Fluid product reservoir

Abstract

The invention relates to a fluid product reservoir (R) comprising: - a cylindrical shaft (R1) defining a length along an axis of revolution (X), an inner wall (R11) and an outer wall (R12), - a fluid product outlet (R4), - a piston (P) slidingly and sealingly engaged with the inner wall (R11) of the cylindrical shaft (R1), so as to be able to perform a stroke, - fluid product (Pf) in the cylindrical shaft (R1) on one side of the piston (P), and - air (A) in the cylindrical shaft (R1) on the other side of the piston (P), characterised in that it further comprises an RFID tag (E), in particular of the NFC type, applied to the outer wall (R12) of the cylindrical shaft (R1).

Description

[0001] Fluid product tank

[0002] The present invention relates to a fluid product reservoir comprising a cylindrical barrel defining a length along an axis of revolution X, an inner wall and an outer wall. The reservoir also comprises a fluid product outlet and a piston engaged in sealed sliding with the inner wall of the cylindrical barrel, so as to be able to perform a stroke. The fluid product is present in the cylindrical barrel on one side of the piston, while air is present in the cylindrical barrel on the other side of the piston. The preferred field of application of the invention is that of cosmetics and pharmacy, without forgetting food, care products, drugstore, etc.

[0003] When the piston is a follower piston, its movement is generated by a depression in the fluid product. In general, fluid product is extracted from the cylindrical barrel, for example by a pump, which generates a depression, which will suck the follower pin.

[0004] When the piston is a pusher piston, its movement puts the fluid product under pressure in the cylindrical barrel, so that it is forced out through the fluid product outlet.

[0005] In both cases, the movement of the piston and the decrease in the volume of fluid in the cylindrical barrel are closely linked. It can also be said that the positioning of the piston gives an indication of the filling state of the cylindrical barrel with fluid.

[0006] When the cylindrical barrel is transparent or translucent and the cylindrical barrel is visible, the user can determine the filling status by locating the position of the piston in the cylindrical barrel.

[0007] On the other hand, when the cylindrical barrel is not visible or not transparent, the user cannot see the piston and therefore has no direct indication of the filling status of the cylindrical barrel.

[0008] The present invention aims to give the most precise indirect indication possible of the filling state of the cylindrical barrel, particularly in the case where the cylindrical barrel is not visible or not transparent.

[0009] To do this, the present invention proposes that the tank further comprises an RFID tag, advantageously of the NFC type, applied to the external wall of the cylindrical barrel. The RFID tag comprises, in addition to a conventional chip and antenna, a capacitive level sensor for measuring the level of the fluid product in the cylindrical barrel. In addition, the piston is electrically conductive, so as to influence the capacitive level sensor. The piston may be coated with a metal layer, for example in the form of a deposit of a conductive film on the piston. Alternatively, the piston may be made from a plastic material loaded with metal particles or provided with one or more metal parts. A plastic material may for example be overmolded onto a metal part. Preferably, the metal part is separable from the plastic piston for recycling purposes.In fact, various techniques can be used to obtain a piston, follower or pusher, with electrical conductivity, capable of improving detection by the capacitive level sensor through the wall of the cylindrical barrel. Ideally, the capacitive level sensor should react mainly to the movement of the conductive piston, and to a lesser extent to the fluid product and air.

[0010] According to another aspect of the invention, the capacitive level sensor comprises a measuring electrode which can extend along the axis of revolution X. Advantageously, the measuring electrode extends over the majority of the length of the cylindrical barrel and preferably over the entire stroke of the piston.

[0011] According to another interesting characteristic, the measuring electrode defines an area that can vary along the axis of revolution X. The area can vary linearly or in stages. Advantageously, the area decreases with the decrease in fluid product in the cylindrical barrel. In other words, the area is maximum when the tank is full and minimum when it is empty. Thus, the influence of the fluid product on the capacitive level sensor decreases in concert with that of the piston, so that a multiplied effect is obtained, both downwards and upwards. When the tank is full, the capacitive level sensor is strongly stimulated by the fluid product which is at its maximum volume and by the piston which is located at the level of the maximum area of ​​the measuring electrode.And when the tank is empty, the capacitive level sensor is weakly stimulated by the fluid product which is at its minimum volume and by the piston which is located at the level of the minimum area of ​​the measuring electrode.

[0012] The invention also defines a method for manufacturing a fluid product reservoir, comprising the following successive steps: a- providing a fluid product reservoir comprising a cylindrical barrel and a piston engaged in sealed sliding in the cylindrical barrel, said piston being advantageously conductive, b- providing an RFID tag (for example NFC) comprising a chip, an antenna and a capacitive level sensor without a measuring electrode, but provided with two terminals, c- applying the RFID tag to the cylindrical barrel, d- producing the measuring electrode so as to connect it to the two terminals of the capacitive level sensor.

[0013] This manufacturing process thus divides the development of the RFID (NFC) tag into two distinct stages, namely a first stage of manufacturing a standard tag, but without a measuring electrode, and a second stage of manufacturing the measuring electrode, which is specific to each tank, and more particularly to each piston stroke. The first stage can be carried out by an RFID (NFC) tag manufacturer and the second stage can be carried out by the tank manufacturer. The tag can comprise a flat and flexible substrate having a self-adhesive underside. The chip (or microprocessor), the antenna and the capacitive sensor (without a measuring electrode) are mounted on the substrate, which can comprise a dimensionable extension, on which the measuring electrode will be produced. This extension can be cut to fit the tank and its piston.Conversely, the substrate can be small in size and in this case the electrode is made directly on the outer wall of the cylindrical barrel or on another suitable substrate, which is applied to the outer wall of the cylindrical barrel next to the substrate of the RFID (NFC) tag.

[0014] Without departing from the scope of the invention, the production of the specific measuring electrode can be carried out before the application of the label to the cylindrical barrel.

[0015] The present invention also defines a fluid product dispenser comprising a dispensing head and a fluid product reservoir as defined above.

[0016] The spirit of the invention lies in using an RFID tag, particularly NFC, to measure the filling status of a piston tank. The capacitive technology and the conductive piston provide very advantageous results. The two-step manufacturing process allows the tag to be adapted to all types of piston tanks.

[0017] The invention will now be described in more detail, with reference to the attached drawings, giving, as non-limiting examples, two embodiments of the invention.

[0018] In the figures:

[0019] Figure 1 is a vertical cross-sectional view through a fluid dispenser comprising a reservoir according to the invention, with a smartphone next to the dispenser,

[0020] Figure 2a is a plan view of the tank with an NFC tag and a measuring electrode according to a first embodiment of the invention,

[0021] Figure 2b is an enlarged view of the NFC tag of Figure 2a,

[0022] Figure 3a is a plan view of the tank with an NFC tag and a measuring electrode according to a second embodiment of the invention, and

[0023] Figure 3b is an enlarged partial view of the NFC tag of Figure 3a.

[0024] In Figure 1, we see a fluid dispenser of the invention and a smartphone S integrating NFC (Near Field Communication) technology, that is to say a short-range, high-frequency wireless communication technology, allowing the exchange of information between peripherals up to a distance of approximately 10 cm in the general case. This smartphone S can therefore communicate with the dispenser of the invention, which is equipped with an NFC tag, designated E, which comprises a substrate E0, a chip E1, an antenna E2 and a capacitive level sensor E3, which is provided with a measuring electrode M. The smartphone S can therefore excite the chip E1 of the NFC tag and retrieve information from the capacitive level sensor E3 to process and display it, so that the user can know what the filling status of the fluid tank R is.

[0025] More generally, within the framework of the invention, any RFID tag can be implemented, of which NFC is a very widespread variation, particularly in smartphones.

[0026] In more detail, the fluid dispenser of the invention comprises a dispensing head T, comprising a pump K, a push button B and optionally a protective cover C. The inlet of the pump K is connected to a fluid reservoir R, which contains fluid Pf. The head T is also connected to an outer shell S, which surrounds the reservoir R. The outer shell S forms an open bottom, through which the reservoir R can be introduced and connected to the pump K. Thus, the reservoir once empty can be replaced by a new full reservoir. The outer shell S can be opaque, transparent or translucent.

[0027] By pressing the push button B, the pump K is actuated, resulting in the dispensing of a dose of fluid product Pf through a dispensing orifice O formed at the push button B. When the pressure is released on the push button B, the pump K draws a dose of fluid product Pf from the reservoir R. This is a completely classic design and operation for a dispenser in the field of cosmetics, pharmacy or even food.

[0028] The fluid product reservoir R is the heart of the invention. It conventionally comprises a cylindrical barrel R1 which defines an internal wall R11 and an external wall R12. The barrel R1 is widely open at its lower end and extends upwards, forming a shoulder R2 and a neck R3, which internally defines a fluid product outlet R4. The shoulder R2 is optional, so that the neck R3 can extend in the extension of the barrel R1. It can be noted that the barrel R1, with its optional shoulder R2 and its neck R3, has a symmetry of revolution around an axis of revolution X.

[0029] The reservoir R also comprises a piston P, which is engaged in sealed sliding with the internal wall R11 of the cylindrical barrel R1, so as to be able to perform an axial stroke. In this embodiment, the piston P is a follower piston, which moves in response to a depression of the fluid product present in the barrel R1, when the push button B of the pump K is released. Without departing from the scope of the invention, the piston may be a pusher piston, for example biased by a spring or a pressurized gas. In this case, the dispensing head may be limited to a valve or a simple outlet flap.

[0030] The piston P here comprises two cylindrical lips P1, which come into sealed sliding contact with the internal wall R11 of the barrel R1. The two lips P1 are mounted on a plate P2.

[0031] Thus, when the reservoir R contains fluid product Pf, the piston P constitutes a moving bottom, which is in contact with the fluid product Pf. On the other side, the piston is in contact with the air A.

[0032] According to the invention, the piston P may have electrical conductivity. The piston P may, for example, be coated with a metallic layer. It may also be made from a plastic material loaded with metallic particles. In the embodiment of the figures, the piston P is provided with a metallic part P3 associated with the plate P2, preferably out of contact with the fluid product Pf. The metallic part P3 may thus be fixed under the plate P2. The plate P2 may be overmolded onto the metal part P3. Preferably, the metallic part P3 is separable from the plate P2 for recycling purposes. It is also possible to place a metallic part P3 on both faces of the plate P2 to increase the conductive mass. A piston P made entirely or almost entirely of metal is also conceivable. A metal piston may be coated with a protective layer compatible with the fluid product Pf. The metal used may be steel, copper, Zamac, aluminum, etc.

[0033] According to the invention, the tank R, and more particularly its barrel R1, is provided or equipped with an NFC label, which is designated as a whole by E. The NFC label is affixed to the external wall R12 of the barrel R1, i.e. out of contact with the fluid product Pf, which comes into contact with the internal wall R11 of the barrel R1. Thus, the label E is separated from the fluid product Pf by the wall thickness of the barrel R1.

[0034] As already mentioned, the NFC tag, designated E, comprises a substrate E0, on which a chip E1 (or microprocessor), an antenna E2 and a capacitive level sensor E3 are mounted. The substrate E0 is located below the piston P in its position corresponding to the filled state of the tank, i.e. in its lowest position.

[0035] We can now refer to Figures 2a and 2b, which show the label E in more detail. Typically, the antenna E2 extends around the chip E1 with a coil configuration. The capacitive level sensor E3 is mounted on the substrate E0 next to the chip E1 and its antenna E2. The capacitive level sensor E3 operates as an open capacitor with two conductive plates E31 and E32 separated by a dielectric E30. Between these two plates E31 and E32 an electric field is formed. If a material with a dielectric constant higher than that of air enters the electric field, the capacitance of the field increases according to the dielectric constant of this material. The electronics measures this increase in capacitance, the generated signal is evaluated during subsequent signal processing.

[0036] The first plate E31 of the capacitive level sensor E3 is connected to the chip E1 by a connection E13 and acts as a grounded ground electrode. The second plate E32 is connected by a connection E33 to a first terminal EM1 , while the chip E1 is connected by a connection E12 to a second terminal EM2. A measuring electrode M, which extends along the X axis over the major part of the barrel R1 , is connected to the terminals EM1 and EM2. The axial extent of the measuring electrode M corresponds substantially to the axial stroke of the piston P in the barrel R1 .

[0037] In this first embodiment, the measuring electrode M comprises two lobes M1 and M2, both having the shape of a right triangle. The lobes M1 and M2 form electrically conductive areas. They are arranged in mirror symmetry with the opposite hypotenuses. They are separated by an axial notch M3, which is closed at its upper end. Each lobe M1, M2 comprises a short horizontal base arranged adjacent to the substrate E0 and a vertical height whose upper ends are connected by a bridge M4. The upper tips of the two triangular lobes M1 and M2 are thus electrically connected. The lobe M1 is electrically connected to the terminal EM1, while the lobe M2 is electrically connected to the terminal EM2.

[0038] It can be said that the measuring electrode M has a triangular-shaped area, surface area or surface, which decreases as the fluid product Pf is extracted from the reservoir R. In other words, the conductive piston P sweeps the measuring electrode M in such a way that the area of ​​the measuring electrode M located at the axial level of the conductive piston P decreases.

[0039] Thus, the conductive piston P, when in the low position, is located axially at the widest part of the measuring electrode M, close to the horizontal bases of the two right triangles. The influence of the conductive piston P on the capacitive level sensor E3 is then maximum, especially since the fluid product Pf is present behind all or almost all of the measuring electrode M.

[0040] As the conductive piston P moves upwards towards the outlet R4, its influence decreases, since the width of the two lobes M1 and M2 decreases. And when the conductive piston P reaches the end of its stroke at the top of the barrel R1, its influence is minimal. In addition, the quantity of fluid product Pf is also minimal, so the capacity of the capacitive level sensor E3 is then at its minimum.

[0041] The capacity measured by the capacitive level sensor E3 is therefore strongly decreasing, since the influence of the piston P and the fluid product Pf decrease together. Ideally, the influence of the piston P should be considerably greater than that of the fluid product Pf, so that the piston P alone gives an accurate indication of the filling state of the tank R.

[0042] The measuring electrode M can be made directly on the external wall R12 by connecting to the terminals EM1 and EM2. Alternatively, the measuring electrode M can be made on another substrate, similar or identical to the substrate E0, which is applied to the external wall R12 by connecting to the terminals EM1 and EM2.

[0043] Referring now to Figures 3a and 3b, a second embodiment is seen with label E' and a measuring electrode M'.

[0044] The label E' is much more extensive than the label E, since the measuring electrode M' is formed on the substrate E0', which extends over the entire or almost the entire height of the barrel R1. The label E' can be supplied to the tank manufacturer with a large substrate E0', which can then be resized by cutting to fit the tank and the measuring electrode M'. The tank manufacturer can then make the measuring electrode M' on the resized substrate E0', before or after the substrate E0' is affixed to the external wall R12 of the barrel R1.

[0045] At the bottom of the substrate E0', there is a chip E1, an antenna E2 and a capacitive level sensor E3, as in the first embodiment. Two terminals EM1' and EM2' are also formed on the substrate E0'. The measuring electrode M' is connected to these two terminals EM1' and EM2'.

[0046] While the lobes M1 and M2 of the measuring electrode M form the massive conductive areas, the measuring electrode M' is formed with a continuous sinuous conductive track, i.e. with a conductive line describing meanders. More precisely, the conductive track or line, of greater or lesser thickness, forms loops Ma, Mb, Mc, Md and Me, which extend in an increasing manner along the X axis. There are two small loops Ma located on the outside and a large loop Me located axially centrally: the loops Mb, Mc and Md being of increasing axial size and arranged between the small loops Ma and the large loop Me. All the loops Ma, Mb, Mc, Md and Me are joined so as to form the continuous conductive line or track, which is connected to the terminals EM1' and EM2'.

[0047] Thus, the conductive piston P, when in the low position, is located axially at the widest part of the measuring electrode M', where all the loops Ma, Mb, Mc, Md and Me are formed. The piston P crosses 16 conductive line or track segments. The influence of the conductive piston P on the capacitive level sensor E3 is then maximum, especially since the fluid product Pf is present behind all or almost all of the measuring electrode M.

[0048] As the conductive piston P moves upwards towards the outlet R4, its influence decreases, since it crosses fewer and fewer conductive line or track segments. And when the conductive piston P reaches the end of its travel at the top of the barrel R1, its influence is minimal, since it only crosses the large yaw Me. In addition, the quantity of fluid product Pf is also minimal, so the capacity of the capacitive level sensor E3 is then at its minimum.

[0049] The capacitance measured by the capacitive level sensor E3 is therefore strongly decreasing, as in the first embodiment, with the difference that it is continuous in the first embodiment and notched or incremented in the second embodiment.

[0050] The invention provides a tank whose conductive piston is used to improve the measurement of its filling state, thanks to a particular measuring electrode configuration. The processing and display of data from the capacitive level sensor and the chip are advantageously carried out using a smartphone that integrates NFC technology, which is a form of RFID.

Claims

Claims 1. Fluid product tank (R) comprising: - a cylindrical barrel (R1) defining a length along an axis of revolution (X), an internal wall (R11) and an external wall (R12), - a fluid product outlet (R4), - a piston (P) engaged in sealed sliding with the internal wall (R11) of the cylindrical barrel (R1), so as to be able to perform a stroke, - fluid product (Pf) in the cylindrical barrel (R1) on one side of the piston (P), - air (A) in the cylindrical barrel (R1) on the other side of the piston (P), - an RFID tag (E; E'), advantageously of the NFC type, applied to the external wall (R12) of the cylindrical barrel (R1), the RFID tag (E; E') comprising, in addition to a chip (E1) and an antenna (E2), a capacitive level sensor (E3) for measuring the level of the fluid product (Pf) in the cylindrical barrel (R1), characterized in that the piston (P) is electrically conductive, so as to influence the capacitive level sensor (E3).

2. Fluid product reservoir according to claim 1, in which the capacitive level sensor (E3) comprises a measuring electrode (M; M') which extends along the axis of revolution X.

3. Fluid product reservoir according to claim 2, in which the measuring electrode (M; M') extends over the majority of the length of the cylindrical barrel (R1) and advantageously over the entire stroke of the piston (P).

4. Fluid product reservoir according to any one of claims 2 and 3, in which the measuring electrode (M; M') defines an area which varies along the axis of revolution X.

5. Fluid product reservoir according to claim 4, in which the area varies linearly or in stages.

6. Fluid product reservoir according to claim 4 or 5, in which the area decreases with the decrease in fluid product (Pf) in the cylindrical barrel (R1).

7. Method for manufacturing a fluid product reservoir (R), comprising the following steps: a) providing a fluid product reservoir (R) comprising a cylindrical barrel (R1) and a piston (P) engaged in sealed sliding in the cylindrical barrel (R1), b) providing an RFID tag (E; E'), in particular of the NFC type, comprising a chip (E1), an antenna (E2) and a capacitive level sensor (E3) without a measuring electrode (M; M'), but provided with two terminals (EM1, EM2; EM1', EM2'), c) applying the RFID tag (E; E') to the cylindrical barrel (R1), d) producing the measuring electrode (M; M') so as to connect it to the two terminals (EM1, EM2; EM1', EM2') of the capacitive level sensor (E3).

8. Fluid product dispenser comprising a dispensing head (T) and a fluid product reservoir (R) according to any one of claims 1 to 6. * * *

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