US1138372A - Spark-plug. - Google Patents

Description

J. A. GILBERT.

SPARK PLUG.

APPLICAHON man MAY 20. 1914.

Patented May 4, 19]

M2 M ATTORNEYS JOHN ALBERT GILBERT, 0F COCOA, FLORIDA.

SPARK-PL UG.

Application filed May 20, 1914.

T 0 all whom it may concern Be it known that I, JoHN A. GILBERT, a citizen of the United States, and a resident of Cocoa in the county of Brevard and State of Florida, have made certain new and useful Improvements in Spark-Plugs, of which the following is a specification.

My invention relates to improvements in spark plugs, and it consists in the combine tions, constructions, and'arrangements herein described and claimed.

An object of my invention is to provide a plug which is capable of giving a multi plicity of sparks, thereby insuring the explosion of gas in the cylinder upon which the spark plug is located. I

A further object of my invention is to provide a spark plug of the type described having a pluralityoi' spark gaps in series, these gaps being arranged in a substantially circular are around the bottom of the plug.

A further object of my invention is to provide a. spark plug having an insulating portion bearing movable terminals with for securing the insulating portion to the body portion of the plug or removing it therefrom at will.

Other objects and advantages will appear in the following specification and the novel features of the device will be particularly pointed out in the appended claim.

My invention is illustrated in the accompanying drawings forming part of this application in which- Figure 1 is a vertical section through the plug, and Fig. 2 is a iierspective iew of the bottom of the plug.

In carrying out my invention I provide an exterior metallic casing 1 having a shoulder 2 and a threaded portion 3, the latter being designed to enter the threaded opening in the end of the cylinder (not shown). The casing provided with a terminal 4, as shown in the drawings. Arranged to fit in the casing is a central insulating member 5 which is provided at its bottom with a recess 6. This central portion bears a central conductor 7, the latter passing through a head 8, which surmountsthe insulating member 5, the nut 9 being provided to fit on the other end of the conductor 7. 0n the bottom of the casing is disposed an insulating block or plate 10 which bears a series of conductors. ()ne of these conductors a has branchesa and a" which are bent laterally. The branch a is dis- Specification of Letters Patent.

Patented May 4, 1915. Serial 230. $39,750.

posed in close proximity to a conductor 6, being spaced therefrom by a distance which forms a proper spark gap. The end 6 of the conductorv o is similarly disposed with respect to a conductor 0, the end 0 of the conductor 0 being similarly disposed with respect tothe conductor 03 and the end d of the conductor d being separated from the terminal 4 in order to provide a spark gap.

The insulating bottom plug or plate 10 is provided with a central boss 11 which is arranged to enter in the recess 6 in the bottom of the central insulating member 5. A jam nut 12 holds the central insulating member 5 securely by forcing the latter in contact with the Walls of the casing, the gaskets 13 being provided as shown in the drawing.

From the foregoing description of the' various parts of the device the operation thereof may be readily understood.

In assembling the plug the conducting member 7 will pass through the bottom of the block I U and up through the central part of the member The conductor 7 is provided with a head 14 which limits the upward movement, a terminal 15 extending downer); ly beyond the head as shown in the drawngs. The terminal 4 of the easing 1 is placed in a slot 10 in the insulating plate 10 and the central insulating member is then placed over the rod and secured in position by means of the jam nut 12. It will be seen that the terminal 4 has a double function. It not only serves as a terminal but cooperates with the socket 10 in the member 10, to form a centering member so as to bring the end terminals of the sparking circuit in proper position. The nut 9 is designed to bind the terminal of the lead wire (not shown) against the head 8. When the plug is assembled as described the terminal a of the conductor a is disposed at a proper distance from the terminal 15 to produce a spark. It will be seen that there are five spark gaps, these spark gaps being in series between the terminul 15 and the terminal 4. The increased number of spark gaps insures the proper explosion of the gaseous mixture. It often happens that a plug willmiss fire from the fact that the gas immediately surrounding the spark gap is not mixed in the proper proportions while the gas in another position may be of the right proportions to very readily explode. This is especially true in engines having projecting parts on the insides of the cylinders which direct the movement of the incoming charge, thereby creating currents which may bring to the ordinary spark gap a charge too rich or too lean to properly explode. This is especially true in engines of the two-cycle type. With my invention the chances of explosion are increased because of the multiplicity of spark gaps and their distribution about the end of the plug. I have found in practice that this device insures explosion Where plugs of the ordinary type will not, thereby increasing the power of the engine.

I claim A spark plug comprising a casing, a central insulating member secured to said casing and provided with a conducting rod, an insulating plate disposed at one end of said casing and having a portion arranged to enter said central insulating member, and being provided with a slot, a plurality of conductors carried by said plate and spaced apart from one another to provide spark gaps, said conducting rod being arranged to project through said insulating plate and having a portion serving a central terminal, one of the conducting members being spaced apart from said terminal to provide a spark gap, and a terminal carried by said casing and arranged to project through the slot in said insulating plate into close proximity to another of said conductors but spaced from the latter to provide a spark gap JOHN ALBERT GILBERT.

Witnesses:

L. S. ANDREWS, R. N. ANDREWS.

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