US1648770A - Spark plug - Google Patents

Description

Nos?. s, 1927.

M. JACOBS SPARK PLUG Filed March 2, 1926 Mam Z@ @0056;

@Mummia enemies Nev. s, i927. f

1,948,779 PATENT FFCE.-

MURICE JACOBS, 0F TUCSON, ARIZONA.

SPARK PLUG..

Application 1ed March2, 1926. Serial No. 91,763.

rihe invention relates 'to improvements in spark plugs for internal combustion engines, and it is my object to provide a new and improved plug construction, in which novel provision is made, permitting the electrodesV p of Fig. 1.

I illustrates one advantageous constructiom. and this construction 'will be here-1n spe-l Fi 3 is a horizontal section on line 3-3 of Figs. 1 and 2. While the drawing above briefly described,

citically described, it is to be understood at the outset, that Within the scope of the invention 'as claimed, numerous variations may be made.

The numeral having the usual flat-sided.' portion 5 for engagement with a Wrench, and cylindrical,

externally threaded portions 6 and 7 pro-I jecting in opposite directions from said portion 5, the portion-6 being adapted for reception in the usual spark 'plug opening of Aa. cylinder head, while the portion 7 is received Within a continuous shell cap 8. 'The shell body 4 and the cap 8 are so shaped as to effectively secure an insulator 9 inplace,

` the usual gaskets 10 being employed.

The shell body 4; is divided on lines 11 extending` longitudinally thereof, into two co-operable sections 12, which sections are held together by the shell cap 8 and by the.. cylinder head, when the spark plug is threaded into the latter. To assist in assembly,- the sections 12 may be provided with anydesired positioning means,` such as intertitting tongues and grooves 1ER-14.

A grounded electrode'l is provided,'hav

ing an attaching portion 16 which is tightly held between the sections12, but-is readily f removable when these sections lare separated from each other by 'unthreading the plug 'from the cylinder head and removing the shell cap 8. `The attaching portion 16 is shown in the form of' a wedgeshaped head,

4 designates a shell body and opposed surfaces of the sect-ions l2 are formed With angular notches 17 snugly receiving said head.' These notches open through the inner end of the shell portion 6, through the-.exterior of this lportion and through the interior thereof, in the present disclosure. Hence, the shell andthe attaching portion 16 are pro-vided with cooperablemeans to hold said portion 16 against movement toward either the exterior or the interior of the shell. These cof-acting means may Well consist of Vstuds 18 on the attaching portion 16, and sockets 19 in the shell sections 12, said sockets receiving. said studs.

Preferably, the free edge of the shell portion 7 is formed With notches 20 at the ends of the lines 11, facilitating the insertion of a knife blade or the like to separate the shell sections 12, if they havefbecome stuck toget-her by carbo-11 o-r the like, after along period of use.

A metallic memberis embedded longitudi-y nally -in the insulator 9 and embodies a tubu lar inner portion 21, an outer portion 22 extending yto the outer end of the insulator land constituting a'binding post, andv an enlargement 23 Withinthe portion ofthe insulator surrounded by the heavy intermediate portion 5 of the shell body i,the three'portions 21, 22 and 23 being preferably integral With each other as shown.

' The tubular .portion 21 extends t0 theinnerend of the insulator 9 and is gradually increased in' diameter toward said end. A central electrode 24 is snugly received in this tubular portion 21, being` vlongitudinally ta ered both for 'tight wedging engagement wlth said tubular portion, and to provide the electrode vwith an enlarged portion which projects beyond the insulator and is provided with fiat surfaces 25 to be engaged by a Wrench or other suitable tool. threads-26 are provided for connecting the smaller end of the electrode 24,- with the portion 23 of the metallic member 21-22-23'.

Screw- By using a wrench or the like' up0n the fiat l faced portion of this electrode, it maybe tightly threaded and wedged. into operative position so that there is no danger of it becoming accidentally detached. Whenever the sparking point 27 o f this electrode has become so Worn as to be ineicient, the portions 25 may be engaged with a Wrench or the like and the entire electrode removed. Then, a new electrode may be substltuted.

As the wear on bo-th electrodes 2415 1s uniform, both of them should be renewed at the Sametime, but this may not in all instances be necessary.

Itwill be seen from the foregoin that I have provided a new and improve spark plug lconstruction in which the majority of parts may be used throughout the life of the machine on which it is employed, unless breakage of the insulator 9 should' acciden-v tally occur. The electrodes however, may be renewed from time'to time and after such renewal, the plug isjust as eiic'ient as a new u Attention is again invited to theI fact that within the scope of the invention as claimed various modifications may be made.

I claim the following as newly invented with respect to spark plugs 1. A spark plug comprising a shell externally threaded for engagement -with the usual spark plug opening of a cylinder head,l

between said abutting edges'of said sections,

said additional electrodel being removable upon separation of said sections.

2. A spark plug comprising ashell body externally threaded for engagement with the usual spark plug opening of a cylinder head, said body being -divided into sections meeting on lines crossing the screw threads, an

.insulator removably held between said sections and carrying an electrode, a shell cap threaded upon the outer end of the shell body and holding said sections against sepan ration prior to threading of the plug into the opening, and an additional electrode free of connection with said insulator and lhaving an attaching portion rigidly held between said shell sections, said additional electrode being removable upon separat-ionof said sections after removal of said cap.

3. A structure as speciied in claim .1;

said attaching portion of the electrode being inthe form of an enlarged head, said abutting edges 4olf said shell sections being rek cessed from the interior to theexterior of the shell to receive said head, said head and shell vhaving co-acting" meansy to prevent .movement of said head toward the interior or exterior of the shell while the shell sections remain assembled.

MAURICE JACOBS.

Images