APPLICATOR MANUFACTURED IN ONE PIECE WITH INTERLEAVED BRISTLES

Abstract

Cosmetics applicator 1, in particular, having the form of a mascara applicator with a cap 3 forming a grip area 2 for tight closing of a cosmetics reservoir, which as one piece turns into a shaft 4 protruding from it which shaft 4, in turn, as one piece forms a handle segment 5 and a bristle-carrying segment 6 with the bristle-carrying segment 6 as such having a hollow structure and supporting injected bristles 7 which are integrally connected with a plastic core 8 covering or filling the inside of the bristle-carrying segment 6 through the wall of the bristle-carrying segment 6 with the cap 3 and the shaft 4 preferably consisting of a different plastic material than the plastic core 8 and the bristles 7.

Description

FIELD OF THE INVENTION

The invention concerns an applicator with a handle, a shaft and bristles which can be manufactured particularly rationally as well as a procedure for the production of such an applicator.

BACKGROUND OF THE INVENTION

According to the state of the art, the consistent approach used so far is that for the purpose of the production of cosmetics applicators a handle, a shaft and bristle carrier with bristles protruding radially from it are manufactured separately and assembled in a subsequent step.

This procedure is demanding. At the same time, this procedure is not unproblematic in terms of hygiene because a narrow gap, which cannot be fully sealed in practice, remains, in particular, in the area in which the coupling section of the bristle carrier is mounted on the shaft. Residues of the cosmetic products can accumulate in this gap and under unfavourable circumstances this could promote the accumulation of fungi or bacteria.

This invention pursues the aim of improving this situation.

SUMMARY OF THE INVENTION

Such a cosmetics applicator, which is designed, in particular, as a mascara applicator, has a cap designed with a grip area on the outside. The cap is used to tightly close a cosmetics reservoir. The cap moves into a shaft protruding from it in one piece. The shaft forms a handle segment and integrated into it a bristle-carrying segment, i.e. the handle segment and the bristle-carrying segment seamlessly merge into one another and they are executed as a one-piece component. In this respect, bristles protrude from the bristle-carrying segment with these bristles being formed as an integral component of the bristle-carrying segment by inseparably interlocking and welding the bristle-forming material with the bristle-carrying segment. This connection is achieved by the special design of the bristle-carrying segment. This is because the bristle-carrying segment as such is formed as a structure hollow on the inside and it carries injected bristles which are integrally connected with a plastic core covering the inside of the bristle-carrying segment through the wall of the bristle-carrying segment. In this respect, the cap and the shaft (consisting of the handle segment and the bristle carrier) preferably consist of a different plastic material than the plastic core and the bristles. Ideally, these two plastic materials are selected so that they become welded in the context of the injection of the bristles.

According to the invention, the bristles, the handle and the cap form a one-piece component as a result. The working step of inserting a coupling piece for a bristle carrier equipped with bristles into a hollow shaft, which has been required so far, and the subsequent permanent mounting between the said two individual components on each other is no longer necessary. This significantly reduces the costs of the applicator according to the invention because it can now be produced through two consecutive injection moulding processes which can be carried out fully automatically one after the other.

Moreover, the applicator according to the invention is also advantageous under consideration of hygienic aspects because there are no joints which result from joining anywhere and into which the cosmetics product could penetrate to permanently stay there and form a focus of germs there over time.

Wherever two different plastics have been considered so far, the preferable solution is that the first plastic compound which forms the bristles consists of a plastic which after cooling is more flexible and/or has better “bend-recovery characteristics” than the second plastic compound which preferably forms the cap and/or the shaft. A plastic which is particularly suitable for providing the first plastic compound is the plastic type commercially available under the trademark “Grilflex”®. Polypropylene (PP) is particularly suitable as the second plastic compound.

The applicator according to the invention can be produced very efficiently because including the bristles it consists of only a single piece which can be produced in two injection moulding steps on one and the same machine. As a result, the separate production of individual components and the subsequent assembly of one on the other are no longer necessary.

Moreover, under hygienic aspects such an applicator also has better properties. There is no gap between the shaft and the coupling piece of some carrier which is equipped with bristles. Such a gap does not exist in the cosmetics applicator according to the invention because it is executed as a one-piece structure.

Moreover, there are no gaps which might be cause for concern in the area where the bristles are installed.

This also applies if the bristles are integrally connected with a plastic core covering the inside of the bristle-carrying segment and which locally penetrate the wall of the bristle-carrying segment. Because of this, there is also a particularly close connection between the second plastic material which forms the bristles and the plastic material filling the inner part of the bristle-carrying segment and the tubular bristle-carrying segment everywhere. No gaps in which bacteria or fungi might accumulate remain anywhere.

Preferably, the cosmetic applicator is designed so that the cavity of the bristle-carrying segment has an open end on the face side of the bristle-carrying segment facing away from the cap. In this way, the plastic compound which locally penetrates the wall of the bristle-carrying segment and which is to form the bristles can be injected particularly well without the formation of bubbles.

Ideally, the bristle-forming segment is designed so that it, at least, essentially has a constant wall thickness which should ideally be ≦1 mm or, even better, ≦0.75 mm. The solution under which the hollow segment of the shaft has a wall thickness of ≦0.3 mm or, even better, of ≦0.25 mm is preferred, in particular.

In the context of a preferred embodiment it is intended that the shaft segment be designed, at least, with a partially hollow structure and with a separating segment on the inside which separating segment separates its cavity from the cavity of the bristle-carrying segment in a pressure tight manner so that even under the influence of an injection pressure of several hundred bars it is not penetrated.

Ideally, it is planned to have the shaft segment executed as a solid structure on the side facing away from the handle and in this way to form a separating segment which covers approximately ⅕ to ½ of the total length of the shaft segment and ensures reliable sealing. In this way, the shaft segment also seals reliably if the cycle times are kept relatively short and if the shaft segment which is injection-moulded together with the cap has not completely cooled down at the time at which the bristles are injected in a second step.

A particularly reliable and stable construction results if the wall thickness of the bristle-carrying segment increases directly before the transition of the bristle-carrying segment into the shaft segment. Preferably, the design should be for the wall thickness of the bristle-carrying segment to increase on the inside.

In the framework of a particularly favourable design, an alternative option is provided for under which the shaft is executed as a consistently hollow structure on the inside and forms a duct through which the plastic compound injected for the purpose of the production of the bristles can flow up to the area of the cap and, preferably, up to the area of the outer circumference of the cap in the context of the production. In this way, a special design of the cap can be achieved, preferably in the area of its grip area, particularly efficiently, i.e. in one working step together with the injection of the bristles. Typically, as a result of this, the grip area of the cap is equipped with one or several surface areas which consist of the softer material of the bristles (compared with the joint plastic material of the cap and of the shaft segment) and which, therefore, improve the haptic impression of the grip area—for example, by giving the grip area a better grip and making it less likely to slip from the user's hand, e.g. if the applicator is used with wet/numb fingers after the user has taken a shower.

A solution in which the outer diameter (OS) of the shaft segment is essentially or consistently bigger than the outer diameter (OB) of the bristle-carrying segment has proved to be particularly favourable. In this respect, the OS/OD ratio should preferably be ≦0.8 and, ideally, it should be ≦0.7. In this way, a situation is reliably prevented in which the applied bristles are overloaded upon passing the scraper, which would sooner or later damage the bristles, as a result.

In the framework of another possible further embodiment of the invention, there are plans for the cap to be executed without a thread and for it to be designed so that it can be frictionally engaged on the neck of an appertaining reservoir for a tight seat of the cosmetics applicator and/or positively locked in place on the cosmetics reservoir.

Another preferred embodiment provides for a fastening element which is provided for on the cap which fastening element is designed as an external thread.

In this context, the preferred solution is that a fastening element on the side of the cap should be provided for which is designed so that in combination with a corresponding fastening element on the side of the container it forms an applicator quick-release fastener which is designed as a bayonet coupling or preferably as multi-start short threads and dimensioned so that the fastening element on the side of the cap and on the side of the container can be moved from a completely closed position to a position in which the two elements are no longer connected to each other in the direction of the applicator's longitudinal axis with a rotation movement ≦ of ⅜ of a turn and, even better, with a rotation movement ≦ of ¼ of a turn.

Preferably, the short thread is to be executed as a steep thread with a gradient angle μ of preferably more than 5°. With the help of such a short thread, a reliably sufficient sealing pressure can be achieved between the applicator and the cosmetics reservoir allocated to it (in a parallel direction to the longitudinal axis of the applicator) in spite of the fact that the thread is only turned slightly in the locking direction until the full locking position is reached.

A particularly preferred embodiment comprises the provision of an additional holder which holds the fastening element on the side of the cap and the fastening element on the container which interacts with it together as soon as they have reached their fully closed position, in addition to the existing sliding friction on the thread. In this context, the additional support is preferably a catching edge which, if it is travelled over, makes a tongue mounted on the container's fastening element on one side spring out radially in order to snap into place in a catching recess in the area of the tongue.

Ideally, the short thread should be designed as a two-start thread whose threads are positioned in diametrically opposite positions and which are kept so short in the circumferential direction and whose gradient is selected so that the cap with the short thread can be formed from the injection mould in such a way that the two halves of the mould which e.g. reflect the short thread can be moved apart by a movement which is essentially perpendicular to the longitudinal axis of the applicator in order to form the applicator or the segment forming the short thread. In this context, this is not only a procedural provision but primarily a definition regarding the physical structure of the short thread.

In the framework of another preferred embodiment, it is envisaged that the predominant share of the cap should be formed from a number of fins which should radially protrude from a joint centre or, even better, a number of fins which should essentially be positioned next to each other in parallel. This preferred embodiment is quite important for the application according to the invention since such a design of the cap has a very positive effect on their demoulding characteristics compared with the production of the cap as a tube segment which defines an enclosed space in the circumferential direction and, therefore, requires a slider on the side of the injection mould.

Expediently, the cap has a solid plate on its end facing the applied bristles which plate moves into the shaft as one piece on its own face side and merges into the fins on the other face side. A very stable locking device can be formed on this plate without bringing about an accumulation of material, which might e.g. become visible through the formation of depressions on which the surface visibly bends inwards in the course of the cooling of the material.

Another possible embodiment which is used as an alternative consists of the shaft segment being connected with a plate which preferably extends in a radial direction in one piece on the end facing the cap. The plate in turn merges into the cap in one piece.

In this process, the cap can have the structure of a single-layer tube which is open on both face sides and formed from a single perimeter wall. On its outer wall, it forms an operating area which is directly accessible for the final consumer. In this context, the tube should preferably have an essentially consistent wall thickness.

For this embodiment, it has been proven to be expedient for the plate to have an opening which connects the cavity of the shaft segment with the subsequent cavity defined by the cap in the circumferential direction. This is because a consistently solid shaft has proven to be inappropriate on account of the high material consumption and the long cooling times.

This invention has the further task of providing a procedure for the rational production of an applicator.

Accordingly, the following procedure is proposed:

In a first step of the procedure, a workpiece also referred to as the “main component of the applicator” hereinafter, which comprises a cap for tight sealing of a cosmetics reservoir forming a grip area on its outer circumference which merges into a shaft protruding from it in one piece, is manufactured, preferably, by using an injection moulding procedure. In this context, the shaft forms a handle segment and a bristle-carrying segment as one piece. In a second production step, the bristles are injected on the bristle-carrying segment. Preferably, the approach should be that the bristle-forming plastic compound is injected into the hollow interior of the bristle-carrying segment. In this context, the injection pressure has to be selected to be high enough for the bristle-forming plastic compound to locally penetrate the wall of the bristle-carrying segment in an outward direction wherever the wall is hollow because it bridges a bristle-forming cavity which is initially not filled. On the other hand, the injection pressure must be selected so as to be low enough to ensure that the bristle-forming plastic compound does not penetrate the still warm solid separating segment of the shaft, which prevents the ingress of the bristle-forming plastic compound in the direction of the cap.

It has been proven to be particularly favourable if the bristle-carrying segment 6 is formed from the first additional mould reflecting it after injection moulding of the workpiece while the rest of the workpiece remains in the mould cavity of the main mould used for its production. Afterwards, a second additional mould completely enclosing the outer circumference of the bristle-carrying segment 6 is created which has the bristle-forming cavities and is brought close for positioning on the main mould.

In this respect, it has been proven to be particularly favourable to turn the main mould after moulding of the bristle-carrying segment 6 from the first additional mould and to only insert the bristle-carrying segment 6 into the second additional mould after this. In this way, a particularly compact mould can be produced in which the two steps can be carried out.

Ideally, the approach should be that the joint is positioned between the main mould and the first additional mould at a level which transects the solid separating segment of the shaft. This ensures that the corresponding joint again fulfils its function without any problems after the second additional mould is positioned.

Further advantages, effects and design options result on the basis of the description of an execution example outlined below with the help of the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the main component of the applicator before the installation of the brush.

FIG. 2 shows a sectional view of the finished applicator along its longitudinal axis L.

FIG. 3 shows an individual bristle and illustrates what the term “bristle” means in the context of the invention.

FIG. 4 shows an enlarged detail of the wall of the bristle-carrying segment 6 and the plastic mould which forms the individual bristles 7 and fills the centre of the bristle-carrying segment 6.

FIG. 5 shows the arrangement of the mould which is used to produce the main component of the applicator by injection moulding.

FIG. 6 shows how the main component is partly formed after injection-moulding and subsequent cooling in order to insert it into the second additional mould in a subsequent step.

FIG. 7 shows the moment at which the second injection mould was positioned meaning that the ensemble is now ready for the execution of the second injection moulding process during which the bristles are produced.

FIG. 8 shows a second, modified execution example of the invention.

FIG. 9 shows a third execution example of the invention in a sectional view along the longitudinal axis of applicator L with this third execution example in the bristle-carrying segment corresponding to the execution examples outlined above.

FIG. 10 shows a lateral view of the third execution example.

FIG. 11 shows a perspective view of the third execution example.

FIG. 12 again illustrates the specific design of the cap from the third execution example.

FIG. 13 illustrates the part of the fastening to be mounted on the cosmetics reservoir and forms the counterpart of the part of the fastener which is formed as an element of the cap in FIG. 12.

FIG. 14 shows a sectional view with a circularly curved section through the central part of the mould or one half of it.

FIG. 15 illustrates an optional design of the cap which can be moulded particularly favourably.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following can be stated with regard to the first execution example illustrating the invention:

FIG. 2 shows a finished cosmetics applicator according to the invention, while FIG. 1 shows the one-piece main component of the applicator from which the finished cosmetics applicator is produced by injecting bristles.

The applicator consists of a cap 3, which is connected with a shaft 4 in one piece, cf. FIG. 2. The shaft 4 has a longitudinal axis L. Shaft 4, in turn, is divided into two segments with different functions and, in one piece, consists of a shaft segment 5 and a bristle-carrying segment 6, cf. FIG. 1. The shaft segment 5 ensures a sufficient spatial distance between the brush and the grip area formed by the cap 3, which is required in order to give the applicator the application characteristics required by the users. The bristle-carrying segment 6 is used to anchor the brush which permits the cosmetics product to be applied and which preferably consists of at least 300 bristles, which are only shown rudimentarily in FIG. 2. The segments mentioned are formed by a uniform injection-moulded part referred to as the “main component”; i.e. they are jointly formed as a one-part component (in this respect, reference is made to FIG. 1 which shows the main component). Such a main component can be produced very rationally. After it has been equipped with a brush in the next procedural step, the applicator is finished. A complex assembly of a brush part on a shaft is not required.

As FIGS. 1 and 2 show, cap 3 is preferably formed by a tube which is open on both end faces, which tube ideally has an expanding diameter in the direction of its side facing away from the bristles installed. Here, the interior of the cap is equipped with a thread 13 for screwing it into the reservoir container which is not shown on the side facing the applicator. In the preferred embodiment the thread is replaced by one or several snap-in devices (a snap-in bead covering all or a part of the circumference), which decisively facilitates shaping.

A plate 11 is preferably used as the connecting link between the shaft 4 or its handle segment 5 and cap 3. This plate essentially extends in a radial direction relative to the longitudinal axis L. The plate is preferably positioned so that it divides the tube forming the cap 3 into two segments with the length of the segment facing the applicator accounting for approximately ⅓ of the length of the segment facing away from the applicator. The plate preferably forms a sealing surface which is designed for positioning on the face ring surface of a bottleneck.

In this context, the plate 11 preferably has a central plate opening 12. The plate opening 12 permits a mould core to reach through the plate which ensures that the shaft 4 can be given a hollow inside structure in the area of its handle segment 5. The plate 11 is connected with the cap 3 in one piece in the area of the plate's external circumference. In the area of its internal circumference, it is connected in one piece with the shaft 4—or more precisely with its handle segment 5. The wall thickness of the plate 11 in the direction which runs parallel to the longitudinal axis L usually corresponds to, at least, the wall thickness of cap 3. Compared with this, the wall thickness of the part of the handle segment 5 which is given a hollow structure is preferably bigger, cf. FIG. 1. However, the handle segment 5 does not have a hollow structure along its entire length. Instead, it should preferably be designed so that its distal end, i.e. the end facing away from the cap 3 has a solid structure. Preferably, the handle segment 5 has a solid structure at least along a length accounting for at least ⅙ or, even better, for at least ¼ of its total length. This reliably prevents the plastic compound injected in order to form the bristles from penetrating the barrier into the handle segment which is still warm as a result of short cycle times and from moving in the direction of the cap 3.

Ideally, the outer diameter of the handle segment 5 declines in the area of its distal end facing away from the cap 3, which is also shown in the figures.

The distal end of the handle segment 5 is followed by the bristle-carrying segment 6 in one piece which is illustrated, in particular, in FIG. 1. The bristle-carrying segment 6 is initially a tube which is hollow on the inside and consists of the same material as the handle segment 5. However, the wall thickness of the bristle-carrying segment 6 is usually lower; it preferably amounts to, at maximum, 60% and, even better, less than 40% of the wall thickness of the handle segment 5. On the transition between the handle segment 5 and the bristle-carrying segment 6, the wall thickness of the bristle-carrying segment 6 preferably increases slightly, preferably, towards the inside.

The bristles 7 which are essentially radially positioned pointing outward protrude from the bristle-carrying segment 6 the way this is indicated in FIG. 2. In reality, the distance between the bristles is smaller and the number of bristles is significantly bigger than shown because, usually, at least 300 bristles of the type discussed here will be found on the applicator and, occasionally, even more than 600 bristles can be provided for. The effective diameter of the preferably essentially round bristles in the area of their foot typically lies in a range of between 0.1 mm and 1 mm, preferably in the range between 0.1 mm and 0.4 mm.

The bristles 7 are injected bristles; this means these are bristles which receive their shape through the corresponding cavity in an injection mould into which they are usually injected at high pressure, which will be discussed in more detail shortly. The injection moulding procedure according to the invention also gives the bristles their decisive physical application properties because in injection-moulded bristles which have been produced according to the procedure material for the invention, the polymer chains forming the bristle display a special alignment in parallel with the longitudinal axis of the bristle.

In this document, the term “bristles” preferably refers to application devices like those shown in FIG. 3. Each of these bristles preferably has an essentially tapered sleeve. Usually, a taper angle α of between 0.5° and 2.5° is found, cf. FIG. 3. On account of the alignment of the polymer chain, which has already been discussed, these bristles are usually particularly flexible. Therefore, under the influence of the forces which occur in applying the product as provided for they can typically be guided so that their tip moves away from the rest position by a distance of S which corresponds to, at least, three times or, even better, at least five times the diameter of the bristle foot without permanently distorting the bristle.

The bristles 7 are injection-moulded by injecting the bristle-forming plastic compound into the cavity 9 of the bristle-carrying segment 6 under a correspondingly high pressure. This bristle-forming plastic compound which is preferably a plastic compound which differs from the compound from which the main component has been produced penetrates the wall of the bristle-carrying segment 6 at all those points at which there is an empty, bristle-forming cavity in a radial direction behind the wall of segment 6 carrying the bristles. This creates bristles which reach through the wall of the bristle-carrying segment 6 and are connected with the solid core, which fills the cavity 9 of the bristle-carrying segment 6 in a finished brush and is welded to it, in one piece, cf. FIG. 4. As a result, the plastic compound which forms the bristles and the plastic which forms the bristle-carrying segment 6 become very firmly joined. No microscopic joints, which might promote colonisation by fungi or bacteria, remain open. Ideally, the plastic compound forming the bristles should consist of a plastic which is more elastic and/or has a lower Shore hardness than the plastic of which the main component of the applicator shown in FIG. 1 consists.

The process of the production procedure for the applicator according to the invention is best illustrated with the help of FIG. 5, 6 or 7.

In a first procedural step, the main component is injection-moulded as a one-piece component. To this end, a multi-piece mould will be used. The mould consists of a main part of the mould 14, the first slider 15, the first mould side part 16a for shaping the bristle-carrying segment 6 and the second slider 17 which serves the same purpose. The second slider 17 is guided in a sealing position in the first mould side part 16a. It is remarkable that the joint between the main part of the mould 14 and the first mould side part 16a should preferably be at a level which transacts the handle segment 5 where it is solid.

This way, a particularly good sealing effect can be ensured. The plastic compound which forms the main component is injected into the mould—preferably from the side on which the first slider 15 is located.

As soon as this plastic compound has sufficiently cooled, the second slider 17 is preferably moved first and then the first mould side part 16a is removed. Ideally, the first mould side part 16a is executed as a multi-piece part so that the individual components of the mould side part 16a can be pulled apart into different directions as is roughly indicated by the arrows 18 and 19. The main component is preferably not shaped any further at this stage of the procedure which means that the other components of the mould remain in their relative position to each other.

The components of the injection mould which still contain the main component at this point are preferably turned in order to bring the bristle-carrying segment 6 to the side of the injection point and in order to be able to combine the surrounding mould with the injection point later on.

The area of the main component which is released through the removal of the first mould side part 16a is now inserted into a second mould side part 16b as is shown in FIG. 7. This second mould side part 16b preferably also consists of several components which can be driven up to the main components relative to each other in a radial direction and/or removed from it again. The decisive fact is that this second mould side part 16b is equipped with cavities 20 for the formation of the bristles the way this is shown in FIG. 7 in a grossly simplified manner.

These cavities 20 are still empty initially and their orifices are initially laid through the wall of the bristle-carrying segment 6. In the next step, the bristle-forming plastic compound is injected into the cavity 9 of the bristle-carrying segment 6 from the side of arrow E. The plastic compound exerts such a high pressure on the wall of the bristle-carrying segment 6 from the inside that the plastic compound finally penetrates the wall of the bristle-carrying segment 6 wherever the wall bridges the orifice of a bristle-forming cavity 20. This way the plastic compound is injected into the bristle-forming cavities. As soon as this has happened, we have to wait until this second plastic compound has set to such a degree that it retains its shape. Then, the finished applicator is fully shaped.

In the example of this embodiment, shaping is effected in such a manner that the second mould side part 16b is segmented into a pie-like structure so that the individual parts of the mould side part 16b can be moved apart in a radial direction in order to ensure that the bristles can be shaped without tearing. After that, the first slider 15 is moved. If there is an internal thread on the cap, this is now disengaged through a screwing movement of the entire applicator with the main part, whereupon the two halves of the mould of the upper part of the mould will be moved apart vertically to the longitudinal axis L of the applicator so that the finished applicator can be removed without damaging the applied bristles.

The decisive point is that you get a completely finished applicator in one go by using this procedure without having to remove individual components from the injection moulding system and transporting them to another station in order to assemble them there.

A second execution example of the invention is shown in FIG. 8.

This execution example corresponds to the first execution example which has just been described in detail to the full extent so that what has been stated there also applies to this second execution example unless stated differently in the differences outlined below.

The second execution example is characterised by the fact that, in this embodiment, the shaft 4 is hollow on the inside throughout its entire length. As a result, and unlike the first execution example, the second execution example does not have a separating segment 10 which is executed as a solid structure.

In this way a duct can be created via which the second plastic compound which is injected in order to form the bristles can flow through the shaft 4 all the way into the area of the cap 3. Preferably, the second plastic compound can even flow into an area of the outer circumference of the cap and, for example, forms a haptically and/or visually particularly appealing grip area there.

In this way a grip area with a particularly advantageous structure can be created very efficiently (i.e. in a single step together with the injection of the bristles) on the cap.

Of course, the injection moulds used to this end have to be slightly modified which also has an impact on the execution of the process.

In this case too, the approach comprises injection moulding of the main component as a one-piece component in a first step of the procedure. To this end, the injection mould, which was already shown in FIG. 5 and which consists of the main part of the mould 14, the first slider 15, the first additional mould part 16a and the second slider 17, is used. The decisive difference is that the first slider is shaped so that it sits tightly against the face side of the second slider 17 on its face side facing away from the cap in order to ensure that this way the shaft 4 is formed with a consistently hollow structure throughout.

As soon as the main component has been fully injection-moulded as a one-piece component, the first additional mould part 16a is removed as has already been explained in connection with FIGS. 5 to 7. In addition, however, the first slider 15 is also moved and replaced by a first slider 15a which forms the cavity that is also to be filled with the second plastic compound which also forms the bristles in the subsequent injection moulding procedure in order to create the improved grip area on the cap in this way.

Otherwise, the procedure corresponds to the one already outlined for the first execution example.

On principle, equipping the cap 3 of the applicator which is a one-piece component according to the invention with for example the conventional internal thread shown in FIGS. 5 to 7 is not excluded.

As has already been described above, however, shaping of the fully injection-moulded applicator is quite demanding if such a conventional internal thread is used. Unscrewing of the segment of the cap equipped with the internal thread as described is demanding but it does not pose an insurmountable problem. This is because the need for “unscrewing” a cap produced by injection moulding and equipped with an internal thread from the injection mould by repeatedly turning it around its own axis constitutes the state of the art in many cases (in the case of every bottle cap with a complex design). Such unscrewing can be ensured with corresponding handling systems.

However, in order to simplify shaping caps which do not have an internal thread but are dimensioned so as to ensure that they frictionally interlock with the neck of the cosmetics reservoir adapted accordingly are preferably used in the framework of the invention.

However, especially in the case of high-quality cosmetics, there is demand for providing a form-fittingly locked cap in spite of this since such a cap provides better protection against inadvertent opening or inadvertent incomplete locking of the cosmetics unit resulting in the subsequent drying-up of the cosmetics product. In order to be able to satisfy this demand in connection with an applicator rationally produced in one piece the use of the special short threaded cap which is shown in FIGS. 9 to 12 and 14 and which is to be described in more detail below is particularly advantageous.

As can best be seen with the help of the FIGS. 10, 11 and 12, the cap according to the invention or the short-threaded fastening device are characterised by one form-fitting element each on diametrically opposite sides, preferably in the shape of a hook and ideally having the shape of a thread which can preferably be moved from a fully closed to a fully open position on the finished unit through a rotation of less than ⅜ of a turn and ideally through a rotation of less than ¼ of a turn.

In other words:

The feature of this execution is that the thread on the cap is not executed as an internal thread but as an external thread. Basically the same applies to a bayonet coupling which might be provided for instead of the thread.

Executing the thread in this sense so that its thread groove is accessible from the outer surface of the circumference of the cap as is shown in FIG. 12 is preferred in particular. In this case, the actual effective area of the thread is not formed as a groove between neighbouring elevations on the surface of the inner circumference of the cap. Instead, the effective area of the thread on each side is formed by the side wall essentially extending in a radial direction of a single slot which extends from the outer surface of the circumference of cap 3 downwards in a radial direction along a helix. A thread formed with a mirror inverted structure on the cosmetics reservoir reaches into this slot (cf. again FIG. 12 and FIG. 13, which is to be explained in more detail later).

The decisive point in such a design of the thread is that the applicator can be shaped without having to unscrew the thread section of its cap from the injection mould first by turning the newly injection-moulded applicator several times around its own longitudinal axis L. Instead, the short thread according to the invention permits the separation of the mould in one level which coincides with the longitudinal axis L of the applicator in such a way that one part of the mould shapes the slot running along a helix, while the other part of the mould shapes the opposite slot running along a helix. In this respect, reference can be made to FIG. 14 which shows (in a lateral sectional view) how it shapes the slot allocated to it. If we inspect FIGS. 14 and 12 more closely, we understand that the upper part of the main mould 14 which forms the thread can be lifted off from it by means of a movement aligned to be vertical to the longitudinal axis L of the applicator and to the drawing level without having to unscrew the thread section of the applicator from the mould first. In the same way, the lower part of the mould which is not shown in FIG. 21 can, of course, also be lifted off in the opposite direction.

The corresponding counterpart of the thread on the cosmetics reservoir is shown in FIG. 13.

The multi-start (i.e. in the present case: two-start) thread which is formed from the threads 31a and 31b (on the part of the fastener on the container) or from the threads 32a and 32b is well visible in FIGS. 12 and 13. In this case, the respective area which is closed on three sides, i.e. upwards, downwards and in a circumferential direction and with which the fastening element can exercise a closing force on the other fastening element is referred to as a thread. Moreover, it is also easy to see that every thread is preceded by a free screw surface 33a and 33b (on the side of the fastener on the container) and 34a and 34b (on the side of the fastener on the applicator). The term “precede” refers to the closing direction.

The thread is executed as a steep thread, i.e. the gradient μ of each of the threads is at least 5° compared with the horizontal level with a gradient of, at least, 7° compared with the horizontal level being even better, cf. FIG. 13. In an ideal case, at least 8° compared with the horizontal level are selected.

As is also shown clearly in FIGS. 12 and 13, catching recesses 35 are provided for, preferably, in the area (of at least one thread) of the threads and edges into which the corresponding edges 36 of the other fastening elements slide as soon as the fastening elements have reached their fully closed position relative to each other. These catching recesses 35 and the appertaining edges 36 form additional supports which hold the two fastening elements on each other via positive form locking, in addition to the existing thread friction.

The characteristic feature of the thread shown in FIG. 13 is that the thread is worked into a hollow cylindrical segment of the fastening elements that the free screw areas form the narrow face-side boundary surfaces of the hollow cylindrical segment and the two threads 31a and 31b fully penetrate the wall of the hollow cylindrical segment in a radial direction, i.e. that they each form a “window” into the wall of the hollow cylindrical segment.

This in each case results in a first tongue 37a and a second tongue 37b which each form a side wall of the thread 31a and 31b concerned and which are each unilaterally connected in the area of the end of the thread only. In particular, if the fastening element is made of a plastic and the tongues 37a and 37b are dimensioned not to be too wide, they behave like leaf spring elements as a result. i.e. the tongues 37a and 37b can be elastically bent outward slightly in a radial direction without excessive force. Preferably, this effect is used to decisively facilitate locking in place of the catching recesses 35 installed in the tongues into the complementary edges 36—as soon as the tips of the tongues 37a and 37b contact the catching edges 36 in the context of closing the container, they radially move out of the way in a radial direction and preferably only fully spring back radially into their original position once the catching edges 36 have looked in place in the catching recesses 35. As is best seen in FIG. 13, the free screw areas 33a and 33b each essentially extend across one half of the circumference of the fastening element. Essentially, the same, of course, also applies to the free screw areas 34a and 34b on the side of the counterpart, in this case of the applicator.

The design of cap 3 of the applicator is also remarkable. This cap is particularly preferred to be produced so that it does not enclose a cavity in the direction of the circumference.

To this end, the cap is created from a number of solid lamellas 27 which are each separated from each other by a free space 28.

The lamellas 27 can be arranged in such a way that they radially diverge from a joint centre in an essentially radial direction. This is the solution which FIGS. 9 to 12 and 14 illustrate.

On the side facing the bristles the lamellas end in a solid, preferably essentially circular cylindrical plate 30. Ideally, the fastening as per the invention or the said short thread is formed on the circumference of this plate 30.

An alternative design of this is illustrated in FIG. 15. The cap 3 shown in this figure consists of a number of lamellas 27 which are essentially aligned in a parallel position to each other and, as a result, are separated from each other by the free spaces 28 which (as regards the circumference of the cap) are open towards the outside on two diametrically opposite points of the circumference of the cap. Preferably, the individual lamellas 27 are connected with each other in the area of the centre of the cap via a cross web which is preferably vertical to the main direction. FIG. 15 shows a section at a level which is vertical to the longitudinal axis L of the applicator or of the cap after the plate 30. Of course, in such an arrangement of the lamellas 27, the cap can also taper towards the end facing away from the bristle brush. For example, it can taper in such a way with an almond shape with a preferably convex surface enveloping the circumference as is shown in FIG. 9.

As is shown above, procedural protection is requested for the invention in due course, in particular, in the form of the following claims:

Procedure for the production of a cosmetics applicator (1) according to one of the claims in which in a first step of the procedure a workpiece which consists of a cap (3) forming a grip area (2) on its outer circumference for tight sealing of the cosmetics reservoir, which moves into a shaft (4) protruding from it in one piece which shaft forms a handle segment (5) and a bristle-carrying segment (6) is produced preferably by using an injection moulding procedure and in which in a second step of production the bristles (7) are injected on the bristle-carrying segment (6) either in such a way that the bristle-forming plastic compound is injected into the hollow interior (9) of the bristle-carrying segment (6) during which process, on the one hand, the injection pressure has to be selected to be at a level which is high enough to ensure that the bristle-forming plastic compound locally penetrates the wall of the bristle-carrying segment (6) in a radial outward direction wherever the wall is hollow because it bridges a bristle-forming cavity which is initially unfilled and, on the other hand, the pressure needs to be low enough to ensure that the bristle-forming plastic compound does not penetrate into the still warm solid separating segment (10) of the shaft (4) which prevents the ingress of the bristle-forming plastic compound in the direction of the cap (3) or that the bristle-carrying segment 6 is surrounded by a sleeve 24 from which the bristles protrude and is welded with it.

Procedure according to the specification in the paragraph above characterised by the fact that the bristle-carrying segment (6) is shaped from the mould reflecting it after injection moulding of the workpiece, while the remaining workpiece stays in the mould cavity of the main mould used to produce it and is then inserted into a second mould which fully encloses its external circumference and which has the bristle-forming cavities (20) and is positioned so that it sits closely on the shaft (4).

Procedure according to the claims, the specifications in the two paragraphs herein above in which the main mould is turned from the mould reflecting it after shaping of the bristle-carrying segment (6) and in which the bristle-carrying segment (6) is only inserted into the mould reflecting the shape of the bristles at this point.

Procedure according to the specifications in one of the three paragraphs above in which the joint between the main mould and the mould reflecting the bristle-carrying segment is located at one level which transects the solid separating segment (10) of the shaft (4).

Claims

1. A mascara applicator, comprising:

a cap forming a grip area for tight sealing of a cosmetics reservoir, which turns into a shaft protruding from the cap as one piece which, in turn, in one piece forms a handle segment and a bristle-carrying segment, with the bristle-carrying segment having a hollow interior structure and carrying injected bristles which are integrally connected through a wall of the bristle-carrying segment with a plastic core covering or filling an inside of the bristle-carrying segment, wherein the cap and the shaft consist of a different plastic material than the plastic core and the bristles.

2. The mascara applicator according to claim 1, wherein a cavity of the bristle-carrying segment is open towards an outside on a face side of the bristle-carrying segment facing away from the cap.

3. The mascara applicator according to claim 1, wherein the bristle-carrying segment has an essentially constant wall thickness of ≦0.3 mm and and the handle has a wall thickness of ≦2.25 mm in its hollow segment.

4. The mascara applicator according to claim 2, wherein the handle segment is at least partly hollow and has a separating segment which closely separates its cavity from the cavity of the bristle-carrying segment.

5. The mascara applicator according to claim 1, wherein the handle segment is solid on its end facing the bristle-carrying segment along a separating segment which accounts for approximately ⅕ to ½ of its total length.

6. The mascara applicator according to claim 1, wherein a wall thickness of the bristle-carrying segment increases immediately before a transition from the bristle-carrying segment to the handle segment, in such a way that a wall thickness of the bristle-carrying segment increases towards the inside.

7. The mascara applicator according to claim 1, wherein the shaft is consistently hollow on an inside and forms a duct via which a plastic compound which is injected for the purpose of manufacturing the bristles can flow into an area of the cap, up to an area of an outer circumference of the cap.

8. The mascara applicator according to claim 1, wherein an outer diameter (OH) of the handle segment or of a sleeve surrounding the handle segment is essentially or consistently bigger than an outer diameter (OB) of the bristle-carrying segment with the OH/OB ratio being ≦0.8.

9. The mascara applicator according to claim 1, wherein the cap is executed without a thread and designed in such a way that the cap is fastened for a tight seat of the mascara applicator on the cosmetics reservoir and/or that the cap can positively lock in place on the cosmetics reservoir.

10. The mascara applicator according to claim 1, wherein on the cap a fastening element on a cap side is provided for which is decided as an external thread.

11. The mascara applicator according to claim 1, wherein a fastening element is provided on the cap to form an applicator quick release fastener together with a corresponding fastening element on the reservoir side, and the applicator quick release fastener is designed as a bayonet coupling or as a multi-start short thread and dimensioned so that the fastening element on the cap side and on the reservoir side can be transferred from a fully closed position to a position in which these parts are no longer fastened in a direction of a longitudinal axis of the applicator by a rotation of ≦⅜ of a turn.

12. The mascara applicator according to claim 11, wherein the short thread is a steep thread with a gradient μ of more than 5°.

13. The mascara applicator according to claim 11, further comprising an additional holder that holds the fastening element on the cap side and the fastening element interacting with it on the container side together, in addition to the existing sliding friction, as soon as the fastening elements have reached their fully closed position with the additional holder being a catching edge which if travelled over makes a tongue connected on one side on the fastening element on the container spring out radially in order to slide into a catching recess in an area of the tongue afterwards.

14. The mascara applicator according to claim 1, wherein a major part of the cap is formed by ribs protruding radially from a joint centre all around or by a number of ribs which are essentially positioned next to each other in parallel.

15. The mascara applicator according to claim 14, wherein, on its end facing the bristles, the cap ends in a solid plate which as one piece moves into the shaft on one face side, while the cap moves into the ribs on its other face side.

16. The mascara applicator according to claim 1, wherein, on a side facing away from the bristles, the handle segment turns into a plate which essentially extends in a radial direction as one piece, which plate, in turn, turns into the cap as one piece.

17. The mascara applicator according to claim 1, wherein the cap has a shape of a tube open on both face sides which forms an operating area directly accessible for a final consumer on its external circumference with the tube having an essentially constant wall thickness.

18. The mascara applicator according to claim 16, wherein the plate has an opening connecting a cavity of the handle segment with a subsequent cavity surrounded by the cap in a direction of a circumference.

19. The mascara applicator according to claim 16, wherein the plate follows the segment of the handle segment which has a bigger outside diameter as against the rest of the handle segment which is dimensioned so that the plate lies flat against an inner circumference of a scraper if the applicator is fully inserted into the reservoir.

20. A cosmetics unit consisting of a cosmetics reservoir and the mascara applicator according to claim 1, wherein the cosmetics reservoir comprises a fastening element with a thread worked into a hollow cylindrical segment of the fastening element in such a manner that the two threads fully penetrate the wall of the hollow cylindrical segment in a radial direction, thereby each forming a “window” in the wall of the hollow cylindrical segment.