A coin is typically made up of a slab-shaped, mostly round piece of metal, compris- ing an embossed surface with a number consisting of one or more separate figures which indicate the value of the coin. In addition, the surface of the coin may com- prise embossed letters, words, other marks or ornamental patterns. Coins are, first of all, used as official money and also as token coins intended for certain limited use, such as parking meters, for example, or other similar automatic paying machines.

In addition to said embossed coins, coins with holes are known. Dulling times of economic depression, coins were used which had a hole in the middle to save pre- cious metal. Furthermore, perforated token coins are known, intended to be used as media of exchange in slot machines, such as parking meters. Publication print FI- 43794 describes a set of tokens, the tokens of different value of the set containing holes of different shapes, placed in various ways, an identification device distin- guishing the unequal coins from one another on the basis of the holes. Patent publi- cation US-2836911 discloses a token provided with an eccentric opening which im- pedes the rolling of the coin.

The purpose of the invention is to provide a coin which is perforated in a manner known per se from before but in which the opening or openings of the coin differ from previous coins in that new goals are achieved with the aid of the openings. The coin according to the invention is characterised in being provided with one or more openings so that the opening or openings form a number that indicates the value of the coin.

In the coin according to the invention, the opening or openings serve an informative purpose, indicating the value of the coin, while also providing savings in raw mate- rial and decreasing the weight of the coin. The opening or openings provide the vis- ual indication of value of the coin which otherwise would have had to be included in the coin in the form of an embossed number. Simultaneously, the openings can naturally also be used for automatic identification of the coins. The indication of value of the coin in the form of the opening or openings is also easy to identify by touch; therefore, it fulfils the needs of the visually disabled better than the conven- tional coins.

The coin according to the invention which can be manufactured by casting or moulding and the opening or openings of which can possibly be made by die cutting from metal is well-adapted to both official money for common use and to tokens for various limited purposes.

Regarding the indications of value of the coins, nwnbers 0, 1, 2, 3, 4, 5, and 7 can be considered as well as numbers made up by combining them; in practice, only numbers 0, 1, 2, and 5 can be sufficient. Regarding these numbers, zero is the easi- est to visualise with the aid of two curved openings located against one another, while one single opening is enough to indicate the other said numbers. When a number with two or more figures, such as 10, 25 or 100, is indicating the value of the coin, two or more openings are naturally needed.

In addition to a single coin, a special object of the invention is a set of coins consist- ing of two or more different coins that correspond to the above description. Accord- ing to the invention, a set can be provided which is comprised of coins of different values in which the numbers corresponding to the value of the coins can typically be selected, for example, from the following: 1, 2, 5, 10, 20, 25, 50, 75, 100, 200, 250, 500, and 1000.

The invention is illustrated with the aid of examples and with reference to the ap- pending drawing in which: Fig. 1 shows a coin according to the invention with openings die cut to provide an indication of value comprising a two-figure number (20), Fig. 2 is section II-II of Fig. l, Figs. 3 and 4 show coins according to the invention provided with a one-figure indi- cation of value (1 and 5), and Fig. 5 shows a coin according to the invention, provided with a three-figure indica- tion of value (100).

Coin 1 according to Figs. 1 and 2 is a discoid round piece of metal which is manu- factured of raw metal material by casting, having number 20 that constitutes an in- dication of value formed therein. This two-figure number consists of three parallel openings 2, 2', 2", the first opening alone forming a number 2 and the next two numbers, which are arranged opposite one another to provide a ring, together form a zero. According to Fig. 2, edges 3 of each opening 2, 2', 2" are rounded to avoid sharp edges. Periphery 4 of the coin is shaped in a conventional way to be slightly thicker than the rest of the coin to avoid the wearing of markings possibly formed inside the edge of the coin.

Figs. 3 to 5 show three other coins 1', 1", 1" according to the invention, the sizes and indications of value of the coins differing from coin 1 of Fig. 1. In Fig. 3, the indication of value of coin 1' is provided by opening 2"' which corresponds to number 1; the indication of value of coin 1" of Fig. 4 is provided by opening 2"" which corresponds to number 5 and, in coin 1"' of Fig. 5, the indication of value is provided by five parallel openings 2"', 2', 2", 2', 2", the first of which corre- sponding to number 1 and the next openings forming, in pairs, the pair of numbers 00 so that the number indication the value of the coin is 100.

The coins according to Figs. 3, 4, 1, and 5 together form an example of the set of coins according to the invention, the values of the unequal coins of the set being indicated with figures 1, 5, 20, and 100. The set contains examples of one-, two- or three-figure values of the coin and also of coins where the number of openings is one, three or five. Furthermore, the set contains examples of figures 0, 1, 2, and 5 which can be used to form the most ordinary numbers that can be considered as val- ues of the coin. When completed into a practical set of coins, the set according to the Figures would most likely also contain coins with indications of value of 10 and 50, and possibly also coins of higher values, such as 200 and 500. However, the values of the set can be chosen freely within the invention, according to the respec- tive needs.

It is clear to those skilled in the art that the applications of the invention are not limited to the examples presented above but can vary within the appended claims.

The outer appearance of the coins in particular and the letters, words, and patterns possibly included in them can vary extensively, the appended drawings only pre- senting the principle of the invention in its simplest form. The manufacture of the coins can also be implemented in various ways: the coin with its openings can be formed in one mould casting or the openings can be die cut separately after the casting.