Patent Description:
Tampon applicators of this kind are known in the art. In these applicators, the enlarged ends of the plungers not only provide an enlarged contact area for the tampon and the finger, respectively, but they also prevent that the plunger may fall out of the barrel. Up to now, two methods for introducing the plunger into the barrel have become known. According to patent <CIT>, the plunger is first manufactured as a hollow cylinder and introduced into the guide section of the barrel, and the ends of the plunger are then widened by means of a heated tool. According to patent application <CIT>, the guide section is formed by a plurality of ridges extending radially inwards in the plunger end of the barrel, and an enlarged end of the plunger is pushed into the guide section such that the enlarged portion is deformed during the movement through the guide section and restored after leaving the guide section.

It is obvious that the method according to <CIT> is relatively laborious as the initially cylindrical plunger has to be introduced into the barrel and then widened on both sides. The method according to <CIT> is only applicable with hollow, relatively thin-walled plungers since one of the enlarged ends of the plunger has to be deformable by the radial ridges in the guide section. Plungers that are not hollow and relatively thick-walled plungers, as well as plungers where the end that is to be pushed through the guide section has an increased wall thickness, cannot be mounted with this method. An increase in wall thickness may e.g. be the result of the thermal deformation of a cylindrical plunger end or of the manufacture of the plunger by injection molding.

The documents <CIT>, <CIT> and <CIT> show similar tampon applicators with guided plungers.

On the background of this prior art it is the object of the invention to suggest a tampon applicator in which the plunger is easy to mount even if it is thick-walled or at least has an end having an increased wall thickness.

According to the invention, this object is achieved in that the guide section is formed by a number of radially resilient elastic fins as defined by claim <NUM>.

In particular, this solution according to the invention offers the advantage that the elastic fins yield elastically while the plunger is being mounted and therefore no specific requirements apply to the plunger as to its elasticity. Moreover, since the elastic fins are radially resilient, they may be dimensioned so as to lie against the portion between the ends of the mounted plunger without play and thus optimally guide the plunger. Furthermore, the elastic fins are able to guide the plunger on a large part of its circumference, which is not possible with the ridges according to <CIT>.

The terms "internal diameter" and "external diameter" as used in the present context are not meant to limit the invention to barrels and plungers of circular cross-section but shall also include other cross-sectional shapes such as oval or polygonal ones.

According to one embodiment of the invention, the barrel has a receiving section for the tampon and a gripping section arranged in the area of its plunger end and whose external diameter is smaller than the external diameter of the receiving section. This allows a better handling of the tampon applicator.

According to a further embodiment, the plunger is hollow and the first end and/or the second end of the plunger has a greater wall thickness than the portion of the plunger between its ends. This configuration simplifies the manufacture of the plunger in that the plunger may e.g. be produced by injection-molding.

According to the invention, the elastic fins extend from the inner circumference of the barrel in the longitudinal direction of the barrel and are inclined toward the longitudinal axis of the barrel. This inclination simplifies the insertion of the preceding plunger end while the plunger is being mounted.

According to the invention, the elastic fins have respective first sections extending, as seen in cross-section, from the inner circumference of the barrel in the direction of a chord, followed by second sections extending substantially parallelly to the inner circumference of the barrel. The area in which the elastic fins are connected to the wall of the barrel extends in the longitudinal direction of the barrel substantially.

According to a further embodiment, the elastic fins are bent more than <NUM> degrees between their first sections and their second sections. The bent sections act like cantilever springs, and allow a shorter design of the elastic fins in the circumferential direction, which in turn allows arranging a greater number of elastic fins.

According to a further embodiment, the second sections of the elastic fins extend on both sides of their first sections in the circumferential direction. This allows a nearly gapless conformation of the guide section.

Another aspect of the invention relates to the assembly of the tampon applicator of the invention, as defined by claim <NUM>, which should also be possible with a relatively rigid plunger, in the extreme case even with a plunger that is not hollow. Accordingly, it is suggested that the plunger is mounted by being pushed through the guide section from one end of the barrel, that the preceding plunger end forces the elastic fins outwards in a substantially radial direction so that the diameter of the guide section is temporarily enlarged, and that after the passage of the preceding end through the guide section, the elastic fins return to their positions prior to the passage of the preceding plunger end.

Exemplary embodiments of the invention are shown in <FIG>, and will be described in more detail hereinafter with reference to the appended drawings showing.

<FIG> show a tampon applicator <NUM>, not according to the invention, <FIG> showing an overview of a tampon applicator assembly <NUM> in a longitudinal section. Assembly <NUM> consists of a barrel <NUM> having a longitudinal axis <NUM>, a tampon <NUM> received in a receiving section <NUM> of barrel <NUM> and having a withdrawal string <NUM>, and a plunger <NUM> for ejecting tampon <NUM> from barrel <NUM>. Barrel <NUM> and plunger <NUM> form the tampon applicator. In the illustration of <FIG>, the insertion end <NUM> of assembly <NUM> is closed by a number of lips <NUM> (see <FIG>) that are integrally formed on barrel <NUM> and are bent inwards. In <FIG>, which shows barrel <NUM> alone in a perspective view, lips <NUM> are illustrated in the open position. At its plunger end <NUM>, barrel <NUM> has a gripping section <NUM> having a reduced diameter relative to receiving section <NUM>. This diameter reduction is not compulsory; gripping section <NUM> might alternatively have the same external diameter as receiving section <NUM>. At its ends, plunger <NUM> has a tampon side enlargement <NUM> and a finger enlargement <NUM>.

<FIG> shows a detail of <FIG>, however without tampon <NUM> and withdrawal string <NUM> and on an enlarged scale relative to <FIG>. On the inner circumference of gripping section <NUM>, elastic fins <NUM> are arranged that are connected by their foot sections <NUM> to the wall of barrel <NUM> and whose free ends are oriented inwards and in the direction of the plunger end of barrel <NUM>. The contact surfaces <NUM> of elastic fins <NUM> on plunger <NUM> form a guide section <NUM> for plunger <NUM>. In the depicted example, four elastic fins <NUM> are arranged on the inner circumference of gripping section <NUM>, while it is seen in <FIG> that between two respective elastic fins <NUM> a gap <NUM> is provided such that the free ends of elastic fins <NUM> may elastically move outwards and inwards radially. In receiving section <NUM> of barrel <NUM>, inwardly or outwardly projecting ridges <NUM> may be provided for increased stiffness, and in gripping section <NUM>, a gripping structure <NUM> may be arranged to prevent slipping of the fingers during the insertion of assembly <NUM>. <FIG> shows a detail of plunger <NUM> with finger enlargement <NUM> and clearly illustrates that this area may have an increased wall thickness since this portion - as opposed to the prior art known from reference <CIT> - is not subject to a deformation during the assembly of the plunger.

To mount plunger <NUM> in barrel <NUM>, plunger <NUM> is introduced into insertion end <NUM> of barrel <NUM> with finger enlargement <NUM> first. During the passage of finger enlargement <NUM> through gripping section <NUM>, the free ends of elastic fins <NUM> are forced radially outwards by finger enlargement <NUM>, resiliently return after the passage of finger enlargement <NUM>, and then lie against the outer circumference of middle section of plunger <NUM>.

Alternatively, which is not illustrated in the drawings, the free ends of elastic fins <NUM> may be directed against insertion end <NUM> of barrel <NUM>. In this case, the plunger is mounted from plunger end <NUM> of barrel <NUM>, plunger <NUM> being introduced into the interior of gripping section <NUM> with tampon side enlargement <NUM> first.

<FIG> show embodiments of a barrel <NUM> of tampon applicator <NUM> according to the invention as seen from plunger end <NUM>. In the embodiment according to <FIG>, elastic fins <NUM>' are composed of respective straight sections <NUM> extending from the wall of barrel <NUM> in the direction of a chord and of adjoining curved contact sections <NUM> for the plunger. The indication "direction of a chord" means that the corresponding area is not directed towards the cross-sectional center of barrel <NUM> but approximately tangential to plunger <NUM> received in guide section <NUM>. In this manner, elastic fins <NUM>', <NUM>'', and <NUM>‴ are capable of resiliently yielding radially outwards during the passage of finger enlargement <NUM> while the plunger is being mounted. In the embodiment according to <FIG>, elastic fins <NUM>" also have straight sections <NUM> which also project from the wall of barrel <NUM> in the direction of a chord but are shorter than the straight sections <NUM> in the exemplary embodiment according to <FIG>. These straight sections <NUM> are followed by arcs <NUM> that are in turn followed by contact sections <NUM> for the plunger. Due to this configuration, elastic fins <NUM>'' require less space in the circumferential direction than elastic fins <NUM>' according to the previously described example. In this manner, e.g. five or six elastic fins <NUM>'' can be arranged on the inner circumference of the gripping section. In the exemplary embodiment according to <FIG> also, straight sections <NUM> extending from the wall of barrel <NUM> in the direction of a chord are again provided. At their ends, they carry contact sections <NUM> which project on both sides from the straight sections <NUM> in the circumferential direction and thus ensure a particularly effective guidance of plunger <NUM>.

In the exemplary embodiments of <FIG>, elastic fins <NUM>', <NUM>'', and <NUM>‴ are arranged such that their sections that are to be contacted by one end of plunger <NUM> while plunger <NUM> is being mounted have a larger clear diameter at the location where they are first contacted during the insertion of plunger <NUM>. In the illustrated examples, the clear diameter defined by contact sections <NUM>, <NUM>, and <NUM> conically decreases towards the plunger end <NUM> of barrel <NUM>. Accordingly, in these exemplary embodiments, the plunger is mounted from the insertion end <NUM> of barrel <NUM> with finger enlargement <NUM> first. In alternative examples that are not illustrated in the drawings, the inclination of the aforementioned sections might be inverse so that plunger <NUM> could be mounted from the plunger end <NUM> of barrel <NUM> with tampon side enlargement <NUM> first.

In the exemplary embodiments of <FIG>, contact sections <NUM>, <NUM>, and <NUM> are not only connected to the wall of barrel <NUM> by straight sections <NUM>, <NUM>, and <NUM>, but additionally on their sides facing away from the viewer, similarly to the foot sections <NUM> in the embodiment according to <FIG>. This is not compulsory, however, but each contact section <NUM>, <NUM>, and <NUM> may have two free ends in the longitudinal direction of barrel <NUM>, namely as illustrated in the area of plunger end <NUM> and as opposed to the illustrations on their sides facing away from plunger end <NUM>.

In all illustrated and previously described exemplary embodiments, four elastic fins <NUM>', <NUM>'', or <NUM>‴ are distributed on the inner circumference of gripping section <NUM>. However, the invention is not limited to four elastic fins but two, three, five, six, or more elastic fins may be provided.

In all illustrated and previously described exemplary embodiments, barrel <NUM> is preferably made of a preferentially thermoplastic material and is preferably produced by the injection molding technique. Elastic fins <NUM>', <NUM>", or <NUM>‴ are preferably formed integrally with barrel <NUM>. Alternatively, however, elastic fins <NUM>', <NUM>'', or <NUM>‴ may e.g. be formed on a ring (not shown) that is connected to the barrel, e.g. by a snap connection. In this manner, the range of possible designs of the elastic fins is extended with regard to tool techniques in that elastic fins may be manufactured that would be difficult or impossible to realize integrally with the barrel.

Ultimately, as a matter of form, it should be noted that for a better understanding of the structure of the tampon applicator assembly, the latter or its components, respectively, are partly illustrated out of scale and/or on an enlarged or reduced scale.

Claim 1:
Tampon applicator (<NUM>) comprising a barrel (<NUM>) for receiving a tampon (<NUM>) and a plunger (<NUM>) for ejecting the tampon (<NUM>) from the barrel (<NUM>), the barrel (<NUM>) having an insertion end (<NUM>) and a plunger end (<NUM>) and in the area of its plunger end a guide section (<NUM>) for the plunger (<NUM>), the plunger (<NUM>) having a first enlarged end (<NUM>) for contact with the tampon (<NUM>) and a second enlarged end (<NUM>) for contact with a finger, and the internal diameter of the guide section (<NUM>) of the barrel (<NUM>) being smaller than the external diameter of the first and second ends (<NUM>, <NUM>) of the plunger (<NUM>), the guide section (<NUM>) being formed by a number of radially resilient elastic fins ( <NUM>'; <NUM>"; <NUM>‴) that are distributed on the inner circumference of the barrel (<NUM>), wherein the elastic fins (<NUM>) extend from the inner circumference of the barrel (<NUM>) in the longitudinal direction of the barrel and are inclined toward the longitudinal axis (<NUM>) of the barrel (<NUM>), and characterized in that the elastic fins (<NUM>'; <NUM>"; <NUM>‴) have respective first sections (<NUM>; <NUM>; <NUM>) extending, as seen in cross-section, from the inner circumference of the barrel (<NUM>) in the direction of a chord, followed by second sections (<NUM>; <NUM>; <NUM>) extending substantially parallelly to the inner circumference of the barrel (<NUM>).