US1358292A - Spark-plug - Google Patents

Description

I. H. COLLINS.

SPARK PLUG.A

APPLICATION FILED MAR. 8| I9|9 Patented Nov. 9, 1920.

INVENTOR. fameC'o//mx W! TNESS: @mm pb. www

A TTORNE Y.

` combustion of the gases,

UNITED STATES PATENT OFFICE.

SPLBK- PLUG.

Y '0 all whom it 'may concern:

Be it known that I, JAMES H. COLLINS, a citizen of the United States residing at Harrisburg, in the county of bauphin and State of Pennsylvania, have invented certain new and useful Improvements in Spark- Plugs, of which the following is a specilication.

The object of this invention is to provide a sparlcplug of improved design for internal combustion engines, and adapted to overcome the defects commonl experienced in other plugs, and resultinglyf recognized by increased efiiciency thereover.

After exhaustive study upon the subject of spark-plug construction and performance, certain unfailing rules have been observed regarding their general characteristics. With a given supply of electric current, and the same spark-gap is used, the spark of a plug having a single gap between a pair of electrodes is fatter, or of more intense heat than where a plurality of gaps is used.

But with a single gap, it is obvious that, as a result of anything ess than a complete a deposit occurs and tendseventually to bridge said gap, whereas, other factors being equal, the same deposit will generally take much longer to short circuit a multiplicity, care being exercised notto increase the number of the same unreasonably, and thereby develop an infinite number of sparks but with greatlydecreased ability to ignite the usual gaseous mixture. i

These are by no means the only rules which must be recognized as governing the details of spark-plug construction, but they will suliice for purposes of illustrating the care which must be exercised in designing any new departure in this class of devices. And as a result of takin construction hereina ter described in detail` has been developed, and the same has been proved to insure dependable operation under the most 'exacting conditions presented by commercialservidt.

Thuii, object of the invention is to provide a' siizrlnplug adapted to 'produce hot fat .s 'arks simultaneously across a plurality of sparkggaps; to provide means for adjusting the istances across all of said gaps simultaneously; to provide a positive electrode so constructed as to disrupt the s ark discharges therefrom in order to cause t em to penetrate and ignite the gaseous Speclcaton ot Letters Patent.

Application illcd March 8, 1919.

them collectively, the

Patented Nov. 9, 1920. semi no. 281,345.

mixtures in a cylinder with greater certainty; to provide a construction operative to permit the porcelain part or parts of the improved spark-plug to yield, as may be desired, to the ex lesions within a cylinder instead of being rigidly held in position and thereby subjected to fracturing stresses; and to provide with all acme of simplicity in the construction of the improved spark-plug its various details.

With these and other objectsin view, the invention consists in novel details both in construction and operation, hereinafter fully brought out in the following description, when read in conjunction with the accompanying drawings, in which fi re 1 is an elevation of the preferred embo iment of the invention; Fig. 2 is a vertical diametrical section of the same; Fig. 3 is a bottom plan view of the same; Fig. 4 is a section on the line 4 4 of Fig. 2; and Fig. 5 is an enlarged detail diametrical section of the central e ectrede-head.

Referring to the drawings, a metal cylinder 1 is provided, upon one end with externa] screw-threads 2, while its outer end portion 3 is provided externally with screwthreads adapted to engage corresponding threads within an aperture in the cylinder of an internal combustion engine (not shown), while connecting the main and reduced portions of said metal cylinder is a Vplain wall surface 4, functioning as hereinafter described.

Within the larger l and immediately a( ortion of the cylinder jacent to the surfe-ceti is an annular gasket 5, preferably made of non-inflammable fibrous material such as asbestos, and u on which in turn is laced an annular gas et 6 of relatively so ma teri'al such as copper. The porcelain member 7, of substantially the saine diameter as the member 1 is inserted thereintc and with a reduced end portion 8 extending into the reduced portion 3 of said member, while the said orcelain is provided thro h its enlarged portion with a centrally positioned bore 9, terminating in a larger similarly ositioned b'ore 10 passing through its reuced portion.

Extending through the bore 9 in the porcelain member 6 is a threaded stem 11 carr in a nut 12, which, cooperating with t e sidges of bore 10, revolves with respect to the said stem upon turni the latter, and thus operates to shift sai stem longitudinally through the said bores. The inner end por tion of the said stem (considering a sparkplug as when positioned o eratively with respect to an engine cylinder? comprises one of the electrodes separated by a gap, between which sparks jump for the purpose of igniting the explosive gases within the cylinder of an internal combustion engine in the usual manner.

Surrounding the stem 11, and abutting against the larger end of the porcelain member 7, is a loosely mounted washer 13, against which is pressed a radially outwardly flanged portion 14 of a non-inflammable cylinder 15, closely yet slidabl surrounding t e stemand in turn surroun ed by a cylindrical portion 16 of a second non-inflanr mable member provided with a radially outwardly extending annular flange 17, op positely positioned with respect to the flange 14, and between which flanges extends a compression coil-spring 18 surroundingr the telescoping portions 14 and 1G ol the re# `second electrode passing centrally between spective non-inflammable members.

The major portion of the spring and copcrating members thus describedare positioned within the enlarged portion 19 of a bore 20, extending respectively through an enlarged section 21and a reduced section 22 of a second porcelain-member, said sections of this member being connected b a radially extending external surface Q3 orming an annular shoulder against which bears uniformly an annular washer 24 of relatively soft material such as copper. lVith the inner parts of the device constructed and positioned as thus described, an internally threaded cap 25, provided with a central bore 2G, is then slipped over the second porcelain member and screwed firmly upon the threaded portion 2 of the metal cylinder 1.

Upon the opposite or outer free end of the stcm 11 is positioned a lock-nut 27, while adjacent thereto said stem is provided with a knurled binding-nut 28, for the purpose of rcmovabl yet firmly attaching to said stem the usualv electric conductor. Tn order to adjust the longitudinal position of the stem forming a part of this improved spark-plug, the binding-nut being loose, the lock-nut 2 is loosened, and said stem revolved in thc drection desired for the purposc of shifting its electrode section into operative position with respect to thc reduced portion Il of the member l. which reduced portion forms a. second clcctrodc. or out of this position it is free from said reduced portion for thc purpose of cleaning both electrodes.

The central electrode, which is the inner end portion of the stem 11, is made in such manner as to comprise two spaced disks 29 and 30, integral with said stem and forming at first radially extending flanges lying in parallel planes. However, these spaced disks are scalloped at spaced intervals ll in order to form between adjacent scallops blunt discharge points 32.

The oppositely disposed points of each pair are thcn brought toward each other as clearly shown in 'I1 ig. 5, so that the pointed sections, together with that part of the stem 11 connecting them, coperate to form in cross-section a horse-shoe shape, after which the extremities of said points are turned off concentrically with said stem, so that the outer surfaces of the points of each pair are in alinem'ent with each other, and thereby at all times equi-distant from the adjacent portion of the electrode section of the member l, as Well as insuring the distances being equal between each pair of said points and said portion of the second electrode.

In setting the position of the central electrode longitudinally with respect to the seeand or surrounding electrode, care is taken to so adj/ust the former as to insure the plane of the peripheral surface extremity of the the points of each ofthe pairs of points upon said central electrode, because of the fact that electric sparks universally tend to jump f'rom and toward the sharpest edges or points o'fy neighboring members of opposite polaity. Thus1 while the discharge points of the disk 25) are actually within the reduced electrode portion of the member l, sparks jump from said points to the inner edgel of the surrounding electrode, toward which edge sparks also jump from the pointed lateral extremities of the disk 3U, forming thereby a continuous spark discharge from the points of each pair to the neighboring portion of a second electrode, and addiY tionally, while the actual theory of' thc discharge may not be fully understood at this time, it is believed that the pcculiar character of the discharge is at least partially duc to the discharges from the disk 2f) to thc nearest edge of the electrode Il being disrupted or repelled to a certain extent by thc charge of the same polarity upon the neighboring points of thc disk 'lfl. ."limilarly` it appears that a discharge from the points of the disk 30 is arced outwardlyr and possesses an increased fiery characteristic, hccausc of thc. nearness of the respective oppositcly positioned points of the disk 2!) ol' thc same polarity.

Thus, this construction effects a discharge from the central to thc Isurrounding clcctrode of a considerablyl difl'crcnt cluiructcr, thc central electrode haring lhc form of a continuous disk, a geur-shaped disk pro vided with sawtccth. or a central electrode comprising onc or more discharge points cxtcnding radially therefrom, such as occurs in many wcllknown types of devices of this character.

Having thus described my invention,

what I claim and desire to protect by Letters Patent of the United States is 1. A spark-plng, comprising a casing, a porcelain seated within saidcasing, a sec4 ond porcelain within and normally seated against said casing, an electrode extending through said poreelains and normally fixed with respect to said first portion, and resilient means between Asaid porcelains, operative to permit said second porcelain to yield in accordance with explosions within a cylinder of an internal combustion en gine, and to move with respect to said electrede.

2. A spark-plug, comprising a metal casing forming one electrode, a porcelain seal seated within said casing, a second porcelain within said casing, a second electrode supported by said porcelain, and resilient means between said porcelains, operative to permit said second porcelain to yield in accordance with explosions within a cylinder of an internal combustion engine and independeutly of said second electrode.

3. A spark-plug, comprising an electrode having a pair of concentric disks, the peripheral portions of said disks being sepa rated a less distance than. their central portions.

4. A spark-plug, comprising an electrode having a pair ofa concentric disks slightly7 scalloped to provide circumferentially spaced radially extending projections co1'- respondingly positioned upon each of said disks, and the extremities of said projec tions o f each pair being closer together than the central portions ofsaid disks.

5. A spark-plug, comprising a metal casing having an annular edge portion forming one electrode, and a second electrode comprisino two spaced disks uniformly and respectively spaced away from the edge portion of said first electrode.

6. A spark-plug, comprising a metal easing having an Vannular edge portion forming one electrode, and a second electrode. positioned centrally within said first electrode, and comprising spaced disks having spaced peripheral projecting portions spaced an ecpial distance from the edge portion of said first electrode and the corres|mnding projection.

7. ln a sparlcplug. an electrode comprising a stem provided with spaced flanges, each of said flangesI Vscalloped at lintervals. to provide intermediate substantially radial projections oppositely disposed upon said flanges.

f-l. In a spark-plug. an electrode comprising a stem provided with spaced flanges,

each of said flanges scalloped at intervals to provide intermediate substantially radial projections oppositely disposed upon said flanges, the projections upon each of said flanges being directed toward the corresponding projections upon the other of said flanges. y

9. In a spark-plug, an electrode comprising a stem provided with spaced flanges, each of said flanges scalloped at intervals to provide intermediate substantially radial projections oppositely disposed upon said flanges, the project-ions upon each of said` flanges being directed toward the corresponding projections u on the other of said flanges, and the radia ly outer surfaces of said projections being in alinement and concentric with said stem.

10. In a spark-plug, an electrode comprising a stem provided with spaced flanges, each of said flanges scalloped at intervals to provide intermediate substantially radial projections oppositcly disposed upon said flanges, and a surrounding electrode surface positioned so that the plane of said surface is substantially perpendicular to the axis of said stem and intersects said stem substantially midway between said flanges.

11. In a spark-plug, an electrode comprising a stem provided with spaced flanges, each of said flanges scalloped at intervals to provide intermediate substantially radial projections oppositely disposed upon said flanges, the projections upon each of said flanges being directed toward the corresponding projections upon the other of said flanges` and a surrounding electrode surface positioned so that the plane of said surface is substantially perpendicular to the axis of said stein and intersects said stem substantially midway between said flanges.

1&2. In a spark-plug` an electrode comprising a stem provided with spaced flanges, each of said flanges scallo ed at intervals to provide. intermediate su :stantially radial projections oppositely disposed upon said flanges` the projections upon each of said flanges heilig directed toward the corresponding projections upon the other of said flanges` the radially outer surfaces of said projections being in alinement and concentric with said stem, and n surrounding electrode surface positioned so that the plane of said surface is substantially perpendicular to the axis of said stem and intersects said stem substantially mid-way between said flanges.

In testimony whereof I have affixed( my signature.

JAMES I-I. COLLINS.

Images