Patent Publication Number: US-2021170784-A1

Title: Coin or medal

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a coin or medal according to the preamble of claim  1  and to an embossing method according to the preamble of claim  17 . 
     Description of the Related Art 
     It has always been the case that coins and medals have been used not only as a means of payment but also to immortalise kings and emperors. The use of coins or medals as gift items to communicate information is known from DE 10 2004 033 356 A1. In that case a storage medium (for example a USB stick) is used which is incorporated into the interior of the coin or medal. The surface of the coin or medal serves in that instance for decorative purposes. 
     The embossing of motifs, which are formed only from arranged rows of depressions, on coins or medals and the associated embossing stamp are known from DE 601 02 007 T2. In that case, the colour shading of embossed images is generated by means of the distance between rows of impressions positioned very close together. The depth of colour can be adapted by the depth of the rows. These very closely positioned rows of depressions are engraved by means of laser technology. 
     Sound media for music and sound recordings are generally extensively known. Now, if these soundtracks are placed onto specific media materials, diverse application possibilities arise such as for example the miniature record made from chocolate described in DE 20 2008 003 639 U1. This is designed in such a way that it can be played by means of a commercially available record player. 
     Chocolate is a highly perishable material which also does not have a high level of temperature stability. Now, if it is desired to use a miniature record for example as a memento, it is necessary to use more stable materials. 
     SUMMARY OF THE INVENTION 
     Therefore, the object of the invention is to provide a coin or medal according to the preamble of claim  1  which forms a long-lasting memento for example for a musical performance, which also has a practical use. 
     In accordance with the invention, this object is achieved by claim  1  or  17 . Advantageous developments are apparent from the dependent claims. 
     This is achieved in that a coin or medal according to the preamble of claim  1  is provided which is designed in such a way that a soundtrack is applied to the surface by means of a suitable embossing method. This soundtrack should preferably be playable by means of a commercially available record player or a playback device developed for the coin or medal. 
     The use of a coin is particularly favourable since a widely used symbolism is inherent therein which is known to practically everyone. Coins are the most widely used means of payment and are often also used as lucky charms. 
     One advantage of the solution according to the invention is the longevity of metal coin or medal which can be a memento which is usable for many years, exhibits hardly any visible changes over time, is scratch-resistant and easy to transport. 
     The soundtrack in accordance with the invention, which is embossed into the surface of the coin or medal, is still playable even after years and does not undergo any temperature-induced changes provided it is subject to normal outdoor temperatures and there is no intention to heat it to the melting point of the metal used. 
     A further advantage of the coin or medal with an embossed soundtrack in accordance with the invention is that the coin or medal consists of solid metal, in particular of a noble metal. Such a metal is tough and also aesthetically appealing. Most preferred are the following metals: gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu) and nickel (Ni) as well as gilded or silvered metal blanks. Plated blanks can also be used in the method in accordance with the invention. 
     A further advantage of the coin or medal with an embossed soundtrack in accordance with the invention is that, despite the smallness of the coin or medal, the information content is at least comparable with what can be held on the surface of a single record. This is because the use of metals ensures a high level of stability for the soundtrack and this can therefore be embossed more densely, i.e. the distance between the individual sound grooves can be selected to be smaller than in the case of a conventional record. The density of the soundtrack and the resulting information density mean that furthermore a slow rotation speed of in particular 33 rpm of a conventional record player or an even slower speed of a player device made specifically for the coin or medal can be selected. 
     The use of a soundtrack on the coin or medal, the groove of which is embossed in a V-shape into the surface of the coin or medal, is particularly favourable, and this “V” has in particular an angle of inclination to the horizontal, i.e. to the surface of the coin or medal, of 45°, which permits the storage of information of a stereo recording. 
     In an advantageous development, provision is made that, before embossing of the soundtrack, the coin or medal is first processed in such a way that it has the most planar and smooth surface possible. For this purpose, the coin or medal is placed as a blank (round blank) in a pressing chamber which is formed from the embossing ring with mutually opposing, mounted first and second embossing stamps. The embossing ring and the two embossing stamps consist of a highly pressure-resistant material. 
     In the embossing step, embossing is preferably carried out at very high pressure (about 200 to 800 to). 
     In one advantageous embodiment, the first and second embossing stamps have a very smooth surface in the direction of the embossing chamber. On at least one of the embossing stamps are located dies which is/are placed into the pressing chamber between the blank and the first and/or second embossing stamp. This permits simultaneous embossing of the corresponding soundtrack and/or of the motif on the side of the coin or medal opposite the soundtrack, this side having at the same time a very smooth surface, the so-called mirror finish. It would also be possible to emboss a soundtrack with a motif on one side of the coin or medal and a further motif on the side of the coin or medal opposite the soundtrack. 
     In a further advantageous embodiment, the first and second embossing stamps again have a very smooth surface in the direction of the embossing chamber. A die which shows the negative of the desired motif is located on one of the two embossing stamps. This permits the embossing of the motif with a very smooth surface, the so-called mirror finish. In a second embossing step, by means of a further die, the soundtrack is then embossed, possibly with a further motif on the side of the coin or medal opposite the motif. 
     In a further advantageous embodiment, the first and second embossing stamps have a very smooth surface in the direction of the embossing chamber. In this case, in order to achieve optimal compacting and the smoothing out of any unevenness on the surface (mirror finish) of the blank a die is again not used. In the second embossing step, by means of at least one die which is/are placed into the pressing chamber between the blank and the first and/or second embossing stamp, the corresponding soundtrack and/or the motif is embossed on the side of the coin or medal opposite the soundtrack. 
     It is also possible for the die not to have the diameter of the round blank but to be smaller than it. This permits the embossing of structures—such as the soundtrack—or motifs which do not extend over the entire surface of the coin or medal. 
     The use of an embossing chamber in which there is a very small gap, in particular a gap of about 0.02 mm, between the embossing stamp and embossing ring is particularly favourable. This ensures that as little material as possible is lost. 
     In an advantageous development of the solution in accordance with the invention, the use in particular of a galvanically produced die is provided for. 
     For this purpose, a metal plate is first provided with a synthetic material layer of in particular nitrocellulose lacquer. As in the case of a record, the soundtrack of the die is introduced into this synthetic material layer by means of a stylus. 
     This layer is then galvanically provided with a layer of silver electrolyte, in particular 4-5 μm thick. 
     A very thin separating agent is applied to the silver electrolyte layer. 
     A nickel layer, in particular about 250 μm thick, is galvanically applied to this layer, it is then detached and serves as a die. 
     It is particularly favourable if the coin or medal is provided with a central hole in the centre before or after the two embossing processes in order to permit it to be played on a commercially available record player. 
     A further advantage of the solution in accordance with the invention is that the coin embossed in this way can be used on a commercially available record player with the automatic shut-off deactivated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages, details and features will be apparent from the following description of several exemplified embodiments of the invention with reference to the drawing. 
       In the drawings: 
         FIG. 1  is a schematic illustration of the top view of a first embodiment of a coin or medal in accordance with the invention with an integrated soundtrack; 
         FIG. 2  is a perspective illustration of a coin or medal in accordance with the invention with an integrated soundtrack in the embodiment according to  FIG. 1 ; 
         FIG. 3  is a perspective illustration of a further embodiment of a coin or medal in accordance with the invention showing an example of a motif which is embossed on the side of the coin or medal opposite the soundtrack; 
         FIG. 4  is a schematic illustration in detail of a part of the soundtrack embossed on the coin or medal; 
         FIG. 5  is a perspective illustration of a coin or medal in accordance with the invention with an integrated soundtrack as placed by way of example in a commercially available record player shown in sketch form; 
         FIG. 6  is a schematic illustration of the side view of the soundtrack embossed on the coin or medal in accordance with the invention and a schematic illustration of the point of a reproducing stylus of a sound pick-up used to pick up the soundtrack; 
         FIG. 7  is a schematic illustration of the cross-section of the embossing chamber with the embossing ring, first and second embossing stamps and the blank of the coin or medal in accordance with the invention; and 
         FIG. 8  is a schematic illustration of the cross-section of the embossing chamber with the embossing ring, first and second embossing stamps, blank of the coin or medal in accordance with the invention and the die used to introduce the soundtrack and/or the relief on the opposite side. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a top view of a coin or medal  2  in accordance with the invention with a circumferential outer edge  3 . A coin or medal in accordance with the invention has a diameter of about 50 mm to 150 mm, in particular about 100 mm. A spiral-shaped soundtrack  6  is embossed on the surface  4  of the coin or metal  2 . As in the case of a commercially available record, the soundtrack  6  consists of a continuous uninterrupted groove which extends at a small distance from the outer edge of the coin or medal  2  to the free surface in the middle thereof. This free surface in the middle of the coin or medal  2  in which there is no soundtrack  6  is necessary since this region, by reason of the design of a commercially available record player  12 , cannot be played and has a diameter of approximately 20 mm to 50 mm in the case of a coin and 50 to 100 mm in the case of a medal. However, if a dedicated playing device for the coin or medal  2  is made, it would be possible to make it in such a way that this free surface can be avoided and the soundtrack  6  can extend as far as the centre of the coin or medal  2 . A central hole  8  is provided in the centre of the coin or medal in order to render it playable using a commercially available record player. If, again, a dedicated playing device for the coin or medal  2  is chosen, it would be possible to replace this central hole  8  by a depression or even to avoid it altogether by a fixing arrangement using the turntable  20 . 
       FIG. 2  shows a perspective side view of a coin or medal  2  in accordance with the invention with a circumferential outer edge  3 . Again, the soundtrack  6  and the central hole  8  are shown. 
       FIG. 3  shows another perspective side view of a coin or medal  2  in accordance with the invention with a circumferential outer edge  3 . In this illustration, the central hole  8  is again shown but now from the rear side (the side of the coin or medal  2  opposite the soundtrack). Furthermore, an example of a motif or relief  10  can be seen which can be embossed on this side of the coin. 
       FIG. 4  is a schematic illustration in detail of a section of the soundtrack  6  embossed on the coin or medal. In accordance with the invention, the surface  4  of the coin consists of a material which is tough and also aesthetically appealing. For this purpose the following are proposed, inter alia, especially the non-ferrous and noble metals: gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu) and nickel (Ni) as well as gilded or silvered metal blanks, but also steel. Furthermore,  FIG. 4  shows that the soundtrack  6  can extend straight or in an undulating manner. The way the “lateral” deflection of the soundtrack  6  extends corresponds to the acoustic oscillation of the stored signal and can be converted into an acoustic signal by means of the tip of a reproducing stylus  14  of a sound pick-up  16  illustrated in  FIG. 5  and  FIG. 6 . 
       FIG. 5  shows a schematic perspective view of the coin or medal  2  with an integrated soundtrack  6  in accordance with the invention as placed by way of example on the turntable  20  of a commercially available record player  12  shown in sketch form. The centre spindle  18  of the record player  12  therefore centres the medal or coin  2  on the turntable  20  by passing through the central hole  18 . The soundtrack  6  can be converted into an acoustic signal with the aid of the tip of a reproducing stylus  14  of the sound pick-up  16 . 
       FIG. 6  shows a schematic illustration of the side view of the soundtrack  6  embossed on the coin or medal  2  and a schematic illustration of the reproducing stylus  14  with the associated left  16   a  and right  16   b  coil of the sound pick-up  16 . The depth of the soundtrack  6  can be used to permit an additional depth movement in addition to the sideways movement. It is therefore possible to reproduce the piece embossed in the soundtrack in stereo, wherein one channel is characterised by the vertical movement, the second by the horizontal movement. The groove of the soundtrack  6  is of a “V” shape, in particular with an angle of inclination of the flanks of 45° with respect to the surface  4  of the coin or medal  2 . 
     The broken lines in  FIG. 6  show examples of options for varying the depth of the soundtrack. This is shown by way of example on the left side but the right side can also be described instead of this. This makes no difference since a commercially available record player  12  has a left  16   a  and a right  16   b  coil in the sound pick-up  16 . 
     If the depth of the soundtrack  6  is varied on both sides of the groove at the same time, the width of the soundtrack  6  therefore changes or—if the width is kept constant—the angle of inclination of the flanks necessarily changes. A change in the width of the soundtrack  6  is feasible in the case of a coin or medal  2  but is not worth attempting since it requires greater spacing of the grooves and therefore influences the information density. A change in the angle of inclination of the flanks symmetrically or even asymmetrically with respect to the centre point of the soundtrack  6  is favourable when using a dedicated playing device for the coin or medal  2  with a correspondingly adapted tip on the reproducing stylus  14  of the sound pick-up  16 . However, in order to play the coin or medal  2  by means of a commercially available record player  12  it would be necessary to dispense with a change to the angle of inclination of the flanks with respect to the surface  4  since such a change impairs the playing by the tip of a commercially available reproducing stylus  14 . 
       FIG. 7  illustrates a cross-sectional view through the embossing chamber  22  with an embossing ring  24 , first  26   a  and second  26   b  embossing stamps  26  and the blank  28  of the coin or medal  2 . It is particularly favourable if a very small gap, in particular a gap of 0.02 mm, is provided in the embossing chamber  22  between the embossing stamp  26  and embossing ring  24 . This ensures that as little material of the blank  28  as possible is lost. Optimally, the embossing ring  24  lies very closely against the blank  28  of the coin or medal  2  in order to avoid deformation of the blank  28  of the coin or medal  2  during the embossing process. By means of this structure and the very smooth surface of the first  26   a  and second  26   b  embossing stamps  26  it is possible to achieve optimal compaction and smoothing out of any unevenness on the surface of the blank  28 . 
       FIG. 8  shows the same cross-sectional view through the embossing chamber  22  as in  FIG. 7  but in this case additionally the first  30   a  and second  30   b  dies  30 , one for embossing the soundtrack  6  and one for embossing the motif or relief  10  on the side of the coin or medal  2  opposite the soundtrack  6 .