The invention concerns a dispenser stick for storing and applying a pasty dispensable stick compound that consists of a cosmetic product or some other type of product, for example, a deodorant stick or glue stick, which comprises a stick-shaped housing with an upper dispensing outlet, a closure cap that seals the dispensing outlet airtight by means of a sealing lip, and a feeding plunger that can be moved axially inside the housing.
Dispenser sticks for applying a pasty dispensable product, for example, deodorant sticks or glue sticks, are known in various designs. Dispenser sticks in which the stick compound is used by moving it upward out of the dispensing outlet by a supporting plunger by means of a rotating base with a spindle or by a pushing device are widely used. To use this type of dispenser stick, the closure cap must first be removed and then the plunger must be pushed up. Accordingly, two separate manual operations are necessary to place the dispenser stick in a position for applying it.
To create a dispenser stick that has a simpler design and is easier to use, German Utility Patent GM 76 13 989 proposes that the closure cap be sealed against the housing by means of a sealing lip in such a way that, when the closure cap is removed, the stick compound is pushed a certain distance out of the housing by the negative pressure produced by the removal of the cap. A rotating spindle or a pushing device is no longer necessary. The only function of the plunger as a feeding plunger is to provide an airtight seal of the stick compound towards the bottom.
A disadvantage of this previously known dispenser stick is that the stick compound is pushed back into the housing during its application. The only resistance to the stick compound being pushed back into the housing is the static friction of the feeding plunger and, depending on that, the static friction of the stick compound on the inside wall of the housing as well. This static friction may not be too great, either, because it must be possible, even if the stick compound that has been pushed out is not used, to screw the closure cap back onto the housing, at which time the protruding stick compound is pushed back into the housing. In this regard, when the stick compound is pushed back into the housing, it is unavoidable that the stick compound is forced out to the side at the upper edge of the housing.
Proceeding from this prior art, the objective of the invention is to design a dispenser stick of the specified type in such a way that, despite continued simple design and handling, the disadvantage of the stick compound being pushed back into the housing is eliminated.
This objective is achieved with the characterizing features of claim 1, according to which the feeding plunger can be moved only towards the dispensing outlet and is locked in the opposite direction, and the closure cap is designed with a double wall with an inner cap that can be axially displaced relative to the closure cap. Advantageous modifications of the invention are specified in the dependent claims.
The locking of the feeding plunger in the direction opposite the dispensing direction in accordance with the invention advantageously prevents the stick compound from being pushed back into the housing as the stick compound is being applied, during which axial pressure on the stick compound is unavoidable. This locking of the feeding plunger is accomplished, for example, by mounting a retaining spring below the feeding plunger. The retaining spring catches on the inside wall of the housing and is designed in such a way that axial displacement in the dispensing direction remains possible.
Alternatively, in accordance with an advantageous modification of the invention, the inside wall of the housing can be provided with fine serration or with fine locking grooves, in which the correspondingly designed feeding plunger catches to lock it in the direction opposite the dispensing direction.
Since the stick compound that has been pushed out of the housing for application can no longer be pushed back into the housing, but it must be possible to close the dispenser stick even with unused stick compound that has been pushed out, in accordance with the invention, the closure cap is designed with a double wall and an inner cap. As the closure cap is being screwed onto the housing, the inner cap sets down on the protruding stick compound and is then pushed axially into the closure cap as the screwing operation continues. The inner cap is connected with the closure cap by a spring element in such a way that it is supported, so that when the cap is unscrewed again, initially only the closure cap and then the inner cap are axially displaced due to the spring tension that was previously produced.
In an advantageous modification of the invention, both the closure cap and the housing have a double-walled construction. An axially displaceable inner housing, which extends from the top of the outer housing and serves to hold the stick compound, is mounted inside the outer housing, which can be closed with the closure cap. The length of the part of the inner housing that extends from the outer housing corresponds to the length of the inner cap, so that when the closure cap is screwed on, the upper base of the inner cap rests on the upper edge of the inner housing, and the lower edge of the inner cap rests on the upper edge of the outer housing.
A crucial advantage of this double-walled design of the housing is seen during the filling of the inner housing with the stick compound, which is usually still liquid at this point. The inner housing, which is pushed only partially into the outer housing during the filling operation, is pushed completely into the outer housing after the filling operation has been completed and the stick compound has hardened, and the stick compound and the feeding plunger, which rests on a central projection of the base of the housing, remain unchanged in their position. This causes the stick compound to be pushed within the inner housing towards the dispensing outlet, so that the stick compound becomes detached from the inner wall of the inner housing. The usual adhesion of the stick compound to the inner wall of the housing that occurs during the filling operation in previously known dispenser sticks is thus successfully prevented before the first use despite the conventional filling operation, and the stick compound can then be easily advanced even during its first use.
The advancing of the stick compound in the dispenser stick of the invention to allow it to be applied occurs indirectly by the production of a negative pressure between the inner cap and the inner housing when the closure cap is screwed on. For this purpose, the upper projecting region of the inner housing is provided with an outwardly projecting annular sealing lip, which, when the closure cap has been screwed on, rests against the inner wall of the inner cap and produces a seal. In this regard, a cavity formed between the inner housing and the inner cap is sealed towards the bottom by the sealing lip. When the closure cap is unscrewed and the inner cap is moved axially upward in the dispensing direction, this cavity becomes larger, and the resulting negative pressure “pulls” the column of stick compound a small distance upward out of the dispensing outlet. The possible amount of this axial displacement of the stick compound is adjusted in advance by suitable shaping of the annular cavity between the inner cap and the inner housing.
In accordance with the invention, the sealing lip is mounted at a downward angle on the inner housing in such a way that it acts as a check valve, and when the outer housing is closed by the closure cap, the resulting positive air pressure inside the diminishing annular cavity is relieved to the outside by venting via the sealing lip.
Further advantages, features, and properties of the invention, especially the manner of operation of the dispenser stick of the invention, are explained in greater detail below with reference to the specific embodiments illustrated in the drawings.
a shows details of
a to 3c show vertical sections of the dispenser stick of
a and 4b show two different enlarged partial sections of
FIGS. 5 to 9 show vertical sections of the dispenser stick of
FIGS. 11 to 13 show the housing of the dispenser stick of
The exploded view in
The housing 1′ of the dispenser stick consists of an outer housing 9, which is closed at the bottom and into which the longer inner housing 6 can be inserted from above. The inner housing 6 has a tubular construction, so that the feeding plunger 7 with the retaining spring mounted below it can be inserted through the open lower end. The upper region of the inner housing 6 that projects above the outer housing 9 is formed with two annular webs 15, between which the downwardly angled sealing lip 5 is mounted. Below the annular webs 15, the lower end of the inner housing 6 is provided with additional annular webs 16a, 16b, 16c, which support the inserted inner housing 6 against the outer housing 9. The upper part of the outer housing 9 is provided with an external thread 11, onto which the closure cap 2 with the inserted helical spring 4 and inner cap 3 is screwed to close the dispenser stick 1.
a to 3c each show front elevations of the dispenser stick 1 and the housing 1′ in different positions of use.
In
In
As
In the dispenser stick 1 of FIGS. 1 to 9, the locking effect on the feeding plunger 7 was produced by a retaining spring 8 mounted below the feeding plunger 7. In accordance with the invention, however, this locking effect can also be produced solely by a feeding plunger 7 with an inner housing suitably adapted to achieve this effect. In
In accordance with the invention, the housing 1′ of the dispenser stick 1 can have a double-walled design. The principle on which this housing design is based for simple filling with stick compound 10 will now be explained in greater detail with reference to FIGS. 11 to 13.
To ensure that the inner housing 6 can be inserted into the outer housing 9 as far as the housing base 17 after the filling operation has been completed, while the position of the feeding plunger 7 remains unchanged, in the embodiment shown in Figures 11 to 13, the feeding plunger 7 rests in the filled position on a central projection 23 of the housing base 17 some distance above the housing base 17. Alternatively, however, it is also possible, in accordance with the invention, as is shown in the vertical partial section of
The invention is not limited to the illustrated embodiments but rather can be constructed in a variety of ways with respect to the design and the individual required components of the dispenser stick as long as the features of the invention of a double-walled design of the closure cap and a design of the feeding plunger with a reverse movement arresting mechanism are retained.
Number | Date | Country | Kind |
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203 13 223.8 | Aug 2003 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP04/09388 | 8/23/2004 | WO | 10/13/2005 |