A cartridge for a flexible package and a drive means for emptying the cartridge

Abstract

 A cartridge (2) for a flexible package (1) consists substantially of a housing (3) and a piston (5) arranged displaceably along an axis (A) within the housing. The piston comprises projections (11) which extend outwardly of the piston and through slits (10) in a body portion (6) of the housing (3) of the cartridge (2). The piston (5) may be displaced along the axis (A) of the cartridge (2) by action of force on the projections (11) which extend outwardly of the cartridge (2). The projections may be engaged with external drive means. The external drive means (21) comprise screw means (22) which are engageable with the projections and which are used to displace the piston. Upon displacement of the piston (5), the content within the package (1) is compressed and dispensed through the dispensing opening (4) of the cartridge (2).

Description

[0001] The invention relates to a cartridge for a flexible package and to a drive means for emptying a cartridge according to the preamble of the independent patent claims.

[0002] The use of flexible packages for packing pasty liquids is well known. German utility model 9207385, for example, discloses a sausage like, flexible package for printing inks and a device for emptying such packages. While this is a very economic way for packaging liquids such as printing inks, there are some difficulties for emptying these packages. The German utility model 9207385 discloses a caulking gun for holding and emptying such packages. The major disadvantage of such a device is that, once the package is placed in the emptying device, the package must be completely emptied before another package can be inserted. If there are a number of different liquids to be used, an emptying device for each type of liquid (e.g. for each colour of ink) is necessary. Further, as packages must remain in the emptying device, the material in the dispensing opening may deteriorate or harden.

[0003] It is an object of the present invention to overcome the drawbacks of the prior art, especially to provide a cartridge for a flexible container and a drive means for emptying such a cartridge which allow easy exchange of packages with different liquids, which may be manufactured and filled in a simple and economic way and which allow easy handling.

[0004] According to the present invention, these objects are resolved with a cartridge and a drive means according to the features of the characterizing portion of the independent patent claims.

[0005] The cartridge for a flexible package containing a pasty liquid, such as, for example, a printing ink, comprises a housing with a dispensing opening and a piston arranged displaceably along an axis within the housing. A flexible package may be placed within the housing. The piston is used for applying an axial force on the package. In response to the force, the liquid is dispensed through the dispensing opening. According to the present invention, the housing comprises at least one slit in its side wall, running approximately parallel to the axis of the housing. The piston is provided with at least one projection which extends outwardly from the piston. Through each slit arranged on the housing of the cartridge, there is one projection extending outwardly from the housing. By applying a force on the projection, the piston may be displaced and the content of the package may be dispensed. The projection(s) extending out of the housing of the cartridge are engageable with external drive means for moving the piston along the axis of the housing.

[0006] In a preferred embodiment, the cartridge comprises two slits. The slits are preferably arranged at a distance from each other corresponding to an angle of about 180°.

[0007] It is further preferred that the housing is substantially cylindrical or prismatic in form. Such a design is particularly simple for "sausage-like" cylindrical or prismatic packages.

[0008] The piston preferably has an outer diameter which corresponds to the inner diameter of the housing or which is slightly larger than the inner diameter of the housing and which may be slightly flexible or deformable. In this way, a friction force is created between the piston and the housing. Due to this friction force, the piston remains in an intermediate position within the housing when the package is partially emptied.

[0009] The simple and inexpensive design allows the use of a separate cartridge for each package in use. When the package containing a specific liquid, e.g. an ink, is to be used, the corresponding cartridge may be placed in a drive means for creating a movement of the piston. Therefore, due to the projections extending outwardly of the housing, only one drive means is needed for any number of cartridges each containing a package with a specific type of liquid.

[0010] Preferably, the cylindrical housing comprises a tubular body which is closed at one end by the displaceable piston and which is closed at the other end by a cover which comprises the dispensing opening. The package is compressed between the cover and the piston when the piston is displaced. The slots are provided in the tubular body and the piston is moveable along the tubular body.

[0011] As the projections for displacing the piston extend out of the cartridge, the drive means for emptying the cartridge can be of a particularly simple design. The drive means according to the present invention comprises at least one screw means which is engageable with the projections of the piston for displacing the piston. Screw threads are selected in such a way (sufficiently deep and spaced) that engagement with the projections is possible. With such type of design, the two projections may be put simply in the helix of the screws without any firm engagement between the screw means and the projections. As soon as the screws are rotating, an axial pressure on the projections is created and the piston is displaced. The cartridge may be replaced without the need to loosen any fixing or connection between the cartridge and the drive means. An advantage of screw threads consists in that the projections of the piston may be engaged with the screw threads immediately, at any location on the screws, independent of the position of the piston, e.g. even if the cartridge is partially emptied and the piston is in an intermediate position, the cartridge can be placed into the drive means without changing the position or orientation of the drive means, i.e. screws.

[0012] The screws may be provided with a screw thread having a groove formed therein which is engageable with a protrusion arranged on the projection of the piston.

[0013] Other means or designs for avoiding separation of the screw means on the piston in a plane perpendicular to the axis of the screw means are conceivable.

[0014] Preferably, the screw means are driven by an electric motor operated by batteries. This permits a drive means which is easily removable and which can be used at any location within a fabrication facility.

[0015] In a further preferred embodiment, the screw means are coupled to the motor by a reduction gear. This allows the use of conventional electric motors having relatively high speeds. Due to the reduction gear, the content of the package can be dispensed sufficiently slowly.

[0016] If the motor is battery-driven, the drive means can be formed as a hand-held drive means.

[0017] In a further preferred embodiment, the cartridge is held in the drive means in a space delimited by two screws. The screws are arranged distant from each other and form a space for the cartridge. The drive means further comprises holder means for holding the cartridge in a precisely defined position.

[0018] Of course, the screws may also be provided with additional elements displaceable along their axis, such as a nut.

[0019] In some cases, it may be easier to engage the projections of the piston with a nut on the screws rather than with the screw threads. Instead of a nut, an element comprising threads which are engageable with both screws and further comprising specifically designed engaging surfaces for the projection of the piston is conceivable.

[0020] The invention will be more clearly understood with reference to a preferred embodiment and to the following drawings which show:

Figure 1

A schematic view of a cartridge according to the present invention

Figure 2

A detailed view of the piston according the present invention

Figure 3

A perspective view of the cartridge and a drive means according to the present invention

Figure 4

A schematic view of a sausage like package

Figure 5

A cross-section through a cartridge according to the invention comprising a sausage like package

Figure 6

An enlarged view of the screw threads in engaging contact with the projections of the piston

[0021] Figure 1 shows a cartridge 2 consisting substantially of a housing 3 with a body 6, a cover 7 with a dispensing opening 4 and a piston 5 which is displaceable along an axis A of the cartridge 2.

[0022] The piston 5 (which is not shown in Figure 1) comprises projections 11 which extend outwardly from the piston 5 through slits 10 which are formed in the body 6 of the cartridge 2. The piston 5 can be moved parallel the axis A along the slits 10.

[0023] Figure 2 shows piston 5 in more detail. The piston 5 comprises an upper surface 14 for applying a force on a package 1 (Figure 5) which is contained in the cartridge 2. The piston 5 is further provided with an outer edge 15 having an outer diameter which is equal to or slightly larger than the inner diameter of the cartridge 2. Due to the friction created between the piston 5, especially its outer edge 15 and the inner surface of the body 6 of the cartridge 2, the piston may be held within the body 6 and remains at a specific position without additional external force.

[0024] The projections 11 can be attached to the piston. A certain flexibility of the projections in a direction parallel to the axis of the cartridge allows easier insertion of the projection 11 into the screw threads. Resilience can be achieved by a separate projection and by spring means, attaching the projection 11 to the piston 5.

[0025] Both the body 6 of the cartridge 2 and the piston are formed substantially cylindrical. It is, however, conceivable to use cartridges and pistons of other shapes, especially of any polygonal cross-section.

[0026] If the piston 5 is displaced along the axis A, a package 1 (not shown in Figure 1) can be compressed between the upper surface 14 of the piston and the cover 7 of the cartridge. The content which is contained within package 1 is therefore dispensed through the dispensing opening 4. The piston 5 can be displaced along the axis A through action of force on the projections 11 which extend outwardly of the body 6.

[0027] Figure 3 shows a drive means 21 for holding the cartridge 2 and for displacing the projections 11 in the slits 10 of the body 6.

[0028] The drive means comprises a holder means for holding the cartridge 2 in a defined position. The holder means consist of a holder 24 and a recess 23 which is formed at the bottom of the drive means.

[0029] Two screws 22 are arranged distant with respect to each other and form a space S for the cartridge 2. The projections 11 are in engaging contact with the helix of the screws 22. The screws 22 are rotating in counter sense and displace the piston 5 along the axis A. The screws 22 are driven by a motor 25 which is not explicitly shown and are connected to the motor by a reduction gear which is not explicitly shown. The drive means 21 is formed as a hand-held drive means and can be used at any location in a production facility if needed. A force of up to 180kg per screw may be exerted, which can create a pressure of up to 6 bar in a package containing ink.

[0030] Figure 4 shows schematically a flexible, cylindrical package 1 which can be used in a cartridge and a drive means according to the present invention. The package comprises a thin wall 20 in which a pasty liquid is enclosed. The package 1 is closed at two ends 8 by clips. An elongated end 9 on one side may be used to insert the end 8 in a dispensing opening 4 of a cartridge 2. The wall 20 is made from a flexible plastic sheet, such as PE or PET or laminates of aluminum and appropriate plastic material, at a thickness of about 10-150µm. Depending on the context, other material, such as plastic having barrier properties or multi-layer foils or aluminium foils may be used.

[0031] For emptying a full package 1, the package 1 is placed into the cartridge 2. The piston 5 is displaced to the lower end of the housing, the package 1 is placed with one end 8 on the upper surface 14 of the piston, and the elongated end 9 of the package 1 is passed through the dispensing opening 4 of the cover 7. The cover is subsequently put on the housing 3 of the cartridge 2 containing the package 1. For each type of liquid, a corresponding package may be placed in a separate cartridge 2 and may remain therein. Upon use, the cartridge is placed in the drive means 21. As there are no firm engaging contacts between the drive means 21 and the cartridge 2, exchange of different cartridges 2 is very easy. The cartridge 2 may simply be put in the recess 23 of the drive means 21 and the projections 11 of the piston 5 are brought in contact with the helix of the screws 22.

[0032] If another type of liquid is to be used, the cartridge 2 may be removed from the drive means 21 and a new cartridge 2 may be placed therein. As the piston 5 is in a frictional contact with the inner surface of the body 6, the piston remains in its intermediate position and the package 1 remains partially compressed. The cartridge 2 may therefore be stored complete with the package 1 for future use.

[0033] Figure 5 shows a cross-section through a cartridge 2 comprising a cylindrical package 1. The package is compressed between the upper surface 14 of a piston 15 displaceably arranged within the housing 3 especially in slits 10 of the body portion 6 of the housing. Two projections 11 extend outwardly through the slits 10. Each of the projections 11 is engageable with a screw 22. Action of these screws 22 displaces the piston 5 along the axis A and compresses the package 1 between the upper surface 14 of the piston and the cover 7 closing the housing 3 of the cartridge 2 at the other end. Upon compression of the package 1, the content of the package is displaced through an elongated end 9 of the package which is passed through a dispensing opening 4 of the cover 7.

[0034] Figure 6 shows schematically a section of the thread of the screw 22 in engagement with the projection 11 of the piston 5. The threads are provided with a groove 30 which receives a protrusion 31 arranged on the lower surface of the projection 11. Engagement between the groove 30 and the protrusion 31 avoids separation between the screws 22 and the piston even if high loads are created.

[0035] The present invention is particularly advantageous in combination with pasty liquids such as printing inks. It is, however, understood that any type of pasty liquids, especially glues, sealing material or food, can be packed in this type of package and can be used in cartridges according to the present invention.

[0036] While it is preferred that the cartridge and the packages are of a cylindrical shape, any form of a package is conceivable. A major issue of the present invention is the projections of the piston which extend outwardly of the cartridge 2 and which are engageable with external drive means without creating a firm contact.

Claims

1. A cartridge (2) for a flexible package (1) containing a pasty liquid, the cartridge (2) comprising a housing (3) with a body (6) and with a dispensing opening (4) and a piston (5) arranged displaceably along an axis (A) within said housing (3) for applying a force on the package (1) and for emptying the pasty liquid through the dispensing opening (4),
characterized in that the housing (3) has at least one slit (10) formed in the body portion (6) and in that the piston (5) is provided with at least one projection (11) extending outwardly from the piston (5), wherein the projection (11) extends through the slit (10), the projection being engageable with drive means (21) for moving the piston (5) along the axis (A) of the housing (3).

2. A cartridge (2) according to claim 1, characterized in that two slits (10) are formed in the housing (3) of the cartridge (2).

3. A cartridge according to claim 2, characterized in that the slits (10) are arranged displaced at an angle (A) of 180° with respect to each other.

4. A cartridge according to one of the claims 1 to 3, characterized in that the housing (3) is substantially cylindrical or prismatic to receive a substantially cylindrical or prismatic package.

5. A cartridge according to one of the claims 1 to 4, characterized in that the housing (3) comprises a tubular body (6) closed at one end by the piston (5) and closed at the other end by a cover (7) comprising the dispensing opening (4), said slits (10) being provided in the tubular body (6).

6. A drive means (21) for emptying a cartridge (2) according to one of the claims 1 to 5, characterized in that the drive means (21) comprises at least one screw means (22) engageable with projections (11) of a piston (5) for displacing the piston (5).

7. A drive means (21) according to claim 6, characterized in that the screw means (22) have threads with a width and depth appropriate for engagement with the projections (11).

8. A drive means (21) according to claim 6 or 7, characterized in that the screw means (22) are driven by an electric battery-operated motor.

9. A drive means (21) according to claim 8, characterized in that the screw means (22) is coupled to the motor by a reduction gear.

10. A drive means (21) according to one of the claims 6 to 9, characterized in that the drive means is a hand-held drive means.

11. A drive means (21) according to one of the claims 6 to 10, characterized in that the screws are arranged distant to each other defining an intermediate space (S) for a cartridge (2), the drive means comprising holder means (23, 24) for holding said cartridge (2).

12. A drive means according to one of the claims 6 to 10, characterized in that the screws (22) are provided with threads having a means (30) for engaging means (31) on the projections (11) of the piston (5) for compensating any force directed away from the axis of the screw (22) in a plane perpendicular to the axis of the screws (22)

13. A drive means according to claim 12, wherein the means on the screw threads are formed as a groove (30) and in that the means on the projection (11) are formed as a protrusion (31)

Drawing