating maximum efliciency in heat dissipation and in electrode construction.

This application is composed of subject matter divided out of my applications Serial No. 16,882,

filed April 17, 1935; Serial No. 29,530, filed July 2, 1935, and Serial No. 62,524, filed February 5,

1936, the two first named applications having resulted in Patents Nos. 2,088,384 and 2,081,500

respectively.

Some of the objects are to provide improved electrodes including novel methods of constructing and assembling the electrodes; to provide improved heat deflecting means; and to provide other improvements and advantageous combinations the nature of which will appear.

These and other objects of the invention will 20 become apparent from inspection of the following specification when read with reference to the accompanying drawing wherein is illustrated the preferred embodiment of the invention. It is to be expressly understood, however, the drawing 25 is for the purpose of illustration only, and is not designed as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

I In the accompanying drawing forming part 30 hereof:

Fig. 1 is a longitudinal sectional view of one embodiment of the invention;

Fig. 2 is a bottom plan view of the plug shown in Fig. 1;

35 Fig. 3 is a longitudinal sectional view of the lower portion of a plug, constituting a second embodiment of the invention;

Figs. 4 to 8 inclusive, indicate the appearance of the element 86 of Fig. 3 as it passes through 40 the successive stages in the process of forming it into its final condition. 7

As shown in Figs. 1 and 2 the plug base ll receives the ground electrode 8, electrically welded or otherwise united thereto along one or more 45 cylindrical surfaces such as those indicated at 5 and 6, between which surfaces there is a peripheral groove providing an annular space adapted to be filled by metallic ring 4 of a softer material such as copper having greater heat conductivity 50 so as to facilitate the dissipation of excess heat. It will also be noted that although the normal path across which the high tension current will jump includes that portion of the electrode which is directly below the base of the central electrode 1, there is an auxiliary potential spark gap across to the inwardly extending circular ledge indicated at 3; but the primary purpose of this ledge 3 is to constitute a baiile to impede entry into the interior of the plug of objectionable products of combustion. c To conform to standard practice, shell H may be made from suitable free-turning steel, while electrode 8 will be made from bendable metal having good spark resistant qualities, as, for example, a nickel-manganese alloy. 10

As shown, the plug is of the completely shield-- ed type including an apertured shielding element II] which is shown as an upward extension of the base ll, there being an intermediate polygonal portion H which receives a wrench or other tool for insertion of the plug in the cylinder wall. The lower portion of the element I0 is also shown as provided with a polygonal section I3 facilitating its attachment to the shell II, but it is to be understood that the two members l0 and II may be integral if preferred.

Also as shown in Fig. 1, the insulator 20 is of ceramic material such as Isolantite or other porcelain, positioned solidly within the shell by the action of threading parts 10 and H together. This action holds the insulator 20 againstthe shouldered portion of the shell, a seal against escape or entry of fluid being effected at this point by the provision of the gasket 3| engaging the shoulder 30. Above and below this shoulder 30 30 the insulator is internally threaded as indicated at 33, to cooperate with corresponding threads on a metallic sleeve of copper or other material having good heat conducting'oualities, whereby a substantial amount of heat may be taken from 35 the electrode I and spindle l4 and transferred through the insulator, to be dissipated from the surfaces thereof, by the cooling air currents entering and leaving the space adjacent radial outlets 3. 40

In the space within the element Ill there is a second cooling and ventilating chamber surrounding a long thin heat radiating metallic jacket l5. This jacket I5 is lined with a tube l6 of rolled mica constituting the wall of a third annular chamber closed at its upper end by a nonconducting spacer tube l1 having a metallic skirt l8 adapted to engage the mica lining l6 of jacket l5 and thus facilitate transfer of heat from the central electrode spindle ll to the outer surface of jacket 15, where it may be conveyed away by the cooling air current circulating around said jacket. I

Above the hollow upper extension I! of the spindle I4 there is provided a connecting pin 12 1 having an enlarged lower part 39 against which the upper end of coil spring 36 engages to urge the chisel edged upper end of the pininto penetrating engagement with the stranded wire cable core ll.

The spindle extension I9, which is riveted to the spindle, serves a double purpose: first, it keeps the spring 36 in place, and secondly, it tends to transfer a large measure of excess heat to the copper ferrule 28, for ultimate radiation by way of jacket l5.

As shown, the insulated cable 46 is adapted to pass through a metal thimble or elbow 31, the latter having a flanged ring 38 soldered to its lower end and pivotable within the detachable coupling member 52 threaded on the end of the shielding element I 8. Before attaching the thimble 31 the spacer tube ll of Bakelite, or other rigid insulating construction, is inserted to fit about electrode connection 34, with its skirt l8 telescoping with washer 28. The upper end of the tube I1 is flanged, as at M, to rest upon asbestos disc 45 and overlie the upper edges of mica lining 16, and thus protect the mica lining against fraying or bending out of position.

After passing the cable through the elbow thimble 31, a metal bracelet or collar 43 is pressed tightly about the rubber coating of the cable, at a point which is a pre-measured distance from the end of the cable. Coupling nut 52 and thimble 38, the latter being recessed to form an annular ledge are then moved forward into the assembled relationship shown, wherein thimble 38 serves as a thrust bearing to prevent withdrawal of the cable so long as coupling member 52 remains in place as shown. When the member 52 is unscrewed from the shielding element In and drawn back (together with thimble 31, 38) along the cable, the latter may then be withdrawn and inspected, but spacer tube l1 will remain in place due to the fact that the spun-over end 6| of element l0 holds upper metallic washer 41 and flange 44 against displacement.

Preferably spacer tube I1 is grooved circumferentially, as indicated at 62, to facilitate heat dissipation and also to provide space for retention of a binding cement, if it is desired to apply such an auxiliary holding substance.

In assembling the plug elements the first step is to braze or otherwise permanently weld the electrode spindle l4 within the metallic sleeve 35, and the second step is to apply a suitable cement to the threaded surfaces 33, so that upon threading the spindle carrying sleeve into the porcelain core 20 to the desired distance, the spindle will become securely bonded to the core 20 by virtue of the cement confined between the registering surfaces of the sleeve 35 and the bore of the core 20. This cementing step, in conjunction with the gasket 31, renders the plug air and gas tight.

In forming and installing the type of electrode shown in Figs. 3 to 8, the first step is to secure an H-shaped metallic piece 86 of suitable heat and spark resisting qualities while at the same time a sufficiently good conductor. Such a piece is indicated in Fig. 4. This piece is then subjected to a bending operation to bring it into substantially the form indicated in Fig. 5. Next the parallel sides 81 and B8 are turned into semicircular arcs which preferably do not quite join (as indicated in Figs. 6 and 7) the cross-connecting portion remaining in the form to which it is initially bent, as shown in Fig. 5. The final step in formation of the electrode is to shape the upper annular surface formed by the semi-circular parts 81 and 88 so that in transverse section it will have the final appearance indicated "in Fig. 8. When thus completed the electrode receives a thin dished washer 9| of soft metal such as copper and then a second dished washer 92 of harder material and preferably the same material as the electrode 86 itself. The installation and completion of the electrode assembly is then obtained in the following manner: The shell 36 is placed on a table or work-bench with its lower counter-bore 96 upper-most, a thin cupshaped liner 91 of soft metal, preferably the same material as that of the piece 9|, and centrally apertured to a diameter corresponding to the diameter of the chamber 34, is then inserted in the recessed end 96. The electrode assembly consisting of the parts 86, 9| and 92 is then placed in position within the inverted cup member 91 and the assembly consisting of the

parts

36, 91, 92, 9| and 86, is then placed in a hydrogen gas furnace or other suitable heat chamber and subjected to a temperature sufficient to cause a fusion or welding along the surfaces of the elements 91 and 9|, with the result that the five elements above enumerated become fused into a permanently welded single unit. This unit is then removed from the furnace, the core assembly, the shield extension assembly, and upper cable assemblies successively attached thereto in the respective manners above indicated. When this complete assembly has been accomplished it will be found that the inner electrode 25 occupies a position approaching that of the transverse portion 86 of the outer electrode and also approaching that of the inner cylindrical edge 99 of the thimble 92, forming an auxiliary spark gap, the clearances therebetween being such that the spark will normally jump from the relatively broad surface of the electrode 25 to the correspondingly broad plane surface of the cross-piece 86 of the ground electrode; but if for any reason this normal path of the spark is obstructedas for example by the formation of ice particles-the spark can then jump from the cylindrical surface of the electrode 25 to the above described cy1indrical surface 99 of the thimble 92 which may therefore be considered as a part of the completed electrode. In fact it is, of course, possible to have the elements 92, 9| and 86 originally formed as an integral whole rather than being composed of three subsequently united pieces as shown.

The electrode cup 25 is initially of uniform bore, so that it may be slipped over the enlarged base of spindle l2 and its covering sleeve 95 (as indicated in Fig. 3) and then secured in position thereon by a pressure sufficient to change the cross-section of the upper end of said cup 25 to cause its contour to conform to that of the spin dle base and sleeve 95 (all said parts being fused into a unitary assembly during the process)- the final shape of the cup 25 being as indicated in Fig. 3. If the pressure applying step does not in and of itself generate sufficient heat for the fusion of all parts in the manner above indicated, there may be a separate application of heat for such fusing purpose.

What is claimed is:

1. In a spark plug, the combination of a shell or base of one metal, a perforated electrode of a second metal which is resistant to the spark, said electrode having two separate circumferential surfaces adapted to be welded to said shell, and a third metal of good heat conductivity interposed between said two circumferential surfaces to facilitate transfer of heat from said electrode to said shell, said third metal being within the confines of said perforated electrode, and therefore protected from exposure to burning gases.

2. In a spark plug, the combination of a shell or base of one metal, a perforated electrode of a second metal which is resistant to the spark, said electrode having two separate circumferential surfaces adapted to be welded to said shell, and a third metal of good heat conductivity interposed between said two circumferential surfaces to facilitate transfer of heat from said electrode to said shell, said third metal being in the form of a ring having an outer diameter corresponding to that of said electrode, and said electrode also having an inwardly extending circular ledge constituting a baffle above the sparking region of the plug.

3. In a spark plug, the combination with a central electrode of a shell of one metal, an outer electrode of a second metal which is resistant to the corrosive action of the spark, said outer electrode having a portion extending across the shell opening-below the base of the central electrode, and a third metal of good heat conductivity integrated with said electrode, said outer electrode being in the form of a ring having a ledge portion constituting a baflie disposed above the sparking region of the plug.

4. In a spark plug, the combination with a central electrode of a shell of one metal, an outer electrode of a second metal which is resistant to the corrosive action of the spark, said outer electrode having a portion extending across the shell opening below the base of the central electrode, and means integrated with said electrode to form a ledge portion constituting a baffle disposed above the sparking region of the plug.

5. In a spark plug, the combination with a central electrode of a shell of one metal, an outer electrode of a second metal which is resistant to the corrosive action of the spark, said outer electrode having a portion extending across the shell opening below the base of the central electrode, and a third metal of good heat conductivity adjacent said electrode, said outer electrode being in the form of a ring having a ledge portion constituting a baflie disposed above the sparking region of the plug.

6. In a spark plug, the combination with a central electrode of a shell of one metal, an outer electrode of a second metal which is resistant to the corrosive action of the spark, and a third metal of good heat conductivity integrated with said electrode, said outer electrode being in the form of a ring having a ledge portion constituting a bafile disposed above the sparking regio of the plug.

'7. In a spark plug, the combination with a central electrode of a shell of one metal, an outer electrode of a second metal which is resistant to the corrosive action of the spark, and a third metal of good heat conductivity adjacent said electrode, said outer electrode being in the form of a ring having a ledge portion constituting a baffle disposed above the sparking region of the plug.

8. In a spark plug, the combination with a central electrode of a shell of one metal, an outer electrode of a second metal which is resistant to the corrosive action of the spark, said outer electrode having a portion extending across the shell opening below the base of the central electrode, and a' third metal of good heat conductivity integrated with said electrode, said third metal being within the confines of said outer electrode,

and therefore protected from exposure to burning gases.

9. In a spark plug, the combination with a central electrode of a shell of one metal, an outer electrode of a second metal which is resistant to the corrosive action of the spark, said outer electrode having a portion extending across the shell. opening below the base of the central electrode, and a third metal of good heat conductivity adjacent said electrode, said third metal being w thin the confines of said outer electrode, and therefore protected from exposure to burning gases.

10. In a spark plug, the combination of a shell or base of one metal, a perforated electrode of a second metal which is resistant to the spark, said electrode having two separate circumferent al surfaces in contact with said shell, and a third metal of good heat conductivity interposed between said two circumferential surfaces to facilitate transfer of heat from said electrode to said shell, said third metal being within the confines of said perforated electrode, and therefore protected from exposure to burning gases.

11. In a spark plug, the combination of a shell or base of one metal, an electrode of a second metal which is resistant to the spark, said electrode having two separate circumferential surfaces adapted to be welded to said shell, and a third metal of good heat conductivity interposed between said two circumferential surfaces to facilitate transfer of heat from said electrode to said shell, said third metal being within the confines of said electrode and therefore protected from exposure to burning gases.

12. In a spark plug, the combination of a shell or base of one metal, an electrode of a second metal which is resistant to the spark, said electrode having two separate circumferential surfaces in contact with said shell, and a third metal of good heat conductivity interposed between said two circumferential surfaces to facilitate transfer of heat from said eelctrode to said shell, said third metal being within the confines of said electrode and therefore protected from exposure to burning gases.

13. A spark plug comprising a shell, a ground electrode carried by the shell, a metallic heat conductive sleeve, of higher conductivity than the shell and electrode, positioned within the shell and in good conductive relation to the latter and also in good conductive relation to the electrode, all parts of the sleeve being shielded from direct contact with the burning operating charge.

14. A spark plug comprising a shell, a ground electrode carried by the shell, and a heat bridge, of higher conductivity than the shell or the ground electrode, in good heat conductive relation with both the shell and grounded electrode and shielded from direct contact with the burning operating charge, said heat bridge extending into the interior of the ground'electrode.

15. A spark plug comprising a shell, a ground electrode carried by the shell, and a heat bridge within the confines of the ground electrode and extending into good heat conductive relation to the shell, and shielded from direct contact with the burning operating charge.

16. In a spark plug, the combination of a shell or base of one metal, a perforated electrode of a second metal which is resistant to the spark, said electrode having two separate circumferential surfaces adapted to be welded to said shell, and a third metal of good heat conductivity interposed between said two circumferential surfaces to facilitate transfer of heat from said electrode to said shell, said third metal being in the form of a ring having a same outer diameter as said electrode.

17. In a spark plug, the combination of a shell or base of one metal, a perforated electrode of a second metal which is resistant to the spark, said electrode having two separate circumferential surfaces adapted to be welded to said shell, and a third metal of good heat conductivity interposed between said two circumferential surfaces to facilitate transfer of heat from said electrode to said shell, said third metal being in the form of a ring having a same outer diameter as said electrode, said electrode also having an inwardly extending circular ledge constituting a baffle above the sparking region of the plug.

18. In a spark plug, the combination with a central electrode of a shell of one metal, an

outer electrode of a second metal which is resistant to the corrosive action of the spark, said outer electrode having a fiat portion extending below the base of the central electrode, and a third metal of good heat conductivity integrated with said electrode, said third metal being in the form of a ring having a ledge portion constituting a baffle disposed above the sparking region of the plug.

19. In a spark plug, the combination with a central electrode of a shell of one metal, an outer electrode of a second metal which is resistant to the corrosive action of the spark, said outer electrode having a flat portion extending below the base of the central electrode, and means integrated with said electrode to form a ledge portion constituting a bafile disposed above the sparking region of the plug.

EDWARD B. NOWOSIELSKI.