Патент USA US2118251код для вставки
May 24, 1938. 2,118,251 E. F. KOEHLER ET AL SPARK :PLUGV Filed ~April 9, 193e m. ,Q1 a f# . m; ¿Éfgv /// Im 2.118.251. Patented May 24, 1938 UNITED STATES“ li’A'rl-:NTv OFFICE 2.11:;,251 smal; PLUG . Emma Koehler, Berlin, and Gustave w. ‘ Goerner,Bourne,_Mass. ` Application April 931936, Sel'lill No. 73,452 6 Claims. (Cl. 123-169) i ` - diameter and threaded to enter the usual thread ed hole in the casing ofthe motor. -The bore! of the casing VI tapers slightly in a portion of its Our invention relates to spark plugs for in ternal combustion engines and has for its prin cipalobject to provide an improved negative or ground electrode and means for mounting the extent, as mostI clearly shown in Fig. 4, thereby providing a seat for a correspondingly tapered 5 ` 5 same, so that this electrode may bevreadily re placed and renewed when partly burned away or distorted by use. A further object has been to provide a ground electrode which shall cause the spark to be spread and distended so that it may portion of the porcelain insulator 4. The upper -part of the insulator 4 is of uniform, reduced di ameter aiîording an annular shoulder 5 against which is seated the threaded extension of the jam nut 6 which is screwed 4into the threaded top of l0 l0 perform its function more emciently. the bore 3 of the casing I,- thereby pressing the Our device may be best understood by refer tapered portion of the insulator 4 into iirm en ence to the accompanying drawing in which: Fig. 1 is an elevation of our improved spark , gagement with the tapered _portion of the bore _3 ` plug. 15 l of the casing I. » Fig. v2 is a vertical section through the 'plug of - The insulator 4 is provided with a central bore 'l5 ì in which is inserted the positive electrode 1 the top of which is press-ñtted into hole I in thevention in which the removable'ground electrode base of the metal insulator cap 9 the cylindrical instead of being curved in an arc below the end portion I0 of which is_ screw threaded to -engage threads in the top cavity of the insulator 4. .o 20 of the positive electrode, asin Fig.'1, is curved in screw A binding post II, integral with the cap 9 is an arc laterally disposed with respect to the end of the positive electrode; the lower part of the ' screw threaded to receive the conventional shell and insulator core being shown in vertical, knurled binding nut I2 for attaching thev high Fig. 1.. „ ' ‘ Fig. 3 shows a ilrst modified form of our in medial cross section. 25 . Fig. 4 is an- enlarged section of the lower por tion of the shell showing the grooves wherever a ground electrode may be removably mounted. Fig. 5 shows in section the shell of Fig. 4 with Athe ground electrode of Figs. 1 and 2 mounted 30 therein and the insulator core and positive elec trode in place. ~ .v tension wire. " ‘ The interior of the threadedextension 2 of the 25 casing is provided with opposite grooves» I3 which enter an annular groove I4 located immediately- below the narrowest part `of the tapered bore 2 of the casing I. Within these grooves I3 and I4 is removably mounted the steel wire ground elec- 30 trode I5 which may be inserted in place when ' 'the insulator 4 has been removed and will be> locked in place by the insulator when the insu Fig. 6` is an enlarged cross-section on line 6-6 of Fig. 3, with the insulator core removed. Fig. 'I is a cross-section on line 'l--1 of Fig. 5 - lator is returned to position as shown in Fig. 5. As will be more readily understood frqm an ex- 3:, 35 with the insulator core removed. amination of Fig. 11 the~ electrode I5 is generally Fig. 8 is an enlarged section on line l-l of Fig. ' re-sl‘iaped andprovided with straight upwardly 3 with the insulator core removed. Fig. 9 shows in cross-section corresponding to that of Fig. 6 a secondmodifled form of our in ¿o vention wherein appear two removable ground extending -parts or legs which are slightly spread electrodes each organized and removably mounted the are tops slightlypressed of the straight together upwardly to permit extending insertion within the' extension 2, be forced withviirrn'spring' tension into engagement with the ground part I4 like the other on its `respective side of the end of the positive electrode. ' apart so that the free ends of the legs which take the form of curved lateral arms- I8 may„after 4o Fig. 10 is an enlarged bottom view- of the spark of the casing I when the straight upwardly ex- 45 . 45 plug shown in Fig. 1. Fig. 11 is a.v perspective view of a removable tending parts of the electrode I5 are entered in _,f. ’ ' 2 ground electrode suchv as is shown in Figs. 1` grooves lß'and ñrmly seated there. The lower central part I1 of the ground elec and 2. , Fig. 12 is a cross section corresponding to Fig. trode I5 is preferably given a substantially reg-v u 6 showings third modii‘led form inv which a pair ular arc of curvature centered on the middle of ‘ 5o I the tip of the positive‘electrode l; and, asshown of parallel- removable ground electrodesl are ern ployed.y ~ ~ _ » Referring now to the'. drawingfin which like invFigs. 1„ 2. 5,'7, 10 andy 11, this arc of curvature may be vertically disposed beneath the tip of the electrode 1, or, as shown in Figs. 3, 6 and 8 this ' reference numerals indicate like parts, `l yis a “_ shell provided with an extension 2 _of reducedy arc I1 may bev laterally disposed with respect to ß 9,118,951 the tip of the ground electrode which, as shown 4 lowerr end and provided with an annular `groove in Fig. 3, may be slightly extended for this pur and with oppositely placed straight grooves com municating with said annular groove. a generally In a modiiied form of our invention, such as ' U-shape ground electrode the legs loi' which ilt 5 that shown in Fig. 9, a pair of oppositely placed within and engage said straight grooves and the 'ground electrodes each formed with a laterally central portion of which is arranged to underlie disposed arc I1' may be employed, the ares being pose. ' and bridge across said bore and form a spark gap oppositelypositioned so as substantially to sur between said central portion and a positive elec round the end of the Y,positive electrode 1. In trodefthe free ends of the legs being bent to llt 10 this form oi construction lthe vertical grooves Il'. within the annular groove, a: positive electrodo l0. corresponding to the grooves Il of Fig. 6 are made wider to accommodate the pair oi' ground electrodes and the curved arms il' extend toward and an insulator for said positive electrode adapt ed to ilt within said bore and to retain the ends f' of said ground electrode within said annular~ each ~other instead of extending in opposite direc _1.-, consumidas. ' groove. 3. A spark plug according to claim 1 in which 16 A further modiiied form appears“ in Fig. 12 a pair oi' ground electrodes it* each`organized in the central portion of the bridge between the legs -the general manner heretofore described except of the ground electrode is bent to 'forman arc of a circle which is centered with respect to the that the vertical slots I32 wherein each is mount end of the positive electrode, the arcuate central I' 20 ed are not diametrioallyopposite each other but -portion to the legs by generally so arranged that the two ground electrodes i5’ radially being’connected disposed bridge portions. ’ ~ bridge straight across the base ofthe casing l 4.v In a spark plug the combination 'of_ a casing parallel to each other'and upon oppomte sides of the positive electrode ‘I so as to form double provided with a bore which is cylindrical at its 25 spark gaps, and the arms I6’ of each of theseß lower end, a positive electrode centrally mounted ground electrodes, like those'shownl in Fig. 6 in _said bore, an insulator for said positive elec trode, a pair of negative electrodes mounted in previously described, extend toward each other.l said casing in a manner whereby they may bridge From theï foregoing description it will be « readily understood that our removably mounted 30 ground electrodes may be quickly and easily re placed when they become’burned out or distorted _ by use, and that while in place they will maintain at all times an extensive, firm, spring pressed contact withA the _shell or casing o_l' the >plug so as' 3_5 to aiiord a good electrical connection. ’I'he arc I1 or i1' oi' the ground electrodes being substantially'a part of a true circle centered on~ across said bore, said electrodes lying upon op posite sides of the extremity of said positivev electrode in a parallel manner, said insulator maintaining said'negative electrodes in proper op erative spaced 'relation to the positive electrode. ~ 5. In a spark plug the combination of a casing provided with a bore which is cylindrical at its -lower'end, a positive 'electrode centrally mounted . in said bore, an insulator for said positive elec-Y , the axis of the positive electrode will result in a ‘ trode, there being an annular groove in the casing ` broad, fan shaped spark giving excellent ignition; opening into the'cylindrical bore, a pair oi’ gen ‘a and where the parallel arrangement of cross erally U-shape negative electrodes mounted in ' members oi' Fig. 12 is employed the cross members ' may be, if necessary, slightly pinched together and permanently distorted to compensate for the burning away o_f adjacent areas ofthe podtive ¿5 and ground electrodes which has too much widened the spark gaps. y , . Having thus fully described our invention what we claim is: - ' l. In a spark plug the combination of a casing ' 5o. provided with _a bore which is ,cylindrical at its end and provided with> a cavity opening into the . cylindrical bore, there being a groovein the cas~v lower end and provided with an annular groove, a ground electrode the ends of which _arebent to ' form arcuate portions adapted to ilt within and engage said groove and the ¿central portion oi 55 which is arranged to underlie and bridge across said bore- and form a spark gap between said central portion and a positive electrode, a positive electrode and an insulator for said positive elec trode adapted. to nt within said bore Rnd t0’ retain .o the ends of said~ ground electrodewithin said 8l‘00ve. . 2. In a spark plug the‘combination of a casing ' provided with a bore which is cylindrical at its ‘ .said casing, the‘free ends of the legs of each U v40 ,shape electrode being bent towards one another to form arcuate portions which ñt withinY the groove, said negative electrodes having portions which bridge the legs thereof to lie upon opposite sides of ,theyextremity oi' said positive electrode in oppositely extending similar arcs centered about .45 the end of said positive electrode. 6. In\a sparkplug the combination of a cas-l ing having a bore which is cylindrical at‘its lower ` ing extending from the cavity longitudinally ci' the bore to the outer end thereof, a ground elec trode in the form-oi' a wire ntted into the groove and having an end bent-to nt into said cavity, a positive electrode andan insulator for said posi tive electrode, said insulator extending down wardly into the cylindrical borey to Vengage the ground electrode and prevent movement thereof in said cavitî1 and groove. , > l ERNEST F. Komm GUs‘rsvE W. comm. '