US1390014A

US1390014A - Spark-plug

Info

Publication number: US1390014A
Application number: US302734A
Authority: US
Inventors: Charles W Brewster
Original assignee: BREWSTER GOLDSMITH CORP Inc
Current assignee: BREWSTER GOLDSMITH CORP Inc; BREWSTER-GOLDSMITH Corp Inc
Priority date: 1919-06-09
Filing date: 1919-06-09
Publication date: 1921-09-06
Anticipated expiration: 1938-09-06

Description

C. W. BREWSTER.

SPARK PLUG.

APPLICATION FJLEQ JUNE 9, I919.

Patnted Sept. 6,1921.

CHARLES w. newsm n, new Yon x, "my, ass enon TO THE BREwsrEaqoLnsm i'rg "CORPORATION, me; aconro m'rron or NEW YORK.

sPm-rL G. I i 2 I i Application flled June 9,

To allwhobi it mag concern." Y

Be it iknown that I,

s'rnn, a'ccitizen of the United States, and a resident of 'Ne w' York, in the county and State ofcNew York, have invented anew and useful Improvement in Spark-Plugs, of

whichthe following is a specification;

My improvement relates to spark plugs. It has for its object to provide a new and improved spark plug of great durability, and one capable ofwithstanding the high temperatures and strains of high compression motors; It consists of the novel devices and combinations herein set forth. i In thejac'companying drawings forming part' of this specification 'I have shown my improvement in its preferred form, and also somefmodifications of such form.

, Referring to the drawings, Figures 1, 2

and3 illustrate a preferred form of my improvement in which Fig. 1 is, a central longi tudinal section through thespark plug, and Figs. 2 and 3 are cross-sections on the lines 22 and 3-3, respectively, of Fig. 1, viewed as shownby the arrows. Figs. 4, 5 and 6 represent central longitudinal sections through modifications.

phere, an upper chamber 6 and ailower chamber. 7. The upperlchamber 6 isformedt.

by a hollow"cylindrica-lpiece Shaving .its,

lower walls inwardly converging as at 9 to formasmallcircular opening 10 around the body of theelectrod'e- 'Piece 8 is held in place by 13 a collar.

14 is a hollow conical shaped pie e or ring made of compressible materialsuch as a soft metal like brass.) It closely surrounds the mica and is forced against it and piece 5 in the manufacture of. the sparkplug by means of the follower 11' toform a tight joint. around the spindle-to pre ent the escape of gases from the chamber 6. I I I The lower outer portion of the spark plug consists ofa body 15 provided at its. upper end with screw threadsmeshing with the corresponding screw threads on. the fol-' a follower 11.. 12 is a nut and outside toward thecentral electrode.

specification of Letters Patent. 7 Patented Sept. 6 1 2 1919. sen i ive. 302,734. 1

lower 11 andlprovided atits lower 'end' with the-usual screw threads 16. i The body 15 is closed atits lower end by metallic" walls 17 shaped somewhat like an hour glass, that is, with its lower surface sloping and upwardly from the center. There is an end of electrode 1, and the inner wall "of which forms the .second' electrode.- I electrodes may be made; of any suitable material. The hour glass piece 17 has one or more ports 23 in it,four in number, as shown inFlgs. 1 and 3. These preferablv extend upwardly and outwardly, as shown, for a purpose to beshortly described. Body 15 forms a chamber 19 surrounding the chamber 6 and intended to act as a cooling chamber. This cooling chamber may be of any suitable constructlon and may e supplied in any waywith any suitable cooling fluid. As shown, and preferably, it is an open chamber supplied with airfrom the atmosphere and for this purpose it is provided with ports 20 connecting with the atmosphere for the circulation of cooling air either naturally or under forced draft, in order to assist in dissipating the heat generated in the inner parts. Part 8 is also preferably made of some suitable metal with high heat conducting capacity such as brass, to assist inthe dissipation of heat. 2 i

' 21 is the usual cylinder gasket and-22 an integral extension or collaron the spindle 2 for supporting the mica. It will be understood that the mica istightly held and com-1 pressed between the various 1 parts of the spark plug to afford good insulation and tight joints. 7 Chamber 7 commonly called by me the The scouring chamber, is provided with surfaces trode and through the spark gap 18. These surfaces, as shown in Fig. 1, 'in addition to the side walls consist of the wallsj'24 forming the roof of the chamber. These are sloped downwardly and inwardly from the The blast passing through the'ports strikes theside walls and is thrown against the slop-.

ing walls 24, and is by them deflected downa d wa gain t e tr d d;

so outwardly and downwardly from the center, and 1ts upper surface sloping outwardly through the spark gap. This tends to scour or keep clean both electrodes. The rush of gas past the opening 10 tends to draw out the gas from the chamber 6, and thus tends to keep that chamber clean. The action in the scouring chamber is assisted by the lowerwalls or floor 25, which slope downwardly and inwardly to the spark gap. Moreover, the blast from the explosion through its contact with the side walls of the ports 23 and with the side and top walls of the scouring chamber, is very considerably reduced in temperature so that when it strikes the electrodes it has less tendency to heat them. In this way undue heating of the electrodes and pie-ignition are prevented.

Because of the efficiency of my improved spark plug in dissipating heat, I find that I can treat the mica with linseed oil, as by immersion in a bath of the same, without any danger of the mica, in the practical use of the spark plug. absorbing engine oil and carbon, and without any danger. of the linseed oil in the mica becoming itself carbonized. The presence ofthe linseed oil in the mica prevents it from absorbing engine oil or carbon which, as well known, would reduce the resistance of the mica to high tension current and reduce its heat conductivity. As is well understood, excessive heat tends to carbonize linseed oil in mica and this has heretofore prevented the successful use of linseed oil with mica in spark plugs for use in high speed or high com pression motors. By my improvement, however, linseed oil can be used in spark plugs for use in such motors.

The downwardly and outwardly sloping surfaces 17 projecting below the electrodes, serve to protect them and also assist in drawing oil away from them.

Fig. 4 merely represents a modification in which, in place of the cone or ring 14, Fig. 1, made of brass, I use a somewhat larger cone or ring 26 made of mica. The mica is compressed between the follower 11' and the spindle 2 in the same manner as described for the brass ring 14 and for the same purpose. In Fig. 4 also I have shown the electrode 1 as enlarged at its lower end 27 so as to form a larger circular spark plug.

Fig. 5 represents a modification in which I have dispensed with the cooling chamber 19 of Fig. 1, and substituted in its place exterior radiating projections, shown in Fig. 5 as ribs 28. Fig. 6 is like Fig. 5 except that it omits the radiating projections 28.

My improved spark plug, especially in its preferred form, is peculiarly well suited to the engines of high compression motors as it is able to withstand the strains and high temperatures encountered in such engines. It dissipates t e heat rapidly, the electrode surfaces are kept bright and clean, and the parts kept ineflicient condition, so that the spark plug, even under the most trying conditions, 1S durable or has long life, and 1s veryefficient.

In the form of my improvement shown in the drawings, Fig. 1 is the most ctlicient and is best adapted for high compression motors such" as Libe'rty motors, and other motors encountered in aviation, where the heat developed is very great. Fig. 5 represents the form next efiicient, and is adapted for aeroplanemotors of less power where the heat developed is less in amount, and that shown in Fig. 6 is adapted more especially for automobile engines where the heat developed is considerably less.

Between the lower section of mica and the lower surface of the follower {11 imme diately above it. I preferably leave a small circular space shown at 30 in Fig. 1. This circular space surrounds the lower part of the piece 14. I find that in practice the continued poundings of the explosions on the lower part of the spindle tends to force up the brass ring 14, and thus loosen the joint between the mica and the spindle. I have found that this trouble can be obviated by providing a small gap such as shown at 30 in Fig. 1. The hammering of the explosions, when such a gap is present, causes the lower part of the mica toforce the brass piece slightly upward tending to keep the joint tight at all times.

lVhat I claim as new and desire to secure by Letters Patent, is:

1. In a spark plug the combination of an electrode, a chamber surrounding the elec trode near its end, having surfaces comprising its roof, floor and walls, inclined to one another and adapted to receive blast from the explosion and deflect it inwardly and downwardly against the end of the electrode and through the spark gap, and ports through the floor of the chamber connecting the latter with the cylinder when the spark plug is in position, and inclined so as to admit the blast from the explosion in the cylinder into the chamber and to direct it against a portion of the said inclined surfaces of the chamber, whereby blast from the explosion will be admitted into the chamber and be deflected inwardly and downwardly against'the end of the electrode and through the spark gap.

2. In a spark plug the combination of a central electrode, a chamber surrounding the electrode near its end having surfaces comprising its roof, floor and walls, inclined to one another and adapted to receive blast from the explosion and deflect it inwardly and downwardly against the end of the electrode and through the spark gap, the floor of the chamber having near its center a. ring electrode surrounding the end of the central electrode, and para through the floor ofthe chamberconneeting the latter I with the cylinder when the spark plug is in position, and inclined soas to admit blast from the'explosion in the cylinder'into the chamber and to directitoagainsta portion of the said inclined surfaces of the chamber,

whereby blast from'the explosion will. be

I; spark gap.

3. In a spark plug the combinationof central pin electrode having a" cylindrical body of. relatively large size and a reduced end portion of relatively smalls i zeat the spark gap, alchamber surrounding the-electrode near its end havingv surfaces compris- P ing its roof, floor and walls, inclined to one another and adapted, toreceive blast from the explosion "and deflectf'it' inwardly and fdownwardly against the end of t e elec; trade and through the spark gap, the floor of the chamber. having near its centeraring electrode surrounding the end of the. central V electrode,'and ports through the floor of the chamber connecting the latter with the cyl:

'' inder when the spark plug is in position, and

inclined so as to admit blast from the explosion in the cylinder into the chamber and to direct it against ,-a .portion offthe said in clined surfaces. of the chamber, whereby blast from the explosion will be admittedinto the chamber andbe deflected inwardly and downwardly against the end of the central electrode and through the sparkgap' 4. In a spark-plug the combination of a central electrode, a chamber surrounding the electrode, thefloor of the chamber formingnear its center a ring electrode surround ing the end of the other electrode, ports extending upwardly and outwardly through central electrode, a chamber surrounding the electrode, the floor of the chamber form- ;ing'near its center a ring electrode surrounding the end of the other electrode, ports extending upwardly and outwardly through the floor of the chamber adapted, when the spark-plug isin position, to admit blast from the explosion into the chamber and deflect it against the outer side walls of the chamber,and surfaces in the chamber sloping downwardly and inwardly to receive and deflect said blast against the central electrode and through the spark gap.

6. In a spark-plug an electrode, a chamher surrounding the electrode closed to the atmosphere, ,an outer cooling chamber surroundingthe closed chamber and provided with ports opening into the atmosphere.

7. In a spark-plug the combination of a central electrode, a cooling chamber, closed to the atmosphere, surrounding the upper portion of the electrode, and having its walls converge" inwardly and downwardly to leave a small air gap between them and the electrode, a chamber surroundingthe lower portion of the electrode and having its upper walls slope downwardly and inwardly to said air gap, and provided with ports its lower walls adapted, when thesparkplug is in position, to admit blast from the explosion into the chamber, whereby the blast will be forced downwardly and inwardly against'the electrode and past the said air gap and will thereby draw gas downwardlylfrorn the cooling chamber.

8. In a spark-plug the combination of'al central pin electrode, and a surrounding, metallic piece having an opening at the center for the pin electrode, said piece having its'lower surfaces sloping downwardly. and outwardly, and its upper surface sloping upwardly and outwardly.

'9. In a spark-plug the combination of a central metallic spindle, insulating material surroundingthe upper part of the spindle, and'a ring of soft'metal compressed around the insulating material to make a gas-tight joint around the spindle. 1 a i 10. In a spark-plug the combination of a central metallic spindle, insulating material surrounding the upper partof the spindle and a ring of soft heat-conducting metal compressed around the insulating material to make a gastight joint around the spindle and aid in dissipating heat.

11. In a spark-plug the combination of a central metallic spindle, insulating material surrounding the upper part of the spindle and a ring of compressible material compressed around the insulating material to make a gas-tight joint around the spindle.

12. In a spark-plug the combination of a central electrode, a cooling chamber, closed to the atmosphere, surrounding the upper portion of the electrode and having its walls converge inwardly and downwardly to leave a small air gap between them and the electrode, a chamber surrounding thelower portion of the electrode, ports through the floor of the latter chamber extending upwardly and outwardly, to admit blast from the ex plosion into the chamber, and surfaces in said chamber adapted to direct thecblast downwardly and inwardly against the electrode and past the said 'air gap, whereby gas will be drawn from the cooling chamber and the surfaces of the electrodes will be cleaned and cooled. V 7

13. In a spark plug the combination of a central electrode, a chamber surrounding the upper part of the electrode having walls, made of a substance of high heat conducting capacity, converging inwardly and downwardly to leave a small air gap between themand the electrode, an outer cooling chamber provided with ports opening into the atmosphere and surrounding the first mentioned chamber, a scouring chamber surrounding the lower part of the electrode, ports through the floor of said chamber extending outwardly and upwardly and adapted to admit blast from the explosion into the scouring chamber, and surfaces in the scouring chamber shaped so as to direct the blast inwardly and downwardly against the electrode and through the air gap.

1a. In a spark plug the combination of a central electrode, a cooling chamber closed to the atmosphere surrounding the upper portion of the electrode and having its walls converge inwardly and downwardly to leave a small air gap between them and the electrode, a scouring chamber surrounding the lower portion of the electrode, and means for admitting blast from the explosion into the last mentioned chamber and directing it inwardly and downwardly against the electrode and through the air gap between it and the other electrode.

15. In a spark plug the combination. of a central spindle, insulating material sur-' the cone'shaped ring, and a lower section of insulating material surrounding the spindle and abutting against the lower end of said ring, the said insulating material and the said follower being so shaped'and arranged as to leave a circular gap between their up per and lower surfaces. v

16. In a spark plug the combination of a central spindle, insulating material sur rounding the upper part of the spindle, a cone-shaped ring of soft heat-conducting metal compressed around the insulating material to make a gas tight joint around the spindle, a follower with sloping walls fitting around the cone-shaped ring, and a lower section of insulating material surrounding the spindle and abutting against the lower end of said ring, the said insulating material and the said follower being so shaped andarranged as to leave a circular gap between their upper and lower surfaces.

17. In a spark-plug the combination of a central pin electrode and a surrounding circular electrode having an opening at the center for the pin electrode, said central pin electrode having a cylindrical body of relatively large size and a reduced end portion of relatively small size projecting into the opening in the surrounding electrode to form a spark gap and said surrounding electrode having surfaces sloping upwardly and outwardly from the spark gap, and surfaces slipping downwardly and outwardly from the spark gap. 7

In testimony whereof, I have signed my name to this specification.

CHARLES BREIVSTER.