US1375079A - of flint - Google Patents

Description

A. CHAMPION AND A. SCHMIDT.

SPARK PLUG.

APPLICATION FIL ED SEPT- 25; I9I8.

Patented Apr. 19, 1921.

INVENTORS (IIIJQPI: Champion By @IIIDQTJCQCILTYLICII W ATTORNEY.-

A UNITEDTSTATES PATENT OFFICE.

ALBERT CHA PIoN AND ALBERT SCHMIDT, I or FLINT, MICHIGAN, ASSIGNORS o CHAMPION IGNITION COMPANY, or FLINT, MICHIGAN, A CORPORATION OF MICH- IGAN. A

SPARK-PLUG.

Specification of Letters Patent. Patented Apr, 19, 1921.

Application filed September 25, 1918. Serial No. 255,582.

To all whom it may comm;

Be it known that We, ALBERT CHAMPION and ALBERT SCHMIDT, citizens of the United States, both residents of Flint, Genesee county, State of Michigan, have invented certain new and useful Improvements in Spark-Plugs, of, which the following is a specification.

Theinvention relates to improvements in spark plugs as described in the present specification and illustrated in the accompanying drawing that forms part thereof. One of the objects of the invention is to devise a spark plug which will be of simple construction and durable in operation.

Another object of the invention is to devise a spark lug which shall have the electrodeexposed to the products of combustion effectively insulated by a fireproof insulator, which shall be further protected and cushioned from fracture clue to anyvibration or shock. p 7

Another object of the invention is to devise a spark plug, the parts of which can be readilyassembled and clamped together as a unit with a feeling of assurance that the 1 several insulator parts are in perfect condition. I Y

Another object of the invention is to devise a sparkiplug having the central or sparking electrode properly proportioned to conduct heat from the firi-ng end and to further, provide a roper insulationand sealing electrode and surrounding parts. v v 7 Another object of the invention is to devise a spark plug in which the several insulator parts may be made of simple form and readily assembled.

'These' andother objects will more-clearly appear from the following description taken in connection with the accompanying draw- I in The drawing shows a vertical sectional view of the spark plug. 1' v Y Referrin to the drawing, 10 1s the shell of the spar plug, whichmay be of any deterior bore 11 and the lower part thereof forming a firing chamber with the interior bore 12, the exterior of the firing chamber being threaded as at 13 andthe exterior of the insulator chamber being formed with an extending portion, as at p 14, to receive a wrench.

The interior bore of the shell, where the chamber 11 is reduced to the chamber 12, is

' formed with the gasket seat 15 on which a gasket l6 formed of mica or other suitable material is placed preparatory to seating thereon the insulator 17, saidinsulator 17 being protected around the sides thereof by a 7 cylinder of mica 18 which forms a lining for the insulator chamber 11.

tomar to receive a terminal nut hereinafter descri ed.

The electrode 19 between the flange 20 and the top ofthe insulator 17 is provided I with a gasket or suitable compression washer 23, and also has the upper end thereof covered with the mica tube 24.

The space in theinsulator chamber 11 above the flange 20 of the electrode 19 is filled with mica washers 25, and covered with a follower plate 26 formed of metal and clamped firmly in position by any suitable means, that shown in the drawing being the flange 27 turned over the platefrom the upper edge of the shell 10.

The shell 10 is capped by a dome member 28,. having a central orifice 29 therethrough through which the electrode 19 extends, the terminal nut 30 being threaded onto the end of the electrode and firmly holding the dome 28 in position. v v

The operation of the plug whereby a spark is caused to jump between the terminals formed by the extreme lower end of the lower part 21 of the central electrode 19 and another electrode as 31 extending from the shell, will of course be well understood, and it is particularly desired to point out the peculiar nesting of the insulator element 17 in the shell.

It has been shown in actual practice that mica forms-an excellent insulator for the hightension current used in spark plugs, but when the mica is subjected to the heat and fire of the combustible gases within the 7 gasket material for sealing purposes, and

that the porcelain which'is exposed to the heat and fire of the combustion gases and forms the insulation for the lower and sparking end of the central electrode is comparatively very short and of block form to withstand all vibrations or shocks which will be received.

The insulator is further cushioned by the gasket or washer 23 and all the clamping action for securing the parts firmly together is directly received by the follower plate 26 and transmitted through the pile of mica discs 25 so that the lower and allimportant insulating member 17 is held with a degree of resiliency sufiicient to keep it whole and gastight.

The pile of mica discs is also the only efiicient means for filling the space between the upper part of the central electrode and the shell as the upper end of the electrode is ,made comparatively large to properly conduct heat away from the lower sparking end and this large electrode will not permit suflicient space for the use of a materialsuch as porcelain and have the same sufficiently strong to properly sustain the necessary sealing pressures. j

It will of course be understood that the mica cylinder 18 prevents any short-circuiting of the current from the flange 20 to the f shell 10, and likewise the mica tube 24: prevents any short-circuiting from the elctrode to the nearest point of the shell as atthe flange 27.

The dome 28 as described is a desirable finish for the upper part of the plug though it will of course be understood that the same is not necessary to asuccessful operation of the plug. 7

It will be obvious to thoseskilled in the art that many modifications and changes may be made without departing from the spirit and scope of the invention.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is end of said shell, and means for retaining place within said insulators and said electrode in said shell.

2. -A spark plug comprisinga shell, a central electrode, a porcelain insulator tip supported in said shell about the sparkin end of said electrode, a mica insulator filling within said shell above said porcelain insulator, a metal follower plate within said shell above said mica, and means for retaining said follower plate, said insulators and said electrode in said shell.

3. A spark plug comprising a shell, a central electrode, a porcelain insulator tip supported in said shell about the sparkin end of said electrode, a mica insulator filling within said shell above said porcelain insulator, and a metal follower plate within said shell above said mica and pressed upon by an inturned flange of said shell to compress said mica and porcelain insulators firmly into position in said shell.

4:. A spark plug comprising a shell having a tubular hnmg of insulating material, a central electrode having atubul'ar covering of insulating material, .an insulator tip sup-' ported within the lower portion of said shell about the sparking end of said electrode, a second insulator filling the space within said shell above said first mentioned insulator and the upper end of whichlies below the upper end of said shell, and means for retaining place Within said insulators and said electrode in said shell.

5. In a s ark plug, an electrode havin a tube of mica about the upper end an a porcelain insulator tip about the lower end thereof, a mica insulator body located above said porcelain insulator and surrounding said mica tube, and a cylinder of mica inclosinIg said mica and porcelain insulators.

6. n a spark plug, an electrode having a lateral flange intermediate the lengththereof dividing the same into an upper end and a sparking end, a tube of insulatin material about the upper end and a porce ain insulator tip about the sparking end ofsaid electrode, a' second insulator located above said porcelain insulator and surrounding said tube and between which two insulators said flange lies, and a cylinder of insulating material inclosing said two insulators and said flange. Y

7. In a device of the class described, in combination, 'a metallic shell havin a bore therethrough opening into a fire dliamber, a fire proof sparkin point insulator element fitting said bore ant closing thesame at the fire chamber end, a non-fract'urable insulator arranged in said bore and located "above said fire proof insulator and terminat ing below the upper end of said shell, and an electrode extending through passages provided in said two insulators.

8. Ina device of the class described, in

two insulators, and a dome surrounding the upper end of said electrode and through which said upper end extends, and the lower end of said shell.

9. A spark plug comprisin a shell having an insulator chamber an a fire chamber of reduced cross section, a cylinder of mica lining said insulator chamber, a fire proof sparking point insulator fitted in said insulator chamber and projecting into said fire chamber, an electrode having a lateral flange intermediate the length thereof abut ting said fire proof insulator and a sparking end extendin therethrough into said fire chamber, a tu e of mica inclosing the upper end of said electrode, a body of nonfracturable insulating material filling said insulator chamber between said tube and cylinder and retained therein in a compressed state, and a dome member capping said shell and having a central orifice throu h which said electrode extends.

10. n a spark plug, an electrode having the lower end thereof insulated by a fire proof insulator and the upper end thereof insulated by a non-fracturable insulator, said insulators being both surrounded by a non-fracturable insulating member which is in contact with a metallic supporting element. end of which dome abuts against the upper 11. A spark plug comprising a hollow metallic shell, an insulator of comparatively high heat resisting qualities supported in said shell adjacent the'lower end thereof, a central electrode supported in said insulator and having a comparatively large upper portion, and an insulator filling of nonfracturable material compressed into the space between the upper end of said electrode and said shell and which insulator filllllllg terminates below the upper end of said s ell.

In testimony whereof, we aflix our signa-

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