EP3717136A1 - Method for producing a distribution wall - Google Patents

Abstract

The invention relates to a method for producing a spray wall (26) pierced with holes (O1, O2, O3), through which the pressurized fluid product passes so as to be sprayed into fine droplets, the method comprising the following steps: a- deforming a strip of initially flat, deformable material so as to create a bulged zone, b- drilling parallel holes in the bulged zone so as to create a pierced bulged zone, c- deforming the pierced bulged zone so as to create a doubly deformed, pierced zone (Z4), at which the holes (O1, O2, O3) are divergent, and d- cutting the strip around the doubly deformed, pierced zone (Z4) while advantageously leaving a flat peripheral region (Z5) around the doubly deformed, pierced zone (Z4) so as to obtain the spray wall (26).

Description

 Method of manufacturing a distribution wall

The present invention relates to a spray wall of a fluid dispensing head intended to be associated with a dispensing member such as a pump or a valve. The dispensing head may be integrated with, or mounted on, the dispenser member. The dispensing head may comprise a bearing surface so as to constitute a pusher on which the user presses to actuate the dispensing member. Alternatively, the dispensing head may be devoid of bearing surface. This type of dispensing head of fluid product is frequently used in the fields of perfumery, cosmetics or pharmacy A conventional dispensing head, for example of the pusher type, comprises:

 a support surface on which a user can press with a finger, for example the index,

 an inlet well intended to be connected to an outlet of a dispensing member, such as a pump or a valve,

 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 general, the inlet well is connected to the axial mounting housing by a single supply conduit. On the other hand, it is common to form a swirl system at the nozzle spray wall. A swirl system conventionally includes a plurality of tangential swirl channels that open into a swirl chamber centered on the spray orifice of the nozzle. The swirl system is disposed upstream of the spray orifice.

 In the document EP1878507A2, there are described several embodiments of a nozzle comprising a spray wall pierced with several spray holes of substantially identical or perfectly identical diameter, of the order of 1 to 100 miti, with a tolerance of 20% . Such a spray wall would generate a spray whose droplet size is relatively homogeneous. In one embodiment of this document, the wall is curved and the holes are then divergent. The opening angle of the spray remains low.

 In EP1698399A1, the spray wall is of constant thickness, but curved. The holes were drilled perpendicular to the plane of the wall, while the wall was still flat. The curvature of the wall makes it possible to make the holes diverge, once the curved wall. It is specified that the holes have, after bending, a constant section over their entire length. It is not explained in this document how or when the pierced flat wall is curved. In the drawings, the curvature of the bending is small, so that the opening angle of the spray is low.

 The present invention aims to define a method of manufacturing a spray wall whose opening angle is large, without being forced to resort to excessive bending, which is difficult or impossible to achieve.

 To achieve this object, the present invention provides a method of manufacturing a spray wall pierced with holes through which the pressurized fluid product passes to be sprayed into fine droplets, the method comprising the following steps:

 a- deforming a strip of initially flat deformable material so as to create a convex zone,

b- to drill parallel holes in the convex zone, so as to create a pierced convex zone, c- deforming the curved convex zone so as to create a doubly deformed pierced zone, at which the holes are diverging, and

 d- cutting the band around the doubly deformed pierced zone, advantageously leaving a flat peripheral area around the doubly deformed pierced area, so as to obtain the spray wall.

 According to a simple embodiment, step c- may comprise smoothing the convex curved zone, so as to create a double plane deformed pierced zone. In other words, we start from a flat configuration to return to a flat configuration: meanwhile, we drill the holes in a curved temporary intermediate configuration.

 According to another more successful embodiment, step c- may comprise deforming the pierced convex zone by inverting its concavity, respectively convexity, so as to create a doubly deformed pierced zone which is curved in the other direction. Both bumps may be symmetrical or asymmetrical in shape and size. The convex zone and the doubly deformed convex zone advantageously define an angle of attack of less than 30 degrees with respect to the plane peripheral zone. If you want to make a spray wall with holes inclined at 45 degrees, that is to say, a spray with an opening angle of 90 degrees, just an angle of attack of 20 to 25 degrees for each of the two curved areas. It is also possible to provide an angle of attack of 30 degrees for the convex zone and of 15 degrees for the doubly deformed, convex zone. It is therefore possible to make a spray wall with a large opening angle and a low bending.

 Advantageously, step a- comprises stamping the strip, to create the curved domed or bowl area.

Advantageously, the step d- comprises stamping the convex curved zone to create the doubly deformed double domed or cupped bored zone. Thus, one can proceed to a stamping, to a parallel drilling, then to a "counter-stamping", to bring the convex curved zone back to its original plane state or to bring it into a reverse or symmetrically convex state. This "mirror bending" has the advantage of causing the holes to diverge more towards the outside, compared to a simple

"Flattening"

 Advantageously, step b may comprise drilling holes of different diameters. For example, the holes in concentric circles may be arranged with the holes of the inner circle having a diameter smaller or larger than those of the outer circle. Step b- may also comprise drilling 10 to 500 holes having diameters of the order of 1 to 100 miti, advantageously of the order of 10 to 30 miti, and preferably of the order of 5 to 20 pm .

 Advantageously, step c- may comprise locally reducing the thickness of the pierced convex zone. This reduction in wall thickness can vary the diameter and the section of the holes.

 The invention also defines a fluid dispensing head provided with a mounting housing, a nozzle being inserted into the mounting housing, said nozzle comprising a spray wall as defined above.

 The spirit of the invention lies in the fact of drilling the holes, while the band is not flat: it can be convex or concave, in the form of hump or trough symmetry of revolution or mirror. The band can simply be bent, with or without a fold, or be pressed in the shape of a round bowl. The subsequent flat recycling or the reverse bending, once the holes drilled, causes a divergence or convergence of the holes, depending on the side considered. One can even consider using the method of the invention to create a convergent jet spray wall to create a collision dispersion phenomenon.

The invention will now be further described with reference to the accompanying drawings, giving by way of non-limiting examples, several embodiments of the invention. In the figures:

 FIG. 1 is a vertical cross-sectional view through a pump equipped with a dispensing head according to the invention,

 FIG. 2 is a greatly enlarged view of the dispensing head of FIG. 1,

 FIG. 3 is a greatly enlarged view in cross section of the spray wall of FIG. 2,

 Figures 4a to 4e are perspective views for illustrating the method of manufacturing the spray wall of Figure 3, and

 Figures 5a to 5e are sectional views corresponding to the figures

4a to 4e.

 In Figure 1, a dispensing head T is mounted on a dispensing member P, such as a pump or a valve, which has a design quite conventional in the fields of perfumery or pharmacy. This dispensing member P is actuated by the user by pressing axially with a finger, generally the index, on the head T.

 In the case of a pump, the normal pressure generated by this axial support on the fluid product inside the pump P and the head T is of the order of 5 to 6 bar, and preferably of 5.5 at 6 bars. Peaks at 7 to 8 bar are possible, but it is then in abnormal conditions of use. Conversely, at the approach of 2.5 bar, the spray is deteriorated, between 2.5 and 2.2 bar, the spray is strongly altered, and below 2 bar, there is no more spray.

 In the case of an aerosol equipped with a valve, the initial pressure generated by the propellant gas is of the order of 12 to 13 bar and then drops, as the aerosol empties, until about 6 bars. An initial pressure of 10 bars is common in the field of perfumery and cosmetics.

When the assembly comprising the head T and a pump or valve is mounted on a fluid reservoir, this constitutes a fluid dispenser, which is entirely manual, without energy input, including electrical. In comparison, in the technical field of ultrasonic vibration sprayers (especially piezoelectric), the pressure of the fluid product at the nozzle is of the order of 1 bar, that is to say the atmospheric pressure, or slightly less . Because of the pressure value used and the energy used, these ultrasonic vibration sprayers are outside the scope of the invention.

 Referring to Figures 1 to 2 to describe in detail the component parts, and their mutual arrangement, a dispensing head T made according to the invention.

 The dispensing head T comprises two essential components, namely a head body 1 and a nozzle 2. These two parts can be made by plastic injection molding. The head body 1 is preferably made in one piece: it can however be made from several parts assembled to each other. The nozzle 2 can be made monobloc mono-material, but preferably, it is made by overmolding, as will be seen below.

 The head body 1 comprises a substantially cylindrical peripheral skirt 10 which is closed at its upper end by a plate 14. The head body 1 also comprises a connecting sleeve 15 which here concentrically extends inside the body. peripheral skirt 10.

The connecting sleeve 15 extends downwardly from the plate 14. It internally defines an inlet well 11 which is open downwards and closed at its upper end by the plate 14. The connecting sleeve 15 is intended to to be mounted on the free end of an actuating rod P5 of the dispensing member P. This actuating rod P5 is movable back and forth along a longitudinal axis. The actuating rod P5 is hollow so as to define a discharge pipe in communication with a dosing chamber PO of the pump P or the valve. The inlet well 11 extends in the extension of the actuating rod P5 so that the fluid product from the dosing chamber PO can flow into the inlet well 11. The head body 1 defines also a supply duct 13 which connects the inlet well 11 to a mounting housing 12, as can be see Figure 2. The axial mounting housing 12 is of cylindrical overall configuration, thereby defining an inner wall which is substantially cylindrical. The supply duct 13 opens into the mounting housing 12 centrally. It may also be noted that the inner wall of the mounting housing 12 has attachment profiles 121 for better support of the nozzle 2, as will be seen below.

 Optionally, the head body 1 can be engaged in a covering cap 3 comprising upper bearing surface 31 for a finger and a lateral casing 32 forming a lateral opening 33 for the passage of the nozzle 2.

 The nozzle 2 has a substantially cylindrical overall configuration in the form of a small sleeve 20 which is open at both ends, but which is sealed internally by a spray wall 26 at which several holes or spray orifices 01 are formed, 02, 03. More specifically, the sleeve 20 is substantially cylindrical overall shape, preferably with axial symmetry of revolution about an axis X, as shown in Figure 2. Thus, the nozzle 2 does not need it is angularly oriented before its presentation in front of the inlet of the axial mounting housing 12. However, it is sometimes necessary to orient the nozzle 2, because its spray wall 26 is not revolution. The sleeve 20 forms an external mounting wall 21 which is advantageously provided with hooking reliefs adapted to cooperate with the attachment profiles 121 of the mounting housing 12. It may be noted that the spray wall 26 extends to level of the outer wall assembly 21, where they form a plurality of projecting lugs 27 which bite into the mounting housing 12. Once the axial assembly is completed, the nozzle 2 is in the configuration shown in Figures 1 and 2.

 The spray wall 26 is fixed to the sleeve 20 by any means, such as bi-injection, snapping, crimping, swaging, etc. Overmolding is the preferred technique.

The spray wall 26 may be a one-piece mono-material part, an assembly of several parts or a product multilayer, for example laminated. It can be made of metal, for example stainless steel. More generally, any deformable material that can be pierced with small holes or orifices can be used. The number of holes 01, 02, 03 is of the order of 30 to 500. The thickness of the spray wall 26 at the level where the holes are formed is of the order of 20 to 100 miti, advantageously 50 pm. The thickness of the spray wall 26 is preferably constant, but a variable thickness is also conceivable. The diameter of the spray wall 26 at the level where the holes are formed is of the order of 0.5 to 5 mm. The spray wall 26 is bulged outwards. The diameter of the holes is of the order of 1 to 100 μm, advantageously of the order of 10 to 30 μm, and preferably of the order of 5 to 20 μm.

 Reference will now be made to FIGS. 4a to 4e and 5a to 5e to describe the manufacturing process of the spray wall 26. Firstly, we start from a flat strip 26i of constant thickness. It may be a 50 micron thick stainless steel strip. This is shown in Figures 4a and 5a. The first step consists in deforming this flat strip 26i so as to create a convex zone Z1. This curved zone Z1 can be obtained by folding, bending or embossing the flat strip 26i. In Figures 4b and 5b, the convex zone Z1 simply results from a transverse folding of the band 26i. The angle formed by this folding can be of the order of 10 to 90 °.

The next step is to drill, for example using a laser L, parallel holes O in the convex zone Z1, so as to obtain a pierced convex zone Z2. This is also shown in Figures 4c and 5c. The holes O drilled in the center of the fold are substantially perpendicular to the curved zone Z1, while the holes made away from the center of the fold are less and less perpendicular. This is because the curved zone Z1 forms an arc or a mud, not a fold, which is however possible and would give holes with an identical inclination relative to the curved area. In a next step, the strip 26i can be flattened again so that the perforated convex zone Z2 is again deformed so as to create a doubly deformed pierced zone Z3. This is shown in Figures 4d and 5d. It may be noted that the holes 01, 02 and 03 are no longer parallel to each other, but extend in a divergent manner, due to the flattening of the pierced zone Z2. At this point, the band 26i could be cut to form a spray wall that can be integrated into a nozzle.

 However, it is also possible in the context of the present invention to carry out an additional step of bulging the convex curved zone Z2 in the other direction, as shown in Figures 4e and 5e. It is possible to go through the intermediate step of flattening of Figures 4d and 5d or proceed directly to turning the bending from the configuration of Figures 4c and 5c to that of Figures 4e and 5e. We can then notice that the divergence of the holes 01,

02 and 03 was further amplified so as to have outer holes 01 at an angle of nearly 45 ° to the X axis.

 The deformation of the pierced convex zone Z2, whether to replace it flat or to bend it in an inverted manner, can be carried out by stamping. The wall thickness can be maintained unchanged or, conversely, the wall thickness can be varied.

 The last step is to cut around the zone Z3 or Z4 leaving a flat peripheral annular range Z5. This cutting can be done by punching or laser.

Referring again to FIG. 3, it can be seen that the angle of attack α of the domed zone Z4 with respect to the plane of the plane range Z5 does not need to be large in order to obtain holes 01 having a large opening angle. This is due to the fact that the O holes were drilled parallel in the curved zone Z1, which was then turned upside down to give the inversely convex zone Z4. The angle of attack may be less than 30 °, while the opening angle of the holes 01 may be greater than or equal to 45 °. The holes 01, 02 and 03 may be arranged in concentric circles and have identical diameters, or conversely, different diameters, the diameter of the holes 01 of the outer circle may be larger or smaller than that of the holes of the inner circle.

 Thanks to the invention, one can achieve a perfectly flat spray wall with diverging holes that have been drilled parallel. More advantageously, it is possible to produce a slightly curved spray wall with highly divergent holes.

Claims

claims 1. A method of manufacturing a spray wall (26) pierced with holes (01, 02, 03) through which the fluid under pressure passes to be sprayed into fine droplets, the method comprising the following steps:  a- deforming a strip (26i) of initially flat deformable material so as to create a convex zone (Z1),  b- drilling holes (O) parallel in the convex zone (Z1), so as to create a pierced convex zone (Z2),  c- deforming the convex bored zone (Z2) so as to create a doubly deformed pierced zone (Z3; Z4), at which the holes (01, 02, 03) are diverging, and  d- cutting the strip (26i) around the doubly deformed pierced zone (Z3; Z4), advantageously leaving a planar peripheral zone (Z5) around the doubly deformed pierced zone (Z3; Z4) so as to obtain the wall spraying (26). 2. The method of claim 1, wherein step c- comprises smoothing the bowed domed area (Z2) so as to create a planar double deformed bored area (Z3). 3.- Method according to claim 1, wherein step c- comprises deforming the convex bored zone (Z2) by inverting its concavity, respectively convexity, so as to create a doubly deformed bent zone (Z4) in the other way. 4- The method of claim 3, wherein the doubly deformed bent zone (Z4) define an angle of attack (a) of less than 30 degrees from the plane peripheral range (Z5). A method as claimed in any one of the preceding claims, wherein step a comprises embossing the web (26i) to create the domed or cupped domed area (Z1). 6. The method of claim 3, wherein the step d- comprises stamping the pierced convex zone (Z2) to create the domed double-deformed convex zone (Z4) in the shape of a dome or bowl. 7. A method according to any one of the preceding claims, wherein step b- comprises drilling holes (O) of different diameters. 8. A method according to any one of the preceding claims, wherein step b- comprises drilling 10 to 500 holes having diameters of the order of 1 to 100 miti, preferably of the order of 5 to 30 miti, and preferably of the order of 5 to 20 μm. 9- A method according to any one of the preceding claims, wherein step c- comprises locally reducing the thickness of the pierced convex zone (Z2). 10- fluid dispensing head (T) provided with a mounting housing (12), a nozzle (2) being inserted into the mounting housing (12), this nozzle (2) comprising a spray wall (26); ) performed according to any one of the preceding claims.