Nozzle unit, liquid dispenser comprising such a nozzle unit, and methods for producing such nozzle units

Abstract

Two sub-methods are used together to produce a nozzle unit for a liquid dispenser. The methods include adding a nozzle plate into a nozzle channel of a nozzle unit using an assembly tool which elastically expands the nozzle channel. The assembly tool is inserted in the nozzle channel and expands same, thus moving the nozzle plate into its final position where it remains after the assembly tool is removed. The methods also include attaching a filter to a nozzle unit carrier. In a preparation step, a flat filter material is positioned on the end face of the carrier. Only after the filter material is positioned and a connection of the filter material to the end face is established, a separation process is carried out by which the filter material is cut to surround the end face. The filter material positioned on the end face and cut in situ remains.

Claims

1. A method for producing a nozzle unit for a liquid dispenser, the nozzle unit including a plastic carrier traversed by a nozzle channel from an inlet side to an outlet side, a nozzle channel wall defining the nozzle channel, and a nozzle plate arrangement having a multiplicity of nozzle openings, the method comprising the steps of: providing an assembly tool having an outer contour, the outer contour being oversized in relation to the nozzle channel, and an end face larger than an outer contour of the nozzle plate arrangement; bringing the plastic carrier into a defined assembly position; inserting the nozzle plate arrangement and then the assembly tool in a joining direction into the nozzle channel from the inlet side; progressively inserting the assembly tool into the nozzle channel in the joining direction and applying force to the nozzle channel wall with the assembly tool to partially elastically expand the nozzle channel wall outwardly from an initial unexpanded starting position to bring the nozzle plate arrangement to an end position within the nozzle channel at an elastically expanded area of the nozzle channel wall; pulling the assembly tool out of the nozzle channel counter to the joining direction and permitting the elastically expanded nozzle channel wall to move back inwardly towards the initial unexpanded starting position, wherein the nozzle plate arrangement remains in the end position at the elastically expanded area of the nozzle channel wall; and completely removing the assembly tool from the nozzle channel, thereafter the nozzle plate arrangement being held at the end position by the elastically expanded area of the nozzle channel wall as a result of the movement of the nozzle channel wall back inwardly towards the initial unexpanded starting position.

2. The method as claimed in claim 1, wherein the nozzle plate arrangement is configured as a one-piece nozzle plate, and the method further comprises punching out, by a punching process, the one-piece nozzle plate from a carrier plate with a plurality of nozzle plate regions, and after the one-piece nozzle plate has been punched out, directly inserting the one-piece nozzle plate into the nozzle channel in the joining direction from the inlet side.

3. The method as claimed in claim 1, wherein the nozzle channel has at least one conical sub-portion, the at least one conical sub-portion, at an end thereof pointing in a direction of the inlet side, has a cross section larger than the outer contour of the assembly tool, and, at an end pointing in a direction of the outlet side, the at least one conical sub-portion has a cross section smaller than the outer contour of the assembly tool, and during the step of progressively inserting the assembly tool into the nozzle channel, the assembly tool comes into contact with the nozzle channel wall of the nozzle channel at the at least one conical sub-portion.

4. The method as claimed in claim 1, wherein during the step of progressively inserting the assembly tool into the nozzle channel in the joining direction, an auxiliary tool is inserted, in alignment with the assembly tool, into the nozzle channel from the outlet side.

5. The method as claimed in claim 4, wherein the end face of the assembly tool has a convexly curved shape and/or an end face of the auxiliary tool has a concavely curved end face, and during the step of progressively inserting the assembly tool into the nozzle channel, the concave shape and/or the convex shape presses the nozzle plate arrangement elastically and/or plastically into a curved shape.

6. The method as claimed in claim 1, further including orienting the plastic carrier, in the defined assembly position, so that the inlet side points upward and the outlet side points downward, and after pulling the assembly tool out of the nozzle channel, heating the nozzle plate arrangement, at least in parts, at least up to 100 C.

7. The method as claimed in claim 1, wherein after the step of inserting the nozzle plate arrangement and then the assembly tool in the joining direction into the nozzle channel from the inlet side, the method further includes positioning a planar filter material on an end face of the plastic carrier and thereafter cutting the filter material circumferentially around the end face such that a flat filter remains positioned on the end face of the plastic carrier.

8. A nozzle unit for a liquid dispenser, comprising: a plastic carrier having an inlet side, an outlet side, a nozzle channel traversing the plastic carrier from the inlet side to the outlet side, and at least one annular region defining part of the nozzle channel, at least the at least one annular region of the plastic carrier comprising an elastic plastic material; and a nozzle plate arrangement inserted into the nozzle channel between the inlet side and the outlet side and having a multiplicity of nozzle openings, the at least one annular region of the plastic carrier comprising a compressed elastic portion of the elastic plastic material in an elastically compressed state, the compressed elastic portion in the elastically compressed state surrounding the nozzle plate arrangement.

9. The nozzle unit as claimed in claim 8, wherein the nozzle plate arrangement has a shape curved in a direction of the outlet side.

10. The nozzle unit as claimed in claim 8, wherein the nozzle plate arrangement has a round outer contour.

11. The nozzle unit as claimed in claim 8, wherein the nozzle channel has a tapering shape.

12. The nozzle unit as claimed in claim 8, wherein the nozzle plate arrangement comprises a one-piece nozzle plate.

13. The nozzle unit as claimed in claim 8, wherein the nozzle plate arrangement comprises a one-piece nozzle plate having an outer contour and a carrier frame fixed to the one-piece nozzle plate and having a central aperture, the carrier frame being disposed on a side of said one-piece nozzle plate facing said inlet side of said plastic carrier, said carrier frame having an outer contour smaller than the outer contour of the one-piece nozzle plate, the outer contour of the one-piece nozzle plate being firmly fixed in the compressed elastic portion in the elastically compressed state of the at least one annular region of the plastic carrier.

14. The nozzle unit as claimed in claim 13, wherein the outer contour of the one-piece nozzle plate comprises a tapering edge region in contact with the compressed elastic portion in the elastically compressed state of the at least one annular region of the plastic carrier.

15. The nozzle unit as claimed in claim 8, wherein the nozzle channel has, at an end pointing in a direction of the inlet side, a cross section larger than an outer contour of the nozzle plate arrangement, the nozzle plate arrangement comprises a nozzle plate having at least 10 nozzle openings, the nozzle openings have an average diameter of between 1 m and 100 m, the plastic carrier, in the at least one annular region, comprises a nozzle channel wall surrounding the nozzle channel and having a wall thickness between 10% and 80% of a width of the nozzle channel, and an outer diameter of the nozzle channel wall is between 3 mm and 15 mm and the wall thickness of the nozzle channel wall is between 10% and 30% of the outer diameter.

16. The nozzle unit as claimed in claim 8, wherein the plastic carrier comprises PET, and the nozzle plate arrangement comprises a metallic material comprising nickel or silicon.

17. The nozzle unit as claimed in claim 8, wherein the plastic carrier has an end face at the inlet side annularly surrounding the nozzle channel, and the nozzle unit further comprises a flat filter disposed on the end face.

18. The nozzle unit as claimed in claim 8, wherein the compressed elastic portion is configured to exert a compressive inward force on the nozzle plate arrangement.

19. A nozzle unit for a liquid dispenser, comprising: a plastic carrier traversed by a nozzle channel from an inlet side to an outlet side, the plastic carrier having, at the inlet side, an end face annularly surrounding the nozzle channel, the end face defining therein a depression having a surface area being at least a factor of 2 as large as a minimum cross-sectional area of the nozzle channel; and a flat filter for filtering discharged liquid, the flat filter lying on the end face of the plastic carrier.

20. The nozzle unit as claimed in claim 19, wherein the end face and the flat filter together define a surface, the surface closing the plastic carrier at the inlet side and no other portion of the plastic carrier protrudes beyond the surface.

21. The nozzle unit as claimed in claim 19, further comprising a nozzle plate arrangement inserted into the nozzle channel between the inlet side and the outlet side and having a multiplicity of nozzle openings, and the flat filter is configured to filter the liquid before delivery of the liquid to the nozzle plate arrangement.

22. The nozzle unit as claimed in claim 19, further comprising a clamping element connected to the plastic carrier, the flat filter being clamped between the end face of the plastic carrier and the clamping element.

23. The nozzle unit as claimed in claim 19, wherein the flat filter is configured as a self-supporting membrane filter, or the flat filter is configured as a layer composite including a carrier layer of a coarse-pored nonwoven, and a membrane filter, the coarse-pored nonwoven comprising PE, and the membrane filter comprising PET, or the flat filter is configured as a depth filter, or the flat filter has a separation limit of between 0.5 m and 100 m.

24. A liquid dispenser for discharging a liquid, comprising: a liquid reservoir; a housing; and a nozzle unit inserted into the housing of the liquid dispenser, the nozzle unit comprising: a plastic carrier having an inlet side, an outlet side, a nozzle channel traversing the plastic carrier from the inlet side to the outlet side, and at least one annular region, at least the at least one annular region of the plastic carrier comprising an elastic plastic material; and a nozzle plate arrangement inserted into the nozzle channel between the inlet side and the outlet side and having a multiplicity of nozzle openings, the at least one annular region of the plastic carrier comprising a compressed elastic portion of the elastic plastic material in an elastically compressed state, the compressed elastic portion in the elastically compressed state surrounding the nozzle plate arrangement.

25. The liquid dispenser as claimed in claim 24, comprising at least one of the following: the liquid reservoir has a maximum volume of between 10 ml and 1000 ml; and/or the liquid dispenser comprises a manually actuatable pump device, the pump device conveying the liquid from the liquid reservoir to the nozzle unit; and/or the liquid reservoir comprises a pressure reservoir, the pressure reservoir storing the liquid under pressure, and the liquid comprises cosmetic or pharmaceutical liquid.

26. The liquid dispenser as claimed in claim 24, wherein the compressed elastic portion is configured to exert a compressive inward force on the nozzle plate arrangement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages and aspects of the invention will become clear from the claims and from the following description of preferred illustrative embodiments of the invention, which are explained below with reference to the figures.

(2) FIG. 1 shows a liquid dispenser, which exemplifies a typical use of a nozzle unit according to the invention.

(3) FIGS. 2 to 4 show, in an exploded view, a parts view and a sectional view, a first illustrative embodiment of a nozzle unit according to the invention and parts thereof.

(4) FIGS. 4A to 4D show details and detail variants of FIG. 4.

(5) FIGS. 5A to 5G show a first sub-method for producing the nozzle unit of FIGS. 2 to 4, in the context of which a nozzle plate arrangement is inserted into the nozzle channel of the nozzle unit.

(6) FIGS. 6A to 6C illustrate a second sub-method for producing the nozzle unit of FIGS. 2 to 4, in the context of which a filter is mounted on the nozzle unit.

(7) FIGS. 7 and 8 show a second illustrative embodiment of a nozzle unit according to the invention in a sectional view and an exploded view.

(8) FIGS. 9 to 11 show further illustrative embodiments of a nozzle unit according to the invention, which have an additional clamping element for fastening the filter.

(9) FIGS. 12 and 13 show an illustrative embodiment of the nozzle unit with a curved nozzle plate, and the method for introducing this nozzle plate into the nozzle channel.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

(10) FIG. 1 shows a liquid dispenser 100 having a nozzle unit 10 according to the invention. This liquid dispenser 100 is to be understood as an exemplary liquid dispenser for a nozzle unit 10. Many other designs of liquid dispensers using nozzle units 10 according to the invention are also conceivable.

(11) The liquid dispenser 100 of FIG. 1 has a pressure reservoir 102 in which liquid is stored before being discharged. A discharge head with a housing 104 is mounted on this pressure reservoir 102. This discharge head has a base 112, and an actuation button 110 that can be depressed relative to the latter. When this actuation button 110 is depressed, it acts on an outlet valve 108 of the pressure reservoir 102 such that liquid flows into the discharge head and reaches the nozzle unit 10. An outlet piece 106, in the present case taking the form of a mouthpiece 106 for example, is provided downstream from the nozzle unit 10. By means of the nozzle unit 10, the inflowing liquid is brought into the form of a spray jet, which is dispensed into the outlet piece 106 and can be inhaled by a user.

(12) FIGS. 2 to 4 and 4A to 4D first illustrate, on the basis of a first illustrative embodiment and variants, the structure of a nozzle unit 10 according to the invention.

(13) FIG. 2 shows the individual components in an exploded view.

(14) As its load-bearing component, the nozzle unit 10 has a plastic carrier 20 which has approximately the shape of a top hat with a brim portion 28 and a cylinder portion 29. The plastic carrier is traversed by a nozzle channel 30 from an inlet side 10A to an outlet side 10B.

(15) A nozzle plate arrangement 50 and a filter 80 are inserted or attached from an inlet side 10A. In the illustrative embodiment of FIGS. 2 to 4, the nozzle plate arrangement 50 is formed solely by a thin nozzle plate 51. In this nozzle plate 51, a multiplicity of nozzle openings 52 are provided in a matrix-like arrangement. In a manner explained in more detail below, the filter 80 is applied to an end face 20A of the plastic carrier 20 pointing in the direction of the inlet side 10A.

(16) FIG. 3 shows the plastic carrier 20 from the opposite side, that is to say the inlet side 10A of the plastic carrier 20. It will be seen here that, on the inside of the circumferential end face 20A, a depression 24 is provided which surrounds the nozzle channel 30 and into which support ribs 26 protrude from the outside.

(17) Referring to FIG. 4, the structure of the nozzle unit 10 can be seen in the assembled state. It will be seen that the nozzle plate 51 has penetrated with its edge region 53 into a nozzle channel wall 31 and is thereby fixed. It will also be seen that the nozzle channel 30 has a shape tapering as a whole in the joining direction 2, with various conical sub-portions being provided.

(18) The filter 80 is positioned on the end face 20A and is welded to the plastic carrier 20 in the region of a circumferential welding point 92. On account of the depression 24, the effective surface area of the filter 80 is very large, in the present case approximately twice as large as the cross section of the nozzle channel 30 at the narrowest point thereof. As a result, the filter 80 can filter comparatively large quantities of liquid without clogging.

(19) The filter 80 can, for example, have a separation limit of 4 m, i.e. can filter out all or almost all of the particles that cannot pass the filter in the case of pores of corresponding size. The stated separation limit of 4 m is very suitable if the nozzle openings 52 have a clear or open cross section of 8 m. This coordination ensures that all constituent parts of the liquid that can pass through the filter 80 can also be dispensed through the nozzle openings.

(20) As is shown in FIGS. 4A to 4C, the filter 80 can be designed in various ways. FIGS. 4A to 4C show variants of the region A indicated in FIG. 4.

(21) In the design according to FIG. 4A, a depth filter is used, i.e. a filter 80 made of a porous and, for example, sintered material which is penetrated by irregular pores, the effect of which is that particles of a certain size cannot penetrate the depth filter, but instead are retained therein.

(22) FIG. 4B shows a design with a membrane filter as filter 80. This has filter openings 82 which have a defined position and shape and which may have been introduced into filter 80 or its filter material 180 by means of a laser beam, for example. Particles that are larger than the cross section of these filter openings cannot penetrate the filter 80 and collect on the upstream side of the filter 80.

(23) FIG. 4C shows a variant in which a membrane filter is likewise used as filter 80. This has a filter membrane 80A similar to that of FIG. 4B. In addition, a carrier layer 80B made of a coarse nonwoven is provided, which gives the filter membrane 80A the necessary stability.

(24) FIG. 4D shows the region B of FIG. 4, in which the nozzle plate 51 bears on the nozzle channel wall 31. It will be seen that the nozzle plate 51 penetrated by nozzle openings 52 has a tapering shape in the edge region 53 and that the outer contour 54 of the nozzle plate 51, on account of the assembly method described below, leads to a compression zone 23 being formed in the region of the nozzle channel wall 31, in which compression zone 23 the plastic material of the plastic carrier 20 is compressed. Downstream and upstream from the nozzle plate 51, the nozzle channel wall 31 projects inward beyond the edge region 53 of the nozzle plate 51, such that the nozzle plate 51 is secured with a form-fit engagement.

(25) FIGS. 5A to 5G show the method for introducing the nozzle plate 51 into the plastic carrier 20.

(26) As is shown in FIG. 5A, starting from a carrier plate 150 having a multiplicity of nozzle plate regions 51 with nozzle openings 52, a nozzle plate 51 is first of all punched out by means of a punching tool 240 and its end-face punching surface 242, which nozzle plate 51, in the present configuration, alone forms the nozzle plate arrangement 50. This nozzle plate 51 is inserted into the plastic carrier 20 from the inlet side 10A, in the joining direction 2, immediately after the punching operation, i.e. without intermediate storage with other nozzle plates.

(27) As will be seen from FIG. 5B, on account of the inlet side 10A having a cross section 40 larger than the outer contour 54 of the nozzle plate 51, said nozzle plate 51 immediately reaches quite deep into the nozzle channel 30 and first comes to lie in a conical sub-portion 36 of the nozzle channel wall 31.

(28) As is illustrated in FIG. 5C, an assembly tool 200 is then pushed into the nozzle channel 30 from above in the joining direction 2. With its outer contour 202, the assembly tool 200 likewise comes into contact with the nozzle channel wall 31 in the conical sub-portion 36. In the course of the continued movement of the assembly tool 200 in the joining direction 2, said assembly tool 200, as can be seen in FIG. 5D, begins to elastically expand the nozzle channel 30.

(29) As a result of this expansion, the nozzle plate 51 also sinks increasingly downward in the joining direction, until it reaches its end position, shown in FIG. 5E, in a second conical sub-portion 38. In the present example, this further movement of the nozzle plate 51 does not require any direct contact with the assembly tool 200. However, in other configurations of the method, provision may also be made that the assembly tool 200 is in contact with the nozzle plate 51 and is thereby able to push the latter deeper into the nozzle channel 30.

(30) Finally, in the manner illustrated in FIG. 5F, the assembly tool 200 is pulled out of the nozzle channel 30 counter to the joining direction 2. The nozzle plate 51 remains in the nozzle channel 30. The nozzle channel wall 31, which in the meantime has expanded elastically, returns to its starting position, although, on account of the nozzle plate 51, it cannot completely reset itself in an annular region 22 in the region of the end position of the nozzle plate 51, such that the compression zone 23 already mentioned, which is shown in FIG. 4D, remains in a circumferential annular region 22. On both sides of this compression zone 23 in the region of nozzle channel portions 32, 34, however, the nozzle channel wall 31 is reset. The nozzle channel wall 31 returns to its initial position to such an extent that the cross sections 33, 35 there are smaller than the outer contour 54 of the nozzle plate 51.

(31) The assembly method described leads to secure attachment of the nozzle plate 51 in the nozzle channel 30. Even external forces during assembly, and pressure peaks during operation, cannot loosen the nozzle plate 51. The remaining elastic compression in the compression zone 23 ensures that the nozzle plate 51 is held securely even in the case of lengthy storage times.

(32) FIGS. 6A to 6C illustrate the application of the filter 80, wherein the method is preferably carried out with nozzle units 10 which are not yet finished and which have been mounted in accordance with the description of FIGS. 5A to 5G.

(33) Referring to FIG. 6A, it will be seen that a filter material 180 is used which can be unwound from a roll, for example. This filter material 180 is placed over the plastic carrier 20 already provided with the nozzle plate arrangement 50, such that, preferably in the context of a continuous process, the plastic carrier 20 is subsequently welded to the filter material 180 by means of a joining stamp 260 and by means of a circumferential joining edge 262 provided therein.

(34) A portion of the filter material 180 is thus obtained on which a large number of plastic carriers 20 with nozzle plate arrangements 50 are thermally fastened. Proceeding from this, in the manner illustrated by FIG. 6B, the filter material 180 is cut all around the end face 20A by means of a cutting tool 280 with a cutting face 282. The nozzle units 10 thus finished, but not yet mounted, can be easily handled in the manner indicated in FIG. 6B. By virtue of the already applied filter 80 and by virtue of the interior of the nozzle units 10 being free from disruptive particles on account of the described production method, and also on account of the secure closure of the nozzle units 10 by the nozzle plates 51, there is no danger of the nozzle units 10 thus finished being contaminated during operation.

(35) FIG. 6C shows once again one of the finished nozzle units 10 with the filter 80 which remains after the cutting process and which is tightly closed in the region of the circumferential welding point 92 by the joining edge 262 of the joining tool 260.

(36) FIGS. 7 and 8 show an alternative design of the nozzle unit 10. A significant difference compared to the nozzle unit 10 of FIG. 4 lies in the design of the nozzle plate arrangement 50. In the present case, this is not only composed of the nozzle plate 51 but additionally comprises a carrier frame 56 made of plastic, which is provided on the upstream side of the nozzle plate 51. The carrier frame 56 can, for example, be injection molded onto the nozzle plate. It has a shape, and in particular an outer contour 58, which allows the edge region 53 of the nozzle plate 51 to be firmly connected to the nozzle channel wall 31 in the manner described. The carrier frame 56 gives the nozzle plate arrangement 50 as a whole a higher intrinsic stability and also reduces the danger of the nozzle plate 51 being damaged by the assembly tool 200 during the assembly process.

(37) FIG. 9 shows an alternative design, in which a clamping element 90 in the form of a clamping ring 90 is provided, which in the present case is provided instead of the welding point 92. Accordingly, the filter 80 here is not cohesively bonded to the plastic carrier 20, and instead it is pressed axially, in an edge-side clamping region 84, against the end face 20A of the plastic carrier by the clamping ring 90 that encompasses the brim portion 28.

(38) In the design in FIG. 10 also, the flat filter 80 is fixed by a clamping element 90 in the form of a clamping ring 90. Here, however, the clamping ring 90 is pushed into a depression of the plastic carrier 20 and, between its outside and the edge of the depression of the plastic carrier 20, clamps the material of the filter 80 radially in an edge-side clamping region 86.

(39) The alternative design in FIG. 11 shows the same basic principle with radial clamping of the filter 80 in the clamping region 86; here, the clamping ring 90 is arranged on the outside of the plastic carrier 20, such that it is an inner surface of the clamping ring 90 which in this case clamps the edge region of the filter 80.

(40) FIG. 12 shows an alternative design to that of FIG. 4, which differs from the latter in that the nozzle plate 51 adopts a curved configuration. Such a curved configuration can be advantageous on account of the diverging orientation of the nozzle openings 52 and produces a spray jet that is fanned out to a greater extent.

(41) To produce such a design, it is possible to press the nozzle plates 51 plastically into a curved shape prior to introduction into the nozzle channel 30 and to carry out the method according to FIGS. 5A to 5E otherwise unchanged.

(42) However, as is shown in FIG. 13, provision can alternatively also be made that the assembly tool 200 has a convexly curved end face 204, and an auxiliary tool 220 is pushed into the nozzle channel 30 from the opposite side. This auxiliary tool 220 has a likewise curved, and in this case concavely curved, end face 224. During assembly, the assembly tool 200 and the auxiliary tool 220 together elastically press the originally flat nozzle plate 51 into a curved shape and bring it to its end position in this elastically deformed state. When the assembly tool and the auxiliary tool 220 are then pulled out of the nozzle channel 30 in opposite directions, this curved shape is at least partially retained.