Europaisches Patentamt 0163 419 J European Patent Office Publication number: B1 Office europeen des brevets

EUROPEAN PATENT SPECIFICATION

C 25 D 3/58, Date of publication of patent specification: 05.10.88 © intci.4: C 25 D 7/00, A 44 C 21/00 Application number: 85302932.0 Date of filing: 25.04.85

thereof. Aureate , medallions and tokens and method for the production

Sherritt Gordon Mines Limited Priority: 01 .05.84 CA 453305 Proprietor: 2800 Commerce Court West Toronto, Ontario (CA) Date of publication of application: 04.12.85 Bulletin 85/49 Inventor: Ruscoe, Michael J.H. 36 Gresham Boulevard Publication of the grant of the patent: St. Albert Alberta (CA) 05.10.88 Bulletin 88/40 Inventor: Seibt, Willie 10172-88th Street Edmonton Alberta (CA) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE Representative: Lambert, Hugh Richmond et al D. YOUNG & CO. 10 Staple Inn References cited: London, WC1V7RD(GB) WO-A-84/03522 FR-A-743797 GB-A-1558 803 US-A-2886500

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Note- Within nine months from the publication of the mention of the grant of the European patent, any person may of shall qive notice to the European Patent Office of opposition to the European patent granted. Notice opposition deemed to have been filed until the opposition fee has been Q. be filed in a written reasoned statement. It shall not be 99(1 ) convention). Ul paid. (Art. European patent Courier Press, Leamington Spa, England. 0 163 419 Description vending equipment which only accepts magnetic coins. A further problem is that a blank must This invention relates to aureate coins, be readily mintable, i.e. it must be soft enough to medallions or tokens and blanks used for the be readily deformed by coin dies during the production of coins, medallions or tokens, that is 5 minting procedure to impart the required insignia to say metal blanks or minted coins, medallions to the coin faces. The coin blanks must not be too or tokens having a golden appearance, and a hard, otherwise the costly coin dies would wear method for the production thereof. out too quickly or an undesirable shallow impres- Many countries are replacing or planning to sion would be produced on the struck coin. This is replace bank notes by coins, mainly because bank 10 undesirable since coin dies are expensive. notes are expensive forms of compared It is therefore an object of the invention to to coins in view of the relatively short life of bank provide an aureate coin which overcomes the notes. Bank notes are thus not desirable as low above mentioned problems, that is to say an value currency, and inflation is of course resulting aureate coin which is relatively inexpensive to in bank notes in many countries now representing 15 produce, has a satisfactory service life with low value currency. It is bank notes of such low respect both to acceptable colour and other physi- value currency that are being replaced by coins. cal properties such as wear, is suitable for use in It has become established in many countries coin-operated vending equipment with coin that low value coins have a copper colour, and validation devices which check physical that middle and high value coins have a silver 20 properties including electrical and nagnetic colour. In the past, solid gold coins have been properties, and is not easily counterfeited. used for relatively high value currency, but today According to the invention, a coin, medallion or are struck only for the numismatic value or as a token product (i.e. a minted coin, medallion or convenient form of bullion. However, gold is now token or blanks used for the production of coins, so expensive that a present day gold coin would 25 medallions or tokens) has a coin-shaped core with necessarily comprise a base metal core with a opposed faces and a peripheral side edge of very thin gold coating, perhaps only 1-2 urn. The mintable metallic material, and an electroplated, small gold thickness would be likely to wear coating comprising copper and tin completely through to the base metal core during the normal encasing the core and providing a long lasting service life of the coin and the intrinsic value of 30 golden appearance in use. The electroplated coat- the gold would be lost. ing contains from about 8 to about 16% tin by From GB-A-1 558803 the electroplating of coin- weight, preferably from about 11 to about 14% shaped cores with Cu is known. Alloying with the balance being copper. The electroplated elements may be included in said upper coating coating has a thickness on each core face of from to increase wear of corrosion resistance, but no 35 about 10 to about 150 urn, preferably from about particular hint is disclosed to tin. The thickness of 30 to about 50 urn. The total weight of the the coating is preferably 0.05 mm or 0.14 mm. electroplated coating may be from about 2 to Various attempts have been made to produce about 26%, preferably from about 6 to about 10%, satisfactory inexpensive aureate coins for use as of the total weight of the product. relatively high value currency. Brass, typically 40 Also provided in accordance with the present 70% copper and 30% zinc, is a common yellow invention is a method of producing such blanks coinage alloy, but it tarnishes in service and is and coins, medallions or tokens. thus associated with cheapness in the public eye. Although it is known to electroplate metal An attempt has recently been made to overcome articles such a door handles with an alloy of this problem by replacing 5% of the zinc with 45 copper and tin to produce a bronze finish, bronze nickel, but the resulting colour is a pale yellow of the composition described, particularly at the rather than gold. In another attempt, an alloy high end of the tin range, is well known to be a composition of 92% copper, 6% nickel and 2% hard alloy which cannot be readily rolled or aluminium has been used, but this composition worked into strip form, i.e. which cannot normally has a pink hue and tends to turn brown in service. so be worked into a coinage product. Thus, bronzes Other attempts have also been made with other in the above composition range would not alloy compositions but none has had a long normally be considered for use as coinage lasting satisfactory golden appearance. materials. Also, considering the relatively high Another problem with common yellow coins of cost of tin, such high tin alloys would not solid low melting point brass and bronze is that 55 normally be considered for coinage. they are easy to counterfeit. Still another problem In accordance with the present invention how- is that a coin must have acceptable physical ever, it has been discovered that a coin, medallion properties, such as weight, size and electrical and or token product as described above has an magnetic properties, for use in coin-operated acceptable long-lasting aureate appearance, i.e. is vending equipment having coin testing devices 60 satisfactorily resistant to tarnishing, and with which rely on such properties to distinguish a suitable choice of core material is readily - required coin from other coins and fraudulent able and has suitable properties for acceptance by replicas of the required coin. For example, the conventional coin selection devices in vending nickel-modified brass coin mentioned above is machines. A coin, medallion or token product in non-magnetic and hence will not be accepted by 65 accordance with the invention is also inexpensive 0 163 419 to produce and has a satisfactory service life. an alkaline copper-tin plating bath containing Also, compared to coins with a homogeneous about 32 g/L copper and 26 g/L tin. The tempera- composition, a coin, medallion or token product ture of the bath was 75°C, and a voltage of 6.25 V in accordance with the invention is not readily was applied giving a current of 431 A. After 3.6 h, counterfeitable. 5 the barrel was removed from the plating bath and Coin, medallion or token blanks in accordance passed through a cold rinse and an anti-stain with the invention may for example be produced rinse. in barrel-plating equipment in the manner After plating, the blanks were found to have a described in Canadian patent No. 1,093,498, copper-tin electrodeposit equal to 9.1% of the issued January 13, 1981 and the corresponding io weight of the plated blank. The tin content of the United States patent No, 4,089,753 issued May 16, deposit was 13.0%, with the balance being cop- 1978, using a suitable copper-tin electroplating per. The thickness of the electrodeposit was 43 bath. um on the faces and I05 urn on the side edge. As mentioned above, the metallic core material The plated blanks were then passed to a pro- should be readily mintable, chosen for low cost, is duction annealing furnace with a temperature provide specific properties for coin selection setting of 750°C and a hot zone retention time of devices, and for optimum protection against 12 minutes to reduce their hardness from about counterfeiting. The core material may for 78 to about 32 on the Rockwell 30T hardness example comprise iron, steel or stainless steel, scale. Annealed blanks were then cleaned, nickel, nickel-plated steel, zinc, copper or various 20 polished and brightened in a two-stage process alloys of copper containing zinc and/or nickel and/ comprising acid washing followed by detergent or tin. It is also recognised that if given a suitable burnishing. Burnished blanks were then minted pretreatment, cores of aluminium or aluminium using chromium plated dies, and produced alloys may be used. bright, shiny, golden yellow coloured coins. In some cases, the core is advantageouslv 25 Although the major proportion of the foregoing annealed, before or after plating, to give the blank description has been concerned with coins, it will a satisfactory low hardness for minting. Anneal- be noted that the invention is equally applicable ing after electroplating is also advantageous in to medallions or tokens. The scope of the inven- that it can be used to create a metallurgical bond tion being defined in the appended claims. by interdiffusion between the electroplated cop- 30 per-tin coating and the core material. If the core Claims material is already soft enough for minting, as with zinc, annealing may be omitted. 1. A coin, coin blank, medallion, medallion A further advantage is that coins, medallions or blank, token or token blank comprising a coin- tokens in accordance with the invention have a 35 shaped core of mintable metallic material, and an relatively low friction surface which renders them electroplated coating completely encasing the relatively easy to extract from coin minting collars core, characterised in that said electroplated coat- after striking. ing has a thickness on the opposite faces of the Tests have shown that aureate coins in accord- core of from 10 to 150 um, and contains from 8 to ance with the invention and having a nickel core 40 16% tin and the balance copper. may have similar physical properties (including 2. A coin, medallion or token, or a coin, magnetic properties) to nickel or nickel-plated medallion or token blank according to claim 1, steel coins for which coin vending devices have wherein the electroplated coating contains from been designed, and hence may replace such prior 11 to 14% tin and the balance copper. coins without any changes being necessary to the 45 3. A coin, medallion or token, or a coin, coin vending devices. Furthermore, aureate coins medallion or token blank according to claim I or 2, having specially selected core materials consist- wherein the thickness of the electroplated coating ing principally of alloys of copper, zinc and nickel of the opposite faces of the core is from 30 to 50 have been shown to have a discrete and unique um. response in modern electro-magnetic coin 50 4. A coin, medallion or token, or a coin, - vending devices, thus providing high security lion or token blank according to claim 1, 2 or 3, against counterfeiting. wherein the weight of the electroplated coating is Production of aureate coins in accordance with from 2 to 26% of the weight of the total product. the invention and having nickel cores will now be 5. A coin, medallion or token, or a coin, described by way of example. 55 medallion or token blank according to claim 4, wherein the weight of the electroplated coating is Example from 6 to 10% of the weight of the total product. A batch comprising 25 kg of rimmed solid nickel 6. A coin, medallion or token, or a coin, blanks was loaded into a perforated, rotatable, medallion or token blank according to any one of horizontal plating barrel of length 91 cm and 60 claims 1-5, wherein the core comprises iron, steel, diameter 36 cm. The barrel was then passed stainless steel, nickel, nickel alloy, zinc, zinc alloy, through a cleaning cycle consisting of rinses in copper, copper alloy or aluminium or aluminium hot alkaline detergent, hot water, cold water, 10% alloy suitably pretreated to permit the elec- HCI and again in cold water. trodeposit of said coating thereon. After the final rinse, the barrel was immersed in 65 7. A coin, medallion or token, or a coin, 0 163 419 medallion or token blank according to any one of dadurch gekennzeichnet, daft der Kern Eisen, claims 1-6, wherein the electroplated copper-tin Stahl, rostfreien Stahl, Nickel, Nickellegierung, coating is metallurgically bonded to the core by Zink, Zinklegierung, Kupfer, Kupferlegierung oder interdiffusion. Aluminium oder Aluminiumlegierung, die in 8. A coin, medallion or token according to any 5 geeigneter Weise vorbehandelt sind, um die Gal- one of claims 1-7 comprising a core which has vanisierung der Beschichtung daran zu ermogli- been electroplated with said copper-tin coating to chen, enthalt. form a copper-tin coated blank, and which has 7. Munze, Medaille, Zahlungswertmarke oder then been minted. Miinzen-, Medaillen- oder Zahlungswertmarken- 9. A method for the production of an electro- w rohling nach einem der Anspruche 1 bis 6, plated coin, medallion or token blank, which dadurch gekennzeichnet, daft die elektroplattierte comprises electroplating a coin-shaped core of Kupfer-Zinn-Beschichtung metallurgisch mit dem mintable metallic material, characterised in that Kern durch Interdiffusion verbunden ist. said core is electroplated with an aureate copper- 8. Munze, Medaille oder Zahlungswertmarke tin alloy containing 8 to 16% tin, and the balance is nach einem der Anspruche 1 bis 7, gekennzeich- copper, to a thickness of from 10 to 150 urn on the net durch einen Kern, der mit der Kupfer-Zinn- opposite faces of the core. Beschichtung elektroplattiert worden ist, um 10. A method according to claim 9, wherein the einen Rohling mit einer Kupfer-Zinn-Beschich- copper-tin alloy, or the thickness or amount tung zu bilden, und der dann gepragt worden ist. thereof, is as required by any one of claims 2-5. 20 9. Verfahren zur Herstellung eines elektroplat- 11. A method according to claim 9 or 10, tierten Munzen-, Medaillen- oder Zahlungswert- wherein the core is of metal or alloy as required markenrohlings, das das Elektroplattieren eines by claim 6. munzenformigen Kerns aus pragbarem Metall- 12. A method according to claim 9, 10 or 11, material umfaftt, dadurch gekennzeichnet, daft wherein after electroplating the electroplated 25 der Kern mit einer goldfarbenen Kupfer-Zinn- blank is annealed. Legierung, die 8 bis 16% Zinn und als Rest Kupfer enthalt, auf eine Oicke von 10 bis 150 um, an den Patentanspriiche einander entgegengesetzten Flachen des Kerns elektroplattiert wird. 1. Miinze, Munzenrohling, Medaille, Medaillen- 30 10. Verfahren nach Anspruch 9, dadurch rohling, Zahlungswertmarke oder Zahlungswert- gekennzeichnet, daft die Kupfer-Zinn-Legierung markenrohling mit einem munzenformigen Kern oder deren Dicke oder deren Menge der Bestim- aus einem pragbaren Metallmaterial und mit mung nach einem der Anspruche 2-5 entspricht. einer den Kern vollstandig einhullenden elektro- 11. Verfahren nach Anspruch 9 oder 10, plattierten Beschichtung, dadurch gekennzeich- 35 dadurch gekennzeichnet, daft der Kern aus einem net, daft die elektroplattierte Beschichtung an den Metall oder einer Legierung nach der Bestim- einander entgegengesetzten Flachen des Kerns mung des Anspruchs 6 besteht. eine Dicke von 10 bis 150 urn hat und B bis 16% 12. Verfahren nach Anspruch 9, 10 oder 11, Zinn sowie als Rest Kupfer enthalt. dadurch gekennzeichnet, daft nach dem Elektro- 2. Munze, Medaille, Zahlungswertmarke oder 40 plattieren der elektroplattierte Rohling gegluht Miinzen-, Medaillen- oder Zahlungswertmarken- wird. rohling nach Anspruch 1, dadurch gekennzeich- net, daft die elektroplattierte Beschichtung von 11 Revendications bis 14% Zinn und als Rest Kupfer enthalt. 3. Munze, Medaille, Zahlungswertmarke oder 45 1. Piece de monnaie, flan de piece de monnaie, Miinzen-, Medaillen- oder Zahlungswertmarken- medaillon, flan de medaillon, jeton ou flan de rohling nach Anspruch 1 oder 2, dadurch gekenn- jeton, comprenant un noyau en forme de piece de zeichnet, daft die Dicke der elektroplattierten monnaie en une matiere metallique susceptible Beschichtung an den einander entgegengesetzten d'etre frappee, et un revetement electroplaque Flachen des Kerns 30 bis 50 urn betragt. 50 enveloppant completement le noyau, caracterisee 4. Miinze, Medaille, Zahlungswertmarke oder en ce que le revetement electroplaque a une Munzen-, Medaillen- oder Zahlungswertmarken- epaisseur sur les faces opposees du noyau de 10 rohling nach Anspruch 1, 2 oder 3, dadurch a 150 um et contient de 8 a 16% d'etain et le gekennzeichnet, daft das Gewicht der elektroplat- restant etant du cuivre. tierten Beschichtung 2 bis 26% des Gewichts des 55 2. Piece de monnaie, medaillon ou jeton, ou flan Gesamtprodukts betragt. de piece de monnaie, de medaillon ou de jeton, 5. Munze, Medaille, Zahlungswertmarke oder selon la revendication 1 selon laquelle le revete- Munzen-, Medaillen- oder Zahlungswertmarken- ment electroplaque contient de 11 a 14% d'etain rohling nach Anspruch 4, dadurch gekennzeich- et le restant etant du cuivre. net, daft das Gewicht der elektroplattierten eo 3. Piece de monnaie, medaillon ou jeton, ou flan Beschichtung 6 bis 10% des Gewichts des de piece de monnaie, de medaillon ou de jeton, Gesamtprodukts betragt. selon la revendication 1 ou 2, selon laquelle 6. Munze, Medaille, Zahlungswertmarke oder I'epaisseur du revetement electroplaque des Munzen-, Medaillen- oder Zahlungswertmarken- faces opposees du noyau est de 30 a 50 urn. rohling nach einem der Anspruche 1 bis 5, 65 4. Piece de monnaie, medaillon ou jeton, ou flan 0 163 419 8 selon de piece de monnaie, de medaillon ou de jeton, 8. Piece de monnaie, medaillon ou jeton, selon la revendication 1, 2 ou 3, selon laquelle le I'une quelconque des revendications 1 a 7, com- poids du revetement electroplaque est de 2 a 26% prenant un noyau qui a regu par depot electrolyti- former du poids du produit total. que ledit revetement de cuivre-etain pour 5. Piece de monnaie, medaillon ou jeton, ou flan 5 un flan revetu de cuivre-etain et qui a ensuite ete de piece de monnaie, de medaillon ou de jeton, frappe. selon la revendication 4, selon laquelle le poids 9. Une methode de production d'un flan de du revetement electroplaque est de 6 a 10% en piece de monnaie, ou de medaillon ou de jeton- forme poids du produit total. ,qui consiste a electropiaquer un noyau en 6. Piece de monnaie, medaillon ou jeton, ou flan io de piece de monnaie en une matiere metallique de piece de monnaie, de medaillon ou de jeton, susceptible d'etre frappee, caracterisee en ce que de selon I'une quelconque des revendications 1 a 5, ce noyau est electroplaque avec un alliage 16% le selon laquelle le noyau comprend du fer, de cuivre-etain dore contenant 8 a d'etain, de 10 I'acier, de I'acier inoxydable, du nickel, un ailiage restant etant du cuivre, a une epaisseur a de nickel, du zinc, un alliage de zinc, du cuivre, un 15 150 urn sur les faces opposees du noyau. selon alliage de cuivre, de I'aluminium ou un alliage 10. Une methode selon la revendication 9, d'aluminium prealablement traite de maniere laquelle I'alliage de cuivre-etain, ou son epaisseur I'une quel- appropriee pour permettre le depot electrolytique ou sa quantite, est comme requis par dudit revetement. conque des revendications 2 a 5. 7. Piece de monnaie, medaillon ou jeton, ou flan 20 11 . Une methode selon la revendication 9 ou 10, de piece de monnaie, de medaillon ou de jeton- selon laquelle le noyau est en un metal ou un ,selon I'une quelconque des revendications 1 a 6, alliage comme requis par la revendication 6. selon laquelle le revetement electroplaque de 12. Une methode selon la revendication 9, 10 ou le cuivre-etain est lie metallurgiquement au noyau 1 1 , selon laquelle, apres le depot electrolytique, recuit. par interdiffusion. 25 flan electroplaque est

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