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Publication numberUS2470033 A
Publication typeGrant
Publication dateMay 10, 1949
Filing dateNov 27, 1945
Priority dateNov 27, 1945
Publication numberUS 2470033 A, US 2470033A, US-A-2470033, US2470033 A, US2470033A
InventorsHensel Franz R
Original AssigneeMallory & Co Inc P R
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Spark plug
US 2470033 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

May 10, 1949c F. R. HENsEL SPARK PLUG Filed Nov. 27, 1 945 ATTO RNEY man May 10,1949 2,470,033

2,470,033 SPARK PLUG Franz R. Hensel, Indianapolis, Ind., asslgnor to I P. R. Mallory & Co., Inc., Indianapolis, Ind., a corporation of Delaware Application November 27, 1345, Serial No. 631,205

2 Claims. l This invention relates to spark plugs. An object of the invention is to improve spark plug electrodes.

Other objects of the invention will be apparent from the description and claims.' 5 rapidly from the sparking tip.

111th@ draWngI l Palladium is a highly satisfactory electrode Figure 1 shows a portion of a Spark plug, partly material and approaches platinum in its perin section, illustrating the spark plug electrodes; formance. As disclosed in U. S. Patent 2,335,821

Figure 2 is an "enlarged longitudinal section of to E. M. Wise et al., a fairly heavy plate of palamOdiCaiOn f the electrodes; and l0 ladium can be produced in accordance with the Figure 3 is another electrode combination ,of following bath composition and conditions: the present invention.

The invention contemplates a spark plug with auadnlm as PdC}2"' 50 grams per mer mmonium chloride-- to 50 grams per liter nickel electrodesl having a roughened surface Temperature 50., C and all B lectrodeposfed coating of platinum or 15 Current density-:llt: l0 amperes per square foot palladium base materials. A .tation Air lift Before deposition of the precious metal coatg1 y ing, the surface of the nickel electrode is rst BY using Prepared palladium allOdBS the 00m roughened by such means as etching, sand blastposition of the bath is maintained and there is ing, knurling, or any other suitable method. gg) no necessity for replenishing. Smooth ductile The purpose of this roughening is to create sharp deDOSiS Carl be made at a rapid rate. DBDOSS protrusions which will promote corona discharge 0f .025 have been made in 16% hOlllS- When or lower the sparking voltage when the plug plating upon Such metals aS'niCkel, C0DD1',10I1 is fired. and silver a preliminary strike from a low metal Nickel is destroyed rather rapidly by spark 2j ion concentration bath of palladium, gold, platierosion. According tothe present invention the 1111111, rhodium 01 Other noble mel/91S iS Preferadvantages of a roughened surface is obtained ably depostedrsttogether with good resistance to spark erosion The use of a palladium plate maybe 921111011- by use 0f a deci-,Tomate of platinum or pallarly desirable for side electrodes, with the palladium base material over the roughened nickel. ladium thickness being -010 Inch- The gap The resulting electrode structure and composigrowth in Spark plug eleCtIOdeS OCCUI'S p01? Only tion has a, long nie and 10W and Consistent Sparkon the center electrode but also on the side elecing voltage. trode. A combination of a palladium plated In Figure 1, the center electrode may comprise nickel Side electrode Versus a tungstn 01' tun?- a cylindrical section ll of nickel or nicke1 base 35 Sten alloy Center electrode results 1n supenol metal tip `welded to the end of a nickel, nickel performance and decreased sap growth. alloy, iron ahoy or copper alloy rod l2 which is Figure 3 shows a combination of a center elecembedded in the ceramic insulator I3 of the trod@ tip 45 0f tungsten 01 tungsen allOy Weldil spark plug. The roughened Working surface of to an electrode `rod 40 with a side electrode tip the electrode is coated With an electrodepOsit i0 0f r0ughened-mcke1 2| eletroplated Wlth mail# lt of palladium or platinum. The side electrode mlm 01 Dalladlum 24- may b'e produced in a like manner with a, rough- The palladium may also be used for platingy ened nickel tip 2l, electroplated with a palladium the Center electrode. The base of the electrodes or platinum base metal 24 and welded into a may be either nickel ora nickel a1l0y,ora copper nickel, iron or copper alloy rod 22 which is Welded 45 O1 Silver COIed nickel. The electrode can be to the metal shell i5 of the plug. If either one masked in such a manner that only the areas or both of the electrodes are wholly composed of at which actual sparking occurs are electroplatednickel, the electrode rod may be formed of one Platinum may be electrodeposited from compiece of nickel, which obviates the necessity of plex sodium platinate baths or from phosphate, welding the electrode tip. sulfate or nitrite ammine baths.

The electrode may be made of a nickel-iron Instead of platinum and palladium it is also alloy, containing 42% nickel, for example, whose possible to electroplate `alloys of such metals. coefficient of expansion is lower than that of pure This may be accomplished by codeposition of the nickel or of high nickel alloys, and approximates alloying elements or by plating the elements onto the coeflicient of expansion of platinum. each other and forming the alloys by a diffusion (Cl. 12s-169) 2 Figure 2 shows a modiflcation of the spark plug electrode which, .besides the roughened nickel 3l and the palladium plate 34, contains a copper or silver core 33 to conduct heat away process such as heating the plated assembly in a non-oxidizing atmosphere.

These alloying methods may be employed to form platinum-palladium, platinum-rhodium or palladium-rhodium alloys. Suitable palladiumchromium and platinum-chromium alloys can be formed by electrodeposition. Other'alloying elements for platinum or palladium are nickel, manganese, copper, silver and gold, all of which lend themselves to electrodeposition. i

The palladium or platinum plated roughened nickel electrodes of the present invention when used in automotive or aircraft spark plugs have the advantage of withstanding the erosive action of the spark resulting in gap growth. YHence, frequent adjustment of electrodes is obviated. Also the sharp protrusions of the roughened nickel promote a corona discharge which lowers the sparking voltage. Thus, a spark plug containing one or both electrodes as described in the present invention effectively increases the efllciency of automotive, aircraft or stationary engines.

While specic embodiments of the invention have been described, it is intended to cover the invention broadly within the spirit and scope of the appended claims.

What is claimed is:

1. A spark plug comprising a pair of spaced electrodes, one of said electrodes 'being formed 4 predominantly of tungsten and at least the sparking area of the other electrode being formed predominantly of nickel the surface of which has been roughened, and an electrodeposited coating of palladium over said nickel surface.

2. A spark plug comprising a pair of spaced electrodes, at least the sparking areas of said electrodes being formed ofnickel the surface of which has been roughened, and an electrodeposited coating of palladium over said nickel surface, the surface of said electroplated coating conforming to the configuration of the said nickel surface.


REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date y 1,445,712 'Reiinhout Feb. 20, 1923 2,028,749 John et al Jan. 28, 1936 2,296,033 Heller Sept. 15, 1942 2,391,455 Hensel Dec. 25, 1945 FOREIGN PATENTS Number Country Date 163,786 Great Britain May 24, 1921 206,532 Great Britain Nov. 5, 1923

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1445712 *Dec 10, 1919Feb 20, 1923Reijnhout Jan PieterSparking plug for internal-combustion engines
US2028749 *Dec 4, 1929Jan 28, 1936Carbex Chemical Co Of IllinoisSpark plug
US2296033 *Jan 18, 1941Sep 15, 1942Gen Motors CorpSpark plug
US2391455 *Jun 22, 1943Dec 25, 1945Mallory & Co Inc P RSpark plug and electrode therefor
GB163786A * Title not available
GB206532A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2916667 *Aug 23, 1957Dec 8, 1959Dale Products IncLightning arrester
US3143684 *Oct 27, 1959Aug 4, 1964Texas Instruments IncComposite metallic electrode material and electrodes made therefrom
US3351541 *Jan 19, 1965Nov 7, 1967Gen ElectricElectrodeposition of the platinum metals
US3444003 *Sep 30, 1965May 13, 1969Leesona CorpMultilayer catalytic electrode having a layer of noble metal and lead and a surface layer free of lead and method of constructing same
US3527680 *Dec 14, 1964Sep 8, 1970Rolls RoyceCatalytic igniter members
US3562574 *Jul 25, 1968Feb 9, 1971Wesoloski Henry JArticles plated with or comprised of silver-palladium alloys
US3829969 *Nov 5, 1970Aug 20, 1974Gillette CoCutting tool with alloy coated sharpened edge
US3854067 *Oct 4, 1973Dec 10, 1974Phillips Petroleum CoSpark plug
US3958144 *Nov 22, 1974May 18, 1976Franks Harry ESpark plug
US4093887 *Nov 4, 1976Jun 6, 1978Robert Bosch GmbhSpark plug, particularly for internal combustion engines having composite center electrode
US4540910 *Nov 17, 1983Sep 10, 1985Nippondenso Co., Ltd.Spark plug for internal-combustion engine
US4771209 *Mar 22, 1984Sep 13, 1988Champion Spark Plug CompanySpark igniter having precious metal ground electrode inserts
US4906889 *Jun 20, 1988Mar 6, 1990Fred DibertSpark plug construction with temperature responsive ground wires
US8534041Dec 23, 2009Sep 17, 2013Unison Industries, LlcApparatus and assembly for a spark igniter having tangential embedded pins
DE2530368A1 *Jul 8, 1975Jan 20, 1977Friedrich Von Dipl StutterheimSpark plug for IC engines - has central electrode and earthed electrode made from base metals, alloys or composite materials with refractory metal portions
DE3036223A1 *Sep 25, 1980Apr 30, 1981Champion Spark Plug CoFunkenzuender
DE4431143B4 *Sep 1, 1994Sep 23, 2004Robert Bosch GmbhZündkerze für eine Brennkraftmaschine
WO1996007226A1 *Aug 16, 1995Mar 7, 1996Richard AdamczukSpark plug for an internal combustion engine
WO2008082716A2 *Aug 28, 2007Jul 10, 2008Federal Mogul CorpIgnition device electrode composition
U.S. Classification313/142, 427/437, 205/257, 313/11.5, 205/216, 205/259, 428/612, 205/118, 313/311, 313/140, 428/665, 205/206, 428/670
International ClassificationH01T13/39
Cooperative ClassificationH01T13/39
European ClassificationH01T13/39