US1009867A

US1009867A - Spark-plug.

Info

Publication number: US1009867A
Application number: US61853611A
Authority: US
Inventors: George Orvill Terry
Original assignee: Individual
Current assignee: Individual
Priority date: 1911-04-03
Filing date: 1911-04-03
Publication date: 1911-11-28
Anticipated expiration: 1928-11-28

Description

G. 0. TERRY.

SPARK PLUG.

APPLICATION FILED una. 1911.

1,009,286?, Patented N0v.28, 1911.

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Q/vhw PWA Sttomwgs UNITED sTATEs PATENT oEEioE.

GEORGE ORVILL TERRY, 0F MINNEAPOLIS, MINNESOTA.

SPARK-PLUG.

Specicaton of Letters Patent. Patented NOV, 28, 1911, Application 'filed .April 3, 1911.

in the art to which it 'appertains to inalieand use the saine.

This invention relates to improvements in spark plugs for internal combustion engines and .more particularly to improvements in what inay be termed jump spark igniting plugs.

The object of the invention is to provide a simply constructed plug having a large smooth sparking surface and so constructed as to reduce the danger' of short circuiting to the minimum.

Another object of the invention is to provide a plug of this character in which the electrodes are spaced the saine distance at all points to permit the current to jump across at any point of the periphery of the center electrode.

` Another object is to provide interchange-r able electrodes by the use of which the life of the plug is greatly prolonged and the expense of providing eXtra plugsis avoided.

Vith these and other objects in view, the invention consists of certain novel features of construction, and the combination and arrangement of parts as will be more fully described and claimed.

In the accompanying drawings Figurc l represents a side elevation of a plug constructed in accordance with this invention; Fig. 2 is a central longitudinal section thereof; Fig. 3 is an inner end view of the plug; Fig. #l is a horizontal section taken on the line tw-'l of Fig. 2 looking in the direction of the arrow. F ig. is a perspective view of one of the annular electrodes detached.

In the embodiment illustrated, an externally threaded metal shell l is shown adapted to be removably secured `in the tappet hole or opening therefor in the cylinder of an explosive engine, as will be readilv understood by those'skilled in the art. This tated when screwing the saine into or from Serial No. l6185536.

the cylinder. The outer portion of the internal longitudinal bore of the shell 1 is enlarged and threaded thereby forming an intermediate annular internal shoulder 3 from which the reduced portion of the bore extends to the inner end of the shell. At its inner end this shell is preferably formed on its inner face with an annular groove 4 which is preferably V-shaped in cross section and is designed to receive the ground electrode to be described. The inner edge of this end of the shell is preferably beveled as shown at 5 to facilitate the insertion of said ground electrode.

An elongated tubular insulating plug 6 is arranged in said shell and is composed of any suitable material such as porcelain, liber, or the like. This insulating plug (S is formed to longitudinally and removably enter a bore of the shell I and to be held therein by a hollow nut 7 through which the insulating plug 'loosely `extends and which screws into the threaded outer end ofv the bore of shell l and forces the insulating plug inwardly in the. shell by its engagement with an annular shoulder 6 formed on said plug intermediately of its' ends. This nut holds the insulating plug at its limit of inward movement preferably against a packing or cushioning ring 8 seated against the shell seat or shoulder 3. This packing ring 8 surrounds the reduced inner portion of the skirt of the insulating plug'and is seated against tliedared or inclined annular exterior shoulder 9 formed -on said plug at a point below the shoulder 6". This packing may be formed of asbestos or any suitable material. The reduced inner end portion of the insulating plug G forms an annular skirt l0 arranged concentrically within the reduced portion of the bore of the shell and terminates shortof the inner end of the shell and forms an annular fluid compression chamber within the shell around said skirt which extends from the open inner end of the shell longitudinally thereof to the packing washer 8. bore of the plug G extends throughout the length thereof and the inner end of this vbore is enlarged, the side walls thereof be ing preferably flared to form a compressed fluid cavity or chamber 11 open at the inner end of the plug and forming the hollow interior of the skirt 10 terminating at the in? tei-mediate internal annular seat or shoulder l2 within the pluO'.

The longitudinal A conducting stem .or-"rod 13 screiv threaded throughout the greater portion of its length extends through the bore ofthe insulating plug 6 and projects beyond ,thev

12 of the plug to limit the outward movement of the stem in the plug. This stem 13 is held in place by a cap 16 removably fitted on the outer end of the insulating plug 6 and screwed on the projecting end of the stem 13. The outer end of this stem 13 extends some distance beyond said cap to receive certain elements hereinafter to be described.

'A shell 17 constructed of pressed. fiber or other insulating material Ytelescopically engages the upper portion of the insulating plug 6 and is exteriorly screw threaded at its lower or inner end and engages with t'he interior,- thread on the outer end of the shell 1 outside the nut 7 and is securely locked ini: position thereon by

nuts

18 and 19 secured on the outer end of the stem 13 which projects through an aperture in the outer end of the shell 17, said nuts being designed to hold the shell 17 rigidly connected Arelatively to the insulating plug 6. This shell 17 is designed to serye as a protoet-ing device and to doubly insulate the conducting stein or rod 13.

Suitable packing rings 20 and Q1 are arranged around the plug 6, the ring 20 being arranged between the outer face of the nut 7 and the-inner end of the shell 17 and the ring 21 between the inner face of 'the nut 7 and the shoulder 6. These

packing rings

20 and 21 provide for the expansion and contraction to which these plugs are subjected owing to the extreme changes in the te1nperature to which they are exposed. The

nuts

18 and 19 are also designed to seri/'e as binding nuts by Which the electric conductors from the magneto7 vibrating coil box or other suitable source of high frequency electric current, While the return current is made through the shell and engine cylinderl as usual or in some other suitable inanner. The nut 7 is preferably provided in its outer edge with a plurality of notches as shown at 7 in F ft which are designed to receive a specially constructed Wrench to yprovide for the turning of the nut below l the outer edge of the shell 1.

' The ground terminal 22 is constructed from nonecorrosive Wire in the formof a split ring and is designed to be seated in the groove l formed in the inner face near the inner end of the shell 1, said ring being sliffhtlj.' larger i in which it Le z n e is designed to be seated cause it ,to spring incase? tightly into place and the beveled edge 5 of the shell 1 facilitates the insertion of said electrode. i

The disk let is provided with a peripheral groove Q3 preferably V-shaped in cross section and forms a seat for the high tension electrode 2l which is also constructed of non-corrosive Wire in the form of a split ring which is a trifle smaller than -its seat to cause it to spring tightly into place7 the resiliency of the ring holding it securely Within the V-shaped groove 22. This disk 1i is also preferably provided with tivo or more recesses 1t in its outer face to provide for the insertion therein of an instrument to hold said disk against turning While the nuts at the other end of the rod are being tightened. This disk 141 is adjustable by means of the threaded rod 13 to which it is fixed and such adjustment p1o vides for the projection of the disk beyond the shell 1 to permit ready changing of the electrode 2iand also to vary the position of the disk relatively to the skirtl 10 and the electrode 22.

The electrodes being annular in shape and constructed from Wire of a gage that will provide the proper space between the two electrodes when placed in the plug and properly adjusted. the distance between said electrodes Will be equal at all points and permit the current tol jump across from one to another at any point on the periphery of the center electrode. As the circumference is a little greater than three times the diameter, a large sparking surface will be obtain-ed. These ring-shaj'icd electrodes are also interchangeable rendering it possible to change thorn at any time thereby extending the life of the plug and avoiding the exp-ense and trouble of being constantly provided with extra sets of plugs.

By employing curved surface electrodes of such formation as to produce an annular spart gap of uniform Width throughout7 the potential between the tufo electrodes will be approximately equal completely around the spark gap for the production of an electrical discharge across said gap con-4 sisting of a plurality of sparks distributed around the gap. A condenser eiliect is produced by forming the opposing surfaces of the electrodes curved or rounded and smooth, that is, Without angular or sharp edges, points, projections or roughness. lWhen the opposing electrode surfaces are thus smooth and curved the sparks can jump in either direction across the spark gap, and the electrical energy is stored or held back to attain the high potential necessary to produce 'an exceedingly rich electrical discharge of hif'li caloric value and efficiency for'ignition j l poses. I find that peculiarly advantageous results and increased eiliciency are atta-ined in the operation of internal combustion engines by the employment. of spark plugs or ignition devices embodying electrical condensers composed of the opposing electrodes and the intervening igniting spark gaps. IVith suoli a condenser, a spark gap of the desired Width can be attained and even with an excess of oil and carbon on the condenser electrodes the exceedingly rich sparks are given oil' and the intensity thereof seems to be increased by the presence and combustion ofthe oil and carbon.

To form the electrical condensernthe opposing surfaces ot the electrodes are rounded or curved and all .tine points or roughness which might permit current leakage and thus prevent the condenser action on said surfaces, are removed. In the example shown, the two chambers formed in the shell around and Within the depending skirt 21 have annular outlets between the lower edge of the skirt. and the opposing electrodes, and the out rush of fluid from these chambers on the ignition of the charge is thus caused to sweep the lower edge of said skirt with a scavenging action as well as the electrode surfaces in passing through the annular spark gap. This outrush of fluid will tend to break and remove bridges of carbon and oil that might form across the spark gap and aid in the combustion thereof by the exceedingly rich sparks produced by the condenser. The position of the high tension electrode 2l with respect to the opposite electrode and with respect to the end of the insulating skirt l() may be varied by separating the parts and changing the position of the stop nut 15.

From the foregoing description, taken in -connection with the accompanying drawings, the construction and operation of the invention will be readily understood Without requiring a more extended explanation.

Various changes in the form, proportion and the minor details of construction may be resorted to Without depart-ing from the principle or sacrilicing any of the advantages of the invention claimed.

Having thus described my invention, what I claim is A spark plug comprising a shell having an annular groove formed at one end thereof, an electrode in the form of a split ring arranged in said groove with the inner face of said ring projecting beyond the edges 'of said groove, a longitudinally adjustablev disk mounted in said shell and of less diameter than the annular electrode secured in said shell, said disk having a peripheral groove, and an opposing electrode in the form of a split ring mounted in the groove of said disk with its periphery projecting beyond the edges of said groove and spaced from said first-mentioned elect-rode.

In testimony whereof I have hereunto set my hand in presence of two subscribing Witnesses.

GEORGE ORVILL TERRY.

Witnesses:

JnNNin ANDERSON, G'Us'r GALETMAN.