WO2019193275A1 - Fluid-product dispensing head - Google Patents

Abstract

The invention relates to a dispensing head (T) comprising a nozzle (2) having a spray wall (21), the head (T) incorporating an air chamber (C) for purging the nozzle (2) after each fluid-product dispensing phase.

Description

 Fluid dispensing head

The present invention relates to a fluid dispensing head intended to be associated with a dispensing member such as a pump or a valve. The head may be in the form of a pusher and define a bearing surface on which the user can exert a thrust force to actuate the dispensing member. The dispensing head may be integrated with, or mounted on, the dispenser member. This kind of fluid dispensing head is frequently used in the fields of perfumery, cosmetics or pharmacy.

 A conventional dispensing head, for example of the push-type, comprises:

 a connection sleeve intended to be connected to an outlet of a dispensing member, such as a pump,

 an inlet well in the extension of the connecting sleeve,

 an axial mounting housing in which a pin extends, defining a side wall and a front wall, and

 - A bucket-shaped nozzle comprising a substantially cylindrical wall, one end of which is closed by a spray wall forming a spray orifice, the nozzle being mounted along an axis X in the axial mounting housing with its cylindrical wall engaged around the spindle and its spray wall in axial abutment against the front wall of the spindle.

 In FR2903328A1, there are described several embodiments of a nozzle comprising a spray wall pierced with a plurality of spray holes having a diameter of the order of 1 to 100 pm.

Such a spray wall would generate a spray whose droplet size would be relatively homogeneous.

The document WO2015194962 describes several embodiments of a nozzle comprising a spray wall pierced with several holes. and one or more filters arranged upstream of the spray wall.

 A problem with this type of micro-hole nozzle is that it sometimes clogs, so that the spray gradually deteriorates to become even impossible. Initially, it was thought that the clogging or clogging of the nozzle was due to fine particles being suspended in the fluid or from the manufacture, assembly or operation of the dispensing member (pump). It is only after several series of tests that the cause of this plugging or clogging of the nozzle has been identified: it seems to come from the drying or the strong increase of viscosity of the fluid product at the level of the jet itself. Thus, solid or pasty residues would form in the nozzle and clog the spray wall and / or filter (s), which would lead to alteration, or even stop, the spray.

 To solve this problem of clogging or clogging of any nozzle, and more particularly those of the micro-hole type, the present invention proposes a fluid dispensing head having a connection sleeve intended to be connected to a rod of actuating a dispensing member, such as a pump, the fluid product dispensing head comprising a bearing surface for moving the actuating rod axially back and forth and thus actuate the dispensing member, the fluid dispensing head also comprising a spray wall pierced with a network of spray holes through which the pressurized fluid product passes to be sprayed into fine droplets, the spray holes having a diameter of 1 to 100 μm, the fluid dispensing head defining a fluid supply path connecting the sleeve connection to the spray wall, the assembly further comprising:

an air pump having an air chamber of variable volume, such that the volume of the air chamber decreases when pressure is exerted on the bearing surface and increases when the pressure is released on the bearing surface, an air passage that connects the air chamber to the fluid supply path, and

 a differential sequencing valve which closes the passage of air when the pressure of the fluid product in the fluid supply path is greater than the pressure of the air in the air chamber, and which clears the air passage; when the fluid pressure in the fluid supply path is lower than the pressure of the air in the air chamber, so that the pressurized air from the air chamber passes into the path supply fluid and through the network of spray holes just after the fluid.

 Thus, the air chamber generates a flow of pressurized air that expels fluid from a portion of the feed path through the spray wall, ultimately leaving the fluid supply path empty, at least in its portion from the outlet of the air passage in the feed path to the spray wall. We can talk about a purge air product fluid. There is no fluid that enters or leaves the air chamber, only air. It must be noted that the air pump and the differential sequencing valve are formed by the dispensing head, and not by the dispensing member.

 Advantageously, the spray holes have a diameter of the order of 5 to 30 μm, and preferably of the order of 10 to 15 μm. All the holes of the spray wall may have the same diameter, or different diameters, for example divided into two or three sets of holes of different diameters, with the holes of the same series having an identical diameter. The spray wall may be flat or curved, convex and / or concave. The holes can be perpendicular or inclined.

 According to one embodiment, the air pump may comprise two sealingly engaged parts, namely a drum part and a piston part. We are here in a classic pump configuration.

Advantageously, the dispensing head further comprises a skirt which extends around the connecting sleeve, the skirt being connected to the connection sleeve by an upper annular flange, so as to defining between them an annular space, the barrel portion being formed by the connecting sleeve, the skirt and the upper annular flange. On the other hand, the piston portion may comprise two pistons respectively in sliding sealing engagement with the connecting sleeve and the skirt. The air passage can pass through the upper annular flange.

 According to one embodiment, the dispensing head may further comprise a mounting housing, in which is engaged a nozzle, the spray wall being secured to the nozzle. Advantageously, the differential sequencing valve is engaged in the mounting housing upstream of the nozzle. The inner wall of the housing can form a valve seat for the differential valve. The air passage may connect the air chamber to the mounting housing through the upper annular flange.

 According to another embodiment, the piston portion is formed by the bearing surface, made in the form of a deformable membrane of the air chamber.

 According to an advantageous embodiment, the dispensing head further comprises at least one filter upstream of the spray wall. The filter may be in the form of a filter plate having filter holes that are larger than the spray holes, but smaller in diameter than the spray holes. The filter may also be in the form of a filter block forming a network of open cavities. A same nozzle may include both one or more filter plates and one or more filter blocks.

The spirit of the invention lies in purging the multi-hole nozzle of the fluid that it contains after the spraying phase. The air chamber creates a flow of air under pressure just after the spraying phase, which has the effect of blowing the fluid contained in the nozzle. Thus, the nozzle is certainly empty of any fluid, so there is no risk of clogging or clogging by drying, formation of solid residues or increase in viscosity. The invention will now be further described with reference to the accompanying drawings, giving by way of non-limiting examples, two embodiments of the invention.

 In the figures:

 FIG. 1 is an exploded perspective view of a distributor incorporating a dispensing head according to a first embodiment of the invention,

 FIG. 2 is an enlarged sectional view at rest of the dispensing head of FIG. 1,

 FIG. 3 is a view of the dispensing assembly of FIG. 2 in the intermediate actuating position,

 FIG. 4 is a view of the distribution assembly of FIG. 2 in the end position depressed,

 FIG. 5 is an enlarged cross-sectional view through the nozzle of the dispensing head of FIGS. 2 to 4,

 FIG. 6 is a front view of the nozzle spray wall of FIG. 5, and

 Figures 7 and 8 are cross-sectional views through a dispensing head according to a second embodiment of the invention.

 In Figure 1, there can be seen a dispenser comprising a fluid reservoir R, a dispensing member D, which can be a pump, a dispensing head T and a mounting piece P.

 The dispensing member D is fixed on an opening of the tank R by means of a fixing ring F. The dispensing member D comprises an actuating rod D1 which is axially movable back and forth to the against a return spring (not shown). The dispensing member D may be conventional: it did not participate in the invention.

In FIGS. 2, 3 and 4, it can be seen that the mounting piece P is fixed on the tank R or on the fixing ring F. The mounting piece P comprises for this purpose a fixing ring P4 which can come into taken, for example, around the fixing ring F. The part P also comprises an internal piston P1 and an external piston P2 which are concentric. The inner piston P1 forms an inner lip P1 1 and the outer piston P2 forms an outer lip P21. An annular space P3 is defined between the two pistons P1 and P2. Piece P is also traversed by a central opening PO for the passage of the actuating rod D1 of the dispensing member D, but it does not participate in its operation.

 The dispensing head T comprises a head body 1, a nozzle 2, a differential sequencing valve 3 and a plug 4.

 The head T is preferably one-piece and comprises a connecting sleeve 11 receiving the actuating rod D1, a skirt 12 and a mounting housing 16 receiving the nozzle 2, the valve 3 and the plug 4. The skirt 12 surrounds the sleeve 1 1 concentrically. The skirt 12 is connected to the sleeve 1 1 by an upper annular flange 14, so as to define between them an annular space 13. The mounting housing 16 extends transversely and passes through the head body from side to side. It comprises a wide opening 161 at one end and a conical bearing 162 at the other end. The sleeve 1 1 is connected to the housing 16 by a window 15 and the annular space 13 is connected to the housing 16 by an air passage 17 which passes through the annular flange 14.

 Optionally, the head body 1 can be engaged in a dressing capsule 5 comprising upper bearing surface 51 for a finger and a lateral casing 52 forming a lateral opening 53 for the nozzle 2. In the absence of capsule 5, the bearing surface is formed by the upper surface of the head body 1.

The nozzle 2 is received in the conical bearing 162 of the housing 16. The nozzle 2 is introduced into the housing 16 by the wide opening 161. Alternatively, a detent is also conceivable. As can be seen in Figure 5, the nozzle 2 comprises a nozzle body 20 which serves to support a spray wall 21 pierced with holes 22. The spray wall 21 is fixed to the nozzle body 20 by any means, such as overmoulding, bi-injection, snapping, crimping, swaging, force mounting, etc. The spray wall 21 may be a one-piece monobloc plate, an assembly of several parts or a multilayer product, for example laminated. It can be made of metal, plastic, ceramic, glass or a combination of these. More generally, any material that can be pierced with small holes or holes is usable. The spray wall 21 may be flat or curved. The thickness of the spray wall 21 at the level where the holes 22 are formed is of the order of 10 to 100 μm. The number of holes 22 is of the order of 20 to 500. The diameter of the holes 22 can range from 1 to 100 μm, and advantageously from 5 to 30 μm. Holes of 10 to 15 μm are suitable for spraying perfume. The holes may be parallel or divergent. The diameter of the spray wall 21 at the level where the holes 22 are formed is of the order of 0.5 to 5 mm.

 Advantageously, the nozzle 2 also comprises two filters F1 and F2 arranged upstream of the spray wall 21. The filter F1 is a plate substantially similar to the spray wall 21 with filter holes FO which are advantageously more numerous than the holes 21, but which advantageously have a diameter smaller than that of the spray holes 22. It may also be noted that the diameter of the filter plate F1 is greater than that of the spray wall 21. Its thickness may be substantially the same than that of spray wall 21, or even slightly higher.

 The filter F2 is also mounted upstream of the filter F1 by defining between them a second intermediate space E2. The filter F2 is in the form of a block of porous material, advantageously rigid, such as Porex ®, which forms a network of open cavities, whose average pore size may be of the order of 7 to 100 microns .

The differential sequencing valve 3 is integrally formed by the dispensing head T. It is mounted in the mounting housing 16 just behind the nozzle 2. The valve may optionally serve or assist in keeping the nozzle in place in the housing 16. The valve 3 is in the form of a hollow cuff with an annular valve lip 31 which comes into selective sealing against the inner wall 163 of the housing 16, which serves as a valve seat. This inner wall 163 can separate the sleeve 1 1 from the housing 16: the window 15 passing through this internal wall 163. At rest, as shown in FIG. 2, the valve 3 blocks the air passage 17. On the other hand, the window 15 communicates with the nozzle 2 through the hollow interior of the valve 3. In other words, the valve 3 has no influence on the flow path of the fluid.

 The plug 4 is inserted in the housing 16 just behind the valve 3. The plug 4 has a sealing function, but it can also be used to hold the valve 3 and nozzle 2 in place in the housing 16. It can be said that the plug 4 closes the wide opening 161 of the housing 16, so as to force the fluid to flow through the valve 3 and the nozzle 2.

 The mounting piece P, although fixedly mounted on the tank R or on the fixing ring F, is functionally part of the head T, as they together form the air pump. It can thus be said that the air pump is entirely formed by the head T (integrating the part P).

 In Figure 2, the dispenser is at rest. The actuating rod D1 is extended to the maximum, under the action of the return spring. The mounting piece P is then positioned away from the dispensing head T. the pistons P1 and P2 are separated from the sleeve 11 and the skirt 12. The two spaces P3 and 13 face each other, but are open on the outside . The valve 3 is closed: the air passage 17 is closed. On the other hand, the actuating rod D1 is connected to the nozzle 2 through the window 15 and the valve 3.

In FIG. 3, the head T has been moved towards the workpiece P, so that the internal piston P1 is now sealingly engaged around the sleeve 1 1 and the external piston P2 is in leaktight sliding engagement in the skirt 12. two annular spaces P3 and 13 are now joined and isolated from the outside: they then together define an air chamber C of an air pump formed between the head 1 and the mounting piece P. As the head T is moved to the P room, the pressure rises in the air chamber C, but the air can not escape through the passage air 17 because it is closed by the valve 3, which will remain closed as the pressure of the fluid that passes through the valve 3 is greater than that of the air in the air chamber C. In fact, the setting The pressure of the air chamber C is concomitant with the distribution of fluid product, since the head T is depressed. For a conventional pump, the pressure of the fluid product is of the order of 4 to 6 bar and for a valve, the initial pressure is of the order of 10 to 12 bar. The fluid product exits the actuating rod D1 and passes through the window 15 to arrive in the housing 16. More specifically, the fluid under pressure passes between the plug 4 and the valve 3, thus pressing the lip 31 on its seat 163. The flow of the fluid product is indicated by the arrow line L in FIG. 3. It is therefore sufficient that the pressure in the air chamber C does not exceed 3 bars to ensure that the valve 3 remains closed throughout the phase. fluid dispensing system. The fluid and the air do not mix during the distribution phase. The aim is that the air remains in its chamber C until all of the fluid is dispensed, hence the designation of the valve 3, which is subjected to the pressures of the fluid and the air, so guarantee an appropriate sequence: first the fluid and then the air.

 In Figure 4, it is precisely in the configuration where the head T is pressed to the maximum. The fluid product has been dispensed, so that the pressure in the valve 3 has dropped below that prevailing in the air chamber C. Therefore, the lip 31 of the valve 3 will come off and the air passage 17 can then communicate with the housing 16. The pressurized air will then pass through the valve 3 and the nozzle 2, purging them of their fluid content. The path of the air is indicated by the arrow line A in FIG. 4. It should be noted that this flush of air occurs without the head T moving. The air volume of the air chamber C is greater than the cumulative volumes of the valve 3 and the nozzle 2.

The air under pressure is released very quickly: the opening time of the valve 3 being of the order of a few hundredths or thousandths of a second. This rapid flow of air can be described as a "blow gun", making it possible to empty the dispensing head T of its fluid product downstream of the valve 3. Fluid product distribution and airflow are consecutive in time, with no intermediate dead time. The user will not even notice the air gun at the end of fluid dispensing.

 Then, the user releases his pressure on the head T which returns to its rest position of FIG.

 Figures 7 and 8 illustrate a second embodiment, wherein the air pump is integrated with the dispensing head T '. This head T 'comprises a head body 1' which forms a sleeve 1 'and a fluid product duct 15' which opens into a mounting housing 16 'in which a nozzle 2 is received, for example by interlocking force, with or without snapping or harpooning. The head T 'also comprises a dome 4' mounted on the head body 1 ', so as to form between them an air chamber C'. More specifically, the flexible dome 4 'comprises an anchoring edge 42 which is held on the body 1' by a trim ring 5 '. This anchoring edge 42 surrounds a flexible membrane 40 defining a bearing surface 41 for the dispensing head T '. The membrane 40 comprises an annular reinforcement and sealing flange 43 and an air inlet orifice 44, advantageously located in the center of the membrane.

 The air chamber C 'communicates with the housing 16' through an air passage 31 ', which is selectively closed by a differential sequencing valve 3', which may be in the form of a deformable flexible blade having a lip 31 '.

 At rest, as shown in Figure 7, the valve 3 'is closed: its lip 31' sealingly rests against the annular flange 43, which serves as a valve seat. The air chamber C 'has a maximum volume and communicates with the outside through the orifice 44.

A user can press the membrane 40 by plugging the orifice 44. The air contained in the air chamber C 'will go up in pressure, as long as the valve 3' remains closed, that is to say as long as the fluid product is distributed, as in the first embodiment of Figures 1 to 4. As soon as the pressure of the fluid in the housing 16 'drops below that of the air in the air chamber C', the valve 3 'opens and pressurized air crosses the passage 31 ', reaches the housing 16' and then passes through the nozzle 2. As in the previous embodiment, the nozzle is thus purged of its fluid product. When the user releases his support on the membrane 40, outside air enters the air chamber C 'through the orifice 44.

 The present invention thus relies on purging a nozzle by means of an air blower which is generated just after dispensing the fluid. The air is pressurized when the pump is actuated or the valve, which does not involve any additional gestures. The user is not even aware of the pressurization of an air chamber and the blower subsequently generated. This blower according to the invention can be implemented on any fluid dispenser head, but is particularly advantageous for multiple micro-hole nozzles (20 to 500 holes of 1 to 100 microns), advantageously equipped with one or more filters. This avoids any clogging problem. The dispensing head can be mounted on any standard pump or valve, since it incorporates the air pump and differential sequencing valve.

Claims

claims 1 fluid dispensing head (T; T ') having a connecting sleeve (1 1; 1 T) intended to be connected to an actuating rod (D1) of a dispensing member (D), such as a pump, the fluid dispensing head (T; T ') comprising a bearing surface (51; 41) for moving the actuating rod (D1) axially back and forth and thereby actuating the dispensing member (D), the fluid dispensing head (T; T ') also comprising a spray wall (21) pierced with a network of spray holes (22) through which the fluid under pressure passes in order to be sprayed into fine droplets, the spray holes (22) having a diameter of the order of 1 to 100 μm, the fluid dispensing head (T; T ') defining a feed path (L L ') fluid product connecting the connection sleeve (1 1; 1 1') to the wall of pulveri sation (21),  characterized in that it further comprises:  an air pump having an air chamber (C; C ') of variable volume, such that the volume of the air chamber (C; C') decreases when pressure is exerted on the surface of the air chamber; support (51; 41) and increases when releasing the pressure on the bearing surface (51; 41),  - an air passage (17; 3T) which connects the air chamber (C; C ') to the supply path (L; L') fluid product, and a differential sequencing valve (3; 3 ') which closes the air passage (17; 3T) when the pressure of the fluid product in the feed path (L; L') of fluid product is greater than the pressure; air in the air chamber (C; C '), and which releases the air passage (17; 3T) when the pressure of the fluid product in the supply path (L; L') fluid product is less than the pressure of the air in the air chamber (C; C '), so that the pressurized air from the chamber to air (C; C ') passes into the feed path (L; U) into fluid and through the network of spray holes (22) just after the fluid. 2. Dispensing head according to claim 1, wherein the spray holes (22) have a diameter of the order of 1 to 100 μm, advantageously of the order of 5 to 30 μm, and preferably of order of 10 to 15 pm. 3. Dispensing head according to claim 1 or 2, wherein the air pump comprises two parts engaged one inside the other with sliding, namely a portion of barrel (1 1, 12, 14) and a piston portion (P). 4. Dispensing head according to claim 3, wherein the dispensing head (T) further comprising a skirt (12) which extends around the connecting sleeve (1 1), the skirt (12) being connected to the connecting sleeve (1 1) by an upper annular flange (14), so as to define between them an annular space (13), the barrel portion being formed by the connecting sleeve (11), the skirt (12) and the upper annular flange (14). 5. Dispensing head according to claim 4, wherein the piston portion (P) comprises two pistons (P1, P2) respectively in sliding sealing engagement with the connecting sleeve (11) and the skirt (12). 6. Dispensing head according to claim 4 or 5, wherein the air passage (17) passes through the upper annular flange (14). 7.- dispensing head according to any one of the preceding claims, wherein the dispensing head (T; T ') comprises in in addition to a mounting housing (16; 16 ') in which is engaged a nozzle (2), the spray wall (21) being integral with the nozzle (2). 8. Dispensing head according to claim 7, wherein the differential sequencing valve (3) is engaged in the mounting housing (16) upstream of the nozzle (2). 9. Dispensing head according to claim 4, wherein the piston portion is formed by the bearing surface (41), made in the form of a deformable membrane (40) of the air chamber (C '). . 10. Dispensing head according to any one of the preceding claims, further comprising at least one filter (F1, F2) upstream of the spray wall (21).