US1968225A - Spark plug - Google Patents

Description

July 3l, 1934. G. SHELL Er AL SPARK PLUG Filed NOV. 16. 1932 Squeak-WH ATTORNEY.

latented July al., luar SPARK PLUG Gustave A. sneu, Garden city, and Bernard Zettel-land, Detroit, Mich.

` Application November 16, 1932, Serial No. 642,910

2 Claims.

Our invention relates to new and useful improvement in a spark plug and has for its object the provision of a spark plug which may be economically manufactured, which may be easily and quickly assembled at a minimum cost and which will be durable and efficient in use.

Another object of the invention is the provision of a spark plug possessed of a maximum eniciency and formed from a minimum number of parts.

Another object of the invention is the provision of a spark plug having an insulating core provided with a coiled electrode threaded therein and projecting outwardly therefrom its opposite ends thereof.

Gther objects will appear hereinafter.

The invention consists in the combination and arrangement of parts hereinafter described and claimed.

The invention will be best understood by a reference to the accompanying drawing which forms a part of this speciiication, and in which,

Fig. 1 is a longitudinal central sectional view of the invention.

Fig. 2 is a sectional view taken on line 2-2 of Figure 1.

Fig. 3 is a sectional view taken on line 3 3 of F18. 1.

Fig. 4 is a longitudinal central sectional view of a slightly modified form of the invention.

The invention comprises a metallic sleeve or shell 'Z having the enlarged flat faced portion 8 and provided at ,one end with the peripherally threaded portion 9. The outer or upper end of the spark plug is recessed as at 10, and internally threaded. 'I'helower end is slightly enlarged to provide the restricted centrally positioned opening 11 and afford a shoulder 12. Resting against the shoulder 12 is the insulating core 13 which is formed cup-shaped so` as to provide the electrode receiving space or socket 14 which is internally threaded.

Threaded into this socket `14, is a. coiled electrode 16, the upper end 17 of which is angularly turned and projected through the closing cap 18 of insulating material. A nut 19 is threaded into the recess so as to press the cap 18 against l the upper or open end of the core 13 and forces the core 13 tightly against the shoulder or seat 12. This nut 19 is provided with a central opening 20 into which the' curved side of the semispherical cap 18 'may project. The angularly turned portion 17 of the electrode terminates inv a head 21 positioned within the insulating abutment block22. The head 21 is connected to the (Cl. 12S- 169) terminal screw or stem 23 on which is threaded the nut 24. The lower end of the coiled electrode is angularly turned to provide the portion 25 which cooperates with the sparking ,point 26 extending inwardly'from the lower end of the w shell 7.

1t is obvious that a maximum length of electrode is provided by the coil arrangement and, from the description given, the economy of manufacture and simplicity of assembly is believed evident.

1n the form shown in Fig. 4, We have provided a metal shell 27 having the hat faced portion 23 and the threaded portion 29. This sleeve or shell 27 has a bore 30 extended therethrough and .m

enlarged-at its lower end to provide the enlarged bore or recess 31 and affording an abutment shoulder 32. A peripheral flange 33 on the insu' lating core 15 engages against the shoulder 32 and a neck 34 projects outwardly from the ange 33. This core 15 is provided with the internally threaded socket 35 inwhich is threaded the coiled electrode 36, one end 37 of which is angularly turned and threaded and projected through the insulating washer 38. on the portion 37 as is also a binding nut 40. The vlower end of the coil is angularly turned as at 41 and projected outwardly from the core to cooperate with the sparking point 42 projecting inwardly from the shell 27. The locking nut 39 prevents the core 15 from falling out of the shell and the engagement of the iiange 33 with the shoulder 32 resists outward movement of the core when an explosion takes place inthe engine with which used.

A lock nut 39 is threaded 80 A cup shape cover 43 is pressed into the recess w 44 of the shell 27 to assist in retaining the washer 38 in position. The`nut 39 is preferably made from insulating material and when not made from insulating material is spaced from thecap 43 by a suitable washer.

In this form of construction the eiciency obtained in the form shown in Fig. 1 is present and the economy of manufacture and simplicity of assembly is also maintained.

The coiling of the electrode results in increased eillciency in that the spark is intensied. This permits ample sparking of theplug when a weak battery is used, sorthat easy starting of the engine .with which used is possible at all times.

While we have illustrated and described the preferred form of construction of our invention, we do not wish to limit ourselves. to the precise details of structure.k shown, but desire toavail ourselves of such variations and modifications as 110 EID may come within the scope of the appended claims. l l

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

1. A spark plug of the class described comprising: a metallic shell having a bore formed therethrough, said shell having intermediate the ends of said bore an engagement shoulder forming portion; an insulating core in engagement with said shoulder; means for retaining said core in engagement with said shoulder; an electrode projectedthrough said core, the portion of said electrode within said core being coiled, said core being threaded for the reception of the coil portion of said electrode. 2. In a spark plug of the class described, a. metallic shell having a bore formed therethrough; an insulating core mounted in said bore; means for retaining said core in said bore; and an electrode projected through said core, the portion of said electrode within said core being coiled, said core being threaded for the reception of the coiled portion of said electrode.

GUSTAVE A. SHELL. BERNARD ZE'I'IERLUND.

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