EP0142394B1 - Functioning mode controller for a hydrocarburant dispenser with an electronic calculator - Google Patents

Description

The present invention relates to a device for controlling the operating mode of a hydrocarbon dispenser with an electronic computer.

More specifically, the invention relates to such a control device which can be used in particular in a hydrocarbon distributor in which there is a volumetric sensor making it possible to measure the volume of hydrocarbon distributed which comprises a mechanical outlet whose displacement is representative of the volume measured and a converter for associating with the displacement of the output member a number of pulses representative of the volume delivered. The distributor also includes a set of electronic circuits which make it possible to calculate, from pulses representing the volume measured and from unit price information, the price corresponding to the volume distributed.

It is understood that in such a type of distributor there coexist on the one hand elements in which the hydrocarbon circulates and on the other hand the electrical or electronic circuits which are liable, during their operation, to cause short-circuits or Sparks. It is therefore necessary to separate the area where the electronic circuits are located from the area in which the hydrocarbon circulation pipes are located, for obvious safety reasons.

A first known solution to solve this problem consists in designing from the start a distributor in which there is a first zone in which the members in which the hydrocarbon circulates are housed and a second zone in which all the electronic circuits are located, these two zones. being separated by a bulkhead sealed against hydrocarbon vapors forming an integral part of the distributor frame.

However, there are still currently a very large number of hydrocarbon distributors in which the calculation of the price and its display is done using entirely mechanical components. It is understood that in this case there is no risk of explosion. The distributor frame therefore has no particular sealing structure. Because of the advantages of electronic computers (reliability, flexibility of use, etc.), a large number of owners of hydrocarbon distributors wish to replace their mechanical computer with an electronic computer. However. taking into account the starting structure of the distributor frame, it would be very expensive to set up an oil-tight partition to separate the members in which the hydrocarbon circulates from the computer part.

The generally adopted solution consists of enclosing all the electronic circuits in an explosion-proof box. The mechanical output of the volumetric sensor enters the explosion-proof box through a specially designed bushing. However, it is necessary to be able to introduce a certain number of characteristics into the calculation circuits in order to control the operating mode of the hydrocarbon dispenser. These characteristics consist mainly of the unit price of the hydrocarbon used to calculate the price of the hydrocarbon delivered from the pumped volume. The value of these characteristics must of course be able to be modified. Other characteristics linked to the operating mode may also have to be introduced. For example, it is necessary to be able to control the distributor in autonomous operation or in self-service operation (remote reading). Many other characteristics linked to the operating mode must still be able to be supplied to the computer, in particular to control the display of the total volume debited during a given period or the total amount of the sums invoiced to users during this same period.

The main problem lies in the fact that the characteristic must be transmitted to the calculation circuit through the explosion-proof casing without altering the properties thereof. A first proposed solution consists in using push buttons which pass through the explosion-proof box. while respecting the established rules retaining its explosion-proof characteristics. This requires, at each crossing, to provide special explosion-proof provisions and the structure of the housing is much more complex and the production thereof is therefore much more expensive. Another proposed solution consists in using a single mechanical member which passes through the explosion-proof housing. Relatively complex combinations of movements of this mechanical member must be implemented to allow the introduction of all the necessary characteristics. It is easily understood that such a single member is of a complex mechanical construction and that, in addition, the operating errors are likely to be frequent. In addition, the total number of different characteristics which it is possible to introduce by such an arrangement is necessarily limited.

To overcome these drawbacks, an object of the invention is to provide a device for controlling the operating mode of the dispenser which makes it possible to simplify the production of the explosion-proof box, while making it possible to introduce a large number of characteristics, or characteristic values without complex manipulations.

• - des moyens de commande externes audit distributeur pour élaborer un faisceau d'ondes codé représentatif d'une des caractéristiques de mode de fonctionnement sélectionnée:
• - une fenêtre ménagée dans ladite enceinte et réalisée en un matériau laissant passer ledit faisceau: et,
• - à l'intérieur de ladite enceinte des moyens disposés en regard de ladite fenêtre pour convertir ledit faisceau émis par lesdits moyens externes en des signaux électriques codés et des moyens pour décoder lesdits signaux électriques et élaborer une information représentative de la caractéristique sélectionnée, ladite information étant envoyée audit calculateur.

To achieve this goal, the device for controlling the operating mode of a hydrocarbon dispenser of the type comprising means for measuring the volume of hydrocarbon dispensed, an explosion-proof enclosure, an electronic calculation circuit arranged inside of said enclosure for develop at least the price of the hydrocarbon distributed from the information of volume distributed and operating mode characteristics, and means for displaying at least said price developed by said calculation circuit, according to the invention, is characterized in that it includes:

• - control means external to said distributor for developing a coded wave beam representative of one of the characteristics of the selected operating mode:
• a window made in said enclosure and made of a material allowing said beam to pass: and,
• - inside said enclosure, means arranged opposite said window for converting said beam emitted by said external means into coded electrical signals and means for decoding said electrical signals and developing information representative of the selected characteristic, said information being sent to said computer.

It can be seen that thus the control device does not include any movable member passing through the explosion-proof enclosure.

Preferably, said beam is a coded infrared beam.

• - La figure 1 est une vue de face et en élévation du boîtier anti-déflagrant utilisé dans l'invention;
• - La figure 2 est un schéma simplifié représentant en coupe verticale les organes principaux du distributeur pour montrer le dispositif de commande selon l'invention et son implantation par rapport au distributeur;
• - La figure 3 est un schéma électrique du circuit émetteur de rayon infra-rouge du dispositif de commande selon l'invention; et
• - La figure 4 est un schéma du circuit récepteur de rayonnement infra-rouge du dispositif de commande selon l'invention.

Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment of the invention given by way of non-limiting example. The description refers to the attached drawing in which:

• - Figure 1 is a front view and in elevation of the explosion-proof housing used in the invention;
• - Figure 2 is a simplified diagram showing in vertical section the main organs of the distributor to show the control device according to the invention and its location relative to the distributor;
• - Figure 3 is an electrical diagram of the transmitter circuit of infrared ray of the control device according to the invention; and
• - Figure 4 is a diagram of the infrared radiation receiving circuit of the control device according to the invention.

Referring first to Figures 1 and 2 we will describe the general structure of the operating mode control device and its arrangement relative to the entire distributor. In Figure 2 is symbolized in dotted lines with the reference 10 the distributor frame. An ice 12 of the hydrocarbon dispenser is also shown. Inside the frame, the volumetric hydrocarbon sensor with its mechanical outlet member 16 has been symbolized at 14. It is of conventional type. The sensor 14 is mounted on the hydrocarbon distribution pipe 18. Inside the frame 10 there is also an explosion-proof housing 20. Preferably it consists of two half-shells 22 and 24 connected together by two flanges respectively referenced 22a and 24a and screwed together. Each flange has a joint of sufficient length to ensure the explosion-proof properties. As best seen in Figure 1 the front half-shell 24 of the explosion-proof housing 20 has a window 26 made of a material allowing the infra-red radiation to pass. In FIG. 2, this window is arranged opposite the glass 12. However, preferably, the window 26 is protected by a mask insensitive to infrared and is only accessible after opening a door. from the distributor. The window has characteristics which, moreover, ensure a sufficient mechanical resistance against a possible deflagration. The window is, for example, made of ordinary glass having a thickness of 5mm. It is stuck in the explosion-proof housing 20 on its internal face. Inside the housing 20 there are calculation circuits 30 which receive on the one hand the information of volume distributed, and on the other hand the characteristics of unit price to elaborate the information corresponding to the price of the volume of hydrocarbon distributed . Electronic calculation circuits for hydrocarbon distributors are well known.

The information on the distributed volume is, for example, produced by an optical system 32 which converts the rotation of the shaft 16 into a set of electrical pulses, the number of which is proportional to the rotation and therefore to the volume delivered. The device 32 is for example constituted by a disc 34 integral with the output shaft 16 and provided with slots which pass in front of an optical detector 36. The latter delivers an electrical pulse each time a slot passes in front of the detector 36 Such a device is, of course, perfectly known in itself. The shaft 16 passes through the wall of the housing 20 via a bushing 37 having a flange of joint length sufficient to maintain the explosion-proof properties.

The operating mode control device making it possible in particular to apply the unit price to the calculation circuit 30 comprises on the one hand a portable box 40, therefore outside the distributor 10, and an assembly arranged inside the anti-box explosion 22. In the example described, the housing 40 essentially comprises a control and data input member constituted by the keys 42 of a keyboard, an infrared transmitter 44, and an electronic circuit 46 for converting the action on the control keys 42 in a coded infrared signal which will be delivered by the infrared transmitter 44. Inside the explosion-proof box 20 the control device comprises an optical detector 48 arranged visually opposite the window 26 and therefore capable of receiving the infrared signals delivered by the box 40 when the latter is put in a suitable position, and an electronic circuit 50 for processing the electrical signals delivered by the optical detector 48. These s signals representing for example the unit price of the hydrocarbon are then applied to the calculation circuits 30. Finally, the distributor comprises a display device 52 by example constituted by an intrinsically safe liquid crystal cell and controlled by the computer 30 placed in the explosion-proof box.

It can therefore be seen that the device for controlling the operating mode of the distributor comprises on the one hand, inside the explosion-proof box, an infrared beam receiver associated with a decoding circuit 50 and on the other hand a portable box 40 outside the distributor capable of emitting an infrared beam constituting a signal representative of the characteristic of desired operating mode. Finally, the device comprises the window 26 formed in the explosion-proof box which allows the passage of the infrared beam inside the explosion-proof box.

Of course, the housing 40 is used by the owner of the distributor only when it is necessary to modify one or more operating mode characteristics. The new characteristics are then memorized by the calculation circuits.

It therefore appears that the invention effectively makes it possible to solve the problem posed since the window 26 does not in any way modify the explosion-proof properties of the explosion-proof housing 22 because it does not create any new passage. Furthermore, the coding of the characteristic carried out using the housing 40 allows a large number of combinations and therefore a large number of different characteristics. Finally, the use of this control device is very simple and very reliable since, in the embodiment described, it suffices to press the appropriate key on the keyboard 42.

Referring to Figure 3 we will now describe in more detail the infrared transmitter assembly contained in the control unit 40. First of all there is a set of conductors 60 associated with the keys of the keyboard 42. These conductors are arranged in rows and columns. In the particular case there are 4 rows and 4 columns. Each of the conductors is connected to one of the inputs 62 a to 62 h of a decoder 62. This circuit 62 is for example of the type S D A 2008 manufactured by SIEMENS. The decoder 62 is programmed to deliver on its output 62 i a serial pulse signal representing a binary code of 6 serial binary values associated with each combination of a line and a column corresponding to a key on the keyboard 42. The circuit 62 receives also on its input 62 J a clock signal for example at 455 kHz delivered by the resonator 64. The circuit 62 uses a two-phase coding which is modulated by a carrier constituted by the frequency signal delivered by the resonator 64. The circuit 62 is programmed to additionally deliver a pre-signal to activate the receiver and a start bit. The circuit 62 is preferably supplied only when a key is pressed. It is on standby the rest of the time. For this, its power supply input 62 m is connected to ground via a transistor - 66 serving as a switch and controlled by the signal appearing on the output 62 k of circuit 62 when a key is activated. The coded signal appearing on the output 62 i of the coder 62 is applied to the input of the amplifier constituted by the transistors 68 and 70. The output 72 of this amplifier is connected on the one hand to two emitting diodes in the infra -red 76 and 78 connected in series via the resistor 74, and on the other hand, to an electroluminescent diode 77 via a resistor 79. The diodes 76 and 78 are further connected to the supply voltage by a resistor 78 '. The diode 77 serves as an indication of operation. Thus the emitting diodes in the infrared 76 and 78 emit infrared signals of sufficient energy, and representative of the coded signals delivered by the coding circuit 62. They constitute the transmitting means 44 of FIG. 2.

Referring now to FIG. 4, it can be seen that the receiver circuit 50 of FIG. 2 comprises a photo-diode 81 disposed opposite the window 26 constituting the optical detector 48 of FIG. 2. Its output is connected to the input of a circuit 80 consisting of a variable gain amplifier and a filter mounted in feedback. The output of circuit 80 is connected to the input of a decoding circuit 82. This circuit is for example of the type S A B 3271 manufactured by SIEMENS. This circuit is tuned once and for all on the frequency of the transmitter clock by an oscillating circuit 83. The output 82 a of circuit 82 delivers a coded serial pulse signal representative of the key pressed. The circuit 82 also delivers on its output 82 b a clock signal which is applied to a circuit 84 for shaping and adapting the voltage level. The output 82 a of the circuit 82 is connected to the input 86 a of a shift register 86 via a circuit 85 for shaping and adapting the voltage level. The introduction of the serial information is controlled by the clock signal applied to the input 86 b of the register 86 via the shaping circuit 84. We thus find on the outputs 86 c at 86 h l information delivered by circuit 82 but in parallel form. These outputs 86 c at 86 h from circuit 86 are connected to the computer 30 which thus receives the operating mode characteristic and in particular the characteristic relating to the unit price of the hydrocarbon. These characteristics are stored in a volatile memory of the computer. The register 86 also delivers on its output 86 i a signal 1 to control the introduction into the microprocessor 30 of the characteristics contained in the register 86, and the processing of these characteristics. Finally, the register 86 receives from the computer on its input 86 j a reset signal J when the whole of a code has been introduced into the microprocessor 30.

In the preceding description, only transmission of the control characteristics by radiation has been envisaged. infrared. A radio transmission or an ultrasonic transmission could also be used. However, infrared transmission appears to be the most reliable and the simplest.

Claims (3)

1. Device for controlling the operating mode of a hydrocarbon distributor of the type comprising means (14) for measuring the hydrocarbon volume distributed, an explosion-proof enclosure (20), an electronic computing circuit (30) placed inside said enclosure to deliver at least the cost of the distributed hydrocarbon on the basis of the distributed volume information and operating mode data, and means (52) for displaying at least said cost delivered by said computing circuit, characterized in thaft it comprises:

- external control means (40) outside of said distributor to generate a coded wave beam representative of the selected one of the operating mode data;

- a window (26) provided in said enclosure (20) and made of a material allowing the passage of said coded beam while keeping said enclosure explosion-proof; and, inside said enclosure (20);

- inside said enclosure, means (48) placed opposite said window (26) to convert said beam emitted by said external means (40) into coded electric signals and means (50) for decoding said electric signals and for generating information representative of the selected operating mode; said information being applied to the electronic computing circuit (30).

2. A device according to claim 1, characterized in that said coded beam is a coded infrared beam.

3. A device according to claim 2, characterized in that said external control means (40) comprise a plurality of keys (42), each key being associated with one of said operating mode data, an electronic circuit (46) to deliver an associated signal in response to an action on one of said keys, and a infrared-ray emitter (44) controlled by said associated electric signals to emit infrared rays representative of said associated electric signal.

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