EP0553441A1 - Device for applying a liquid - Google Patents

Abstract

A device for applying liquids, for example a writing device, has a housing in which a reservoir (13) for the liquid is formed. Arranged in an opening of the housing is a bundle of bristles (12, 17) with which liquid from the reservoir can be applied to a surface. In order to be able to supply the bundle of bristles (12, 17) with a suitable amount of a liquid in a constructionally simple manner, a wick body (13) is arranged in the housing directly upstream of the bundle of bristles. The wick body (13) transfers the liquid to the bundle of bristles, the latter being at least partially inserted in the wick body (13). <IMAGE>

Description

The invention relates to a device for applying liquids, in particular a writing device, with a housing in which a storage for the liquid is formed and at least one bristle bundle arranged in an opening of the housing, by means of which the liquid flowing to it can be applied.

Liquid applicators are known as writing implements, so-called felt or fiber pens, in which the writing tip consists of a cut felt strip, of resinized and shaped or shaped fiber bundles or of extruded capillary profiles. The writing tip is fed from a memory with writing fluid which is transferred to a writing surface, for example a sheet of paper can. When liquid is dispensed from the writing tip, liquid is replenished from the memory due to capillary forces.

However, such a felt-tip or fiber-tip pen has the disadvantage that the liquid in the writing tip dries up relatively easily if the pen is left open for a long time and is not used. In this case it is very difficult to reactivate the writing tip and to achieve an even dispensing of liquid.

In many applications it is desirable to be able to vary the line width. However, since the tip of known felt or fiber pens is essentially non-deformable in use, the line width is determined solely by the shape of the tip. An individual adjustment of the line width is not possible in this way. The line thickness also changes in many cases with increasing service life due to signs of wear on the application material.

From GB 12 44 015, from which the preamble of claim 1 is based, a liquid applicator is known in which the writing tip consists of a bundle of bristles, the rear, inner end of which is immersed in a liquid located in a reservoir. By the front, free end of the bristle bundle over a base, for. B. a sheet of paper is guided, liquid is released from the bristle bundle to the paper, with liquid flowing from the memory into the bristle bundle due to the capillary action. Dependent on the contact pressure of the bristles on the base and thus the line thickness can be varied by the pressure with which the writing tip is pressed onto the base, and the amount of the liquid dispensed can also be changed by the user.

If the liquid in the bristle bundle should dry out, the writing tip can be reactivated in a simple manner by flexing movements of the bristles.

However, it has been shown that such a liquid applicator leads to an undesirable leakage of liquid, since the bristles are immersed directly in the liquid in the reservoir and a defined capillarity in the bundle of bristles cannot be guaranteed due to manufacturing tolerances. In order to avoid the escape of liquid, according to DE 35 25 150 A1, DE 37 00 413 A1 and DE 37 11 236 A1, metering devices in the form of a valve to be operated by the user are arranged between the reservoir and the bristle bundle. By means of the valve, the amount of liquid supplied to the bristle bundle can be metered in the desired manner, but due to their structurally complex construction, these liquid applicators are very function-sensitive and expensive.

The invention has for its object to provide a device of the type mentioned, in which the suitable amount of liquid can be supplied to the bundle of bristles in a structurally simple and functionally reliable manner.

This object is achieved in that a wick body is provided in the housing, which is arranged upstream of the bristle bundle in the direction of flow and dispenses the liquid to the bristle bundle, and that the bristle bundle is at least partially inserted into the wick body.

The wick body ensures a uniform supply of the bristle bundle with a small but sufficient amount of liquid. When liquid is released from the bristle bundle during use, the liquid is sucked into the bristle bundle by capillary forces from the wick body. As a result, capillary forces are also effective in the wick body, which bring about a replenishment of liquid in the wick body. The wick body thus acts on the one hand as an automatically operating metering device, by means of which the appropriate amount of liquid is always supplied to the bristle bundle, and on the other hand as a buffer that prevents direct access of the liquid to the bristle bundle. The outflow of the liquid during the application process is not only determined by the bundle of bristles and its capillarity, but is also significantly influenced by the body of the wick and its hydraulic properties.

The design effort is low, in particular the arrangement of spring-loaded valve bodies and the formation of corresponding valve seats with necessarily narrow manufacturing tolerances as in the known liquid applicators is not necessary. In the device according to the invention, neither particularly complex manufacturing techniques are necessary, nor can malfunctions enter. The device can be manufactured in a simple and inexpensive manner.

According to the invention, the at least one bundle of bristles is held directly in the wick body. In this way, on the one hand, the formation of a separate holder is avoided, as a result of which the construction is simple, and on the other hand, the bundle of bristles can be reliably held in contact with the wick body, so that it is ensured that the capillary suction forces which occur in the bristle bundle as a result of liquid being released occur the wick body are transferred. This ensures that the liquid flows from the wick body into the bundle of bristles in the desired manner.

If it is provided in a preferred embodiment of the invention that the wick body is arranged between the reservoir and the bristle bundle, it can be ensured in a structurally simple manner that the liquid from the reservoir must flow through the wick body. This series connection of memory, wick body and bristle bundle in terms of flow technology reliably prevents the bristle bundle from being fed with liquid directly from the reservoir, which could entail the disadvantages described.

In order to ensure a steady, slow flow of the liquid in the wick body due to the capillary forces, it makes sense that the wick body does not take up excessive liquid from the reservoir and that the liquid in the wick body has a sufficient length Has flow path. This can be achieved in a simple manner in that the wick body is connected to the memory at its inner end. The liquid entering the wick body from the reservoir must therefore flow through the wick body over a relatively long distance, as a result of which the flow is evened out.

Alternatively or additionally, it can be provided that the wick body forms the storage. If necessary, the separate formation of a liquid reservoir can thus be dispensed with, as a result of which the device can be manufactured inexpensively. In this case, the wick body can completely fill the interior of the housing, so that a sufficient amount of liquid can be stored in the wick body.

In order to reliably ensure that no impurities which could influence the liquid discharge can occur on the end face of the bristle bundle, it is provided that the bristle bundle is arranged at a distance from the inner end of the wick body.

The bundle of bristles is preferably held in a blind hole in the wick body. The arrangement of the bristle bundle in the blind hole represents a structurally particularly simple configuration and also ensures precise positioning and secure holding of the bristle bundle with a corresponding blind hole depth. Furthermore, the bristle bundle is in contact with the wick body over a relatively large area, which prevents the liquid from flowing in evenly the wick body into the bristle bundle is possible both via its inner end face and from the side, ie over the usually cylindrical contact surface. For handling reasons, it is advantageous if, when only one bundle of bristles is arranged, the corresponding blind hole is formed in the central axis of the wick body.

The bundle of bristles can be held in the blind hole in various ways. It has proven to be particularly advantageous if the bristle bundle is held in the blind hole by means of a press fit. In this way, the arrangement of special fasteners can be dispensed with. Additionally or alternatively, it can be provided that the bristle bundle is held in a form-fitting manner in the blind hole of the wick body. Fastening the bundle of bristles in the blind hole due to its shape ensures that the bundle of bristles cannot unintentionally come loose. It has proven useful if an annular flange is formed at the inner end of the bristle bundle by melting the bristle ends, by means of which the bristle bundle is bumped into the blind hole.

In a preferred development of the invention it is provided that the housing holds the wick body under a radially inward bias. In this way, the wick body tightens against the bundle of bristles inserted into the blind hole, as a result of which the frictional forces between the wick body and the bundle of bristles are significantly increased. In addition, the entire outer surface of the bristle bundle is used to hold it, so that external loads on the bristle bundle that occur during use over the entire surface can be derived.

Instead of a single bristle bundle, several bristle bundles can also be provided. Here, several, preferably four blind holes are formed, in each of which a bundle of bristles is held, arranged uniformly over the cross section of the wick body. The individual bristle bundles can assume the position of the corners of a square in cross section, for example.

In an advantageous embodiment of the invention it is provided that the bristle bundle extends to the inner end of the wick body, the liquid penetrating from the wick body into the bristle bundle via the outer surface of the bundle. If the bristle bundle completely penetrates or is surrounded by the wick body, the bristle bundle and the wick body can be produced continuously in a single operation, for example by foaming a bristle strand or bringing it together with a fiber bundle strand. After cutting to length and mechanical processing of a working or writing tip, a bristle bundle wick body unit can be created in a simple and quick manner, which only has to be inserted into a housing.

In order to prevent the direct inflow of liquid from the reservoir into the bristle bundle via its end face, in order to avoid the above-mentioned problem of undesired outflow of liquid, it can be provided according to the invention that the inner end face of the bristle bundle is closed by gluing, welding, etc. is. Thus the liquid is forced to flow first through the wick body, before it enters the bristle bundle through the outer surface of the bundle of bristles, so that the liquid flow is evened out.

In order to be able to form a tip, for example a writing or brush tip, when arranging a plurality of bristle bundles, the invention provides that the bristle bundles converge towards their free ends. The individual bristle bundles can converge to form a common tip and can thus be arranged inclined to one another in the region of their free end.

If the wick body has a relatively small cross section, the formation of a blind hole can be technically difficult. In this case, the invention provides that the wick body near the opening of the housing has a peripheral peripheral recess and the bundle of bristles is held in the recess between the wick body and the edge of the opening of the housing. The circumferential recess can also be produced in a simple manner with smaller wick bodies. After inserting the bristles or the bundle of bristles into the recess, the housing can be pushed on, whereby the bundle of bristles is clamped between preferably conical sections of the wick body and the housing.

To form a tip, it can be provided that the bristle bundle has a cavity, at least in the area projecting beyond the wick body, and that the bristles converge to a tip on the central axis of the wick body. As already indicated, the body of the wick can consist of fleece, felt or cotton. Instead it is also possible that the wick body consists of an absorbent plastic foam and is foamed onto the bristle bundle or consists of extruded capillary profiles. It has proven to be advantageous if the wick body has fibers oriented essentially in its longitudinal direction.

Figur 1

einen Längsschnitt durch das untere Ende einer Vorrichtung gemäß einem ersten Ausführungsbeispiel,

Figur 2

einen Schnitt II-II gemäß Figur 1,

Figur 3

einen Dochtkörper mit einem Borstenbündel gemäß einem zweiten Ausführungsbeispiel,

Figur 4

einen Längsschnitt durch das untere Ende eines Dochtkörpers gemäß einem dritten Ausführungsbeispiel,

Figur 5

einen Schnitt V-V gemäß Figur 4,

Figur 6

einen Längsschnitt durch das untere Ende eines Dochtkörpers gemäß einem vierten Ausführungsbeispiel,

Figur 7

einen Längsschnitt durch einen Dochtkörper mit einem Borstenbündel gemäß einem fünften Ausführungsbeispiel und

Figur 8a und 8b

eine schematische Darstellung des Flüssigkeitsübertritts von dem Dochtkörper auf das Borstenbündel im Längsschnitt sowie im Querschnitt.

Further details and features of the invention are apparent from the following description of exemplary embodiments with reference to the drawing.
Show it:

Figure 1

2 shows a longitudinal section through the lower end of a device according to a first exemplary embodiment,

Figure 2

2 shows a section II-II according to FIG. 1,

Figure 3

a wick body with a bristle bundle according to a second embodiment,

Figure 4

2 shows a longitudinal section through the lower end of a wick body according to a third exemplary embodiment,

Figure 5

4 shows a section VV according to FIG. 4,

Figure 6

2 shows a longitudinal section through the lower end of a wick body according to a fourth exemplary embodiment,

Figure 7

a longitudinal section through a wick body with a bristle bundle according to a fifth embodiment and

Figures 8a and 8b

is a schematic representation of the liquid transfer from the wick body to the bristle bundle in longitudinal section and in cross section.

The device 10 for applying liquids has an essentially circular-cylindrical housing 11 which is conically tapered in its lower end region shown in FIG. 1 and has an opening 11a at its end. Within the housing 11, a memory for a liquid to be applied, for example ink, is formed in a known manner, not shown, or this memory is formed by the housing. A wick body 13 formed from fleece, felt, wadding or the like is held in the housing 11 below the reservoir, the wick body 13 being fed with liquid from the reservoir. The lower free end of the wick body 13 is located within the housing 11 at a distance from the opening 11a.

The shape of the wick body 13 is adapted to the inner contour of the housing 11, but has a certain excess, so that in its state shown in FIG. 1, in which it is inserted into the housing 11, it is directed radially inwards Prestress is present, and is thus held securely in the housing 11.

A blind hole 14 is formed in the wick body 13. As FIGS. 1 and 2 show, the blind hole 14 runs essentially in the central axis S of the wick body 13 and thus also of the housing 11. A bundle of bristles 12 is inserted into the blind hole 14 and in this, for. B. held by a press fit. The pressing force for holding the bristle bundle 12 is generated in that the cross section of the bristle bundle 12 is larger than the cross section of the blind hole 14 and thus the blind hole 14 is widened when the bristle bundle 12 is inserted. The bristle bundle 12 extends through the opening 11a of the housing 11 and has a z. B. conical application end 12a similar to a writing or brush tip, by means of which the liquid, for. B. ink, paint, nail polish or the like can be applied.

Due to the mobility of the free ends of the bristles of the bristle bundle 12, the contact surface of the bristle bundle 12 on the base or the surface relevant for the liquid discharge and thus the line thickness can be changed depending on the pressure of the bristles.

If liquid, e.g. B. writing fluid, emitted, liquid flows from the capillary forces acting between the bristles Wick body 13 both into the bristle bundle 12 via the inner end face of the bristle bundle 12 and also via its outer surface which is in contact with the wick body 13. The wick body 13 is thereby replenished from the memory, not shown.

FIG. 3 shows an alternative holder for the bristle bundle 12 in the blind hole 14 of the wick body 13. At the inner end of the bristle bundle 12 facing the bottom of the blind hole 14, an annular flange 15 is formed, for example, by melting the bristle ends, so that the bristle bundle can be inserted into the blind hole in a form-fitting manner. The wick body 13 shown in FIG. 3 with the bristle bundle 12 is held in a housing in accordance with FIGS. 1 and 2.

The bristle bundle 12 shown in FIG. 3 has a spherical application end 12a with a relatively large contact surface. This training can be used, for example, in so-called marker pens or for applying cosmetics, for example nail polish.

FIGS. 4 and 5 show an embodiment in which four bundles of bristles 12 are held in the wick body 13. For this purpose, four blind holes 14 are formed in the wick body 13, which are arranged symmetrically to the central axis S of the wick body 13 and have the same angular distance from one another. In the cross section shown in FIG. 5, the blind holes 14 are thus arranged in the corner points of a square. There is a bundle of bristles 12 in each blind hole 14 held in a manner previously described. The bristles of all the bristle bundles 12 run parallel to one another within the wick body 13. At the lower end of the wick body 13, at which the bristle bundles 12 emerge from the respective blind hole 14, the bristles are inclined in the direction of the central axis S of the wick body 13. The bristle bundles 12 converge conically at their free end in a tip P arranged on the central axis S, the bristles also running inclined to one another within each bristle bundle 12.

In the exemplary embodiment shown in FIG. 6, instead of a blind hole at the lower end of the wick body 13, a circumferential recess 16 is formed in its peripheral region, so that the wick body 13 has a stepped cross section. In the recess 16, a sleeve-shaped bristle bundle 17 is inserted, a hollow bristle bundle 17 is inserted, the bristles of which are arranged inclined to one another and converge in a tip P on the central axis S of the wick body 13, so that an essentially point-shaped writing tip is formed. The bristle bundle 17 is held in the recess 16 by means of the conically tapering lower end of the housing 11, which engages around the bristle bundle 17, a clamping force being generated between the housing 11 and the wick body 13.

In the exemplary embodiment according to FIG. 7, a bristle bundle 12 extends over the entire length of the surrounding wick body 13 up to its inner end 13a, a writing tip 12a being formed at the lower end in a known manner. Such a structure can, for example can be achieved by continuously applying a wick body material to a bristle strand and then cutting to length and reworking. The inner end face 12b of the bristle bundle 12 thus lies in one plane with the inner end 13a of the wick body 13.

If the wick body 13 and the bundle of bristles 12 are brought into contact with a liquid in a storage device (not shown), the liquid can only enter the wick body via the inner end face 13a, while a passage of liquid into the bundle of bristles 12 is prevented via the inner end face 12b, since this is sealed liquid-tight by gluing, welding or a corresponding measure. The liquid then flows along the wick body 13 and enters the bristle bundle 12 in the radial direction via the cylindrical outer surface.

A schematic representation of the liquid transfer from the wick body 13 into the bristle bundle 12 is shown in FIGS. 8a and 8b. The wick body 13 with fibers oriented in the longitudinal direction is supplied with liquid from the storage (not shown). This is due to the capillary action on the cylindrical boundary or lateral surface to the bristle bundle 12. Since the individual bristles of the bristle bundle 12 do not lie completely close to one another, the liquid also penetrates the bristle bundle 12. In addition, there are capillary forces in the radial direction, which arise from the capillary pressure in the gaps between the individual bristles. In the interior of the bristle bundle 12, the capillary pressure in the channels formed by the individual bristles generates capillary forces in the longitudinal direction of the bristles. If necessary, supported by gravity, they ensure that the liquid is transported to the nib where it is dispensed. Thus, the writing tip of the bristle bundle 12 is always adequately supplied with liquid.

The channels between the individual bristles are changed by a flexing deformation of the writing tip when writing, painting or applying, whereby a dosing of the liquid flow is generated by changing the capillary forces.

In the case of a wick body 13 made of an oriented fiber fleece, the individual fibers are connected to one another at many points along their length, for example resinified. This causes a throttling effect in the liquid flow. In addition, the wick body 13 is usually not deformed when the device is actuated, so that irrespective of the use of the device for the wick body, there is a constant dispensing characteristic with regard to the liquid to the bristle bundle. In contrast, the liquid in the bristle bundle is subject to a significantly lower throttling compared to the wick body, since the individual bristles are not connected to one another. When the device is actuated, the writing tip is deformed, as a result of which a metering of the liquid flow, i. H. a release of the liquid and its replenishment results.

Claims (22)

Device for applying liquids, in particular a writing device, with a housing in which a storage for the liquid is formed and at least one bristle bundle arranged in an opening of the housing, by means of which the liquid flowing to it can be applied, characterized in that in the housing (11) a wick body (13) is provided, which is arranged in the flow direction immediately upstream of the bristle bundle (12; 17) and releases the liquid to the bristle bundle (12; 17), and that the bristle bundle (12; 17) at least partially in the wick body (13) is inserted. Device according to claim 1, characterized in that the wick body (13) is arranged between the reservoir and the bristle bundle (12; 17). Device according to claim 1 or 2, characterized in that the wick body (13) is connected to the storage device at its inner end. Device according to claim 1, characterized in that the wick body (13) forms the store. Device according to one of claims 1 to 4, characterized in that the bristle bundle (12; 17) is arranged at a distance from the inner end of the wick body (13). Device according to one of claims 1 to 5, characterized in that the bristle bundle (12) is held in a blind hole (14) in the wick body (13). Apparatus according to claim 6, characterized in that the blind hole (14) is formed in the central axis (S) of the wick body (13). Device according to claim 6 or 7, characterized in that the bristle bundle (12) is held in the blind hole (14) by means of a press fit. Device according to one of claims 6 to 8, characterized in that the bristle bundle (12) is held in a form-fitting manner in the blind hole (14) of the wick body (13). Apparatus according to claim 9, characterized in that an annular flange (15) is formed at the inner end of the bristle bundle (12) by melting the bristle ends, by means of which the bristle bundle is bumped into the blind hole. Device according to one of claims 1 to 10, characterized in that the housing (11) holds the wick body (13) under a radially inward bias. Device according to one of claims 6 to 11, characterized in that several blind holes (14) are provided, in each of which a bundle of bristles (12) is held. Apparatus according to claim 12, characterized in that four blind holes (14) are provided which are arranged uniformly over the cross section of the wick body (13). Device according to one of claims 1 to 4, characterized in that the bristle bundle (17) extends to the inner end of the wick body (13), the liquid from the wick body (13) penetrating into the bristle bundle (17) via the lateral surface of the latter . Apparatus according to claim 14, characterized in that the inner end face of the bristle bundle (17) is closed by gluing, welding, etc. Device according to one of claims 1 to 15, characterized in that the bristle bundles (12) are brought together towards their free ends. Apparatus according to claim 11, characterized in that the wick body (13) near the opening of the housing has a peripheral peripheral recess (16) and the bristle bundle (17) in the recess (16) between the wick body (13) and the edge of the Opening of the housing (11) is held. Apparatus according to claim 17, characterized in that the bristle bundle (17) has a cavity at least in the region projecting beyond the wick body and the bristles converge to a tip (P) on the central axis (S) of the wick body (13). Device according to one of claims 1 to 18, characterized in that the wick body (13) consists of fleece, felt or cotton. Device according to one of claims 1 to 19, characterized in that the wick body (13) consists of an absorbent plastic foam and is foamed onto the bristle bundle (17). Device according to one of claims 1 to 19, characterized in that the wick body (13) consists of extruded capillary profiles. Device according to one of claims 1 to 21, characterized in that the wick body (13) essentially has fibers oriented in its longitudinal direction.

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