FI68348C - FOERFARANDE FOER FRAMSTAELLNING AV MYNTAEMNEN - Google Patents

Description

I ·, * § * »· Ί ΓΒ1 m ADVERTISEMENT 68348

UTLÄGGNI NGSSKRIFT

99rfiX * C (45) Patent granted on 10 September 1985

Patent Meddelat; (51) Kv.ik.7int.CI. · a *** + C 21/00 (21) Patent application - Patentans & knlng 772658 (22) Filing date - Ansökningsdag 07.09.77 (EN) (23) Starting date - Giltighetsdag 07.09.77 ( 41) Become public - Blivit off e nti lg 05.05.78

National Board of Patents and Registration Date of publication and publication. - 31.05.85

Patent- och registerstyreisen '' Ansökan utlagd och utl.skriften publicerad (32) (33) (31) Pyydetty etuoikeus - Begärd priority 04.1 1 .76

German L i i ttotasava1ta-Förbundsrepubl i ken

Tyskl and (DE) P 265051 * 4.6 (71) Cable and Metallurgical Gutehoffnyngshutte Aktiengesel1schaft, Kabelkamp, 20, 3000 Hannover, Federal Republic of Germany

Franz Piegsa, Osnabruck, Federal Republic of Germany Förbundsrepubliken Germany (DE) (7 * +) Oy Kolster Ab (5 * 4) Method for making money blanks - Förfarande för f ramstäl In ing av myntämnen

The invention relates to a method for producing money blanks, in which the hoop or plate-like inner material is first metallurgically joined on both sides in the same way as hoop or plate-like coating material by rolling, injection molding, etc., the plate package is

To prevent counterfeiting, coated materials are increasingly being used today. This is based on the fact that counterfeiters usually find it difficult to manufacture or obtain coatings. Coated coins also have the advantage that the particularly advantageous properties of two or more metals can be combined in this way.

For example, coinage is known from DT 1 1574 275, which consists of a thin nickel core with a coating layer on both sides, which is a copper-nickel alloy containing about 25% nickel. Although this money can be distinguished from counterfeit money with relative certainty, it cannot be optically separated 68348.

DT patent 390 318 discloses a coated coin in which a spacer of a different color of metal is arranged between two metal plates of actual coin metal, by means of which the money can be optically separated from counterfeit coin.

Such money cannot be made in mass production, where metal blanks are stamped from a coated metal rim, because the stamping tools inevitably have a clearance, whereby the coating layer moves over the middle layer in the region of the peripheral surface. Because the coating material is often a mechanically stronger material, this rather thin layer does not wear out even in a longer circulation.

The object of the invention is to provide a method by means of which it is possible to produce money blanks which can be separated from counterfeit money in an optically simple manner after minting money and even after a longer circulation of money.

This object is solved by a method such as that mentioned at the beginning, so that the inner material and the coating material are, as is known per se, of different colors,

According to a particularly preferred embodiment, a copper alloy with about 2-6% nickel is used as the inner material and a copper alloy with 20-30% nickel is used as the coating material. This combination of substances has the advantage that the money made from it is automatically safe due to the conductivity of the inner substance, because they can be separated from magnetic substances and money with different electrical conductivity by means of a vortex current machine. The coating material copper-nickel 25 has long proven to be the best monetary material. An additional advantage of this combination of substances is that the recovery scrap can be reused to produce the same combination of substances. Since the nickel contents of 2-6% change the color of the copper very little, for example the copper alloy containing 25% nickel is silver-white in color, so that the money can be easily distinguished from counterfeit money due to clear color differences.

In addition, it has proved expedient to stamp money blanks with an oversize of about 0.05-0.2 mm. Namely, it has been found that the displacements occurring in connection with the stamping are of the order of a few tenths of a millimeter in diameter, so that the inner layer is visible from the center when the circumferential surface is cleaned later.

The invention is explained in more detail below by means of an exemplary embodiment.

Between the two preforms containing 25% nickel-containing copper-nickel alloy, a slightly smaller sheet preform of 2.5% nickel-containing copper alloy is placed, after which the contact surfaces between the different substances are cleaned. The plate package is heated to about 1050 ° C, after which it is rolled in several rolling steps to the desired final dimension. After cooling the plate, round blanks with a diameter of 23.1 mm are stamped on an automatic stamping machine and the diameters are turned to 23 mm in the next step. This turning can take place, for example, by combining the money blanks into a column, which is then turned on the circumferential side. The use of an automatic lathe has been found to be fit for purpose, where money is separated and turned one by one. After this, the money blanks are still piled and packed.

An essential advantage of the invention is that in a simple manner it is possible to produce counterfeit and other money which can be optically distinguished optically, the color differences on the circumferential side of which persist even after a long circulation.

Claims (4)

6834 8 A method of making money blanks, wherein the hoop or plate-like inner material is first metallurgically joined on both sides to the hoop or plate-like coating material by rolling, injection coating, etc., the sheet pack being optionally rolled to the desired money thickness, that the inner material and the coating material, as is known per se, are of different colors, that the money blanks are stamped with a small oversize and that they are then preferably machined from their circumferential surface by cutting to their final dimension. A method according to claim 1, characterized in that a copper alloy with about 2 to 6% nickel is used as the inner material and a copper alloy with 20 to 30% nickel is used as the coating material. A method according to claim 1 or 2, characterized in that the money blanks are stamped with an oversize of about 0.05 to 0.2 nuts. Method according to one of the preceding claims, characterized in that the money blanks are machined by turning or grinding.