US2109029A - Ignition apparatus - Google Patents

Description

E. B. NOWOSIELSKI IGNITION APPARATUS F eb. 22, 1938.

Filed Jan. 18, 1957 INVENTOR. -dward B. /Vowos/'e/S/ ORNE Patented Feb. 22, 1935 UNITED STATES PATENT to Eclipse Aviation Corporation, East @rang-:es N. J., a corporation of New Jersey Application January it, i937, Serial No. lglcili 5 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 efficiency in heat dissipation and in electrode construction. The application is a continuation, in part, of my application Serial No. 16,882, led April i7, 1935, and in part, of my application Serial No. 29,530, iiled July 2, 1935.

Some of the objects are to provide improved electrodes including novel methods of constructing and assembling the electrodes, and of adjusting the spark gap; to provide improved heat deflecting and cooling means; and to provide improvements in the manner of insulating the current; including a novel method of insuring against development of pipes along the edges of the rolled mica sheets employed as part of the insulating means; and to provide other improvements and advantageous combinations the nature of which will appear.

In the accompanying drawing forming part hereof:

Fig. 1 is a view in elevation ci one embodiment of the invention;

Fig. 2 is a longitudinal sectional view of the plug shown in Fig. l but on an enlarged scale;

Fig. 3 is a bottom plan view o1 the plug g Fig. 4 is a sectional View of the central electrode in course of formation; and

Fig. 5 is a diagrammatic view showing an alternative shape for the electrodes ill/6 and IUS of Fig. 3.

For the purpose of a shielded aviation sparirplug the metal body i0 of the plug is provided with a shield extension Il which extends upward considerably above the upper end of the spindle i2 to enclose the spindle and the electrical connection between the same and the conductor which leads the high-tension current to the spindle. This extension is preferably'in one piece with the attaching nut 5, though such unity is not necessary.

Instead of completely closing the space between the shield extension Il and spindle I2, 'i provide a cooling and Ventilating chamber I3 in the form of an annular space betweenfthe shield extension Il and a long thin cylindrical metallic sleeve I4 having low thermal conductivity, and lined with a tube I5 formed of rolled mica constituting the wall of a second chamber IB bounded at its lower end by the upper surface of the compressible metal gland i1, and at its upper end by a, novel heat deflecting and sealing assembly more fully described, as well as claimed, in my (Ul. 12E-mit) parent application No. 16,882, above referred tc. The same is true as to those other elements not discussed in detail herein; the detailed description herein being conned to those features which are more particularly the subject oi this continuation application. Aincng these is the central electrode lill? Whose outer surface has an elliptical contour, as indicated best in Fig. 3, While the cooperating parallel walls lill and Hill oi the outer electrode ill@ a parallelogram in transverse section as vie true elliptical contol i" arcs and parallel Either arrangement permits ready adjustment of the spark gap by producing relative angular motion between the parts it@ and ltd about the common axis oi said parts. This adjustment can be eiected by inserting in the space between the two elements a gage of proper thickness to give the desired spark clearance and then applying said gage to the elements as a lever to cause one oi said elements to turn sufficiently to produce the desired clearance therebetween. desired the electrode ill@ may be integral with the recessed end @d of the shell fili but l prefer to have it as a separate piece fused or welded thereto through the instrumentality of a joining piece il l oi a soft metal similar to that of the sleeve of Fig. 2 and fused thereto, preferably the same manner as hereinaiter outlined in connection with the description of the parts constituting the central electrede assembly as shown in Figs. 2 and fl.

in the construction shown in Fig.- 2 l have in terposed an annular member lid of low heat conductivity such as asbestos, to provide a further means of deiiecting the heat of the spindle in a radial direction at this point in the plug thereby adding to the heat delecting capacity oi the copper gland il'. The latter is also shown as having a series of heat conducting Wires or rods l@ embedded therein and extending down into openings in the mica Washer it to absorb heat therefrom and conduct such heat 'toward the outer Wall of the plug. pered surface for registering with a correspondingly tapered seat iid in the shell 3E, to supplement the heat dissipating action of the soft metal rods I9, and the annular soft metal seat in Fig. 2 also aids in such heat dissipation. Also in this secondembodirnent I provide a pedestal H'l made of carborundum or stainless steel having low heat conductivity to reduce the amount of heat entering contact spring 6l which main- Gland il also has a ta- A tains the electrode pin 62 in contact with the conductor 66.

In View of the wider clearance shown in Fig. 2 as between the inner wall i4 and the outer shield extension il there is a correspondingly greater distance between the upper vsurface of the mica lining iii and the inner wall M, which greater distance maires it advisable to employ in place of the ferrule shown at 'i9 in my application No. 16,882, a non-metallic spacer di of sturdier dimensions, and low thermal conductivity, the lower end of said spacer resting upon the shoulder 3i of the wall it while the upper end extends across the upper edges of the layers of the micalining band rests 'lightly thereon, the inner diameter of this upper rim lid being slightly larger than the outer diameter of the spacer 'il so as to provide a clearance therebetween. Spacer lll! is therefore free to move upwardly beyond this rim il@ but only to the point of contact with the annular rim il@ on the swivel member idd. 'I-he said memberv it@ is internally threaded to receive a correspondingly threaded gland iti of steel or similar material to rmly grip the inwardly turned end H22 of a metallic corrugated tube M3 which by reason of the pressure exerted thereupon by the application or' the nut i211 is pressed firmly upon the beveled annular seat i243 to a bonding member i225, constituting the means for providing a firm electrical bond between the shielding elements E23 and i169, the latter being in firm contact with the complementary shielding element i Il by reason of the pressure exerted thereupon by the act or tightening the coupling nut 'H threaded to the upper end of the shield extension i l. This nut 'li is shown at Hl (Figs. l and 2) as milled out horizontally and also vertically to increase the effectiveness of the hold. This milling provides flexibility which facilitates establishment of a locked connection by the exertion of inward pressure upon the open ends.

In both embodiments there is provided acompletely shielded plug including a detachable conductor having aconnection with the plug facilitating connection of the cable regardless of the angle required and providing in each case improved insulating and heat dissipating means as Vwell as improved methods of spark production and adjustment. While both of the embodiments illustrated possess obvious practical merit in each v of the respects above described, it is to be understood that latitude is to be allowed Within the scope of the respective claims appended hereto.

The electrode cup |06 is initially of uniform bore, so that it may be slipped over tlfe enlarged base of spindle l2 and its covering sleeve 95 (as indicated in Fig. 4) and then secured in position thereon by a pressure sufficient to change the cross-section of the upper end of said cup |06 and cause its contour to conform to that of the spindle base M06 and sleeve 95 (as shown in Fig. 2) all said parts being fused into a unitary assembly by the process.

What is claimed is:- i. In a spark plug having a central spindle surrounded by a stack of insulating discs, and an enclosing shell, the combination with said discs, spindle and shell of metallic rneans extending through apertures in said discs for facilitating rapid transfer of heat from. said discs to said shell.

2. In a spark plug having a central spindle surrounded by a stack of insulating discs, and an enclosing shell, the combination with said discs, spindle and shell of ymetallic means including rods extending through apertures in said discs forfacilitating rapid transfer of heat from said discs to said shell.

3. In a spark plug having a central spindle surrounded by a stack of insulating discs, and an enclosing shell, the combination with said discs, spindle and shell of metallic -means including a pressure gland and a series of rods extending through apertures in said discs for facilitating rapid transfer of heatrfrom said discs to said shell. Y

e. in a spark plug having a central spindle surrounded by a stack of insulating discs, and an enclosing shell, the combination with said discs, spindle and shell'of metallic means including a pressure gland and a series of rods extending through apertures in said discs for facilitating rapid transfer of heat from said discs to said shell, and means for causing air to circulate EDWARD B. NoWosrELsKr.

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