EP0064527B1 - Apparatus for writing, drawing, painting or similar with interchangeable cartridge - Google Patents

Description

The invention relates to writing, drawing, painting or similar devices with a cartridge that can be fixed in the shaft, exchangeable, provided at the front with an application tip protruding from the front end of the shaft, for a medium to be applied with the device, which can be inserted into the shaft from the front and can be fixed in it in the use position by means of a snap-lock connection acting directly between the inside of the shaft and the outer wall of the cartridge and in the locked position by means of guide elements against rotation against the shaft. “Medium” means both liquids and pastes, i.e. Means commonly used for writing, drawing, painting, marking, etc. Since the composition of such media is irrelevant, this will not be discussed in more detail.

A large number of current devices, in particular for writing and drawing, are equipped with exchangeable cartridges so that when the medium contained in the cartridge is used up, only the cartridge, but not the entire device, has to be replaced. The shaft usually consists of several, essentially coaxial parts that can be fixed to each other with a screw connection, for example. To replace the cartridge, a part must be removed, for example unscrewed, after which the cartridge can be removed and replaced with a new one. In such a procedure, on the one hand, the replacement of the cartridge is relatively cumbersome, especially when the two shaft parts are fixed to one another by means of a screw connection. On the other hand, the production of several parts requires a greater manufacturing and device outlay than would be required if the shaft of the device could consist of one piece. Finally, in the known writing instruments with a multi-part shaft, the setting of corresponding tolerances also presents difficulties, which is why the cartridge is usually held in the correct position in the shaft by means of a spring element, but this increases the manufacturing outlay.

There are also large quantities of disposable devices on the market in which the cartridge cannot be replaced. Such devices can only be produced in a very cheap version, which is not always satisfactory.

Finally, from US-A-3 601 494 a device of the type mentioned is known in which only a single snap connection from an undercut at the front end of the shaft or a corresponding projection on the cartridge is provided for fixing the cartridge to the shaft . To release the snap-in connection, the cartridge is pressed inwards with respect to the shaft in the area of the snap-in connection. For this purpose, the cartridge has a grip zone projecting over the front end of the shaft in the use position.

This grip zone projecting forward over the shaft, on the one hand, gives the known device a peculiar appearance. On the other hand, its handling is impaired because the front edge of the shaft usually lies in an area that is gripped when the device is used. However, this is made unnecessarily difficult in the known device. If the cartridge protrudes relatively far beyond the front edge of the shaft, there is a risk that the device cannot be guided properly because the elastically designed cartridge can give in unintentionally. Another serious shortcoming of the known device can be seen in the fact that the guidance of the cartridge in the shaft under certain circumstances enables its rotation relative to the shaft. To guide the cartridge is only a one-sided flattening of the cartridge, which should also allow an attack with the finger. This flattening interacts with a projection on the lower edge of the shaft.

For this reason, the cartridge is only secured against rotation relative to the shaft in a narrowly limited area and, moreover, does not function reliably because of the flexible design of the cartridge in the flattened area. Due to the special design of the rotation lock, it is difficult in the known device to insert the cartridge into the correct position in the shaft. However, if it is not inserted exactly in the correct orientation, there is a risk that it will become jammed in the area of the front end of the shaft and then the shaft or the cartridge may be damaged when an attempt is made to detach the shaft and cartridge. A precisely predetermined position of the application tip of the cartridge relative to the shaft cannot be achieved in the known device, which is, however, also irrelevant because the application tip has an approximately circular cross-section.

The invention is based on the object of developing a generic writing instrument in such a way that the cartridge is properly guided relative to the shaft of the writing instrument and it is ensured that even when the cartridge is changed, the new cartridge is always in a precisely predetermined rotational position relative to the shaft , so that cartridges with a specially shaped tip and shafts with a special cross-section can be used, as is the case with text markers, for example, in which the tip is spatula-shaped and the shaft is flattened, in order to ensure that they are suitable for application the leading edge of the application tip, which is used for marking fluid, is always in a predetermined position relative to the hand of the user. At the same time, the handling of the device when changing cartridges should be made easier.

To achieve this object, it is proposed according to the invention that the shaft in the area its front end has at least one longitudinal groove in which a bar provided on the outside of the wall of the cartridge can be inserted, and that the bar is designed as a pressure element for pressing in the wall of the cartridge by a sufficient amount to release the snap-in connection.

In the device according to the invention, the anti-rotation of the cartridge relative to the shaft is thus accomplished by at least one longitudinal groove at the front end of the shaft and a bar which engages in the position of use on the outside of the wall of the cartridge. This type of anti-rotation device can be manufactured with great accuracy, which is why it can be used not only with round devices but also with devices that have a cartridge or a shaft with a cross-section that deviates from the circular shape and causes a coarse anti-rotation device . Even with such devices, it is only through an embodiment in the manner explained above that it is ensured that the cartridge and thus the tip of the application assume a precisely predetermined position with respect to the shaft. Another advantage of the device according to the invention can be seen in the fact that it is comparatively easy to insert the bar or bars on the outside of the cartridge into the slot or the slots at the front end of the shaft, the cartridge being tilted relative to the shaft the longitudinal extension of the bar and slot is excluded. Finally, the solution of the snap-in connection does not pose any difficulties, because it is only necessary to push the strips and thus the cartridge wall accordingly far.

A particularly simple shaft design is obtained when the longitudinal groove is formed by a slot. This training also has the advantage that the bar on the cartridge is visible on the side of the writing instrument. You can therefore color the bar accordingly and use it to mark the contents of the cartridge.

It is further provided that the shaft has two longitudinal grooves opposite and the cartridge has two corresponding strips in order to achieve a symmetrical locking.

Finally, it is within the scope of the invention that the shaft has an opening at its rear end encompassing the rear end of the cartridge. Such a design also permits a perfect axial alignment of the cartridge in the shaft, even with a comparatively large clearance between the cartridge and the shaft. In addition, such an opening offers the possibility of providing the rear end of the cartridge with a marking which characterizes the contents and which is then also visible from the rear end of the shaft when the cartridge is inserted.

A preferred exemplary embodiment of a marking device according to the invention is explained in more detail below with reference to the drawing.

• Fig. 1 teilweise im Schnitt das Markiergerät,
• Fig. 2 im Schnitt den in Fig. 1 mit A gekennzeichneten Bereich der Rastverbindung zwischen Patrone und Schaft bei eingerasteter Patrone und
• Fig. 3 einen Schnitt entsprechend Fig. 2 während der Auswechslung der Patrone, d.h. bei gelöster Rastverbindung.

Show it:

• 1 partially in section the marking device,
• Fig. 2 in section the area marked with A in Fig. 1 of the snap connection between the cartridge and the shaft with the cartridge and
• Fig. 3 shows a section corresponding to Fig. 2 during the replacement of the cartridge, ie with the detent connection released.

The marking device shown in Fig. 1 has a cartridge 1 with a relatively large volume, which almost completely fills the interior 2 of the shaft 3. In this way, a comparatively good guidance of the cartridge 1 in the interior of the shaft is already achieved without special aids. The application tip 4 can be covered by means of a cover cap (not shown in the drawing), in which connection it should be pointed out that the shaft per se, as can be seen from FIG. 3, extends to the front edge 5 which appears in FIG , to which a possibly attached cap pushes.

The shaft 3 is open at its front edge 5 over the entire cross section and is closed by the appropriately shaped front end of the cartridge 1 when it is in the latching position (FIGS. 1, 2).

A snap-in connection, which can be seen particularly clearly from FIGS. 2 and 3, serves to fix the cartridge 1 in the shaft 3.

To form the locking connection, the shaft 3 has an undercut 6 on the inside, which forms a shoulder 7. With this undercut, a projection 8 on the outer wall of the cartridge 1 cooperates in the latched position, which also has a shoulder 9. For locking purposes, the shoulders 7 of the undercut 6 and 9 of the projection 8 lie against one another in the manner shown in FIG. 2.

FIGS. 2 and 3 clearly show that the projection 8 - or, in the exemplary embodiment shown, the two projections 8 - are directly molded onto the wall 10 of the cartridge 1. Furthermore, the cartridge 1 consists of an elastically deformable material. In this way, by slightly compressing the cartridge 1, it is possible to release the latching connection, i.e. to move the projections 8 out of the locking position shown in FIG. 2 into the position of FIG. 3, where the cartridge 1 can then be removed from the shaft 3.

Near its front end, the shaft 3 has longitudinal slots 11; in the exemplary embodiment shown there are two opposite longitudinal slots into which corresponding, radially projecting strips 12 of the cartridge 1 can be inserted from the front edge 5. These strips 12 serve on the one hand as guide elements for the cartridge 1 with respect to the shaft 3, whereby they can, for example, prevent the cartridge 1 from rotating relative to the shaft 3 when the shaft 3 and cartridge 1 are round. On the other hand, the strips 12 can be used as pressure elements, for which purpose they are so wide or so high that in the region of the troughs 13 sufficient pressure can be exerted to release the snap connection between the cartridge 1 and the shaft 3, ie the wall 10 of the cartridge 1 can be bent correspondingly far inwards.

In the exemplary embodiment shown, the height of the strips 12 is selected in accordance with the thickness of the wall of the shaft 3. In this case, the strips 12 must have a sufficient width. If only comparatively narrow strips 12 are provided, their thickness must be chosen somewhat larger, so that they protrude at least to a small extent over the outside of the shaft 3 in order to enable the strips 12 to move sufficiently inwards and thus to release the latching connection .

It can be seen from FIG. 1 that the cartridge 1 largely fills the interior of the shaft 3. However, there is still a certain space between the wall of the shaft 3 and the outside of the cartridge 1, which is necessary in order to be able to easily insert the cartridge 1 into the shaft 3. This would mean that the cartridge might move slightly sideways. In order to reliably prevent this, the rear end of the cartridge 1 has an extension 14 which engages in a suitable opening 15 on the end face 16 of the shaft 3 as soon as the cartridge 1 is in the latched position.

The presence of the strips 12 or the attachment 14 on the cartridge 1 makes it possible to make corresponding markings with respect to the contents of the cartridge 1, which are visible even when the device is closed. For this purpose, only the attachment 14 and the strips 12 have to be marked accordingly when the cartridge 1 is manufactured.

Of course, the principle of the invention can not only be used in writing instruments with comparatively thick cartridges, although it is particularly favorable there because of the possible movement of the cartridge wall and its use in connection with the latching. It would of course also be possible to provide a corresponding latching connection between the cartridge and the shaft even in the case of differently designed devices, in which case special latching elements would then have to be provided on the cartridge.

Claims (4)

1. An implement for writing, drawing, painting or similar with an exchangeable cartridge, which can be fixed in the barrel provided at the front with an applicator tip projecting from the front end of the barrel for a medium to be applied with the implement, which can be inserted into the barrel from the front and be fixed therein in the operating position by means of a catch engagement joint acting directly between the internal side of the barrel and the external wall of the cartridge and which is in its rest position secured against rotation in relation to the barrel by means of guide elements, characterised in that barrel (3) has, in the zone of its front end (5) at least one longitudinal groove (11) into which there may be inserted a fillet (12) provided on the outside of wall (10) of cartridge (1) and in that fillet (12) is formed as a thrust element for pressing in wall (10) of cartridge (1) to an extent that is adequate for releasing the catch engagement joint.

2. An implement according to Claim 1, characterised in that the longitudinal groove is formed by a slot (11 ).

3. An implement according to Claim 1 or 2, characterised in that the barrel (3) has two longitudinal grooves (11) on opposite sides and cartridge (1 ) two corresponding fillets (12).

4. An implement according to one of the preceding Claims, characterised in that barrel 3 has, at its rear end (16) an opening (15) surrounding the rear end (14) of cartridge (1 ).

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