COIN SENSOR SYSTEM FOR VENDING MACHINES

Abstract: Coin sensor system for automatic vending machines, used preferably in all automatic machines and apparatus which are operated by inserting coins and which are power supplied by batteries. The sensor system comprises a metal body (3) integral with the structure of the selector (1) arranged in relation to the introductory slot of coins into the selector wherein the coins bump into each other. Sensor means are provided to detect the mechanical vibrations of the collisions or impacts of coins with the metal part in order to transform such mechanical vibration into an electric vibration, means for cleaning the square wave provided by the comparator, means for activating the switch for supplying power to the electronic coin control and measuring system, and means for desactivating the power supply switch to the electronic control and measuring system.

Description: OBJECT OF THE INVENTION As expressed in the title of the present specification, the following invention comprises a coin sensor system for vending machines, which is mainly useful for inclusion in automatic machines or apparatus, that are coin operated and whose energy is supplied by batteries, in such a way that by means of the existing sensor system, there is a constant sensor for the detection of the passing of coins and a minimum energy consumption. The coin sensor system is arranged close to the coin slot in the selector, and said coin sensor system is based on a sensor that detects and measures the mechanical vibration produced by the dropping of the coins upon a metal piece, integral to the structure itself of the selector, in such a way that the sensor, upon detecting that the coin must be validated, generates a signal in order to apply a supply to the rest of the electronic coin control and measuring system. Hence, the sensor system acts in relation to the hardness of the coin, in such a way that if the element inserted into the selector does not have a certain hardness, the mechanical vibration and the corresponding electric signal produced will be below a reference threshold and the system will remain in standby the inserted element being directly returned, whereby there is a first selection of the elements inserted in accordance with the hardness thereof. FIELD OF APPLICATION The coin sensor system that is presented is especially applicable in automatic machines or apparatus that are coin operated and whose energy is supplied by batteries. BACKGROUND OF THE INVENTION In connection with coin operated automatic machines or apparatus, one can differentiate first of all those that are continuously energized -therefore the energy consumption not being an inconvenience- such as the ones that are connected to the mains, from those machines and apparatus in which it is necessary that energy consumption be reduced to the maximum, because the energy consumed by the apparatus or machine is supplied by batteries. In this way, in certain apparatus or machines, above all if the energy is supplied thereto by batteries, an attempt is made to keep the major electric and/or electronic systems energized the minimum time possible, so that these systems are supplied with energy only when they have to operate, while the rest of the time the system is kept in standby and does not consume energy. Thus, in certain automatic apparatus and machines that are coin operated, close to the coin slot in the selector, there are some photodiodes, upon which the coin operates directly or by means of a mechanism operable by the coins themselves, that makes the electronic system activated so that the coins are validated. Starting from these premises, the materialization of the activating mechanism, can be carried out in many different forms, and thus in general outline we can consider that mechanism that is defined by an L-shaped strip that rotates with regard to its vertex, in such a way that one of its legs is above the coin slot and its other leg is interposed between a pair of diodes, the rotation thereof being caused by the passing of the coins. With this general structure, in order to have an energy saving, what is done is that the photodiodes are not continuously activated, but rather the activation thereof is produced each interval of time for the purpose of producing an energy saving, but at the same time the deactivation periods are so short that they permit the detection of the presence of any coin. In short, they do not represent a totally ideal system for those apparatus or machines whose energy is supplied by batteries. Hence, it is a question of reducing energy consumption, for which purpose an attempt has been made to increase the disconnection intervals of the photodiodes, there being the inconvenience that any coin may be inserted and undetected because the photodiodes that detect the presence of the coin and that energize the electronic validation system are disconnected, the coin is therefore directly returned. With these systems the reduction of energy output has been reduced to "milliamperes". The UK patent application GB 2 173 624 A discloses a low power coin discriminator apparatus. Said low power coin discriminator is initially in dormant state. An inserted coin falls upon a piezoelectric element and a sufficiently large signal causes the micropocessor to activate a LED in a photoelectric sensor. The coin then moves through the photoelectric sensor which determines the net cross-sectional area of the coin. The microprocessor samples the output of the photoelectric sensor to detect the minimum of the light incident upon the sensor, which is at the point of maximum eclipse of the light beam. The micropocessor also samples the output of an integrator which integrates the output of the piezoelectric element to produce a numerical value proportional to the mass of the coin. If the output of the photoelectric sensor indicates that the cross-sectional area of the coin is within acceptable limits, then the measured mass of the coin is also compared to the corresponding limits. If the coin passes both tests, then, it is deemed to be valid. Once the discrimination process is complete, the circuit automatically returns to its original low power, dormant state. DESCRIPTION OF THE INVENTION The present specification describes a coin sensor system for vending machines as defined in claim 1, which is especially useful in all those automatic apparatus and machines, that are coin operated, and whose energy is supplied by batteries, the sensor system being basically constituted by a metal piece integral to the structure of the selector, which is in relation to the coin slot in the selector, and upon which all the coins when being introduced therein knock, there being detecting means for detecting the mechanical vibration of the knocking of the coins against the metal piece, in order to convert said mechanical vibration into an electric signal, cleaning means for cleaning the square wave provided for by the comparator, activating means for activating the switch of energy supply to the electronic coin control and measuring system, and deactivating means for deactivating the switch of energy supply to the electronic control and measuring system. The detecting means of the mechanical vibration of the knocking of the coins against the metal piece, in order to convert said mechanical vibration into an electric signal, are defined by a sensor placed close to said metal piece, considering the electric signal as valid, as long as the signal is above a reference level (Uref) defined by the comparator that the sensor system includes, so that the system is not activated by mechanical vibrations unattributable to the insertion itself of the coins. The cleaning means for cleaning the square wave provided for by the comparator is defined by a Schmitt device that cleans it on the sides, given that when coins are inserted, the coins bounce against the metal piece itself, in such a way that the bounces produced are thus eliminated. The activating means for exclusively activating the switch that supplies energy to the electronic coin control and measuring system is defined by a bistable device that is activated by the Schmitt device switching it at the same time that it activates the switch, feeding the CPU while it operates. The deactivating means of the switch that supplies energy to the electronic control and measuring system is defined by the bistable device that upon being reset by the electronic system itself, once the control and measuring operation has ended, deactivates the switch, the electronic control and measuring system going to the standby state. In order to complete the description that is going to be made hereinafter, and for the purpose of providing a better understanding of the features of the invention, the present specification is accompanied by a diagram, in whose figures in an illustrative and non-restrictive manner, the most characteristic details of the invention are represented. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a front view of the rear part of the coin passage channel, one being able to see the representation of the sensor arranged in relation to the metal piece upon which fall the coins for the purpose of detecting the mechanical vibration of the coins themselves when they knock against the metal piece, integral to the structure of the selector. Figure 2 shows a schematic block diagram, regarding the activation of the electronic system to validate coins, which is activated by the sensor upon picking up the mechanical vibration of the corresponding coins upon falling on the metal piece placed in relation to the coin slot of the selector. DESCRIPTION OF A PREFERRED EMBODIMENT In view of the cited figures and in accordance with the numbering used therein, we can see how the selector (1) has a slot for the coins (2) to be validated, all of the coins falling on a metal piece (3), close to a piezoelectric sensor (4), for the purpose of converting the mechanical vibration into an electric signal. For this purpose, the sensor system has a comparator (5) for the purpose of establishing a minimum reference level (Uref) necessary to consider as valid the electric signal of the piezoelectric sensor (4). Thus, a minimum threshold level necessary to accept the operation of the rest of the electronic coin control and measuring system is established. Likewise, the sensor system comprises a comparator (5), the output of said comparator connected to the input of a Schmitt device (6). In the event that an electric signal originated by the mechanical vibration produced by the knocking of a coin (2) on the metal piece (3) be above the reference threshold set in the comparator (5), the square wave provided for by the comparator (5) will be sent to the Schmitt device, the Schmitt device will clean said square wave on the sides and will activate the bistable device (7); said activated bistable device will subsequently activate the switch (8) of energy supply to the electronic measuring system defined by a CPU (9), said CPU (9) comprising the logic circuit and the analogic circuit. In this way, the bistable device (7) stays activated while the validation of the corresponding coins takes place, and once the system has finished operating, said system will retrigger or reset the bistable device (7) subsequently deactivating the switch (8) and therefore cutting off the supply to the electronic coin control and measuring system. In figure 2 one can see the block that is continuously supplied with energy, that is to say, the sensor (4), the comparator (5), the Schmitt device (6) and the bistable device (7), achieving a reduction of energy consumption down to microamperes, with the big advantage that this represents, above all for all those machines and apparatus whose energy is supplied by batteries. In short, the new coin sensor system sets forth a big advantage even over the Patent P9602334 whose owner is the current applicant. Said patent discloses a coin discriminating system, which is based on the inclusion of a solid body inlaid integrally in one of the walls of the passage channel of the coins to be validated, projecting slightly with regard to the level of the wall towards the passage channel in such a way that all the coins knock against said solid body that has a curved surface in order to allow the coins to continue rolling, the mechanical vibration produced during the knocking of the coins being converted into an electric signal by means of a sensor or transducer in order to validate the coins.

Claims: A coin sensor system for activating vending machines comprising, a metal piece (3) integral to a structure of a selector (1), arranged in relation to a coin slot in the selector upon which a coin (2) knocks when entering said selector, detecting means (4) for detecting a mechanical vibration of a knocking of a coin against the metal piece (3) in order to convert said mechanical vibration into an electric signal, said detecting means being a sensor (4) a switch (8) for connecting and disconnecting energy supply to an electronic coin control and measuring system (9) said sensor system characterized in that it further comprises comparing means for comparing the electric signal provided for by the sensor (4) with a predetermined threshold value defined in a comparator (5) cleaning means (6) for cleaning a square wave provided for by the comparator (5), activating means (7) wherein the output of said activating means is connected to a switch (8), said activating means activating said switch (8) when receiving an electric signal being representative of the mechanical vibration and said electrical signal is higher than the predetermined threshold value defined in the comparator (5) deactivating means (7) wherein the output of said deactivating means is connected to a switch (8), said deactivating means deactivating said switch (8). A coin sensor system for activating vending machines, according to claim 1, characterized in that the detecting means (4) is defined by a sensor (4) arranged close to the metal piece (3), considering as valid the electric signal, as long as it is above a reference level (Uref) defined by the comparator (5). A coin sensor system for activating vending machines, according to claim 1, characterized in that the cleaning means (6) is defined by a Schitt device (6) that cleans the square wave on the sides. A coin sensor system for activating vending machines, according to claim 1, characterized in that the activating means (7) is defined by a bistable device (7) activated by an electric signal originated in the sensor (4). A coin sensor system for activating vending machines, according to claim 1, characterized in that the deactivating means is defined by a bistable device (7), said deactivating means deactivating the switch (8) upon being reset by the electronic system (9) once the control and measuring operation has been completed. A coin sensor system for activating vending machines, according to claim 1, to be used in automatic machines and apparatus that are coin operated, the energy supply of said machines and apparatus being supplied by batteries.

Inventors: GUINDULAIN VIDONDO FELIX, GUINDULAIN VIDONDO, FELIX, Guindulain Vidondo, Félix
Applicants: JOFEMAR SA, JOFEMAR, S.A.
Application year: 1998
Main classification: G07D5
IPC codes: G07D5, G07F1