Method for manufacturing coins or medals

Abstract

To provide a coin or a medal with practicality, capable of constituting a permanent souvenir for a music event or the like.SOLUTION: A side view of a coin or a medal 2 having a circular outer edge 3 is shown three-dimensionally. A sound-recording band 6 and a center hole 8 are shown here. The spiral sound-recording band 6 is imprinted on the surface 4 of the coin or the medal 2. The spiral sound-recording band 6 is formed of a continuous groove without breaks similarly as a commercial record board, and the groove starts from the outer edge part of the coin or the medal 2 and continues up to a central blank area.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This invention relates to a method for manufacturing coins or medals.

Background Art

[0002] Coins and medals have long been used for commemorating kings and emperors alongside being a means of payment. The use of coins and medals as gifts for transmitting information is known from Patent Document 1. This is based on a memory medium (for example, a USB stick) formed inside a coin or medal. In that case, the surface of the coin or medal simply serves a decorative function.

[0003] A die corresponding to an impression formed only by lines of recesses arranged on a coin or medal is known from Patent Document 2. In that case, the color tone of the pattern to be impressed is formed by the distance between lines of recesses arranged extremely closely. The darkness of the color can be adjusted by the depth of the lines. Those lines of recesses arranged extremely closely are impressed by laser technology.

[0004] Audio media for music and voice recording are generally widely known. When such a recording tape is added onto a special media material, various application possibilities are achieved, such as a small record disc on chocolate as described in Patent Document 3. This utility model is configured to be playable by a commercially available record player.

[0005] Chocolate is an extremely fragile material and does not have high heat resistance. For example, when it is desired to use a small record disc as a souvenir, it is necessary to be based on a durable material.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] Accordingly, an object of the present invention is to provide the coin or medal described in the preamble of claim 1, which constitutes a permanent souvenir such as a music event and has practical utility.

Means for Solving the Problems

[0008] The above problems are solved according to the present invention by claim 1 or 17. Preferred additional configurations are defined by the dependent claims.

[0009] That is, the above problems are solved by the coin or medal described in the preamble of claim 1, which is configured such that a recording band is added to the surface by an appropriate stamping method. The recording band is preferably made readable using a commercially available record player or a playback device designed for coins or medals.

[0010] In particular, since coins include widely recognized symbols and are recognized by the entire human race, it is preferable to use them. Coins are the most widely used means of payment and are often used as omens.

[0011] The advantage of the solution according to the present invention is the long-term durability of the metal coin or medal, which can be a souvenir because it can be used for many years, has few external changes over time, is not easily damaged, and is easy to carry.

[0012] The recording band according to the present invention stamped on the surface of the coin or medal can be read even after a long time, and no change due to heat occurs unless it is heated to the melting point of the metal stored at normal temperature and intentionally used.

[0013] Another advantage of the coin or medal having the impressed recording band according to the present invention is that the coin or medal is formed from a solid metal, particularly a precious metal. Such metals are durable and aesthetically pleasing. Particularly suitable metals are gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), nickel (Ni), and metal materials plated with gold or silver. Other coated materials can also be used in the method according to the present invention.

[0014] Another advantage of the coin or medal having the impressed recording band according to the present invention is that, despite the small size of the coin or medal, an information content comparable to at least a single disc can be recorded on the surface. This is because higher stability of the recording band is achieved by the use of metal and thus it can be impressed at a higher density, that is, by selecting a smaller distance between individual recording grooves than in a conventional record disc. Furthermore, due to the density of the recording band and the associated information density, it is possible to select a low rotational speed such as 33 rpm of a conventional record player or an even lower rotational speed of a playback device designed for coins or medals.

[0015] It is highly preferable to use a recording band on a coin or medal in which grooves are impressed in a V-shape on the surface of the coin or medal, and the "V" has an inclination angle that is horizontal, that is, particularly 45° with respect to the surface of the coin or medal, which enables information recording of stereo recording.

[0016] According to a preferred additional configuration, the coin or medal is first processed to have as flat and smooth a surface as possible before the recording band is impressed. For this purpose, the coin or medal is loaded as a blank (circular blank) into a pressing space formed from a pressing ring having first and second pressing dies facing each other. The pressing ring and both pressing dies are formed from a pressure-resistant material.

[0017] It is preferable to perform the pressing at an extremely high pressure (about 200 tons to 800 tons) during the pressing process.

[0018] In a preferred embodiment, the first and second impression dies have extremely smooth surfaces facing the impression space. There is a master plate disposed between the blank in the pressing space and the first and / or second impression dies on at least one of the impression dies. This enables the simultaneous impression of the recording tape and the pattern on the surface of the coin or medal on the opposite side of the recording tape, and further enables the simultaneous impression with an extremely smooth surface, so-called mirror surface. It is also possible to impress a recording tape together with a pattern on one surface of a coin or medal, and to impress another pattern on the surface of the coin or medal on the opposite side of the recording tape.

[0019] In another preferred embodiment as well, the first and second impression dies have extremely smooth surfaces facing the impression space. There is a master plate depicting the negative image of the required pattern on one of both impression dies. This enables the impression of a pattern having an extremely smooth, that is, mirror-like surface. In a subsequent second impression step, a recording tape is impressed, optionally together with another pattern, on the surface of the coin or medal on the opposite side of the said pattern using another master plate.

[0020] In yet another embodiment as well, the first and second impression dies have extremely smooth surfaces facing the impression space. Here, no master plate is used yet in order to achieve an optimum density and the removal of unevenness (mirror surface) on the surface of the blank that may be present. In a second impression step, at least one master plate disposed between the blank in the pressing space and the first and / or second impression dies is used to impress an appropriate recording tape and / or a pattern on the surface of the coin or medal on the opposite side of the said recording tape.

[0021] It is also possible to make the master plate have a smaller diameter instead of the same diameter as the circular blank. This enables the impression of a structure such as a recording tape or a pattern without extending over the entire surface of the coin or medal.

[0022] It is highly preferable to use an imprinting space with an extremely small gap, particularly a gap of 0.02 mm, between the imprinting die and the imprinting ring. This ensures that the loss of raw materials is minimized as much as possible.

[0023] According to a preferred additional configuration of the solution according to the present invention, a master plate manufactured particularly by electroerosion is used.

[0024] Therefore, first, a resin layer made particularly of cellulose nitrate paint is provided on a metal plate. Similar to the case of a record disc, a recording track of the master plate is formed by engraving in the resin layer.

[0025] After that, a layer made particularly of a silver electrolytic deposit with a thickness of 4 to 5 μm is provided on that layer by electroerosion.

[0026] A very thin release agent is applied on the silver electrolytic deposit layer.

[0027] On that layer, a nickel layer with a thickness of particularly about 250 μm is provided by electroerosion, and it is then separated and functions as a master plate.

[0028] It is highly preferable to provide a central hole in the center of a coin or a medal to enable playback by a commercially available record player before or after both imprinting processes.

[0029] Another advantage of the solution according to the present invention is that the coin imprinted as described above can be used on a commercially available record player by disabling the automatic stop device.

[0030] Other details, features, and advantages of the present invention will be understood from the description of multiple embodiments of the present invention described below with reference to the accompanying drawings.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0032] Figure 1 shows a coin or medal according to the present invention having a circumferential outer edge 3 in plan view. The coin or medal according to the present invention has a diameter of about 50 mm to 150 mm, particularly about 100 mm. A spiral recording band 6 is impressed on the surface 4 of the coin or medal 2. Similar to a commercially available record disc, the recording band 6 is formed from a continuous groove without a break, which starts from the outer edge of the coin or medal 2 and continues to the central blank area. The central blank area of the coin or medal 2 where the recording band 6 is not impressed is essential because structurally the band cannot be read by a commercially available record player 12. It has a diameter of about 20 mm to 50 mm for a coin and 50 to 100 mm for a medal. However, when constructing a reading device for the unique coin or medal 2, it is also possible to configure the reading device so that the blank area is eliminated and the recording band 6 can extend to the center of the coin or medal 2. A central hole 8 is provided at the center of the coin or medal to enable playback by a commercially available record player. When selecting a reading device for the unique coin or medal 2, it is also possible to replace the central hole 8 with a recess or completely omit it through fixation by a turntable 20.

[0033] Figure 2 shows a three-dimensional side view of a coin or medal 2 having a circumferential outer edge 3 according to the present invention. Again, the recording band 6 and the central hole 8 are shown.

[0034] Figure 3 shows another three-dimensional side view of a coin or medal 2 having a circumferential outer edge 3 according to the present invention. Again, the central hole 8 is shown, but from the back side (the side of the coin or medal 2 opposite to the recording band). In addition, an exemplary pattern or relief 10 that can be impressed on the back side is shown.

[0035] Figure 4 is a schematic explanatory diagram showing an enlarged part of the recording band 6 impressed on a coin or medal. The surface 4 of the coin is formed of a material having durability and aesthetic appearance according to the present invention. Therefore, in particular, gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), nickel (Ni), and metal materials plated with gold or silver, or composite metals and precious metals such as iron have been proposed. In addition, in Figure 4, it is shown that the recording band 6 can extend linearly or in a wave shape. The "lateral" bending locus of the recording band 6 corresponds to the acoustic vibration of the recorded signal and can be converted into an acoustic signal by the tip of the recording needle 14 of the acoustic pickup 16 shown in Figures 5 and 6.

[0036] Figure 5 is a schematic explanatory diagram showing three-dimensionally a state where a coin or medal 2 having a built-in recording band 6 according to the present invention is placed on a turntable 20 of a commercially available record player 12 sketched, for example. The coin or medal is centered by inserting the central pin 18 of the record player 12 into the central hole 8 of the coin or medal 2. The recording band 6 can be converted into an acoustic signal by the tip of the recording needle 14 of the acoustic pickup 16.

[0037] Figure 6 is an explanatory diagram schematically showing a side surface of the recording band 6 impressed on a coin or medal 2, the recording needle, and the left coil 16a and the right coil 16b of the attached acoustic pickup 16. The depth of the recording band 6 can be utilized to enable vibration in the depth direction in addition to the lateral vibration. Thereby, it becomes possible to reproduce the work recorded on the recording band 6 in a stereo system, in which one channel is reproduced by vertical movement and the second channel is reproduced by horizontal movement. The groove of the recording band 6 has a "V" shape, and in particular, the inclination angle of the side is 45° with respect to the surface 4 of the coin or medal 2.

[0038] The dotted lines in Fig. 6 illustrate two possibilities where the depth of the recording band can change. Although shown on the left as an example, it is also possible to show it on the right instead. This does not cause a difference because all commercially available record players 12 are equipped with a left coil 16a and a right coil 16b of the acoustic pickup 16.

[0039] If the depth of the recording band 6 is changed simultaneously on both sides of the groove, the width of the recording band 6 will also change accordingly. However, if the width is to be maintained constant, the inclination angle of the side surface will inevitably change. In the case of a coin or medal 2, although the width of the recording band 6 can be changed, this requires a larger groove interval and thus affects the information density, so it is not suitable. The change in the inclination angle of the side surface symmetric or asymmetric with respect to the center point of the recording band 6 is effective when used together with the tip of the record needle 14 of the acoustic pickup 16 appropriately adjusted for a unique coin or medal 2 reading device. However, when using a commercially available record player 12 to play a coin or medal 2, the change in the inclination angle of the side surface with respect to the surface 4 must be excluded because such a change will deteriorate the reading by the tip of the commercially available record needle 14.

[0040] Fig. 7 shows a cross-section of the stamping space 22 having a stamping ring 24, a stamping die 26 composed of a first stamping die 26a and a second stamping die 26b, and a blank 28 of a coin or medal 2. It is extremely preferable that a small gap, particularly a gap of 0.02 mm, is formed between the stamping die 26 and the stamping ring 24 within the stamping space 22. By doing so, it is guaranteed that the material loss of the blank 28 is minimized as much as possible. In order to prevent the deformation of the blank 28 of the coin or medal 2 during the stamping process, it is ideal that the stamping ring 24 is extremely close to the blank 28 of the coin or medal 2. Due to this structure and the extremely smooth surfaces of the first stamping die 26a and the second stamping die 26b of the stamping die 26, ideal high density and elimination of the unevenness on the surface of the blank 28 that may exist in some cases can be achieved.

[0041] FIG. 8 is a cross-sectional view showing an embossing space 22 similar to that in FIG. 7, and further including a first master plate 30a and a second master plate 30b for embossing a pattern or relief 10 on the surface of a recording tape 6 and a coin or medal 2 on the side opposite to the recording tape 6, which together form a master plate 30.

Claims

1. A two-stage stamping method for manufacturing coins or medals, comprising loading a coin blank (28) into a stamping space (22) composed of a first and a second stamping die (26) which are opposed to each other, attached so as to be able to approach each other, and have smooth surfaces, and subjecting the coin blank to a pressure stamping of more than 200 tons in the first stage of the stamping process, and in the second stage of the stamping process, using at least one master plate arranged between the coin blank and the first and / or second stamping die in the stamping space to stamp an appropriate recording band as required. A stamping method characterized by this.

2. The stamping method according to claim 1, wherein the master plate (30) is smaller than the coin blank (28).

3. The stamping method according to claim 1 or claim 2, wherein a central hole (8) is provided in the center of the coin or medal (2).

4. In a method for manufacturing a master plate (30) for stamping a coin or medal (2) by electro-erosion, a resin layer made of cellulose nitrate paint is provided on a metal plate, a recording band of the master plate is formed by engraving in the resin layer, and then a layer made of silver electrolytic deposit with a thickness of 4 to 5 μm is provided on the resin layer by electro-erosion, an extremely thin release agent is applied on the layer made of silver electrolytic deposit, and a nickel layer with a thickness of about 250 μm is provided on the layer made of silver electrolytic deposit coated with the release agent by electro-erosion, and then the nickel layer is separated to obtain the master plate (30). An electro-erosion manufacturing method characterized by this.

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