EP0943456A1 - Flexible container for writing tool - Google Patents

Abstract

The reservoir comprises a supple sachet (1) made from at least two layers of material welded at the lengthwise edges and at one end. The other end is closed by a ring (2) and ball stopper (3). The ball is pressed in to the reservoir when fitted in to the writing implement.

Description

The present invention relates to an ink tank intended for use in a writing instrument. We knows several types of ink tanks for writing instruments, especially cartridges ink used in fountain pens. These cartridges usually consist of a cylindrical tank plastic injected and a ball fixed between two spacers that prevent ink from flowing. During use, we put this cartridge in the pen pen, the ball sealing the cartridge is pushed to inside the cartridge thus allowing the ink to flow towards the pen.

The so-called 'pasty' inks, i.e. those normally having a viscosity greater than 8000 cps, are usually contained in a tube in polypropylene fitted with a metal billed tip. If the tube diameter is too large (greater than 2.6 millimeters), or if the viscosity is lower, it is necessary to introduce a layer of substance at high surface tension to prevent ink leakage through the free end of the tube. Once injected, the ink is brought into contact with the ball by centrifugation, the resulting absence of air means that the ink does not leak from the back. If the viscosity decreases, the surface tension is normally no longer sufficient to prevent leakage from the back of the tube. this is valid for very low viscosity inks and for water-based inks. This is also true for all liquids for which a surface tension value of the order of 35 dynes cannot be reached. In that case, a substance of higher viscosity and tension higher surface is necessary to guarantee the correct functioning of writing instruments. We will note however that the development of such substances is complex and expensive. To solve this problem, we have offered different solutions, water-based inks are for example contained in fiber pads or in tanks that require passages complicated and difficult to master to replace the ink used by an equivalent volume of air. this is necessary to guarantee pressure equalization, this which allows the ink to flow from the reservoir to the point. These devices require conduits capillaries (polyester or fiber) to regulate the flow ink between the tank and the tip and avoid this does any untimely reflux (drain back effect). These systems are complicated and expensive to develop and to manufacture. In addition, the ink used being substituted by a corresponding volume of fresh air, there is a early deterioration of ink qualities.

Other applications using low liquids viscosity provide for closed tanks which exhibit an internal overpressure to guarantee the flow of the liquid to across the tip. In this case, the tip is provided with a internal spring which pushes the ball towards the internal part crimping to seal the system. During use, the ball is pressed against the action of the spring, towards its seat and frees up a passage surface around which the ink can escape.

Some glue dispensers and pens correctors use this principle. These devices are complex and expensive to manufacture.

The object of the present invention is to remedy the disadvantages mentioned above by offering a reservoir for writing instrument that balances pressure without having to replace the ink used with air. Thanks to this device, aging and deterioration of the qualities of the ink due to its contact with ambient air. It is also possible to use all kinds of inks without them have specific viscosity characteristics or that it is necessary to add a layer of high surface tension substance, so completely independent of the type of writing system adopted (billed point, roller, felt, fineliner or other).

This goal is achieved by a distinctive device by the characteristics defined in claim 1.

Other advantages emerge from the description and features set out in the claims dependent. The invention will be described with reference to attached drawing which schematically represents example a tank according to the invention.

Figure 1 is a cross-sectional view of a ink tank for writing instrument according to the invention, the latter being closed.

Figure 2 is a view identical to Figure 1, the tank being mounted on the tip of an instrument to write.

Figure 3 illustrates the reservoir of Figures 1 and 2 when empty.

Figure 4 is a side view of a tank according the invention mounted on a ball point.

Figure 5 is a partial sectional view of the ball point illustrated in figure 4.

Figure 6 shows a writing instrument comprising a tank object of the invention and a first form of execution of means to act on said tank, the tank being full.

Figure 7 is a view similar to that shown in Figure 6, the tank being half empty.

Figure 8 illustrates a writing instrument comprising a tank object of the invention and a second embodiment of the means interacting with The reservoir.

Figure 9 illustrates a writing instrument comprising a tank object of the invention and a third embodiment of the means interacting with The reservoir.

Figure 10 illustrates a writing instrument comprising a tank object of the invention and a fourth embodiment of the means interacting with The reservoir.

Figure 11 is a side view of a tank flexible according to the invention mounted on a ball point, the reservoir comprising at the distal end of the tip means for filling.

Figure 12 is a view identical to that illustrated in Figure 11, during the filling operation.

Figure 13 is an exploded view in partial section a writing instrument comprising a reservoir according to the invention and provided with an interchangeable tip.

Referring to Figure 1, the flexible tank is consisting of a deformable bag 1 closed with a ring 2 comprising a ball 3 held in a housing. The sachet 1 can consist of a sheet composed of several layers of different material. For exemple not limiting, the sheet constituting the sachet can include a first layer of PET (terephthalate polyethylene) 12 microns thick, one second aluminum layer about 8 microns thick and a third layer of low density polyethylene (LDPE low density polyetylen) with a thickness of about 60 microns. This type of manufacturing requires welding longitudinal, and a transverse. Welding by ultrasound is perfectly suited to achieve such sachet 1. Note that less complicated leaves can also be used for the realization of the sachet 1. Another method of making sachet 1 consists in obtaining a tube by extruding a composition based on polyester combined with polyethylene. This mode of manufacturing requires only a transverse weld to close the bag. Preferably use a hot contact for this type of manufacturing.

Bags made using one of two methods described above and with the compositions mentioned have the advantage of being both impermeable to ink and lightfast components. The sachet thus obtained is then welded to the ring in plastic 2.

Figure 2 illustrates the tank coupled with a ball point. Tip 4, when coupling, penetrates the ball 3 inside the bag 1 and thus allows ink 5 to supply the tip 4. Figure 3 illustrates the instrument to be written when the bag 1 is practically empty.

Figures 4 and 5 illustrate a variant in which the bag 1 forming a flexible tank is mounted directly (by welding for example) on tip 6 of a writing instrument. The ink flowing towards the tip at ball through a passage 7. This assembly can then be arranged in the rigid body 8 of an instrument to write as shown in figure 6.

In these different forms of execution, the deformation of the bag allows to equalize the pressure without however, replace ink 5 with the air. Thus, the fact of not having a supply of fresh air reduces the aging speed of the ink 5. Thanks to this tank, it is also not necessary to provide a high viscosity mass to hold the ink in the reservoir tube thus formed.

For certain uses of a writing instrument, the ink tank must have a pressure higher than ambient pressure is especially the case when you want to use a writing instrument pointing upwards. The Figures 7 to 10 illustrate a writing instrument having means for mechanical deformation the flexible tank 1. In this way, the flexible tank consisting of bag 1 can be pressurized and allow use under the conditions set out above. This has an advantage over traditional rigid tanks, which must be put under pressure during manufacturing, which requires complex and expensive manufacturing processes. Many solutions are possible to deform the reservoir 1, by way of nonlimiting example, three embodiments different are illustrated in Figure 7 to 10. Figure 7 represents a writing instrument in whose body is arranged a flexible tank 1 according to the invention. A piston 9 sliding in the body 8 of the pen under the action of a spring 10 allows to compress and deform the bag 1 forming a reservoir. The ink thus under pressure is supplied through passage 7 towards the billed point 6. Figure 8 shows the instrument when part of the ink 5 has been used. FIG. 8 illustrates a variant in which the rear end of the instrument body is threaded and can accommodate a plug acting as a piston fitted with a thread. By screwing the latter more or less depending on the use, we put the ink 5 sous pressure by compressing the bag 1. Figure 10 illustrates another variant in which the member making it possible to compress the reservoir 1 consists of a cap 12 cylindrical elastic with annular grooves on its periphery. These gorges delimit areas whose diameter is substantially equal to the internal diameter of the body 8 of the instrument and which form notches. This plug 12 can be forced into the body of the instrument at the touch of a finger end. Other solutions can of course be envisaged to compress longitudinally see radially the bag 1 forming a reservoir. Thanks to this system it is possible to manufacture pens rechargeable correctors, which is not normally the case case, pressurizing the ink in the devices existing being complicated to realize.

It is also possible to increase the pressure during the welding operation of the sheets constituting the sachet 1. This gives a flexible tank having an internal pressure higher than the external pressure.

Figure 11 illustrates a variant of a tank flexible according to the invention mounted on a ball point 6. The bag 1 is welded at its end opposite the tip on the outer surface of a cylindrical ring 13. The ring 13 partially emerges from bag 1 and can accueuillir a removable closure member, shown in drawing in the form of a plug 14.

In this particular form of execution, and as shown in figure 12, it is possible to fill the tank 1 using a container 15 having a spout suitable for insertion into ring 13. The stopper 14 can be screwed onto the emerging part of the ring 13 which will then be fitted with a thread. Other ways to fixing the plug 14 on the ring 13 may well heard be considered.

In FIG. 13, the flexible tank 1 provided with its plug 14 is mounted on an intermediate element 16. This element 16 is shaped so that it can be introduced into the body of a writing instrument 18, the central part of element 16 bearing in position assembled against the annular surface of the body 18. The tip 17 of the instrument has a recess whose dimensions correspond to those of the lateral part of item 16.

This embodiment allows the replacement of the tip 17 in case of wear for example.

Claims (12)

Tank for writing instrument, characterized by made up of a flexible deformable bag (1) open at one end. Tank according to claim 1, characterized by the sachet (1) consists of a sheet having at least two layers of different material and that it has a longitudinal weld and a weld transverse. Tank according to claim 1, characterized by fact that it consists of a tube obtained for example by extrusion and that it has a transverse weld closing one of its ends. Tank according to claim 1, characterized by causes it to have at its closed end a member removable shutter consisting of a cylindrical ring 13 emerging from the bag 1 on which is fixed a plug 14. Tank according to one of the preceding claims, characterized by the fact that it is fixed at its end open on an annular ring (2) presenting in sound centers a housing in which a removable ball (3) is maintained. Tank according to one of claims 1 to 4, characterized by the fact that it is united to its open end of a ball point. Tank according to one of claims 1 to 4, characterized by the fact that it is united to its open end of a connecting element (16) shaped so as to be able to be introduced into the body (18) of a writing instrument and able to accommodate a point (17) at a free end. Writing instrument consisting of a hollow body (8) provided at one of its ends with a point (6), characterized by the fact that it comprises, arranged in the body (8) a tank (1) according to one of claims 1 to 4. Writing instrument according to claim 8, characterized by the fact that it includes means allowing to deform the flexible tank (1). Writing instrument according to claim 9, characterized by the fact that said means making it possible to deform the tank (1) have a piston (9) sliding longitudinally in the body (8) of the instrument under the action of a spring (10). Writing instrument according to claim 9, characterized by the fact that the means for deform the flexible tank (1) consist of a cylindrical plug (11) provided with a thread. Writing instrument according to claim 9, characterized by the fact that the means for deform the tank (1) consist of a cap cylindrical (12) elastic having notches.

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