EP0085264B1

EP0085264B1 - Coin acceptor or rejector

Info

Publication number: EP0085264B1
Application number: EP19820400162
Authority: EP
Inventors: Ronald C. Davies
Original assignee: Third Wave Electronics Co Inc
Current assignee: Third Wave Electronics Co Inc
Priority date: 1982-01-28
Filing date: 1982-01-28
Publication date: 1986-04-16
Also published as: EP0085264A1; DE3270543D1

Description

The present invention relates to a multiple coin detecting apparatus for discriminating between denominations of coins and genuineness of coins so as to exclude from acceptance any coins which have not been specifically selected for acceptance, comprising:

a) coin directing means of insulating material having a vertical upper section and a vertical accept channel forming a completely free-fall chute for acceptable coins, and a second channel for directing slugs and other unacceptable coins to be predetermined locality;
b) an oscillator circuit having a resonant tank circuit which provides amplitude modulation of the signal produced by the oscillator circuit in accordance with the losses of the tank circuit;
c) said resonant tank circuit having an inductance means positioned completely around the coin directing means such that said inductance means forms an air-cored coil with the coins passing therethrough forming the core of said coil, and the losses of the tank circuit being determined by the metal content of the coin;
d) direction switching means for selectively accepting and rejecting coins and the like in accordance with the respective amplitude of a control signal, said direction switching means comprising a movable mounted member, and an accept solenoid for moving said member to an accept position dependent on its condition of energization.

Such an apparatus is already known from EP-A-16 696. It accepts genuine coins regardless of their type, size, metal content and newness and rejects non-genuine, spurious coins and the like, regardless of their type, size and newness. It may be conveniently incorporated into coin- operated machines and the like. It electronically rejects all non-genuine coins, and the like, regardless of whether they are ferrous or non-ferrous, thereby eliminating the need for permanent magnets or other scavenging devices.
Nevertheless, when a genuine or non-genuine coin, spurious coin, slug, and the like, is dropped in the coin entry of this known apparatus and passes through the inductance means of the resonant tank circuit, it reduces the quality factory Q of said inductance means, thereby increasing the losses of said inductance means and reducing its efficiency and thereby reducing oscillator activity.
The object of the present invention, thereby, is to provide a multiple coin detecting apparatus which overcomes this drawback.
To this end, the present invention relates to a multiple coin detecting apparatus of the above mentioned type, characterized in that:

e) two further air-cored coils are provided which at first are flattened and then folded around the narrow longitudinal sides of said first coil in such a way that
- - the axes of all three coils are parallel and
- - the winding of said further coils protrude a certain small distance over the edges of the narrow longitudinal sides of said first coil at an angle of 10° to 40° in relation to the windings of the first coil;
  and in that
- f) the two further coils have the same number of windings, are connected in series and form secondary coils in relation to the first coil providing a secondary voltage fluctuation being of opposing polarity with the primary coil voltage fluctuation.

The invention also provides a multiple coin- detecting apparatus wherein the primary and secondary voltage fluctuations are fed into independent analog to digital converters and associated R-S flip-flops to provide a digital pattern for evaluating each coin on the bases of genuineness and denomination.
In order that the invention may be readily carried into effect, it will now be described with reference to the accompanying drawings, wherein:

- Figure 1 is a schematic side elevation of an embodiment of the basic coin detecting apparatus to which the present invention relates;
- Figure 2 is a perspective view showing the secondary coil arrangement extending over left-hand and right-hand edges of the primary coil according to the present invention;
- Figure 3 is a top view of Figure 2;
- Figure 4 is a front view of Figure 2;
- Figure 5 is a schematic diagram for processing the oscillator voltage to detect a coin; and
- Figure 6 is a logic circuit of a part of Figure 5.

In Figure 1 of the drawings, a coin receiving chute 21 is shown, which is positioned substantially vertically and which comprises any suitable electrically insulating material such as, for example, a suitable synthetic material such as; for example, acrylic material. The chute 21 has a coin entry 22 at its upper end for admitting coins into said chute. The chute 21 functions as a coin director to guide coins, slugs, spurious coins, and the like, to a predetermined locality 23.
An inductance coil L51 of the resonant tank circuit of an oscillator circuit, hereinafter described, is wound around the chute 21. A coin, and the like inserted in the coin entry 22 drops down the chute 21 through the center of the inductance coil L51 thereby producing losses therein. A direction switch 24 comprising a movable member, controlled in position by solenoids, is movably positioned un the chute 21 in the locality 23. Under the control of solenoids, the direction switch 24 selectively accepts and rejects coins, and the like, in accordance with a control signal provided by the control circuit.
Guides extend from the chute 21 at the locality 23. The guides comprise a reject chute 25 for directing rejected spurious coins, slugs, and the like, to a reject area and an accept chute 26 for directing accepted genuine coins to an accept area. When the direction switch 24 is in the position shown in Fig. 1, it directs a non-genuine or spurious coin 27 into the reject chute 25. When the direction switch 24 is in the position opposite that shown in Fig. 1, it directs a genuine coin 28 into the accept chute 26. The reject chute 25 and the accept chute 26 preferably comprise the same material as the chute 21. A microswitch SW2 is positioned in the accept chute 26 and functions as hereinafter described.
When a genuine or non-genuine coin, spurious coin, slug, and the like, is dropped in the coin entry 22 (Fig. 1) and passes through the inductance coil L51 of the resonant circuit, it reduces the quality factory Q of said inductance coil,-thereby increasing the losses of said inductance coil-and reducing its efficiency and thereby reducing oscillator activity.
In accordance with the present invention an improved oscillator circuit is provided wherein a secondary coil is placed in close proximity to a particular area of the primary coil with its windings forming an angle between ten and forth degrees in relation to the primary windings. When the total number of windings on the secondary coil is equal to the total number of windings on the primary coil, the following novel effect is observed.
The winding of the tank coil according to the present invention is shown in Fig. 2. In that coil, a coil is first wound on a hollow core to provide a hollow primary coil C200. Thereafter, two secondary coils are each separately wound on a solid core, removed from the core and flattened to provide two U-shaped coils. These coils C201 are then folded around the primary coil C200, so that the secondary coils C201 protrude over left-hand and right-hand edges of the primary coil C200 by 3,375 mm and at an angle a of 10° to 40° in relation to the windings of the primary coil C200. The ends of the coils C201 are connected in series.
When any non-ferrous metal is inserted into the tank coil, the primary voltage is decreased. However, with the aforementioned secondary coil structure, the secondary voltage does not follow conventionl transformer action but rather a retrocede action is observed whereby the secondary voltage increases in magnitude. The word 'retrocede' (to give back to, to grant back) most clearly defines this newly observed effect of the granting back of otherwise wasted energy radiated by the material passing through the coil. The ratio of the rise in the retrocede energy effect is surprisingly large compared to the drop of energy in the primary coil. When the oscillator is operating with 6 volts peak-to-peak across L-51, typically the regular drop effect for a brass slug the size of a 50 cent piece causes a drop in primary voltage of 1.25 volts, while the retrocede voltage rise is 2.5 volts.
This increase in energy in the secondary coils is not proportional to the decrease in energy in the primary coil, but both the increase in the secondary energy and the decrease in primary energy are directly proportionate to the material which causes the change. This retrocede action is due in part to the recovery of energy produced by the otherwise wasted Eddy currents radiated by the material. The rise in secondary voltage is surprisingly not strongly dependent on the lateral position of the material in the coil. It appears that the more noble (i.e. the more conductive) the metal used, the retrocede effect is more pronounced.
This retrocede effect in secondary voltage is not present for ferrous materials. However, ferrous materials with some non-ferrous content will produce this effect to a greater or lesser degree depending upon the ratio of the ferrous to the non-ferrous materials. An explanation for this is that while the predominate reason for losses in the primary circuit with non-ferrous materials is due mainly to Eddy current losses, hysteresis losses do not play a major role. Conversely, with ferrous materials, hysteresis losses predmoninate and cancel out what might have been recovered from Eddy currents. This retrocede effect allows two independent parameters to be identified and measured; one parameter related to the amount of non-ferrous material, the other related to the amount of ferrous material.
A practical application for this retrocede sensor is an analyzer for coins which can be used in single or multiple-coin applications.
Coins which are accepted (while all other slugs, spurious and other foreign coins are rejected) are determined solely by the information decoded from the logic available.
According to the present invention single or multiple-coin analysis can be applied to any coin of any size of any country in any combination as well as any desired token or combination of tokens and coins. Metal and other materials with any kind of magnetic or conductive properties may be analyzed in this manner.
It will be understood that the present invention provides an oscillator circuit having a tank coil L51 which is constructed as described immediately above. In conjunction with this further embodiment, Figs. 5 and 6 show components C105, D103, R104, C108, R106, R107, R108, R109, R110, R111 and R112 as forming a diode pump circuit which serves to rectify the oscillation produced by TR101 resulting in a DC voltage across C108, which is proportional to the peak-to-peak voltage across C200. The value of C108 is selected to be large enough to ignore any instantaneous amplitude changes. This provides a reference voltage which can be used to compensate for any drift in the oscillator amplitude. The DC voltage available across C108 (VOLTAGE A) is therefore a function of the long-term amplitude of the oscillator.
Components C104, D101, R105, VR101 D102, C109 and R101 form a similar diode pump circuit providing a separate DC voltage across R101 (VOLTAGE B). In this instance C109 is selected small enough so that instantaneous amplitude changes will be recognized. Therefore the DC voltage across R101 is a function of the instantaneous amplitude of the oscillator. The voltage level across R101 may be preset by VR101 which is connected to the discharge path of the diode pump circuit.
Components D104, R103 and C107 serve to rectify the secondary voltage appearing across the retrocede sensing coils C201. Therefore the DC voltage (VOLTAGE C) appearing across R103, is a function of the instantaneous voltage across L103.
These three separate voltage levels (VOLTAGE A, VOLTAGE B and VOLTAGE C) are utilized in the following manner:

VOLTAGE A is divided by R106, R107, R108, R109, R110, R111 and R112 and is used as a reference for the non-inverting input of a string of voltage comparators Ml-M7. VOLTAGE B is adjusted by VR101 to be slightly above the VOLTAGE A. This voltage is applied to the inverting inputs of the same voltage comparator string M1-M7. In this condition all comparator outputs are low, and will remain so, as long as VOLTAGE B remains slightly higher than VOLTAGE A.

A similar resistor divider network, R115, R116, R117, R118, R119 and R120 is also connected to VOLTAGE A. This network is used as a reference for the inverting input of a separate string of voltage comparators M8-M12. The non-inverting input of these comparators M8-M12 is then capacitively coupled to VOLTAGE C via C111 and R113. In this condition, all these comparator outputs will be low.
The SET input of an R-S type flip-flop is connected to each comparator Ml-M7 output so that, should any comparator momentarily go high, its corresponding R-S flip-flop will be set. All the flip-flop reset inputs are connected together and capacitively coupled to the output of comparator M-1 via C110.
In operation, when a coin passes through the coil configuration primary voltage decreases as already described. Because the coin is in free fall, this reduction in amplitude is only momentary. Therefore, VOLTAGE A remains unaffected while VOLTAGE B drops to the instantaneous value.
The instant that VOLTAGE B falls below the reference voltage of M-1, the output of M-1 will go high and reset all flip-flops via C110. Should VOLTAGE B fall below the reference voltage applied to any of the other comparators M-2, M-3, M-4, M-5, M-6 and M-7, the appropriate outputs will also go high. Any output that is thus rendered high will set its appropriate flip-flop, providing a logic code which corresponds to the analog voltage drop. Whereas the analog voltage drop was momentary, the resulting logic code is held for further digital comparison.
Concurrently with the voltage drop effect, the retrocede effect is also taking place, and depending upon the ferrous or non-ferrous nature of the coin used, VOLTAGE C will be rising during this time. As the voltage rise exceeds the reference voltages on comparators M-8, M-9, M-10, M-11 and M-12, the appropriate outputs of these comparators will be rendered high, thus setting up a similar combination of flip-flops to correspond with this rise in voltage; a direct function of the retrocede effect.
In order to determine which coins are to be validated, the exclusive flip-flop set-up pattern is decoded from the appropriate flip-flop Q and Q outputs. In the example shown in the drawings, the U.S. Five Cent, Ten Cent, Twenty-five Cent, Fifty Cent and Susan B. Anthony One Dollar coins have been decoded. The LOGIC TRUTH TABLES I and II show how this decoding logic was established. The output of each appropriate decoder gate identifies each coin as follows:

5-cent coin-IC-24
10-cent coin-IC-22
25-cent coin-IC-23
50 cent coin-IC-26
SBA $1 coin-IC-25

A low output would indicate recognition of that particular coin.
The outputs of IC-22, IC-23, IC-24, IC-25 and IC-26 will always be high unless rendered low by the exclusive flip-flop pattern corresponding to each of the specified coins. An OR function of these outputs is performed by IC-27, IC-28 and IC-29 causing IC-29 to go low should any of the individual decoders (IC-22, IC-23, IC-24, IC-25 and IC-26 go low.
The output of.lC-29 is connected to one input of a two-input NOR gate IC-30. The other input of this NOR gate is used to inhibit the gate until such time that the coin has completely passed through the sensing coil. This information is available from the output X of M-1 and thus the connection to M-1.
Under these conditions IC-30 can only trigger the one shop formed by IC-31 and IC-32 when both of the following conditions are met:

Condition 1: Coin has made complete passage through the sensing coil.
Condition 2: Coin has been recognized by flip-flops as one to be accepted.

The output of IC-32 is connected via R122 to the base of transistor TR102.
The ACCEPT SOLENOID L104 is connected to the collector circuit of this transistor TR-102. The result is that the solenoid will actuate the coin diverter mechanism whenever any one of the acceptable coins has passed completely through the sensing coil. Any spurious object will not cause this effect.

Claims

1. A multiple coin detecting apparatus for discriminating between denominations of coins and genuineness of coins so as to exclude from acceptance any coins which have not been specifically selected from acceptance, comprising:

a) coin directing means of insulating material having a vertical upper section and a vertical accept channel (21) forming a completely free-fall chute (26) for acceptable coins, and a second channel (25) for directing slugs and other unacceptable coins to a predetermined locality;

b) an oscillator circuit having a resonant tank circuit which provides amplitude modulation of the signal produced by the oscillator circuit is accordance with the losses of the tank circuit;

c) said resonant tank circuit having an inductance means (L51) positioned completely around the coin directing means such that said inductance means forms an air-cored coil (C200) with the coins passing therethrough forming the core of said coil, and the losses of the tank circuit being determined by the metal content of the coin;

d) direction switching means for selectively accepting and rejecting coins and the like in accordance with the respective amplitude of a control signal, said direction switching means comprising a movably mounted member, and an accept solenoid for moving said member to an accept position dependent on its condition of energization, characterized in that:

e) two further air-cored coils (C201) are provided which at first are flattened and then folded around the narrow longitudinal sides of said first coil (C200) in such a way that

- the axes of all three coils are parallel and

- the winding of said further coils (C201) protrude a certain small distance over the edges of the narrow longitudinal sides of said first coil (C200) at an angle of 10° to 40° in relation to the windings of the first coil (C200);

and in that

f) the two further coils (C201) have the same number of windings, are connected in series and form secondary coils in relation to the first coil (C200) providing a secondary voltage fluctuation being of opposing polarity with the primary coil voltage fluctuation.

2. A coin detecting apparatus as defined in claim 1, wherein said certain small distance is substantially equal to 3 mm.

3. A coin detecting apparatus as defined in claim 1, including rectifying means (D103) for rectifying oscillations from said oscillator circuit into a corresponding DC voltage across a capacitor (C105) and proportional to peak-to-peak voltage across said primary coil (C200), said capacitor (C105) being sufficiently large so that instantaneous amplitude changes are negligible and a reference voltage (A) is thereby produced for compensating against drift in the oscillator amplitude, said DC voltage across said capacitor (C105) being a function of the long-term amplitude of said oscillations (figure 5).

4. A coin detecting apparatus as defined in claim 3, including additional rectifying means (D101) for providing a separate DC voltage across a resistor (R105, VR101) and dependent on the instantaneous amplitude of said oscillations (figure 5).

5. A coin detecting apparatus as defined in claim 4, including means (D104) for rectifying voltage across said secondary coils (C201) and appearing across a resistor (R103) connected in parallel with said secondary coil, said voltage (C) across said resistor not being a function of the instantaneous voltage across said primary coil but rather being a function of the amount of non-ferrous metal contained in the coin sample detected by the secondary coil (figure 5).

6. A coin detecting apparatus as defined in claim 5, including a plurality of voltage comparators (M1-M7), said first-mentioned DC voltage (A) being applied to said comparators and comprising a reference for inverting inputs thereof, said second mentioned voltage (B) being substantially greater than said first-mentioned voltage (A) being applied to the non-inverting inputs of said comparators, said comparators having outputs at a low level when said second- mentioned voltage is substantially greater than said first-mentioned voltage.

7. A coin detecting apparatus according to claim 1, wherein said primary and secondary voltage fluctuations are fed into independent analog to digital converters and associated R-S flip-flops to provide a digital pattern for evaluating each coin on the bases of genuineness and denomination.