US 3169626 A
Description (OCR text may contain errors)
Feb. 16, 1965 TAKESI MIYAGAWA ETAL COIN SELECTOR Filed Nov. 22, 1965 2 Sheets-Shea?I 1 By KEA/1cm KlTAJ/HA @au um.
Feb.- 16, 1965 TA'KE'SI MIYAGAwA r-:rAL 3,169,526
com SELECTOR Filed Nov. 22, 1963 2 Sheets-Sheet 2 AWM/m@ 72x55/ M/rAGAn/A 5y Kev/cw K/rAd/MA United States Patent O 3,169,626 G01N SELECTOR Takesi Miyagawa and Kenichi Kitajima, Nagaolra-cho, Otoknni-gun, Kyoto-tu, Japan, assignors to 'iateisi Denk' Kahushiiri Keisha, Uiryo-ku, Kyoto, Japan, a corporation of Japan Filed Nov. 22, 1963, Ser. No. 325,732
Claims priority, application inpan, Nov. 27, 1962,
37/70,982, S7/53,178; Nov. 28, 1962, S17/71,178;
Mar. 22, 1963, StB/15,061
8 Claims. (Ci. 194-100) This invention relates to coin selectors, and has for its primary object the provision of a new and improved coin selector of electrical type which is capable of discriminating between genuine and spurious coins. I
Coin selectors are widely used in combination with vending machines, and there are many known types which discriminate between genuine and spurious coins by their difference in weight orgdiameter. Some of them accordingly depend for their operation uponthe principle of balance. Others are provided with a hole having a diameter just large enough to pass acceptable coins. Such mechanically operated coin selectors, however, are generally of large size and complicated in mechanism. l
Another object of the invention is, therefore, to provide a new and improved coin selector of electrical type which is simple in construction and reliable in operation.
Still another object of the invention is to provide a new and improved coin selector of electrical type which is capable of selecting coins of a certain type or denomination among coins of diderent types or denominations.
Other objects of the invention will be apparent from the following course of the specication. i
In one embodiment of the invention, the coin selector is so constructed that with a coin introduced into the passage being utilized as one of the electrodes, a condenser is formed, the capacity of which is depended upon for detecting the nature of the coin. In the selector, a portion of the bottom wall of the passage for coins to be tested to t pass through is made up of dielectric material, the outer surface of which has an electrode xedly attached thereto. When a coin to be tested contacts the exposed surface of the dielectric as it travels through the passage, a condenser is formed with that coin and the xed electrode as the condenser electrodes andA the dielectric as the condenser dielectric. The capacity ot the condenser varies with the configuration of the coin now functioning as one of the condenser electrodes. Thus the difference in the capacity of the condenser between ya genuine and a spurious coin can be utilized for discrimination between the two coins.
The invention will be better understoodfrom the following description of preferred embodiments of the same with reference to the accompanying `drawings wherein like reference' numerals denote like parts throughout the various gures and wherein: Y
FIG. 1 shows an embodiment of the invention, Vwith its mechanical parts in section and its electrical portion in a block diagram;
FIGS. 2 to 5 are diagrams showing the condenser in section to illustrate the principle of operation of the invention;
troduced into the passage slides down through it by ICC gravity with its under surface in contact with the upper surface 3 of the bottom wall of the passage 1. In the bottom wall of the passage there is txed a plate 4 of dielectric material having a comparatively high dielectric constant such as barium titanate. The upper surface of the dielectric 4 is uncovered and formed substantially fiat and tiush with the inner surface 3 ofthe passage, while the opposite or under surface thereof has an electrode 5 fixed thereto.
A predetermined distance down the passage 1 from the position of the dielectric 4, the bottom wall of the passage is provided with a door 6 hinged on a shaft 7. The door is normally closed by any suitable means such as for example a spring (not shown). So long as the door is closed, a coin sliding down the passage is directed into an extension 1 of the passage 1. If the door is opened, however, the passage 1 will be connected to a branch 1" into which the coin is shunted.
Immediately above the exposed surface of the dielectric 4 there is disposed an electrode means which comprises an arm 9 of conductive material pivoted on a pin 8 and a roller 1i) also or" conductive material rotatably tted to the free end of the arm 9 and electrically connected to the arm 9. The arm is so mounted that the roller 10 lies in the path of, the descending coin 2. The coin as it slides down strikes the roller 10 and raises it slightly until the upper surface of the coin receives the roller, when a condenser is formed with the dielectric 4 as the condenser dielectric and the coin 2v and the iixed electrode 5 as the condenser electrodes.
Outside the bottom wall of the passage 1 and intermediate the dielectric 4 and the door 6, there is provided a proximity detector 11 which is so constructed as to operate in response to objects of ferro-magnetic material.
passing nearby. The proximity detector may be placed at such a position that the coin rst passes the detector and then the dielectric 4.
The door 6, which is normally closed as previously mentioned, is opened by a suitable means such as an electromagnetic device 12 in the illustrated embodiment.
vWhen the coil 14 of the electromagnet 13 of the device 12 is energized, magnetic attraction acts on the door 6 which is made of magnetic material to pull it open so as to connect the passage 1 to the branch 1".
The fixed electrode 5 and ari-119 arev connected by leads 16 and 17 respectively to the input side of a capacity responsive circuit means 15, the output of which is connected to one of the two input terminals of an OR circuit 18. The proximity detector 11 is connected to the other input terminal of the OR circuit. The arrangements are such that: When a capacity produced between arm 9 and electrode 5 by a coin contacting the dielectric 4 is greater than the capacity produced by a genuine coin in contact with the dielectric, the capacity responsive circuit means 1S produces a reject signal, which is applied to the OR circuit 18; or when a false coin made `of a metal, for example, iron passes the proximity detector 11, the detector produces a reject signal, which is also applied to the OR circuit. The OR circuit is so arranged that upon receipt of a signal fromeither the capacity responsive circuit means 15 or the proximity detector 11 it produces an output signal, which is in turn applied to a time delaying circuit means 19 to actuate the same. The time delaying circuit means actuates an electromagnet actuating means 20, which energizes the coil 14 of the electromagnetic device 12 to open the door o connect the passage 1 to the branch 1".
The time delaying means 19 is provided .to delay the so as to reiect signal produced by the capacity responsive circuit f means 15 so as to open the door 6 at the proper moment after the coin has passed over the dielectric 4 and when it reaches the door on its travel down the inclined passage.
Otherwise, the door once opened would have been closed before the coin had arrived and the coin would be wrongly accepted.
As previously mentioned, the apparatus in accordance with the invention depends. for its operation upon the capacity of a condenser formed with a coin to be tested as one of the condenser electrodes. In condensers, if the dielectric constant of the insulating medium and the distance between -the electrodes. are determined, the capacity is in proportion to the area of the electrodes in contact with the insulating medium or dielectric.
This invention relies on the fact that genuine coins generally have a raised rim and also an inscription, sunken or raised, on both their opposite surfaces, while spurious coins intended to be used in vending `machines or the like are generally fabricated by cutting them out of sheets of metal and have at surfaces without any such raised rim. When such a genuine coin is placed on a plane, contact is made only at the raised rim or raised inscription or both, and the Contact area is smaller than that of such a spurious coin having at surfaces in contact with the plane.
For a better understanding of the principle of operation of the invention, 1ct us refer to FIGS. 2 and 3. The condenser dielectric and the xed electrode in contact with its under surface are indicated by the same reference numerals 4 and 5 respectively as in FIG. l. FIG. 2
shows a genuine coin C placed on the flat exposed upperV surface of the dielectric. On the lower side the coin is in Contact with the dielectric 4 only at the raised rim P, while on its upper side the coin is in contact with an electrode which corresponds to the roller electrode 1d in FIGfl. the two leads 16 and 17 connected to the electrodes 5 and 1Q respectively a capacity whose value is determined by the Contact area of the coin C andthe dielectric 4.
FIG. 3 shows a counterfeit coin C having substantially flat surfaces without any raised rim, placed on the conenser dielectric 4. This coin C contactsl thetlat exposed surface of the dielectric all over its under surface. It is apparent that the contact area of the spurious coin C with the dielectric 4 is larger than the area of the genuine coin C in contact with the same and, consequently, the capacity appearing between leads 16 and 17 is greater in the case of spurious coins than in the case of genuine coins. n
'Keeping the above in mind, let us now return to FIG. l and suppose that the coin 2 that has just been introduced into the passage 1 is genuine. The coin falls by gravity with its under surface in sliding contact with the upper surface of the bottom wall of the passage, until it has come to lie on the exposed upper. surface of the dielectric 4, when a condenser is formed such as schematically shown in FIG. 2, and there comes to exist between leads and 17 a capacity the value of which is determined` `by the Contact area of the coin with the dielectric.
If the capacity responsive circuit means is so arranged as to operate in response not to this capacity value but to capacity values higher than it, no signal is produced from the circuit means 15, and the coil 14 of the electromagnet 13 is not energized, and thedoor 6'remains closed. Then the coin from the dielectric will pass over the door into the acceptance extension 1 of the passage. On the contrary, if the coin 2 is falsehaving no raised rim, its contact area with the dielectric is much larger as shown in FIG. 3 than in the case of a genuine coin as shown in FIG. 2, with the result that there appears between leads 16 and 17 a capacity of a higher value than that resulting from a genuine coin. Then the capacity responsive circuit means 15, responding to this high capacity value, produces As a result, there comes to exist between a signal, which is transmitted through the OR circuit 18 to the time delaying circuit means 19 to actuate the same. The circuit means 19 then actuates the electromagnet actuating device 28, which energizes the electromagneticV device 12 to open the door 6 at the latest at the time the coin has reached the door, so as to connect the passage 1 to the branch path 1, into which the coin is rejected. Then the door is closed. The opening and closing of the door may be regulated by adjusting the time delaying means 19.
' False coins or disks intended for fraudulent use in vending machines or the like are fabricated generally by rough presswork, and the cutting process necessarily causes the edge portion of the coins to be raised on one side thereof. If a false coin having such raised edge or rim on one side is placed on the iiat surface of the dielectric 4 with that side happening to face the flat surface of the dielectric, a smaller contact area will result than would be resulted from a false coin having iiat surfaces without any such raised rim, and it may well be 'that the contact area differs little from that of a genuine coin having a raised rim in contact with the dielectric so that there will be produced between the leads 16 and 17 a capacity of much the same value as with a genuine coin. Then the capacity responsive circuit means 15 does not operate and the door 6 remains closed, so that the false coin will be wrongly selected as genuine.
Toward solving this problem the electrode means of FIGS. 4a, 4b and 5 is directed. In this case, in addition to the dielectric Il to the under surface of which the electrode 5 is lixed, there is provided another dielectric 4' having one of its surfaces iixed to the electrode 10' and the other exposed surface facing the exposed surface of the dielectric 4 in a spaced relation thereto. The two dielectrics 4 and 4 are so arranged that the space between their exposed vsurfaces may be iilled up by a coin to be tested as it passes therethrough. When a coin to be tested contacts the two dielectrics 4 and 4', two condensers are formed, one with the Vcoin and the electrode 10 as the condenser electrodes and the dielectric 4' as the condenser dielectric, and the other with the same coin and the electrode 5 as the condenser electrodes and the dielectric 4 as the condenser dielectric. In FIG.` 4a, the two condensers are serially connected between leads 16 and 17. More advantageously, the two condensers may be connected in parallel as shown in FIG. 4b, because the difference inthe combined capacity of the condensers between a genuine and a spurious coin is larger when they are in parallel than when they are in series.
f the coin is a genuine one C, it contacts the dielectrics 4 and 4 only at the raised rims P as shown in FIGS. 4a and 4b. However, if the coin is a spurious one C' having a raised rim,M on -its one side, on that side the coin contacts either one C' of the dielectrics, say, the dielectric 4 only at the raised rim M, while on the other side the coin contacts the other dielectric 4 all over the surface as shown in FIG.' 5. It will be easily seen that the combined capacity of the two condensers is smaller in the case of the genuine coin than it is in the case of the spurious coin, and that discrimination between Vthe two coins may be elected in the manner previously described.
The problem of false coins having a raised rim on their Yone surface may also be solved by employing the circuit 5. Mention has already been made that with the electrode means of FIG. l or FIGS. 2 and 3, it sometimes becomes impossible to discriminate between genuine coins and false coins having a raised rim on their one side, because they are likely to make little or no difference in the capacity of the condenser formed with each of them .as one of the condenser electrodes. A similar difticulty arises in discriminating coins of a certain type or denomination and coins of another type or denomination. When coins of several different types or denominations are in circulation, it is usual that coins of one type Vis of a diterent material and/ or of a 'different diameter from coins of another type. If coins of a certain denomination it is desired t0 select diler little in diameter from those of another denomination to be rejected, the capacity ofthe condenser formed with a coin of the former denomination as one of the condenser electrodes is practically the same as that of the condenser formed with a coin of the latter denomination as one of the condenser electrodes. In such a case, with the ararngementof FIG. 1, the capacity cannot be Vrelied on for discrimination between the two types of coins. The circuit of FIG. 6 is intended to overcome also this ditliculty.
To explain the circuit in detail, it comprises an oscillator 34 and a resonant circuit 38 inserted in the feed-v back circuit 35 of the oscillator. The oscillator comprises a transistor 31, a capacitor 32 and an inductor 33. In the resonant circuit 38, the condenser formed trom a coin to be tested, the electrode 5 and the dielectric 4 is included as at 36, together with another condenser 36 and an inductor 37. On conditionrth-at the capacity of the resonant circuit Varies very little, if the Q of the resonant circuit 38 and its impedance to the oscillating frequency of the oscillator 34 are too high for a sutlicient amount of current to be fed back to the oscillator, its oscillations do not continue., 0n the contrary, if the Q of the resonant circuit and its impedance are so low as to p'ass a sufficient amount of feedback current, the oscillator can maintain its oscillations.
Suppose that the resonant circuit 38 is so arranged that only with a spurious coin as one of the electrodes of condenser 36 will the Q of the resonant circuit and its impedance in the feedback circuit of the oscillator 34 be of such a value as to start and maintain the oscillations of the oscillator. Then if a spurious coin is introduced and contacts the condenser dielectric 4, the oscillator 34 starts and maintains its oscillations, and an output signal appears at terminal 40 through a diode 39. This signal is transmitted to the time delaying circuit means 19 either directly or indirectly through the OR circuit 18, with the result that the door 6 is opened4 to guide the coin into the rejection branch 1" of the passage 1. On the contrary, if a genuine coin is introduced and contacts the condenser dielectric, the Q value of Vthe resonant circuit changes because the genuine coin is made of a diierent material from the spurious one, and the impedance of the resonant circuit increases above the impedance the circuit had with the spurious coin as one of the condenser electrodes and becomes too high for the oscillator to start and maintain its oscillations. Then no signal appears at terminal 40, with the result that the door 6 remains closed and the genuine coin will be led into the acceptance extension 1 of the passage 1.
When it is desired to select coins of a certain denomination from coins of different denominations, the resonant circuit 38 may be so arranged ythat only with a coin of the desired type or denomination as one of the electrodes of the condenser 36 will the Q of the resonant circuit and its impedance to the oscillating frequency of thev oscillator 34 be of such a value as to prevent starting and maintaining of oscillations. Suppose that a coin of a denomination different from that to be selected is introduced into the passage 1 and contacts the dielectric 4. If the two coins of dilerent denominations happen to be of much the same diameter, the capacity of the condenser 36 formed with each of the coins as one of the condenser electrodes will dier very little from that with the other coin as one of the condenser electrodes. However, so long as the coin now under test is made of a diierent material from the coin of the denomination to be selected, as is generally the case with coins of dilterent denominations, the Q of the resonant circuit is different due to the difference in the materialv of the coin and, consequently, theimpedance thereof diters from the value with the desired denomination and now enables oscillator 34 to start and maintain its oscillations. Then an output signal appears at terminal 40,
Again in FIG. l, the arm 9 may be spring-urged for its` free end to lie in the path of the descending coin so as to be raised by it, and it is required that the strength of such a spring is such that the under surface of the coin is in proper contact with the upper surface of the dielectric 4 and the sliding movement of the coin on the dielectric surface is never prevented. To meet the requirement, the roller 10 may be advantageously provided on the free'end of the arm 9 as shown in FIG. 1. More advantageous, however, are the arrangements of FIGS. 7 'and 8, which are intended to vibrate a contact member to press the coin onto the surface of the dielectric.
Referring yiirst to FIG. 7, the arm 9 and roller 10 of FIG. l is here replaced by a resilient plate 51 secured at one end 60 to a lixed member of the apparatus and provided at the other end with a resilient contact member 53, an insulator 52 being interposed between the plate 51 andthe contact member 53. The location of the contact member is such that its free end lies in the path of the descending coin and spaced a suitable distance apart from the exposed surface of the dielectric 4 for the coin to be able to come into contact with the free end of the contact member 53. An armature 55 is lixedly attached to the resilient plate 51 and is so disposed as to be attracted by an electromagnet 56. From terminals 59 alternating current is supplied to the coil 57 of the electromagnet 56 through a half-wave rectifier 58. It Will be easily understood that because of the half-wave rectifier, the electromagnet is energized only during a half cycle of the alterhating current so as to attract the resilient plate 5l against the force of a coil spring 52 bearing thereagainst. During the next half cycle the electromagnet is deenergized to let the plate free to be returned to its original position by the spring 52'. This is repeated, resulting in vibration of the plate and, consequently, the contact member 53. While vibrating, the contact member touches the descending coin on the surface of the dielectric 4 in such intermittent manner that for one moment it presses the coin onto the upper surface of the dielectric and for the next moment it departs away from the coin to allow it to descend a little further on the dielectric. The descent of the coin, however, is again momentarily checked by the contact member 53again pressing the coin onto the dielectric. In this way, the coin gradually descends until it has passed the contact member 53.
In FIG. 8, there is shown a diaphragm 62 secured at both its ends to a iixed member of the apparatus. The diaphragm has an armature 61 fixed to the central portion of the lower side thereof. A cylindrical casing 65 rnade of an insulating material such as synthetic resin is iixed to the lower face of the armature 61. The casing 65 contains a coil spring 63 and a plunger 64 so urged by the spring that its outer end portion projects out of the casing to lie in the path of the descending coin so as to be able to contact the coin. Facing the upper side of the diaphragm 62 there is disposed an electromagnet 66. When alternating current is supplied to the electromagnet through a half-wave rectifier (not shown), it attracts' the armature 61 intermittently so that the casing 65 moves up and down and the point end of the plunger 64 contacts the coin in the same intermittent manner and with the same result as previously described in connection with FIG. 7.
It should be recognized that the embodiments disclosed herein are merely representative and that further modifications and changes may be made without departing from the true scope and spirit of the invention.
What we claim is: Y
1. A coin selector comprising a coin selection passage having a coin reject path leading therefrom; a dielectric plate having one side exposed to said passage and flush with the inner surface thereof to receive a coin sliding along said inner surface; an electrode connectedto the opposite side of said dielectric plate; electrical coin-contact means disposed in said passage opposite the exposed side of said plate and engageable by said coin whereby upon positioning of said coin therebetween a condenser is formed comprising the contact means, the coin, the dielectric plate and the rst electrode; means fordeecting said coin into said reject path; and capacity responsive circuit means having inputs connected to said electrode and to said contact means and an output connected to said deecting means and operable upon occurrence of a predetermined Value of capacity in said condenser to actuate said deflecting means to reject said coin. j
2. The coin selector defined in claim 1 wherein said electrical coin-contact means comprises an electrically conductive roller engageable by said coin and operable to roll across the surface of said coin while the latter slides across said dielectric plate, and a pivot arm supporting said roller and mounted to pivot transversely to the path of said coin to permit its travel along said passage while engaging said roller.
3. The coin selector dened in claim l wherein said electrical coin-contact means comprises a second dielectric plate and an electrode coupled thereto, said second dielectric plate having a surface disposed opposite the exposed surface of the first-mentioned dielectric plate and operable to be engaged by said coin simultaneously with engagement thereof with said lirst plate whereby dual condensers are formed in series having said coin in cornmon as one electrode. Y
4. The coin selector defined in claim 3 wherein the respective dielectric plates are of a size and relative spacing establishing said predetermined value of capacity in accordance with the surface discontinuity pattern of a selected denomination of coin positionable therebetween.
5. The coin selector defined in claim l wherein said electric coin-contact means comprises a coin-contact member and electrically operable means coupledwith said member for vibrating the same in a direction transverse to the path of said coin, whereby said coin is vibrated during its travel along said passage.
6. The coin selector defined in claim 1 further including a ferro-magnetic material responsive proximity detector located adjacent said passage preceding said reject path and also connected to said deecting means, said detector being operable Vto' actuate said deecting means in response to presence of spurious coins of predetermined ferro-magnetic material.
7. The coin selector defined in claim 1 wherein said capacity responsive circuit means comprises an oscillator having a resonant feedback circuit including said condenser as an impedance-determining element thereof,V
whereby said feedback circuit establishes the operative condition of said oscillator upon occurrence of said predetermined capacity value.
8. The coin selector defined in claim 7 further including a ferro-magnetic material responsive proximity detector located adjacent said passage preceding said reject path and operable to produce an output signal in response to presence of spurious coins of predetermined ferromagnetic material, and an OR circuit having said capacity responsive circuit means and said detector connected as inputs thereto and operable to actuate said deflecting means in response to occurrence of a signal in either of said inputs.
References Cited by the Examiner UNITED STATES PATENTS 2,918,158 1.2/59 Shlank 194-4 SAMUEL F. COLEMAN, Primary Examiner.