US1136961A - Spark-plug. - Google Patents

Description

1. P. INMAN & R. E. ESTES.

SPARK PLUG.

APPLICATION FILED NOV-1|, 1913- I I 1 ,136,961, Patented Apr. 27, 1915.

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, certain new and useful UNITED STATES PATENT OFFICE.

JOHN 1P. INMAN" AND ROBERT E. ESTES, OF MIDLAND, TEXAS.

SPARK-PLUG.

To all whom it-may concern:

Be it known that we, JOHN P. INMAN and ROBERT E.' '?E sjrns, citizens of the United States, residing atLMidIa-nd, in the county of Midland and State of Texas, have invented Improvements in Spark-Plugs, of which the following is a specification.

Our invention relates to improvements in spark plugs, such as are used in explosive engines, and one object of the invention is to provide means whereby the electrodes of the spark plug maybe readily cleaned while the motor is running, and whereby the electrodes may be adjusted into greater or less contiguity with each other, so as to thereby adjust the distance across which the spark will jump.

A further object of the invention is to so construct the base of the spark plug that by removing the porcelain insulator and the bushing supporting it, a tire pump may be connected with the plug base, thus doing away with the necessity of removing the plug entirely from the cylinder of the engine and inserting the pipe of the tire pump in engagement with the screw threads of the cylinder. The reason for this is that the engagement and disengagement of the tire.

pump pipe with the screw threads of the cylinder tends to wear the screw threads in cylinder. The spark plug base, however, may be readily removed and replaced at any time if the threads are worn in plug base.

A further object of the invention is to provide a spark plug so constructed as to permit gasolene or other liquid to be poured through the plug whereby to prime the motor or to clean the plug.

A still further object is to provide a plug of the character stated, very simply and cheaply constructed wherein all the parts are readily removable and replaceable.

Our invention is illustrated in the accompanying drawings, wherein Figure 1 is a longitudinal section of a spark plug constructed in accordance with our invention. Fig. 2 is a perspective view of the electrode pin." Fig. 3 is a perspective view of the cap supporting the electrode pin and of the lock nut thereon.

Corresponding and like parts are referred to in the following description and indicated in all the views of the accompanying drawings by the same reference characters.

Referring to these drawings, 2 designates Specification of Letters Patent. P t t d Ap 27 1915 Application filed November 11, 1913. Serial No. 800,282.

the plug base. The lower portion 3 of this base is cylindrical in form and exteriorly screw-threaded, as at 4. The upper portion 5 of the base is also cylindrical in form but has an internal diameter equal to the external diameter of the portion 3. The upper portion of thebase is internally screwthreaded as at 6. Engaging the upper portion of the base is a clamp bushing 7 which is exteriorly screw threaded and formed with a head whereby it may be rotated. Fitting within the base 2 is the porcelain insulator 8 which is formed intermediate its ends with an-a'nnular flange or shoulder 9. The diameter of the flange or shoulder is equal to the interior diameter of the base. The insulator below the shoulder 9 has an interior diameter equal to the interior diameter of the portion 3 of the base while the upper portion of the insulator above the shoulder 9 is sufl'iciently smaller in diameter than the upper portion of the base 5 to permit the insertion of the bushing 7.

Mounted upon the upper end of the insulator is the cap or head 10. This cap is cylindrical in form and is provided intermediate its ends with the annular flange 11 which fits upon the upper end of the insulator. The lower end of the cap fits into the annular recess formedin the upper end of the insulator. The cap is interiorly screw-threaded as at 12, these screw-threads extending the full length of the cap. Disposed within the insulator is the metallic sleeve 13, the upper end of which is screw threaded for engagement with the lower end of the cap 10 and the lower end of the sleeve is enlarged as at 14, the lower end of the hollow interior of the insulator being enlarged as at 15 to accommodate this enlargement of the cap. A gasket 16 of copper or asbestos is disposed between the flange 9 of Iighe insulator and the shoulder .17 of the ase.

Passing through the center of the sleeve 13 is the electrode pin 18 which is enlarged at its upper end as at 19, this enlargement being screw-threaded to engage the screw threads 12 on the cap 10. The electrode pin 18 fits the sleeve 13 snugly and projects below the lower end of the sleeve and its lower extremity is disposed in contiguity with the.

electrode bar 20. This electrode bar and theelectrode pin are preferably made of nickel. The upper end of the electrode pin is formed with a head 21 having means whereby the electrode pin may be rotated, this means preferably being a notch or nick 22 extending transversely across the upper face of the head. A lock-nut 23 engages the screw threaded portion 19 and bears against the upper end of the cap 10. This lock-nut is preferably formed with laterally extending wings or prolongatlons so that it may be readily manipulated without the necessity of using a wrench. These wings permit the nut to be turnedby means of a stick or any like member of insulating material. The wires energizing the electrode 18 are secured to the cap 10 by means of a clamp nut 25 which engages the screw threads 26 formed upon the exterior of the upper end of the cap 10. hen the clamp nut 25 is turned down it binds the conducting wires between the clamp nut and the flange 11.

The particular object of forming the upper portion 5 of the base 2 with an interlor diameter equal to the exterlor d1ameter of the lower portion 3 is to permit the pipe leading to a tire pump to be inserted in the plug base instead of havmg to remove the plug entirely from the cylinder. This obv1- ates the wear on the threads of the cylinder and it will be obvious, also removes the necessity of entirely removing the spark plug in order to connect saidtire pump with the cylinder. 4

Vhile we do not wish to limit ourselves to the number of threads on the'portion 19 of the electrode pin, preferably this pm has thirty-two threads to the inch, so that one full turn of the electrode pin in one d1rection will give a gap between the lower end of the pin and the bar 20 one thirty-second of an inch wide. To set spark gap at one sixty-fourth of an inch, the electrode pin 18 is turned half around. It will be understood that this ratio between the amount of rotative movement of the pin and the gap between the lower end of the pin and the bar 20 may be changed to any extent desired. By adjusting the pin 18 in the cap 10 the gap between the bar 20 and the lower end of the pin may be accurately adjusted to any extent desired, and it is obvious also that the amount of this adjustment may be accurately determined by the number of rotations given to the head 21. Furthermore it will be obvious that by rotating the pin so as to shift it downward andbring its lower end into engagement with the projection 20 on the electrode bar 20 the plug can be cleaned while the motor is running. After the spark points are cleaned it is an easy matter to return the original position.

It will be seenthat the electrode pin 18 may be entirely removed from the plug and that when so removed, gasoleneor other liquid may be poured through the plug into electrode to its the cylinder, thereby to clean or prime the motor or to clean the plug.

Gaskets 27 and 28 are disposed, the first under the nut at the upper end of the sleeve 13 and the other between the enlarged lower end of the sleeve and the shoulder on the insulator. These gaskets make a gas-tight joint at all times andcompensate for the expansion and contraction of the sleeve. The gaskets are made of material having a greater coefficient of expansion and contraction than the sleeve, and it will therefore be obvious that the expansion and contraction of the sleeve and the gaskets are opposed.

\Vhile we do not wish to limit ourselves to the material from which the plug is made, we find in practice that it is best to make the base, bushing and cap, of iron or steel; the insulator of porcelain, and the electrode pin or bar of nickel.

It is likewise to be noted that the insulating core 8 is easily removable from the base by simply removing the bushing 7, thus permitting the ready introduction of a new insulator at any time.

It is to be noted that not only is the upper portion of the plug base of the same diameter as the internal diameter of the lower portion of the plug base, but the screw threads have the same pitch.

Having thus described the invention what is claimed as new is 1. In a spark plug, an insulator having a bore extending longitudinally therethrough, a sleeve fitting the bore, the upper end of the sleeve extending beyond the upper end of the insulator, an electrode passlng through the sleeve, and a cap resting upon the upper end of the insulator and engaging with the upper end of thevsleeve, having independent screw threaded engagement with the upper end of the electrode.

2. In a spark plug, an insulator having a bore extending longitudinally therethrough,

a sleeve screw-threaded at its upper end and enlarged at its lower end p'assingthrough said bore, a cap disposed upon the upper end of the insulator and interiorly screw threaded to engage said sleeve, an electrode pin passing through the sleeve and insulator and having .screw threaded engagement at its upper end with said cap.

3. In a spark plug, an insulator having a bore extending longitudinally therethrough, a sleeve screw-threaded at its upper end and enlarged at its lower end passing through said bore, a capdisposed upon the upper end of the insulator and interiorly screwthreaded to-engage said sleeve, an electrode pin passing through the sleeve and insulator and having screw-threaded engagement at its upper end with said cap, whereby the electrode pin may be longitudinally adjusted with relation to the cap and sleeve, and

means for locking the electrode pin in any adjusted position.

4. In a spark plug, an insulator having a longitudinally extending bore, a sleeve fitting said bore and having an enlarged lower end, the upper end of the sleeve being exteriorly screw-threaded, a cap on the upper end of the insulator having screw-threaded engagement with the sleeve and extending beyond the sleeve, an electrode pin passing through the sleeve and said cap, and having screw-threaded engagement with the cap, and means for locking the electrode pin in any desired position.

5. In a spark plug, a tubular insulator, a tubular sleeve disposed therein, a tubular cap on the insulator, and an electrode pin passing through the sleeve and insulator and having screw-threaded engagement at its upper end with said cap said sleeve having screw threaded engagement with the cap.

6. In a spark plug, a tubular insulator, a tubular member passing through the insulator and engagedtherewith against upward movement, an electrodepin screw-threaded at its upper end, and a member mounted upon the insulator through which the electrode pin passes and with which the screw threads of the electrode pin have engagement, said member having screw threaded engagement with the first-named member whereby to permit the electrode pin to be entirely removed from the insulator to thereby permit the introduction of liquids into the *7 cylinder through the insulator.

7. In a spark plug, a tubular insulator having a central bore, the upper end of the insulator being recessed immediately surrounding the bore, a cap mounted on the upper end of the insulator and having interior screw threads, said cap extending down into the said recess, a sleeve disposed withinthe insulator bore having an enlarged lower end, the upper end of the sleeve having screw-threaded engagement with the lower end of the cap, and an electrode pin having a smooth surface passing through the sleeve, the upper end of the electrode pin having screw-threaded engagement with said cap.

8. In a spark plug, a tubular insulator having a central bore, the upper end of the insulator being recessed immediately surrounding the bore, a cap mounted on the upper end of the insulator, said cap extending down into the said recess, a sleeve disposed within the insulator bore having an enlarged lower end, the upper end of the sleeve having screw-threaded engagement with the lower end of the cap, an electrodepin having a smooth surface passing through the sleeve, the upper end of the electrode pin having screw-threaded engagement with said cap, and a lock-nut engaging the screw threaded portion of the pin and bearing against the upper end of the sleeve.

9. In a spark plug, a plug base enlarged at its upper end, the exterior of the lower end being threaded to engage a compression chamber, the interior of the upper end being threaded, a tubular insulator, the lower end of which fits the lower end of the plug base, a clamp bushing engaging the insulator and the upper end of the plug base, a sleeve disposed within the insulator, a tubular cap upon the insulator interiorly screw threaded for its entire length, the upper portion of said cap being exteriorly screw threaded, an electrode pin having a smooth surface for the greater portion of its length and passing through the sleeve, the upper portion of the pin being enlarged and screw-threaded to engage the screw threads of the upper portion of the cap, a head on said electrode pin whereby it may be rotated, a lock-nut engaging the screw threads of the electrode and bearing against the upper end of the cap, and a wire clamp nut engaging said cap.

, 10. In a spark plug, an insulator having a central bore enlarged at its upper end, a tubular element disposed in the enlarged upper portion of the bore of the insulator, the interior diameter of said tubular element being the same as the interior diameter of the contracted portion of said central bore, said tubular element being interiorly screwthreaded, and an electrode passing through the bore of the insulator and having screw threads at its upper end engaging with said tubular member, whereby to permit the removalof the electrode and permit the introduction of liquid into the cylinder through the plug.

11. In a spark plug, an insulator having .a longitudinally extending bore, a sleeve fitting said bore and having an enlarged lower end, a cap on the upper end of the insulator having screw-threaded engagement with the sleeve, an electrode pin passing through the sleeve and the cap, and gaskets disposed be; tween the cap and the insulator and between the enlarged end of the sleeve and the insulator, said gaskets having a greater coefficient of expansion and contraction than the sleeve and cap.

In testimony whereof we aifix our signatures in presence of two witnesses.

JOI-Ih P. INMAN. [L. s.] ROBERT E. ESTES. [Ls] Witnesses: A. B. Es'rns,

D. W. BRUNSON.

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