COIN OR MEDAL

Description

[0001] Coins and medals have always been used, in addition to being a means of payment, to commemorate people from contemporary history and special events.

[0002] The classic method for producing coins or medals with embossed reliefs is cold forming blanks, also known as rounds. One such round and a process for cold forming are known, for example, from document DE 199 59 500 A1. This process involves cold forming to create a blank with a raised core and a raised edge zone on at least one side of the coin. However, this process only allows for the production of coins on a small scale, as the cold forming of the round requires extremely high pressures and a prolonged period of time. It is not possible to produce a relief with a particularly raised structure, a so-called high relief, i.e., a relief with a maximum height of more than 30% of the blank's thickness, and the relief-free surfaces of this coin are not particularly smooth.

[0003] Another method for producing coins or medals is a powder metallurgy process, known from DE 26 33 323. Using the powder metallurgy process, it is possible to achieve special material markings on the coin for the purpose of identifying counterfeits. This is achieved either by inhomogeneously distributing the materials in the blank or by adding a non-alloyable foreign substance. However, such processes have so far been of no importance in industry.

[0004] Coins or medals with a high relief and a powder metallurgical manufacturing process for a blank of such a coin or medal are known from the publication WO 2016 / 020234 A1. In this process, a metal powder is pressed into a plate-shaped or disc-shaped green compact with two opposing end faces by pressing dies. The green compact is then sintered to form the minting blank with a shape matching the green compact, with at least one side of the blank being at least partially provided with a profile. This profile can have a profile height of over 100% of the starting material thickness of the green compact. In practice, however, forming a high relief on both sides of the coin using a powder metallurgical process is not feasible.Very high pressures are required to fill all the fine details of a relief with the powder. This can only be achieved if the surface is smooth on one side and the powder is compressed into the three-dimensional relief on the other side using a flat press die. If there are reliefs on both sides, these pressures cannot be achieved in all areas.

[0005] The document JP H06 253912 A relates to a coin having a plurality of concentric rings according to the preamble of claim 1.

[0006] The publication AU 756424 concerns a coin with a hologram imprint.

[0007] The publication WO2017 / 063857 A1 concerns a circulation coin.

[0008] Document CN 209 862 543 U concerns a commemorative coin with an identification function.

[0009] However, it is not yet possible to create a high-relief coin or medal in combination with a very flat surface, the so-called mirror finish.

[0010] The invention is therefore based on the object of creating a coin or medal in order to create an exceptional and counterfeit-proof souvenir.

[0011] This problem is solved by a subject matter according to the independent claims. Advantageous further developments arise from the dependent claims.

[0012] This problem is solved by a coin or medal which has at least one three-dimensional relief which extends raised from a surface on at least one side of the coin or medal and is designed as a high relief. The surface, insofar as it is flat and relief-free, is very smooth (mirror finish) and has a roughness Ra of < 0.1 µm, in particular < 0.03 µm. The roughness Rz of the relief-free surface is below 1.0 µm, in particular below 0.3 µm. The relief-free surface has a gloss level at a measuring angle of 20° of over 900 GU, in particular over 1200 GU, and the roughness Ra of the relief-free surface is in the range between 5 nm and 30 nm.

[0013] The coin or medal is designed in such a way that the coin or medal has at least one three-dimensional relief extending across at least one side of the coin or medal, combining this with the so-called mirror finish in the non-relief areas. The highly smooth surfaces have a roughness Ra of less than 0.1 µm. The roughness Rz is less than 1.0 µm. It is particularly advantageous if the roughness Ra is less than 0.03 µm and Rz is less than 0.3 µm, thus achieving the highest possible degree of gloss (GU).

[0014] In an advantageous further development, the coin or medal with the (high) relief is made of solid metal, particularly a precious metal. Such a metal is both durable and aesthetically pleasing. Preferred metals are gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), and nickel (Ni), as well as gold- or silver-plated metal blanks. Plated blanks can also be used in a further embodiment. Alloys such as brass, bronze, and all CuNi alloys are also suitable.

[0015] A further advantage of the coin or medal with high relief is that the use of solid metals ensures a high stability of the relief, especially in very fine structures.

[0016] In a further advantageous development, it is possible to achieve relief heights of over 125% of the starting material thickness for starting materials (pure metals and alloys) from the group silver (Ag), copper (Cu), brass, bronze, and all CuNi alloys, and over 100% of the starting material thickness for starting materials (pure metals and alloys) from the group gold (Au), platinum (Pt), and palladium (Pd). This corresponds to relief heights that are 10-20 times higher than conventional reliefs and even exceed the heights of previously known high reliefs produced using powder metallurgy processes. The reliefs can be achieved not only on one but also on both sides of the coin or medal in combination with the so-called "mirror finish."

[0017] In an advantageous embodiment, the relief is distributed on both sides in a ratio of x:y = 1:1 (where x = relief height at the highest point on one side, y = relief height at the highest point on the opposite side). Other distributions, such as up to 3:1, are also conceivable. The ability to vary the height distribution of the reliefs enables the production of a multitude of different, alternative designs. To ensure that certain coins or medals display a high degree of individuality as commemorative items and are exceptional at first glance, the relief heights can be distributed across both sides of the coin. Human perception is particularly tactile, and an uneven distribution of the relief heights is immediately remembered as unusual and therefore individual.A high relief designed in this way in combination with a very smooth surface of the non-relief areas (mirror finish) enables the coin or medal to have a particularly high-quality appearance.

[0018] In a further advantageous development, it is intended to achieve a highly smooth surface with a gloss measurement value of over 1400 GU, in particular over 1200 GU, at a measurement angle of 20°. The flatness is preferably over 750 Rspec, in particular over 900 Rspec. These values ​​ensure that the surface of the coin or medal appears highly smooth in its smooth, relief-free areas and exhibits the so-called "mirror gloss."

[0019] In an exemplary coin or medal manufacturing process, the blank is placed in a press chamber consisting of a stamping ring with opposing first and second stamping dies. The stamping ring and both stamping dies are made of highly pressure-resistant material. The heated blank is subjected to a pressure of > 50 tons and held at this pressure for at least 1 minute, during which it cools.

[0020] The intensive deformation of the blank (round blank) can be facilitated by intermediate annealing. The first and second dies have a very smooth surface on the flat, i.e., relief-free areas facing the stamping chamber. This enables optimal compaction and the smoothing of any unevenness on the blank's surface. This enables a combination of a raised relief with the so-called mirror finish, a very smooth surface (gloss measurements > 900 GU (at a measuring angle of 20°), flatness > 750 Rspec) with a roughness of Ra < 0.1 µm, preferably < 0.03 µm, and Rz < 1.0 µm, preferably < 0.3 µm.

[0021] It is particularly advantageous to use a stamping chamber with a very small gap, particularly a gap of approximately 0.02 mm, between the stamping die and the stamping ring. This ensures that as little material as possible is lost.

[0022] Further advantages, details and features will become apparent from the following description of several embodiments of the invention with reference to the drawings.

[0023] They show: Fig. 1 shows a perspective view of a coin or medal with a three-dimensional relief of an exemplary motif, in a first embodiment; Fig. 2 shows a schematic representation of the side view of a coin or medal with two three-dimensional reliefs of an exemplary motif on each side of the coin or medal, in a further embodiment; and Fig. 3 shows a schematic representation of the cross-section of the minting chamber with minting ring with heating element, first and second highly smooth minting dies, and the blank of the coin or medal.

[0024] Fig.1 shows a perspective side view of a coin or medal 2 with a circumferential outer edge 4. The coin or medal has a diameter of approximately 10 mm to 100 mm. On the highly smooth surface 6 (mirror finish) of the coin or medal 2 there is a three-dimensional relief 8. The relief has a height of over 100% of the starting material thickness, in the exemplary embodiment 2 mm, and the mirror finish has a roughness Ra of less than 0.03 µm. The surface 4 of the coin is made of a durable and aesthetic material. According to the above explanations, the metals gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu) and nickel (Ni) as well as gold-plated or silver-plated metal blanks are proposed as being advantageous. In the present exemplary embodiment, a precious metal, namely silver (Ag), is used.

[0025] Fig. 2 shows a side view of the coin or medal 2 with a surrounding outer edge 4. The highly smooth surface 6 (mirror finish) of the coin or medal 2 as well as a three-dimensional relief 8 on each side of the coin or medal are again shown.

[0026] In Fig. 3A cross-section through the minting chamber 10 with minting ring 12 with heating element 20, first 14a and second 14b minting die 14 with high-relief negative 22, and the blank 16 of the coin or medal 2 is shown. It is particularly advantageous if a very small gap 18, in particular a gap of 0.02 mm, is created in the minting chamber 10 between the minting die 14 and minting ring 12. This ensures that as little material of the blank 16 as possible is lost. Ideally, the minting ring 12 lies very close to the blank 16 of the coin or medal 2 to avoid deformation of the blank 16 of the coin or medal 2 during the minting process. By means of this structure and the very smooth surface of the flat, i.e. relief-free areas of the first 14a and second 14b stamping dies 14, it is possible to achieve optimal compaction and the compensation of any unevenness on the surface of the blank 16.

Claims

1. A coin or medal having a circumferential outer edge (4), wherein the coin or medal (2) has at least one three-dimensional relief (8) which extends on at least one side of the coin or medal (2) from a surface (6) in an elevated protruding manner and is configured as a high relief, characterized in that the surface (6), insofar as it is flat and relief-free, has a high level of smoothness (mirror finish) and has a roughness Ra of <0.1 µm, in particular of <0.03 µm, wherein the roughness Rz of the relief-free surface (6) is below 1.0 µm, in particular below 0.3 µm, the relief-free surface (6) has a gloss level of more than 900 GU, in particular of more than 1200 GU, at a measuring angle of 20°, and the roughness Ra of the relief-free surface (6) is in a range between 5 nm and 30 nm.

2. The coin or medal as claimed in claim 1, characterized in that the coin or medal (2) consists of a disc of solid metal.

3. The coin or medal as claimed in claim 1 and claim 2, characterized in that the three-dimensional relief (8) is configured as a high relief and extends on both sides of the coin or medal (2).

4. The coin or medal as claimed in any one of the preceding claims, characterized in that the two three-dimensional high reliefs (8) opposite one another have different heights, in particular at the rate of x:y = 1.3:1 and x:y = 3:1 (wherein x = relief height at the highest point of the one side, y = relief height at the highest point of the opposite side).

5. The coin or medal as claimed in claim 1 to claim 4, characterized in that the two three-dimensional high reliefs (8) opposite one another have a height ratio of x:y = 1.3:1, in particular of x:y = 1.2:1, and preferably of x:y = 1:1.

6. The coin or medal as claimed in any one of the preceding claims, characterized in that the relief-free surface (6) has a flatness of more than 750 Rspec, in particular of more than 900 Rspec.

7. The coin or medal as claimed in any one of the preceding claims, characterized in that the coin or medal (2) consists of steel, precious metal, a precious metal alloy or non-ferrous metal or is silvered or gilded or plated with precious metal.

8. A production method for a coin or medal (2) as claimed in any one of the claims 1 to 7, in which a blank (16) is laid in a pressing chamber (10) which is built up of a coining ring (12) with opposite first and second coining stamps (14a, 14b) placed on top, and wherein the coining ring (12) and the two coining stamps (14a, 14b) consist of pressure-resistant material and the heated blank (16) is subjected to a pressure of more than 50 t and held at this pressure for at least 1 min, whereby it cools.