FR2832124A1 - DEVICE FOR DISPENSING A LIQUID OR PASTY PRODUCT - Google Patents

Abstract

The invention concerns a device comprising two feeding chambers (30A, 30B), including each a product intake (EA, EB), a product outlet (SA, SB) and means 34A, 40A, 34B, 40B) for synchronized delivery of specific volumes of product through said outlet. The device comprises a dispensing outlet (18) and selection means (24) for selectively communicating the product outlet (SA, SB) of one of the chambers with said dispensing outlet by isolating therefrom the product outlet of the other chamber.

Description

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 The present invention relates to a device for dispensing a liquid or pasty product, comprising a supply chamber having a product inlet, a product outlet and means for discharging in a determined manner determined volumes of product through said outlet.

 A device of this type is for example known from French patent application No. 2,657,430. It is used to deliver determined quantities of product, in a clocked manner, in containers. In particular, it is connected to a container filling installation, on which the containers are advanced step by step, for parking under a filling station in which determined quantities of product are delivered to the containers.

 The product is initially stored in a pressure tank, to which the product inlet of the supply chamber is connected. The outlet from this chamber is itself connected to a product transport line, which conveys the metered quantities of product to the container filling station.

 The installation in which this station is located can be a container filling installation, and can be used to fill prefabricated containers. It can also be used to manufacture containers in one or more manufacturing stations, in particular by thermoforming, and to fill these containers in a filling station located downstream from the manufacturing stations.

 It may be desired, with the same installation, to fill a certain number of containers with a first product, then to fill other containers with another product. In particular, when the containers are intended to contain a liquid or pasty product of the yogurt type, it is quite frequent that it is necessary to change the flavor of the yogurt. In such a case, most of the time, a main tank containing the basic product, called white mass, is connected to the filling station in a suitable manner. Depending on the perfume chosen, an additive product is brought in by the transport line so as to be mixed with the white mass in the filling station or just upstream of the latter, before the mixture is introduced into the containers. To change the fragrance, we keep the same white mass, but we modify the additive.

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l'autre de ces dispositifs pour alimenter l'un ou l'autre des produits dans la ligne de transport. To allow such product changes, known installations include a first dispensing device connected to a first product reservoir, and a second similar dispensing device connected to a second reservoir. We operate one or

the other of these devices to supply one or other of the products in the transport line.

Such installations have the drawback of not being compact, and of requiring the installation and operation of two separate distribution devices.

 The object of the invention is to improve this state of the art, by proposing a dispensing device which makes it possible to dose and distribute at least two products, independently of one another.

 This object is achieved thanks to the fact that the device of the invention comprises a second supply chamber also having a product inlet, a product outlet and means for delivering in a cadenced manner determined volumes of product through this outlet and the fact that it includes a distribution outlet and selection means capable of selectively communicating the product outlet from one of the chambers with said distribution outlet by isolating the product outlet from the other from this distribution outlet bedroom.

 Thus, the device of the invention comprises two similar supply chambers, each having an outlet. The outputs of the two chambers are connected to the distribution outlet. The entrances to the rooms can be respectively connected to a first and a second tank containing two different products. To change the product delivered by the dispensing outlet, it is therefore necessary to order the selection means to connect the outlet of one or the other chamber to the dispensing outlet.

 Advantageously, for each chamber, the means for discharging in a defined manner determined volumes of product comprise a metering cylinder forming a region of the chamber adjacent to the product outlet, a metering piston movable back and forth in said cylinder, at least one product inlet opening formed in said piston and a shutter member capable of releasing or closing said inlet opening.

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 Generally, the metering cylinder of each chamber is arranged in a lower region of this chamber, close to its outlet.

Thus, the entrance to the chamber, which is connected to a reservoir, is arranged above the cylinder. The cylinder is filled with product contained in the chamber when the piston rises in said cylinder, the intake opening being open to allow the passage of the product. When the piston has moved enough to determine, in the cylinder, the volume of metered product to be discharged through the outlet of the chamber, the inlet opening is closed and the piston is moved down such so that it pushes the product contained in the cylinder in front of it.

 An operation of this type is described in French patent application No. 2,657,430.

 In this prior document, the intake opening is located in the center of the piston, and can be closed by a valve movable vertically relative to the piston, the stroke of which is also vertical.

 One could choose to use a system of this type in each supply chamber of the device according to the present invention.

However, advantageously, the shutter member is a plug, able to be moved with the metering piston in the reciprocating movement of the latter and to be rotated relative to it to release or close said intake opening.

 The shutter member formed by a plug is interesting, insofar as its displacement relative to the piston is easy to control. The rotation of the plug can be controlled precisely, and the fact that the displacement of the plug does not operate in the same direction as the displacement of the piston facilitates the production and control of the device.

 Advantageously, the device comprises a movable plate, means for moving said plate back and forth and clutch means for selectively making the piston of the first supply chamber or the piston of the second supply chamber integral displacement of the stage.

 With these provisions, the means for controlling the movement of the pistons are not specific to each piston, but they control in

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 makes the movement of the plate and, depending on whether one wants to push back by the distribution outlet one or the other of the products, one or the other of the pistons is engaged on this plate. This results in a substantial saving, both for the manufacture and for the maintenance of the device, compared to a situation in which two analogous control devices would be used (each for example of the type described in French patent application No. 2,657,430, having pistons ordered separately).

 In addition, the device according to the invention is more compact, lighter and easier to control. Indeed, the volume of product dosed must be precisely controlled so that the feeding takes place in good conditions in the container feeding station. Consequently, the means for controlling the movement of the pistons constitute important elements of this type of device.

 Thus, advantageously, the plate has a first and a second passage through which pass respectively the piston rod of the first supply chamber and the piston rod of the second supply chamber, a first clutch means able to be moved relative to the plate between a disengaged position in which it allows relative sliding between the plate and the piston of the first chamber and a engaged position in which it prevents this sliding, as well as a second clutch means capable of being moved relative to the plate between a disengaged position in which it allows relative sliding between the plate and the piston of the second chamber and a engaged position in which it prevents this sliding.

 When a piston is disengaged, its rod remains in place in the corresponding passage of the plate, and the latter slides freely relative to this rod, without moving this piston. To engage the piston, it suffices to control the corresponding clutch means, so as to prevent this sliding and thus to drive this piston with the plate. It is preferable to avoid that the two pistons are engaged at the same time or, at least, to avoid moving the stage in such a situation. To do this, the device of the invention may include control means, or safety means preventing the movement of the plate when the two pistons are engaged.

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 (for example cutting off the power supply to the means for moving the plate).

 The invention will be well understood and its advantages will appear better on reading the detailed description which follows, of an embodiment shown by way of nonlimiting example. The description refers to the accompanying drawings in which: - Figure 1 is a diagram showing the general organization of an injection system comprising a dispensing device according to the invention; - Figure 2 is a vertical sectional view of a device according to the invention; - Figure 3 is a sectional view along line III-III of Figure 2; - Figure 4 is a sectional view along the line IV-IV of Figure 2; - Figure 5 is a top view of the device of Figure 2; and FIG. 6 is a front view of FIG. 2, that is to say according to arrow VI of FIG. 3.

 The system of FIG. 1 is used to convey product, for example a liquid or pasty product, such as yogurt or the like, to a dosing and filling station 10 in which this product is supplied in containers 12 which are brought under this station. For example, the product delivered to station 10 results from the mixture of several products. This mixture comprises a basic product or white mass, initially contained in the reservoir R, as well as an additive coming from a reservoir RA or RB and mixed with the white mass in a mixer 14, before being injected into the station dosing. For example, the white mass can be plain yogurt, while the additives contained in the RA or RB tank can be fruit extracts from two different species.

 By means of a distribution device 16, the product contained in the reservoir RA or RB is conveyed, according to determined doses and in a timed manner, in a transport line LT, which brings this product to the mixer 14 in which it is mixed with the white mass from the reservoir R. Indeed, thanks to the distribution device 16, the

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 distribution outlet 18 can be placed in communication with one or other of the products contained in the reservoir RA or RB.

 In the example shown, the injection system is of the type described in French patent application No. 01 13850 filed on October 26, 2001. In the vicinity of the entry of the transmission line connected to the distribution outlet, the system comprises an introduction station 20 which makes it possible to introduce into this line a separating member such as a shuttle which moves in the transport line under the effect of the thrust of the product introduced after it. In the vicinity of the outlet S of the transport line LT, the system comprises an evacuation station 22 which makes it possible to evacuate this separating member. Thus, over the entire length of the transport line LT located between stations 20 and 22, the separating member inserted into this line at station 20 and removed from said line at station 22, makes it possible to separate one from the other the products respectively located downstream and upstream of this member.

 By acting on the selection means 24 of the device 16, it is possible to connect the input of the line LT to one or the other of the reservoirs RA or RB.

When passing from one tank to another, a separating member is introduced into the line LT by the introduction station 20, so that it separates from one another the products initially contained in each of the two tanks. This system also includes a return line LR, which allows the separating member extracted from the line LT in station 22, to return to the introduction station 20. For this, a product such as water can be introduced into the return line LR in order to push the separating member into this line. On this line, the system advantageously comprises a washing station 26, which makes it possible to wash the separating member before its introduction into the introduction station 20.

 This system is described in more detail by the aforementioned French patent application No. 01 13850 filed on October 26, 2001.

 The distribution device 16 comprises two supply chambers, respectively 30A and 30B, each having an input, EA and EB respectively, these inputs being respectively connected to the tanks RA and RB. The selection means 24 make it possible to selectively connect the outlet SA of the chamber 30A or the outlet SB of the chamber 30B to the distribution outlet 18 of the device 16. That of these

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 two chambers which are not connected to the distribution outlet 18 is connected to a purge duct 19 fitted with a purge valve 19 '.

 With reference to FIG. 2, the configuration of the supply chambers 30A and 30B and the means for discharging the products which equip these chambers will now be described in more detail. Thus, the chambers 30A and 30B each comprise a metering cylinder, respectively 32A and 32B, these cylinders being located in the lower part of the chambers 30A and 30B. For each chamber, a metering piston, respectively 34A and 34B, is movable in the metering cylinder. The position of the product inlets EA and EB in the chambers 30A and 30B has been indicated by broken lines, although these inlets are not in the plane of the figure. These inlets are in the upper part of the chambers, and the latter are completely filled with product coming from the pressure tanks, respectively RA and RB.

 The outlet SA of the chamber 30A or the outlet SB of the chamber 30B can be connected, by a selector 24, either to the distribution outlet 18, or to a purge duct 19.

 In this case, the selector 24 is a rotary selector capable of occupying a first position, visible in FIGS. 1 and 2, in which it communicates the outlet SB of the chamber 30B with the distribution outlet 18 and the outlet SA of the chamber 30A with the purge duct 19, and a second position in which the situation is reversed, the SA outlet of the chamber 30A communicating with the distribution outlet 18 and the SB outlet of the chamber 30B communicating with the duct 19.

 The pistons 34A and 34B each have at least one inlet opening, in this case, they each have two openings, 38A, 38'A and 38B, 38'B respectively.

 For each piston, a shutter member, 40A and 40B respectively, is capable of closing or releasing the intake openings. More specifically, in the example shown, the shutter members are constituted by rotary plugs, arranged in the pistons and capable of rotating relative to them. The plugs each comprise at least one intake passage, respectively 42A for the plug 40A and 42B for the plug 40B.

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 Figure 2 shows the plug 40A in its position in which it releases the intake openings 38A, 38'A of the piston 34A, the passage 42A being arranged in register with these openings. On the other hand, the plug 40B is disposed in its closed position of the intake openings 38B, 38'B, and it can be seen that its solid exterior surface is located opposite these openings.

 In this case, the bushels are of the frustoconical type, each piston, respectively 34A, 34B, having a conical cavity in which the bushel is located. The inner periphery of this cavity and the outer periphery of the plug form respectively a first and a second contact surface, which are designated by the references 44A and 44'A for the piston-plug assembly 34A, 40A, the contact surfaces of the piston-plug assembly 34B, 40B, however, is not referenced. For each piston, the plug and the piston can occupy with respect to each other a working position, in which these contact surfaces are in substantially sealed contact, and a washing position in which they are separated. Thus, in Figure 2, the plug 40A has been moved relative to the piston 34A so as to separate the contact surfaces 44A and 44'A. On the other hand, the plug 40B occupies, in relation to the piston 34B, its working position. Moreover, in FIG. 2, the piston 34A is located outside of its metering cylinder, which is linked to the fact that it is in the washing situation and not in the working situation.

 FIG. 2 shows the piston-plug assembly 34B, 40B at the end of the stroke, in which a metered amount of product has been discharged through the outlet SB. From this situation, to admit a new quantity of product into the cylinder 32B, the plug 40B is pivoted so as to place its intake passage 42B in register with the intake openings 38B, 38'B of the piston 34B and we go up this piston (with the bushel) to the top of the cylinder. In this situation, a vacuum is created in the cylinder 32B, and the product contained in the upper part of the chamber 30B naturally tends to fill this cylinder. The piston is then moved upwards until it reaches a defined position so that the volume of product delimited between the high and low positions of the piston corresponds to the volume of metered product to be discharged at each cycle of displacement of the piston. Of course, the high position or the low position of the piston can be

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 adjusted by appropriate means to define the volume of product to be discharged. In this high position, the inlet openings 38B, 38'B are closed by pivoting the plug 40B and the piston 34B is moved downward to push the product contained in the cylinder 32B in front of it.

 The device 16 comprises a shutter 46, disposed downstream of the distribution means 24 or forming part of said means, and making it possible to close the distribution outlet 18 in a clocked fashion. In fact, this outlet is open when the piston of one of the chambers is moved downwards to discharge a metered amount of product in front of it, but it is closed when this piston has reached its low position, so that when the piston rises with its intake openings open, a vacuum is created in the cylinder of this piston.

 In this case, as seen in Figure 3, the shutter 46 is disposed in the conduit forming the distribution outlet 18 and is formed by a rotary valve in two positions.

 The pistons are carried by rods, respectively 35A and 35B, which extend into the metering chambers, respectively 30A and 30B.

They form an integral part of these rods or are fixed to them by any appropriate means. To protect the products contained in the chambers 30A and 30B from contact with the piston rods, protective means such as bellows 48A, 48B are arranged around these rods by being fixed in the upper part to the wall of the chambers. The internal space delimited between the bellows and the piston rods is brought into the ambient air by communication lines not shown in FIG. 2.

 In this case, the piston rods are hollow and control rods for plugs, 41A and 41B respectively extend inside these rods.

 For each metering piston, respectively 34A, 34B, the cavity of the plug rod, respectively 41A, 41B has an inlet located at one end of the rod outside the piston and a communication located at the opposite end. More specifically, in the example shown, the inlet of the cavity of each plug rod is formed by a fitting, respectively 56'A, 56'B, formed in the fitting head, respectively 56A, 56B. For each plug rod, the communication is formed by one or more holes, respectively 57A and 57B, making

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 communicate the plug rod cavity with the outer periphery of the latter.

 For its part, the piston rod, respectively 35A, 35B, has an orifice, respectively 57'A, 57'B which is located outside the supply chamber.

 In the working position, as for the piston-plug assembly 34B, 40B in FIG. 2, a barrier fluid such as sterile air can be injected through the inlet 56'B into the plug stem, out through the 57B communication to circulate in the annular space formed between the outer periphery of the plug rod and the inner periphery of the piston rod, and out of this annular space through the orifice 57'B. This helps prevent bacteria from accumulating in and between the valve rods and piston.

 In the washing position, as for the piston-plug assembly 34A, 40A of FIG. 2, the communication 57A opens in the supply chamber due to the spacing of the contact surfaces 44A, 44'A.

In this position, a cleaning solution can be injected through the inlet 56'A and through the orifice 57'A and this solution flows downwards, through the communication 57A and through the space provided between the piston and a bushel. It can then be evacuated via the purge duct 19.

 The bushels are controlled by the distal ends of their rods, located outside of the chambers 30A and 30B. The control means can for example be rotary pneumatic cylinders.

It can thus be seen that the end of the rod 41B of the plug 40B has a radial projection 41'B, which is arranged in the chamber of a rotary actuator 50B. Depending on whether the air is injected from one or the other side of this protuberance, the rotation of the plug is controlled in one direction or in the opposite direction. A cylinder 50A of the same type controls the rotation of the plug 40A.

 These cylinders are carried by supports, respectively 52A and 52B, themselves carried by the distal ends of the piston rods, respectively 35A and 35B.

 Thanks to return springs, respectively 54A, 54B, each plug is constantly returned to its working position relative to the piston, in which the contact surfaces mentioned above are in substantially sealed contact. For example, these springs

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 are supported on the one hand on a fixed part of the cylinders 50A, 50B mentioned above, and on a connector head, respectively 56A, 56B screwed onto the rods of the plugs. To control the positioning of the plugs in their washing positions, translational displacement cylinders are also carried by the supports 52A, 52B. It can thus be seen in FIG. 2 that the head 59A of the jack 58A requests the displacement of the rod 41A of the plug 40A downwards relative to the piston 38A. For this, the cylinder head presses on the connector head 56A. On the other hand, the jack 58B is not supplied with pressurized fluid and its head 59B remains at a distance from the connector head 56B.

 The displacement of the pistons is guided by guide plates, respectively an upper guide plate 60 and a lower guide plate 62. These plates have through passages fitted with guide bearings 64 with which the rods of the pistons cooperate. In this case, the supply chambers 30A and 30B have their upper ends formed in a body 31 which is fixed to the lower guide plate 62. The plates 60 and 62 are fixed, for example they are fixed together by fastening and bracing means 66.

 The device comprises a movable plate 68 which can move back and forth between these plates. The upper and lower extreme positions of the plate are determined by high and low safety stops, respectively 70 and 72, respectively integral with the plates 60 and 62. These may be cells detecting the position of the plate and stopping the supply of means for controlling the movement of this plate when it reaches a given level with respect to said cells, or else other stop means, for example contacts or simple stops. The piston strokes, which determine the volumes of product dosed in the supply chambers, are regulated by acting on the control of the plate drive means.

 According to an advantageous arrangement of the invention, the plate is moved vertically by a worm screw system. Thus, the plate carries two ball bearings, respectively 74A, 74B, which are fixed relative to this plate. Screw rods, respectively 76A, 76B cooperate with these bearings. These screw rods define helical tracks for the bearing balls, so that the rotation

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 synchronized screws consequently displaces plate 68 in translation.

In this case, the screws are rotated by pulleys, respectively 78A, 78B, which they carry respectively. These pulleys are themselves rotated by a belt system 80.

Indeed, as best seen in Figure 5, a servomotor 81 rotates a driving pulley 82, which cooperates with the belt 80 so that the latter drives the driven pulleys 78A and 78B. For example, the pulleys 82, 78A, 78B can be arranged in a triangle, substantially so as to form the vertices of an equilateral triangle. This makes it possible to balance the forces exerted on the belt 80. It can be a single belt arranged so as to form back and forth between the pulleys, or two belts, respectively connected to the pulleys 82 and 78A and pulleys 82 and 78B. An initialization detector 81 'makes it possible to know the initialization position of the servomotor 81.

 To adjust the piston stroke, you can use the engine control electronics.

 Figure 4 is a section in the plane of the plate 68 (perpendicular to the direction of movement of the pistons) and therefore allows a better understanding of the operation of the means for clutching the pistons on this plate. The plate 68 has a first and a second passage, respectively 84A, 84B, through which the piston rods, respectively 35A, 35B pass. In these passages, pads are placed, respectively 86A, 86B, which limit the friction forces. The clutch means are able to retain the piston rods in these passages or, on the contrary, to allow the plate to slide freely relative to these rods.

 More specifically, the first clutch means comprises at least a first spindle secured to the back-and-forth movement of the plate and capable of being moved relative to the latter between a disengaged position and a engaged position in which it cooperates with the piston rod of the first chamber for retaining this rod relative to the plate, and the second clutch means comprises at least a second pin, integral with the back-and-forth movement of the plate and able to be moved by relation to the latter between a disengaged position and a engaged position in which it cooperates

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 with the piston rod of the second chamber to retain this rod relative to the plate.

 By the example shown, as can be seen in FIG. 4, the first clutch means comprises two pins, respectively 87A and 88A, just as the second clutch means comprises two pins, respectively 87B and 88B. The plate includes passages for these pins, formed by bores, respectively 89A and 90A for pins 87A and 88A, and 89B and 90B for pins 87B, 88B.

 The pins are movable in translation in these bores. For their part, the piston rods each have grooves, respectively 91A and 92A for the rod 35A, and 91B and 92B for the rod 35B. On each piston rod, these grooves are parallel. In FIGS. 2 and 4, the rod 35A of the piston 34A is disengaged, and it can be seen that the grooves 91A, 92A are not placed in register with the bores 89A, 90A, which are partially masked by the external periphery of the piston rod. On the other hand, the rod 35B of the piston 34B is engaged, the grooves 91B, 92B being placed in the bores 89B, 90B, so that the pins can be introduced into said bores. The pins cooperate with the grooves of the external periphery of the rod of this piston, to block the latter relative to the plate. For each clutch assembly, the two pins are arranged in a fork with parallel branches and the two grooves of the piston are diametrically opposite.

 In the example shown, the sets of pins, respectively 87A, 88A and 87B, 88B are controlled separately, each being by a jack of its own, respectively 94A and 94B.

These are for example pneumatic cylinders, the movable part of which directly carries the spindle assemblies. Advantageously, position detection means, respectively 95A, 95B are associated with each of the two cylinders to instantly make it possible to know whether the corresponding piston is engaged or not. The cylinders are integral with the plate 68, and are carried by it during its movement.

 The cylinders and the position sensors are shown in Figure 3 for clarity, although they are not normally visible on the section.

 Means are provided so that, when a piston is disengaged from the plate, move this piston relative to said plate.

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 These means allow on the one hand, as seen for the piston 34A of Figure 2, to place the pistons in positions that it is not always possible to reach with a movement operated with the plate.

Thus, Figure 2 shows the piston 34A outside of its cylinder 32A.

On the other hand, they maintain the piston in a given position, when the latter is disengaged from the plate, to make the metering chamber 34A perfectly inactive.

 Finally, when it is desired to re-engage a previously disengaged piston, it is important to correctly wedge its position in order to be able to place the grooves 91A, 92A in the bores 89A, 90A. In the example shown, the means for positioning the pistons independently of the plate are formed by jacks, respectively 96A for the piston 34A and 96B for the piston 34B. These cylinders are not visible in the plane of Figure 2, but they are in Figures 5 and 6. These cylinders are carried by the upper guide plate 60, and their movable parts cooperate with the supports of the pistons, respectively 52A and 52B. In this case, each of the cylinders 96A and 96B may comprise two elementary cylinders, respectively 96'A and 96 "A and 96'B and 96" B to respectively request the displacement of the piston up and down. When a piston is engaged on the plate, the corresponding cylinder 96A or 96B is deactivated, so that the piston can slide freely in relation to it. On the other hand, when the piston is disengaged relative to the plate, the corresponding jack can be activated to maintain its position and to place it in the desired position so that it can be re-engaged.

 As shown in Figures 2 and 3, the outputs SA and SB of the chambers 30A and 30B, as well as the distribution outlet 18, are formed in a body 100. This is for example a part, having cells , respectively 100A and 100B which respectively form the lower portions of the metering cylinders 32A and 33B, this part being fixed to a central body 102, in which the central regions of the chambers are formed.

 The body 100 has a first channel 104A which connects the outlet SA of the chamber 30A to the distribution outlet 18 and a second channel 104B which connects the outlet SB of the chamber 30B to the outlet 18. These channels are also connected to the conduit of purge 19 and the rotary selector 24 is

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 disposed at the intersection of channels 104A, 104B with the distribution outlet 18 and the drain pipe 19.

 Depending on its position, the selector 24 selectively isolates one or other of the channels 104A and 104B from the output 18. It then connects the isolated channel to the purge duct 19.

 The selector 24 is controlled between its two positions by a rotary actuator 106 and the shutter 46 is controlled between its open and closed positions by a rotary actuator 108, synchronized with the movement of the active piston and its plug.

 In fact, the selector 24 and the shutter 46 are in the form of plugs, biased against their respective seats, 24 ′ and 46 ′ by jacks 106 ′, 108 ′ and capable of being moved away from these seats by controlling the same cylinders. When the bushels are thus separated, these bushels and the various conduits of the body 100 can be washed by circulation of a washing solution.

 When washing a chamber 30A or 30B, by introducing a washing solution through the orifices 56'A, 57'A or 56'B, 57'B, the solution can exit through the purge duct 19 to which is connected the chamber considered by the selector 24.

 For washing the entire device, the plugs 24 and 46 are separated from their seats and the washing solution can also be injected through the product inlets EA, EB.

 The space E24, formed at the rear of the plug 24 and isolated from the chambers 30A and 30B when this plug is in abutment against its seat, can also be used for cleaning, thanks to orifices 24'A and 24'B ( only rough) used respectively for feeding and discharging a washing solution.

 The same goes for the space E46 formed at the rear of the plug 46, thanks to the orifices 46'A and 46'B (only sketched).

Claims (14)

CLAIMS 1. Device for dispensing a liquid or pasty product, comprising a first supply chamber (30A) having a product inlet (EA), a product outlet (SA) and means (34A, 40A) for discharging in a clocked fashion determined volumes of product through said outlet, characterized in that it comprises a second supply chamber (30B) also having a product inlet (EB), a product outlet (SB) and means ( 34B, 40B) for delivering in a cadenced manner determined volumes of product through this outlet and in that it comprises a distribution outlet (18) and selection means (24) capable of selectively communicating the product outlet from one of the chambers with said distribution outlet by isolating from this distribution outlet the product outlet from the other chamber. 2. Device according to claim 1, characterized in that the product outlets (SA, SB) from the two chambers (30A, 30B) and the distribution outlet (18) are formed in a body (100) having a first channel ( 104A) connecting the outlet of the first chamber to the distribution outlet and a second channel connecting the outlet of the second chamber to said distribution outlet, the selection means being able to selectively isolate one or the other of said channels from said distribution outlet. 3. Device according to claim 1 or 2, characterized in that, for each chamber (30A, 30B), the means for delivering in a timed manner determined volumes of product comprise a metering cylinder (32A, 32B) forming a region of the chamber next to the product outlet (SA, SB), a metering piston (34A, 34B) movable back and forth in said cylinder, at least one product inlet opening (38A, 38'A, 38B , 38'B) formed in said piston and a shutter member (40A, 40B) capable of releasing or closing said inlet opening. 4. Device according to claim 3, characterized in that the shutter member is a plug (40A, 40B), capable of being moved with the metering piston (34A, 34B) in the reciprocating movement of the latter and to <Desc / Clms Page number 17>  be turned relative to it to release or seal said intake opening (38A, 38'A, 38B, 38'B). 5. Device according to claim 4, characterized in that, for each metering piston (34A, 34B), the plug (40A, 40B) and the metering piston respectively have a first and a second contact surface (44A, 44'A ) and are able to occupy, with respect to each other, a working position in which said surfaces are in substantially sealed contact and a washing position in which these surfaces are separated. 6. Device according to claim 5, characterized in that, for each metering piston (34A, 34B), the plug (40A, 40B) is disposed inside the piston and has a hollow rod (41A, 41B) itself even disposed inside the rod (35A, 35B) of the piston, the plug rod cavity having an inlet (56'A, 56'B) located at one end of the rod external to the piston and a communication ( 57A, 57B) located at the opposite end, while the rod (35A, 35B) of the piston has an orifice (57'A, 57'B) located outside the supply chamber. 7. Device according to any one of claims 3 to 6, characterized in that it comprises a movable plate (68), means (81, 80,74A, 74B, 76A, 76B, 78A, 78B) for displacing said platinum back and forth and clutch means (87A, 88A, 87B, 88B, 91A, 92A, 91B, 92B) to selectively return the piston (34A) of the first supply chamber (30A) or the piston ( 34B) of the second supply chamber (30B) integral with the movement of the plate. 8. Device according to claim 7, characterized in that the plate has a first and a second passage (84A, 84B) through which pass respectively the rod (41A) of the piston (34A) of the first supply chamber (30A) and the rod (41B) of the piston (34B) of the second supply chamber (30B), a first clutch means (87A, 88A) able to be moved relative to the plate (68) between a disengaged position in which it allows relative sliding between the plate (68) and the piston (34A) of the first chamber and a engaged position in which it prevents this sliding, as well as a second clutch means (87B, 88B) capable of being moved relative to the plate between a disengaged position in which it allows relative sliding between the plate (68) and the piston (34B) of the second <Desc / Clms Page number 18>  chamber and a clutched position in which it prevents this sliding. 9. Device according to claim 8, characterized in that the first clutch means comprises at least a first pin (87A, 88A), integral with the reciprocating movement of the plate and capable of being displaced relative to the latter between a disengaged position and a engaged position in which it cooperates with the rod (41A) of the piston (34A) of the first chamber (30A) to retain said rod relative to the plate (68), and in that the second clutch means comprises at least a second pin (87B, 88B), integral with the reciprocating movement of the plate and able to be moved relative to the latter between a disengaged position and a engaged position in which it cooperates with the rod (41B) of the piston (34B) of the second chamber (30B) to retain this rod relative to the plate (68). 10. Device according to claim 9, characterized in that the means for controlling the movements of each spindle comprise a jack (94A, 94B) integral with the plate (68). 11. Device according to any one of claims 7 to 10, characterized in that it comprises means (96A, 96B) for, when a piston (34A, 34B) is disengaged from the plate (68), move this piston with respect to said plate.  12. Device according to any one of claims 7 to 11, characterized in that the means for moving the plate back and forth comprise a worm system (76A, 76B).  13. Device according to any one of claims 1 to 12, characterized in that it comprises a shutter (46), disposed at the dispensing outlet (18) and able to be opened and closed in a clocked manner.  14. Device according to claim 13, characterized in that it comprises a purge duct (19), capable of being selectively connected to the outlet (SA, SB) of each distribution chamber (30A, 30B).