US1347367A - Sparking plug for internal-combustion engines and method of manufacturing the same - Google Patents

Description

C. E. GERBAUI'J. SPARKINGPLUG FOR INTERNAL COMBUSTION ENGINES AND METHOD OF MANUFACTURING THE SAME.

APPLICATION FILED FEB. 24, I9l9.

Patented July 20, 1920.

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w \6 LIE M WW 7 m? y B w W C A C. E. GERBAUD. SPARKING PLUG FOR INTERNAL COMBUS APPLICATION FILED FEB. 24, I919. 1,347, 367, Patented July 20, 1920.

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Kin? f TION ENGINES AND METHOD OF MANUFACTURING THE SAME.

- UNITED STATES PATENT OFFICE.

CHARLES EMILE GERBAUD, OF PARIS, FRANCE;

SPARRING PLUG m INTERNAL-COMBUSTIONENGINES AND mnrnon or mum- FACTURING THE sun.

Specification of Letters Patent.

Patented July 20,1920.

Application filed February 24, 1919. Serial No. 278,694.

leakage of gas or lubricating oil.

A further object of this invention is to provide a plug capable of withstanding very great temperature and very heavy pressure, while always remaining completely insulated.

The characteristic features of my 1mproved plug (which is made in the manner hereinafter described) are:

1. The insulating body cast on to the central rod forming the axial electrode, and

2. The metallic shell formed of a mass of metal cast on to said insulating body.

Figure 1 of the accompanying drawing shows, in central vertical section and by way of example, one form of the single-piece plug. I

Figs. 2 and 8 illustrate the mold in which the insulating body is cast, Fig. 2 being an elevation of the inner face of one half of the mold, the insulating body being shown in section, while Fig. 3 is a plan of the mold.

' Figs. 4 and 5 represent the mold in which the metallic shell is cast, Fig. 4 showing the inner face of one half of the mold, the metallic shell being shown in section, while Fig. 5 is a plan of the mold.

As is shown in Fig. 1, my improved plug comprises an axial rod a of the usual form, constituting one of the electrodes, an insulating body I) cast on said rod, and a metallic shell or body a cast on the insulating body.

The insulating body I) may be made of sodium boro-silicate of the following comample, and that any other composition or lnsulatmg material may, if desired, be used.

The shell 0 is formed of a metal or metalllc alloy, which can be readily poured, say, an alloy having the composition z zinc 75%; aluminium 15%; copper 10%.

The plug is made as follows:

The .rod or, intended to serve as the axial electrode, is placed in a metal mold, similar to the molds used in glass making, (consisting of two shells d hinged togetherFigs. 2 and 3and provided with an internal cavity corresponding in shape to the shape desired for the insulating body 1)), and, when. the mold is closed, the sodium borosilicate is poured in through the gate 6 and is then compressed by means of a tamping iron f or by a press.

When this casting process has been completed, the insulating body I) is taken out of thief mold and the surplus material I) is out o Y The insulating body I), provided with the axial electrode a, and while in a plastic state is then placed in a second metal twopart mold 9 (Figs. 4 and 5), each member of which is furnished with a handle and fits one against the other, and provided with an shell to the insulating body, and as the metal of the shell contracts, on cooling, more than the material of the insulating body, the shell is held in closecontact with the said body'so that there is no possibility of leakage between the parts. Then again owing to the insulating body being hot when the shell is cast thereon, there is no likelihood of the insulating body being broken as would likely happen if the shell was cast on a cold insulating body.

As these two casting processes are effected while the -masses are hot during the entire operation, it will readily be understood that,

after cooling, the three constituent parts of the plug will be intimately united so asto form a single structure.

The shape and dimensions. of the various members of the improved plug, as Well as the materials of which they are made, may be modified.

Claims 1. The herein described process for manufacturing spark plugs, for explosion motors consisting in casting a glass insulator on a metal rod which forms an electrode and then immediately While the insulator is in a plastic state, casting a metal shell on the insulator.

2. The herein described process for manufacturing spark plugs for explosion motors, consisting in casting an insulating body formed of borax-silicate upon a metal rod which forms an electrode, and then immediately While the insulator body is in a plasti'c state, casting a metal shell upon the insulator body.

3. The herein described process for manufacturing spark plugs for explosion motors, consisting in casting an insulating body on a. metal rod which forms an electrode, and then immediately while the insulating body is in a plastic state, casting an alloy of zinc, aluminium andfcopper on the insulating body.

he foregoing specification of my improved sparking plu for internal-combustion engines and met 0d of manufacturing the same, signed by me this 27th day of J anuary 1919.

CHARLES EMILE GERBAUD.

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