Tester For Different Types Of Coins

Abstract

A method and apparatus for checking coins during their travel along at least one coin channel of a coin checking device is disclosed which contemplates subjecting each coin to a damping measurement to obtain a first type of information about the coin, and also subjecting the coin to at least a second measuring operation to obtain a second type of information about the coin being checked. The invention further teaches the possibility of performing a still further damping measurement to obtain additional information about the coin different from said first type of information.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a new and improved method for checking coins moving along at least one guide channel of a coin checking apparatus, and further pertains to a new and improved coin checking apparatus for carrying out the aforesaid inventive method.

The previously known techniques for checking coins almost exclusively rely upon mechanical apparatuses. These mechanical apparatuses check the thickness, diameter and weight of the coins. However, such coin checking apparatuses can be easily fooled by metal discs or washers, provided that such approximately possess the dimensions of the actual coins and provided further that their weight corresponds to the weight of the real coins which, if necessary, can be corrected by boring the metal discs or washers or by adding heavier metals thereto.

Apart from these mechanical techniques there have also become known to the art electronic techniques for checking coins, so called "damping-measuring techniques". All of these so-called "damping-measuring techniques" manifest themselves by virtue of their relatively low price and extremely practical measurement results. The decisive drawback of this coin checking method, however, resides in the fact that they can be even more easily fooled by counterfeit coins than the mechanically operating equipment. This can be explained when it is realized that for all damping measuring techniques, as a practical matter only one composite value can be measured, resulting from the sum of those parameters of the coin which influence the measuring operation, such as material, thickness, diameter. The composite value of a coin, such as for instance the German one-mark piece, stamped from a metallic alloy possessing only average electrical dampening qualities, can be very easily obtained by a smaller and thinner coin formed of a more pronounced damping metal, copper for instance.

SUMMARY OF THE INVENTION

Accordingly, there is a real need in the art for coin checking equipment and techniques which are not associated with the aforementioned drawbacks of the prior art. Therefore, a primary objective of the present invention is to provide just such improved coin checking technique and equipment therefor which overcomes the aforementioned disadvantages of the prior art and which capably fulfils this need.

Another, more specific object of the present invention relates to an improved method for checking coins which, on the one hand, insures for sufficiently positive checking results and, on the other hand, permits undertaking the coin checking operation in an economical, feasible and reliable fashion.

Still a further significant objective of this invention relates to an improved coin checking technique and equipment therefor which is extremely reliable in operation, has great versatility insofar as it is readily capable of checking coins of different denominations and types with utmost integrity, and effectively safeguards against the improper use of false or counterfeit coins or coin types.

Now, in order to implement these and still further objects of the present invention, which will become more readily apparent as the description proceeds, the inventive method is manifested by the features that each coin to be checked is subjected to a damping measurement, and by means of at least a second measurement operation there is determined either the diameter and/or the thickness and/or the existence of a central bore and/or the embossing of the coins, or by means of a second damping measurement operation, which however functions according to a different viewpoint, there is once more derived a composite measurement value based upon other parameters.

Such type coin checking equipment has not yet become known to the art. As already explained heretofore, when utilizing a coin material possessing a more pronounced damping characteristic it is possible to attain the damping value of a certain coin in that certain modifications are undertaken at the geometric dimensions of the counterfeit coin. This can be achieved with respect to thickness, diameter and also by boring a hole in the counterfeit coin.

With all of these attempts to outwit a damping measurement apparatus with the aid of such type prepared metallic discs or washers, the manipulations with respect to diameter and the central bore have the greatest practical significance. Therefore, hereinafter no particular attention will be paid with regard to thickness measurements, because such can be neglected with the view of realizing advantageous manufacturing costs of the inventive apparatus. Yet, it is here mentioned that the observations undertaken hereinafter with respect to a measurement apparatus for the determination of the diameter and/or the provision of a bore or hole at a coin, can be analogously applied for apparatus for the determination of the existing thickness.

Now the invention, first of all, contemplates that initially an apparatus, which will be hereinafter described in greater detail, determines the geometric criteria of a coin, and thereafter frees a current path at which only the correct damping value derived with respect to the determined geometric criteria generates a signal which can then be further conducted for the evaluation process. In other words: a signal can only appear if, for instance, the first mechanism has responded such as to indicate that the measured coin possesses the size of, for instance, a German 1-mark piece, and if the subsequent, second measuring location has determined by means of a damping measurement that the coin to be checked has provided just that damping measurement value which corresponds to a German 1-mark piece. In such case it is assumed that the checked coin was a true German 1-mark piece.

Thus, any possibility of achieving a deceptive intent through use of larger or smaller coins has been thwarted. Indeed, for instance, it is possible to achieve with a small copper coin the damping value of a German 1-mark piece. Yet, in such case the evaluation of such ostensibly correct damping value will be suppressed, because the previously connected arrangement for the determination of the diameter has ascertained that the coin does not possess the correct diameter dimension of a 1-mark piece. The diameter checking mechanism would more likely have freed the current path which has corresponded to the diameter of a smaller coin and the therewith associated damping value.

Through the inventive combination of an apparatus for the determination of the diameter and/or thickness and/or bore provided at the coin with a damping measurement mechanism, it is possible for instance, to check in a single coin channel a number of coins of different damping values without there simultaneously occurring overlapping of smaller or larger coins or counterfeit coins.

It is completely immaterial for the performance of the inventive method whether, for the determination of the geometric criteria of the coins to be checked, there are employed contacts or whether the measurement operation proceeds in a contactless fashion.

In accordance with a number of inventive concepts the method can be carried out in different ways. For instance, it is possible to utilize mechanical contacts and to derive the force necessary for their actuation from manual manipulations which are available during insertion of the coin into the coin slot.

According to a further aspect of the invention, it is also possible to operate mechanical contact devices in such a way that there are used for the continuous movement of the coins to be checked a motor-derived force. According to a further concept of the invention it is possible to undertake the measurement of the geometric criteria through the utilization of a contactless measuring technique.

Moreover, the method aspects of the invention can furthermore be manifested by the features that the evaluation of the measurement signal can occur in a digital or analogue fashion. Moreover, in the case of a digital evaluation of the signal it is possible to undertake the evaluation process, through appropriate application of the measuring head and the design of the circuitry, by means of a so-called "sequential circuit" or also by means of a so-called "selective pair-circuit." Both of these exemplary embodiments will be more fully described hereinafter during the discussion of the inventive apparatus manifestations for carrying out the inventive coin checking technique.

Additionally, it is here to be understood that as far as the inventive method is concerned it is completely immaterial whether initially there is determined the geometric criteria of the coins and then there is undertaken the damping measurement operation, or whether these procedures are performed in the reverse sequence.

Additionally, it is here mentioned that because of the differences of the individual coins it is possible to design and construct the apparatus for the performance of such inventive method in different ways.

Thus, initially one must differentiate between coin checking apparatuses for only one coin and those which are capable of checking a plurality of coins. In the case of the last-mentioned group, it is necessary to differentiate between multiple-type coin checking devices in which there is available for each coin type an individual coin inlet slot (in other words for each coin checking device a group of coin inlet or receiving slots), or those coin checking devices for a number of coins in which all coins, without differentiation, are introduced to only a single coin infeed slot.

Within the confines of the inventive concepts of measuring individual parameters of a coin and utilizing the result of this measurement operation for amplifying an indirectly operating measuring technique which determines a number of parameters in the form of a composite value, there is also contemplated the determination of the embossment or stamping of the coin.

As previously mentioned it is possible for non-embossed metallic discs or washers to simulate the presence of a coin, because they coincidently generate the same damping value or "composite value". Therefore, it is an objective of the invention to make it more difficult or impossible to use this simple and obvious possibility for outwitting an electronic coin checking device. Therefore, the invention proposes the use of an optional measurement arrangement in order to safeguard the damping measurement operation and such then determines whether the coins to be checked are provided at their surfaces with recesses. A common characteristic of such measurement arrangements is, likewise according to the inventive aspects, that they store their Yes/No-response which is then evaluated upon the completion of the travel of the coin through a measurement path. Particular considerations with respect to the construction thereof are not necessary, because for such there is applicable in principle the same considerations which previously were made with respect to the arrangements for the determination of the diameter or thickness or bore and such, for instance, can be achieved by scanning the coin's surface by means of a piezoelectrical element in known manner.

Accordingly, it is a further objective of the invention to provide a coin checking apparatus for the performance of the inventive method, wherein the checking of a number of coin types is undertaken by means of a damping measurement and an evaluation circuit which is manifested by the features that only individual components of the measuring-and evaluation circuit are only repeatedly provided in accordance with the number of coin types to be checked, and at least one so-called sequence-circuit, consisting of the circuitry of the coin collecting device and a resetting circuit for the momentarily employed circuit components, is provided only one time and used for the checking of all coin types.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 is a fragmentary longitudinal sectional view taken through a coin checking mechanism for a coin type in which the contact testing for the diameter of the coin is arranged directly at the coin infeed slot at the front plate of the coin checking device;

FIG. 2 is a fragmentary longitudinal sectional view through a single-type coin checking device wherein the relevant contact is arranged in the channel for the travelling coins and therefore is protected against being tampered with;

FIG. 3 is a fragmentary longitudinal sectional view through a single-type checking device in which the relevant contact is arranged in the same manner as in FIG. 2 above, however possesses such a long contact lever portion that the range of pivoting of such contact lever falls within the measuring arrangement for the damping measurement;

FIG. 4 schematically illustrates the rear face of a coin checking apparatus for four different coins, in which four separate coin infeed slots for each coin type open into a common checking channel;

FIGS. 5 to 9 illustrate multiple-type coin checking equipment utilizing a common coin infeed slot for all coin sizes and types which are to be checked, and specifically wherein,

FIG. 5 schematically depicts the rear face of a coin infeed slot having mounted thereat a slide member and four contact arrangements corresponding to the four different size coins to be deposited,

FIG. 6 is a fragmentary longitudinal sectional view through a coin checking channel for four different size coins in which four testing or scanning elements for the individual size coins are arranged after one another, to provide the so-called "sequential circuit",

FIG. 7 is a fragmentary longitudinal sectional view through a coin checking channel in which four measuring probes are arranged for determing the coin diameter and a further measuring probe is arranged for determing the existence of a bore or hole at the coin in a particular manner, and defining the so-called "selective pair-circuit",

FIG. 8 is a cross-sectional view through a motor-driven conveying or feed disc arrangement for the coins with the associated slide member for the determination of the diameter of the coins and for pressing the coins so as to assume a specific measuring position, and

FIG. 9 schematically illustrates a motor-driven conveying disc for the coins which is constructed in stepwise fashion according to the principle of the caliper gauge, and wherein an entrained sliding contact bridges signal conductors as a function of the diameter of the entrained coins, these signal conductors evaluating the diameters of the associated damping measurement values;

FIGS. 10 to 23 inclusive illustrate different possible arrangements for the measuring probes and provide appropriate clarifying explanations with respect thereof;

FIGS. 24 to 26 illustrate respective block circuit diagrams according to which a coin signal can be delivered to a plurality of voltage discriminators (so-called threshold value circuits); and

FIGS. 27 to 29 illustrate respective block circuit diagrams by means of which the signals of a number of coins can be delivered to a single threshold value circuit for evaluation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Describing now the drawings, the exemplary illustrated embodiments of coin checking devices illustrated in FIGS. 1 to 3, each embody a front plate member 10 provided thereat with the coin infeed slot 11 and a coin channel 14 formed of the base member 12 and the cover member 13. Within each coin channel 14 there has been shown a respective throughpassing coin 15 traveling in the direction of a measuring probe 16 arranged within the associated coin channel 14. The aforedescribed structure will be understood to be common to all three embodiments of coin checking devices depicted in FIGS. 1, 2 and 3 respectively.

Now, turning specifically to the arrangement of FIG. 1, it will be understood that a microswitch 17 is arranged behind a protective cover plate 18. Microswitch 17 is directly attached to the front plate 10 in such a way that its actuation plunger 19 extends slightly into the area of the coin infeed slot 11 as shown. When it is attempted to insert a coin into the coin traveling channel 14, then, the actuation plunger 19 of the microswitch 17 must be actuated if such coin possesses a predetermined minimum size. Coins possessing too small dimension will not be able to actuate the plunger 19 of the microswitch 17, and therefore will not be able to close the current path for the evaluation of a signal delivered by the measuring probe 16. Coins which possess a sufficient size to actuate the microswitch 17 are only insignificantly smaller than the correct coins intended to be collected and for which the coin infeed slot 11 has been exactly designed. Coins possessing too large a size can, indeed, under circumstances actuate the plunger 19 of the microswitch 17, but because of their oversize cannot be inserted into the coin chute or channel 14. It is here mentioned that placing of a current path into a preparatory state by means of the microswitch 17 can, according to a further concept of the invention, only be maintained for a momentary or temporary adjustable period of time. In this manner, it is possible to prevent that the preparatory state of a current path which may have been brought about through tampering or manipulations undertaken at the coin checking device by the user with the use of a too large size coin, will then not be maintained if subsequent thereto there is inserted a coin possessing too small a dimension.

However, it is here further indicated that the aforementioned drawback existent with the arrangement of FIG. 1 can be effectively prevented if the switch mechanism is completely removed from being tampered with by the user, which can be successfully achieved by arranging such within the confines of the coin channel or chute 14. Such an arrangement has been schematically depicted in FIG. 2. There, it will be observed that the microswitch 20 is located at the upper side 13 of the coin channel 14 so that its feeler lever member 21 extends into the region of the coin channel 14. Once again, the coin infeed slot 11 has been designed to limit the insertion of coins in accordance with prescribed size and thickness. Coins possessing a dimension smaller than that of acceptable coins will be indeed capable of moving through the coin chute 14 past the measuring probe 16, yet without previously actuating the microswitch 20. Actuation of the microswitch 20 can only then be undertaken by a coin possessing a sufficiently large size, and this operation is a prerequisite for the transmission of a possibly correct measurement response signal emanating from the measuring probe 16.

Now with the embodiments depicted and described with respect to FIGS. 1 and 2, it is necessary to bridge the time period from the moment of switching the microswitch until obtaining a measurement response signal from the measuring probe 16. This bridging effect can be easily achieved, for instance, through the provision of a self-holding relay which can again be de-energized by a suitable command delivered from the measuring probe 16 or else such can be undertaken by means of an adjustable timing element.

However, it is possible to save on the expenditure of additional components which are then required if there is used such a timing element or self-holding relay, if, according to a further aspect of the invention, the coin checking mechanism is designed in accordance with the teachings of FIG. 3. By now referring to the arrangement shown therein, it will be observed that the microswitch 20 is equipped with a feeler lever 22 which is so long that it extends into the operable region of the measuring probe 16. Furthermore, this FIG. 3 has depicted the coin 15 in coincidence with the measuring probe 16, in other words such coin has exactly reached the point of time at which the measuring probe 16 delivers a measurement response signal. The microswitch 20 has already been activated for a certain period of time and will further remain activated for an additional period of time after the measuring probe 16 has delivered its measurement result. By virtue of this circuit arrangement and design of the coin checking device, it is possible to dispense with the otherwise required expenditure of components such as timing elements or the like.

A further common feature of the various embodiments of coin checking devices depicted in FIGS. 1 to 3 resides in the fact that the installation is continuously furnished with power or current. However, situations are conceivable in which the operation of such an installation or installations is dependent upon battery power. In such case, an attempt would be made to maintain the consumption of current as small as possible. Hence, according to a further teaching of the invention, it is possible, in all of these cases, to utilize the microswitch also for the switching-in and switching-out of the current supply network. With the constructions of coin checking devices depicted in FIGS. 1 and 2 wherein there is of necessity required a timing element or the like, the latter can be used not only for switching the current path, but also for switching the current or voltage supply network. With the arrangement of FIG. 3, the microswitch 20 is advantageously constructed as a double-pole switch and undertakes, apart from switching the current path, also the switching of the voltage supply network.

FIG. 4 illustrates the rear face of a coin checking apparatus for four different coins. Hence, by referring to FIG. 4 more specifically, it will be observed that there are provided four adjacently arranged coin infeed slots 23, 24, 25 and 26 communicating with sheet metal guide members 27, 28, 29 and 30 respectively, for guiding the deposited coins into a common coin checking chute 31. Measuring probes 32 and 33 are arranged at both sides of this coin checking chute 31. The coin infeed slots 23, 24, 25 and 26 are designed in respect of the diameter and thickness of the permissable coins. Here also, the actuation plungers of respective microswitches 34, 35, 36 and 37 extend slightly into the upper region of the corresponding coin infeed slots 23, 24, 25 and 26. The amount with which the plungers extend into the corresponding coin infeed slots is determined in accordance with the permissable switching play of the plungers and in accordance with the deviations of the diameter of the coins towards their lower limit. What has been described with regard to the operation of the arrangement of FIG. 1 is equally applicable for the operation of this switching arrangement. Furthermore, a switching mechanism 38 is associated with the coin infeed slot 24, switching mechanism 38 possessing a plunger which scans the thickness of the inserted coins. Thus, when the switch mechanism 38 is not placed into operation, which would be the case if the deposited coins are too thin, then it prevents the evaluation of a signal derived from the measurement apparatus. Finally, it is here mentioned that as far as the arrangement of the microswitches are concerned, the same observations made with respect to FIG. 1 are equally applicable here.

FIG. 5 illustrates the rear side or face of a coin infeed slot for coins of different diameter. Once again, reference numeral 10 serves to designate the base or front plate whereas reference numeral 11 designates the coin infeed slot which, insofar as its dimensions are concerned, has been cut or otherwise designed with respect to the largest size coin and the thickest coin of the prescribed classification of four different coins. Furthermore, a substantially T-shaped slide member 39, possessing at its upper surface four stepped portions which correspond to the diameter differences of the relevant coin classification, moves in guide members 40 and 41 and is retained in its starting position by a pair of spring members 42 and 43.

Now a coin which is smaller than the smallest of the four acceptable coins, will pass through the coin infeed slot 11 without, however, displacing the slide member 39. The smallest coin of the acceptable coin classification will slightly raise the slide member 39 so that the plunger of the associated microswitch 44 will be actuated. The third largest coin of the coin classification will raise the slide member 39 through a slightly greater distance, so that apart from actuation of the plunger of the microswitch 44 also the plunger of the microswitch 45 will be activated. It therefore follows that upon insertion of the second largest size coin of the coin classification, the plungers of the microswitches 44, 45 and 46 will be energized or activated, and only the plunger of the remaining microswitch 47 is not activated. Finally, upon insertion of the largest size coin of the coin classification the slide member 39 will be raised to such an extent that all four plungers or switch contacts of the microswitches 44, 45, 46 and 47 will be actuated. Such actuation of different contacts can be utilized, in known fashion, to switch-in appropriate current paths.

In the embodiment of coin checking device depicted in FIG. 6, the front plate has again been designated by reference character 10 and the coin infeed slot formed thereat by reference character 11. Just as was the case with the arrangement of FIG. 1, here also the coin chute or channel 14 for the coins 15 is bounded by the lower wall member or base 12 and the upper wall member or cover 13. At the end of the coin chute 14, there is arranged a measuring probe 16 for performing a damping measurement operation, as for instance described in my copending U.S. Patent Application, Ser. No. 55,752 filed July 17, 1970, now U.S. Pat. No. 3,682,286, and entitled "Method for Electronically Checking Coins". Furthermore, between the coin infeed slot 11 and the measuring probe 16, there are arranged four further measuring probes 48, 49, 50 and 51, spaced at various distances, as shown, from the base 12 of the coin chute or channel 14. The measuring probes 48-51 represent, for instance, inductive feelers, which then assume a switched state if coins pass thereby at a certain minimum spacing. According to the teachings of the invention, the arrangement of such feelers 48, 49 50 and 51 is undertaken in such a manner that initially the switch for the largest coin is first arranged, and then in the following sequence the switches for the remaining smaller coins, providing what has been conveniently termed herein a so-called "sequential-circuit arrangement". Moreover, in this context, it is mentioned that it is advantageous to design the circuitry such that -- as indicated in the exemplary embodiment -- response of the probe 48 releases the current path intended to conduct the damping measurement signal of the largest coin of the coin classification and simultaneously insuring that energization of the probe 48 suppresses the excitation of the probes 49, 50 and 51. Operation of the smaller probes is to be undertaken in analogous fashion; that is to say, response of the probe 49 suppresses the response of the subsequent probes 50 and 51.

It is here mentioned that, according to a further aspect of the invention, the switch means cannot only be used for the determination of either the diameter of the coins or only the thickness thereof, but furthermore, it is possible to employ such switch means to advantage to also determine both the diameter and thickness of the coins. To this end, it is possible for instance, to incline the coin channel 14 also transverse to the direction of travel of the coins so that the coins, during their throughpassage, bear against a predetermined side surface of such channel. Additionally, there is then arranged probe members at the side of the channel facing away from the side against which the coins travel. Hence, between the coins and the probes there is thus formed a predetermined air gap which is dependent upon the thickness of the coins. If this spacing exceeds a predetermined value, then the probe cannot respond, indicating that in such case there is present a coin which is too thin. Through appropriate arrangement of the measuring probes it is possible to have coins which are too thick, prior to reaching the probe corresponding to their actual diameter, to energize another measuring probe, and therfore to simulate an incorrect diameter. It is here remarked that through the use of suitable light sensitive components, piezoelectrical components or electromechanical components or similar switching feeler members, it is possible to likewise realize the inventive concepts.

Now FIG. 7 illustrates the arrangement of a coin checking device utilizing light barrier means for determining the diameter of the coins as well as for determining the presence of bores or apertures at the coins. Once again, the same reference characters have been conveniently employed here to designate the corresponding components of the coin chute or channel which were used during the discussion of the arrangement of FIG. 6. Apart from the components in this arrangement, similar to those appearing in the arrangement of FIG. 6 as evidenced by the similar reference characters, there is also provided a light barrier means 52 which can only be actuated by the largest coin of the coin classification. Furthermore, reference characters 53, 54 and 55, 56 and 57, 58 represent, by way of example, pairs of light barrier means which can be used with particular advantage for the determination of the diameter of the coins, because they render superfluous extensive logical coupling. More specifically, then, each coin is associated with a pair of light barrier means, with the exception of the largest size coin with which there is only associated a single light barrier means 52. The light barrier means 54, 56 and 58 of each pair, closest to the bottom 12 of the coin chute 14, serves to energize a current path provided for the corresponding diameter of the coin being checked, whereas the light barrier means 53, 55 and 57 of each pair, and facing away from the bottom or base 12 of the chute means 14, serves to remove the preparatory switched state of each such current path.

The simplicity of this circuit arrangement will be immediately evident if there is assumed, for the moment, the throughpassage of a very large size coin. This coin will then initially energize the light barrier 52, and therefore will render possible that the subsequently arranged flip-flop or the like can undertake placing of the current path provided for the largest coin into a preparatory state. During further travel of this coin into the coin chute 14, such will then also excite or energize the light barrier means 54 and therefore also energize the subsequently arranged flip-flop associated therewith. Shortly thereafter, however, the light barrier means 53 will be energized which then extinguishes the preparatory state of the flip-flop of the subsequent light barrier means 54. The same occurs at the other pairs of light barrier means 56, 55 and 58, 57. Hence, of all of the four current paths which have been placed into a preparatory state, three of them have shortly thereafter again been extinguished, and only the original current path coupled with the light barrier means 52 has maintained its preparatory state for the measurement result derived from the measuring probe 16.

The exemplary embodiment of coin checking device depicted in FIG. 7 depicts the situation where the coin 15, because of its diameter, has just energized the light barrier means 56, but has not been able to remove this switching signal because its size is not sufficient to switch the light barrier means 55. The conductors of the light barrier means 52 and light barrier means 54 are not placed into a preparatory state because these light barrier means have not been actuated. The same considerations are therefore also applicable with regard to the light barrier pair 58/57. Hence, the coin 15 has thus, once again, only placed into a preparatory state one of four pulse conductors, there thus being provided a so-called "selective pair-circuit arrangement".

Continuing, it will be observed that a further light barrier means is designated at reference character 59. It serves to determine the presence of holes or bores at the coins. This light barrier means 59 is mounted at such a spacing from the base or bottom 12 of the coin traveling channel 14 that, in all probability, both holes of the smallest as well as the largest coins will fall into its operating zone. It is mentioned that at this location small holes are relatively insignificant for the outwitting of the described coin checking device. Furthermore, it is here stated that what will be described hereinafter with regard to a single light barrier means can be analogously attained if there are successively coupled two or three light barrier means in the event that a larger zone is to be monitored. The invention likewise contemplates that the light barrier means 59 actuates a switch which enables the evaluation of a so-called "correct" -signal. Actuation of the switch, according to the invention, should only then be possible if the light barrier means 59 has received a pulse. Such actuation should be extinguished in the event that instead of receiving one pulse, it receives two pulses. In order to achieve this switching function, the invention contemplates utilizing to particular advantage a bistable multivibrator (flip-flop). The mode of operation of this type circuitry should be apparent if it is considered that a coin without a hole, during its throughpassage, will only block the light of the light barrier means 59 once, therefore generating a single pulse which, in turn, will place the flip-flop into a definite switching state. On the other hand, a coin possessing a hole will firstly block the light of the light barrier means 59, yet when the hole passes the light barrier means the prior darkening effect is removed, and during further travel of the coin the passage of light at the light barrier means 59 is once again blocked. As a result, there are generated two pulses functioning in such a manner that the flip-flop is brought into its switching state and such shortly thereafter is again extinguished. Only if there appears a coin which is devoid of a hole will there thus be generated a signal which is stored and later used for evaluation of the coin, and which signal has appeared because of the presence of the correct diameter and the correct damping measurement value of the coin.

It should equally be apparent that upon reversing this principle of the light barrier means 59 it is also possible to determine the presence of holes or bores which should be present in the actual coins. In such case, by a reversal of the switching operation in known manner, there can be achieved that only coins of the correct diameter and possessing a hole and having a certain damping measurement value will be accepted as proper or correct coins, whereas coins without any hole will be rejected as false or improper coins.

FIG. 8 illustrates a modified version of coin checking device incorporating a base or front plate member 60 at which there has been machined a substantially circular-shaped recess, denoted by the line 61. The depth of the recess 61 corresponds approximately to the thickness of a coin. This circular-shaped recess 61 merges at its lower region with a shaft or chute member 62 which forks into the branched portions 63 and 64. Reference numerals 65 and 66 designate both positions which can be assumed by a directional switch means for proper and improper coins. A coin infeed channel 67a is formed between the channel walls 67 and 68 at approximately the same height as the circular-shaped recess 61. Reference character 69 designates a projection which extends into the circular-shaped recess 61, whereas reference numeral 70 denotes a conveying disc member for coins which is equipped with a notch 71. In the basic position of the equipment this notch 71 is situated opposite the coin infeed channel 67a bounded by the walls 67 and 68. The depth of the notch 71, defined by the circular arcs 72 and 73, corresponds to the diameter of the smallest coin of a coin classification or sort. The spacing between the circular arc 72 and the peripheral portion of the circular-shaped recess 61 corresponds to the diameter of the largest acceptable coin. It is here also mentioned that the coin infeed channel 67a between the walls 67 and 68 is likewise cut or designed to receive such largest acceptable coin size.

Continuing, it will be observed that there is also provided an inverted, substantially T-shaped slide member which moves against the force of a spring 77 between the supports 75 and 76. A protruding arm member 78 of the slide member 74, depending upon the position of such slide member, actuates one or the other of the contacts 79, 80, 81 and 82 as a function of the diameter of the coin which has moved such slide member 74.

A coin of optional diameter is placed through the coin infeed slot 67a and arrives at the zone of the notch 71. As a result of the insertion of the coin a non-illustrated motor serves to thereafter drive the conveying disc member 70 through one complete rotation and then such conveying disc member 70 is again brought to rest. Excitation of the drive motor can be undertaken by means of a non-illustrated switch arranged at the region of the coin infeed slot 67a. The conveying disc 70 for the coins, moving in counter-clockwise direction, serves to forwardly advance, by means of its edge portion 83, the inserted coin until such coin comes into coincidence with the measuring probe 16 and generates a signal.

Already prior to arrival of the coin at the region of the measuring probe 16, this coin as a function of its diameter, will have displaced the slide member 74 through a predetermined path in an upward direction, and therefore, will have actuated one of the four switches or contacts 79, 80, 81 and 82. Hence, in known manner it can be insured that only a damping measurement signal will be available for evaluation if such dampening measuring signal is in a certain desired relationship with a predetermined coin diameter. During further travel of the conveying disc member 70, the coin will move away from beneath the slide member 74 and enable such to return into its starting position. At such time as the revolving coin conveying disc 70 has reached its lower dead-center position of its circular path of travel, the coin within the notch 71 will now drop into the chute 62, and by virtue of the corresponding desired positioning of the switching lever, either into the full line position at 65 or the phantom line position at 66, such coin will be either collected because it is a correct coin or it will be rejected because it is a false or improper coin. The mechanics of actuating the directional lever 65/66 has not been explained in greater detail hereinafter since, such does not constitute a material aspect of the invention and furthermore any suitable actuation mechanism capable of selectively bringing such lever into one or the other of the illustrated positions can be readily employed. Finally, it is mentioned here that the substantially T-shaped slide member 77 further simultaneously ensures that the coin will be brought into a definite position with respect to the measuring probe 16.

FIG. 9 illustrates a modified version of coin checking equipment in which there is provided a base or front plate 84. Here also, a substantially circular-shaped recess, following the line indicated by reference character 85, is provided at such base plate 84. Circular-shaped recess 85 merges at its lower end with a channel 86 and at an inclination towards its upper end with a coin infeed channel 87 receiving the coins which are to be checked. A disc member 88 rotates within the circular-shaped recess 85, disc member 88 being provided with projections 89, 90 and 91 in the manner of a caliper gauge. The corresponding stepped portions of the projections 89, 90 and 91 are accommodated to the diameter of the coins which are to be accepted. Moreover, at the region of the projections 89, 90 and 91, this disc member 88 is equipped with a tongue-like extension or projection member 92 which follows the circular arc of such disc member.

Continuing, it will be understood that the reference character 16 designates a measuring probe arranged at the apex of the circular path of travel of the disc member 88, whereas reference numeral 93 indicates a coin which has been inserted. Just as was the case with the preceeding embodiment, here also a non-illustrated switch member, arranged at the region of the infeed channel 87, causes the disc member 88 to undertake one complete revolution through the agency of a non-illustrated motor, and upon completion of such revolution, this disc member is again brought to standstill. During rotation of the disc member 88, the sliding contact 94 having an elastic spring 95 likewise moves because it is secured to the disc member 88. Depending upon the size of the inserted coin, such will be eventually engaged by one of the projections 89, 90 or 91 and moved past the measuring probe 16. The very large size coin will reach the measuring probe 16 sooner than a very small coin. In the embodiment of FIG. 9, the spacing of the coin 93 from the measuring probe 16 has been indicated by the angle 96. At the same angular spacing from the measuring probe 16, as indicated by the reference numeral 97, and spaced from such measuring probe 16 in the direction of rotation of the disc member 88, there are arranged a pair of contacts 98 and 99 which can be bridged by the elastic spring or feeler member 95 of the sliding contact arrangement 94.

After the drive motor for the revolving disc 88 has been placed into operation, the coin 93 entrained thereby will be displaced upwards and eventually arrive in a position where it is in coincidence, that is to say, in overlapping position, with respect to the measuring probe 16. As a result, measuring probe 16 delivers a suitable signal. During the same period of time the sliding contact arrangement 94 has moved through a similar displacement path, and now will be located above the pair of contacts 98 and 99.

By virtue of this arrangement, it is possible to ensure that a predetermined correct damping measurement value will only be available from the measuring probe 16 for evaluation, if it is delivered to the correct contact pair, in this case contact pair 98 and 99, determined to be the correct pair as a function of the diameter of the coins and only such predetermined correct pair will be bridged as a function of the diameter of the coin.

There will now hereinafter be considered those factors which must be taken into account during the construction of a multiple-type coin checking device, especially when utilizing the principle of signal storage. The heretofore known single-type coin checking devices could be, in principle, arranged in a row adjacent to one another and in this manner it was possible to form a multiple-type coin checking device. Such construction of multiple-type coin checking device would be manifested by the features of a plurality of coin infeed slots and a plurality of coin travelling channels for the coins to be checked, and furthermore would likewise be manifested by a like number of complete checking circuits for evaluation.

However, it is a further aspect of the invention to propose an electronic multiple-type coin checking technique in which the expenditure of components and operational steps for the checking of a number of coins can be drastically reduced and wherein it is possible to undertake a much easier accommodation to certain coin sorts or classifications.

Now in order to simplify and render less expensive the manufacturer of such a multiple-type coin checking device it is proposed according to the invention, first of all, insofar as concerns the mechanical components, to provide only a single coin chute or channel for all coins instead of, for instance, a plurality of coin channels. It is here mentioned that the utilization of a single coin channel for all coins does not constitute a primary aspect of this invention since conceptually it is completely possible to also utilize a plurality of coin chutes or channels. In such case, the invention proposes the provision of preferably a plurality of parallelly extending coin channels for the coins in front of a single measuring probe, or if there is undertaken a special design of such measuring probe arranging a plurality of such parallel extending channels to pass between the legs of a substantially U-shaped measuring probe or between the oppositely situated probes of a pair of measuring probes.

The arrangement and design of a substantially U-shaped measuring probe and a pair of measuring probes incorporating two oppositely situated measuring probe elements is thought not yet to have become known in the coin checking art. Although it is conceiveable to use, as is of necessity the case if a number of complete coin checking devices are arranged next to one another in a row, a separate coin channel and thus for each coin its own measuring probe and its own evaluation circuit, yet a further aspect of the invention preferably contemplates using for all coins only a single measuring probe and only a single evaluation circuit.

Now if this single measuring probe is intended to monitor the common coin channel for all coins, then, as far as the measuring operation is concerned there are no significant technological drawbacks. Even if the coin channel is designed such that it is possible for the thickest and largest coin of a coin class or type to pass through such coin channel with sufficient play, then, still all three proposed embodiments of measuring probe arrangements are suitable for monitoring this coin channel.

According to one proposal of the invention it is possible for the measurement operation to utilize a measuring probe which is constructed such that at its one end face there is arranged an oscillating circuit. This oscillating circuit, owing to the magnetic lines of force emanating therefrom can be dampened by coins which move past the end face of the measuring probe. Such preferably inductively operating end-face feelers are already known to the art for other measuring purposes. Depending upon the design thereof, the field of the lines of force is operable over a predetermined area in front of the end face of the measuring probe. The measuring probe can be acceptably designed such that the field of the lines of force of such measuring probe monitor up to three coin channels.

Furthermore, an additional concept of the invention contemplates that in such instance, the different coins are arranged within the individual coin channels in accordance with the ascending or descending gradient of their dampening capability and are then moved past the measuring probes, all as will be explained more fully hereinafter. Depending upon the desired measuring technique one would proceed in different ways.

For instance, let it be assumed that three different coins produce damping measurement values which are very close to one another. Then, it would be possible, for instance, to move the coin having the most pronounced damping qualities past the measuring probe at the smallest spacing therefrom and to move the coin having the slightest damping qualities past and in front of the measuring probe at the largest spacing therefrom. As a result, the now obtained three damping measurement values, which previously were quite close to one another, are disposed at the largest range from one another. In other words: by providing for a varying dimension of the spacing between one side of the coin and the measuring probe, it is possible to achieve, in conjunction with the inventive selection of the coins, that measurement values which could be poorly differentiated from one another because the measurement values were too close to one another are now "spread".

According to the same concepts of the invention, it would also be possible to proceed in a reverse fashion. Thus, it is conceivable to have three different coins producing three different damping measurement values which are situated relatively close to one another. In the event that it is not desired to perform the evaluation of these damping measurement values through the use of three different voltage discriminators (and this embodiment also contemplates that, if desired, it is also possible to include a coin type-related counting signal or the like), rather if it is desired to check only the authenticity of the coins by means of a single threshold value switch (voltage discriminator), then, by undertaking an appropriate displacement of the spacing of the individual coins with respect to the end face of the measuring probe, it is possible to achieve that the previously different measurement values now all have the same amplitude and therefore produce one unitary signal.

In such case, one would proceed in a reverse fashion: The coin which has the slightest dampening characteristic would then be moved past the measuring probe at the smallest spacing therefrom, producing a certain signal peak. The coin with the next highest dampening quality is then laterally displaced from the end face of the measuring probe to such an extent until also its dampening value corresponds to that attained by the first coin. The same procedure is followed for the third coin having the greatest dampening characteristic. This coin is therefore also displaced in lateral direction from the end face of the measuring probe to such an extent that its considerably higher damping value progressively becomes smaller until finally it has reached exactly the value of both of the other coins.

From what has been described and discussed above, it should be apparent that it is possible to obtain, in each instance, a uniform signal from coins of different dampening qualities, because the different dampening qualities are balanced out by appropriately variably spacing of these coins from the end face of the measuring probe and thereby causing such dampening qualities to thus approximate one another.

It is here also to be mentioned that, as already stated heretofore, with the last-mentioned solution only a checking of the authenticity of the coins can be undertaken, and it is not possible to obtain separate signals for each type of coin, for instance for counting them or performing some similar operation.

Therefore, according to a further concept of the invention, in such case, if desired, there would be provided at the end of the coin chutes, shortly after the coins have passed the coin checking mechanism, special contacts arranged in known fashion, in order to obtain counting signals or the like.

According to a further proposal of the invention, it is particularly advantageous to utilize a measuring probe which consists of two oppositely situated components. In this context, there is also applicable the same considerations previously described during the utilization of an end-face scanner element in order to obtain the signal influencing characteristics by appropriate selection of the spacing of the coins from the end face of the probe.

Now in the case where there is used two components or elements for the measuring probe an oscillating circuit would not be dampened, rather there would be employed to advantage a transmitter coil which transmits certain energy to an oppositely situated receiver coil which is matched with respect to the transmitting coil. A coin placed between both coils, as a function of its specific characteristics, would then dampen a no-load or idling amplitude at the receiver coil and thus generate a signal or value typical of the coin.

With this inventive arrangement, the advantage is realized that the front and rear face of the coins practically no longer partake in the measurement operation. This can be explained in that the high transmitter energy practically passes through the coins and the differences of the front and rear side of the coin have only a very slight effect. This is that much more the case the closer the central point of both measuring coils coincides with the central point of the throughpassing coins. However, it is a particular advantage of this arrangement that the coincidence of the coin center and the center of the measuring device is not an absolute requirement for undertaking an exact measurement operation. Quite to the contrary, just this embodiment enables the performance of a very good and exact measurement of different size coins and also, in this case, generates signals typical or characteristic of the coins.

A further advantage of this inventive arrangement is realized in that by displacing the measurement arrangement in the direction of the floor of a coin channel or in the direction of the upper boundary wall of a coin channel, it is possible to vary the momentary relationship of the center of the measuring arrangement to the center of different size coins, and thereby considerably influence the signal magnitude. As previously explained, the central coincidence of the measuring arrangement and the coin, is optimal in a certain way. This is to be under-stood in that with this arrangement, the properties or characteristics of the material of the coin play a particularly decisive role as far as the measurement result is concerned. Apart from such, but in a relatively small percentage, there is measured the thickness, the diameter and the depth of embossment of the coins.

According to a further concept of the invention, it is possible, however, to construct such a measuring arrangement that it is "diameter-oriented" in that it is arranged further away from the floor of the coin channel.

With this arrangement, the measuring operation is undertaken such that approximately the largest size coin of a coin sort or classification reaches by means of its upper edge, during throughpassage, at least the center of the measuring probe, whereas the smallest and slightest dampening coin of a coin type classification will just still influence the measuring probe. With such inventive arrangement, the magnitude of influencing the individual components is reversed and now the coin material and diameter determine approximately one-half of the entire measurement result.

By virtue of the inventive arrangement of a pair of measuring probes, while it is not possible to obtain any exact determination of the diameter of the coin itself, still it is possible to achieve in a very simple and inexpensive manner a damping measurement result, by means of which it is possible to ascertain in a not too coarse manner the diameter of the throughpassing coins and at the same time to at least obtain an indication of their coin-typical characteristics.

Now, according to a further proposal contemplated by the invention, it is possible to construct the pair of measuring probes to possess a substantially U-shaped configuration. In that case, two rod-like ferrite core members are connected by a third U-shaped rod member, with a respective separate winding being provided at both legs of the U-shaped construction. In this arrangement the one winding provides a transmitter winding and the second winding the receiver winding. Furthermore, with this arrangement, there are analogously applicable the same comments advanced with respect to the previously discussed arrangement of the circular-shaped pair of measuring probes. However, the U-shaped construction of measuring probe simultaneously affords both advantages which have to be obtained with the previously described arrangement of a pair of measuring probes possessing two different geometric arrangements with respect to the coin channel.

Furthermore, the U-shaped construction of the measuring coil simultaneously permits the determination of the coin-typical material characteristics as well as the measurement of the diameter of the coin.

The foregoing embodiments have described possibilities for simplifying and dispensing with certain mechanical components and as far as the measuring probes are concerned, teaches how it is possible to fabricate an electronic coin checking device for a number of different coin types, the expenditure of equipment of which does not exceed that of a single-type coin checking device.

The invention also proposes especially economically feasible and simple solutions for the evaluation circuit to be described hereinafter. It is here mentioned that with damping measurements of any type, the coins bring about varying dampening of an oscillating circuit or an idling amplitude, and that these different coin-typical damping voltages must be filtered out of a voltage peak by means of suitable threshold value-determining means. By way of completeness, it is here mentioned that the principles of operation of such a threshold value measurement for the determination of the so-called coin-typical or coin-characteristic signals during a damping measurement has been explained in considerable detail in my aforementioned co-pending U.S. application, Ser. No. 55,752, filed July 17, 1970, now U.S. Pat. No. 3,682,286.

In order to minimize the design and expenditure for a multiple-type coin checking device and therefore to solve the objectives of the invention, it is proposed, first of all, according to the invention to associate with each coin type for its typical damping value its own threshold value measuring device and to connect the outputs of all threshold value measuring devices and to associate same with a common sequential circuit arrangement. As a rule, the sequential circuit arrangement consists of a flip-flop, a timing stage, an amplifier for the obtained signals and an electrical actuation mechanism for a coin collecting device.

Thus, the invention proposes constructing a single-type coin checking device and to avoid the expense of utilizing a number of complete adjacently arranged single-type coin checking devices during the checking of a number of coins in that, the signal obtained by the measuring probe is amplified and delivered to a plurality of threshold value detectors. Each such threshold value detector is designed and adjusted to respond to a predetermined coin, wherein furthermore the signals ascertained by the threshold value detectors are again delivered to a common sequential circuit arrangement.

The proposed inventive arrangement of a coin checking device for a plurality of coins possesses the advantage that it is possible to adjust each individual threshold value detector to a "window width" by means of a suitable series resistor, this "window width" taking into account the deviations of the measurement result which may occur for a certain coin type.

However, for certain coin types it is not necessary to provide such a critical, detailed evaluation of the threshold value which takes into account each coin type and therefore brings about a pronounced differentiation with respect to foreign coins.

If these preconditions are present, and therefore for all coins which are to be checked, it is possible to accept equally great deviations within two prescribed threshold values, then it is possible according to a further aspect of the invention to advantageously amplify to a different pronounced degree the obtained damping signals and to deliver such to a common threshold value circuit for evaluation. It must here be remembered that an amplifier is considerably cheaper than a threshold value circuit. When using an amplifier for a number of threshold value circuits, the total installation is considerably more expensive than if a number of amplifiers deliver their signals to a single threshold value circuit.

FIG. 10 illustrates a possible manner of arranging a measuring probe at a coin checking device of the invention. Thus, there is here shown the base or floor 110 of a measuring device as well as the boundary walls 114, 115, 116 and 117 for the three coin channels 111, 112 and 113. At the wall 114 of the measuring channel 111, there is mounted a measuring probe 118. A coin 119 is located within the channel 111, a coin 120 within the channel 112 and a further coin 121 within the channel 113. Due to the inclination of the coin channels 111, 112 and 113, about two axes the three coins 119, 120 and 121, due to the action of the force of gravity, bear against the inner walls 114, 115 and 116 of the three coin channels 111, 112 and 113. Hence, at the point of time when these coins undergo a measurement operation, they assume an exactly spaced position from the front end of the measuring probe 118.

Now in FIGS. 11 and 12 there have been illustrated a number of curves which, starting from a so-called no-load or idling amplitude 122, illustrate the different dampening effects of this no-load amplitude brought about by the coins.

Now the three curves 123, 124 and 125 represented in FIG. 11 illustrate the dampening measurement result which would appear if all three coins of FIG. 10 are conducted through the channel 111. Since the coins 120 and 121 possess a greater dampening characteristic or quality than the coin 119, for the same spacing of such coins to the end face of the measuring probe 118, there results a greater dampening value curve, the apex of which is represented by the lines 127 and 128, respectively, in contrast to the line 126 of the lesser dampening coin 119.

Now as will be observed by referring to FIGS. 11 and 12, by laterally displacing the coins, it is possible to bring about the result that their dampening qualities become less with increasing spacing from the end face of the measuring probe 118, finally attaining a value corresponding to that of the weakest dampening coin. Hence, the curve typical for the coin 119 is also then simultaneously characteristic of the curve for all three coins, and has thus been represented in FIG. 12 by reference character 129, with the corresponding peak value being indicated by 130. Thus, by merely displacing the coins laterally with respect to the front end of the measuring probe 118, it is possible, during checking the coins for authenticity, to determine only a common threshold value instead of three threshold values and therefore to bring about a saving of components for the coin checking installation.

FIG. 13 illustrates a similar exemplary embodiment, but this time for two coins, and wherein for convenience in illustration the same reference characters have been used as were employed in FIG. 10 for the same or analogous components.

FIGS. 14 and 15 show the curve envelopes when using the arrangement depicted in FIG. 13. Thus, more specifically, FIg. 14 illustrates both damping curves for the coins 119 and 120 which will appear if both coins travel through a common coin channel wherein the coins are located at a position from the measuring probe 118 which approximately corresponds to the middle of both illustrated positions of the coins 119 and 120.

Thus, the invention contemplates that the coin 119 having the greatest dampening qualities is located closer to the end face of the measuring probe 118 and, therefore, in contrast to the original damping discussed above provides a considerably greater dampening, whereas the weaker damping coin 120 is located and guided at a point further removed from the end face of the measuring probe 118, and, therefore, further reduces the already relatively weak dampening effect of such coin 120.

As a result, the peak values 126 and 127 of both coins, as best observed by referring to FIG. 15, are clearly differentiated from one another, and, therefore, can be readily separated from one another by the use of suitable hardware.

FIG. 16 illustrates how it is possible to influence the curve and therefore the peak value of the measurement results derived from a pair of measuring probes consisting of two measuring probe elements, by undertaking a lateral spacing-displacement. Thus, more specifically, it will be understood that reference numeral 131 designates a substantially U-shaped coin chute, whereas reference numerals 132 and 133 represent two oppositely situated measuring probe halves. Finally, three different coins are indicated at 134, 135 and 136.

The spacing between a transmitter coil 132 and the reference surface (inner wall) of the coin channel is indicated by the lines 137 and 138, the spacing of the receiver means 133 from the other side of the coin being represented by the lines 139 and 140. The associated curve diagram of FIG. 17 indicates the idling amplitude 141 and the damping measurement curve values 142, 143 and 144 for the coins 134, 135 and 136, respectively.

Due to the geometry of the arrangement and the dimensions of the coins, there results an unfavorable curve shape, manifested by the irregular spacing between the three obtained peak values, as clearly shown in FIG. 17. This result renders more difficult the evaluation of the measurement operation.

FIG. 18, on the other hand, indicates how the same measuring arrangement can be constructed with different geometric relationships and, by virtue of the spatial displacement of the spacing between the transmitter coil and the coin surface on the one hand, as well as the spacing between the receiver coil and the other coin surface on the other hand, it is possible to obtain much more favorable curve envelopes, as best indicated by referring to FIG. 19.

The peak values thus obtained through the geometric displacement of the aforementioned spacing relationships between the components discussed above, now will be seen to have an approximately equal spacing from one another, and, therefore, can be easily ascertained by the use of appropriately designed threshold value circuit means.

FIG. 20 illustrates how it is possible to influence the curve envelopes, and specifically in consideration of the recognition of the diameter of a coin, through the use of a pair of similar measuring probes by displacing same away from the bottom of the coin channel in the direction of the top thereof. More specifically, then, by referring to this figure, it will be recognized that reference numeral 146 designates the bottom or base of a coin channel 145, the top or ceiling of which has been represented by reference numeral 147. Within the coil channel 145 there are arranged two measuring probes 148 and 149, and in front of each such measuring probe there are located three coins 150, 151 and 152 of different size and which, in the exemplary embodiment, can be assumed to be fabricated from the same material. The measuring probe 148 located at the left side of the coin channel 145 is arranged in such a fashion that its central point is equally favorably situated with respect to the center of the smallest coin 150 and that of the largest 152.

Since, as assumed, different materials for the coins are not present, the course of the curves 153, 154 and 155 therefore only signify values resulting from the different coin diameters and therefore surfaces of the coins moving past such measuring probe. FIG. 21 indicates that these differences are only relatively slight.

On the other hand, the measuring probe or feeler element 149 located at the right side of the coin channel 154 is arranged so that it is "diameter-oriented", and specifically is arranged in such a fashion that it is displaced towards the ceiling 147 of this coin channel. With this arrangement, the smallest coin 150 tends to just still influence the measuring probe 149 and therefore only brings about a comparatively slight dampening of the idling-amplitude 156. The peak value has been designated by reference numeral 157. Both of the other remaining coins 151 and 152 bring about a considerably more pronounced dampening, because with the diameter-oriented positioning of the measuring probe 149, as explained above, such coins tend to enter the operable zone of the measuring probe 149 to a much larger degree, and therefore, tend to bring about a considerably greater dampening of the idling-amplitude. Hence the curves indicative of the dampening qualities 151 and 152 with the arrangement under consideration have their peak values indicated at 158 and 159, respectively, as thus shown by referring to the graph of FIG. 22.

It is here further indicated that in the arrangement of FIG. 21, there have been used coins formed of the same type of metal, and accordingly the slight differences of the curves appearing in FIG. 21 is only attributable to the influencing characteristics of the coin diameters. Completely different, and extremely pronounced curve shapes will occur if coins of the same or different diameter, yet formed of different materials, are checked. The curves of markedly different envelope shape which would result in that situation would correspond approximately to the curves depicted in FIG. 22. It is for this reason that the arrangement of the measuring probe 148 in this example can be designated as "metal-oriented".

It should be apparent that a pair of measuring locations designed in accordance with the aforementioned teachings of the invention, and wherein one measuring location is arranged so as to be metal-oriented and the second measuring location arranged so as to be diameter-oriented, can be used to particular advantage for the determination of the authenticity or genuineness of coins, as such will be described more specifically in the hereinafter to be considered block circuit diagrams.

Turning now to FIG. 23, there is illustrated in cross-section a coin channel 161 employing a substantially U-shaped probe or scanning mechanism. The plastic portion of this coin channel 161 has been designated at 160, and the coin disposed within this coin channel 161 has been indicated by reference numeral 162. A connection element 163 serves to interconnect both leg portions 164 and 165 of the bifurcated measuring probe which is equipped with the windings 166 and 167, respectively.

FIG. 24 illustrates a block circuit diagram of a multiple-type-coin checking device which in principle has been constructed in accordance with the teachings of my aforementioned co-pending United States Patent Application, to which reference may be readily had. Still, for the purpose of elucidating the more significant aspects of the invention specific details of the coin checking device circuitry illustrated in such block circuit diagram will now be considered. It is to be understood, firstly, that a coin 203 is placed between a transmitter coil 201 and a receiver coil 202. This coin 203 dampens a starting amplitude at the receiver coil, thereby generating a signal having a predetermined threshold value. This signal is amplified in the subsequently arranged amplifier 204 and is simultaneously delivered to three voltage discriminators 251, 252 and 253. Each of these voltage discriminators 251, 252 and 253 is set to a predetermined "window width" and therefore interrogates a predetermined voltage value which corresponds to the reference voltage value of the coin 203 which is to be checked with the inventive equipment. The outputs of the three voltage discriminators 251, 252 and 253 are electrically coupled together and connected, as shown, with a common flip-flop 206. In accordance with the mode of operation of the voltage discrinimator as described in my aforementioned United States Patent Application, such generates a series of pulses which can consist of one or two pulses and, accordingly, such series of pulses causes the flip-flop 206 to be brought into its switching state or thereafter brought back again into its starting condition and indeed immediately.

During the throughpassage of an optional coin the three voltage discriminators 251, 252 and 253, provided that they are even excited by the damping value of the coins, deliver an appropriate series of pulses and actuate the flip-flop 206. With this arrangement it is assumed that the so-called "window widths" and the double-voltage thresholds which narrow such "window" and designed in such a way that the pulses do not tend to overlap and therefore result in an improper functioning of the flip-flop 206. As soon as the flip-flop 206 has been placed into its switched state, then a signal appears at the AND-gate 208. But, this signal can only be effective if, via the conductor 281, the evaluation of the signal is released and the subsequently connected sequence circuit 209 is energized. In order to preserve clarity in illustration there has been omitted the switching elements which cooperate with the starting or trigger conductor 281, but reference may be made to my aforementioned United States Application for further details. Similarly, there has been omitted any description of the different types of coin collecting circuit arrangements which, however, have been described in considerable detail in the just mentioned United States Application. Finally, in this embodiment as well as in all of the subsequent embodiments, it was not felt necessary for the understanding of the inventive concepts to describe the mechanism for resetting the flip-flop 206 and any eventually further required flip-flops. Once again, such has been described in the United States Application mentioned above, and to which reference may be readily had in the event further clarification of such operation is considered useful.

Now the block circuit diagram of FIG. 24, should make it apparent that the same expenditure of components necessary for the construction of a single type coin checking device is here only enlarged through the use of two additional threshold value switches. Consequently, it is possible to achieve in this manner the desired objective of effectively providing an inexpensive circuit design for a multiple type-coin checking device. Previously it was mentioned that a certain spacing must exist between the voltage thresholds in order to prevent overlapping of the series of pulses (zero or one or two pulses) at the common subsequently arranged flip-flop 206, which pulse series is delivered from the voltage discriminators 251, 252 and 253. It is for this reason that the block circuit diagram of FIG. 24 is not universally applicable for all situations, and therefore instead of using same it is advantageous, according to a further concept of the invention, to provide after each voltage discriminator a respective individual flip-flop. Such an arrangement has been illustrated in FIG. 25.

Because of the similarity of a vast number of components in the circuit diagram of FIG. 25 with those of the circuit diagram of FIG. 24 the same reference numerals have been used for like or analogous components. However, instead of providing, as was the case in the arrangement of FIG. 24, a common flip-flop 206, here there are provided the flip-flops 261, 262 and 263 which are electrically coupled after the three associated voltage discriminators 251, 252, and 253, respectively. In this way, it is possible to positively prevent overlapping of the series of pulses. Depending upon the degree of dampening, each of the three flip-flops 261, 262 and 263 alternately assume a switching state and again their rest state. The outputs of the flip-flops 261, 262 and 263 are separately connected with an OR-gate 207, so that also two flip-flops which have simultaneously assumed their switching state do not interfere with one another. The output of the OR-gate 207 is connected with an AND-gate 208, which, once again is likewise controlled by an external circuit through the agency of the conductor 281. At this period of time, the measurement itself will have already been completed and, therefore, at this period of time it is only possible for one of the three flip-flops to have assumed its switching state and delivered via the OR-gate 207 a signal to the AND-gate 208. The inventive circuitry under consideration ensures that when using a plurality of voltage discriminators there can be prevented, even in the most unfavorable situations, overlapping of the pulses and therefore it is not possible for any erroneous results to occur. As far as the actual measurement operation and the description of the remaining components of the circuitry of FIG. 25 such is analogous to what was previously explained and shown with regard to the circuitry of FIG. 24.

With the circuit design of FIG. 25, it was assumed that the dampening capability of the three coins to be measured was within a relatively narrow range and could be applied by means of a single amplifier to the three voltage discriminators. Yet, this assumption is not valid in all situations. For instance, it is possible that three coins which are to be checked generate quite different signal peaks, and that the smallest signal peak, corresponding to the strongest damping, must be amplified considerably greater than the others, in order to even be able to obtain voltages capable of being evaluated. This situation has been reckoned with by virtue of the block circuit diagram depicted in FIG. 26 and now to be described.

Here, instead of using a common amplifier for the signals delivered by the measuring coil 202, the circuitry of FIG. 26 utilizes three separate amplifiers 241, 242 and 243. Electrically coupled with each such amplifier is an individual voltage discriminator 251, 252 and 253 and an individual flip-flop 261, 262, 263. Further, evaluation of the signals initially occurs by means of an OR-gate 207 and an AND-gate 208 having a starting conductor 281, as previously explained, the OR-gate 207 and the AND-gate 208 being electrically connected in front of the common sequence-circuit 209.

FIG. 27 is a block circuit diagram of a modified form of the invention in which, first of all, there is dispensed with the use of a plurality of voltage discriminators, and furthermore wherein a evaluation circuit for three different coins is designed using only one voltage discriminator.

As already previously mentioned the cost of manufacturing a voltage discriminator including its external circuitry is many times the price of an amplifier. Even a complete measuring probe consisting of transmitter and receiver in addition to an amplifier is not as expensive as a voltage discriminator. Thus, it should be readily apparent that a circuit such as shown in FIG. 27 is particularly interesting for reasons of economy in manufacture. However, it should be understood that the circuit arrangement of FIG. 27 is not useful for all situations. This is so because of two reasons: first of all, this circuit design requires that for all three types of coins which are to be checked there must be present the same window width. Hence, for coin types which do not appreciably differentiate themselves from foreign coins and counterfeit coins, it is not possible to use the block circuit diagram of FIG. 27. Even if for all of the coins to be checked there can be assumed a similar window width, then still the illustrated circuitry can only be used if it is intended to merely check the authenticity of the coins, yet can not be used for the simultaneous reception of signals for counting the individual coin types or the like. In such case, it would be necessary to mount in known manner behind the actual checking circuitry contacts within the coin channel which are actuated by the coins as a function of their dimensions and which, then, in addition to the installed checking circuitry, serves to deliver counting pulses or the like.

Once again in the block circuit diagram of FIG. 27 there have been used the same reference characters as in the preceeding circuit diagrams for the same or analogous components. In this arrangement there have been illustrated a total of three pairs of measuring probes 211/221,212/222 and 213/223, between which probe pairs there are located the coins 231,232 and 233 respectively. Electrically coupled after each pair of measuring probes is a respective individual amplifier 241,242 and 243 as shown. The output of all amplifiers 241,242 and 243 are electrically coupled with a common threshold value-discriminator 205. A flip-flop 206 is connected after the threshold value-discriminator 205. Flip-flop 206 is interrogated by means of the starting conductor 281 via an AND-gate 208 and the common sequence-circuit 209 is operated in the manner already described.

Overlapping of the input pulses or voltage peaks before the threshold value discriminator 205 is prevented, by virtue of the exemplary embodiment of circuitry, in that the pairs of measuring probes are always mounted so as to be spatially separated from one another. Hence, there is thus insured that the pulses arriving via the amplifiers 241,242 and 243 at the threshold value discriminator 205 appear in time-spaced relationship after one another. Accordingly overlapping of the pulses is therefore rendered impossible.

FIG. 28 illustrates a circuit diagram which is an extension of this inventive concept. It will not always be possible, especially when using eight, 10 or even more coins, to provide an individual pair of measuring probes for each coin. It will be necessary, as a general rule, to limit the number of pairs of measuring probes to a maximum of three for reasons of practicality and technical design.

Hence, according to a further aspect of the invention the diameter measurements and the damping measurements are coupled with one another and, in this manner, not only limit the technological expenditure, but also considerably increase the accuracy of the system.

Now in the circuit arrangement of FIG. 28 there is initially undertaken a diameter-oriented evaluation by means of the pair of measuring coils 201/202, which delivers a measurement signal to the amplifier 204. The amplified signal is, in turn, delivered to three voltage discriminators 251, 252 and 253, the outputs of which are coupled with the subsequently connected flip-flops 261, 262 and 263, as shown. The voltage discriminators 251, 252 and 253 and the successively arranged flip-flops 261, 262 and 263 primarily serve to determine certain diameters or diameter groups. A second pair of measuring probes 211/221 likewise delivers a signal which is branched-off to the three AND-gates 301, 302 and 303. The AND-gates 301, 302, 303 operate amplifiers 241, 242 and 243, respectively. It is only possible to use one of these three amplifiers 241, 242 and 243, depending upon the results of the preceeding diameter measurements. The amplification gain of the three amplifiers 241, 242 and 243 are adjusted such that for the three coins checked by way of this embodiment, they always generate the same peak value. It is for this reason that their outputs can be electrically coupled with one another and delivered to a common voltage discriminator 205 possessing the further components considered heretofore in conjunction with the other circuit diagrams and designated by similar reference numerals. The mode of operation of the block circuit diagram under consideration will be more fully explained now in connection with an example.

The coin 203 possesses a specific diameter which, accordingly, with the diameter-oriented arrangement of the pair of measuring probes 201/202 will result in a specific diameter-damping value. Consequently, the voltage discriminator 252 will deliver via the flip-flop 262 a signal which, in turn, fulfills the AND-conditions at the AND-gate 302. The voltage discriminators 251 and 253 are either not energized at all or energized in such a manner that they have delivered two pulses. Thus, the flip-flops 261 and 263 do not deliver any signals to the AND-gates 301, 303, respectively. The coin will then pass the second measuring location and will excite the pair of measuring probes 211/221. The signal emanating from the receiver 221 is delivered to all three AND-gates 301, 302 and 303. The complete AND-conditions are only fulfilled at the AND-gate 302, and therefore only the amplifier 242 can amplify the received signal and deliver such to the threshold value discriminator 205. If such is the case then the diameter and damping value are in the expected relationship to one another. It is to be expected that the coin which has been properly checked by this circuitry is all probability was a true or correct coin.

As previously already explained, it is possible when utilizing a simple measuring technique without resorting to a diameter checking operation to simulate a "correct" result of the threshold value measurement through the use of smaller or larger coins formed of different metals which then coincidently generate the same damping value which is assumed to be a correct one. Such would not be possible with the inventive circuitry of FIG. 28. A smaller coin formed of a material having a more pronounced damping effect, which upon passing the measuring location 211/221 would have possessed the correct damping value, by virtue of the diameter-preselection via the AND-gate 301, therefore would be delivered to the amplifier 241. Yet, according to the invention this amplifier 241 would be designed to possess a considerably larger amplification factor and, thus the voltage discriminator 205 would not have delivered thereto the reference-voltage, rather a considerably higher voltage would be delivered. Thus, with this inventive combined measurement of the diameter and the damping value, and not withstanding the presence of a "correct" damping value, it would still be impossible to fool the coil checking device.

FIG. 29 further shows a simplification of the circuitry of FIG. 28. Here again the reference numerals generally correspond to those employed in FIG. 28 for the same or analogous components. Furthermore, what was previously stated with regard to the diameter-measurement undertaken by the pair of measuring probes 201/202 is equally applicable for this circuit arrangement.

In contrast to the previously discussed circuit arrangement of FIG. 28, here with the circuitry of FIG. 29 the receiver coil 221 of the pair of measuring probes 211/221 delivers the signal to an amplifier 240 which then amplifies such signal to the same degree irrespective from which coin it emanates. This considerably amplified signal is then conducted via one of the three AND-gates 301, 302 and 303. The AND-gates are in a preparatory state, as already heretofore explained. Arranged after the AND-gates 301, 302 and 303 are the resistances 341, 342 and 343 which reduce the amplified signals in each instance by a certain predetermined value and bring such signals to a uniform level. The attenuated signals are delivered via a common conductor or line to a threshold value discriminator 205.

The mode of operation and the possibilities of use of this circuit arrangement corresponds to the previously described circuit arrangement of FIG. 28. However, the circuit design of FIG. 29 affords a still further reduction in manufacturing costs. Instead of using three amplifiers there is now only used a single amplifier and both of the amplifiers which have been omitted have been replaced by the three resistance-combinations 341, 342 and 343. Such amount to only a fraction of the costs which would be necessary for two amplifiers.

FIG. 29 therefore simultaneously illustrates the most complete and inexpensive embodiment of circuitry designed in accordance with the heretofore explained inventive concepts.

While there is shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

Claims

Accordingly what is claimed is:

1. A coin checking apparatus for checking different types of coins, comprising circuit means for performing predetermined measurement operations at the coin being checked and for evaluating the thus obtained information, said measuring and evaluation circuit means incorporating a repeating number of components the repeat of which corresponds to the number of different types of coins to be checked, at least one sequence circuit means incorporating coin collecting circuitry and reset circuitry means for the momentarily activated circuit components, said sequence circuit means being utilized for checking all the different types of coins, means providing a common coin channel for all of the different types of coins, mechanism defining a measuring location for monitoring said coin channel for all the different types of coins, said mechanism defining said measuring location comprising two oppositely situated coils, one such coil defining a transmitter means for an alternating magnetic field, the other of said coils defining a receiver means.

2. A coin checking apparatus as defined in claim 1, wherein said two coils possess a transverse axis which is at approximately the same distance from the transverse axes of the smallest and largest coins of the different types of coins to be checked and therefore such measuring location is metal-oriented.

3. A coin checking apparatus as defined in claim 1, wherein said two coils possess a transverse axis which is spaced from the bottom of the coin channel as far as possible, so that the smallest coin of a coin class is just still able to influence the measuring location and therefore such measuring location is diameter-oriented.

4. A coin checking apparatus as defined in claim 1, wherein the lateral spacing of both coils from one another is accommodated to a predetermined fixed coin class to thereby influence the attainable damping measurement values such that said damping measurement values generated by the individual coin types have the most favorable spacing from one another for evaluation purposes.

5. A coin checking apparatus for checking different types of coins, comprising circuit means for performing predetermined measurement operations at the coin being checked and for evaluating the thus obtained information, said measuring and evaluation circuit means incorporating a repeating number of components the repeat of which corresponds to the number of different types of coins to be checked, and at least one sequence circuit means incorporating coin collecting circuitry and reset circuitry means for the momentarily activated circuit components, said sequence circuit means being utilized for checking all the different types of coins, means providing a common coin channel for one or a plurality of coin types, means for monitoring said common coin channel comprising mechanism defining two measuring locations wherein one said measuring location is constructed to be diameter-oriented and the other measuring location is constructed to be metal-oriented, and wherein the measuring location arranged first in said coin channel switches a predetermined current path in an evaluation circuit of the second measuring location as a function of the measurement result obtained by said first-arranged measuring location.

6. A coin checking apparatus for checking different types of coins, comprising circuit means for performing predetermined measurement operations at the coin being checked and for evaluating the thus obtained information, said measuring and evaluation circuit means incorporating a repeating number of components the repeat of which corresponds to the number of different types of coins to be checked, and at least one sequence circuit means incorporating coin collecting circuitry and reset circuitry means for the momentarily activated circuit components, said sequence circuit means being utilized for checking all the different types of coins, means defining a measuring location for monitoring the coins, said measuring and evaluation circuit means further incorporating an amplifier coupled with said measuring location for amplifying signals received therefrom, a plurality of voltage discriminators for receiving the amplified signals from said amplifier, each of said voltage discriminators being set at a response value corresponding to a predetermined coin type.

7. A coin checking apparatus for checking different types of coins, comprising circuit means for performing predetermined measurement operations at the coin being checked and for evaluating the thus obtained information, said measuring and evaluation circuit means incorporating a repeating number of components the repeat of which corresponds to the number of different types of coins to be checked, and at least one sequence circuit means incorporating coin collecting circuitry and reset circuitry means for the momentarily activated circuit components, said sequence circuit means being utilized for checking all the different types of coins, means defining a plurality of measuring locations including at least a first and second measuring location for checking the coins said measuring and evaluation circuit means further comprising a plurality of voltage discriminators and a respective subsequently electrically coupled flip-flop means, the signal generated by the first measuring location to be influenced by a coin being evaluated by said plurality of voltage discriminators and said subsequently arranged flip-flop, said second measuring location possessing a signal conductor and a common amplifier, the output of each flip-flop together with said signal conductor of said second measuring location being electrically coupled with a respective subsequently arranged AND-gate each having an output a common voltage discriminator having an input and set to a predetermined value, and a respective resistance combination electrically coupled between said output of each AND-gate and the input to said common voltage discriminator, said resistance combinations serving to attenuate the variably high voltage peaks in each case by a certain amount so that said voltage peaks can be checked by said common voltage discriminator.