US1512564A - Spark plug - Google Patents

Description

' 1,512,564 J. B. ROGERS SPARK PLUG fOct. 21 1924.

Filed July 25. 1921 l 4&4 A s ZWM w Patented ct. 2l, 1.924.

UNITED STATES nuns n. means, or cmcneo, ILLINOIS.

SPARK PLUG.

Application filed July 25, 1921.

-means are provided for preventing twisting the central conductor within the insulating core or body.

A further object of my invention is to provide an improved spark plug provided with a metallicv sheath surrounding the insulating core, and with a swivel ring bearing on this sheath to secure the plug in place.

A further object of my invention is to provide improved packing means at the end of the central conductor which extends through the insulating core.

A further object of my invention is to provide an improved spark plug having a metallic sheath surrounding the insulating core, with this metallic sheath carrying one of the electrodes.

A urther object of my invention is to provide an improved spark plug which will be durable and eicient in operation, simple in construction and cheap to manufacture. Further objects will appear from the detailed description to follow and from the ap ended claims.

the drawings in which two embodiments of my invention are shown- Figure 1 is a central axial section through a spark plug;

F ig. 2 is a section on the line 2-2 of Fig. l

Fig. 3 is a section on the line 3-3 of Fig. 2

Fig. 4 is a detail perspective view of a split ring; V

Fig. 5 is a detail view showing the mounting of one of the electrodes, and

Fig. 6 is a view showing a modification.

Referring rst to F 1 to 5 inclusive, the spark plug shown therein comprises an insulating ase or core 10, an electrode 11 mounted at the inner end of the core 10, a wiring terminal construction 12, mounted at the outer end ofthe core 10, a conductor f 13, electrically connecting the electrode 11 and the wiring terminal 12, `a metal sheath Serial No. 487,327.

14 surroundingthe enlarged central portion of the core 10, an electrode 15 carried by the sheath 14, a threaded ring or sleeve 16- which may be screwed into the cylinder head to bring the electrodes 11 and 15 into the desired position. Suitable packing washers 19 and 20'may be provided between the sheath 14 and the insulating core 10 to prevent the escape of gas and to provide a cushion betweenthe metal and porcelain. A suitable packing washer 21 may be provided between the sheath 14 and the bushing 18. These packing washers may be of any suitable material, and may be of the type known as copper asbestos washers. Also, a suitable packing washer 22 may be provided at the inner end lof the core 10, between the shoulder portion 23 0f the central conductor 13, and the shoulder portion' 24 on the pnrcelain core to prevent the escape of gas att 's point and to provide a cushion between the metal and porcelain.

Inorder to relieve the central conductor 13 from any twisting strain, due to the screwing down or up of the binding screw 25, means 26 arei provided at the upper end of the insulating core 10, to hold the central conductor 13 against rotation inside of the core 10. This means comprises a washer member 27 having a central key-hole shaped opening 28, through which the central conductor 13 eXtends,-the central conductor 13 having a fiattened portion 29 at the point where it extends through the washer, which flattened portion lies in the elongated portion of the key-hole slot, so that relative rotation between the conductor and washer is prevented. Relative rotation between the washer and porcelain core 10 is prevented by means of downwardly extending projections 30 on the washer which fit into notches 31 (Fig. 3) in the porcelain core. Thus relative rotation is prevented between, the central conductor 13 and the porcelain core 10. A sealing compound of cement may be pro- .vided at the upper end of the insulating core 10, as indicated at 32, to further effectually seal the connection between the central conductor 13 and the porcelain core 10 at this point.

In assembling the central conductor 13 with respect to the porcelain core 10, the central conductor carrying the electrode 11 tion 29 of the central conductor into the narrow portion of the key-hole slot to prevent relative rotation between the washer and conductor, rlhe washer 27 is then titted to the core 10 so that the lugs 30 will enter the notches 31, and the holding nut 34 is then screwed down to draw the central conductor 13 firmly into place. As the nut 34 is screwed down, the shoulder 23 of the central conductor is caused to be drawn snugly against the packing washer 224 at the inner end oi the' core to elect a tight connection at this point. Drawing down the nut 34 also forces the washer 27 tirmly into place, and also compacts the cement at 32 (which has not yet hardened). The electrodes 11 and 15 may be of iridium, tungsten or other metals having a high melting point, spot-welded to their supporting members. For this purpose, the electrode 11 is provided with a shank` portion 35, which extends into a recess or socket in the end of the conductor 13. After the electrode is in place, it may be spot-welded or otherwise suitably secured. The electrode 15 is provided with an enlarged portion 36 at its upper end (Figh) which lies in a suitable notch or recess 37 ,in the skirt portion of the sheath 14. After the electrode 15 has been placed in position with respect to the sheath 14, it may be secured in pla-ce by pressure and spot-welding, or in any suitable manner.

The swivel ring 16 may be held in place on the sheath 14 by means of a split ring` 37, which can be sprung into place into an annular channel in the sheath. This split ring 37 keeps the swivel sleeve 16 in place on the sheath 14e If desired, an anti-friction ring 38 may be' pro/vided between the shoulder 39 of the sheath 14 and the lower edge` of the swivel' sleeve 16.

It will be noted that both of the electrodes are mounted on the central core 10 so that the adjustment is not disturbed when the central core 1G is removed from the bushing 17 for cleaning, etc. so that no readjustment of the electrodes is necessary in reassembly.

It will also be noted that the constructionshown is in effect a complete spark plug without the bushing 17, as the bushing 16 may be, if desired, screwed directly into the.

head of the cylinder as shown in Fig. 6. In Fig. 6 the construction may be substantially the same as that shown in Fig. 1, except that the bushing 17 is omitted, and the swivel asiatica sleeve 16 is screwed directly into the cylinder head 40, ln this construction, the cylinder head is provided with a shoulder portion 41 against which the packing ring 2]. bears, and is provided with an internally threaded portion 42, into which the swivel ring 16 screws.

It willl be seen that in both constructions is provided a plug which can be connected and disconnected simply by screwing in or out the swivel ring 1b, and in which it is not necessary to take the plug apart for cleaning, and in which there is no danger of any twisting strain being exerted on that portion of the central conductor 18 which lies inside the' porcelain core, und in which provision is made for preventing the escape of gas, and for cushioning the engagement between the metal parts and. the porcelain.

Having thus described my invention, what l claim as new and desire to secure by Letters Patent of the United States is z- 1. A. spark plug construction comprising an insulating body, an electrode at one end thereof, a wiring terminal at the other cud thereof, a conductor extending axially through said insulating body, and electrically connecting said electrode and wiring terminal, said insulatin body having an enlarged portion, a meta sheath embracing and surrounding said enlarged portion said metal sheath having two annular shoulders, one facing outwardly7 and the other facin inwardly, a sleeve surrounding and swivelcd on said sheath and bearing on said outwardly facing shoulder, a member having an outwardly facing annular seat, an annular gasket on said seat, said member and sleeve being provided with intercngaging means whereby swiveling movement of said sleeve about said sheath will force the sleeve inwardly, to force the inwardly facing shoulder on the sheath into sealing engage ment with said gasket; and to force the gasket into sealing engagement with the seat on said member. l

2. A spark plug construction comprisin an insulating body, an electrode at one en thereof, a wiring terminal at the other end thereof, a conductor extending axially through said insulating bod and electrically connecting said electr e and wiring terminal, said insulating body having an enlarged portion, a metal sheath embracing and surrounding said enlarged portion, said metal sheath having two annular shoulders, one facing Ioutwardly and one facing inwardly, a sleeve surrounding and swiveled on said sheath and bearing on said outwardly facing shoulder, means on said sheath for holding said threaded sleeve against movement away from said shoulder, a member having an annular outwardly facing seating shoulder, an annular gasket on said shoulder, said member and sleeve being provided with interenga. -ng means whereby swiveling movement o said sleeve about said sheath will force the sleeve inwardly, to force the inwardly facing shoulder onthe sheath into sealing en agement with said gasket and to force sai gasket into sealing enga ement with the outwardly facing shou der on said member.

3. A spark Ellg construction comprising an insulating an electrode at one end thereof, a, wiring terminal at the other end thereof, a conductor extending axially through said insulating body, and electrically connecting said electrode and wiring terminal, said insulating body having an enlarged portion, a metal sheath embracing and surrounding said enlarged portion, said metal sheath having twoannular shoulders,

one facing outwardlyyfand the other facing inwardl an electrofde carried by said sheath or cooperation with said first electrode, a sleeve surrounding and swiveled on. said sheath and bearing on said outwardly7` facing shoulder, a member havin an outwardly facing annular seat, an annu ar gasket on said seat, Lsaid member and sleeve being provided with interengaging means whereby Swiveling movement of said sleeve about said sheath will force the sleeve inwardly, to force the inwardly facing shoulder on the sheath into sealing lengagement with said gasket, and to force the gasket into sealing en agement with the seat on said member.

Witness whereof, I have hereunto subscribed my name.

JAMES B. ROGERS.

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