US2272558A

US2272558A - Spark plug

Info

Publication number: US2272558A
Application number: US341193A
Authority: US
Inventors: Earl M Hall
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-06-18
Filing date: 1940-06-18
Publication date: 1942-02-10
Anticipated expiration: 1959-02-10

Description

Feb. 10, 1942. HALL 2,272,558

SPARK; PLUG Filed June 18, 1940 Patented Feb. 10, 1942 UNITED STATES PATENT QFFECE SPARK PLUG Earl M. Hall, Salem, reg., assignor of one-half to Henry Carl, Salem, Oreg.

Application June 18, 1940, Serial No. 341,193

2 Claims.

This invention relates to improvements in spark plugs and the primary object of the invention is to design a plug that will not foul or become short circuited.

Another object of the invention is the provision within the plug for air cooling the same by air circulation.

These and other incidental objects will be apparent in the drawing, specification and claims to follow.

Referring to the drawing:

Figure l is a side elevation of my new and im proved spark plug.

Figure 2 is a sectional View of the plug, parts broken away for convenience of illustration.

Figure 3 is a plan sectional view, taken on line 33 of Figure 2.

Figure 4 is another preferred form of embodiment of my new and improved spark plug.

Figure 5 is a plan view of Figure 4.

In the drawing:

I is the main body portion of the spark plug, having the usual threaded extensions 2 for entering the motor block. The usual central electrode 3 is encased within the porcelain or insulating material 4 of usual construction. The lower end 2 of the plug is cored out at 5, slightly larger than the lower end 6 of the insulator 4. The lower end of the core 5 is partially closed by the bottom I of the lower part of the plug 2. A cup-like insulator gasket 8 rests on the bottom I and receives the lower portion of the insulator 6, best shown in Figure 2. The end I has an opening 9 larger than the lower end III of the electrode 3. This is where the spark gap is provided.

It will be noted that the opening 9 is very shallow, leaving no place for dirt to lodge. The power of the explosion will clean this spark gap chamber from any foreign matter. It will be noted that the end 1 of the lower part 2 of the spark plug is rounded in the shape of a semicircle. The reason for this construction is to provide self-cleaning of the end of the plug by the power of explosion within the cylinder head. This is a very important feature of my new and improved spark plug.

In the construction of the lower part of the porcelain 6, the gasket 8 seals all of the space between the porcelain and the lower body of the plug 2 so that there is no space for dirt or carbon to generate. This is another high-light of the invention, which is very important. The only space provided is the space 9 where the spark takes place and this space is so shallow that no dirt can lodge without being forced out by combustion.

Another feature is the provision of ventilators I I within the body of the plug I for allowing air to reach the insulator 4, spaced around its lower end 6 for cooling the same. There are a number of ventilator openings II provided for this purpose, terminating in the hollow chamber I2 which is connected to the space 5 surrounding the lower terminal 6 of the insulator 4. The insulator 4 is held in place by the usual lock nut I3 and gasket I l.

The cup-like gasket 8 may be made of insulating material in which case the bottom part of the gasket could extend over to th electrode III or the gaskets may be made of metallic material and extend to the edge of the openings 9, as shown in Figure 2. This material should expand to correspond with the rest of the plug so that a tight fit may be maintained.

Referring to Figures 4 and 5, I illustrate another preferred form of insulator terminal mounting, where the lower end I6 of the insulating terminal is made relative short resting within the insulating material IT. The shoulder I8 of the insulator is forced downward by the gasket I9 underneath the locking nut 20, which is threaded into the main body of the spark plug I5. In this construction the distance between the locking gasket I9 and the lower end of the insulator terminal I6 is shortened; this is desirable when it comes to expansion by heat. The lower end of the locking nut 20 ha openings or notches 2IA leadin to the vertical grooves 2I. This permits the circulation of air from openings 22 within the main body of the plug I5 where air is allowed to pass from the atmosphere through the openings 22 and openings 2IA and up through the groove or flute 2I around the main insulator terminal, cooling the whole assembly.

I do not wish to be limited to the particular mechanical construction illustrated and claimed, as other forms of mechanical embodiment may be employed, still coming within the scope of the claims to follow.

What is claimed as new is:

1. A spark plug including a metallic body formed with a threaded extension to secure the plug in place, the lower end of the extension being formed with an annular opening forming an electrode, the lower end of the body being upwardly curved from the edge of the opening, an insulating body having a part seated within the extension and spaced from an interior bore thereof, the body being circumferentially enlarged above the parts fitted within the extension, a strip arranged between the extension of the insulating body and the wall of the bore the lower edge of the strip terminating in line with the edge of the opening and the upper edge of the strip terminating within the extension below the enlargement of the insulating body, said strip underlying and forming a support for the insulating body, an electrode extending longitudinal- 1y of the insulating body and terminating within and spaced from the wall of the opening in the lower end of the threaded extension of the me- 10 sulating within the bore of the threaded extension is of insulating material.

EARL M. HALL.