Bimetallic coin and blank for a bimetallic coin

Abstract

Bimetallic coin or blank for a bimetallic coin with an inner disc-shaped part (1) and a concentric outer ring-shaped part (2) which are permanently joined to form a composite, as well as an electrically insulating insulating layer (3) arranged concentrically between the inner disc-shaped part (1) and the outer ring-shaped part (2) in a form-fit and force-fit manner, wherein the insulating layer (3) has translucent properties, consists of a composite material made of an organic base material and contains inorganic color pigments.

Description

[0001] The invention relates to a two-part coin consisting of an inner disc-shaped part – disc / pill – and a concentric outer ring-shaped part – ring. Both parts are positively and non-positively connected to each other and are typically made of different solid alloys and / or multilayer metallic materials.

[0002] The invention further relates to a blank for a bimetallic coin.

[0003] Bimetallic coins have increasingly been introduced into international circulation as currency denominations. In civilian commerce, this facilitates the identification and differentiation of coins of different denominations with similar characteristics, such as size, shape, and weight, particularly through color differences, and increases security against the intentional or accidental use of counterfeit coins. A variety of metals and alloys are now used for bimetallic coins, combined in the form of discs and rings. In particular, copper alloys of the types CuNi, CuAlNi, CuZnNi, CuSn, CuZn, and CuAlZnSn, with or without further alloying elements, as well as stainless steels, especially ferritic steels, are used as solid, electroplated, or plated coin materials. Special procedures and devices are available for the detection and verification of the authenticity of each coin used in vending machines.For this purpose, the inductive and electromagnetic target / actual parameters of the coin materials and material combinations used for the respective denominations are primarily compared as they pass through the coin validator. Accordingly, the test for bimetallic coins is also performed for both materials; that is, the significant parameters for the ring and the disc are recorded and compared with the target values ​​stored in the coin validator. This enables a high degree of detection and differentiation of foreign coins and counterfeits. However, in the interface area between the ring and the disc of a bimetallic coin, very wide measurement tolerances and errors due to manufacturing-related differences from coin to coin cannot be ruled out with many coin validators. These differences can be found, among other things, in the contact resistance between the ring and the disc.The resulting variation in measurement results can ultimately lead to bimetallic coins not being correctly recognized by the coin acceptor and being erroneously accepted as "OK" or rejected as "not OK". Even when handling bimetallic coins manually, purely visual confusion with foreign coins or confusion between denominations due to insufficient differences in size, engraving, and color nuance cannot be ruled out. Electrochemically induced corrosion effects at the interface between the ring and the disc result in undefined contact resistances. This effect is more pronounced the greater the potential difference between the metals and alloys used for the ring and disc.

[0004] The object of the invention is to provide a bimetallic coin that increases the security of testing the electronic measurement parameters in coin-operated machines, that permanently ensures a defined contact resistance between ring and disc, that enables improved visual recognition in normal hand-to-hand circulation and that excludes electrochemical corrosion effects at the interface between ring and disc.

[0005] According to the present invention, the problem is solved by the subject matter of claim 1. inventive solution

[0006] According to the invention, a bimetallic coin, consisting of an inner, disc-shaped part that is not exclusively circular but may also exhibit variations in diameter distributed around its circumference (scallop) – referred to as the disc – and a concentrically arranged outer, ring-shaped part – referred to as the ring – has an electrically insulating layer – referred to as the insulating layer – between the disc and the ring, which is permanently bonded to the disc and the ring in a form-fitting and force-fit manner. The insulating layer consists of a polymer or a composite material that is thermally stable in the temperature range typical for coins and can withstand temperatures above 150 °C, and which is preferably characterized by transparent, semi-transparent (translucent), opalescent, and / or colored effects.The electrically insulating layer according to the invention has a width of preferably 0.5 to 3.0 mm between the disk and the ring. However, other widths of the insulating layer are also possible. A sulfur-containing polymer, in particular a polysulfone (PSU), or an etherketone-containing polymer, in particular a polyetheretherketone (PEEK), is preferably used as the polymer. An organic base material doped with an inorganic material is used as the composite material. Preferably, color pigments, UV stabilizers, fluorescent components, and / or particles with holographic properties are used as inorganic dopants. According to the invention, a fracture-resistant, amorphous silicate or ceramic base material is also used as the composite material. Other non-conductive materials are also possible.

[0007] The inventive solution includes, in principle, blanks for bimetallic coins, medals and similar bimetallic coins.

[0008] The invention will be explained in more detail below using three exemplary embodiments. The following are designated in relation to the bimetallic coin according to the invention: 1 - Ring, - outer ring-shaped part 2 - disc, - inner disc-shaped part 3 - Insulating layer, - electrically insulating layer between ring and disk Example 1:

[0009] Fig.Figure 1 shows a bimetallic coin consisting of a ring 1 made of CuNi25 and a disc 2 made of a three-layer plated material nickel-brass / nickel / nickel-brass. The diameter of the disc 2 is 1.5 mm smaller than the inner diameter of the ring 1. An insulating layer 3 made of the amorphous and transparent polymer polysulfone is arranged concentrically in the resulting gap, forming a positive and force-fit connection. This transparent insulating layer 3 ensures high electrical insulation between the ring 1 and the disc 2, thus guaranteeing error-free identification of the bimetallic coin in coin-operated machines by completely eliminating measurement errors in the transition area between the ring 1 and the disc 2. The insulating layer can also be optically detected as an additional measuring feature. Furthermore, the transparency of the insulating layer 3 provides excellent optical and visual coin recognition. Example 2:

[0010] Fig.Figure 2 shows a bimetallic coin of the same construction. It consists of a ring 1 made of stainless steel, a disc 2 made of a CuAlZn alloy and a 0.5 mm wide insulating layer made of a semi-crystalline polymer, namely polyetheretherketone, which has a light brown color and is not transparent, i.e., opaque to light. Example 3:

[0011] Fig. Figure 3 shows a bimetallic coin of the same construction, consisting of ring 1, disc 2 and insulating layer 3. The insulating layer 3 is a composite material consisting of a transparent polymer polysulfone, which is doped with 3 wt.% fluorescent fibers, so that conspicuous luminescent effects in UV light can be used as a distinguishing feature.

Claims

Bimetallic coin or blank for a bimetallic coin with an inner disc-shaped part (1) and a concentric outer ring-shaped part (2) which are permanently joined to form a composite, as well as an electrically insulating insulating layer (3) arranged concentrically between the inner disc-shaped part (1) and the outer ring-shaped part (2) in a form-fit and force-fit manner, wherein the insulating layer (3) has translucent properties, consists of a composite material made of an organic base material and contains inorganic color pigments. Bimetallic coin or blank for a bimetallic coin according to claim 1, wherein the insulating layer (3) is thermally resistant above 150°C. Bimetallic coin or blank for a bimetallic coin according to one of the preceding claims, wherein the width of the insulating layer (3) between inner disc-shaped part (1) and outer ring-shaped part (2) is 0.5 to 3.0 mm. Bimetallic coin or blank for a bimetallic coin according to claim 1, wherein the composite material further comprises UV stabilizers or fluorescent components and / or particles with holographic imaging. Blank for a bimetallic coin according to one of the preceding claims, wherein the insulating layer (3) is deformable by a minting process for the production of a coin. Bimetallic coin according to one of claims 1 to 4, wherein the composite of inner disc-shaped part (1) and outer ring-shaped part (2) has an embossing.

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