US1927267A - Spark plug - Google Patents

Description

L. K. JAMES Sept. 19, 1933.

SPARK. PLUG Filed Aug. 24, 1931 Patented Sept. 19, 1933 UNITED STATES PA'naN'r OFFICE."

3 Claims.

This invention relates to a spark plug. I An object of the invention is to provide a spark plug of the character described having novel means for connecting the electrical conductor thereto.

Another object of the invention is to provide in a spark plug, a novel type of connection serving the double purpose of connecting the electrical conductor to the electrode of the plug and of inclosing and protecting theouter end of the plug against moisture and other foreign matter.

With the above and other objects in view this invention has particular relation to certain novel features of construction, arrangement of parts and'use, an example of which is given in this specification and illustrated in the accompanying drawing wherein:

Figure 1 shows a side elevation of the plug partly in section,,and

Figure 2 shows a cross sectional view taken on the line 2-2 of Figure 1.

Referring now more particularly to the drawing wherein like numerals of reference designate similar parts in each of the figures, the numeral 1 designates the tubular jacket of the plug, composed of suitable metal and preferably made in two sections. The inner end of this jacket is reduced and threaded as at 2 for connection in to the motor cylinder in the usual way. Within the jackets 1 there is the procelain 3 whose inner end is tapered or contracted as. at 4 and thus spaced from the inner end of the pocket.

This porcelain has the external annular shoulders ,5, 6 which are clamped between the opposing parts of the sections of the jacket 1 as shown in Figure 1. Extending axially through'the porcelain there is an electrode 7, whose inner end is spaced from the terminal 8 which is grounded on the jacket 1.

The outer end of the porcelain 3 has a deep socket 9 into which the outer end of the electrode extends, said extended end being threaded and screwed onto said threaded end there is a nut 11 which carries the outwardly extended flexible prongs 12, 12.

There is a cap 13 formed of suitable material such as bakelite, which has the inward tubular extension 14 which fits closely withinthe socket 9. This extension 14 has a deep axial bore 15 in which there is located a metallic plug 16, preferably brass, and a sleeve 17 is preferably formed integrally with said plug and lines the inner end of saidbore 15. The prongs 12 fit closely within the sleeve 1'! when the, parts are assembled.

The cap 18 has a lateral extension 18 sleeve (Cl. 123-169) I t like in form and having the bore 19 to receive the conductor 20. The bore 19 is reduced and extended on through the plug 16 to receive the wire 21, of said conductor and a screw 22 is threaded outwardly through the plug 16 and its outer end 0 clamps the wire 21 securely in place. This screw has an enlarged head 23 which fits closely within the sleeve 1'7.

The outer end of the jacket 1 is reduced as at 24 and the cap 13 fits over said reduced portion 5 .forniing a flush joint with the jacket 1.

The outer end cap 13 may be readily pulled oif of the jacket when it is desired to disconnect the plug from the. distributor and may be as readily, replaced on the jacket, the prongs 12 fit- 7o ting closely within the sleeve 17-and forming an electrical connection between said sleeve and the electrode 7 and the screw 22 forming an electrical connection between said sleeve and the conducting wire 21. The cap 13 will serve not only to form a strong connection for the terminal wire 21 but will also protect the same against moisture and will also inclose and protect the outer end of the spark plug proper and will keep the same dry. 4

The drawing and description disclose what is now considered to be a preferred form of the invention by way of illustration only, while the broad principle of the invention will be defined by the appended claims.

.What 1 claim is:

1. In a spark plug having a jacket, an insu lator secured therein provided with an outer end socket, an axial electrode through the insulator, contact prongs on said electrode in said socket; a detachable cap fitted over the outer end of said jacket and having an extension which fits into said socket, a tubular contact sleeve in said extension into which said prongs fit, said cap having a lateral extension provided with a bore for the reception of. an electrical conductor, a plugin said cap at the outer end of said sleeve through which said bore extends, a screw in said sleeve threaded through said plug and whose outer end v is adapted to engage and secure said conductor 100 in place. 1

.2. In a spark plug having an outer jacket, an insulator secured in the jacket and having an outer end socket and an axial electrode through said insulator; a detachable cap. associated with 105 the outer end of the insulator and provided with a bore for the reception of an electrical conductor, means in the cap for clamping said conductor in place, said insulator and cap being provided, one with a sleeve and the" other with 110 prongs which fit in the sleeve to provide an electricalconnection between said conductor and electrode. r

3. ,A' terminal connector for a spark plug, said I plug having a deep end socket withgan electrode flexible prongs in said socket, said connector comprising a detachable cap provided with aitubular extension fitted closely into said socket said-extensicnbeing provided with an axial bore, a metallic plug in said bore and a metallic sleeve (lining the inner end of said bore and electrically

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