Abstract:
A device for applying a fluid, notably a writing pen or cosmetic pencil, includes a tubular shaft, a fluid container that is positioned therein, a tip, and a conducting system for the fluid. The container ensures constant pressure equalization with the atmosphere by having its front and rear ends each being fluidically connected to the atmosphere. At the rear end of the container a ventilation opening is positioned. The ventilation opening opens into the container interior containing the fluid and is sealed by a semi-permeable membrane.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of copending International Application No. PCT/EP00/03434, filed Apr. 15, 2000, which designated the United States. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to an implement for applying a fluid, in particular, a stick-like writing or cosmetics implement. Such a prior art application implement, for example, is disclosed in German Patent DE 3910787 C1, the implement having a sleeve-like shank. A container for accommodating a fluid is disposed in the shank. Also provided is a fluid-directing system that, on one hand, bears a writing tip and, on the other hand, is in contact with the interior of the fluid container. The front end of the container is in fluidic connection with the atmosphere through an air-admission opening that is closed off by a semi-permeable diaphragm. As a result of which, air admission to, and air extraction from, the container is achieved with the writing tip retained in the upward direction. To ensure air admission and air extraction (for simplicity, reference is only made to air admission hereinbelow) in the case of an application implement with the writing tip retained in the downward direction, the prior art application implement has a transverse wall drawn into the container that includes, at least in part, a semi-permeable diaphragm that is impermeable to fluid and is permeable to air and water vapor. The transverse wall is joined, on the shank side, by a pressure-equalization chamber that is subdivided by a lip-valve-bearing transverse wall. Finally, an air-admission opening is provided in the shank-side or rear end wall of the container. 
     British Patent Document GB 715,043 discloses a ballpoint pen in which the fluid container is connected to the atmosphere by way of its rear end through a semi-permeable diaphragm. The diaphragm includes a non-porous elastic material, e.g., of latex, and allows the through-passage of air on account of molecular diffusion. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the invention to provide an application implement that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that, with a straightforward construction, has a container that ensures constant pressure equalization with the atmosphere with the writing tip retained in the downward direction, that is to say during use, and with the writing tip retained in the upward direction as well as in the case of all other conceivable storage and use positions. 
     With the foregoing and other objects in view, there is provided, in accordance with the invention, an implement for applying a fluid, including a sleeve-like shank having a container, the container having an interior accommodating a fluid, a front end, a rear end, at least one of the front end and the rear end fluidically connected to the atmosphere for admitting air into and extracting air from the interior, and at least one air-admission opening connecting the interior to the atmosphere, a diaphragm permeable to air and impermeable to the fluid, the diaphragm closing off the air-admission opening, a writing tip of a capillary material, the tip connected to the shank, and a fluid-directing system fluidically connecting the writing tip to the fluid in the interior with the capillary material, the fluid-directing system directing fluid from the interior of the container to the writing tip. Preferably, the implement is a stick-like writing or cosmetics implement. 
     In accordance with another feature of the invention, the air-admission opening is disposed at the rear end of the container. 
     According to the application implement of the invention, there is disposed, at the rear end of the container, an air-admission opening that opens out directly into the fluid-containing container interior and is closed off by a semi-permeable diaphragm, i.e., one that is permeable to air and is impermeable to fluid. The construction makes it possible for the interior of the shank to be utilized to better effect and, thus, for a larger quantity of fluid to be stored. In the application implement disclosed from German Patent DE 3910787 C1, an air chamber is provided in the container, to the detriment of the quantity of fluid that can be stored. It has been found that the air admission in the writing position is possible even without an air-filled auxiliary chamber with lip valves disposed therein. The absence of such a construction feature simplifies the production of the application implement. 
     In accordance with a further feature of the invention, there is provided a second diaphragm permeable to air and impermeable to the fluid. The air-admission opening includes an air-admission opening at the front end, and the second diaphragm closes off the air-admission opening at the front end. 
     The air admission to the application implement with the writing tip retained in the upward direction preferably takes place through at least one air-admission opening that is disposed at the front end of the container and is likewise closed off by a semi-permeable diaphragm. The diaphragms are disposed, for example, adhesively bonded, on the outside or inside of the respective container wall having the air-admission opening. A configuration that further simplifies the production provides that the component having the air-admission opening is an injection molding with a diaphragm molded therein. It is, thus, possible for the container as a whole to be provided with the diaphragm during its production. As a result, there is no need for the diaphragm to be fixed subsequently on the container. 
     In accordance with an added feature of the invention, the container has a container wall with an inside surface and an outside surface, and the diaphragm and the second diaphragm are each disposed on one of the group consisting of the outside surface and the inside surface. 
     In accordance with an additional feature of the invention, the container is made by injection molding with the diaphragm molded therein. 
     In accordance with yet another feature of the invention, the container is made by injection molding with at least one of the diaphragm and the second diaphragm molded therein. 
     In a configuration that simplifies the production and the assembly, the fluid-directing system includes a tube with an essentially radially projecting flange that forms the front end wall of the container. The tube, the flange, and the container are preferably integral. As a result, on one hand, the assembly is facilitated and, on the other hand, leakages between the flange and container are avoided. 
     In accordance with yet a further feature of the invention, the fluid-directing system has a tube with a substantially radially projecting flange, and the flange forms a front end wall of the container. 
     In accordance with yet an added feature of the invention, the tube, the flange, and the container are integral and/or are formed in one piece. 
     In accordance with yet an additional feature of the invention, the circumferential wall of the container is formed by the shank itself, which reduces the number of parts and, thus, the assembly outlay. 
     In accordance with again another feature of the invention, the shank has a rear end and an outside, a stopper has an inside and closes off the rear end of the shank, and an air-admission channel fluidically communicating with the atmosphere is disposed between the inside of the stopper and the outside of the shank. 
     In accordance with again a further feature of the invention, a separate container is disposed in the shank. The air admission to the container through a diaphragm disposed at the rear end of the container is made possible in that an air channel that communicates with the diaphragm is provided between the outside of the sleeve and the inside of the shank. 
     In accordance with again an added feature of the invention, the container has an outer surface, the shank has an inner surface, the at least one air-admission opening is at least one rear air-admission opening, and an air channel is disposed between the outer surface of the container and the inner surface of the shank and fluidically communicates with the at least one rear air-admission opening. 
     In accordance with again an additional feature of the invention, the air channel opens out into a cavity that is connected to the atmosphere and is disposed between the tube of the fluid-directing system and an essentially sleeve-like tip part that encloses the fluid-directing system at a radial spacing therefrom. In the case of the separate container, an air-admission opening may be provided in the circumferential wall of the container. The configuration is associated, first of all, with the advantage that the air-admission opening may be of larger configuration than in the case of a configuration in an end wall of the container. In the case of the front end wall, in particular, the end-wall surface area available for air-admission openings is small because a bore has to be provided here through which the fluid-directing system can remove fluid from the container. 
     In accordance with still another feature of the invention, the air-admission opening in the circumferential wall of the container is at least one elongate air-admission opening extending from the front end of the container to the rear end of the container. 
     It is particularly advantageous if at least one elongate air-admission opening extends from the tip end of the container to the shank end of the latter. The configuration ensures air admission more or less in every position of the stick-like implement, particularly if a plurality of such elongate air-admission openings distributed over the container circumference is provided. It is possible to achieve the same effect as with the plurality of elongate air-admission openings if one air-admission opening extends helically over the container circumference. In such a case, as is also the case with the plurality of rectilinear elongate air-admission openings, air admission to the interior of the container is also possible in any desired rotary position—in relation to the longitudinal axis of the application implement as axis of rotation. 
     In accordance with still a further feature of the invention, the container is an exchangeable cartridge. 
     In accordance with still an added feature of the invention, the cartridge has a front end wall defining a central opening, the fluid-directing system has a tube with a rear end, and the rear end of the tube is inserted releaseably into the central opening. 
     In accordance with still an additional feature of the invention, the fluid-directing system has a tube with an interior having an inner cross-section, the writing tip has a rear longitudinal section disposed in the tube, an insert is disposed in the interior of the tube and narrows the inner cross-section to form at least one longitudinally extending fluid channel in the interior of the tube, and the fluid channel adjoins the writing tip and fluidically communicates with the atmosphere for admitting air into and extracting air from the front end of the container. 
     In accordance with still another feature of the invention, the tube has an inner tube wall, the insert has a circumferential section abutting the inner tube wall, and at least one flattened portion disposed at a distance from the inner tube wall, and the inner tube wall and the flattened portion define the fluid channel. 
     In accordance with a concomitant feature of the invention, the fluid channel has a cross-sectional surface area decreasing in a direction of the container. 
     In a further inventive configuration, an insert that narrows the interior of the tube of the fluid device is disposed in the interior. The narrowing in cross-section makes it possible to produce axially running fluid channels that are considerably larger than the capillaries of a fibrous or sintered material and, thus, subject the fluid to a smaller capillary pressure. The high capillary pressure of the conventional materials involves the risk, in the case of application implements with free fluid stores, of fluid dripping out of the writing tip retained in the downward direction. Such a risk is prevented by the proposed configuration of the fluid-directing system. With the writing tip retained in the upward direction, it is possible to dissipate heating-induced pressure in the container through a fluid channel and an air channel provided between the writing tip and the inner wall of the tube. Conversely, air can penetrate into the container through the same route. It is, thus, possible to dispense with a diaphragm-closed air-admission opening in the front container region. 
     Other features that are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in an application implement, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary, longitudinal, cross-sectional view of a first embodiment of an application implement according to the invention; 
     FIG. 2 is an enlarged, fragmentary, cross-sectional view of the detail II of FIG. 1; 
     FIG. 3 is a fragmentary, longitudinal, cross-sectional view of a second embodiment of the application implement of FIG. 1; 
     FIG. 4 is an enlarged, cross-sectional view of the embodiment of FIG. 3 across line IV—IV; 
     FIG. 5 is an enlarged, cross-sectional view of the embodiment of FIG. 3 across line V—V; 
     FIG. 6 is an enlarged, fragmentary, cross-sectional view of the detail VI in FIG. 3; 
     FIG. 7 is an enlarged, fragmentary, cross-sectional view of the detail VII in FIG. 3, 
     FIG. 8 is a fragmentary, longitudinal, cross-sectional view of a third embodiment of the application implement of FIG. 1; 
     FIG. 9 is an enlarged, cross-sectional view of the embodiment of FIG. 8 across line IX—IX; 
     FIG. 10 is an enlarged, fragmentary, cross-sectional view of the detail X in FIG. 8; 
     FIG. 11 is an enlarged, fragmentary, cross-sectional view of a shank end of the application implement according to FIG. 3 with an alternative diaphragm embodiment; 
     FIG. 12 is an enlarged, fragmentary, cross-sectional view of a shank end of the application implement according to FIG. 3 with a second alternative diaphragm embodiment; 
     FIG. 13 is a fragmentary, longitudinal, cross-sectional view of a fourth embodiment of the application implement of FIG. 1 with an alternative embodiment of air-admission openings disposed in a circumferential wall of a fluid container; 
     FIG. 14 is an enlarged, fragmentary, cross-sectional view of the detail XIV of FIG. 13; 
     FIG. 15 is a fragmentary, longitudinal, cross-sectional view of a fifth embodiment of the application implement of FIG. 1 with another alternative embodiment of air-admission openings; 
     FIG. 16 is a fragmentary, longitudinal, cross-sectional view of a sixth embodiment of the application implement of FIG. 1 with a further alternative embodiment having a single air-admission opening extending from a shank end to another end of a fluid container; 
     FIG. 17 is a fragmentary, longitudinal, cross-sectional view of a seventh embodiment of the application implement of FIG. 1; 
     FIG. 18 is an enlarged, cross-sectional view of the embodiment of FIG. 17 across line XVIII—XVIII; and 
     FIG. 19 is an enlarged, fragmentary, cross-sectional view of the detail XIX of FIG.  18 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof and also the other exemplary embodiments, there is shown essentially a sleeve-like shank  1 , a fluid-directing system  3 , which retains a writing tip  2 , and a sleeve-like tip part  4 , which encloses the fluid-directing system  3  at a radial spacing therefrom. The shank  1  itself forms a container  5  for a writing fluid or for a cosmetics fluid. The rear end of the shank  1  has a region  7  that is drawn radially inward and onto which an essentially cup-like stopper  8  is fitted. The stopper  8  is fixed on the shank preferably by adhesive bonding or ultrasonic welding. Within the region  7 , an end wall  11  is integrally formed on the inner surface  10  of the shank. The inner wall  10  extends radially inward and has a central air-admission opening  12  passing through it. A semi-permeable diaphragm  13  is fixed on the outside of the end wall  11 . The outside is directed away from the writing tip  2 . The axial spacing between the end wall  11  and the base  14  of the stopper  8  is dimensioned such that there is also an axial spacing or a cavity  15  provided between the diaphragm  13  and the base  14 . The cavity  15  communicates with the atmosphere through an air-admission channel  16 , which is disposed between the stopper  8  and the narrowed region  7  of the shank  1 . The stopper  8  butts by way of its end side  17 , against a radially outwardly extending radial shoulder  18  of the shank  1  (see FIG.  2 ). In the region of the air-admission channel  16 , a groove  19  is made in the end side  17 . The groove  19  connects the air-admission channel  16  to the atmosphere. The air-admission channel  16  is connected to the cavity  15  through at least one groove  20  in the end side  9  of the shank  1 . 
     The diaphragm  13  prevents fluid from being able to pass out of the container  5 . However, the diaphragm  13  allows air admission to the container in the direction of the arrow  21  when the fluid supply decreases during use of the application implement, that is to say in the writing position of the implement. With the container contents heating up in such a position, air can escape outward, in the opposite direction, into the atmosphere. It is, thus, possible for constant pressure equalization to take place in the container  5  during use of the application implement. 
     The front end of the container  5  is closed off by a flange  23 , which is part of the fluid-directing system  3 . Integrally formed on that side of the flange  23  that is oriented away from the writing tip  2  is a tube section  24  that extends into the shank  1  and butts against the inner surface  10  of the shank by way of its outer surface  25 . The connection between the tube section  24  and the shank  1  takes place, for example, through adhesive bonding. The tube section  24  is offset radially inward to such an extent that the outer surface  26  of the shank  1  is aligned with the border surface  27  of the flange  23 . Integrally formed on the other side of the flange  23  is a further tube section  28 , of which the outer surface  29  is aligned with the border surface  27 . The tip part  4  has its rear end positioned in the tube section  28  and encloses a tube  30 , integrally formed on the flange  23 , at a radial spacing therefrom. At the front side of the tube  30  is the writing tip  2 . In the region of the tube  30  that adjoins the writing tip  2  is a capillary material  33  formed, for example, from plastic fibers or a sintered plastic. The tube  30 , flange  23 , and capillary material  33  together form the fluid-directing system. The capillary material  33  is in fluidic connection with the interior of the container  5  through a central through-passage opening  34  in the flange  23 . The front region  35  of the tip part  4  tapers conically in the direction of the writing tip  2  and is connected integrally, at its front end, to a tube section  36 , which encloses the tube  30 . Disposed between the tube  30  and the tube section  36  is an air-admission channel  37  that connects the interior of the tip part  4 , or the cavity  38  disposed between the tip part  4  and the tube  30 , to the atmosphere. 
     Finally, a plurality of air-admission openings  39  is also provided in the flange  23 . The openings  39  widen radially in a step-like manner in the direction of the writing tip  2 . A semi-permeable diaphragm  40  is inserted into the radially widened opening region in each case. The diaphragm  40  is fixed on the flange  23 , or in the widened region of the air-admission opening  39 , for example, by adhesive bonding. 
     If the writing implement illustrated in FIG. 1 is retained with the writing tip  2  in the upward direction, an air cushion forms in front of the air-admission openings  39 . In the case of heating-induced expansion of such an air cushion, air can pass, through the air-admission openings  39  and the semi-permeable diaphragms  40 , into the cavity  38  and, from there, into the atmosphere through the air-admission channel  37 , provided the protective cap  42  that is customary for application implements of the present type has been removed. 
     In the exemplary embodiment according to FIG. 3, the fluid container  5   a  is formed by a separate sleeve inserted into the shank  1   a . The rear end of the sleeve is directed away from the writing tip  2 , has an end wall  45  that is spaced apart from the end side  43  of the sleeve, and is provided with a central air-admission opening  12   a . A semi-permeable diaphragm  13   a  is embedded, by way of its border regions, in the end wall  45 , which projects radially inward in the manner of an annular protrusion. An axial spacing, and, thus, a cavity  47 , is provided between the end wall  45  or the diaphragm  13   a  and the base  46  of the shank  1   a . The cavity  47  is connected, through at least one groove  48  in the end side  43  of the container  5   a , to an air-admission channel  49 , which is provided between the outside  50  of the container  5   a  (see FIG. 6) and the inner surface  10   a  of the shank  1  and extends axially or in the direction of the center longitudinal axis  51  of the application implement. The air-admission channel  49  may extend over the entire circumference of the container  5   a . It is also conceivable, however, for the outside  50  to be provided with a plurality of non-illustrated grooves extending in the direction of the center longitudinal axis  51 . 
     The front end wall of the container  5   a  is formed by a flange  23   a , which is part of the fluid-directing system  3 . The flange  23   a  is inserted into an accommodating groove  53  at the front end of the container  5   a  and is, for example, adhesively bonded or ultrasonically welded there. The tube  30   a  projects from the front side of the flange  23   a  and is in fluidic connection with the container  5   a  through a through-passage opening  34   a  in the flange  23   a . The tube  30   a  bears the writing tip  2  at its front end and is likewise filled with a capillary material  33 . 
     The tip part  4   a  has its shank end side butting against the end side of the container  5   a . The fluidic connection between the air-admission channel  49  and the cavity  38  takes place through a groove  54  in the end side of the tip part  4   a , the end side being directed away from the writing tip  2 . See also FIGS. 4 and 6. The flange  23   a  has a total of three air-admission openings  39   a , approximately the form of circle arcs, passing through it. In each case, one diaphragm  40   a  is inserted into the air-admission openings  39   a , the diaphragm  40   a  being embedded, by way of its border region, in the plastic material of the flange  23   a , that is to say, being encapsulated by the injection-molded plastic material thereof. As can be gathered from FIG. 5, in particular, the air-admission channel  49  encloses the container  5   a  over its entire circumference. Each air-admission opening  39   a  is assigned a groove  54 . See FIG.  4 . 
     In the exemplary embodiment illustrated in FIG. 8, the container  5   b  is configured as an exchangeable cartridge. The rear end of the container  5   b  is configured similarly to the rear end in the exemplary embodiment according to FIG. 3, although the semi-permeable diaphragm  13   b  is fixed on the outside of the end wall  45 . A flange  57  forms the tip end wall of the container  5   b . The flange  57  has a first longitudinal section  57   a  and a second, radially widened longitudinal section  57   b . See FIG.  10 . The section  57   a  butts against the inner surface  60  of the container. The second longitudinal section has the section  57   b , which projects radially beyond the first longitudinal section  57   a , positioned in a recess  58  in the end side  59  of the container  5   b . Provided in the flange  57  are two diametrically opposite air-admission openings  39   b , which merge into a radially widened region  63  in the direction of the writing tip  2 . The region  63 , just like the air-admission opening  39   b  as a whole, is circular in cross-section and extends as far as the border  64  of the flange  57 . See FIG. 9 in particular. In each case, one semi-permeable diaphragm  40   b  is inserted into the radially widened region  63  of the air-admission openings  39   a.    
     A central through-passage opening  66  is provided in the flange  57  and continues into the interior of a tube section  67 , which projects from the flange on the tip side. The tube  30   b  is positioned in the tube section  67  and is supported thereon by way of a flange  69  projecting radially outward from its circumference. The tip part  4   b  is fitted over the flange  69 , and fixed thereon, by way of a longitudinal section  70  that is widened radially inward. An air-admission channel  49  that is configured in the same way as in the exemplary embodiment according to FIG. 3 is provided between the container  5   b  and the shank  1   b . A radial spacing  72  is provided between the mutually facing end sides of the container  5   b  and the tip part  4   b  and creates a connection between the air-admission channel  49  and the space  73  provided between the two flanges  69 ,  57 . The space  73  is connected, through bores  74  in the flange  69 , to the cavity  38  enclosed by the tip part  4   b , the cavity  38 , in turn, communicating with the atmosphere through the air-admission channel  37 . 
     FIGS. 11 and 12 illustrate further possible ways of configuring a semi-permeable diaphragm and of fixing the same on an end wall. According to FIG. 11, the diaphragm  13   c  is a sheet that is fixed on the outside of the end wall  45 , for example, by adhesive bonding. In the exemplary embodiment according to FIG. 12, the diaphragm  13   d , formed, for example, likewise as a sheet, is fixed in a retaining ring  75  by way of its border. The retaining ring  75  is fastened on the outside of the end wall  45 . The method of configuring and fixing the diaphragms  13   c ,  13   d  that is illustrated in FIGS. 11 and 12 may obviously be applied to all air-admission openings, on the outside and inside, of an application implement. 
     The exemplary embodiment according to FIG. 13 is an application implement in which a separate container  5   c  is disposed in a shank  1   c , an air-admission/extraction channel  49  being left free in the process. The container  5   c  is closed off at its rear end by an integrally formed end wall  76 . The front end wall is formed by a flange  77 , which is integrally formed at the rear end of the tube  30   c . In the circumferential wall of the container  5   c , at least one air-admission opening  39   c  is disposed in the front region and at least one air-admission opening  12   c  is disposed in the rear region. The air-admission openings  39   c ,  12   c  are configured in the manner of slots and extend in the direction of the center longitudinal axis  51 . The air-admission openings  39   c ,  12   c  are closed off by semi-permeable diaphragms  40   c ,  13   e  and communicate with the air-admission channel  49 . The mutually facing end sides of the tip part  4   c  and the container  5   c  butt against one another. In order to create a fluidic connection between the cavity  38  and the air-admission channel  49 , a groove  83  is provided in that end side of the tip part  4   c  that is directed toward the container  5   c . The flange  77  is inserted into the container  5   c  by way of a first longitudinal section  84 . See FIG. 14. A second, radially outwardly widened longitudinal section  85  is positioned in an accommodating groove  86  in the front end side  87  of the container  5   c.    
     In the exemplary embodiment illustrated in FIG. 15, in each case a plurality of air-admission openings  39   d ,  12   d  are provided in the front and rear regions of the container  5   d . The air-admission openings  39   d ,  12   d  likewise are configured in the form of slots, but extend in the circumferential direction, and are closed off by semi-permeable diaphragms  40   d ,  13   f . The rest of the configuration of the application implement from FIG. 15 corresponds to that from FIG.  13 . In the application implement according to FIG. 16, finally, a single air-admission opening  88  is provided extending from the front container region to the rear container region and likewise is configured in the form of a slot. The air-admission opening  88  extends obliquely in relation to the center longitudinal axis  51 , or runs helically, and is closed off by a semi-permeable diaphragm  89 . The diaphragm  89 , in the same way as those described above, is a thin sheet, a woven fabric, a sintered material, or a combination of these materials. 
     The exemplary embodiment according to FIG. 17 corresponds essentially to that from FIG. 13, although air admission to the container  5   e  in the front region thereof takes place through the fluid-directing system  3   d  rather than through an air-admission opening or semi-permeable diaphragm. Accordingly, the fluid-directing system is configured differently. The tube  30   d  bears the writing tip  2  in its front region, which is widened radially from the inside. The writing tip  2  is supported, by way of its rear end side  90 , on an inwardly projecting radial shoulder  91 . Positioned in that region of the tube  30   d  that adjoins the radial shoulder  91  in the rearward direction is a cylindrical insert  92 , of which the circumferential surface is configured in a manner complementary to the inner surface of the tube  30   d . Flattened portions  93  (see FIGS. 18,  19 ), however, are provided in the circumferential surface of the insert  92  and extend axially over the entire length of the insert. Together with the inner surface of the tube  30   d , the flattened portions bound fluid channels  94 . Through the fluid channels  94 , fluid can pass from the container  5   e  to the writing tip  2 . The writing tip is a capillary material and absorbs the fluid more or less in itself. The fluid channels  94  subject the fluid to a considerably lower level of capillary action than conventional materials used for fluid-directing systems, for example, fibrous materials or sintered materials. The capillary pressure that feeds the fluid in the direction of the writing tip with the tip retained in the downward direction is, thus, reduced, and fluid is prevented from dripping out in the case of the application implement being in the above-mentioned position. The flattened portions  93  may extend parallel to the center longitudinal axis  51 . It is also conceivable, however, for them to diverge slightly in the direction of the shank  1   e . Thus, the cross-sectional surface area of the fluid channels  94  decreases in the direction of the container  5   e . Accordingly, their capillary action in relation to the fluid increases. By virtue of such a configuration, it is, thus, possible to produce a capillary action in the direction of the container and, therefore, to restrict further the inflow of fluid to the writing tip  2 . In the case of the extraction of air with the writing tip retained in the upward direction, the fluid channels  94  are initially still filled with fluid. As soon as a pressure builds up in the container, however, the fluid is displaced from at least one fluid channel. As a result, an air-extraction channel is then available. To create a connection between these channels and the atmosphere, non-illustrated air-extraction channels may be provided between the outer circumference of the writing tip and the tube  30   d . The air extraction may also take place, however, through free capillaries of the writing tip. 
     The insert  92  need not necessarily extend as far as the rear end of the tube  30   d . It preferably has a length of 5 to 30 mm. Its diameter varies between values of 2 mm and 5 mm. The height  95  of a fluid channel  94  is preferably in the range of from 0.02 to 0.10 mm. The width  96  of the flattened portions  93  is obtained from the respective diameter of the insert  92 .