EP0023965B2 - Coin tester for coins of varying diameters - Google Patents

Abstract

The coins (8) are thrown into a common coin channel and affect the field of a coil (2; 52). The coil core consists either of several U- or E-cores (54, 55) arranged at right angles to the coin travel direction (5) in direct or spaced-apart adjacency, or of an oblong core (3) U- or E-shaped in cross section which lies at right angles to the coin travel direction. The spacing of the two outermost cores (54, 55) and/or the length of the core (3) is dimensioned to be of such a size that the coins (8) of varying diameter affect the coil field differently. The circuit for determining the effect on the field can comprise, for example, an alternator supplying the coil (2; 52) and a further coil (7; 53) coupled to the coil and connected to a comparison circuit. By means of the coil checker according to the invention it is possible to reliably test and determine even coins having greatly varying diameters.

Description

The invention relates to coin validators for coins of different diameters according to the preamble of claim 1.

A coin validator of this type is known from FR-A 2212589. It has two elongated coils that run transversely to the direction of the coin, each with a core arrangement consisting of a series of E cores glued together on the side. The E-core rows are arranged in a holder transverse to the direction of the coin and the core legs are perpendicular to the direction of the coin. A second coil is arranged after the first coils in the direction of coin movement. It is an air coil with a winding around the coin channel. A circuit evaluates the influencing of the coil field to determine the coin diameter caused by the coins passing through the first coils, which is approximately proportional to the coin diameter, and the influencing of the field of the second coil to determine the coin alloy.

The coil of the known coin validator intended for the determination of the coin diameter has a homogeneous coil field which is influenced by all acceptable coin sizes and all unacceptable coin-shaped bodies, the diameter of which lies between those of the smallest and largest acceptable coin sizes, depending on the diameter. The measuring range, which must be recorded when evaluating the influence on the coil field, includes sub-areas that are insignificant for coin testing, namely the sub-areas in which coin-shaped bodies whose diameters lie between widely differing diameters of acceptable coin sizes influence the field to different extents. The extent to which the coil field is influenced differently by an acceptable coin with a certain diameter and a coin-shaped body with a slightly different diameter is therefore relatively small in relation to the entire measuring range. Coin-shaped bodies whose diameters differ only slightly from the diameters of acceptable coins are therefore difficult to distinguish from the latter.

The invention specified in claim 1 solves the problem of developing the coin validator according to the preamble of this claim in such a way that the acceptable coins with different diameters are detected very reliably and just as reliably from one another and from unacceptable coins, especially those with acceptable ones only slightly different diameters can be distinguished.

• Fig. 1 das Blockschaltbild eines Münzprüferschaltungsteils mit zwei gekoppelten Spulen für die Durchmesserprüfung,
• Fig. 2 eine perspektivische Ansicht einer Anordnung der gekoppelten Spulen des Schaltungsteils nach Fig. 1,
• Fig. 3 einen Schnitt längs eines Teils des Münzeinwurfkanals eines Münzprüfers (Schnitt nach der Linie 111-111 in Fig. 4),
• Fig.4 einen Schnitt nach der Linie IV-IV in Fig. 3, und
• Fig. eine Fig. entsprechende, perspektivische Ansicht einer Anordnung von U-Kernen der gekoppelten Spulen unter Vernachlässigung der Abstände zwischen den U-Kernen.

Exemplary embodiments of the invention are described in more detail below with reference to the drawing. Show it:

• 1 is a block diagram of a coin validator circuit part with two coupled coils for diameter testing,
• 2 is a perspective view of an arrangement of the coupled coils of the circuit part of FIG. 1,
• 3 shows a section along part of the coin insertion channel of a coin validator (section along the line 111-111 in FIG. 4),
• 4 shows a section along the line IV-IV in Fig. 3, and
• A perspective view of an arrangement of U-cores of the coupled coils neglecting the distances between the U-cores.

In the coin checking arrangements shown, the coins to be checked of different diameters are thrown into a common coin insertion channel (not shown) which leads through the field of a coil 2 arranged on one broad side thereof and connected to the output of an alternator 1. The alternating current frequency of generator 1 is 100 kHz. The coil 2 has a core arrangement consisting of juxtaposed E-cores 3, its winding is wound on the middle leg 4 of the E-cores 3. The length of the core arrangement is approximately equal to the diameter of the largest acceptable coin type and is a multiple of the dimension of the core arrangement in the coin running direction indicated by an arrow 5 in FIG. 2. On the broad side of the coin channel opposite the coil 2 there is a coil 7 of exactly the same structure, that is to say also provided with a core arrangement comprising a plurality of E-cores 6 arranged next to one another. The legs of this core arrangement lie with the legs of the first core arrangement in three identical planes running perpendicular to the coin running direction 5, so that the best possible inductive coupling of the coils is achieved. The coupling is influenced by the coins that fall through the coin channel running between the coils 2, 7.

In the drawing, a medium-sized coin 8 is shown as it passes through the coils 2.

The coil 7 is connected to the input of a rectifier 9, the output of which is connected to a smoothing element 10. The smoothing element output is connected to the one inputs of six comparators 11 to 16, the other inputs of which are each connected to a voltage source via a potentiometer 21 to 26. The outputs of the comparators 11 to 16 are connected in pairs to bistable flip-flops 27 to 29, namely the comparators 11, 13 and 15 to the C inputs and the comparators 12, 14 and 16 to the R inputs of the flip-flops. A control part (not shown) which controls the coin collecting device is with the Q outputs of the tilting members 27 to 29 and one (not shown) in the coin running direction 5 connected to the coils 2, 7 arranged continuous signal transmitter.

The coin validator circuit part shown in FIG. 1 is designed for checking and determining coins with three different diameters. When a coin 8 to be checked arrives in the field of coil 2, the inductive coupling between coils 2 and 7 and thus the generator signal supplied to rectifier 9 are reduced. The smoothed DC voltage signal at the output of the smoothing element 10 thus becomes smaller when a coin is passed. It reaches a minimum if the coin 8 has a maximum influence on the coil field - as shown in FIG. 2 - that is, if the center of the coin lies between the middle legs of the cores 3, 6 and the coin with its entire diameter the field between the middle Thighs affected. The signal then rises again and returns to its original value after passing through the coin.

The larger the coin, the smaller the signal minimum, of course, and it is quite exactly inversely proportional to the coin diameter, because this is decisive for influencing the essential part of the field between the middle legs of the cores 3, 6.

The comparators 11 to 16 compare the output signal of the smoothing element 10 with the voltage supplied by the respective potentiometer 21 and 26. The potentiometers 21 to 26 define an allowable voltage range for the minimum output signal of the smoothing element 10 for each of the three acceptable coin types. The potentiometer 21 provides e.g. a voltage which is greater by a tolerance than the minimum output voltage of the smoothing member 10 when passing through the smallest acceptable coin type, the potentiometer 22 supplies a voltage which is less by a tolerance. Correspondingly, the potentiometers 23, 24 and 25, 26 deliver voltages which are larger or smaller by a tolerance than the output voltage of the smoothing element 10 in the middle and the largest coin type. The comparators 11 to 16 then supply a signal (value 1) when the output voltage of the smoothing element 10 is less than the output voltage of the respective potentiometer 21 to 26.

With an acceptable coin of the smallest type, the output voltage of the smoothing element 10 drops below the voltage value supplied by the potentiometer 21 and the comparator 11 sets the flip-flop 27, i. H. it forces the value 1 at the associated Q output. The (not shown) continuous signal generator switches on the (not shown) control part when the coin passes through, which triggers the acceptance of the coin due to the value 1 at the Q output of the link 27 and transmits the associated smallest coin value to the arithmetic unit of the coin collecting device. The control part then actuates a (not shown) resetting device which resets all the tilting members 27 to 29 to the 0 state. With an acceptable coin of the medium-sized coin type, the output voltage of the smoothing member 10 drops to a value between the voltage values of the potentiometers 23 and 24. The comparators 11, 12 and 13 deliver signals to the flip-flops 27 and 28 one after the other. The flip-flop 27 is set to state 1 by the comparator 11 and reset to state 0 by the comparator 12, whereupon the comparator 13 switches the flip-flop 28 to State 1 sets. The element 28 remains in this state, because the minimum of the output voltage supplied by the smoothing element 10 lies above the voltage value supplied by the potentiometer 24, that is to say the comparator 14 does not reset the flip-flop 28. In the subsequent query, the control part determines the state 1 of the link 28 and the reset device restores the reset state on the link 28. In the case of an acceptable coin of the largest coin type, the flip-flops 27 and 28 are first set to state 1 in succession and then reset to state 0. The flip-flop 29 is then set to state 1, queried by the control part and reset again.

In the case of an unacceptable coin with a diameter that deviates from the acceptable coins, the output voltage of the smoothing member 10 drops to a range that is not within the permissible range, that is to say, for example, between the values supplied by the potentiometers 22 and 23. When the voltage drops, the initially set rocker member 27 is reset, while the rocker member 28 is not set. None of the flip-flops is therefore in state 1 when the control part is queried, which indicates the unacceptability of the coin.

In the above embodiment, it was assumed that the coins consist of non-magnetic material. With coins made of magnetic material, the coupling of the coils 2 and 7 would increase with the diameter of the coins. However, the circuitry for testing magnetic coins could basically be the same as described above.

It was also assumed that the coupling only depends on the coin diameter and not, or at most negligibly, on the coin alloy. With the alternating current frequency of 100 kHz supplied by generator 1, this is in fact guaranteed for practically all alloys.

A test of the coin diameter that is completely independent of the alloy properties is particularly expedient if an alloy test is also carried out using a separate test coil (see the coils 48, 50 described below in FIGS. 3 and 4). Otherwise, of course, a lower AC frequency can also be selected, in which the diameter and alloy influence the coupling. (It is a prerequisite, of course, that the alloy differences are not exactly due to the difference in the coin Compensate the knife-related change in the coupling.) For the sake of completeness, it should also be mentioned that the coupling naturally also depends on the thickness of the coins, so that coins of larger diameter, because of their generally larger thickness, influence the coil field somewhat more than solely because of their Diameter would be expected.

3 and 4 are - as in the embodiment described above - two coupling coils 31, 32 opposite each other. The core of the coil 31 consists of eight E-cores 34 to 41, which are arranged at different distances next to one another in a cross-sectionally U-shaped holder 42 which is transverse to the direction of coin 33, so that their legs are perpendicular to the direction of coin 33. The dimension of the e-cores 34 to 41 in the direction of the coin 33 is a quarter of the distance between the surfaces of the two outermost cores 34 and 41 facing away from one another. The coil winding 43 encloses the middle legs of the e-cores 34 to 41. The coil 32 also has accordingly eight E-cores 44, which lie exactly symmetrically opposite the cores 34 to 41 on the coin channel 30.

One coin 45, 46, 47 of the three different sized coin types to be checked is shown in the coin channel 30. The arrangement of the cores 34 to 41 and the holder 42 is selected such that, on the one hand, unacceptable coins, the diameter of which differ only slightly from those of the acceptable coin types, influence the coil field as differently as possible from the acceptable coins, and on the other hand the influence on the coil field is approximately proportional to the diameter of the acceptable coins. The first condition is met in that the three coins 45, 46, 47 rolling on the narrow wall of the coin channel 30 on the left in FIG. 4 each cover one core on the right-hand side when passing through the coil 31, namely the core 36, 38 or 40, but do not influence the field of the core 37, 39 or 41 immediately adjacent to it. An unacceptable coin with a slightly different diameter either no longer covers the core 36, 38 or 40 or the core 37, 39, 41, which leads to a change in the coupling and thus the output signal of the smoothing element that is greater than that tolerance set for the acceptable coin potentiometers. When passing through the coil 31, the coin 45 covers the three cores 34 to 36, the coin 46 the five cores 34 to 38 and the coin 47 the seven cores 34 to 40. Because the diameters of the three coins are roughly the same as the number of cores covered by the coins, the second condition is also met.

The coin validator also has an alloy test circuit (not shown in detail) with two coupling coils 48, 50 arranged at a distance from the coils 31, 32 and having the same pot cores 49, 51. The outer diameter of the pot core 49 and 51 is smaller than the diameter of the smallest acceptable one Coin, which enables an alloy test independent of the coin diameter. (The circuit can be constructed similarly to that in FIG. 1, with the alternating current frequency of the generator 1 being chosen to be such that the influence of the alloy on the coil field is maximized.)

In the variant of two coupled coils 52, 53 for diameter testing shown in FIG. 5, each of the two winding core arrangements consists of seven U-cores arranged in a holder (not shown), of which the outermost ones with 54, 55 and 56 in the drawing , 57 are designated. The distances according to the invention are not apparent from this illustration. The coil windings enclose the webs of the U-cores arranged side by side. Like the coils 2 and 7, the two coils 52, 53 are arranged opposite one another on the coin channel, the legs of the U-cores 54 to 57 lying in two planes running perpendicular to the direction of coin movement.

In the exemplary embodiments described above, two coupled coils are always provided in accordance with the circuit principle chosen for FIG. 1, which are opposite one another on the coin channel. Of course, however, only one coil could also be provided, which, as a self-induction coil, belongs, for example, to an oscillating circuit fed by an AC power source. The damping (or, in the case of magnetic coins, the amplification) of the vibrations which occurs when a coin passes the field of the self-induction coil would then be a measure of the coin diameter (or of the alloy in the case of the coil 48).

Claims (7)

1. A coin checker for coins of different diameters having an elongate coil (2; 31) extending transversely to the direction of motion of the coin and a circuit (9-29) which evaluates the influence, brought about by the coins (8, 45-47) passing through the coil (2; 31), and approximately proportional to the coin diameter, on the coil field so as to determine the diameter of the coin, as well as a coil core arrangement which is composed of seveal E-cores (3; 34-41) the limbs of which stand perpendicularly to the direction of motion (33) of the coin, and a holder (42) which receives the E-cores (3; 34-41) and in which these cores (3; 34-41) are arranged side-by-side in a row extending transversely to the direction of motion (33) of the coin, characterised in that associated with each acceptable coin size (46) are two of the E-cores (38, 39) which are arranged with slight mutual spacing, but at a lager spacing from the remaining neighbouring E-core pairs (34/35, 36/37, 40/41) respectively associated with other coin sizes, in such a way that the acceptable coin size (46) respectively masks the one E-core (38) of the respective E-core pair (38/39), but does not influence the field of the other E-core (39) of the E-core pair (38/39), whereas a non-acceptable coin (45, 47) of slightly differing diameter influences either the fields of both E-cores (38, 39) of the E-core pair (38/39) (larger diameter) or of none of the two fields of the E-core pair (38/39) (smaller diameter).

2. A coin checker according to claim 1, in which the E-cores (3; 34-41) are replaced by U-cores (54,55).

3. A coin checker according to claim 1 or 2, characterised in that the coil winding (43) encircles the central limbs of the E-cores (3; 34-41) or, respectively, the cross-pieces of the U-cores (54, 55).

4. A coin checker according to one of claims 1 to 3, characterised in that the dimension of the cores (3; 34-41; 54, 55) in the direction of motion (5; 33) of the coin is only a quarter of the spacing of the mutually averted surfaces of the two outermost cores (3; 34,41; 45,55; 56,57).

5. A coin checker according to one of claims 1 to 4, in which the coil (2; 31; 52) is one of two coupling coils (2, 7; 31, 32; 52, 53) lying opposite one another at the coin channel (30), characterised in that the core arrangements of the two coupling coils are identicially constructed and are arranged symmetrically to the coin channel.

6. A coin checker according to claim 1, characterised by a second coil (48), the core (49) of which is smaller than the diameter of the smallest acceptable coil (45), both in the direction of motion (33) of the coin and transversely thereto, in order to make possible an alloy check which is independent of the coin diameter.

7. A coin checker according to one of claims 1, 2 or 6, characterised in that the external dimension of the E- or respectively U-cores (3; 34-41; 54-57) in the direction of motion (5; 33) of the coin is a fraction of the diameter of the largest acceptable type of coin.

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