GB2121580A - Conditional coin acceptance arrangement - Google Patents

Abstract

A conditional coin-acceptance system comprising a first sensor (44) upstream of a mechanical coin obturator (48), a second sensor (46) downstream thereof, circuit means (56 to 64) for producing from the output of the first sensor a timing signal delayed or of extended duration relative to the first signal, logic means (66) operable to produce a coin accept signal as a function of the second and third signals, and latch means (68) whereby the logic means is latched by the fourth signal for the duration of existence of the third signal. (Figure 3). <IMAGE>

Description

SPECIFICATION Conditional coin acceptance arrangement This invention relates to a conditional coinacceptance arrangement for use in a coin controlled machine or equipment, and more especially a conditional coin-acceptance arrangement which includes a coin sensing station which tests a coin for denomination and truth and accordingly causes a coin to be rejected or passed into an accept path, the latter including an accept sensor which checks passage of the coin down the accept path.

Commonly, the accept sensor is constituted by a microswitch. Thus, referring to Figure 1 of the accompanying drawings, a microswitch 10 is located with its operating element 12 projecting into the coin accept path 14. When a coin 16 passes down the path, the microswitch 10 is switched on when the element 12 is deflected by the coin to the position 18.

The element 12 is then further deflected to the position 20 to allow the coin 16 to fall free of the microswitch. The operating element 12 is then restored towards its rest position 22. During such restoring movement, the microswitch 10 switches off when the element reaches the position 24. The microswitch 10 produces a pulse signifying final acceptance of the coin, the width of said accept pulse being dependent upon the size and speed of the coin 16.

However, the important point to note about this conventional accept sensor is that the microswitch 10 has an inherent hysteresis or backlash, indicated by reference 26. A mechanical non-return means, conventionally a non-return pawl 28, can thus be located in this hysteresis region 26 to prevent fraudulent operations by a coin which has been suspended through the mechanism on a thread or the like. Obviously, the non-return pawl 28 can be positioned to prevent recovery of such a coin which has actuated the microswitch to produce an accept pulse. Furthermore, a coin which has fallen free of the microswitch 10, so that the latter has switched off, cannot be pulled back to reoperate the microswitch and thus generate multiple accept pulses, as this would necessitate pulling the coin back past the non-return pawl 28.Moreover, a coin which is jiggled in the region of the microswitch 10, moving the operating element 12 up and down, also cannot give rise to production of multiple accept pulses, because such jiggling can only take place in the hysteresis region below the non-return pawl 28, and owing to this hysteresis the microswitch cannot be switched off to provide the necessary prerequisite to generation of a repeated accept pulse.

Although a microswitch can thus provide all the basic necessary safeguards required of an accept sensor, it does have disadvantages, more especially in that it presents contact problems, contact variations, and risks of non-operation dependent on the weight and speed of a coin, especially bearing in mind that false coins and various combinations thereof with true coins may be employed in an endeavour to effect fraudulent operations.

Somewhat analogous problems can arise in arrangements where true coin sensors are located upstream and downstream of a mechanical gate which deflects a coin either into the accept path or into a reject path.

It is an object of this invention to provide a sensor system, especially but not exclusively an accept sensor system, which also fulfils all the basic safeguards required of such a sensor system, but at the same time overcomes problems of the type outlined above.

According to one aspect of the invention, there is provided an electronic conditional coin-acceptance arrangement, comprising a coin sensor upstream of a mechanical coin obturator, a coin sensor downstream of said obturator, and means whereby a signal signifying coin acceptance is generated as a function of the output signals of the upstream and downstream coin sensors.

According to a second aspect of the invention, there is provided an electronic conditional coinacceptance arrangement, comprising an upstream coin sensing station including a sensor producing a first signal responsively to passage of a coin, a downstream coin sensing station including a sensor producing a second signal responsively to passage of a coin, a timing circuit producing a third signal containing a timing characteristic relating to passage of the coin past the first and second sensors, and a logic circuit whereby production of a signal signifying coin acceptance is generated as a function of the first, second and third signals.

According to a third aspect of the invention, there is provided a coin validating system which includes a final coin acceptance circuit for checking coin movement in a coin acceptance path downstream of a true coin validating station, comprising a coin sensor means adapted to produce a first signal ouput when the coin moves downstream past a first location in said path and a second signal output when the coin moves downstream past a second location in said path which is downstream of the first location by a distance greater than the diameter of any acceptable true coin, circuit means for developing from said first signal a third signal which is time delayed or of extended duration relative to said first signal, logic means operable by the third signal and the second signal to initiate production of a fourth signal signifying coin acceptance in the acceptance path, said logic means being latched by said fourth signal so that one or more repeated second signals during the existence of said third signal will not produce a repeated fourth signal, and a coin nonreturn device located in the coin path between the first and second locations.

Thus, in a preferred arrangement the logic means will only become unlatched at termination of the third signal, which is of timed duration, preferably being terminated at the end of the overall cycle time of the system. A repeated second signal when the third signal has terminated does not fulfil the requirements of the logic means, and therefore cannot lead to generation of a repeated fourth signal.

Preferably, the coin sensor means is constituted by two sensors, one at the first location and one at the second location. Such sensors may be phototransmitters or inductive sensors or any other non mechanical sensors which will be senstive to passage of a coin.

The effect of the latched logic means is to introduce an artificial hysteresis into the accept sensor system. A repeat fourth signal would necessitate that, during the overall cycle time of the coin validating system, a coin is pulled back to the first sensor and then dropped again. This is not possible owing to the provision of the non-return device.

Equally, jiggling the coin in the region of artifical hysteresis below the non-return device will not product repeat accept pulses, because the logic means remains latched by the fist accept pulse.

A practical arrangement of coin accept sensor system in accordance with the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a prior art microswitch accept sensor; Figures 2A and 2B show in diagrammatic manner the physical arrangement of an accept sensor system in accordance with the invention; Figure 3 is a circuit diagram showing the electronic circuitry forming part of the accept sensor system of the invention; and Figure 4 is a waveform diagram.

Referring to Figure 2, the reference 40 denotes an accept path which contains a sorter flap 42 which separates true coins of differeing denominations.

The coin validating system includes a true coin sensor station upstream of the accept sensor station, so that, in normal operation, only true coins will enter the accept path 40.

Two infra-red photosensors 44,46 are respectively located upstream and downstream in the accept path 40, spaced by a distance which is greater than the diameter of the largest true coin 16 to be handled, so that both sensors cannot be obstructed simultaneously. A non-return pawl 48 is located in the path 40 just below the upstream sensor 44. Slots 50,52 in the sorter flap mechanism enable the passage of the infra-red light associated with the sensors 44,46.

In use, the sorter flap 42 is moved, as indicated by arrow 54, dependently on the denomination of the coin which has been verified at the upstream true coin sensor station. The sorter drive forms no part of the present invention and will not be described; however, it is to be noted that the arrangement is such that the same accept sensor system is operative in both positions of the sorter flap 42.

Referring now to Figures 2A and 3, the phototransmitters and receivers of the sensors 44,46 are designated 44A, 44B, 46A, 46B. When sensor 44 is obstructed by a falling coin in the path 40, capacitor 56 is charged via diode 58 by the output from photo-receiver 44B. The falling coin now obstructs sensor 46, and the output from photo-receiver 46B is fed via diode 60 to a first input of NAND gate 62, which at its second input is connected to capacitor 56, at the junction thereof with diode 58. Accordingly, the output of NAND gate 62, high when receiving only the output from 44B, now goes low, causing the output of a following inverter 64 to go high.This high output of inverter 64 is fed back via diode 65 to the said first input of NAND gate 62 whereby, as long as capacitor 56 remains charged, the output of NAND gate 62 is locked low and the output of inverter 64 is locked high.

Conveniently, the capacitor 56 is discharged coin cidentiallywith the end of the overall cycle time of the system. Thus, at the end of the cycle time, the capacitor 56, which during said cycle time can only discharge through high resistance 57, is discharged through diode 59, to which a timed input is applied from a cycle timer (not shown). Resistor 67 ensures that the gate 62 is grounded except when driven high through one of the diodes 60 and 65.

The output of inverter 64 constitutes a signal signifying coin acceptance in the accept path 40. It is fed to logic means 66 which also receives an input from a true coin latch means 68 which is selectively latched by a signal from the cycle timer and a true coin signal derived from a signal comparator means associated with the upstream true coin sensor station, so that the generation of an accept pulse at the output of the logic means 66 is a function of both true coin verification and acceptance in the accept path, during the overall cycle time. In this connection, reference is made to our copending Patent Application No.

The above described system ensures that a high output at inverter 64 can only be produced by a coin moving, i.e. falling, in the correct direction in the accept path, and this constitutes a directional accept sensor system. A second high output could only be produced if, during the overall cycle time of the validating system, a coin could be pulled back to the sensor 44 and then dropped again; however, this is not possible owing to the provision of the non-return pawl 48.

Figure 4 shows the waveforms associated with the arrangement. Waveform 70 denotes the overall cycle time of the validating system, which starts when the entry of a coin is first detected. Waveforms 72 and 74 are the outputs of the sensors 44 and 46, hereinbefore termed the first signal and the second signal, whilst waveform 76 is the output of the capacitor 56 applied to the logic gate 62, herein before termed the third signal. Waveform 78 is the output of the direction accept sensor system from inverter 64. In effect, the signal 78, hereinbefore termed the fourth signal, is a timed signal the duration of which corresponds to the period for which the capacitor 56 is charged, and it again to be noted that this timed signal terminates at the end of the cycle time waveform 70. Waveform 80 indicates the output of a true coin latch 68, and waveform 82 denotes the output of the logic means 66 which effectively constitutes the final accept pulse, dependent both on true coin verification and acceptance in the accept path.

It will be appreciated that the above described arrangement referring to the drawings is by way of example only and may be modified in various ways within the scope of the invention as herein before defined. In particular, in the arrangement described the third signal is an extended duration signal developed from the first signal. However, it is alternatively possible to develop, for gating with the feedback signal in order to effect latching, a third signal which is time delayed or both time delayed and extended relative to the first signal.

Although exemplified with reference to a directional coin acceptance system, the invention is also applicable to other coin sensor arrangements wherein sensors are located upstream and downstream of a mechanical obturator, such as an accept/reject gate.

Claims (9)

1. An electronic conditional coin-acceptance arrangement, comprising a coin sensor upstream of a mechanical coin obturator, a coin sensor downstream of said obturator, and means whereby a signal signifying coin acceptance is generated as a function of the output signals of the upstream and downstream coin sensors.

2. An arrangement according to claim 1, wherein the obturator is a coin non-return device.

3. An arrangement according to claim 1 or claim 2, wherein the output signal from the upstream sensor is utilised to produce a timing signal and the coin acceptance signal is generated as a function of the timing signal and the output from the downstream sensor.

4. An electronic conditional coin-acceptance arrangement, comprising an upstream coin sensing station including a sensor producing a first signal responsively to passage of a coin, a downstream coin sensing station including a sensor producing a second signal responsively to passage of a coin, a timing circuit producing a third signal containing a timing characteristic relating to passage of the coin past the first and second sensors, and a logic circuit whereby production of a signal signifying coin acceptance is generated as a function of the first, second and third signals.

5. An arrangement according to claim 4, wherein the operation of the timing circuit is initiated by the first signal.

6. An arrangement according to claim 5, wherein the logic circuit receives the second signal and the third signal.

7. An electronic conditional coin-acceptance arrangement which includes a final coin acceptance circuit for checking coin movement in a coin acceptance path downstream of a true coin validating station, comprising a coin sensor means adapted to produce a first signal output when the coin moves downstream past a first location in said path and a second signal output when the coin moves downstream past a second location in said path which is downstream of the first location by a distance greater than the diameter of any acceptable true coin, circuit means for developing from said first signal a third signal which is time delayed or of extended duration relative to said first signal, logic means operable by the third signal and the second signal to initiate production of a fourth signal signifying coin acceptance in the acceptance path, said logic means being latched by said fourth signal so that one or more repeated second signals during the existence of said third signal will not produce a repeated fourth signal, and a coin non-return device located in the coin path between the first and second locations.

8. An arrangement according to claim 7, wherein the logic means remains latched until termination of the third signal.

9. An electronic conditional coin-acceptance arrangement substantially as hereinbefore described with reference to the accompanying drawings.