Filling system for fountain pens

Abstract

A filling system for a fountain pen is proposed, comprising a pump unit, an air passage connected to a first connection for connecting to the pump unit and the fountain pen, and an ink passage connected to a second connection for connecting to the fountain pen and separated from the air passage, the ink passage having an immersion end for immersion in ink, the pump unit being configured to introduce a predetermined volume of air into the air passage with an overpressure to flush the ink from the fountain pen, and subsequently apply a negative pressure to the air passage, whereby a predetermined volume of ink is sucked from the ink passage into the fountain pen.

Description

[Technical Field]

[0001] The present invention relates to a filling system for a fountain pen, to a writing instrument system having a filling system, and to a fountain pen, and to a method of filling a fountain pen. [Background technology]

[0002] Fountain pens are known that have an integrated ink reservoir with a piston, which can be filled by dipping the writing tip into an ink reservoir and moving the piston to draw in ink. Dipping wets the writing tip with ink, so the filling process always leads to the writing tip becoming soiled with ink. Therefore, the writing tip always has to be cleaned again.

[0003] In some cases, especially in the case of high-value fountain pens, it may be advisable to clean the ink-carrying passages to ensure continued proper functioning. This can be done, for example, by flushing the fountain pen with a liquid, for example distilled water. Summary of the Invention

[0004] The object of the present invention is to propose an alternative filling system for fountain pens, which makes filling the fountain pen as comfortable and clean as possible without soiling the writing tip.

[0005] This problem is solved by a filling system for a fountain pen with the features of independent claim 1. Preferred embodiments and developments emerge from the dependent claims and the following description.

[0006] A filling system for a fountain pen is proposed, comprising a pump unit, an air passage connected to a first connection for connecting to the pump unit and the fountain pen, and an ink passage connected to a second connection for connecting to the fountain pen and separated from the air passage, the ink passage having an immersion end for immersion in ink, the pump unit being configured to introduce a predetermined volume of air into the air passage with an overpressure to flush the ink from the fountain pen, and subsequently apply a negative pressure to the air passage, whereby a predetermined volume of ink is sucked from the ink passage into the fountain pen.

[0007] A pump unit, within the meaning of the present invention, is understood to be a device configured for pumping a fluid. As explained above, the fluid may in particular be air. It is expedient to configure the pump unit so that it can be placed on the ink container. The pump unit may therefore be embodied in the form of an ink container mount. However, other embodiments are also conceivable, in which it can be integrated directly into the ink container or its lid. In another variant, the pump unit need only be connectable to the ink container and may be manufactured separately from it. The ink container may, for example, be an inkwell typically used for filling fountain pens. The ink container may be made of glass and may have an opening that can be closed by a screw cap. The pump unit may be adapted to be placed on such an inkwell, for example, by unscrewing the cap. The pump unit may then be screwed onto the external thread of the ink container, thereby ensuring a secure attachment of the pump unit to the ink container during the filling time. Alternatively, it is conceivable to provide the ink container with a pump unit directly, in which case the pump unit is permanently mounted on the ink container and optionally closable by a cap, and the pump unit could then be slightly pressed or snapped into the ink glass opening.

[0008] Here, it is assumed that the fountain pen is connected to the air passage so that a first end or a first incision of the ink tank inside the fountain pen is fluidly connected to the first connection. A second end or a second incision opposite the first end of the ink tank can be fluidly connected to the ink passage. Thus, when air is introduced into the air passage with overpressure, the ink in the fountain pen's ink tank is flushed out through the ink passage and into the ink container connected to the pump unit. Preferably, the ink tank is completely emptied after the air volume is introduced. Therefore, by subsequently applying a negative pressure to the air passage, air is again sucked into the pump unit through the air passage. As a result, ink is sucked from the ink passage into the ink tank upon connection of the fountain pen to the ink tank. Ink flows through the ink passage into the ink tank, filling it accordingly. For this purpose, the ink passage has an immersion end that is provided for immersion in ink.

[0009] It is advisable to design the connection for connection to the fountain pen as simply as possible. For example, it may be advantageous to make it as a small tube or tube end, and for connection, it is only necessary to screw on a corresponding connection on the fountain pen. Thus, for example, it is only necessary to open the lid or housing part, then screw the fountain pen on the connection, and then unscrew it again in the opposite direction after the filling process.

[0010] The air volume and ink volume are then preferably adjusted to the fill volume of the ink tank, thereby achieving complete filling of the ink tank. This filling system is therefore a very comfortable and clean means for refilling the ink tank of a fountain pen adapted for use with the filling system, without the need to immerse the writing tip in the ink well.

[0011] The pump unit may be mechanically or electrically constructed, with a mechanical embodiment having, for example, a moving piston for pumping, and an electrical embodiment being, for example, in the form of an electrical metering pump.

[0012] In a particularly preferred embodiment, the pump unit comprises a cylinder having a bottom area and an opening facing away from the bottom area, a piston arranged axially movably within the cylinder, and a spring member driving the piston toward the opening, wherein the air passage extends from an air chamber formed between the piston and the bottom area through the piston, the ink passage extends through the bottom area and the piston, and the piston is radially sealed against the cylinder, whereby pressing the piston toward the bottom area generates an overpressure acting on the first connection, and releasing the piston generates a negative pressure acting on the first connection.

[0013] As the piston moves within the cylinder, air is guided into the air passage. This can be done, for example, by pressing the piston toward the bottom area, thereby shrinking the air chamber there. A spring element is provided to move the piston again in the other direction. Releasing the piston thus leads to an expansion of the volume of the air chamber, thereby generating a negative pressure. This leads to air being sucked back into the air chamber via the air passage. Due to the fluid connection with the ink passage provided in the fountain pen, this results in ink flowing back into the ink passage via the ink passage. The ink tank is thus filled. The stroke of the piston and the volume difference of the air chamber are preferably adjusted to the filling volume of the ink tank, thereby achieving complete filling of the ink tank.

[0014] The pump unit cylinder may have at least one cylindrical bore extending from the opening toward the bottom section, which can be understood as the lower end of the cylinder facing away from the opening. In a simple case, the bottom section may have only a flat surface. In another case, one or more steps may be provided, which reduce the internal diameter of the cylinder in at least a partial region.

[0015] The piston has an outer diameter adapted to the inner diameter of the cylinder. A corresponding snug fit between the piston and the cylinder may be intended to allow the piston to slide easily within the cylinder. Furthermore, the inner wall of the cylinder could have a sliding coating.

[0016] The spring element is configured to exert a constant force on the piston, thereby urging it away from the bottom area. This may be, for example, a compression spring arranged between the bottom area and the piston. Alternatively, it may be a tension spring or other device arranged in the area of ​​the cylinder facing away from the bottom area and pulling the piston back toward the opening. The spring element may be made of metal, plastic, or a naturally occurring material, such as rubber. The compression spring may be made of a metal material or plastic, in particular. The tension spring may also be made of rubber in the form of one or more tension elements. The spring element allows the piston to be positioned in a neutral position, in which the user can connect the fountain pen to the connection, for example, by snapping it in place. The user can then press the fountain pen to push the piston toward the bottom area, which activates the filling system, and the piston is returned to its neutral position by the compression spring when the fountain pen is released. Both paths are important for this function.

[0017] An air passage could extend from the first connection through the piston into the air chamber. Movement of the piston towards the bottom area generates an overpressure in the air chamber due to the radial seal between the piston and the cylinder. The air passage communicates with the air chamber, so that the overpressure passes through the air passage into the first connection. It is contemplated that the fountain pen can be connected to the air passage, and for this purpose it may have a small tube or other conduit extending, for example, into the ink tank of the fountain pen.

[0018] The ink passage could extend beyond the bottom area. When the pump unit is placed on top of the ink container, the ink passage could extend into it, e.g., into the ink volume therein. The ink passage could be connected to a second conduit of the fountain pen. This second conduit is preferably fluidly connected to the first conduit, e.g., by an ink tank placed in the fountain pen. To this end, both connections could be connectable to opposite ends of the ink tank.

[0019] The immersion end is provided so that it can penetrate into the ink of the ink container. It could extend from the piston through or protrude through the bottom area, for example. Alternatively, the immersion end could be guided in a different manner than protruding through the bottom area. For this purpose, a flexible connecting line is suitable, which moves with the piston at one end and is at least substantially fixed at the opposite end.

[0020] In order to prevent overpressure from building up in the ink container, a ventilation opening, for example in the form of one or more openings, may be provided between the ink container and the pump unit, which may for example be embodied as a slit or bore in the step where the pump unit rests on the ink container.

[0021] In a preferred embodiment, the spring element is a compression spring and is disposed between the bottom section and the piston. The bottom section may have recesses or cutouts into which the ends of the compression spring can be inserted. Similarly, the piston may have cutouts, grooves, or other recesses into which the opposing ends of the compression spring can be accommodated. It is particularly preferred that the compression spring is a coil spring or a conical spring, which can move the piston away from the bottom section. Unintentional ejection of the piston is substantially achieved by a form-fitting mechanism. Each end of the compression spring may be exposed and centered, for example, by positioning in a recess or other geometric feature. However, it would also be possible to fix the spring element at both end faces, making it impossible to pull or eject the piston from the cylinder. For example, the compression spring may be glued on both sides. The spring constant is preferably adapted so that the user can easily push the piston in without the compression spring providing excessive resistance. Similarly, the compression spring should be rigid enough to allow the user to easily fit the fountain pen onto the connection without the piston already moving.

[0022] In a preferred embodiment, the piston has a first sealing body arranged on the side facing the bottom area. The first sealing body may be, for example, annular and may surround a portion of the piston. It may be, for example, form-fittedly connected to the piston. However, adhesive or other bonding methods are equally possible. The first sealing body may have an outer radial protrusion that makes surface contact with the inner wall of the cylinder. Instead of one or more protrusions, the entire first sealing body may be in flush contact with the inner wall of the cylinder. This reliably prevents air from the air chamber from escaping through the piston and out of the filling system. The sealing body may be made of natural or synthetic rubber or a similar rubber-like material.

[0023] In a preferred embodiment, the immersion end is guided axially by a second sealing body arranged in the bottom section. This allows sealing of the air chamber in the area of ​​the bottom section without abandoning the fluid connection with the ink volume and ink passage. In one simple case, the second sealing body can be a sealing ring with an angular, circular, or X-shaped cross-section. Other cross-sectional shapes are also conceivable.

[0024] Furthermore, outside the neutral position of the piston, the seal area of ​​the immersion end can rest against the second seal body, and the immersion end has an overflow area, located adjacent to the seal area in the direction of the piston and having a tapered portion in at least a partial area for conducting ink from the air chamber through the bottom area. The overflow area is in its neutral position inside the second seal body, so that no seal is triggered against the immersion end when the piston is in its neutral position. In this neutral position, the piston is pressed toward the opening by a spring member. This allows ink in the air chamber to flow from the bottom area through the overflow area into the ink container. This may be necessary if, during filling of the fountain pen, too much ink is sucked from the ink container due to the piston stroke, and thus passes partially through the ink tank and completely into the air line. This could result in ink entering the air chamber and then flowing out. When the piston is pressed in the direction of the bottom area, the sealing area overlaps with the second sealing body and the air chamber is sealed again for the creation of the overpressure required for the filling process.

[0025] To ensure that the ink tank is always completely filled, the volume of the air chamber may be larger than the volume of the ink tank to be filled.

[0026] It is particularly preferred that the first and second connection parts can be made concentric with one another, so that the user cannot mistakenly fit the fountain pen into the first and second connection parts, since any rotational position is suitable for establishing a connection.

[0027] Furthermore, the first connecting portion could be located inside the second connecting portion and extend beyond the second connecting portion, which would simplify fitting the fountain pen and provide sufficient separation between both connecting portions.

[0028] In a preferred embodiment, the first and second connectors are arranged in an insertion sleeve located on the side of the piston facing away from the air chamber. The insertion sleeve may protrude from or be arranged within the top surface of the piston. The top surface is considered to be the surface of the cylinder facing away from the bottom area. The insertion sleeve allows for easy and intuitive insertion of the fountain pen into the filling system.

[0029] At least one third sealing body may be arranged between the insert sleeve and the piston, which seals the corresponding lines of the fountain pen for both connections, but may also be part of the fountain pen.

[0030] It is further preferred that the first section of the immersion end, located on the side of the bottom section facing away from the air chamber, has a larger outer diameter than the second section, which is located in the air chamber when the piston is in its neutral position. The larger outer diameter may form a step that can fit tightly onto the bottom section, for example, from below, i.e., from the side facing away from the air chamber. However, additional objects, such as seals or spacers, may be present between the bottom section and the first section of the immersion end. If the piston and the immersion end are appropriately dimensioned and adapted to each other, accidental withdrawal of the piston is possible and the opening and the piston can end up in the same plane.

[0031] In one embodiment, the air and ink passages could be arranged in the piston radially offset from one another at least in some areas, which can somewhat simplify the guidance of air and ink inside the piston.

[0032] The cylinder preferably has a step on its outer surface for resting it flush on the edge of the ink container opening. This allows for a harmonious unit between the cylinder and the ink container, particularly in high-value fountain pens. It is conceivable that the cylinder be adapted to be mounted directly on the ink container by means of a threaded ring. In that case, the filling system and the ink container form an interlocking unit. An additional cap could then be screwed onto the opening.

[0033] The present invention further relates to a writing instrument system, comprising a filling system based on the above description and a fountain pen, the fountain pen having a coupling mechanism and an ink tank having a first incision and a second incision, the coupling mechanism being connectable with the first incision and the second incision and connectable with the first connecting portion and the second connecting portion, thereby enabling fluid connections to be established between the first connecting portion and the first incision and between the second connecting portion and the second incision.

[0034] The present invention further relates to a method for filling a fountain pen, comprising the steps of connecting a first connection of a pump unit with a first opening of at least one ink tank in the fountain pen, connecting a second connection of the pump unit with a second opening of at least one ink tank in the fountain pen, immersing the second connection in ink from the ink container, introducing air with an overpressure into the first connection to expel ink in the at least one ink tank into the ink container via the second connection, and creating a negative pressure at the first connection to suck ink into the at least one ink tank via the second connection.

[0035] As explained above, this allows for complete filling of the ink tank of the fountain pen. The overpressure causes residual ink to be expelled from the ink tank via the second connection. Subsequent application of negative pressure, on the other hand, causes ink to be sucked into the ink tank via the second connection. To this end, the first connection may be connected to a pump unit configured to provide air with overpressure and subsequently with negative pressure. If the first and second incisions are located at opposite ends of the ink tank, the entire volume of the ink tank between them can be filled with ink. Furthermore, it is conceivable that at least one ink tank may have more than one ink tank, all of which are connectable to each other. The first and second incisions may be located at opposite ends of the entire ink tank structure, thereby filling the entire ink tank structure with ink in the manner described above.

[0036] In accordance with the above description, the introduction of air and the generation of negative pressure can be performed by a pump unit having a cylinder and a spring-loaded piston axially movably arranged therein, the piston being pressed by the user to introduce air and released to generate negative pressure.

[0037] Further features, advantages and applicability of the present invention will become apparent from the following description of exemplary embodiments and the drawings. All features described herein and / or shown in the drawings, by themselves and in any combination, constitute the subject matter of the present invention, regardless of how they are assembled in the individual claims or references thereto. Furthermore, in the drawings, the same reference numerals represent identical or similar objects. [Brief explanation of the drawings]

[0038] [Figure 1] FIG. 1 is a cross-sectional view of the filling system. [Figure 2] FIG. 2 shows the ink reservoir with the filling system without the fountain pen installed. [Figure 3a] FIG. 3a shows an ink reservoir together with the filling system in which the fountain pen is placed. [Figure 3b] FIG. 3b is a diagram showing a schematic diagram of a fountain pen configured to utilize the filling system. [Figure 4] FIG. 4 illustrates the process of placing a fountain pen on the filling system. [Figure 5] FIG. 5 illustrates the process of placing a fountain pen on the filling system. [Figure 6] FIG. 6 is a detailed cross-sectional view showing the overflow of the filling system. DETAILED DESCRIPTION OF THE INVENTION

[0039] 1 shows a filling system 2 for a fountain pen 4. The filling system 2 has a pump unit 6 that can be mounted on an ink reservoir 8. The pump unit 6 has a cylinder 10 that has a bottom area 12 and an opening 14 facing away from the bottom area 12.

[0040] A piston 16 is arranged axially movably in the cylinder 10. The piston has, by way of example, a radial projection 18 locally which can slide in a groove 20 in the cylinder 10, thereby preventing the cylinder 16 from rotating.

[0041] A first sealing body 24 is arranged on the underside 22 of the piston 16. It is positively connected to the piston 16. To this end, the first sealing body 24 has a circumferential radial groove 26 into which a circumferential radial projection 28 of the piston 16 extends. The first sealing body 24 has two spaced-apart, circumferentially circumferential annular sealing lips 30 that come into surface contact with the inner wall 32 of the cylinder 10. This forms an air chamber 34 between the bottom section 12 and the underside of the piston 16, and air therein is pressurized by movement of the piston 16.

[0042] 1, the piston 16 is in a neutral position, terminating substantially flush with the opening 14 of the cylinder 10. Between the bottom section 12 and the piston 16 is a compression spring 36, illustratively made as a coil spring, which always urges the piston 16 back to the neutral position.

[0043] An air passage 38 extends from the air chamber 34 through the piston to a first connection 40, which may be in the form of a small tube. A separate ink passage 42 extends from this through the bottom section 12 and the piston 16 to a second connection 44. The second connection is preferably configured concentrically with the first connection 40, the openings of both connections being spaced apart from one another. The opening of the first connection 40 protrudes beyond the opening of the second connection 44, although this may also be reversed.

[0044] The ink passage 42 has a submerged end 46 that protrudes from the piston 16. The submerged end 46 is intended to plunge into the ink container 8, in which the ink volume is located. When the piston 16 is pressed by the user in the direction of the bottom area 12, the volume of the air chamber 34 decreases. To compensate for the air pressure, air flows into the air passage 38 and is guided there to the first connection 40. There, an air line 46 of the fountain pen 4 is provided that is then fluidly connected to the air passage 38, so that air flows therein from the air passage 38.

[0045] The ink tank of the fountain pen 4, not shown here, is connected to the air line 46, which is likewise in fluid connection with the ink line 48. Via this, the remaining ink is guided from the ink tank of the fountain pen 4 to the second connection 44 and thus to the ink channel 42. It then flows into the ink container 8. When the piston 16 is released, a negative pressure is generated in the air channel 38 due to the piston 16 being pushed back to its neutral position, so that ink is sucked into the ink tank by the fluid connection with the ink line 48 and the ink channel 42. The fountain pen 4 can therefore be simply fitted to the filling system 2 and filled by pushing and releasing the piston 16.

[0046] The immersion end 46 is guided in an axially sliding manner by a second sealing body 50 integrated into the bottom section 12. This allows sealing of the air chamber 34 relative to the ink container 8. The immersion end has a larger outer diameter in a first section 52 of the immersion end 46 than in a second section 54 arranged on the side of the immersion end 46 facing the piston 16. This forms a kind of step 56, which allows the immersion end 46 to fit flush against the second sealing body 50 or against an additional stopper 58.

[0047] The cylinder 10 has a step 62 on its outer surface 60 for seating the cylinder 10 flush on the opening edge 64 of the ink container 8. The portion of the cylinder 10 that projects into the ink container 8 has an outer diameter adapted to match the inner diameter of the ink container 8 so that the cylinder 10 seats in the ink container 8 with as little clearance as possible.

[0048] The fountain pen 4 illustratively has two third sealing bodies 66 through which the first connecting portion 40 and the second connecting portion 44 extend when the fountain pen 4 is mated with the new system 2. These sealing bodies may be part of the filling system 2.

[0049] Figure 2 shows the filling system 2 on the ink container 8. Here, a threaded ring 68 is provided for attaching the filling system 2 to the ink container 8, which has a thread 70 for this purpose (see also Figure 1). To facilitate the introduction of the fountain pen 4 into the filling system 2, the filling system has an insertion sleeve 72 that protrudes from the opening 14. Once the fountain pen 4 is fitted, the connection with the connections 40 and 44 can be established.

[0050] In Figure 3a, it can be seen how the process of connecting the filling system 2 and the fountain pen 4 takes place. This is shown in a little more detail in Figures 4 and 5 below, where the fountain pen 4 has both connections 40 and 44 and both third sealing bodies 66 that are not yet connected in the position of Figure 4. In Figure 5, the fountain pen 4 is fitted flush into the filling system 2, whereby the lower edge 74 of the fountain pen 4 abuts the receiving surface 76 of the filling system. The piston 16 can then be pressed down to start the filling process.

[0051] 3b shows a highly schematic view of an ink tank 82 with a first cutout 84 and a second cutout 86, which in this example are located at opposite ends of the ink tank 82. The first cutout 84 is connectable to an air line 88, and the second cutout 86 is connectable to an ink line 90. The air line 88 and the ink line 90 can be joined by a coupling mechanism 92 that can be linked to the first connection 40 and the second connection 44. This connects the air line 88 to the first connection 40, and the ink line 90 to the second connection 44. The drawing should be understood as being schematic. The coupling mechanism 92 can also contemplate a concentric arrangement of both lines 88 and 90.

[0052] Finally, FIG. 6 shows that the immersion end 46 has an overflow area 78. The overflow area is located adjacent to the sealing area 54 in the direction of the piston 16 and is located within the second sealing body 50, so that a gap is open when the piston 16 is in its neutral position. When the piston 16 is operated, the sealing area 54 moves into the second sealing body 50, thereby sealing the air chamber 34. The overflow area 78 has a tapered portion at least in a partial area, so that ink can pass from the air chamber 34 through the bottom area 12 and into the ink container via the overflow area 78. If too much ink is sucked into the ink line 48 from the ink container 8 when filling the fountain pen 4, this ink can enter the air chamber 34 and flow out again from there before the piston 16 has returned to its neutral position.

[0053] It should be pointed out that "comprises" does not exclude other elements or steps, and "a" does not exclude a plurality. It should also be pointed out that an element described with reference to one of the above embodiments can also be applied in combination with another element of another embodiment described above. The reference signs in the claims should not be considered as limitations. [Explanation of symbols]

[0054] 2. Filling System 4 fountain pen 6 Pump Unit 8 Ink container 10 cylinders 12 Bottom area 14 Openings 16 pistons 18 Radial protrusion of piston 20 grooves 22 Bottom side 24 First seal body 26 Radial grooves 28 Circumferential protrusion 30 Radial sealing lip 32 Inner wall 34 Air chamber 36 Compression spring 38 Air passage 40 First connection part 42 Ink passage 44 Second connection 46 Immersed end 48 Ink duct 50 Second seal body 52 First Area 54 Second Area 56 Step part 58 Stopper 60 Exterior 62 Step part 64 Opening edge 66 Third seal body 68 Threaded Ring 70 threads 72 Insertion sleeve 74 Lower Edge 76 Storage Surface 78 Overflow Area 80 Seal Area 82 Ink tank 84 First incision 86 Second incision 88 Air Pipe 90 Ink duct 92 Coupling mechanism

Claims

1. A filling system (2) for a fountain pen (4), a pump unit (6); an air passage (38) connected to a first connection part (40) for connecting the pump unit (6) and the fountain pen (4); an ink passage (42) connected to a second connection part (44) for connection with the fountain pen (4), the ink passage (42) being separated from the air passage (38) and having an immersion end (46) for immersion in ink; The pump unit (6) is configured to introduce a predetermined volume of air into the air passage (38) with an overpressure to flush ink from the fountain pen (4), and subsequently apply a negative pressure to the air passage (38), thereby drawing a predetermined volume of ink from the ink passage (42) into the fountain pen (4).

2. 2. A filling system (2) for a fountain pen (4) according to claim 1, wherein the pump unit (6) is mechanical or electrical.

3. The pump unit (6) includes a cylinder (10) having a bottom area (12) and an opening (14) facing away from the bottom area (12), a piston (16) axially movably disposed within the cylinder (10), and a spring member (36) that drives the piston (16) toward the opening (14); The air passage (38) extends through the piston (16) from an air chamber (34) formed between the piston (16) and the bottom area (12); The ink passage (42) extends through the bottom area (12) and the piston (16); 3. The filling system (2) according to claim 1 or 2, wherein the piston (16) is radially sealed against the cylinder (10), whereby pressing the piston (16) towards the bottom area (12) generates an overpressure acting against the first connection (40), and releasing the piston (16) generates a negative pressure acting against the first connection (40).

4. 4. The filling system (2) of claim 3, wherein the spring member (36) is a compression spring and is disposed between the bottom section (12) and the piston (16).

5. 5. The filling system (2) according to claim 3 or 4, wherein the piston (16) has a first sealing body (24) arranged on the side facing towards the bottom area (12).

6. 6. The filling system (2) according to claim 3, wherein the immersion end (46) is guided so as to slide axially by a second sealing body (50) arranged in the bottom section (12).

7. 7. The filling system (2) of claim 6, wherein a sealing area (80) of the immersed end (46) fits into the second sealing body (50) outside a neutral position of the piston (16), where the piston (16) ends flush with the opening (14), and the immersed end (46) has an overflow area (78) arranged adjacent to the sealing area (80) in the direction of the piston (16), the overflow area having a tapered portion in at least a partial region for conducting ink from the air chamber (34) through the bottom area (12).

8. 8. The filling system (2) according to any one of claims 1 to 7, wherein the first connection part (40) and the second connection part (44) are made concentric to each other.

9. 9. The filling system (2) of claim 8, wherein the first connection portion (40) is disposed within the second connection portion (44) and extends beyond the second connection portion (44).

10. 4. The filling system (2) according to claim 3, wherein the first connection portion (40) and the second connection portion (44) are arranged in an insertion sleeve (72) arranged on a side of the piston (16) facing away from the air chamber (34).

11. 11. The filling system (2) according to any one of claims 1 to 10, wherein the first connection portion (40) and the second connection portion (44) are arranged concentrically with each other.

12. 4. The filling system (2) of claim 3, wherein a first section (52) of the immersed end (46) located on a side of the bottom section (12) facing away from the air chamber (34) has a larger outer diameter than a second section (54) located within the air chamber (34) when the piston (16) is in a neutral position.

13. 4. The filling system (2) according to claim 3, wherein the air passage (38) and the ink passage (42) are arranged in the piston (16) radially offset from one another in at least a partial region.

14. 4. The filling system (2) according to claim 3, wherein the cylinder (10) has a step (62) on its outer surface for placing the cylinder (10) flush on an opening edge (64) of the ink container (8).

15. A writing instrument system comprising: a filling system (2) according to any one of claims 1 to 14; and a fountain pen (4), wherein the fountain pen (4) comprises a coupling mechanism (92) and at least one ink tank (82) having a first incision (84) and a second incision (86), wherein the coupling mechanism (92) is connected to the first incision (84) and the second incision and is connectable to the first connection portion (40) and the second connection portion (44), thereby establishing a fluid connection between the first connection portion (40) and the first incision (84), and between the second connection portion (44) and the second incision (86).

16. A method for filling a fountain pen (4), comprising: a first connection portion (40) of the pump unit is connected to a first incision portion of at least one ink tank in said fountain pen (4); a second connection portion (44) of the pump unit (6) is connected to a second opening portion of at least one of the ink tanks in the fountain pen (4); immersing an immersion end (46) of the ink passage (42) extending to the second connection portion (44) in ink in the ink container; introducing air with an overpressure into said first connection (40) to expel ink in at least one of said ink tanks through said second connection (44) into said ink container; generating a negative pressure at said first connection (40) to draw ink into at least one said ink reservoir via said second connection (44).

17. 17. The method according to claim 16, wherein the introduction of air and the generation of negative pressure are performed by a pump unit (6) having a cylinder (10) and a spring-loaded piston (16) arranged axially movably therein, the piston being pressed by the user to introduce air and released to generate negative pressure.

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