US1662878A

US1662878A - Spark plug

Info

Publication number: US1662878A
Application number: US200150A
Authority: US
Inventors: George N Barcus
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-06-20
Filing date: 1927-06-20
Publication date: 1928-03-20
Anticipated expiration: 1945-03-20

Description

March 20, 1928.

G. N. BARCUS SPARK PLUG Filed June 20, 1927 nnnmm lllllii:

gwvenkoz Patented Mar. 20, 1928.

UNITED STATES GEORGE N. BARCUS, 0F ANDREWS, INDIANA.

SPARK PLUG.

Application filed June 20, 1927. Serial No. 200,150.

My invention relates to a spark plug and process of manufacturing the same and it 1s an object of the invention to provide a plug in which pressure difl'erences on the gaskets are greatly reduced thus pr0p0rtionately reducing the cause of leakage, and a further object of the invention is in manufacturing to reduce the breakage of insulators and to prevent localized stresses on said insulators, all as will be hereinafter more fully described and claimed.

Referring to the accompanying drawings which are made a art hereof and on which similar reference c aracters indicate similar parts,

Figure 1 is a side elevation of the spark plug constructed in accordance with my invention,

Figure 2, a part side elevational, part sectional view showing in outline the rotating spindles for compressing parts of the plug in assembling, and

Figure 3, a fragmentary detail section of the sleeve shown in Fig. 2 illustrating the method in which the same is rolled or shrunk onto the body member.

In the drawings reference character 10 indicates the body member or shell of a spark plug having its lower end threaded for engagement with the cylinder wall of an internal combustion engine and having an annular flange 11 adapted'to seat on such cylinder wall for limitlng the movement of the body into the cylinder wall. The upper end of the body 10 is provided with an inclined or flared end portion 12 which forms a seat for an insulator 13 of conventional construction. The insulator 13 is provided with a relatively short tapered upper end portion and a slightly longer tapered lower end portion between which is disposed a substantially cylindrical intermediate portion having upper and lower inclined shoul' ders 14 and 15. The insulator 13 is also provided with a central electrode of conventional construction which may be held in place in the insulator by lock-nuts 16 or in any other well known manner.

Means is provided for binding the insulator tightly against the end of the body member or shell 10 and such means comprises a shell or sleeve 17 having a shoulder 18 formed complementary to the shoulder 14 of the insulator and provided with a lower end 19 ofa reduced thickness so that it may be easily rolled or spun into an annular channel or slot 20 on the body member or shell 10.

A gasket 21 is disposed between the shoulders 14 and 15 and the cooperatingabutting surfaces in order to form a gas tight joint when the parts are in assembled relation. The bottom of the annular channel or slot 20 of the body 10 is preferably'knurled at 22 so that when the sleeve and body are pressed together they will be secured in fixed relation to each other so that upon rotation of the sleeve 17 by means of a wrench or other suitable tool the body 10 will also be rotated.

In assembling the parts of the plug, the insulator 18 is provided with a gasket at each side of its enlarged cylindrical portion, the lower gasket serving to seal the joint between the upper inclined or flared end'o'f the body 10 and the shoulder 15 of the insulator, and the upper gasket being adapted to seal the joint between the complementary portion of the sleeve or shell 17 and the inclined portion 14 of the insulator. The parts are placed between rotating

spindles

23 and 24, which are shown in dotted lines in Fig. 2, and force is applied for pressing the sleeve 17 upon the body 10 of the plug for uniformly compressing the gaskets 21 after which a roller 25, shown in dotted lines in Fig. 3, is applied against the thin lower portion of the neck or reduced lower end of the sleeve 17 by means of which the said sleeve is spun or rolled into the annular channel or slot 20 around the body of the plug. This rolling operation causes the thin ortion of the sleeve or thread as it enters t e channel 20 to become elongated and fit tightly between the sides of the channel or slot which causes a tight joint with the interior of the sleeve snugly engaging the knurled surface 22. Pressure applied for forcing the sleeve or shell 17 upon the body 10 is only in an axial direction and the insulator is held in place solely by such axial pressure while at the same time the rolling is accomplished in spaced relation to the enlarged portion of the insulator, thereby practically eliminating the breakage of insulators in manufacture as well as the elimination of localized stresses on the insulator while at the same time the gaskets are subjected to sufficient pressure so that there is practically no chance for leakage around the same.

It will be obvious to those skilled in the art thatvarious changes may be made in my device without departing from the spirit of my invention, and I, therefore, do not limit myself to What is shown in the drawings and described in the specification, but only as set forth in the appended claims.

Having thus fully described my said invention, What I claim as new and desire to secure by Letters Patent, is:

1. A spark plug comprising a body having an inclined upper extremity, an external an nular channel below said extremity, a f "ket resting on the extremity of said bod an insulator having an enlarged portion resting on said gasket, a gasket disposed on the opposite side of the enlarged portion of the insulator, and a sleeve having an internal flange resting on said last mentioned gasket and having its opposite end spun into said annular channel on said body, substantially as set forth.

2. The process of making aspark l g comprising telescoping a sleeve over the bony of a plug, to compress an insulator therebetween, pressing said parts together in an axial direction, and spinning the inner end of the sleeve tightly into engagement with the body of the plug, substantially as set forth.

3. A spark plug comprising a min body having one end threaded for engagement with a cylinder wall and having its other end inclined for engagement with a gasket, :1 channel formed about said body, an insulator resting on the upper end of said body, a sleeve engaging said insulator and having a reduced portion fitting snugly about said body, substantially as set forth.

at. lhe process of making a spark plug comprising telescoping a sleeve over a body of the plug, with an'insulator tlierebetween, pressing said body and sleeve together in an axial direction and rolling the teleseoped end of the sleeve tightly into engagement with said body, substantially as set forth.

5. A. spark plug comprising a body having its lower end portion formed for engagement with a cylinder wall, an insulator extending through said body, a sleeve engaging said insulator and secured on said body, said body being provided with an annular reduced knurled portion, said sleeve llttVlllg a reduced annular portion disposed in said annular knurled portion, substantially as set forth.

in witness whereof, I have hereunto set my hand at Andrews,lndiana this th day of May, A. D. nineteen hundred and twenty-