US1719389A

US1719389A - Spark plug for internal-combustion engines

Info

Publication number: US1719389A
Application number: US196956A
Authority: US
Inventors: Colin Rene
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-06-06
Filing date: 1927-06-06
Publication date: 1929-07-02
Anticipated expiration: 1946-07-02

Description

Jlily 1929. R. COLIN SPARK PLUG FOR INTERNAL COMBUSTION ENGINES Filed June 6, 1927 I l I Patented July 2, 1929.

PATENT OFFICE.

RENE COLIN, OF STRASBOUBG, FRANCE.

' seam: PLUG ron INTERNAL-COMBUSTION madness.

Application filed June 6,

This invention relates to a spark plug for internal combustion engines, which is arranged in such a manner, that the action of the spark plug and the explosion of the cylinder can he observed from the outside.

For this purpose certain parts of the spark plug are made of transparent materials.

This characteristic permits observation of the functioning of the'spark plug as well as the explosion directly from the outside, without it being necessary. to unscrew the spark plug. As the observations are made while the spark plug is in place, control is naturally much more effective. Several forms of the subject-matter of the invention are shown in the drawings.

Fig. 1 is a section through a complete'spark plug.-

Fig. 2 a sect-ion through another form of spark plug. v

Fig. 3 a section through the special form ofv an electrmle for the spark plug.

The spark plug of the ordinary style consists of a body 1, a central screw 2, in which 25 is arranged the central electrode 3. which latter is surrounded by an insulating body 4 of mica or the like, and at both ends, of the screw provided with insulating discs 5 and 6 of mica or the like. Between the inner ft) abutment of the body 1 and the threaded portion of the screw 2 a tubular piece 7 of transparent insulating or not insulating material is arranged so that the flame of the explosion in the cylinder, which flame extends up into the inner hollow space of the spark plug,

sion of which compensates for the different" 1921. Serial No. 196,956.

expansion coefiicients, in order to guarantee the absolute tightness of the spark plugs during use.

One can also use a socket, consisting of transparent material and which at necessary points is surrounded by a metal sleeve; It is 5 also possible to form the electrode itself wholly or partly of transparent or semitransparent material.

Fig. 3 for instance shows a section through an electrode permitting the observation of 65 the spark plug from the outside. The electrode consists in this case of a tube 10, having at its upper portion a thread for receiving the necessary access'ories- At the opposite end, however, are provided one or several abutment-s 11 serving for the transmissions of the spark to the socket portion in the usual manner. The inside of this tube 10 is filled by a transparent bodyenabling observation from the outside.

Such transparent or semitransparent parts of the spark plug can be manufactured of the various insulating or noninsulating materials available.

Having thus described my invention what I claim is:

A spark'plug comprising a body having an observation opening in its wall, a transparent insulating member in said body andextending across said observation opening,

an electrode extending through said transparent insulating member and a screw sleeve threaded in said body andarranged to secure said insulating element in place, the wall of said screw sleeve being of such thickness as to provide an annular space extending to said insulating element and form a darkened observation zone through which sparks which illuminate said insulating member may be observed.

In witnes 's whereof I afiix my signature.

- RENE COLIN.