EP1673596A2

EP1673596A2 - Device for the dosing of at least two products

Info

Publication number: EP1673596A2
Application number: EP04786384A
Authority: EP
Inventors: Vincent Jean-Marie Tournerie
Original assignee: Axiali
Current assignee: Axiali
Priority date: 2003-08-22
Filing date: 2004-08-20
Publication date: 2006-06-28
Also published as: FR2859019A1; FR2859019B1; WO2005022092A2; WO2005022092A3

Abstract

The invention relates to a device for the dosing of at least two products, e.g. at least one powdered product or a mixture of powdered products, known as an abrasive, and a liquid. The inventive device comprises at least one first tank (16) which can contain at least one first product (12), at least one first piston (20) which can release said at least one first product (12) from the first tank (16), and a cylinder (32) in which a second piston (22) moves in translation such as to define two chambers, one of which forms a second tank (18) which can contain a second product (14). According to the invention, a fluid is introduced into the other chamber (34) such as to ensure the translational movement of the second piston (22) in order to release the second product (14) from the second tank (18). Moreover, the pistons (20, 22) are kinemtaically linked so that the quantities of the mixed products (12, 14) are proportional. The invention is characterised in that the device also comprises means for filling the two chambers on either side of the second piston (22) with the second product (14).

Description

DEVICE FOR DOSING AT LEAST TWO PRODUCTS

The present invention relates to a device for dosing at least two products. This device is more particularly intended for hydrogumming devices, for mixing at least one pulverulent product or a mixture of pulverulent products with a liquid. However, it may be suitable for other applications.

Hydrogumming devices are used to gently clean or strip any surface, including walls. This technique has the advantages of not damaging fragile surfaces unlike sanding and of not being chemical.

According to this technique, three components are mixed, namely air, a powder or a mixture of powders subsequently called abrasive and a liquid, preferably water, this liquid making it possible to avoid the formation of a cloud. dust or splashing powder. To obtain an effective treatment of surfaces, it is advisable to plan a precise dosage of these three constituents. According to the prior art, the abrasive chosen according to the work to be carried out and generally stored in a bag is emptied into a tank in which it is mixed with water. The tank is then pressurized by means of a water pump. This pump also makes it possible to adjust the flow rate of the water introduced into the tank and in fact the adjustment of the abrasive / water mixture ejected from the tank and mixed with air, the water being incompressible. Furthermore, the water introduced into the tank preferably at the bottom makes it possible to avoid clogging of the abrasive. This technique is not satisfactory because the abrasive and water percentages are not stable over time. Indeed, due to the technique used, the percentage of abrasive is necessarily higher at the start and decreases gradually. In addition, once mixed with water, the abrasive must be used. Thus, at the end of a site, the abrasive / water mixture remaining in the tank is discarded, resulting in waste and a problem of effluent rejection. Also, the present invention aims to overcome the drawbacks of the prior art by proposing a device for metering at least two products, in particular at least one pulverulent product or a mixture of pulverulent products, called abrasive, with a liquid, ensuring a precise and stable dosing over time and reducing wastage of products. To this end, the subject of the invention is a device for metering at least two products, in particular at least one pulverulent product or a mixture of pulverulent products called abrasive with a liquid, said device comprising at least one first reservoir capable of containing at at least a first product, at least a first piston capable of ejecting said at least one first product outside said at least one first reservoir, as well as a cylinder in which a second piston translates delimiting two chambers, one of which constitutes a second tank capable of containing a second product, a fluid being introduced into the other chamber in order to ensure the translation of the second piston to eject the second product outside the second tank, the pistons being kinematically linked so that the quantities of products mixed are proportional, characterized in that it comprises means for filling the second product with the two chambers arranged es on either side of the second piston. This arrangement makes it possible to obtain percentages of products that are constant over time and precise. On the other hand, the unused products are not mixed which helps to limit waste. Finally, the use of the same product to mix the first product and to translate the second piston makes it possible to save a third product and all the elements necessary for its management. Other characteristics and advantages will emerge from the description which follows of the invention, description given by way of example only, with reference to the appended drawings in which:

FIG. 1 is a diagram illustrating the operating principle of the metering device,

- the figure is a section of the device of the invention according to a first variant,

FIG. 2B is a section of the device according to another variant,

FIG. 3 is a section through the upper part of the device, illustrating in detail the injection means,

FIG. 4 is an elevation view of a ring belonging to the device,

FIG. 5 is a section illustrating an alternative embodiment of the piston dedicated to the abrasive,

FIG. 6 is a perspective view illustrating the cover of the device, and

- Figure 7 is a section of the cover of Figure 6.

In the various figures, there is shown at 10 a device for metering at least one pulverulent product or a mixture of pulverulent products with a liquid, more particularly suitable for a hydrogumming apparatus.

By powdery product is meant any product in the form of powders, fines, aggregates or the like. For the remainder of the description, the pulverulent product or the mixture of pulverulent products is called abrasive 12.

Those skilled in the art are able to choose the abrasive, in particular its nature and its particle size, depending on the application.

In known manner, the abrasive 12 is mixed with a liquid 14, preferably water. One of its functions is to prevent the formation of a dust cloud when the abrasive is projected.

The device 10 of the invention comprises a first reservoir 16 capable of containing the abrasive 12, a second reservoir 18 capable of containing the liquid 14, each reservoir 16 and 18 comprising a piston 20, 22 capable of respectively ejecting the abrasive 12 outside the first reservoir via an orifice 24 and the liquid 14 outside the second reservoir 18 via an orifice 26, the orifices 24 and 26 being connected to a conduit 28 for conveying the abrasive / liquid mixture by means of injection means 30. In known manner, the conveying conduit 28 is connected to an ejection nozzle not shown, in which the abrasive / liquid mixture is mixed with air. According to an important characteristic of the invention, the pistons 20 and 22 are kinematically linked so that the quantities of abrasive 12 and of mixed liquid are proportional. This arrangement makes it possible to obtain constant and precise percentages of abrasive and liquid. Furthermore, it should be noted that the unused abrasive and the liquid are not mixed, which contributes to limiting the wastage of abrasive.

The ratio between the quantity of abrasive and of liquid depends on the ratio between the sections of the pistons 20 and 22.

According to another characteristic of the invention, the piston 22 dedicated to the liquid 14 translates into a cylinder 32 closed at each of its ends and delimits two chambers, one of which, according to FIGS. 1 and 2, the upper chamber, corresponds to the reservoir liquid 18, a fluid being introduced into the second chamber 34 in order to ensure the translation of the piston 22. Advantageously, the fluid introduced into the chamber 34 is identical to the liquid 14, namely generally water. This arrangement makes it possible to use the same product, in this case water, to mix with the abrasive and to push the piston 22 thus contributing not to use a third fluid and to simplify the management of the products.

Preferably, the device comprises means for adjusting the flow rate or the pressure of the fluid introduced into the chamber 34, thus making it possible to adjust the flow rate or the pressure of the abrasive / liquid mixture. Advantageously, the reservoir 16 containing the abrasive is in the form of a cartridge 36 with at a first end, a wall 38 in which is formed an opening corresponding to the orifice 24, closed before use by a cover, and at the other end a wall 40 capable of sliding inside the cartridge, pushed by the piston 20.

This arrangement facilitates the use of the device. So when the operator decides to change the abrasive, he just needs to change the cartridge. If the cartridge is not completely empty it can use it later.

According to another characteristic of the invention, illustrated by FIG. 3, the injection means 30 have a T shape, the foot corresponding to a duct 42 for supplying abrasive 12, one of the branches of the head of the T corresponding to a conduit 44 for supplying liquid and the other branch corresponding to conduit 28 for conveying the abrasive / liquid mixture. This arrangement contributes to improving the mixture of the abrasive and the water by avoiding the formation of lumps of abrasive. Preferably, the liquid supply conduit 44 has a reduced passage section, making it possible to increase the speed of ejection of the liquid, which contributes to improving the bursting of the abrasive and to preventing the formation of lumps.

According to another characteristic of the invention, the device comprises means for filling the second reservoir 18 with liquid. According to a preferred embodiment and illustrated by FIGS. 2A and 2B, the filling means comprise a nozzle 46 disposed at the level of the second piston 22 capable of occupying two states, a first so-called passing state in which it allows the transfer of fluid between the two chambers arranged on either side of the piston 22, and a second so-called blocked state in which it prohibits the transfer of fluid between the two chambers.

According to another characteristic of the invention, the device comprises back-pressure means 48 controlling the flow of liquid ejected from the reservoir 18 so to increase the pressure in the chambers arranged on either side of the piston 22 during operation. According to a preferred embodiment and illustrated in FIG. 3, the back pressure means 48 are arranged at the level of the injection means 30 and comprise a throttle 50 at the level of the liquid supply duct 44, also used as a nozzle . Thus, when the pressure in the chambers arranged on either side of the piston 22 exceeds a certain threshold, the nozzle 46 is in the blocked state while in the opposite case it is in the on state.

According to an embodiment illustrated in Figures 2 and 4, the nozzle 46 comprises a ring 52 disposed at the periphery of the piston 22 whose outer diameter is substantially identical to the inner diameter of the cylinder 32, said ring 52 comprising at least a cutout forming an opening 54, preferably grooves, making it possible to communicate the chambers arranged on either side of the piston 22, as well as a deformable element preferably in the form of an O-ring 56 capable of occupying two states , a first non-deformed state at rest in which it does not cover the grooves 54 and a second deformed state in which it covers the grooves 54 and thus seals between the two chambers arranged on either side of the piston 22. Preferably, when it is deformed, the seal 56 is in contact with the cylinder 32 so as to ensure a better seal between the piston 22 and said cylinder 32.

According to a preferred embodiment, the piston 22 comprises a body 58 in the form of a disc extended by a hollow rod 60 connecting said body 58 to the first piston 20, a flange 62 in the form of a disc parallel to the body 58, said flange being extended by a rod 64 sliding inside the hollow rod 60 as well as an element 66 deformable by crushing ensuring at the periphery of the body 58 a sealed connection between said body 58 and the flange 62. Thus, when the pressure of on either side of piston 22 exceeds a certain threshold, the flange 62 tends to approach the body 58 which causes the deformation by crushing of the element 66 whose outer diameter increases causing the deformation of the seal 56. Advantageously, an exhaust duct 68 is provided at the first piston 20 in order to communicate the inside of the hollow rod 60 with the outside. Thus, in operation, when the pressures in the chambers arranged on either side of the piston exceed a certain threshold, the element 66 crushed between the body 58 and the flange 62 is deformed and causes the joint 56 to be deformed. nozzle is in the blocked state.

When the user decides to change the cartridge and reload the reservoir 18, the chamber 34 is no longer supplied with liquid and the pressures inside the chambers are such that the element 66 returns to its initial undeformed shape. The seal 56 is no longer deformed and the nozzle 46 is in the on state. According to another characteristic, the device comprises return means 70, tending to have the pistons 20 and 22 in the high state in the high position. According to an embodiment illustrated in FIG. 2A, the return means 70 are of the mechanical type and are in the form of a coil spring for example.

According to another embodiment illustrated in FIG. 2B, the return means are of the pneumatic type, a rod 71, preferably hollow and connected to the bottom of the chamber 34, being capable of sliding in the hollow rod 64, a small space being formed between the outer diameter of the rod 71 and the inner diameter of the rod 64, sealing means being provided between the exterior of the rod 71 and the interior of the hollow rod 64 at the lower end of said rod 64. Preferably, the inside of rod 71 communicates with the outside or a source of pressurized air, crossing the bottom of the chamber 34, as shown diagrammatically in FIG. 2B. Advantageously, regulation means 72 make it possible to control the exhaust and / or the intake into direction of the inside of the rod 71 in order to regulate the pneumatic return means.

So when the user decides to change the cartridge, he removes the cartridge in place. In the absence of a bottom pressed against the upper surface of the piston 20, the return means 70 cause the pistons 20 and 22 to translate upwards. At this instant, the nozzle 46 is in the on state. When reintroducing a cartridge, the user presses the bottom of said cartridge against the upper face of the piston 20 and exerts a downward force causing the translation downwards of the pistons. The nozzle 46 being in the on state, the reservoir 18 is filled with liquid. When the lower end of the side wall of the cartridge is in place, it is noted that the piston 20 is always pressed against the bottom of the cartridge. Thus, the abrasive / liquid mixture is produced from the start. This arrangement is more particularly advantageous when the operator introduces a cartridge already started. As soon as the cartridge is put in place, the pistons 20 and 22 eject abrasive 12 and liquid 14 respectively. According to another characteristic, the piston 20 includes a deformable bead 73 at the periphery ensuring better sealing between said piston 20 and the internal side wall of the cartridge, in particular when the abrasive is stored in a flexible envelope 74 inside the cartridge. Thus, when the piston 20 translates to eject the abrasive 12, the bead 73 is inflated. According to one embodiment, the interior of the bead 73 communicates with the zone delimited by the body 58, the flange 62 and the wall 66 of the second piston 22. Thus, in operation, the pressure in the chambers tends to bring the flange 62 closer together. of the body 58 causing an increase in pressure and the deformation of the bead 73.

In Figures 6 and 7, there is shown closing means 76 for holding a cartridge and facilitating its change. In the lower part, the cartridge is held by the first piston 20. In the upper part, the closing means 76 comprise a first fixed plate 78 comprising an opening 80, preferably of diameter adapted to the diameter of the cartridge. The closing means 76 also comprise a movable cover 82, articulated relative to the plate 78 by means of a hinge 84, said cover being capable of occupying two positions, a first position in which it allows the introduction of a cartridge. and a second position, pressed against the plate 78, in which it holds the cartridge. Preferably, the cover 82 comprises a conduit 86 opening out on either side of said cover, capable of communicating at a first end with the interior of the cartridge and at the other end with the injection means 30 attached to the cover 82.

Advantageously, the closing means 76 also comprise locking means 88 making it possible to maintain the cover 82 in the second position. In this case, the fixed plate 78 comprises on each side of the wings 90 at the level of which two holes 92 are formed in which a locking pin 94 can translate. In addition, the cover 82 also comprises on each side, two wings 96, capable of coming from either side of the wings 90 of the plate 78, said wings 96 each having a cutout 98 capable of receiving the ends of the axis. 94 lock. Thus, to lock the cover 82, it suffices to translate the locking pin 94 so that the latter comes to be housed in the cutouts 98. To unlock the cover 82, it is sufficient to translate in the opposite direction the axis 94 locking mechanism so that it no longer holds the cover 82.

According to another characteristic of the invention, the means 88 for locking the cover 82 are coupled to means 100 for controlling the flow of the liquid. To this end, the means 100 for controlling the flow rate of the liquid comprise an axis of control 102 whose rotation causes the opening or closing of a valve controlling the flow of liquid. In addition, the holes 92 receiving the locking axis 94 have an L-shape, the horizontal branch 104 allowing the translation of said axis 94 to ensure the locking and unlocking of the cover 82 and the vertical branch 106 serving to block the axis. In this way preventing said translation, return means 108 tending to immobilize the control axis 94 at the vertical branch 106.

The control pin 102 comprises a cam 110 mounted eccentrically on said pin 102 whose side wall 112 is such that when the locking pin 94 immobilizes the cover 82, the rotation of the control pin 102 is possible and when the the locking pin 94 is immobilized at the vertical branch 106, the rotation of the control pin 102 is impossible. Preferably, the edges of the wings 96 of the cover 82 have a shape 114 suitable for moving the locking pin 94 from the vertical branch 106 towards the horizontal branch 104.

The coupling of the means 88 for locking the cover 82 and the means 100 for controlling the liquid flow rate makes it possible to avoid inadvertent opening of the valve for the liquid when loading the cartridge. According to a preferred embodiment and illustrated by FIGS. 6 and 7, the opening 80 comprises means for holding the upper end of a cartridge comprising a first fixed jaw 116 and a second movable jaw 118 capable of moving in direction of the first jaw so as to clamp the upper end of a cartridge. The variable spacing between the two jaws 116 and 118 makes it possible to adjust the device to different diameters of cartridges. In addition, one of the two jaws comprises at its upper surface a stop 120, preferably of semi-spherical shape, slightly protruding with respect to the inner surface 122 of the jaw, capable of to immobilize a cartridge in vertical translation. The device may include several stops 120 arranged indifferently on the two jaws 116 and 118. In the closed position, the cover plate 82 abuts against the jaws 116 and 118 or a slight clearance is provided between said jaws and said plate. In addition, the plate 82 includes a cutout 124 allowing the stop 120 to pass.

Of course, the invention is obviously not limited to the embodiment shown and described above, but on the contrary covers all variants, in particular with regard to the dimensions and materials of the various elements as well as the nature of the liquid. and abrasive.

Alternatively, one could consider mixing several abrasives stored in several tanks or cartridges with a liquid. In this case, the device of the invention comprises a single cylinder 32 or second reservoir 18 with a single second piston 22 connected ci ematically to several first pistons 20 sliding in several cartridges or first reservoirs 16. Finally, one could consider the use of such a metering device in other applications for which it is necessary to accurately dose a pair of products, for example two liquids, a liquid and a fatty product, a liquid and a pulverulent product, a pasty product and a powdery product, etc.

Claims

1. Device for metering at least two products, in particular at least one pulverulent product or a mixture of pulverulent products called an abrasive with a liquid, said device comprising at least one first reservoir (16) capable of containing at least one first product ( 12), at least a first piston (20) capable of ejecting said at least one first product (12) outside said at least one first reservoir (16), as well as a cylinder (32) in which a second translates piston (22) delimiting two chambers, one of which constitutes a second reservoir (18) capable of containing a second product (14), a fluid being introduced into the other chamber (34) in order to ensure the translation of the second piston ( 22) for ejecting the second product (14) outside the second tank (18), the pistons (20, 22) being kinematically linked so that the quantities of products (12,14) mixed are proportional, characterized in that it includes filling means as a second product (14) of the two chambers arranged on either side of the second piston (22).

2. Device according to claim 1, characterized in that it comprises means for filling the second tank (18) comprising a nozzle (46) disposed at the level of the second piston (22) capable of occupying two states, a first state said passer-by in which it authorizes communication between the two chambers arranged on either side of the piston (22) and a second so-called blocked state in which it prohibits transfer between the two chambers.

3. Device according to claim 1 or 2, characterized in that the reservoir (16) containing the first product (12), in particular the abrasive, is in the form of a cartridge (36) with at one end a wall (40) capable of sliding inside the cartridge, pushed by the first piston (20).

4. Device according to any one of the preceding claims, characterized in that it comprises injection means (30) allowing the mixing of the products (12, 14), with a T-shape, the foot corresponding to a conduit (42) for supplying the first product (12), one of the branches of the head of the T corresponding to a conduit (44) for supplying the second product (14) and the other branch corresponding to a conduit (28 ) dedicated to mixing products.

5. Device according to claim 4, characterized in that the conduit (44) for supplying the second product has a reduced passage section, making it possible to increase the speed of ejection of said second product.

6. Device according to any one of claims 2 to 5, characterized in that it comprises means (48) against pressure controlling the flow of second product (14) ejected from the second tank (18) in order to increase the pressure in the chambers arranged on either side of the piston (22) during operation and to control the change of state of the nozzle (46).

7. Device according to any one of claims 1 to 6, characterized in that it comprises return means (70) tending to have the pistons (20, 22) in the high position in the high position.

8. device according to any one of claims 1 to 7, characterized in that the piston (20) comprises on the periphery a deformable bead (73) ensuring a better seal between said piston (20) and the internal side wall of the first reservoir (16).

9. Device according to any one of claims 1 to 8, characterized in that it comprises means (76) for closing with a cover (82) movable capable of occupying two positions, a first position in which it allows the introduction of the first reservoir and a second position in which it maintains said reservoir, locking means (88) being provided to maintain the cover (82) in the second position.

10. Device according to claim 9, characterized in that the means (88) for locking the cover (82) are coupled to means (100) for controlling the flow rate of the second product.