WO2025103970A1

WO2025103970A1 - Liquid dispensing device and method for its operation

Info

Publication number: WO2025103970A1
Application number: PCT/EP2024/081938
Authority: WO
Inventors: Fanny LUDER; Guillaume Decke; Marc Schlappach; Alexis MARETTE
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2023-11-14
Filing date: 2024-11-12
Publication date: 2025-05-22
Anticipated expiration: 2026-05-14

Abstract

A liquid dispensing device (10) is for spraying a liquid, in particular for application to the human body. It comprises a container (1) for storing the liquid, an atomiser (4) for spraying the liquid, a conduit (2) for guiding the liquid to the atomiser (4), and a pump (3) arranged to drive the liquid through the conduit (2). The atomiser (4) comprises a set of at least two nozzles (41) arranged to create colliding jets of the liquid and thereby create a spray of droplets of the liquid, and each atomiser (4) comprises an associated spray shaper (45) for guiding the spray, the spray shaper (45) being a cavity through which the spray passes before exiting the atomiser (4). The pump (3) can be a positive displacement pump, in particular a peristaltic pump, acting on a section of the conduit (2) to drive the liquid through the conduit (2).

Description

LIQUID DISPENSING DEVICE AND METHOD FOR ITS

OPERATION

The invention relates to the field of spraying apparatus for discharge of liquids, in particular for application to the human body. It relates to a liquid dispensing device and method for its operation as described in the preamble of the corresponding independent claims.

WO 2011/054120 Al discloses, for example in embodiments according to Figures 4 to 6 and Figures 20 to 23, cartridges for generating a spray of a liquid, such as water or water-based mixture, from colliding jets. WO 2019/233958 Al discloses a cartridge for use in a showerhead or tap, comprising a set of at least two nozzles arranged to create colliding jets of the liquid and thereby create a spray of droplets of the liquid, and a spray shaper for guiding the spray. The spray shaper can have the form of a hollow cylinder.

• A nozzle diameter is disclosed to be from 0.8 to 1.5 or 2 millimetres, preferably approximately 1.3 millimetres.

• An angle between longitudinal axes of the nozzles is 90° +/- 20°.

• A distance between a collision point of the jets and a front surface (which is approximately equal to the length of the spray shaper) is more than 14 or 17 or 20 millimetres, and in particular less than 30 or 25 or 22 millimetres. • A maximum distance between spray shaper back end and the front surface is more than 18 or 21 or 24 millimetres, and in particular less than 33 or 28 or 25 millimetres.

• An inner diameter of spray shaper is 10 to 18 millimetres, preferably 14 millimetres.

WO 2019/233958 Al discloses the operating principles of generating a spray of a liquid by impinging jets and of forming the spray by means of the spray shaper, and is herewith incorporated in its entirety by reference.

US 2021/345748 Al relates to a hair treatment method and discloses a distribution device comprising at least two nozzles oriented such that their respective jets collide. The distribution device comprises a reservoir, a distribution head, a conduit for guiding the liquid to the distribution head, and a pump arranged to drive the liquid through the conduit.

US 9,259,540 B2 relates to the dispensing of an inhalation formulation by means of a nozzle or an inhaler. To this end, it discloses nozzles for generating a spray from impinging jets, and an inhaler with such nozzles. The nozzles are part of a deformed plate which is not suitable for guiding the spray.

WO 2019/106319 Al relates to a fluid dispensing head for use with a dispensing device such as a pump or valve. A fluid dispensing head is mountable on a container for storing a fluid to be dispensed. The device further comprises an atomiser for spraying the liquid and a conduit for guiding the liquid to the atomiser, as well as a pump arranged to drive the liquid through the conduit. The atomiser comprises multiple nozzles that create colliding jets of the liquid.

EP 3 097 981 Al relates to a spray head for a spray can, with a container and an atomiser with impinging jets, as well as a conduit for guiding the liquid to the atomiser. US 7,648,083 B2 shows a powered sprayer that has a spray head or housing that is similar in size and configuration to a standard hand operated sprayer. It comprises a dispensing head with a pump, a motor and gear assembly adapted to power the pump, a trigger adapted to actuate the motor, and a conduit from a container to a nozzle.

Effects of such sprays generated with impinging jets include a good wetting and rinsing of surfaces, due to the presence of small droplets, and an agreeable washing experience in the case of a shower or tap. These effects are combined with a reduced use of water.

There is a need to realise such effects in a wider range of operating conditions, and/or to increase the versatility of sprayers using impinging jets.

It is therefore an object of the invention to create a liquid dispensing device and method for its operation of the type mentioned initially, which provide the beneficial effects of spraying atomised water using impinging jets in a wider range of operating conditions, and/or to increase the versatility of such sprayers.

These objects are achieved by a liquid dispensing device and method for its operation according to the corresponding independent claims.

The liquid dispensing device is for spraying a liquid, in particular for application to the human body. It comprises a container for storing the liquid, an atomiser for spraying the liquid, a conduit for guiding the liquid to the atomiser, and a pump arranged to drive the liquid through the conduit. Therein, the atomiser comprises a set of at least two, in particular exactly two, nozzles arranged to create colliding jets of the liquid and thereby create a spray of droplets of the liquid, and each atomiser comprises an associated spray shaper for guiding the spray, the spray shaper being a cavity through which the spray passes before exiting the atomiser. This makes it possible to create a spray of atomised fluid in a compact self-contained unit, and with a low flow rate.

The following terms shall be used: A sprayer head comprises an atomiser. An atomiser comprises, for example, a nozzle set with two or more nozzles for creating impinging jets of water. As opposed to sprayers ordinarily used in showers, an atomiser generates a flow of a mixture of air and microscopic water droplets rather than macroscopic drops.

In embodiments, the pump is a positive displacement pump, in particular a peristaltic pump, more in particular a peristaltic pump acting on a section of the conduit to drive the liquid through the conduit.

This makes it possible exactly control the amount of liquid sprayed. It surprisingly is possible to generate a spray by impinging jets of liquid even though such pumps have relatively low flow rates.

In embodiments, at least a section of the conduit or the entire conduit is a flexible hose.

This makes it possible to make the conduit replaceable. The conduit can be part of the peristaltic pump, with rollers of the pump acting on the conduit and transporting the liquid through the conduit.

In embodiments, the container comprises a movable container section designed to move to reduce a volume of the container as liquid is pumped out of the container, in particular wherein the container's inner shape is that of a cylinder, and the movable container section is a piston that is movable along the cylinder. This allows to adapt the volume of the container as the liquid is pumped out. For filling the container, the movable container section can be retracted while filling the container through the conduit or another opening in the container. In embodiments, the container is a flexible sac.

In embodiments, the liquid dispensing device is a hand-held unit, with its components arranged in or attached to a compact housing, in particular with the housing enclosing at least the conduit, the pump, a motor for driving the pump, a driver circuit for driving the motor, and a button connected to the driver circuit for controlling operation of the pump.

That is, the liquid dispensing device is a unit that can be transported and handled as a single hand-held unit. In embodiments, the weight of the liquid dispensing device without the container is less than one kilogram. In embodiments, the device's height is less than twenty-five centimetres, its length is less than twenty-five centimetres and its width is less than ten centimetres.

In embodiments, the liquid dispensing device comprises a user-replaceable sub-unit, designed to be removed for replacement by uncoupling the sub-unit from the liquid dispensing device, wherein one of the following is the case:

• the sub-unit comprises only the container;

• the sub-unit comprises only the container and the conduit;

• the sub-unit comprises the container and the conduit and the atomiser.

The term user-replaceable means that the sub-unit is designed to be removed and replaced with another sub-unit of the same type by a user of the liquid dispensing device, preferably without the use of tools. In particular, the liquid dispensing device can be designed for replacement of the container by uncoupling the container from the liquid dispensing device. In embodiments, the elements of the sub-unit are attached to one another by permanent connections. That is, they cannot be detached from one another without irreversibly breaking the connection.

This makes it possible to replace the container and optionally further elements, eliminating the need to clean them after use or when switching to a different liquid.

In embodiments, in the atomiser a distance between a point at which the jets collide and an outlet opening of the spray shaper, this distance to be called length of the spray shaper, lies between three and twenty millimetres, in particular between four and twelve millimetres, in particular between six and ten millimetres, in particular between seven and nine millimetres.

This makes it possible to focus the spray of atomised liquid precisely. The spray shaper narrows the spray to have an approximately cylindrical shape, or that of a truncated cone with a small cone angle.

The aperture of a right circular cone is the maximum angle between two generatrix lines. The cone angle 0 is the angle between the generatrix and the cone’s axis, so the aperture is 20.

In embodiments, in the atomiser an inner diameter of the spray shaper lies between one and a half and fourteen millimetres, in particular between two and ten millimetres, in particular between five and seven millimetres.

This contributes to focussing the spray of atomised liquid precisely.

In embodiments, in the atomiser the diameter of the nozzles lies between 0.3 and 1.2 millimetres, in particular between 0.3 and 0.4 millimetres. This makes it possible operate the liquid dispensing device with a relatively low flow rate. Then, even at low flow rates, the jets of liquid created by the nozzle have sufficient speed and kinetic energy for atomising the liquid.

In embodiments, the number of nozzles in the atomiser is two. The nozzles lie in a common plane, and typically are aligned for the jets to meet one another with maximal overlap. This maximises the efficiency of the atomisation.

In embodiments, the number of nozzles in the atomiser is four. The nozzles can be arranged to meet at a single collision point. Pairs of opposing nozzles can have the angle between each nozzle and the spray axis being the same. In embodiments, the number of nozzles in the atomiser is five, with four nozzles at an angle to the spray axis and the fifth nozzle coinciding with the spray axis.

In embodiments, in the atomiser a half-angle between colliding jets lies between 10 and 75 degrees, in particular between 15 and 45 degrees, in particular between 20 and 30 degrees.

This makes it possible to impart a forward impulse to the droplets of the atomised spray.

In embodiments, the atomiser has the following combination of parameters:

• the diameter D2 of the nozzles lies between 0.3 and 1.2 millimetres, in particular between 0.3 and 0.4 millimetres;

• the half-angle a between colliding jets lies between 10 and 75 degrees, in particular between 15 and 45 degrees, in particular between 20 and 30 degrees;

• the inner diameter Ds of the spray shaper lies between one and a half and fourteen millimetres, in particular between two and ten millimetres, in particular between five and seven millimetres; the length of the spray shaper Ls, lies between three and twenty millimetres, in particular between four and twelve millimetres, in particular between six and ten millimetres, in particular between seven and nine millimetres.

These dimensions make it possible to create a spray by impinging jets at a comparatively low flow rate and at low pressures, when compared to known applicators in the sanitary or body care domain.

In embodiments, in the atomiser the spray shaper exits a front surface of the atomiser, with a recess shaped in the front surface intersecting the spray shaper, in particular wherein the recess is elongated in a direction, to be called longitudinal direction of the recess, in particular wherein the atomiser comprises exactly two nozzles arranged in a plane and with the longitudinal direction of the recess being orthogonal to that plane.

This makes it possible to shape the spray of atomised liquid to be elongated in the same direction as the recess. Conversely, it reduces the dimension of the spray in the direction of the plane in which the nozzles lie. This allows to control the application of the spray to a surface, such as part of the human body.

An atomiser with such a shape can be implemented independently from the atomiser's combination with the liquid dispensing device described herein. That is, for an atomiser according to a further aspect of the invention it is the case that

• the atomiser comprises a set of at least two, in particular exactly two, nozzles arranged to create colliding jets of the liquid and thereby create a spray of droplets of the liquid, and

• each atomiser comprising an associated spray shaper for guiding the spray, the spray shaper being a cavity through which the spray passes before exiting the atomiser; • the spray shaper exits a front surface of the atomiser, with a recess shaped in the front surface intersecting the spray shaper.

Also, any other properties of an atomiser described herein can be implemented in combination with an atomiser with such a shape.

A recess can also be called a groove, a slit, a slot, a cutout, or a channel or an indentation. In order to create an at least approximately planar sheet of water, the recess can be shaped long and narrow. A length of the recess can be at least four or at least five or at least six times its width.

In embodiments, a maximum width of the recess, in a direction normal to its longitudinal direction and in regions where the recess does not intersect the spray shaper is smaller than a diameter Ds of the spray shaper inner wall, in particular less than 90% or less than 80% or less than 70% of the diameter Ds.

This makes it possible to create a spray in the shape of a narrow planar shape, or in the shape of a truncated pyramid with a small opening angle.

In embodiments, the recess, in a direction normal to its longitudinal direction, is the same or larger than a diameter Ds of the spray shaper inner wall, in particular less than four times or less than three times or less than twice or less 150% or less than 110% of the diameter Ds.

In any case, the recess can be aligned symmetrically or asymmetrically with regard to the longitudinal axis of the spray shaper. This allows to control the direction of the spray after it has left the atomiser.

In embodiments, one (first) side wall of the recess is near to or locally is flush with a section of the spray shaper inner wall, whereas an opposite side wall of the recess is so far from the spray shaper so as to have no noticeable effect on the spray. The recess can be cut out so that no opposite side wall is present. This causes the spray on the side of the first wall to be constrained by the wall, and on the opposite side to be essentially not constrained, except by the remainder of the spray shaper.

In embodiments, the recess is arranged in an at least approximately conical front surface of the atomiser 4, in particular with an aperture angle 0 of the front surface being between 60° and 85°.

The effect of the conical front surface is to guide an air flow to join the spray with little turbulence. The effect of the angle between the front surface and the inner wall being an acute angle, such as an angle below 85°, is to reduce or eliminate a deflection of the flow of water around the edge between the inner wall and the front surface.

In embodiments, the recess where it intersects the spray shaper has a depth between 20% and 100% of the length Ls of the spray shaper, in particular a depth between 30% and 80%, more in particular a depth between 40% and 60% of the length Ls of the spray shaper.

This allows for the recess to sufficiently affect the shape of the spray as it exits the spray shaper.

In embodiments, the liquid dispensing device is configured to receive a further fluid from a further container, or from an external supply, to mix the fluid with the further fluid to form a fluid mixture and to spray the fluid mixture through the atomiser.

The further container can be part of the liquid dispensing device and can be arranged in the same housing or attached to the same housing. In-line mixing of the second fluid with the first fluid in the hand-held applicator can be advantageous in many cases, especially when a certain interaction or effect can be activated by blending of the two fluids or when in certain cases, it might be beneficial to dilute the first fluid with a second fluid, such as water.

The method for operating the liquid dispensing device comprises the steps of providing the liquid to the atomiser 4 with a pressure between 0.1 bar and 1.5 bar or 2 bar or 3 bar, in particular of at least approximately 0.2 bar, and with a resulting flow rate of between 0.03 and 0.4 litres per minute in the atomiser, and more in particular, with a flow rate in the atomiser being around 0.04 litres per minute at a pressure of 0.2 bar. These numbers are applicable for a liquid with a viscosity close to that of water. For higher viscosities, the pressure can be increased.

It has been found that with such low flow rates and pressures it is possible to reliably create an atomised spray. This reduces the power needed and the weight of a handheld device.

Further embodiments are evident from the dependent patent claims. Features of the device claims may be combined with features of the method claims and vice versa.

The subject matter of the invention will be explained in more detail in the following text with reference to exemplary embodiments which are illustrated in the attached drawings, which schematically show:

Figure 1 a liquid dispensing device;

Figure 2 the liquid dispensing device in a sectional view;

Figure 3 a schematic structure of the liquid dispensing device;

Figure 4 a sprayer head with an atomiser;

Figure 5 the sprayer head seen from its back side;

Figure 6 a cut view of the sprayer head, in the plane indicated in Figure 5;

Figure 7 a detailed view of the Figure 6;

Figure 8a-8c views of a sprayer head with a recess, according to a first embodiment; Figure 9a-9c the same, for a second embodiment;

Figure 10a- 10c the same, for a third embodiment;

Figure 11 a sprayer head with an asymmetric recess.

In principle, identical or functionally identical parts are provided with the same reference symbols in the figures.

Figure 1 shows a liquid dispensing device 10 in a perspective view. The liquid dispensing device 10 comprises a housing 6 with at handle section 61 for holding it, a container 1 with a movable container section 11 for storing a liquid to be dispensed, a sprayer head 5 for spraying the liquid, and a button 62 for manually activating the spraying. Figure 2 shows further components in a sectional view: a pump 3 is arranged to deliver the liquid from the container 1 through a conduit (not shown) to the sprayer head 5. The pump 3 is driven by a motor 64 controlled by a driver circuit 63. The liquid dispensing device 10 can comprise a battery for powering the motor 64, or it can be powered through an electric supply cable. As liquid is drawn from the container 1, the movable container section 11 , in this embodiment a piston or plunger, moves to reduce the volume of the container 1.

Figure 3 shows a schematic structure of the liquid dispensing device. The conduit 2 is shown connecting the container 1 to the atomiser 4 and being part of a pump 3. The pump 3 is a peristaltic pump with rollers 31 driving the liquid through the conduit 2. According to different embodiments, one or more of the elements are combined and are designed to be removed and replaced as a sub-unit.

• In a first embodiment, the container 1, with or without a movable container section 11 , forms the replaceable sub-unit.

• In a second embodiment, the container 1 , with or without a movable container section 11 , combined with the conduit 2 forms the replaceable sub-unit. • In a third embodiment, the container 1 , with or without a movable container section 11, combined with the conduit 2 and the atomiser 4 forms the replaceable sub-unit.

The ability to remove and replace such sets of elements eliminates the need to clean the elements when changing the composition of the liquid dispensed.

In general, except for the third above embodiment, it can be the case that the sprayer head 5 with the atomiser 4 is replaceable without removing any of the other elements. This allows to quickly adapt the liquid dispensing device 10 to work with different spraying characteristics, determined by the type of atomiser 4. The sprayer head 5 can be attached to the housing 6 by a screw or bayonet or other connection.

Figures 4 - 7 show a sprayer head 5 comprising an atomiser 4 and further elements, such as a thread, for holding and attaching the atomiser 4 to the housing 6. In the atomiser 4, the colliding jets create a spray, which is guided and shaped by a cavity, to be called spray shaper 45. The spray shaper 45 can be a cylindrical volume. The colliding jets from the nozzles 41 create an initial spray that flows through and is guided by an inner wall 47 of the spray shaper 45. The spray shaper 45 surrounds the initial spray, and the inner wall of the spray shaper 45 is an inside wall of a cavity. The cavity extends along a longitudinal axis and can be symmetrical with regard to this longitudinal axis. The longitudinal axis typically coincides with the bisecting line between the nozzles 41. At an outer end of the spray shaper 45, it terminates in a spray shaper rim 48. See in a longitudinal cross section, the spray shaper rim 48 forms an acute angle between the spray shaper inner wall 47 and the front surface 49. This prevents the spray from adhering to the spray shaper inner wall 47 at the spray shaper rim 48.

When a pair of nozzles is present, creating impinging the jets of water, the nozzles are arranged in mirror-symmetric fashion regarding one another, defining a plane of symmetry and a spray axis, the spray axis being defined by the projection of the direction of the impinging jets onto the plane of symmetry;

In other words, a bisecting line between the nozzles 41 defines a main longitudinal axis of the spray, or simply the spraying direction or spray axis. Initially, right after the collision point, the spray has a disc-like shape. The spray shaper 45 by itself, having a constricted and circular cross section, achieves a more homogeneous distribution of the spray, such as an almost homogeneous circular distribution, seen in a plane normal to the spray axis.

Figure 7 schematically shows main parameters describing the shape of the nozzles 41. The nozzles 41 are shaped as part of the atomiser 4 in the body of the sprayer head 5. The nozzles 41 are arranged for a liquid, typically water or a water-based mixture, to flow - in this sequence - from a nozzle inlet 42 through a converging section 43, throat 44, and an outlet. After exiting the outlet, the liquid can flow, as a jet of liquid, into a recess forming a spray shaper back end 46 of the spray shaper 45. There it can collide with a second jet of liquid and form the spray. Longitudinal axes of the nozzles 41 are shown in dash-dotted lines. A half angle between the longitudinal axes of the nozzles 41 and the spray shaper 45 is denoted a (alpha).

The diameter in the throat 3 - generally called the diameter D2 or the hydraulic diameter of the nozzle - corresponds to the diameter of the water jet after exiting the nozzle 41 under ideal conditions, that is, with laminar flow and no diverging of the liquid after exiting the nozzle, e.g. caused by adhesion. Typical values of D2 are between 0.3 and 1.2 millimetres, in particular between 0.3 and 0.4 millimetres.

An inner diameter Ds of the spray shaper 45 lies between one and a half and fourteen millimetres. The length of the spray shaper Ls, lies between three and twenty millimetres. A half-angle a between colliding jets lies between 10 and 75 degrees. The sprayer head 5 is typically manufactured from a plastic material.

The remaining embodiments show sprayer heads 5 with different types of recess intersecting the spray shaper 45 and thereby affecting the shape of the spray as it is shaped by the spray shaper 45 in combination with the recess 50.

Figures 8a-8c show views of a sprayer head 5 with a recess 50, according to a first embodiment. The recess 50 has the shape of a rectangular slit, with a width that is the same as the diameter of the spray shaper 45. The recess, and in particular a bottom surface of the recess, runs at a right angle to the longitudinal axis of the spray shaper 45, with a depth Dr of the recess 50 being approximately half the length Ls of the spray shaper 45. If the bottom surface lies in a plane, then the length of the recess 50 is determined by the shape of the front surface 49.

Figures 9a-9c show views of a sprayer head 5 with a recess 50, according to a second embodiment. The recess 50 also has the shape of a rectangular slit, but with a width that is less than the diameter of the spray shaper 45. For the remaining dimensions, the same is the case as for the embodiment of Figures 8a-8c.

Figure lOa-lOc show views of a sprayer head 5 with a recess 50, according to a third embodiment. The recess 50 has the shape of a lozenge. More generally, it extends in a direction normal to the longitudinal axis of the spray shaper 45, being widest in the region of the spray shaper 45 and getting narrower with the distance from the spray shaper 45. In the embodiment shown, in a cross section view normal to the longitudinal axis of the recess 50, it has a V-shape. For the remaining dimensions, the same is the case as for the embodiment of Figures 8a-8c

Figure 11 shows a sectional detail of a sprayer head with an asymmetric recess 50. On one side, a (first) side wall of the recess 50 has the shape as in one of the preceding embodiments. On the other side, the opposite side wall is moved far away from the spray shaper 45 and has no significant effect on the shape of the spray. In the embodiment shown, the opposite side wall defined by the imaginary rectangle that defines the cross section of the recess 50 does not intersect the front surface 49 at all. The recess 50 is evident as the (first) side wall 51 and a bottom surface 53.

In embodiments, the liquid dispensing device 10 can be used according to a method comprising the steps of:

1. Providing the liquid dispensing device 10 without the container 1 being attached. The liquid dispensing device 10 is designed to be connected to the container 1.

2. Attaching the container 1 to the liquid dispensing device 10. A flexible conduit section of the conduit 2, which can be attached to the container 1, comes into contact with pumping elements, in particular rollers 31 of the liquid dispensing device 10, forming a positive displacement pump for pumping a first fluid contained in an inner volume of the container 1 through the conduit 2 and the sprayer head 5.

3. Optionally, an external supply unit can be attached to the liquid dispensing device 10.

In this case, the external supply unit can supply a second fluid, for example in hair coloring applications a primer or a dilution fluid such as water, to the liquid dispensing device 10. The second fluid is in-line mixed with the first fluid in the liquid dispensing device 10.

4. Starting the operation of the liquid dispensing device 10 and thereby applying the first fluid or a mix of the first fluid and the second fluid to a surface, for example on a human skin or scalp.

The hand held-held applicator is started by (A) turning on the motor 64 driving the pumping elements, which to pump the first fluid from the inner volume, and optionally, (B) opening a valve which releases a flow of the second fluid to be in-line mixed with the first fluid in the liquid dispensing device 10.

5. Stopping the operation of the liquid dispensing device 10 when the application of the fluid to the surface is completed. The operation of the hand-held applicator is stopped by (A) turning off the motor driving the pumping elements, which stops the pumping of the first fluid from the inner volume and optionally, (B) closing the valve which stops the flow of the second fluid to the liquid dispensing device 10.

6. Removing the container 1.

After the operation has been stopped, the container 1 can be removed from the liquid dispensing device 10.

7. Optionally, rinsing the liquid dispensing device 10 with a rinsing fluid, which optionally can be supplied by the external supply unit.

Depending on the design of the liquid dispensing device 10 and its container 1, it can be advantageous to rinse the liquid dispensing device 10 before re-using it. The liquid dispensing device 10 can be rinsed with a rinsing fluid, for example water. The rinsing fluid can be provided by the external supply unit or can be water directly supplied by a tap.

While the invention has been described in present embodiments, it is distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practised within the scope of the claims.

Claims

P A T E N T C L A I M S

1. A liquid dispensing device (10) for spraying a liquid, in particular for application to the human body, comprising a container (1) for storing the liquid, an atomiser (4) for spraying the liquid, a conduit (2) for guiding the liquid to the atomiser (4), and a pump (3) arranged to drive the liquid through the conduit (2), characterized in that the atomiser (4) comprises a set of at least two, in particular exactly two, nozzles (41) arranged to create colliding jets of the liquid and thereby create a spray of droplets of the liquid, and each atomiser (4) comprising an associated spray shaper (45) for guiding the spray, the spray shaper (45) being a cavity through which the spray passes before exiting the atomiser (4).

2. The liquid dispensing device (10) of one of the preceding claims, wherein the pump (3) is a positive displacement pump, in particular a peristaltic pump, more in particular a peristaltic pump acting on a section of the conduit (2) to drive the liquid through the conduit (2).

3. The liquid dispensing device (10) of one of the preceding claims, wherein at least a section of the conduit (2) or the entire conduit (2) is a flexible hose.

4. The liquid dispensing device (10) of one of the preceding claims, wherein the container (1) comprises a movable container section (11) designed to move to reduce a volume of the container (1) as liquid is pumped out of the container (1), in particular wherein the container's (1) inner shape is that of a cylinder, and the movable container section (11) is a piston that is movable along the cylinder.

5. The liquid dispensing device (10) of one of the preceding claims, being a handheld unit, with its components arranged in or attached to a compact housing (6), in particular with the housing (6) enclosing at least the conduit (2), the pump (3), a motor (64) for driving the pump (3), a driver circuit (63) for driving the motor (64), and a button (62) connected to the driver circuit (63) for controlling operation of the pump (3).

6. The liquid dispensing device (10) of one of the preceding claims, comprising a user-replaceable sub-unit, designed to be removed for replacement by uncoupling the sub-unit from the liquid dispensing device (10), wherein one of the following is the case:

• the sub-unit comprises only the container (1);

• the sub-unit comprises only the container (1) and the conduit (2);

• the sub-unit comprises the container (1) and the conduit (2) and the atomiser (4).

7. The liquid dispensing device (10) of one of the preceding claims, wherein in the atomiser (4) a distance between a point at which the jets collide and an outlet opening of the spray shaper (45), this distance to be called length of the spray shaper (Ls), lies between three and twenty millimetres, in particular between four and twelve millimetres, in particular between six and ten millimetres, in particular between seven and nine millimetres.

8. The liquid dispensing device (10) of one of the preceding claims, wherein in the atomiser (4) an inner diameter (Ds) of the spray shaper (45) lies between one and a half and fourteen millimetres, in particular between two and ten millimetres, in particular between five and seven millimetres.

9. The liquid dispensing device (10) of one of the preceding claims, wherein in the atomiser (4) the diameter (D2) of the nozzles lies between 0.3 and 1.2 millimetres, in particular between 0.3 and 0.4 millimetres.

10. The liquid dispensing device (10) of one of the preceding claims, wherein in the atomiser (4) a half-angle (a) between colliding jets lies between 10 and 75 degrees, in particular between 15 and 45 degrees, in particular between 20 and 30 degrees.

11. The liquid dispensing device (10) of one of the preceding claims, wherein the atomiser (4) has the following combination of parameters:

• the diameter (D2) of the nozzles lies between 0.3 and 1.2 millimetres, in particular between 0.3 and 0.4 millimetres;

• the half-angle (a) between colliding jets lies between 10 and 75 degrees, in particular between 15 and 45 degrees, in particular between 20 and 30 degrees;

• the inner diameter (Ds) of the spray shaper (45) lies between one and a half and fourteen millimetres, in particular between two and ten millimetres, in particular between five and seven millimetres;

• the length of the spray shaper (Ls), lies between three and twenty millimetres, in particular between four and twelve millimetres, in particular between six and ten millimetres, in particular between seven and nine millimetres.

12. The liquid dispensing device (10) of one of the preceding claims, wherein in the atomiser (4) the spray shaper (45) exits a front surface (49) of the atomiser (4), with a recess (50) shaped in the front surface (49) intersecting the spray shaper (45), in particular wherein the recess (50) is elongated in a direction, to be called longitudinal direction of the recess, in particular wherein the atomiser (4) comprises exactly two nozzles (41) arranged in a plane and with the longitudinal direction of the recess (50) being orthogonal to that plane.

13. The liquid dispensing device (10) of claim 12, wherein a maximum width of the recess (50), in a direction normal to its longitudinal direction and in regions where the recess (50) does not intersect the spray shaper (45) is smaller than a diameter (Ds) of the spray shaper inner wall (47), in particular less than 90% or less than 80% or less than 70% of the diameter (Ds).

14. The liquid dispensing device (10) of claim 12, wherein a maximum width of the recess (50), in a direction normal to its longitudinal direction, is the same or larger than a diameter (Ds) of the spray shaper inner wall (47), in particular less than four times or less than three times or less than twice or less 150% or less than 110% of the diameter (Ds).

15. The liquid dispensing device (10) of one of claims 12 to 14, wherein the recess (50) is arranged in an at least approximately conical front surface (49) of the atomiser 4, in particular with an aperture angle (0) of the front surface (49) being between 60° and 85°.

16. The liquid dispensing device (10) of one of claims 12 to 15, wherein the recess (50) where it intersects the spray shaper (45) has a depth between 20% and 100% of the length (Ls) of the spray shaper (45), in particular a depth between 30% and 80%, more in particular a depth between 40% and 60% of the length (Ls) of the spray shaper (45).

17. The liquid dispensing device (10) according to any one of the previous claims, configured to receive a further fluid from a further container or from an external supply, to mix the fluid with the further fluid to form a fluid mixture and to spray the fluid mixture through the atomiser (4).

18. A method for operating the liquid dispensing device (10) of one of claims 1 to

17, for dispensing a liquid, comprising the steps of providing the liquid to the atomiser 4 with a pressure between 0.1 bar and 1.5 bar or 2 bar or 3 bar, in particular of at least approximately 0.2 bar, and with a resulting flow rate of between 0.03 and 0.4 litres per minute in the atomiser (4), and more in particular, with a flow rate in the atomiser (4) being around 0.04 litres per minute at a pressure of 0.2 bar.

19. An atomiser (4) for spraying a liquid, in particular for use in the liquid dispensing device (10) of one of claims 1 to 17, in particular for application to the human body, the atomiser (4) comprising a set of at least two, in particular exactly two, nozzles (41) arranged to create colliding jets of the liquid and thereby create a spray of droplets of the liquid, and each atomiser (4) comprising an associated spray shaper (45) for guiding the spray, the spray shaper (45) being a cavity through which the spray passes before exiting the atomiser (4), wherein in the atomiser (4) the spray shaper (45) exits a front surface (49) of the atomiser (4), with a recess (50) shaped in the front surface (49) intersecting the spray shaper (45), in particular wherein the recess (50) is elongated in a direction, to be called longitudinal direction of the recess, in particular wherein the atomiser (4) comprises exactly two nozzles (41) arranged in a plane and with the longitudinal direction of the recess (50) being orthogonal to that plane.