Fluid product dispenser

Abstract

A fluid dispenser having a reservoir (R) containing fluid (P) and air (A), the reservoir (R) forming an assembly opening (11); a fluid dispenser cannula (12) in communication with the reservoir (R); and an actuator member (2) engaged in the assembly opening (11), for supplying the dispenser cannula (13) with fluid (P). The actuator member (2) has a deformable membrane (23) that defines an outside face (231) forming a pusher (24), and an inside face (232) that is in contact with the air (A) of the reservoir (R), when the dispenser cannula (12) is in contact with the fluid (P) of the reservoir (R).

Claims

1. An assembly method for assembling a dispenser, wherein the dispenser comprises: a reservoir containing fluid and air, the reservoir forming an assembly opening; a fluid dispenser cannula in communication with the reservoir, the dispenser cannula forming a dispenser end; and an actuator member engaged in the assembly opening, for supplying the dispenser cannula with fluid coming from the reservoir; wherein the actuator member comprises a deformable membrane that defines an outside face forming a pusher, and an inside face that is in contact with the air of the reservoir, when the dispenser cannula is in contact with the fluid of the reservoir; wherein the actuator member includes an assembly sleeve that is inserted in sealed manner in the assembly opening of the reservoir; wherein the assembly sleeve performs one sealed axial stroke in the assembly opening of the reservoir in order to reach its final sealed assembled position, the sealed axial stroke defining a stroke volume Vc; and wherein the deformable membrane is movable between a rest position and a fully depressed position so as to define, between these two positions, an actuation volume Va that is greater than, or preferably substantially equal to, the stroke volume Vc of the assembly sleeve; the method comprising the following steps: a) filling the reservoir with fluid via its assembly opening in the absence of the actuator member; b) engaging the actuator member in the assembly opening of the reservoir, the deformable membrane being held in its fully depressed position when the assembly sleeve comes into sealed contact with the assembly opening of the reservoir; and c) while the assembly sleeve is in sealed contact with the assembly opening of the reservoir, releasing the deformable membrane, which thus returns into its rest position.

2. The assembly method according to claim 1, wherein the dispenser comprises a protective cap that is provided with closure means for closing the dispenser end of the dispenser cannula in sealed manner.

3. The assembly method according to claim 2, wherein the reservoir and the dispenser cannula are made in the form of a single-piece body that is advantageously made of a transparent material.

4. The assembly method according to claim 1, comprising the following successive steps: b1) deforming the deformable membrane into its fully depressed position; b2) engaging the actuator member in the assembly opening of the reservoir until the assembly sleeve comes into sealed contact with the assembly opening of the reservoir; c1) releasing the deformable membrane so that it returns into its rest position; c2) moving the actuator member in the assembly opening of the reservoir, so as to cause the assembly sleeve to slide in sealed manner in the assembly opening until it reaches its final sealed assembled position.

5. The assembly method according to claim 1, comprising the following successive steps: b1) deforming the deformable membrane into its fully depressed position; b2) engaging the actuator member in the assembly opening of the reservoir until the assembly sleeve comes into sealed contact with the assembly opening of the reservoir; c12) progressively releasing the deformable membrane so that it returns into its rest position as the assembly sleeve slides in sealed manner in the assembly opening, the rest position and the final sealed assembled position advantageously being reached substantially simultaneously.

6. The assembly method according to claim 5, wherein the axial force necessary to deform the deformable membrane from its rest position into its final sealed assembled position is less than the friction forces between the assembly sleeve and the assembly opening during sealed sliding for reaching the final sealed assembled position.

7. The assembly method according to claim 1, wherein the dispenser end of the dispenser cannula is closed in sealed manner.

8. The assembly method according to claim 1, wherein the dispenser is a dropper dispenser.

9. The assembly method according to claim 1, wherein the dispenser end is configured to form a drop of fluid that separates from the dispenser end by gravity.

Description

(1) In the figures: FIG. 1 is a vertically cut-away perspective view through a fluid dispenser of the invention, shown at rest; FIG. 2 is a view similar to the view in FIG. 1, shown during dispensing; FIG. 3 is a much larger-scale view of the actuator member engaged in the assembly opening of the reservoir; FIG. 4 is an even larger-scale view of a detail D of FIG. 3; and FIG. 5 is a flowchart showing the various steps of assembling the dispenser, with possible variants.

(2) Reference is made firstly to FIGS. 1 and 2 in order to describe in detail the structure and the operation of a fluid dispenser of the invention, which is in the form of a dropper dispenser. However, the invention is not limited exclusively to dropper dispensers, and may apply to other types of dispenser.

(3) The dispenser of the invention comprises three component elements, namely a main body 1, an actuator member 2, and a protective cap 3. In some circumstances, the cap 3 may be optional.

(4) The main body 1 may be made of any appropriate material, such as a plastics material that is translucent or transparent. It may also be made of glass. The main body 1 may be made as a single piece, i.e. made as a single-piece part, or it may be made by assembling together a plurality of separate parts. It is also possible to envisage making the main body 1 by using over-molding or bi-injection methods.

(5) The main body 1 includes a cylinder 10 that, in this embodiment, presents a section that is constant, in particular circular. At its top end, the cylinder 10 includes an assembly opening 11 in which the actuator member 2 is engaged, as described below. At its opposite end, the main body 1 forms a dispenser cannula 12 that internally defines an outlet duct 14. The dispenser cannula 12 forms a dispenser end 13 that is configured in such a manner as to be suitable for forming a drop of fluid that separates from the dispenser end 13 by gravity, as can be seen in FIG. 2. The fluid accumulates at the outlet of the dispenser end 13, as can be seen in FIG. 2, until the drop is large enough for its own weight to cause it to separate from the dispenser end 13 and fall in the form of a drop. The particular configuration of the dispenser end 13 means, amongst other things, that the dispenser can be referred to as a dropper dispenser.

(6) Between the cylinder 10 and the dispenser cannula 12, the main body 1 forms a shoulder 15 that is extended by a neck 16 that is connected to the cannula 12 via a frustoconical interconnection section 17. The particular shape of the main body 1 between the cylinder 10 and the cannula 12 is not critical to the present invention, such that other embodiments are possible.

(7) The actuator member 2 may be made as a single piece by injection-molding a relatively flexible plastics material, such as thermoplastic polymer. The actuator member 2 comprises an assembly sleeve 21 of shape that is generally cylindrical, a projecting collar 22 that extends outwards at the top end of the assembly sleeve 21, and a deformable membrane 23 that extends inside the assembly sleeve 21, e.g. in the proximity of its bottom end. The deformable nature of the membrane 23 can be obtained by a wall thickness that is smaller than the wall thickness of the sleeve 21 or of the collar 22. In FIG. 1, the actuator member 2 is in its rest state, and it should be observed that the deformable membrane 23 is upwardly dome-shaped, i.e. convex towards the collar 22. In other words, the deformable membrane 23 is concave towards the inside of the cylinder 10. In its assembled state, the actuator member 2 is engaged inside the assembly opening 11 of the main body 1, with the assembly sleeve 21 engaged inside the opening 11, and the collar 22 bearing against the top annular edge of the assembly opening 11. The deformable membrane 23 is in its rest position, with is convex shape facing outwards.

(8) When assembled on the main body 1, as shown in FIG. 1, the protective cap 3 covers the dispenser cannula 12 and advantageously closes the outlet duct 14 in sealed manner. To do this, the protective cap 3 may define a small dish 33 in which the dispenser end 13 is engaged in sealed manner. By way of example, the dish 33 may be made of a flexible material that is connected to the remainder of the cap 3 by overmolding or by bi-injection. In order to ensure that the cap 3 is held in place on the main body 1, it may for example be force-fitted around the neck 16 in such a manner as to come into abutment bearing against the shoulder 15. It is also possible to provide releasable snap-fastening between the neck 16 and the cap 3.

(9) The dispenser of the invention thus defines a fluid reservoir R that extends from the deformable membrane 23 to the inlet of the dispenser cannula 12. The reservoir R is mainly defined by the cylinder 10: it also extends into the neck 16 and into the frustoconical interconnection section 17. The fluid P stored in the reservoir R thus communicates directly with the dispenser duct 14. In a variant, it is possible to provide a two-way valve at the inlet of the dispenser cannula 12 so as to increase head loss between the reservoir R and the dispenser duct 14. It should also be observed that the reservoir R also contains air A above the meniscus M of the fluid P. In other words, the air A is situated between the deformable membrane 23 and the meniscus M, inside the cylinder 10, when the dispenser cannula 12 points downwards, as shown in FIGS. 1 and 2. The fluid P is thus in direct communication with the dispenser duct 14.

(10) In the invention, the deformable membrane 23 defines an outside face 231 and an inside face 232, as can be seen in FIG. 3. The outside face 231 forms a pusher 24 on which the user can press by means of a finger or a thumb, so as to move the deformable membrane 23 towards the inside of the cylinder 10. In FIG. 1, the dispenser is provided with its protective cap 3, and pressing on the pusher 24 has no effect other than to compress the air A held captive inside the reservoir R. The fluid P is indeed subjected to pressure, but since its dispenser duct 14 is plugged by the dish 33, no fluid is dispensed. In contrast, when the cap 3 is removed as shown in FIG. 2, pressing on the pusher 24 in the direction of arrow F1, causes the membrane 23 to deform until it reaches a fully depressed position, as shown in FIG. 2, and as shown in FIG. 3 by dashed lines. The air A held captive in the reservoir is thus put under pressure and the resulting force F2 is exerted on the fluid P at its meniscus M. In response, fluid P is driven through the dispenser duct 14 and accumulates at the dispenser end 13 in the form of a drop that increases in size until it separates from the cannula 12 on reaching a critical size. This is shown in FIG. 2.

(11) Given that the air A is compressible, the pressing force F1 is not transmitted directly to the fluid P: on the contrary, it is damped by the air A, so that the delivered force F2 is less than the pressing force F1. In this way, sudden dispensing of fluid is avoided, which prevents a train of successive drops being formed.

(12) FIG. 3 shows the actuator member 2 that is engaged inside the assembly opening 11 of the main body 1. The assembly sleeve 21 is engaged with the inner wall of the assembly opening 11, and the projecting collar 22 comes to bear against the top annular edge of the opening 11. The deformable membrane 23 is drawn with continuous lines in its rest position, and with dashed lines in its fully depressed position. An actuation volume Va is thus defined between the two extreme positions. The volume Va is represented by the hatched zone in FIG. 3. In other words, when the user presses on the pusher 24 so as to depress the deformable wall 23 until it reaches its fully depressed position, a quantity of fluid P that corresponds substantially to the actuation volume Va is dispensed through the dispenser cannula 12. In reality, the quantity of fluid dispensed is a little less than the actuation volume Va, because of the compressibility of the air A held captive in the reservoir R.

(13) In order to reach its final assembled position, the actuator member 2 is engaged in the assembly opening 1, and then it is depressed so as to travel along one sealed axial stroke S, as shown in FIG. 4. By way of example, the outer wall of the assembly sleeve 21 may come into contact with a sealing rib 111 that is formed inside the assembly opening 11. Once engaged in the opening 11, the sleeve 21 comes into sealed contact with the sealing rib 111, and then, from this moment, the sleeve 21 slides in sealed manner against the sealing rib 111, over an axial height that corresponds to the sealed axial stroke S, so as to arrive finally in its final assembled position in which the collar 22 comes to bear against the top annular edge of the opening 11. It is also possible to provide snap-fastening for the sleeve 21 around or below the rib 111. The sealed axial stroke S defines a stroke volume Vc, that is merely the product of the stroke S multiplied by the inside diameter of the opening 11.

(14) In the invention, the actuation volume Va is greater than the stroke volume Vc. Preferably, the actuation volume Va is greater than the stroke volume Vc by a very small amount, or it is substantially equal to said stroke volume Vc. Below, it can be seen how advantage can be taken of this relationship between the two volumes Va and Vc in order to optimize assembly of the dispenser.

(15) Specifically, it is preferable for the fluid P stored inside the reservoir R to be at atmospheric pressure when the user removes the protective cap 3 for the first time, so as to avoid any fluid being accidentally dispensed. However, given that the actuator member 2 is inserted into the assembly opening 1 by travelling along one sealed axial stroke of volume Vc, the air A situated above the meniscus M, after filling the reservoir with fluid, is normally put under pressure. Putting the air under pressure in this way could possibly cause the membrane 23 to deform and to remain stretched in this way for a relatively long period of storage.

(16) In order to avoid any increase in pressure of the fluid inside the reservoir, or any stretching deformation of the membrane 23, the present invention defines a particular assembly method comprising the following successive steps: a) filling the reservoir R with fluid P via its assembly opening 11 in the absence of the actuator member 2; b) engaging the actuator member 2 in the assembly opening 11 of the reservoir R, the deformable membrane 23 being held in its fully depressed position when the assembly sleeve 21 comes into sealed contact with the assembly opening 11 of the reservoir R; and c) while the assembly sleeve 21 is in sealed contact with the assembly opening 11 of the reservoir R, releasing the deformable membrane 23, which thus returns into its rest position.

(17) Step b) above may be sub-divided into two sub-steps: b1) deforming the deformable membrane 23 into its fully depressed position; and b2) engaging the actuator member 2 in the assembly opening 11 of the reservoir R until the assembly sleeve 21 comes into sealed contact with the assembly opening 11 of the reservoir R.

(18) Step c) above may be sub-divided into two sub-steps that may be performed in any order: c1) releasing the deformable membrane 23 so that it returns into its rest position; and c2) moving the actuator member 2 in the assembly opening 11 of the reservoir R, so as to cause the assembly sleeve 21 to slide in sealed manner in the assembly opening 11 until it reaches its final sealed assembled position. Intervention of the two sub-steps c1 and c2 is shown in FIG. 5.

(19) In a variant, step c) may comprise a single step c12) during which the deformable membrane 23 is released progressively so that it returns into its rest position while the assembly sleeve 21 slides in sealed manner in the assembly opening 11, the rest position and the final sealed assembled position advantageously being reached substantially simultaneously. In this situation, no increased pressure is generated in the reservoir R, since the volumes Va and Vc vary simultaneously and in opposite directions.

(20) It is thus possible to choose between the following sub-steps: c1, then c2, creating increased pressure momentarily; c2, then c1, creating suction momentarily; or c12, creating no variation in pressure.

(21) It is also advantageous for the axial force necessary to deform the deformable membrane 23 from its rest position into its final sealed assembled position to be less than the friction forces between the assembly sleeve 21 and the assembly opening 11 during sealed sliding for reaching the final sealed assembled position. Thus, it is possible firstly to press directly on the membrane in order to bring it into its fully depressed position, and then secondly to cause the sleeve 21 to slide in the opening 11

(22) As mentioned above, the reservoir is not filled completely, such that there is air in the reservoir when the actuator member is engaged in the assembly opening of the reservoir, thereby making it possible to compress and to expand the air held captive in the reservoir during steps b) and c).

(23) In all variations, and in particular with sub-steps c1 and c2, it is preferable, or even necessary, for the protective cap 3 to be in place, so as to close the dispenser duct 14. In this way, it is possible to avoid any outflow of fluid or any inflow of outside air. This prior or initial step of putting the cap 3 in place is represented by the block i) in the FIG. 5 flowchart. The cap 3 could be replaced by any other closure means while performing the method of assembly.

(24) The invention provides a very simple dispenser that is instinctive to use and very accurate. Furthermore, the method of assembly guarantees that the dispenser as delivered to the user is at atmospheric pressure.