FR2562881A1 - Apparatuses for automatically dispensing metered amounts of liquid and method for automatically exchanging two vessels alternately feeding this apparatus - Google Patents

Abstract

The subject of the invention is apparatuses for automatically dispensing metered amounts of liquid and a method for automatically exchanging two vessels alternately feeding this apparatus. An automatic dispensing apparatus 1 according to the invention comprises a pouring spout 4 which is fed alternately by two removable vessels 9 and 10. Each vessel comprises a tapping (drawing-off) tube 9b, 10b which is immersed as far as the bottom of the vessel and which is connected through an electrovalve (solenoid valve) EV11, EV12 to a pump 13 which feeds a metering container 6 which feeds the pouring spout. The tube of a vessel carries two level sensors, one for a low level B1 and the other for a high level H1. The tube of the other vessel carries a low-level sensor B2. Electronic circuits combine the signals supplied by the sensors in order to produce the logic function F=(H1+B2).B1 and automatically control the electrovalves (solenoid valves) EV11 and EV12. One application is the automatic dispensing of metered amounts of wine in self-service shops.

Description

 Apparatus for automatically dispensing liquid doses and method for automatically switching two tanks alternately feeding this apparatus.

 The present invention relates to apparatus for automatically dispensing liquid doses and a method for automatically switching two tanks alternately feeding this apparatus.

 The technical field of the invention is that of the construction of automatic liquid vending machines, in particular dispensers of precise volumes of beverages or liquid foodstuffs in containers of variable shape belonging to the customers.

 FR patent applications. 81 / 09.053 and FR. 81 / 20.896 (P.F.

GRIMALDI) describe vending machines for liquid foodstuffs and the present invention can be applied to these appliances, it being understood that this example is not limiting and that the present invention can be applied to all automatic liquid dispensers comprising two tanks permutable, in particular to distributors of wine or other food drinks whose quality may be impaired if a tank remains too long during emptying.

 The object of the present invention is to provide means which allow to automatically switch the tanks that feed a vending machine to go from a first empty tank to a second full tank while making it a priority to pump into the tank which is already started. when the empty tank has been replaced by a full tank.

 The invention relates to a method for automatically switching two tanks equipping a liquid dose dispensing apparatus which is fed alternately from each of the two tanks.

 The object of the invention is achieved by a method according to which the surface of the liquid in the first tank is compared at a high level and a low level and the surface of the liquid in the second tank at a low level by means of sensors. the signals emitted by these sensors are combined to level a logic function and, depending on whether this function is positive or negative, is automatically pumped into the first or second vessel.

 An apparatus according to the invention for automatically dispensing liquid doses is of the type comprising two swiveling mobile tanks in which the liquid is stored and a spout which is fed alternately from each of the two tanks.

 An apparatus according to the invention is characterized in that the first of the two tanks comprises a high level sensor and a low level sensor and the second tank comprises a low level sensor and each of the two tanks comprises a removable extraction rod which plunges to the bottom of the tank and each rod is connected through a solenoid valve and through a common pump or through two pumps on said spout and the device further comprises electronic circuits which receive the signals emitted by said level sensors and which combine these to provide a logic function and this logic function controls two relays which automatically control one or the other of the two solenoid valves or one or the other of the two pumps according to said logic function is positive or negative.

 According to a preferred embodiment, each withdrawal rod carries, near its lower end, a downwardly open insulating housing which is composed of a perforated horizontal bottom, which is fixed to the rod and of vertical walls, and said sensor lower level is constituted by two vertical rods which are suspended from said horizontal bottom and which extend inside said housing.

 The invention results in means for automatically managing the drawing of a liquid in two interchangeable tanks equipping an automatic liquid dose dispenser always privileging the tank which is being emptied, that is to say by continuing to pump the liquid contained in this tank until it is completely empty, even if the second tank has been replaced by a full tank.

 The advantage of the device according to the invention lies in the fact that the duration during which a tank is being emptied is reduced to the maximum. If the vats contain wine or other liquids that may oxidize or lose their organoleptic qualities when they remain in contact with air for a long time, the quality of these liquids is not impaired.

 The preferred embodiments of the supports of the low level sensors have the advantage that, in all cases, the emptying of a tank is stopped automatically when the tank is almost empty, which reduces the losses due to volumes of liquid remaining in the bottom of the tanks.

 The presence of a foot valve on each withdrawal rod associated with a low level sensor which is placed by construction in all cases in a plane located very slightly above said valve, causes the draw pump not to risk defusing and avoiding the introduction of air into the suction rod that would completely distort the precise measurement of liquid doses, which must be absolutely avoided on a measuring instrument that delivers tickets indicating a price to pay, according to the distribution of the folume.

 The arrangement of the high and low level sensors, fixed on the removable filling rod which equips each tank and which is transferred from an empty tank to a full tank, enables the entire level comparison device to be transferred at the same time. require no disassembly or adjustment.

 All the materials composing the devices according to the invention are made of plastic material of food grade or stainless steel and they do not risk damaging the liquid in which they are immersed.

The following description refers to the appended drawings which represent, without any limiting character, an exemplary embodiment of the invention,
Figure 1 is an elevational view of a liquid dispensing apparatus.

 Figure 2 is an axial section of a withdrawal rod equipped with high and low level sensors.

 FIG. 3 is an exemplary embodiment of the logic electronic circuits of an apparatus according to the invention.

 FIG. 1 represents a measuring apparatus 1 which distributes doses of a liquid, for example wine, fruit juice or any other drink or liquid food, in receptacles 2, which are takeaway containers, belonging to the client , which can have varying shapes, sizes and capacities. The apparatus 1 comprises a piece of furniture 3 and, on the front face thereof, one or more pouring spouts 4 which are for example articulated about a horizontal axis to adapt to the height of the containers 2 which are placed on a platinum surmounting a sink 5.

Each pouring spout is connected to a measuring container 6 placed between two solenoid valves, a filling solenoid valve 7 located upstream of the container 6 and a draining solenoid valve located downstream of the container 6.

 The measuring container 6 is equipped with electrodes which automatically control the valves 7 and 8 so that the container 6 fills with a precise dose of liquid, then delivers this dose into the container 2 which can receive several successive doses.

 The cabinet 3 contains electronic circuits not shown and a printer which delivers after each filling of a container 2 a ticket indicating the volume of liquid dispensed in the container and / or the price thereof. Such liquid dispensers are described in the FR patents. 81 / 09.053 and FR. 81 / 20,896 (m.p.

GRIMALDI) and it is not necessary to describe them in more detail.

 The liquid to be dispensed is stored in bulk in two tanks 9 and 10 which are placed at the rear of the cabinet or in the latter.

 When a tank is empty it is removed and replaced by a new full tank. Vats 9 and 10 are, for example, enamelled steel tanks or polyethylene tanks of food grade.

Each tank has a manhole at the top which is closed by a plug 9a, 10a, through which passes a withdrawal rod 9b, 10b which plunges to the bottom of the tank and which is removable. The withdrawal rods 9b, 10b are insulating plastic tubes.

 Each of the two withdrawal rods is connected via a solenoid valve EV 11 and EV 12 to the suction of a pump 13 whose discharge is connected to the filling solenoid valve 7.

 Each withdrawal rod has, at the lower end, a foot valve 9c, 10c which prevents the cane from emptying and that air is trapped therein when the cane is immersed in a new tank then sucked, which would distort the dosage.

 Preferably, the withdrawal rods slide through the tank plugs so that the check valves rest in all cases on the bottom of the tank even if it is flexible and deformable. However, in the case where the tanks are rigid, the withdrawal rods may be integral with the plug which in this case is not a threaded plug.

 The dispensing devices according to the invention are used for dispensing beverages in self-service stores, which entails particular constraints for automatic management of the tanks.

 It is not possible to stop the emptying of a tank before it is completely empty because it would cause losses of the remaining beverage in the bottom of the tank. It is also not possible to wait for customers to signal that one tank is empty to move to the next while customers wait.

It is necessary that the suction of the pump 13 automatically switches from a first empty tank to a second full tank at the precise moment when the first tank is empty.

 This automatic tilting is obtained by the automatic closing of the EVIL or EV12 solenoid valve corresponding to the empty tank and the opening of the solenoid valve corresponding to the full tank.

Alternatively, the two Evil and EV12 solenoid valves and the pump 13 can be replaced by two pumps each sucking into a tank and automatically controlling the stopping of the pump that equips the empty tank and starting the pump that equips the tank. full tank.

 Vat management poses another problem. When a first tank has been emptied and the installation has been tilted to the second tank, the emptying rod is taken out of the empty tank, the empty tank is removed and replaced by a full tank in which plunge the cane back. At this time, it is necessary that the pumping continues in the second tank until it is empty to avoid leaving too long a tank during emptying, which could affect the quality of the wine.

 Hereinafter will be described a preferential device for automatic management of the two tanks. This device comprises in the bottom of each tank, a first liquid surface sensor, said low level sensor, which detects the moment when the surface of the liquid in the tank reaches a low threshold which is located very slightly above the valve corresponding foot. The low level sensor consists of two electrodes, respectively two electrodes B1 for the tank 9 and B2 for the tank 10.

 Each pair of electrodes is carried by an insulating support, respectively 14 and 15, which is fixed in the vicinity of the lower end of the corresponding withdrawal rod.

 Figure 2 shows, on a larger scale, an axial section of a withdrawal rod, for example the rod 9b which passes through a threaded plug 9a which can rotate freely around the cane. The rod 9b carries, in the vicinity of the lower end, a housing 14 of insulating material, for example food grade polyethylene which is open downwards. This housing, which is for example cylindrical, has a horizontal bottom 14a which is fixed to the rod at a height equal to the height of the cylindrical wall 14b, so that the lower edge of the cylinder and the lower end of the foot valve 9c are substantially in the same horizontal plane.

 Two electrodes constituted by two vertical stainless steel rods B1 are suspended at the bottom 14a and descend inside the casing 14. The electrodes B1 are slightly shorter than the height of the casing 14, so that the lower ends of the electrodes are located slightly above the bottom level of the container and above the foot valve. The electrodes B1 are connected to two conductors 16 which are fixed to the rod and which come out of the tank. One of the conductors is connected to the ground and the other on an electronic current sensing device. The upper ends of the rods B1 are threaded and fixed to the bottom 14a between two nuts, so that it is possible to adjust exactly the level of the lower end of the electrodes that determines the low threshold.

 The bottom 14a of the cylindrical housing is perforated, for example it comprises one or more slots, to prevent a liquid film remains permanently on top of the bottom 14a when it is out of the liquid. Indeed, such a film could establish a parasitic contact between the heads of the two electrodes which would distort the detection of the low level and could lead to a defusing of the pump and the introduction of air in the cane defusing.

 Given the flow rate of the pump 13 which is relatively low, a length of the electrodes B1, to twist by 100 mm leads to a draining time of the liquid height between the bottom 14a and the bottom of the tank of the order 5 minutes and this time is sufficient so that the film of liquid that could remain on the bottom 14a has time to stole through the perforations.

 The housing 14 surrounds the foot valve and the electrodes.

It delimits a quiet volume and prevents it from forming around the foot valve a swirl of caulk risk that the current could no longer pass between the electrodes before the tank is completely emptied.

 It should be noted that the example shown in FIG. 1 is a preferred non-limiting embodiment. The housing 14 could be replaced by an insulating support fixed near the bottom of each withdrawal rod, for example a rod or a plastic tube which would carry two contacts each connected to a conductor 16. As long as the contacts are immersed in the liquid, which is electrically conductive, the current passes between the contacts.

When the level of the surface of the liquid falls below the two contacts, the current is cut off, but it may happen that a film of liquid remains on the support and establish a parasitic current passage between the two contacts.

 FIG. 2 represents a withdrawal rod 9b which carries, in the vicinity of the upper end, an insulating collar 17 supporting an electrode H1 whose lower end determines a high level close to the top of the tank. The electrode H1 is connected to a conductor 18 which is fixed to the rod and which connects the electrode to an external electronic device. The electrode H1 detects a high level of the surface of the liquid. It can be seen that all the low level sensors B1 and the high level sensor H1 equipping a tank and conductors connecting these sensors to the electronic circuits are integral with the withdrawal rod, so that they pass, together with the cane, from an empty tank to a full tank, without any disassembly of connections.

 FIG. 2 represents high and low level sensors consisting of electrodes that pass a current as long as they are immersed in the liquid. It is specified that these electrode sensors may be replaced by other equivalent liquid surface sensors, for example by float sensors which close or open a contact when the surface of the liquid reaches a given high or low level or by sensors comprising a sealed enclosure which floats on the liquid and which contains a ball which makes contact as long as the enclosure is floating and which cuts off the contact when the enclosure switches over after the surface of the liquid has reached a determined level or else sensors optical or ultrasonic level or any other sensor of equivalent level.

 The single electrode H1 shown in FIG. 1 can be replaced by two stainless steel contacts each fixed to the end of a conductor which connects one to ground and the other to a current detection apparatus.

 Each withdrawal rod may comprise a high level sensor.

 According to a simpler preferred variant, only one of the two tanks comprises a high level sensor H1, for example the rod carrying the sensor B1.

 The operation is as follows.

 When a first tank is empty, for example the tank 9, the other being full, the high level sensors H1 and low B1 of the first tank are out of the liquid and no current flows, which corresponds to the logic signals H1 = O B1 = 0 H2 = 1 and B2 = 1. In this configuration, the EVIL solenoid valve must be closed and the solenoid valve EV12 must be open.

 When the empty tank has been replaced by a new full tank 9, the high and low level sensors of the tank 9 are immersed in the liquid, a current flows between the electrodes and the ground which corresponds to the logic signals H1 = 1 B1 = 1.

 On the other hand, if the second tank 10 has begun to drain, we have H2 = O and B2 = 1.

We consider the following logical function F = (H1 + B2) .B1
or F = (H1 or B2) and B1.

If the logic signal F = 1 commands the opening of the solenoid valve EV11 and the closing of the solenoid valve EV12, while the complementary logic signal F = O commands the closing of the solenoid valve EV12 and closing the solenoid valve EV11, we solved the problem of tank management and this with a high level sensor H1 in only one of the two tanks. Indeed, the truth table of the function F is as follows

<tb><SEP> H1 <SEP> B1 <SEP> B2 <SEP> H1 + B2 <SEP> F
<tb> C1 <SEP> O <SEP> 0 <SEP> 1 <SEP> 1 <SEP> O
<tb> C2 <SEP> 1 <SEP> 1 <SEP> 1 <SEP> 0 <SEP> 0 <SEP> i <SEP>
<tb> C3 <SEP> 1 <SEP> 1 <SEP> 0 <SEP> 1 <SEP> 1 <SEP>
<tb> C4 <SEP> 0 <SEP> 1 <SEP> 0 <SEP> i <SEP> i <SEP>
<tb> C5 <SEP> 0 <SEP> l <SEP> 1 <SEP> l <SEP> 1
<Tb>
Note that if H1 = 1, B1 is necessarily equal to 1 and that is why the two combinations H1 = 1 B1 = O do not appear in this table.

 Likewise, the combination in which both vats are empty at the same time, that is, B1 = O and B2 = 0 is excluded because this case should not occur.

 If the tank 9 is empty (H1 and B1 = 0) and the tank 10 during emptying (B2 = 1), we find the combination C1 is F = 0.

 Solenoid valve EV12 is open, solenoid valve EV11 is closed. Pump 10 is pumped in. If a new solid tank 9 is introduced (H1 = 1 B1 = 1), the combination C2 is found. F remains equal to zero nothing is changed. The pumping continues in the tank 10.

 When the tank 10 is empty (B2 = 0), we find the combination C3. F changes value.

 Solenoid valves EV11 and EV12 are reversed. Pump is pumped into the tank 9. A new full tank 10 (B2 = 1) is put in place while the tank 9 is being pumped (H1 = 0, 131 = 1). We find the combination C3. F does not change sign. The pumping continues in the tank 9.

 The level in the tank 9 drops below the high level (H1 = 0, B1 = 1) while the tank 10 is being changed (B2 = 0) it is the combination C4.F = 1 the continuous pumping in the tank 9.

 A new full tank 10 (B2 = 1) is put back in place while the level in the tank 9 is intermediate between the high level and the low level (H1 = 0 B2 = 1) it is the combination C5. F remains equal to 1. The pumping continues in the tank 9 until it is empty (H1 = 0 B2 = 0) while the tank 10 is full (B2 = 0).

We find the combination C1 and a new cycle begins again.

It can thus be seen that with two tanks both equipped with a low level sensor (B1, B2), only one being equipped with a high level sensor (H1), it is possible to perform a logic function.
F = (H1 + B2) .B1 which allows to obtain a tank management according to which it is pumped in priority in the tank which is being drained until it is emptied to the low level.

 FIG. 3 shows an embodiment of discrete electronic components, a logic circuit for controlling the automatic management of two tanks. Of course, the circuit according to FIG. 3 can be made in integrated circuits fulfilling the same functions or with a microprocessor programmed to perform the same global logic function.

On the right of FIG. 3 are the three electrodes H1,
B1 and B2 level sensors to which is applied a voltage of + 8 V through a resistor. The voltage on each electrode represents the logic signals H1, B1 and B2 that are at level 0 when the electrode is isolated from the ground and at level 1 when a conductive liquid sets the electrode to the ground.

 Each electrode is connected to two inverters connected in series respectively I1 and I2 for the electrode H1, 13 and 14 for the electrode B1 and I; and 16 for the B2 electrode.

The outputs of the inverters I2 and 16 are connected to two diodes D1 and D2, the outputs of which are connected in parallel, so that the two diodes perform the OR logic function and the logic signal H1 + B2 is found at the output of the two diodes. which is sent on an entry of an AND gate N2. The output of the inverter 14 is connected in parallel to the two inputs of a NAND gate, NA1 which acts as inverter and therefore delivers a logic signal
B1 which is sent on the second input of the gate N2 which therefore delivers a logic signal F = (H1 + B2) .B1 which is the logical function sought.

 The output of the gate N2 is connected to an input of an AND gate N3 and, through an inverter NA2, to an input of an AND gate N4.

The other two inputs of the gates N3 and N4 are connected through an inverter NA3 to a terminal A on which a zero voltage is applied when a customer wishes to be served and a positive voltage when the dispensing device is at rest. When a zero voltage is applied at A, the two gates N3 and N4 are open. Yes
F = 1, a positive signal passes through the gate N3 and this signal controls a relay 01, for example a photocoupler, which controls the opening of the solenoid valve EV11. If, on the contrary F = 0, a positive signal passes through the gate N4 and it controls a relay 02 which controls the opening of the EV12 electrovane.

 The outputs of the inverters 14 and 16 are each connected to a diode and the outputs of the two diodes are connected to a signaling L2 which indicates that B1 or B2 is equal to 1, that is to say that one of the two tanks is empty. The outputs of the inverters 14 and 16 are also connected to the two inputs of an AND gate N1 whose output is connected to a signaling which lights up if B1 and B2 are equal to 1, that is to say if both tanks are empty simultaneously.

 The foregoing description is based on a particular logical function F = (H1 + B2) .B1 which makes it possible to realize the truth table represented above.

 it is specified that this same truth table can be obtained by using other equivalent logical functions, and the logical rules making it possible to construct logical functions that respond to a truth table are well known to technicians who know the BOOLE algebra.

 Hereinafter, in a more general form, the steps of a method according to the invention will be described for automatically switching two tanks 9, 10, the first of which comprises a high level sensor (H1) and a low level sensor (B1 ) and the second of which has a low level sensor (B2).

We pump in the first tank
if the surface of the liquid in the first tank 9 is at a level higher than the low level (B1 = 1) and if, at the same time, the surface of the liquid in the second tank 10 is at a level equal to or lower than the low level (B2 = 0);
or if the surface of the liquid in the first tank 9 is at an intermediate level between the high level and the low level (H1 = 0, B1 = 1) and if, at the same time, the surface of the liquid in the second tank is at a level above the low level (B2 = 1).

And we pump into the second tank 10
if the surface of the liquid in the first tank is at a level higher than the high level (H1 = B1 = 1) and if, at the same time, the surface of the liquid in the second tank is at a level higher than the low level (B2 = 1);
- or if the surface of the liquid in the first tank is at a level lower than the low level (H1 = B1 = 0) and if, at the same time, the surface of the liquid in the second tank is at a level higher than the low level ( B2 = 1).

Claims (6)

 1. A method for automatically switching two tanks (9, 10) equipping a liquid-dispensing device which is fed alternately from each of the two tanks, characterized in that the surface of the liquid in the first tank is compared (9) at a high level (HA) and at a low level (B1) and the surface area of the  in the second tank (10) at a low level (B2) by means of  level sensors and pump into the first tank (9)  if the surface of the liquid in the first tank (9) is at a level higher than the low level (B1 = 1) and if, at the same time, the surface of the liquid in the second tank (10) is at an equal level or  lower than the low level (B2 = 0);  - or if the surface of the liquid in the first tank (9) is  at an intermediate level between the high level and the low level (H1 = 0, B1 = 1) and if, at the same time, the surface of the liquid in the second  tank is at a level above the low level (B2 = 1);  and pump into the second tank (10)  - if the surface of the liquid in the first tank is at a  level above the high level (H1 = B1 = 1) and if, at the same time, the  the liquid side in the second tank is at a level above the low level (B2 = 1);  - or if the surface of the liquid in the first tank is at a level below the low level (H1 = R1 = 0) and if, at the same time, the  face of the liquid in the second tank is at a level higher than the  low level (B2 = 1).  2. Method according to claim 1, characterized in that  lton combines the logic signals emitted by said high level (H1) and low (B1, B2) sensors so as to perform the logical function  F = (H1 + B2) .B1 and, depending on whether this function is positive or negative,  we pump automatically into the first or the second tank.  3. Apparatus for automatically dispensing doses of a  liquid comprising two permutable mobile vessels (9, 10), in which  the liquid is stored and a spout (4) which is fed alternately  each of the two tanks, characterized in that the first of the two tanks comprises a high level sensor (H1) and a  low level sensor (B1) and the second tank comprises a low level sensor (132) and each of the two tanks comprises a withdrawal rod  removable (9b, 10b) which plunges to the bottom of the tank and each rod is connected through a solenoid valve (EV11, EV12) and through a common pump (13) or through two pumps on said spout (4) and the device further comprises electronic circuits which receive the signals emitted by said level sensors (H1, B1, B2) and which combine these to provide a logic function (F = (H1 + B2) .B1) and this logic function controls two relays (01, 02) which automatically control one or the other of the two solenoid valves (EV11, EV12) or one or the other of the two pumps according to whether said logic function (F) is positive or negative.  4. Apparatus according to claim 3, characterized in that each of said withdrawal rods carries, near its lower end, an insulating casing (14) open downwards which is composed of a perforated horizontal bottom (14a) which is fixed to the cane and vertical walls (14b) and said lower level sensor is constituted by two vertical rods (B1) which are suspended from said horizontal bottom and which extend inside said housing.  5. Apparatus according to claim 4, wherein each withdrawal rod comprises a foot valve (9c) characterized in that the lower edge of said housing and the lower end of said foot valve are in the same horizontal plane and are pressed on the bottom of the tank and the lower end of said vertical rods (B1) is located slightly above said horizontal plane.  6. Apparatus according to any one of claims 3 to 5, characterized in that said high and low level sensors, the conductors (16, 18) which connect them to the electronic circuits and said housing are fixed to the withdrawal rod and are transferred with it from an empty tank to a full one without any disassembly or adjustment.