Classifications

• • A—HUMAN NECESSITIES
  • A44—HABERDASHERY; JEWELLERY
  • A44C—PERSONAL ADORNMENTS, e.g. JEWELLERY; COINS
  • A44C21/00—Coins; Emergency money; Beer or gambling coins or tokens, or the like

Definitions

• the present invention relates to a method, according to the preamble of Claim 1, for manufacturing a coin, medal, or similar formed from two different materials.
• the invention also relates to an arrangement intended to implement the method and a product manufactured with its aid.
• Coins manufactured from at least two different materials have been in use for a long time.
• the best-known examples in Europe are the one and two-euro coins.
• metals and metal alloys shape plastically under load, the components made from different alloys can be attached to each other by compression, in such a way that either the ring forming the hole, or the centre to be placed in the hole in the centre of the coin shapes radially under pressure.
• a plastically shapable material tends to flow to fill the space reserved for it, the compression can take place from the upper or lower surfaces of the coin, so that the ring and centre tighten against each other as the mould becomes filled.
• Publication CN 1236584 discloses a method for manufacturing a bimetal coin. In it, a tongue and groove combination is formed in the ring and centre made form different metals, and the pieces are pressed together.
• the present invention is intended to create a method for manufacturing a coin formed from at least two different materials, in which the centre of the coin is manufactured from a material that cannot be shaped plastically, such are stone, ceramic, or glass.
• the invention is based on a ring of a plastically shapable material being stamped and pressed using a mandrel stamp, in such a way that the ring is shaped to a set dimension and an opening equipped with a bevel is formed in the middle of it.
• the centre which is of a material that cannot be shaped plastically, is pressed into this bevelled opening, in such a way that the centre is wedged tightly into the opening by the bevel of the opening.
• the coin according to the invention is characterized by what is stated in the characterizing portion of Claim 10.
• the medal, coin, or commemorative medal being made can be of proof quality or with a normal polish and it can have a hole of precisely the desired shape.
• the hole can be, for example, shaped like the map of Finland. This will make such medals very distinguished and dignified.
• a symbolism linking a coin or medal to a specific place or event can be attached to it.
• a symbolism linking a coin or medal to a specific place or event can be attached to it.
• the centre of a coin from the stone symbolizing each province in Finland, i.e. it so-called provincial stone it is possible for each province to obtain its own typical commemorative coin or medal.
• Figure 1 shows one ring blank and centre for a coin according to the invention.
• Figure 2 shows a mandrel stamp for manufacturing a ring blank according to the invention.
• Figure 3 shows the ring blank during compression in the mandrel stamp of Figure 2.
• plastic shaping refers to the material's yielding in such a way that permanent deformations arise in it, without the material breaking.
• the yield limit of plastic materials is lower than their ultimate limit, i.e. the material can be shaped without fracturing.
• Brittle materials i.e. materials than cannot be plastically shaped, do not have a yield limit that appears before the ultimate limit, but instead breaking occurs without substantial permanent deformation, once the ultimate limit is exceeded. A piece made from the material will then break.
• One definition of a material that is brittle or cannot be plastically shaped can thus be that a piece manufactured from the material will break before yielding.
• the name coin is used for a product according to the invention, for reasons of simplicity.
• the invention relates to all similar reasonably thin objects, in which there are two relatively extensive faces oriented opposite to each other, and an edge that rounds around them.
• the names of these can be, for example, coins, medals, and commemorative medals or decorations.
• Figure 1 shows schematically a centre 1 made of a brittle material being placed in a ring 2 shaped for it.
• the outer edge 5 of the centre is straight.
• the ring 2 is shaped in the manner described above to correspond to the dimensions of the coin and in it is also formed the desired stamped patterns.
• In the outer edge of the ring 2 there is a raised edging 3.
• the hole 4 in the ring 2 is shaped at an angle, in such a way that its greatest diameter is slightly greater than the diameter of the centre 1 and its smallest diameter is correspondingly smaller than the diameter of the centre 1.
• both the centre 1 and the ring 2 are symmetrical around their axis of rotation.
• the ring 1 made of a shapable material and forming the outer circumference of the coin is shaped beforehand to set dimensions and it is stamped prior to the attachment of the centre 1. Because the ring 2 cannot be shaped after, or during the attachment of the centre, no great stresses act on the brittle centre and the centre 1 can be attached in place without damage.
• the ring 1 is formed by stamping from a ring blank from a suitable metal alloy, or possibly from an unalloyed metal, using a mandrel stamp according to Figure 2.
• the ring can be made from available coinage alloys.
• the mandrel stamp comprises the actual mandrel stamp 6, inside which a mandrel 7 is fitted.
• the edges 9 of the cup part of the mandrel stamp 6 form a stamp for the side of the coin that comes first and in it there is the desired pattern for the stamp.
• the above construction includes an upper stamp 11, which closes mould formed by the edges 9 of the mandrel stamp 6, the stamp ring 10, and the mandrel 7.
• the pressing of the ring of the coin to the set dimensions and the stamping are shown schematically in Figure 3.
• the ring 2 is preferably manufactured from a normal numismatic ring blank.
• the stamping of the ring takes place, for example, using a numismatic stamping machine, using the mandrel stamp described above.
• the blank can be stamped using some other device as a mandrel stamp, but using a numismatic stamping machine will ensure the quality of surface and pattern necessary for valuable and collectors' coins.
• the ring blank is placed in the mandrel stamp, when its first side comes against the edge 9 of the mandrel stamp.
• the hole in the centre of the blank is now greater than the diameter of the mandrel 7, so that the point of the mandrel 7 will fit into the hole in the blank.
• the blank forms into the shape of the mould space of the mandrel stamp, according to Figure 3.
• the bevel 4 according to the point 12 of the mandrel is formed in the hole in the blank, and the patterns, for example a text and shield, according to the stamps 6, 11 are formed in the upper and lower surfaces.
• the pattern, for example milling, according to the stamp ring 10 is formed in the outer edge.
• the mandrel moves down as the elastomer 8 flexes and its height from the upper surface of the ring 9 of the mandrel stamp becomes the same as the distance between the ring 9 of the mandrel stamp and the upper stamp.
• the bevel of the point 12 of the mandrel always settles to the same point when pressed by the upper stamp, so that the hole in the blank is always shaped in the same way and the shape of the hole will be precise. This is of primary importance, because if the shape and size of the hole vary, it will not be possible to attach a centre made of brittle stone or other similar material without breaking it.
• the centre If, for example, stone, ceramic, or glass with a thickness of about 2 mm is used as the centre, and if its diameter is about 25 mm, the largest diameter of the hole in the ring will be 25.50 ⁇ 0,05 mm and the smallest 25.20 ⁇ 0,05 mm. The precise dimensions of the centre would then be 25.35 ⁇ 0.05 mm. As can be seen on the basis of the tolerance in the example, the shape of the metallic blank must be quite precise. To achieve the precision of the hole, the use of the elastomer 8 is essential, because the point of the mandrel is then always guided in the same way according to the upper stamp and the blank can easily be shaped, because the point of the mandrel 7 does not determine the position of the upper stamp.
• the mandrel can also be made fixed, but in that case the very high precision requirements may become a problem, which will increase the manufacturing costs of the ring blank.
• the flexing of the elastomer prevents the ring blank from catching on the point of the mandrel and the stamping ring and permits it to be removed from the mandrel stamp.
• the elastomer 8 or spring arrangement stretches and pushes the mandrel upwards and detaches the stamped ring blank 2 form the lower stamp 6.
• the centre 1 is attached to it by pressing it into the hole of the ring 2 using a hand press, when it will become attached to the ring by a wedged joint, with the aid of the compressive forces created.
• a simplified description is that the manufacture of the coin takes place in such a way that a centre 1, with a precisely defined diameter dimension, is made from a brittle materials.
• a ring blank is made and is pressed to a defined dimension in such a way that the hole is given a precisely dimensioned conical shape.
• the centre 1 is pressed into the ring 2, when it is attached in place by the friction forces of the wedged joint and by the compressive effect caused by the flexibility of the ring.
• the mandrel using is shaping the ring can be attached to a dual-action cylinder.
• the upward movement of the cylinder will place the mandrel against the upper stamp during stamping and the return movement will pull the mandrel out of the hole of the ring.
• the mandrel is pulled after stamping to the lower dead point, when the stamped ring will also detach reliably from the mandrel.
• This solution is, however, more expensive to implement than a simple elastomer piece.

Landscapes

• Adornments (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=36539916

Family Applications (1)

Country Status (2)

Citations (3)

• 2006
  • 2006-05-12 FI FI20060471A patent/FI118508B/fi not_active IP Right Cessation
• 2007
  • 2007-05-07 EP EP07397013A patent/EP1854372A1/en not_active Withdrawn

Patent Citations (3)

Also Published As

Similar Documents

Legal Events