US1250009A

US1250009A - Sparking plug.

Info

Publication number: US1250009A
Application number: US17269517A
Authority: US
Inventors: Theophile Elphege Ponsot
Original assignee: Individual
Current assignee: Individual
Priority date: 1917-06-04
Filing date: 1917-06-04
Publication date: 1917-12-11
Anticipated expiration: 1934-12-11

Description

T. E. PONSOT.

SPARKING PLUG.

APPLICATION r1150 JUNE 4.1917.

Patented Dec.11,'1917..

. Fig.5.

Fig-4 IA b. llrlwlfl INVAwroR T/zegnhle El /2. 51s Ponsaa plug.

THEOPHILE ELP HEGE PONSOT, OF-PARIS. FRANCE.

srnnxme PLUG.

Specification of Letters Patent.

Patented Dec. 11,191'7.

Application flled June 4,1917. s mino. 172,695.

To all whom it may concern:

Be it known that I, THEOPHILE ELPHEGE PoNso'r, a citizen of the Republic of France, and resident of Paris, in the Republic of France, have invented new and useful Iin-v provements in Sparking Plugs, of which the following is a specification.

The present, invention has for its :object a sparking plug which is of very simple con- 'struction, does not include any packing of asbestos or other material, and is constructed in such a manner as to permit not only good insulation of the central electrode but also cooling of the upper part of the plug, and more especially of this central electrode, by establishing an air current through the lug upwardly, and about the central electro e.

- The improved sparking plug is characterized essentially by a central electrodeinsulatedfrom the metal body at its lower part by an insulator sleeve in the form of a truncated cone fitting into the tubular part of the body which is of corresponding. form internally, and at its upper part bya hell or capof insulating material.

Apertures are formed in the body and at the upper part of the cap in a manner such as to enable air to circulate upwardly in the interior of the cap and cool the central electrode. The central electrode is also provided with a' head abutting against the insulating sleeve and protecting the same from the hot flames caused by the ignition, thereby increasing the life of the plug.

'The invention is shown by way of example in the accompanying drawing, wherein:

Figure 1 shows an elevation of my spark 1g. 2 is an under s de view of the same; and v Fig. 3 is a vertical section through the As shown, the sparking plug comprises a metal body o socket a provided with a screw threaded tubular part b which enables" the .plug to be fixed on an internal explosion engine. Thetubular part b is internally of the form of a truncated cone, of which the part of smaller diameter is arranged at the upper part of the member 6. In the tubular part b there fits an insulator sleeve 0 surrounding a rod (1 of the central electrode. The insulator sleeve chas a'lower'conical tfitting into the seat of the same shape ormed by the tubular'part b. It has also an upper cylindrical part projecting above cent end 0 the insulator sleeve 0.

the socket. The insulator sleeve 0 is formed by washers of mica fitted on to-the rod d which is already insulated by itsfitting into a tube 0 also of mica. The washers hear at the lower part of the rod (1 on a metal disk which may form an integral part of the rod or be retained thereon by a mushroom-head v d. The mica washers are tightened up in a press on the rod and are held in position on the rod 03 by a washer l of ivorine, fibrine or similar material, and also by a nut 10 which is threaded on the rod and which is embedded in the above mentioned material. A bell or cap -6 surmountsthe body a. It bears at its upperpart a nut o which is in threaded engagement with the rod 1) of the central electrode, and by means of which said cap is secured in place. The cap has a reduced end which fits into a recess a formed in the socket a. The rod receives also above the cap a Washer 17 and a lock nut 2. By reason of the height of the cap e the upper exposed part of the rod-d of the central elec-' trode is a considerable distance from the mass of metal formed by the body a, thereby preventing the production of external sparks when the end of the plug is subjected to high pressure in the interlor of the cylinder.

As mentioned above, the lower part of this central electrode is formed by a metal disk I: which has an inner inwardly tapering face, aainst which face abuts the adj a- This engagement ofthe end of the insulator sleeve 'with the disk protects the end of the elecface arranged on the same plane as the end A distance from the internal circumference of the tubular part b and'forming therewith a gap. The lower end of the insulator sleeve 0 1s provided over all of its periphery with a beveled surface'c? arranged in the opposite direction to the bevel is. These two bevels form an annular chamber (1 wherein residue from the combustion of the explosive mixture may lodge. This annular chamber hav-' ing a restricted inlet formed by the elec-' trodes prevents the high temperature present in the cylinder from entering into said chamber and affecting the end of the insulator which terminates therein.

In my improved sparking plug the internal air chamber formed in the body a is very deep and the holes 71 at the periphery of the body open at the base Oif this chamber. Moreover, the holes j formed in the cap 6 are arranged at the upper partof this cap. This arrangement causes an upward air current through the air chamber and about the upper part of the sleeve and the exposedportion of the central electrode located within the said. chamber.

From the above description it will be seen that the plug is formed of few parts which can be easily and quickly taken apart as, for example, by removing the nut p and washer the central electrode can be withdrawn with its insulator sleeve from the forms'a circular gapv with the wall of the upwardly tapering opening in the body, said circular sparking head tapering in the same direction as the opening but having a greater obliquity, whereby a chamber is formed by the tapers in the body, the circular head'and the lowerportion of the insulator sleeve.

2. In a spark plug, a metal body, a cen-' tral electrode having a circular sparking head presenting an inwardly tapering face,

an insulator sleeve having a tapering end engaging the tapering face of the head, said sleeve engaging the body, and means maintaining the end of the sleeve and face of electrode in firm contact, said sleeve and circular head forming a peripheral concave groove which, with the body, forms an annular chamber having a gap. t

3. In a spark plug, a metal body having a socket at its upper end, an insulator sleeve mounted in the lower part of the body projecting through the socket, a central electrode in the sleeve projecting above the same,

.and an insulator cap engaging the socket and the central electrode and secured by the latter, said insulator cap and socket forming an annular chamber about the sleeve, the top of the cap being spaced from the top of the sleeve whereby a portion of the central electrode is'in the said chamber, said chamber having openings in the lower and upper parts of the same whereby an air current is created therethrough and whereby the part of the electrode within said chambervis subject to the direct effect of the cool- I ing air current. .7)

4. In a spark plug, a central electrode, an insulator over the lower part of the electrode, and means forming a chamber about the upper portion of the insulator and the upper part of the electrode and secured by the latter, said chamber havin means for causing an upward air current t erethrough whereby the upper part of the electrode not covered by the insulator is subject to the cooling effect of the air current.

THEOPHILE ELPHEGE PONSOT- Witnesses CHAS. P. PiuassLY, GEORGES BRAUN.