US2648320A - Spark plug - Google Patents

Description

A 1953 H. P. PHILLIPS ET AL 4 ,54

SPARK PLUG Filed Oct. 8, 1951 A? M 32 77. 5- INVENTORS,

Patented Aug. 11, 1953 SPARK PLUG Harold P. Phillips and Rex J/L. Dutterer, Hastings, Mich., assignors to Hastings Manufacturing Company, Hastings, Mich., a corporation of Michigan Application October 8, 1951, Serial No. 250,266

2 Claims.

This invention relates to improvements in a spark plug.

The main objects of this invention are:

First, to provide a spark plug in which the electrodes are effectively protected against erosion and against accidental injury in handling but at the same time one in which the ground electrodes may be easily and effectively gapped or adjusted.

Second, to provide a spark plug having these advantages in which the ground electrodes may be easily adjusted through a considerable range to adapt the same for the requirements of particular engines.

Third, to provide a spark plug structure having these advantages which may be very economically produced.

Objects relating to details and economies of the invention will appear from the description to follow. The invention is pointed out in the claims.

A preferred embodiment of the invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a side elevational View of a spark plug embodying our invention.

Fig. 2 is an enlarged inner end view, a tool being shown in section and positioned to adjust one of the ground electrodes.

Fig. 3 is a fragmentary view partially in longitudinal section on a line corresponding to line 3-3 of Fig. 2.

Fig. 4 is an enlarged fragmentary View in section on a line corresponding to line 4-4 of Fig. 2.

It should be understood that all of these views are considerably enlarged and that no effort has been made to show parts in their exact proportions. This is done for clearness and convenience in illustration.

In the accompanying drawing I represents the insulator portion of a spark plug and 2 the insulator shell. The mounting of the insulator within the shell is not illustrated as that forms no part of our present invention. The insulated electrode 3 is suitably mounted and sealed within the insulator and is supported with its inner end projecting centrally of the shell. The shell is externally threaded at 4 to be screwed into a suitable bore provided therefor in the cylinder block or head. It will be noted that the insulated electrode 3 terminates within the shell, its inner end being preferably flush with the inner end of the shell.

The ground electrodes 5 are fixedly secured to the shell in current and heat transfer relation thereto. This connection is formed by forming angularly spaced slots 6 in the end of the shell and opening to the inner end edge thereof. The electrodes 5, which are desirably of fiat section, are disposed in these slots and welded thereto as indicated at l in Fig. 4. The electrodes are disposed within the shell and guarded thereby with their inner ends free.

The electrodes are desirably formed of fiat bendable stock. They are positioned in angular relation to each other. In Fig. 2 there are two electrodes 5 and they are positioned at right angles relative to each other with their inner ends adjacent but spaced sothat a tool such as a screwdriver blade 8 may be fulcrumly supported on the end of one electrode and engaged with the adjacent electrode for adjusting it relative to the insulated electrode 3.

For the most satisfactory performance the spark plug gaps'should be such as to meet the requirements of the particular engine, either as original installation or replacement spark plugs, or cleaned spark plugs. The ground electrodes of applicants spark plugs are readily adjusted at the factory to meet the requirements of a particular engine, or are adjusted by the installer.

Spark plugs having multiple ground electrodes are generally recognized as being longer lasting than single electrode plugs, inasmuch as the ground electrodes are not eroded or disintegrated as rapidly. In the applicants structure the multiple ground electrodes are so arranged that they are well protected within the shell and at the same time may be very conveniently and accurately spaced or gapped. The applicants do not wish to be understood as urging that sparks pass between the insulated electrode and all of the multiple ground electrodes at the same time, although this might occur; applicants observa tion is that the spark passes between the insulated electrode and the ground electrode which is closest thereto until that electrode is eroded to such an extent that the spark passes between another ground electrode and the insulated electrode, and this continues more or less in rotation; that is, when one ground electrode is worn or eroded so that its gap exceeds that of another, the sparking shifts. However, it is important, as stated, to provide for accurate and easy adjustment when the plugs are manufactured and also when they are installed as replacements or renewals.

We have illustrated and described our invention in three very practical embodiments thereof. We have not attempted to illustrate or describe the invention in the various adaptations of which it is capable as we believe the disclosure made will enable those skilled in the art to embody or adapt the invention as may be desired.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A spark plug including an insulator and an insulated electrode carried thereby and projecting from its inner end, a tubular metallic shell for said insulator, the insulated electrode being supported centrally of and terminating within the shell, the shell having angularly spaced slots in the wall thereof extending axially from its inner end edge, and bendable ground electrodes of flat section disposed vertically edgewise with their outer ends in the slots and weldingly bonded to the walls thereof and with their inner ends free and positioned within the shell and guarded thereby and in side overlapping relation to the insulated electrode and laterally bendably adjustable relative thereto, said ground electrodes being angularly disposed relative to each other with their free ends in spaced, nonoverlapping ofiset relation to enable a tool being introduced between their ends and fulcrumly positioned on the free end of a selected electrode and in engagement with the inner side of the free end of the adjacent electrode to facilitate the outward adjustment of the ground electrodes relative to the insulated electrode, the free ends of the ground electrodes being spaced inwardly from the shell to facilitate the inward adjustment thereof with a tool in fulcruming engagement with the interior of the shell.

2. A spark plug including an insulator and an insulated electrode carried thereby and projecting from its inner end, a tubular metallic shell for said insulator, the insulated electrode being supported centrally of and terminating within the shell, and bendable ground electrodes having their outer ends fixedly secured to the wall of the shell in angularly spaced relation with their inner ends free and positioned within the shell and guarded thereby and in side overlapping relation to the insulated electrode and laterally bendably adjustable relative thereto, said ground electrodes being angularly disposed relative to each other with their free ends in spaced, non-overlapping ofifset relation to each other to enable a tool being introduced between their ends and fulcrumly positioned on the free end of a selected electrode and in engagement with the inner side of the free end of the adjacent electrode to facilitate the outward adjustment of the ground electrodes relative to the insulated electrode.

HAROLD P. PHILLIPS. REX J. L. D-UTTERER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,623,468 Ellett Apr. 5, 1927 2,270,765 Nowosielski Jan. 20, 1942 2,294,248 Smulski Aug. 25, 1942 2,368,889 Setterblade Feb. 6, 1945

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