US1266561A - Spark-plug. - Google Patents

Description

Patented May 21, 1918 compact and vdependable, and arran may be UNITED STATES PATENT OFFICF PAUL O. DEPEW, 0]! CHICAGO, ILLINOIS SPARK-FLUO- Specification of Letters Patent.

Patented May 21, 1918.

Application filed Inn: 9, 1815. Serial No. 33,008.

One of the ob ects of my invention is to provide a spark plug constructed and operated so that the spark at the terminals will at all times be maintained clean, means being provided for preventing the accumulation thereon of carbon deposit.

A further object of my invention is to provide a s ark plug comprisin means for automatica y passing air into e cylinder 'duiingzthe suction stroke of the piston.

rther object of my invention is to provide a simple ark Ehhg comprising mwdeans forprimingt e cy 'n er in case of n V Ingeneral the object pf my invention is to provide a spark plug which is aim is, so terminals will be main-.

that the rk spa ga at the air will be autotained clean, so

.matically admitted during the suction stroke of the cylinder, and so that the cylinder companymg drawings Fi re 1 is an elevation of a spark plug which embodies features of my mvention; Fi 2 is a central longitudinal section of t 0. p rk plug; Fig. 3 is an end view thereof; Fig. 4 1s a central transverse section thereof; Fig. 5 is a central longitudinal section of a modified form of sparkplu-gi The spark plug which I i ustrate in this instance as my preferred form comprises a casing 5, the casing having external threads 6 at one end, for the purposeof screwi' into the casingof the c linderin the ordinary manner, internal reads 7, and-a central longitudinal passageway 8' extending the entire length of the casing. The pas-- sageway 8 is materially restricted at the lower end of the casing so as to form an aperture 9 the walls of which form the grounded terminal of the spark gap.

Threaded into the threads 7 of the upper end ofthecasingistheprotectingcasmg primed when desired. In the ac-' ivardly through cylinder 10. An annular insulating member 11 is fitted into the central portionvof the casing and is held in place by means of the proltecting casing 10, gaskets 28 preventing leakage, in an ordinary manner. The insulating member may be made of an suit able material; I prefer porcelain or the pug pose.

wed in the member 11 is an annular member 12 having a valve seat 13 ground on the lower end thereof. This member 12 may be cast in the porcelain 11 or fixed therein in any suitable manner. A valve 14 is adapted to coaot with the valve seat 13, and has a valve stem 15 projecting upwardly through member 11 and through a guide piece 16 which is fixed in the porcelain. The stem 15 is free to move longitudinall and a compression spring 172encircles t e stem, between the grade 16 and the nut 18 threaded onto the valve stem,- and thus tends at all times to hold the valve '14 in contact with the seat 13. Extcndin downwardly from the valve 14 is a rod 1 the lower end, of which forms the inner terminal 31 of the spark gap.

In operation, at the time of the suction j stroke of the piston the reduced ressure m the cylinder, and hence in the c amber 29 of the passageway 8, allows the ressure of the external air to overcome t o upward tendency of the spring 17 and to force the valve 14 downwardly, and thus more or less air is'allowed to enter the cylinder through the passageway 30, the amount depending upon the tension of the spring 17, as controlled by the nut 18. The air passes down- 'the chamber 29 and the 9, and is thus forced at n-high speed a inst the spark gap terminals 31 and 32, lowing therefrom any particles of carbon that may have adhered thereto at the time of the last explosion. \Vhen the comression stroke occurs the gas in the cylinder is forced upwardly through the aperture 9, forcing the valve 14 cl&ed, and a the same time forcing the gas against the spark gap terminals and tending to further clean the surfaces thereof. Finally when the explosion occurs gas is forced upwardly through the aperture 9 and then downwardly again, as the pressure in the becomes less than the pressure in So that there is a conback opening the passageway 29. tinual vibration of air at high speed and forth throu h the a erture 9 tending to clean the sur aces of t e spark gap terminals.

Although the particular arrangement shown is not material to my inventlon, yet in this instance I have connected, the wire 20 which leads from \the magneto to the rk plug, to the upper end of the valve 5 In 15, immediately above the nut 18, by means.of a washer 22 held firmly against the terminal 21 of the wire by a spring 23 held compressed by means of the clip 24 and nut 25. This pressure of the spring is Buflicient to hold the terminal 21 in place; but it m'ay be removed or replaced by forcing the terminal from, or in, between the nut and washer.

If it is desired to prime thc cylinder, it is necessary only to pour the gasolene through the aperture 26 of the protecting casing. If desired the valve stem may then he forced dmvnwardly, so as to allow the gasolenc lo pass inwardly; or the suction stroke of the piston ma be depended upon to open the valve and a low the gasolene L0 ass inwardly. In either case the gasoene will ass downwardly and will come in contact with the surfaces of the spark gap terminals, and will assist in keeping the surfaces clean.

By the arrangement of parts shown and described it is evident that the protecting casing 10, the porcelain 11, andthe inner spark gap terminals 31 may all be removed without removing the casin 5 from the cy'linder; and thus all parts 0 the spark plug maybe examined or replaced conveniently;

and the external terminal 32 of the s ark gap may also be cleaned as desired wit rout removing the casing 5.

Fig. 5 illustrates a modified form of spark lug. which nlso'embodics features of'my invention. The air and gasolcne'inlet casing 35 is attached to the side of the casin 36 of the plug; and the valve 37 is mounts as indicated in the casin 35, V Although I have descri d with somc-particularity devices whichembody the features of my invention, yet it is to be ur'idorstood that various modifications may be made therein by those skilled in the art without departing from the svirit of my invention as indicated by the fo lowing claims.

I claim as my invention- 1. A spark p ng, eomprisim a lube a. conductor slidably mounted in the bore of said tube; a valve fixed to'sn-id conductor; a member fixed in said tube and encircling said conductor adjacent said valve, said member having a valve seat, the walls of said seat diverging downwardly; and yielding means tending to-hold said valve against conductor upwardly and to old the valve against. the seat; and means for connecting an electric conductor to the upper end of said conductor.

3. A spark plug comprising a casing, said casing having a passageway therethrough, an insulation bushing in sai passageway, a member mounted in said bushing and ving a valve seat on its lower end, said bushing extending a material distance above said member, a conductor slidnbly mounted in said bushing, a valve fixed to said conductor below said valve'seat, an electric conductor detachably connected to the upper end of said former conductor, and means tendin to force the said former conductor upwar ly and to hold the valve against said seat.

4. A spark plug comprisingla casing, said casing having a passageway erethrough, a member mounted in said passageway, said to force the member having a downwardly diverging valve seat on its lower end, a conductor pass--= iug through said member and said passageway, the lower end of said conductor being adjacent the 'walls of said casing, a valve fixed tothe said conductor below said valve seat, and yielding means tending to force and to hold the the conductor upwardly valve agaiust the seat.

e 5. A spark plug comprising ductor slidably mounted in ti a'tube, a cone bore of sa d tube, a yalve fix'ed to saidcondiictor, ameniber fixed in said tube and encircl ng said conductor adjacent'said valve, said member having a valve seat,-the walls of said valve seat diverging downwardly, and yielding means tending to hold said valve against said seat, lhe lower end of the bore of said lube being materially restricted, the inner surface of the said restricted lower end beiug formed to converge downwardly to the end opening, said valve arranged to open by an cxress external pressure.

In testimony whereof, I hereunto set my hand.

PAUL C. DEPEW.

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