Patent ID: 12201765

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

FIG.1shows a liquid dispenser100having a nozzle unit10according to the invention. This liquid dispenser100is to be understood as an exemplary liquid dispenser for a nozzle unit10. Many other designs of liquid dispensers using nozzle units10according to the invention are also conceivable.

The liquid dispenser100ofFIG.1has a pressure reservoir102in which liquid is stored before being discharged. A discharge head with a housing104is mounted on this pressure reservoir102. This discharge head has a base112, and an actuation button110that can be depressed relative to the latter. When this actuation button110is depressed, it acts on an outlet valve108of the pressure reservoir102such that liquid flows into the discharge head and reaches the nozzle unit10. An outlet piece106, in the present case taking the form of a mouthpiece106for example, is provided downstream from the nozzle unit10. By means of the nozzle unit10, the inflowing liquid is brought into the form of a spray jet, which is dispensed into the outlet piece106and can be inhaled by a user.

FIGS.2to4and4A to4Dfirst illustrate, on the basis of a first illustrative embodiment and variants, the structure of a nozzle unit10according to the invention.

FIG.2shows the individual components in an exploded view.

As its load-bearing component, the nozzle unit10has a plastic carrier20which has approximately the shape of a top hat with a brim portion28and a cylinder portion29. The plastic carrier is traversed by a nozzle channel30from an inlet side10A to an outlet side10B.

A nozzle plate arrangement50and a filter80are inserted or attached from an inlet side10A. In the illustrative embodiment ofFIGS.2to4, the nozzle plate arrangement50is formed solely by a thin nozzle plate51. In this nozzle plate51, a multiplicity of nozzle openings52are provided in a matrix-like arrangement. In a manner explained in more detail below, the filter80is applied to an end face20A of the plastic carrier20pointing in the direction of the inlet side10A.

FIG.3shows the plastic carrier20from the opposite side, that is to say the inlet side10A of the plastic carrier20. It will be seen here that, on the inside of the circumferential end face20A, a depression24is provided which surrounds the nozzle channel30and into which support ribs26protrude from the outside.

Referring toFIG.4, the structure of the nozzle unit10can be seen in the assembled state. It will be seen that the nozzle plate51has penetrated with its edge region53into a nozzle channel wall31and is thereby fixed. It will also be seen that the nozzle channel30has a shape tapering as a whole in the joining direction2, with various conical sub-portions being provided.

The filter80is positioned on the end face20A and is welded to the plastic carrier20in the region of a circumferential welding point92. On account of the depression24, the effective surface area of the filter80is very large, in the present case approximately twice as large as the cross section of the nozzle channel30at the narrowest point thereof. As a result, the filter80can filter comparatively large quantities of liquid without clogging.

The filter80can, for example, have a separation limit of 4 μm, 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 μm is very suitable if the nozzle openings52have a clear or open cross section of 8 μm. This coordination ensures that all constituent parts of the liquid that can pass through the filter80can also be dispensed through the nozzle openings.

As is shown inFIGS.4A to4C, the filter80can be designed in various ways.FIGS.4A to4Cshow variants of the region A indicated inFIG.4.

In the design according toFIG.4A, a depth filter is used, i.e. a filter80made 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.

FIG.4Bshows a design with a membrane filter as filter80. This has filter openings82which have a defined position and shape and which may have been introduced into filter80or its filter material180by means of a laser beam, for example. Particles that are larger than the cross section of these filter openings cannot penetrate the filter80and collect on the upstream side of the filter80.

FIG.4Cshows a variant in which a membrane filter is likewise used as filter80. This has a filter membrane80A similar to that ofFIG.4B. In addition, a carrier layer80B made of a coarse nonwoven is provided, which gives the filter membrane80A the necessary stability.

FIG.4Dshows the region B ofFIG.4, in which the nozzle plate51bears on the nozzle channel wall31. It will be seen that the nozzle plate51penetrated by nozzle openings52has a tapering shape in the edge region53and that the outer contour54of the nozzle plate51, on account of the assembly method described below, leads to a compression zone23being formed in the region of the nozzle channel wall31, in which compression zone23the plastic material of the plastic carrier20is compressed. Downstream and upstream from the nozzle plate51, the nozzle channel wall31projects inward beyond the edge region53of the nozzle plate51, such that the nozzle plate51is secured with a form-fit engagement.

FIGS.5A to5Gshow the method for introducing the nozzle plate51into the plastic carrier20.

As is shown inFIG.5A, starting from a carrier plate150having a multiplicity of nozzle plate regions51′ with nozzle openings52, a nozzle plate51is first of all punched out by means of a punching tool240and its end-face punching surface242, which nozzle plate51, in the present configuration, alone forms the nozzle plate arrangement50. This nozzle plate51is inserted into the plastic carrier20from the inlet side10A, in the joining direction2, immediately after the punching operation, i.e. without intermediate storage with other nozzle plates.

As will be seen fromFIG.5B, on account of the inlet side10A having a cross section40larger than the outer contour54of the nozzle plate51, said nozzle plate51immediately reaches quite deep into the nozzle channel30and first comes to lie in a conical sub-portion36of the nozzle channel wall31.

As is illustrated inFIG.5C, an assembly tool200is then pushed into the nozzle channel30from above in the joining direction2. With its outer contour202, the assembly tool200likewise comes into contact with the nozzle channel wall31in the conical sub-portion36. In the course of the continued movement of the assembly tool200in the joining direction2, said assembly tool200, as can be seen inFIG.5D, begins to elastically expand the nozzle channel30.

As a result of this expansion, the nozzle plate51also sinks increasingly downward in the joining direction, until it reaches its end position, shown inFIG.5E, in a second conical sub-portion38. In the present example, this further movement of the nozzle plate51does not require any direct contact with the assembly tool200. However, in other configurations of the method, provision may also be made that the assembly tool200is in contact with the nozzle plate51and is thereby able to push the latter deeper into the nozzle channel30.

Finally, in the manner illustrated inFIG.5F, the assembly tool200is pulled out of the nozzle channel30counter to the joining direction2. The nozzle plate51remains in the nozzle channel30. The nozzle channel wall31, which in the meantime has expanded elastically, returns to its starting position, although, on account of the nozzle plate51, it cannot completely reset itself in an annular region22in the region of the end position of the nozzle plate51, such that the compression zone23already mentioned, which is shown inFIG.4D, remains in a circumferential annular region22. On both sides of this compression zone23in the region of nozzle channel portions32,34, however, the nozzle channel wall31is reset. The nozzle channel wall31returns to its initial position to such an extent that the cross sections33,35there are smaller than the outer contour54of the nozzle plate51.

The assembly method described leads to secure attachment of the nozzle plate51in the nozzle channel30. Even external forces during assembly, and pressure peaks during operation, cannot loosen the nozzle plate51. The remaining elastic compression in the compression zone23ensures that the nozzle plate51is held securely even in the case of lengthy storage times.

FIGS.6A to6Cillustrate the application of the filter80, wherein the method is preferably carried out with nozzle units10which are not yet finished and which have been mounted in accordance with the description ofFIGS.5A to5G.

Referring toFIG.6A, it will be seen that a filter material180is used which can be unwound from a roll, for example. This filter material180is placed over the plastic carrier20already provided with the nozzle plate arrangement50, such that, preferably in the context of a continuous process, the plastic carrier20is subsequently welded to the filter material180by means of a joining stamp260and by means of a circumferential joining edge262provided therein.

A portion of the filter material180is thus obtained on which a large number of plastic carriers20with nozzle plate arrangements50are thermally fastened. Proceeding from this, in the manner illustrated byFIG.6B, the filter material180is cut all around the end face20A by means of a cutting tool280with a cutting face282. The nozzle units10thus finished, but not yet mounted, can be easily handled in the manner indicated inFIG.6B. By virtue of the already applied filter80and by virtue of the interior of the nozzle units10being free from disruptive particles on account of the described production method, and also on account of the secure closure of the nozzle units10by the nozzle plates51, there is no danger of the nozzle units10thus finished being contaminated during operation.

FIG.6Cshows once again one of the finished nozzle units10with the filter80which remains after the cutting process and which is tightly closed in the region of the circumferential welding point92by the joining edge262of the joining tool260.

FIGS.7and8show an alternative design of the nozzle unit10. A significant difference compared to the nozzle unit10ofFIG.4lies in the design of the nozzle plate arrangement50. In the present case, this is not only composed of the nozzle plate51but additionally comprises a carrier frame56made of plastic, which is provided on the upstream side of the nozzle plate51. The carrier frame56can, for example, be injection molded onto the nozzle plate. It has a shape, and in particular an outer contour58, which allows the edge region53of the nozzle plate51to be firmly connected to the nozzle channel wall31in the manner described. The carrier frame56gives the nozzle plate arrangement50as a whole a higher intrinsic stability and also reduces the danger of the nozzle plate51being damaged by the assembly tool200during the assembly process.

FIG.9shows an alternative design, in which a clamping element90in the form of a clamping ring90is provided, which in the present case is provided instead of the welding point92. Accordingly, the filter80here is not cohesively bonded to the plastic carrier20, and instead it is pressed axially, in an edge-side clamping region84, against the end face20A of the plastic carrier by the clamping ring90that encompasses the brim portion28.

In the design inFIG.10also, the flat filter80is fixed by a clamping element90in the form of a clamping ring90. Here, however, the clamping ring90is pushed into a depression of the plastic carrier20and, between its outside and the edge of the depression of the plastic carrier20, clamps the material of the filter80radially in an edge-side clamping region86.

The alternative design inFIG.11shows the same basic principle with radial clamping of the filter80in the clamping region86; here, the clamping ring90is arranged on the outside of the plastic carrier20, such that it is an inner surface of the clamping ring90which in this case clamps the edge region of the filter80.

FIG.12shows an alternative design to that ofFIG.4, which differs from the latter in that the nozzle plate51adopts a curved configuration. Such a curved configuration can be advantageous on account of the diverging orientation of the nozzle openings52and produces a spray jet that is fanned out to a greater extent.

To produce such a design, it is possible to press the nozzle plates51plastically into a curved shape prior to introduction into the nozzle channel30and to carry out the method according toFIGS.5A to5Eotherwise unchanged.

However, as is shown inFIG.13, provision can alternatively also be made that the assembly tool200has a convexly curved end face204, and an auxiliary tool220is pushed into the nozzle channel30from the opposite side. This auxiliary tool220has a likewise curved, and in this case concavely curved, end face224. During assembly, the assembly tool200and the auxiliary tool220together elastically press the originally flat nozzle plate51into a curved shape and bring it to its end position in this elastically deformed state. When the assembly tool and the auxiliary tool220are then pulled out of the nozzle channel30in opposite directions, this curved shape is at least partially retained.