US3079453A - Spark plug - Google Patents

Description

Feb. 26, 1963 w. v. CLARK 3 ,079,453

SPARK PLUG Filed fiov. s, 1960 1.752 V CLHRK INVENTOR.

ATTOR N EY United States Patent 3,79,453 Patented Feb. Zfi, 1933 thee 3,979,453 STPARK PLUG Walter V. Clark, 3064 W. Pico Blvd, Los Angeies 6, Calif. Filed Nov. 3, 1969, Ser. No. 66,353 3 Claims. (1. 123-169) This invention relates to an improvement in the operation of park ignition engines, and more particularly to a novel method and device, exemplified by use of a conventional spark plug easily modified as herein described, for more completely burning the engine fuel by automatically dispersing into the mixture of air and suspended or vaporized fuel-such as a petroleum derivative typified by (compounded) gasoline-a vacuum-balancing quantity of combustion promoting vapor such as external air or oxygen. At least the initial pro-ignition quantity of air is desirably metered as by selection of inlet diameter and the length of flow is automatically determined by response to vacuum suction from the combustion chamber.

By the present invention, two very observable results are obtained. First, the introduction of air into the combustion chamber at the pro-ignition phase of the piston stroke reduces oreliminates the need of the piston to overcome or act against this progressive vacuum in the chamber, thus Very appreciably increasing the effective horsepower (or gasoline milage as one may choose to regard it). Secondly, by effecting a more complete-combustion oi: fuel and its partial decomposition products, the deposition or emission of soot and smoke is decreased or eliminated. This latter contributes greatly to the reduction of smog in the atmosphere, which is attributed in large part to the engine expulsion of olefins and other unburned components. In addition, it has been observed that in an engine already burning oil or containing a carbonaceous deposit from oil or fuel in the cylinders, such existing deposition may be substantially decreased or elimi nated by use of the present device or method, so that even after a few hours running, for example, an old automobile may cease to smoke, choke and backfire and will run without the previous audible ping. Alternately, an engine may be satisfactorily operated on a lower grade fuel; for example, white gasoline or even naphtha or other petroleum (or analogous) fractions may be used in place of highly refined, blended and leaded gasoline. The overall result is both decreased engine wear and increased power or gasoline milage, while at the same time reducing pollution of the atmosphere.

Use of the present approach for control of air pollution resulting from engine exhaust, may be contrasted with the suggested. employment of absorbents or filtering devices on he one hand, or of afterburners on the other hand. Both of these are intended to act upon fuel decomposition products before they are vented, but after they have cooled down from the maximum combustion temperature of the engine. However, if more complete combustion is the desired result, it should be realized that this is best efiectcd at the highest combustion temperature which is in the engine; therefore this result is achieved by the present invention by the introduction of more oxygen to the greatest hot spot namely the combustion chamber, rather than trying subsequently to treatat a cooler temperature-the incomplete combustion products issuing therefrom. Accordingly, excessive treatment need not be resorted to for removing the last traces of undesirable components from fuel when they can be used and rendered innocuous by the present more complete combustion, which method is effective as Well against the partial combustion products initially produced in and previously often ejected from the combustion chamber.

Accordingly the objects of the invention include the provision of means for automatically admitting a desired quantity of air or the like to a spark-ignition chamber at a predetermined phase of the compression-expansion cycle so as to promote or sustain more complete fuel oxidation without unbalancing the piston cycle or engine operation.

Another purpose is to reduce the vapor pull or opposition within the combustion chamber which acts contrary to the piston movement and consequently has to be over come thereby with a corresponding expenditure of energy; by the present invention the well-known chamber vacuum or suction, which opposes the initial piston movement prior to ignition, is reduced by incoming air which in addition mingles with the fuel before combustion so as to promote subsequent oxidation thereof.

A further object is to promote more complete fuel combustion by introduction of air or the like into the ignition chamber after spark-ignition has occurred, as long as the combustion chamber is capable of exerting suction upon the outside air. An additional advantage is obtainedin this post-ignition period by reason of the pro-ignition admixture of the' fuel with the added air within the chamber. 1

An important object is to accomplish such results with an automatic metering or valve unit which remains effective and long lasting at elevated combustion temperatures.

Such valve unit is associated with or forms part, of a spark plug assembly. Thus there is provided a simple and inexpensive device which can be attached toany spark ignition engine without any structural change in the latter, and the unit assembled from a conventional spark plug by means of at most very minor change in the prior construction of the plu Still another advantage arises from specific utilization of the herein described heat-resistant, ball valve operable by suction from the combustionchamber, as well as by associated structural features including an air channel formed along the threaded attachment base of the spark plug, and a resilient inner retaining ring and outer valve collar carried by the plug assembly. These elements (aside from the channel) may be formed so as to be transferrable as a unit from one spark plug to another if desired.

Another object is the provision of a compact and highly-effective unit-long lasting under high temperature operation-consisting of an apertured collar, ball valve and heat-resistant retainer ring cooperatively effec-' tive for providing a wear-resistant seal for the present purposes and readily adapted to employment with conventional park plugs.

Additional objects and advantages will become apparent as the description proceeds, having reference to the drawings which form part of the present specification, wherein FIGURE 1 is a side elevational view of a spark plug embodying my invention, with a portion of the attachment collar and inner gaskets and retainer ring broken away to show their construction in section;

FIGURE 2 is a similar view in reduced size, of the spark plug shown mounted in the firing chamber of an internal combustion engine, of which only the upper Wall is indicated in section;

FIGURE 3 is a bottom plan view of the spark plug of PEGURE l as seen along the line 33:

FIGURE 4 is a plan view of the resilient retainer member removed from the spark plug and attachment collar; and

FIGURE 5 is a fragmental, transverse sectional view through the attachment collar and adjacent structures as viewed along the line 5-5 of FIGURE I, particularly showing the ball valve held in operative position between the retainer member and the tubular insert in the collar.

The invention is here illustrated in connection with the basic structure of a conventional spark plug, indicated generally at 19. A longitudinal electrode extends centrally thru the'unit from an outer terminal 12 which serves as an attachment post for an electrical contact or wire '14 (coming from a power source by way of a timing mechanisrnnot shown), the electrode passing downward through a surrounding, generally tubular externally convoluted, insulating neck 16, typically of porcelain, then through a radially enlarged housing body 18 formed with an outer, circumferentially projecting series of fiat, lateral surfaces 20 (typically six in number) adapted for frictional engagement by a hex socket wrench (not shown) 7 when mounting and demounting the unit from an engine block22 or the like. The electrode then traverses a lower insulating tube 24 which itself is centered within and projects beyond the end of an externally threaded (metallic) attachment plug 26, by means of which threaded plug the unit is removably mounted in a correspondingly threaded aperture 28 of the engine block 22, so that the p oje'cting' electrode tip 30pis thus located within the corn: bustion' chamber 32 thereof. In the well known manner, a sparkfrom the electrode tip 30, at timed intervals leaps the gap 34'to the opposing or overlying receptor tab or conductor arm 36 which projects from the metallic attachment plug 26 and is accordingly grounded to the engine block. The overlying end of the contact arm 36 which is spaced from the electrode tip 30, can be bent (when removed from the engine) so as to vary. the distance of the sparkgap 34 in accordance with the requirernentof the particular motor. An annular gasket 38 such as a deformablermetallic O-ring, conventionally provides a mounting seal between the outer face of the engine block surrounding its socket aperture 28 and the outwardly extending portion of the unit 10.

In'applying the invention to the above described spark plug, first there is formed a longitudinal or generally axially directed, open channel or groove 40 extending along the whole length of one face'of the attachment plug 26 transverse to the encircling threads. At the housing end of the threaded portion is a generally cylindrical or smooth, circumferentially restricted section 42, analogous to a raceway, having a radius equal to the depth of the groove 40, and terminating in a more-or'less perpendicular or slightly undercut (i.e. upwardly converging) abutment face 44 which forms the bottom flared wall of the housing body 18. This constitutes the extent of the essential structural alteration to the conventional unit 16 itself, aside from subsequent additions thereto as about to be described.

For disposition about the internal neck 42, there is provided a tubular collar 46, both inner and outer walls of which may be generally cylindrical, or conveniently the exterior wall 48 may be frustro-conic for ease in mounting on the unit 19. Downward from the upper edge of the collar, along'the inner surface thereof is formed an annular step or groove 59, (FIGS. 1 and having a diameter correspondingapproximately to the cylindrical housing body 18 so as to receive its lower edge inserted part way therein. Compressed within the groove 50, between the housing 18 and the floor of the groove is an annular sealing gasket 54 conveniently formed of copper or the like,

and shaped like a lateral V in radial section.

The main, inner surface 56 of the collar 46 is cyhndri cal and spaced radially outward a'small distance from the encompassed, parallel, cylindrical wall of the recess 42, andwithin this annular space is located a resilient, re-

taining element or ring 58 (FIGURE 4). The latter, typically a split ring, is formed of heat resistant, alloy steel andprovided with an outward-facing concavity or transverse socket groove'60 located adjacent one extremity and immediately terminal to a more-or-less straight segment or cho'rdal portion 62. In use (as about to be explained), therh'ain transverse line or span which bends during the resiliency is at the farther and of this chord, indicated at 64, FIGURE 4. Thus the ring, or at least the chordal portion 52, is capable of limited radial movement between the spaced upper gasket 54 and a correspondingly located lower gasket 33, the end of the ring vibrating within the annular space between the cylindrical surface 56 of the collar and the corresponding or opposing wall 42 of the plug. If desired, the lower gasket 38 may be the same V-shape as upper gasket 54.

The radial oscillation of the chord 62 occurs as result of vacuum suction from within the combustion chamber 32, acting through the passage 49, to momentarily unseat a freely rotatable sphere or valve ball 68 from its seated position normally closing a lateral aperture 7 t) in thecollar. The ball 63, generally housed within the collar 46, has one side in continuous contact with the outwardly pressing, supporting socket or groove 60 of the resilient retainer ring, which ring accordingly requires a predetermined vacuum or suction to overbalance it and open the valve. As soon as this pressure is reduced by inflowing air breaking the vacuum, the tension of the spring segment 62 presses the ball back to close the aperture and block vapor flow in either direction. Balls of stainless steel and p the like are preferable and it has been found that by use of a tubular insert 72 mounted in the collar aperture so that its inner end serves as the valve seat for the a ball 63, the ball can be readily inserted through the larger collar aperture before the insert is mounted therein, and in addition, when the insert is formed of high wear and temperature resistant alloy, the body of the collar can then be of less expensive iron or steel. In contrast, if such body material where also used to form the valve seat it would soon become pitted from repeated contact with the ball valve at the high oxidizing temperatures emanating from the combustion chamber.

It will be appreciated that the operation of the herein described structure in admitting the external air in response to vacuum or suction produced in the combustion chamber of the engine, starts soon after the piston rod or cam passes dead center in retracting the piston at the beginning of the expansion stroke. During rotation of the cam shaft from perhaps 5' to 10 after passing dead center, the piston is pulling against noticeable and increasing vacuum in the chamber prior tospark ignition. This drag or resistance requires energy to overcome, thusreducing the effective or available horsepower. It is this amount of vacuum or suction which overbalances the spring tension of the ball retainer element 62 so as to permit entry of external air during this pre-ignition period. This air (or more concentrated oxygen, if desired) serves both to eliminate the back pull on the piston and to enrich the fuel mixture in the chamber. For ease in starting the engine when cold, the quantity or flow of air at this phase of the cycle should not be unlimited; an approximately 7 inch aperture is generally satisfactory forconventional spark plugs in automobiles. If a hand choke were used in starting, a larger air inlet in the collar 4-6 can be used.

a It will be evident accordingly that vacuum or suction in the combustion chamber opens the ball valve 68 and that increased pressure of fluid within the chamber (whether due to ignition or to compression by the piston) closes it. This oscillation of the spring and ball may'occur several times in a cycle and the result as already noted-- is to eliminate such appreciable amount of vacuum, which would otherwise exert a drag on the piston, in either its up or down movement. This in itself is a very appreciable advantage, quite aside from the oxidizing effect of the added air. In addition, the air introduced before ignition, has a continuing effect after ignition, in promoting more complete oxidation of the fuel to form volatile and inert end products, as well as promoting the removal and inhibiting the deposition of any sludge and carbon previousappreciated as highly desirable, it has hitherto been unobtainable in such an automatic and self regulating a manner and with so simple a mechanism which thus achieves several results simultaneously. Although the invention has been particularly illustrated by reference to a presently preferred embodiment, it will be appreciated that various modifications and substitution of equivalents can be effected within the scope of the invention as subsequently claimed.

I claim:

1. In a spark plug of the character described having attachment means for its mounting in a position of functional projection into a combustion chamber and in such position defining an air passage therealong between the combustion chamber and the exterior, the improvement comprising in combination therewith: a collar carried by said spark plug and formed with an aperture providing the exterior outlet for said passage, 21 ball valve retained within said collar in position to serve as a closure for said aperture and air passage, and also disposed within said collar, a broken ring of resilient, heat-resistant sheet metal bent into a generally annular shape having a terminal, chordal portion formed with a transverse groove adapted fric tionally to engage said ball which is thus retained between the collar and the chordal portion, and to maintain the ball in alignment with the outlet aperture of said collar, the chordal portion thus being capable of limited radial oscillation between the plug and surrounding collar in response to suction from the combustion chamber exerted through said air passage.

2. A spark plug including a generally cylindrical, ex-

ternally threaded, attachment segment adapted for removable mounting in functional projection into the combustion chamber of an internal combustion engine and the like, which segment is formed with an open groove forming an air passage extending along the edge of said cylinder transverse to said threads and adapted when the plug is functionally mounted to connect said combustion chamber with the exterior, a tubular collar surrounding the exterior end of said segment and having its interior in communication with said air passage, said collar being apertured to provide the exterior outlet for said passage, a heat-resistant ball retained within said collar in positionto serve as a closure for said aperture and air passage, and a retainer ring disposed within said collar about said attachment segment and having a heat-resistant, resilient portion forming a seat for said ball and normally holding it as a closure in said aperture.

3. The spark plug of the preceding claim 2 wherein said collar is formed with a tubular, heat-resistant insert located in said aperture, the inner end of which insert serves as a seat for said ball and is of greater inertness to high temperature and abrasion than the body of said collar.

References Qited in the file of this patent UNITED STATES PATENTS 996,410 Harpst June 27, 1911 1,493,800 Blifiert May 13, 1924 2,292,409 Steward Aug. 11, 1942 2,490,646 Murphy Dec. 6, 1949 2,646,782 Fisher July 28, 1953 2,708,428 Fisher May 17, 1955

Claims (1)

1. IN A SPARK PLUG OF THE CHARACTER DESCRIBED HAVING ATTACHMENT MEANS FOR ITS MOUNTING IN A POSITION OF FUNCTIONAL PROJECTION INTO A COMBUSTION CHAMBER AND IN SUCH POSITION DEFINING AN AIR PASSAGE THEREALONG BETWEEN THE COMBUSTION CHAMBER AND THE EXTERIOR, THE IMPROVEMENT COMPRISING IN COMBINATION THEREWITH: A COLLAR CARRIED BY SAID SPARK PLUG AND FORMED WITH AN APERTURE PROVIDING THE EXTERIOR OUTLET FOR SAID PASSAGE, A BALL VALVE RETAINED WITHIN SAID COLLAR IN POSITION TO SERVE AS A CLOSURE FOR SAID APERTURE AND AIR PASSAGE, AND ALSO DISPOSED WITHIN SAID COLLAR, A BROKEN RING OF RESILIENT, HEAT-RESISTANT SHEET METAL BENT INTO A GENERALLY ANNULAR SHAPE HAVING A TERMINAL, CHORDAL PORTION FORMED WITH A TRANSVERSE GROOVE ADAPTED FRICTIONALLY TO ENGAGE SAID BALL WHICH IS THUS RETAINED BETWEEN THE COLLAR AND THE CHORDAL PORTION, AND TO MAINTAIN THE BALL IN ALIGNMENT WITH THE OUTLET APERTURE OF SAID COLLAR, THE CHORDAL PORTION THUS BEING CAPABLE OF LIMITED RADIAL OSCILLATION BETWEEN THE PLUG AND SURROUNDING COLLAR IN RESPONSE TO SUCTION FROM THE COMBUSTION CHAMBER EXERTED THROUGH SAID AIR PASSAGE.

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