US1247049A - Spark-plug. - Google Patents

Description

' w. WILLEN.

` SPARK-PLUG. APPLICATION FILED JUNEZ, |915.

Patented Nov. 20, 1917'A inve-nto@ l. William magg @Umweg f WALL'ACE WILLETT, 0F EAST ORANGE, NEW JEBIISEY.

SPARK-PLUG'.

' Specication of Letters Patent. i Patentd NOV, 20, 1917,

Application led .T une 2, 1915. Serial No. 31,548.

To allwhomvz't may concern.'

Be it -known that I,' WALLACE WILLE'rr, a

citizen'y of the United States; and resident of East Orange, inthe county of Essex and State of New Jersey, have invented certain new and useful Improvements in Spark- Plugs, of which thel following is a specificatlon. My invention relates to improvements in s park plugs ofthe type particularly desi'gned to be mounted on internal combustion engines to produce the iiring spark in the combustion Vvchamber. v

The sparking points or electrodes of spark plugs now in general use frequently become fouled and sometimes short circuit'ed by the deposit of carbon on the sparking surfaces.

It is the present practice when a. spark plug becomes fouled either to remove one of the electrodes from the plug without unscrewing the plug from the engine, or to unscrew the entire plug from the englne casing. By the former plan the sparking surface or sur-Y faces .on only one side of the circuitare -thread to wear the threads in the engine cleaned. By the latter plan the threads in the engine casing are subjected vto considerableA wear. This wear is cumulative in the engine casing, vbecausev the plugs are replaced from time to time as they wear out, and therefore each fresh plug presents a new casing.' VBy either plan it is necessary to replace -the entire plug whenever a plug is worn out. y

The object of my invention is to provide a simple form of spark plug of readily demountable parts, the `outer containin shell or casing of which may be detachalSi/l cured in the wall of the combustion chamber with the velectrodes and insulating member thereof constituting a removable unit, for insert in andfrcnioval from the shell. By this construction'all of the sparking surfaces `may be removed vfor cleaning without disturbing the shell Ascrewed into the engine "casing, and in order to replace a defective plug it isonlyl necessary to substitute one or more of the parts ofthe demountable unit without dlsturbing the shell which is screwed into the engine casing. i

Various other objects and advantagesy of the invention will beinpart obvious from an inspection of the accompanying` drawing and in partfwillhe more *fully set forth in ,forth and claimed. f

vention shown mounted in position in'th i 'length to form a c vlilidrical flange 20 de-,

`the following particular." description of one f orm of mechanism embodying my vinvention, and the invention 'also consists in certain new and novel features of construction and 'combination of parts hereinafter set In the drawings: I v l 'Figure l is a sectional View taken axially througha preferred embodiment of my inwall of a combustion chamber;

F1g.`2 is an enlarged end view of the sparking end of thespark plug; and

Figs. 3 and l are each compound views Y showing a side elevation and an end view respectively of the twofspark gap forming members.

In the following description and-inthel claims, arts will ,V be identiedby specific namesV or convenience` of expression ibut theyare intended to bey as generic in their i application to similarl parts as the art will permit.

In the drawings there is shown a ortion 5 of the wall outlining the com nstion chamber of an engine. j The wall is provided. with a. screw threaded' opening 6 for the in'- sertion of a spark plug"as is usual with de-fie vices of this character. A spark plug 7. isffyl inserted-in this opening and comprises arab shell container 8 having a reduced end-M1;

screw-threaded into engagement with the. 1" opening 6. This shell `is provided with a bore v10, the upper end of which is screw threaded as shown atll, the lower end of which' is frusto-conical as shown' at 12 with the smaller end adjacent the inner end\"'of the shll, and the intermediate portion of the bore cylindrical as shown at 13.A The frustoconical portion 1'2 isreduced from the cylindrical portion to `form a shoulder 14 providing a seat for a packing ring l5. The lower end of the shelhis concaved to form an electrode containing-,recess 16. y The bore is adaptedto contain a remov' able'unit comprising thi-ee elements. an insulatingcore 17 and 'tworco-aeting spark gap forming members 1S and 19 carried thereby. The insulating core 17 is preferably formedV of porcelain and enlarged" intcrmediateitsl signed to fit within the cylindrical portion' 13 of the boreand tooverlap the shoulder 14;; Opposite sldes of the flange are rounded lower end with substantially the saine anglev into the end portions of the core. The lower portion of the core is tapered towardl its of taper 'as the frusto-conieal portion 12 of the bore. y

The member 18 is in the form of a con- Y ducting rod which extends longitudinally through the core 17, projects beyond oppo- .site ends of the same and has its lower end provided with a plurality of electrodes'21, which, in this embodiment of the inventlon, are show-n to be three spheres projecting laterally from the rod and arranged 120 apart in t'he'form of a circle. The upper end of the conducting rod is screw-threadedY as -shown at 22 and co-acts with the cap 23 fittingthe upper end of the core and with the nut 26 to form the usual binding post.

The member 19 is formed of a frustoconical sleeve 27 ydesigned to be fitted to the i tapered portion of the core with a frictionally tight lit. i The upper end of the sleeve is formed into an outturned flange 2S designed to fit between the curved face of the iange 2O and the ring 15. The small lower end of the sleeveV 27 is provided with a plurality of electrodes 2f), in this embodiment of the invention shown to be three in number, projecting downwardly N and slightly.

inwardly from the end of the sleeve'and adapted to be disposed between the electrodes 21 to form six spark gaps as shown lin Fig. 2, with each electrode disposed between two electrodes of opposite polarity.

The removable unit is positioned in the shell with the electrodes in the recess 16 and is removably held in place by a bushing 30 engaging the outer threaded end 11 oi the bore. This bushing has a rounded end '31 ,designed to engage the rounded top vof the flange 2O to force the unit into engagement vwith the packing ring 15.

Should .it be desn'ed'to clean the el eclrodes the bushing is unscrewcd and the unit including the electrodes and insulating cere is simply lifted out of the shell container 8 leaving the shell container inA its screwthreaded engagement with the engine casing. This provides a ready access to both sets of electrodes while mounted in.' their.

, spark gap'forming position, but should 4it be desired to separate the elements. forming the removable unit itis merely necessary to loosen the nut and. washer forming the binding post and the conducting rod may be withdrawn from the core.- The sleeve may then be pulled off thecore vand the parts separately cleaned.

-When assembled the position of the electrodes relative to each other may be varied` from a pos1tion exteriorly of the engine casing by rotating the cap 23 which will raise or lower the electrodes 21- relative to the electrodes 29 and there is thus provided a .self-,cleaningconstruetion.

ing and'in this way the threads are not worn A and the spark plug is always securely mounted in place. Either of the electrodes may be removed for cleaning or renewal without disturbing the portion of the plug which is screwed into theengine casing. But even if the entire plug is removed and replaced when it is worn out, the threads in the engine casing will not be materially worn, because this replacement does not takeplace very frequently.

While I have shown and described, and have pointed out in the annexed claims, certain vnovel features of my invention, it will be understood that various omissions, substitutions and changes inthe form and details of the device illustrated and in its opsoY eration may be made by those skilled in the art withoutl departing from the spirit of the invention.

Having thus described my invention, I A

claim:

1. In a spark cluding a sleeve provided with three ball electrodes extending from one end -thereof andspaced approximately 120 apart and a member positionedl within said sleeve and provided with three ball electrodes positioned approximately 120 apart and each designed to be positioned between adjacentv electrodes from the sleeve thereby to form a plug, a removable unit indemountable ringfof six spark gaps and stems connecting each ball electrode with itscorrelated sleeve or member thereby to project the electrodes from their supports and with the centers of the balls disposed in a. circle and equally spaced.

v2. A spark plug having a slightly concaved recess at one end, and a ring of spaced apart electrodes protected within said recess,

said plug comprising a-containing shell, a sleeve itted in said shell and an insulating core fitted within said sleeve, said shell, sleeve and core having recessed ends coactively designed to form the said electrode -containing recess, said sleeve provided with one of the electrodes forming said ring and a conductor lpassing through said core ,and provided with another of the electrodes lforming said ring.

3, A demountable unit constituting part of a spark plug and designed to ftin a. containing shell, said unit eomprisin 'a :member provided with a` pluralityof si ned to be arranged in a circle with eacho the ball points of one member disposed between a pair of ball points of the other member.

' 4. A spark plug comprising a containing shell provided with means for mounting the same in position, a unit frictionally connected to said shell and comprising three ele- '.ments, two of said elements constituting conducting members and each of said two elements provided with a ball point projection constitutingl a teminalpoint designed coactively to form a plurality of spark gaps, and the third element constituting an insulation designed, when assembled with the conducting members to extend substantially the entire length of one of the conducting members,'except its terminal point, thereby to insure the insulation of the members from each other, the upper end ofl said third element extending above the other conducting Copies of this patent may be obtained tor member thereby to provide anu-insulated haii' dle for removing said third element.

5. A spark plug comprising a containing shell provided with a frusto-conical bore constituting a seat, a frusto-conical sleeve shaped to have its entire length lit in said seat with its upper'end spaced below the top of the shell and provided with an electrode extending from the reduced end thereof, lan insulating core having a portion designed to fit in said frusto-conical sleeve and to cover the wall forming the bore of the Sleeve and a rod passedthrough said core substann tially contained therein and provided vwith an electrode designed to coact with the first named electrode to form a spark gap.

Signed at East Orange in the county of Essex and State of New Jersey this twentyifthday of May, A. D., 1915.

. WALLACE WILLETT. Witnesses:

LYDIA H. THOMPSON, J. BooTE.

ve cents each, by addressing the fcomxnissionexI 9! Patenti. Washington, D. C.

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