WO2025215118A1 - Filter cartridge, system and filter device - Google Patents

Abstract

The invention relates to a filter cartridge (2) for an inlet funnel (3) of a filter device (1), wherein the filter cartridge (2) has a filter chamber (2.1) in which a filter medium (2.2) for filtering a liquid is arranged, wherein the filter device (1) has at least one inlet opening (2.3) through which the liquid to be filtered enters the filter chamber (2.1), and wherein the filter cartridge (2) has, in the region of its base (2.5), at least one outlet opening (2.4) through which the filtered liquid leaves the filter chamber (2.1), wherein the base (2.5) of the filter cartridge (2.1) is flat or has a funnel-shaped taper (2.6). The invention further relates to a novel valve opener (4) for opening a valve (3.4) of an inlet funnel (3) for a filter device (1), and to a filter device (1).

Description

DESCRIPTION

Title

Filter cartridge, system and filter device

State of the art

The present invention relates to a filter cartridge for an inlet funnel of a filter device, wherein the filter cartridge has a filter chamber in which a filter medium for filtering a liquid is arranged, wherein the filter device has at least one inlet opening through which the liquid to be filtered enters the filter chamber, and wherein the filter cartridge has at least one outlet opening in the region of its base through which the filtered liquid leaves the filter chamber.

Such filter cartridges are known in principle from the state of the art and are typically used to optimize water quality. The filter cartridges contain a filter medium in the form of granules for the chemical and/or mechanical removal or reduction of organic and inorganic contaminants.

For example, WO 2005/118481 A1 discloses a generic filter cartridge that can be inserted into the inlet funnel of a filter jug for filtering water. For this purpose, the inlet funnel has a receiving chamber that forms a seat for the filter cartridge. The bottom of the receiving chamber has a hollow body with an opening directed toward the filter cartridge. When the filter cartridge is inserted into the receiving chamber, the hollow body is received in a recess formed in the bottom of the filter cartridge, and the mandrel engages the opening of the hollow body. The channel formed by the wall of the hollow body and the mandrel is then intended to function as a throttling device.

A similar liquid treatment system is disclosed in DE 20 2016 008 866 U1, in which a movable valve body is arranged in the hollow body at the bottom of the inlet funnel. This valve body is moved from a closed position to an open position by means of the mandrel arranged in the recess at the bottom of the filter cartridge, so that the filtered water can flow from the inlet funnel into the reservoir of the filter jug. The mandrel is designed as a valve actuation device. which engages in a spiral contour of the valve body in order to convert a linear movement into a rotary movement that opens the valve.

The publication WO 2022/207 155 A1 discloses a valve lifter designed to grip the valve body by means of a gripping edge formed as a ring strip and to lift it into its open position due to an elastic deformation of parts of the valve lifter, as illustrated, for example, in Figure 7A. A disadvantage of this arrangement is that the valve lifter is always arranged in a recess of the filter cartridge, which is formed on the underside of the housing of the filter cartridge.

A disadvantage of the prior art arrangements is that the filtered water must always follow a complex flow path with 180-degree turns to reach the inside of the filter cartridge through the inlet funnel valve and thus into the filter jug. This results in an unnecessarily high flow resistance, which means that the outer filter areas of the filter cartridge are either not flowing through or flow through only slowly.

In addition, dead spaces form in the filter cartridge, particularly in the narrow areas between the cartridge wall and the indentation on the long sides of the cartridge, where no significant fluid flow occurs. These areas, on the one hand, lack filter function, and on the other, unwanted fluid reservoirs form. This compromises hygiene by encouraging germ growth, and also impairs handling comfort, as the residual water in the dead spaces drips out of the filter cartridge when removing used ones.

Disclosure of the invention

It is an object of the present invention to provide a filter cartridge that does not have the disadvantages mentioned above in connection with the prior art and that ensures improved and, in particular, as complete a drainage of residual liquid as possible before or at least immediately upon removal of the filter cartridge from the inlet funnel, in order to increase hygiene, ease of use, and filter performance. Furthermore, the filter cartridge should be simpler, more resource-efficient due to material savings, and thus more cost-effective to manufacture.

The above object is achieved by a filter cartridge according to claim 1. The subject matter of the present invention relates to a filter cartridge for an inlet funnel of a filter device, wherein the filter cartridge has a filter chamber in which a filter medium for filtering a liquid is arranged, wherein the filter device has at least one inlet opening through which the liquid to be filtered enters the filter chamber, and wherein the filter cartridge has at least one outlet opening in the region of its base through which the filtered liquid leaves the filter chamber, wherein the base of the filter cartridge is flat or has a funnel-shaped taper.

In contrast to the prior art, the base of the filter cartridge is flat or funnel-shaped, so that the filter cartridge in particular has no indentation at its base containing the outlet opening. This advantageously prevents dead spaces in which standing water forms, thus preventing the formation of germs. In addition, the cartridge empties more effectively before removal from the inlet funnel, thus increasing ease of use. The cartridge with a base in the form of a funnel-shaped taper is particularly advantageous in this case, with the outlet opening preferably being arranged in the center of the funnel-shaped taper. In this way, all areas of the filter are flowed through as evenly as possible in the direction of the outlet opening and the formation of dead spaces is efficiently prevented. The filter medium comprises in particular a granulate for the chemical and/or mechanical removal or reduction of organic or inorganic contaminants in water. To ensure that the filter cartridge can always exert a sufficient cleaning effect through its filter medium, the filter cartridge must be changed at regular intervals. The reduction of dead spaces in the filter cartridge according to the invention makes changing the filter cartridge more convenient, since the risk of contamination from water dripping out of the filter cartridge when removing the used filter cartridge from the inlet funnel is reduced. The filter cartridge preferably has a single or a plurality of inlet openings. The filter cartridge also preferably has a single or a plurality of outlet openings. In addition, the filter cartridge preferably has a clamping surface by means of which the filter cartridge is clamped in the inlet funnel.

Advantageous embodiments and further developments of the invention can be found in the dependent claims and the description with reference to the drawings. According to a preferred embodiment of the present invention, the filter cartridge has a main flow direction that extends essentially from the inlet opening along a longitudinal axis of the filter cartridge to the outlet opening, with the funnel-shaped taper being formed along the main flow direction. The base of the filter cartridge thus preferably tapers in the flow direction up to the mouth of the outlet opening, so that the filtered liquid collects in the region of the outlet opening or can escape from the filter cartridge through the outlet opening.

According to a preferred embodiment of the present invention, the funnel-shaped taper is formed in a transverse plane perpendicular to the longitudinal axis in the center of the base of the filter cartridge. It is conceivable that the funnel-shaped taper tapers towards the outlet opening formed in the center of the base, wherein the outlet opening corresponds or overlaps in the longitudinal direction with the position of the valve in the inlet funnel. Preferably, the filter cartridge is intended for insertion into an inlet funnel designed in this way, which has an access opening, a base provided with a valve, and a receiving space for the filter cartridge arranged between the access opening and the valve, wherein the funnel-shaped taper faces the valve and/or points towards the valve. The filter cartridge is particularly dimensioned such that the base of the filter cartridge inserted into the inlet funnel is arranged along the longitudinal axis between the filter chamber and the valve, and the base of the filter cartridge and the valve do not overlap in a transverse plane perpendicular to the longitudinal axis. In other words, the valve is always arranged below the base of the filter cartridge. This ensures that no base area is located at the level of the valve and therefore no liquid would have to flow back from this lower area of the cartridge, i.e. against the main flow direction (upwards), in order to leave the inlet funnel towards the reservoir of the filter jug. This reduces flow resistance and can be determined solely by the geometry and number of outlet openings in the cartridge.

According to a preferred embodiment of the present invention, the filter cartridge comprises a valve opener which is arranged behind the base of the filter cartridge along the main flow direction and is arranged along the longitudinal axis in particular always between the base of the filter cartridge and the base of the inlet funnel and/or wherein the valve opener and the base of the filter cartridge in particular do not overlap in a transverse plane perpendicular to the longitudinal axis. Advantageously, the valve opener is thus always located below the filter cartridge and also below the The use of a valve opener in the filter cartridge according to the invention thus does not have the disadvantage of necessarily requiring an indentation at the bottom of the filter cartridge, as is the case with the prior art. Despite the valve opener, a filter cartridge with a flat or funnel-shaped bottom is thus possible, thus achieving the aforementioned advantages.

According to a preferred embodiment of the present invention, it is provided that the valve opener has a receiving opening into which a valve body of the valve protrudes at least partially when the valve opener and in particular the filter cartridge is arranged in the receiving space, wherein an edge of the receiving opening comprises a valve lifter which enters into a frictional and/or positive connection with the valve body when the valve body protrudes into the receiving opening, and wherein the valve opener and/or the filter cartridge has a restoring means which exerts a restoring force on the valve lifter to transfer the valve body into the open position after the frictional and/or positive connection has been established.

It is conceivable that the edge of the receiving opening clamps the valve body laterally and holds it in place solely by frictional engagement or that the edge contains engagement means in the form of fingers which engage laterally in structures on the valve body, such as spiral grooves, in order to grip the valve body in a form-fitting manner.

According to a preferred embodiment of the present invention, the return means for the filter cartridge comprises an elastically deformable return means, preferably in the form of a spring element or an elastomer, for example a rubber-elastic compression element, which is supported in particular on the bottom of the inlet funnel or on a pipe section of the valve to generate the return force. It is conceivable that the return means is elastically pretensioned when the filter cartridge is manually pushed into the receiving space, and that the pretension is released upon release, leading to the valve body being transferred into the open position. It is also conceivable that the valve opener has a funnel contact surface via which the valve opener is securely supported on the bottom of the inlet funnel. Preferably, the funnel contact surface is coated with an elastomer, which is compressed when the filter cartridge is pushed in and increases in volume again upon release, whereby the valve body, gripped by means of the edge of the receiving opening, is transferred into its open position opposite to the assembly direction. Instead of the elastomer, a circumferential bending or spiral spring between the funnel contact surface and the bottom of the inlet funnel is also conceivable. An expansion edge, which is attached to a curve of the pipe section, slips off, is conceivable. Furthermore, it is conceivable that the return means are alternatively bent by the upper edge of a pipe section, as known from WO 2022/207 155 A1. Furthermore, it is conceivable that the filter cartridge has the return means. This is provided in particular in an embodiment in which the filter cartridge and the valve opener are formed in one piece or are connected to one another. The return means is deformed when the filter cartridge is inserted into its seat on the inlet funnel and the filter cartridge is then moved back (in particular a small amount) counter to the assembly direction when the return means is reformed, in particular as soon as the manual force of the user for pressing the filter cartridge in the assembly direction subsides, whereby the valve lifter is also moved accordingly and the valve opens. In this variant, the return means is arranged in particular (latterly) between the filter cartridge and a wall of the inlet funnel, for example in the form of an elastically deformable lip.

In a further variant of the invention, the restoring means comprises a swelling element that swells upon contact with water, thereby increasing its volume. It is conceivable that the swelling of the swelling element generates the restoring force for moving the valve body into the open position, with the swelling element being supported, in particular, on the bottom of the inlet funnel or on a pipe section of the valve to generate the restoring force.

A further subject of the present invention is a system comprising the filter cartridge according to the invention and a valve opener, wherein the valve opener and the filter cartridge can be inserted along an assembly direction together or separately into a receiving space of the inlet funnel, wherein the receiving space has a base in which a valve is arranged that can be actuated between a closed position and an open position, wherein the valve opener has a funnel contact surface that is in contact with the inlet funnel when the valve opener is arranged in the receiving space, wherein the valve opener has a filter contact surface that is in contact with the filter cartridge when the valve opener and the filter cartridge are arranged in the receiving space, wherein the valve opener has a receiving opening into which a valve body of the valve at least partially protrudes when the valve opener is arranged in the receiving space, wherein an edge of the receiving opening comprises a valve lifter that enters into a frictional and/or positive connection with the valve body when the valve body protrudes into the receiving opening, and wherein the valve opener and/or the Filter cartridge has a return means which exerts a return force on the valve lifter to transfer the valve body into the Open position after the friction and/or form-fitting connection has been established.

The valve lifter is advantageously arranged below the filter cartridge, so that the system also achieves the advantages described above. The valve lifter can be firmly connected to the filter cartridge, so that the filter cartridge and valve lifter are inserted into the receiving space of the inlet funnel as a single part. Alternatively, the valve lifter and the filter cartridge can also be designed separately, in which case the valve lifter is inserted into the receiving space first and then the filter cartridge. It is conceivable that during a subsequent cartridge change, the valve lifter is also replaced or remains in the inlet funnel and interacts with the new filter cartridge in the manner described.

According to a preferred embodiment of the present invention, the valve opener is designed such that the valve lifter is arranged along the assembly direction between the filter contact surface and the funnel contact surface. Preferably, the valve lifter rests on the funnel contact surface upon insertion into the receiving space and is thus correctly positioned so that the valve body is received by the receiving opening upon insertion of the filter cartridge. In particular, this prevents the valve opener from jamming or tilting, which could then damage the valve upon insertion of the filter cartridge.

According to a preferred embodiment of the present invention, it is provided that the valve opener is arranged in the assembly direction between the filter cartridge insertable into the inlet funnel and the bottom of the inlet funnel, preferably between the bottom of the filter cartridge and the bottom of the inlet funnel.

According to a preferred embodiment of the present invention, it is provided that the return means is formed on or on the funnel contact surface and in particular comprises an elastically deformable return means, preferably in the form of a spring element or an elastomer.

According to a preferred embodiment of the present invention, it is provided that the return means comprises an expansion edge surrounding the valve, which rests on a curve of a pipe section of the valve projecting from the bottom of the inlet funnel into the receiving space. According to a preferred embodiment of the present invention, it is provided that the filter contact surface is firmly connected, in particular glued, to the bottom of the filter cartridge, or the valve opener and the filter cartridge are two separate, unconnected parts.

A further object of the present invention is a filter device comprising a filter jug, an inlet funnel and the system according to the invention.

Further details, features, and advantages of the invention will become apparent from the drawings and the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the essential inventive concept.

Short description of the drawings

Figure 1 shows a schematic sectional view of a filter cartridge and a system according to an exemplary first embodiment of the present invention.

Figure 2 shows a schematic sectional view of a filter cartridge and a system according to an exemplary second embodiment of the present invention.

Figure 3 shows a schematic sectional view of a filter cartridge and a system according to an exemplary third embodiment of the present invention.

Figure 4 shows a schematic detailed view of a valve opener of a filter cartridge and a system according to an exemplary fourth embodiment of the present invention.

Figure 5 shows a schematic detailed view of a valve opener of a filter cartridge and a system according to an exemplary fifth embodiment of the present invention. Figure 6 shows a schematic detailed view of a valve opener of a filter cartridge and a system according to an exemplary sixth embodiment of the present invention.

Figure 7 shows a schematic detailed view of a valve opener of a filter cartridge and a system according to an exemplary seventh embodiment of the present invention.

Figure 8 shows a schematic detailed view of a valve opener of a filter cartridge and a system according to an exemplary eighth embodiment of the present invention.

Embodiments of the invention

In the various figures, identical parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

Figure 1 illustrates a schematic sectional view of a filter cartridge 2 and a system according to an exemplary first embodiment of the present invention.

The present example illustrates a filter device 1 comprising a filter jug 5 for serving filtered water. The filter jug 5 is provided with a spout, a handle, and a lid, for example.

An inlet funnel 3 is inserted into the filter jug 5. The inlet funnel 3 has an access opening 3.1 through which unfiltered water can be poured into the inlet funnel 3. Furthermore, the inlet funnel 3 has an outlet 3.8 in its base 3.3 at its lower end, through which the water flows from the inlet funnel 3 into the reservoir of the filter jug 5. Between the outlet 3.8 and the access opening 3.1, a receiving space 3.2 is provided, into which a filter cartridge 2 can be inserted.

In the area of the outlet 3.8, the inlet funnel 3 has a valve 3.4, which comprises a pipe section 3.6, which opens into the outlet 3.8, and a valve body 3.5. The valve body 3.5 is movable within the pipe section 3.6 between a closed position and an open position. In the closed position, no water can pass through the valve 3.4 from the inlet funnel 3 towards the reservoir, while in the In the open position, water can flow from the valve 3.4 towards the reservoir. The closed position is, in particular, a position in which the valve body 3.5 rests on the outlet 3.8 due to its gravity, thus closing it. In the open position, the valve body 3.5 is slightly raised relative to the outlet 3.8, thereby opening it. Figure 1 schematically illustrates the valve 3.4 in the closed position. The pipe section 3.6 protrudes from the base 3.3 of the inlet funnel 3 towards the filter cartridge 2, counter to the assembly direction 100, and thereby accommodates the valve body 3.5.

In the present example, the filter cartridge 2 is inserted into the receiving space 3 according to the exemplary first embodiment of the invention. The filter cartridge 2 is inserted by a user through the access opening 3.1 along an assembly direction 100 into the receiving space 3 of the inlet funnel 3. The assembly direction 100 extends essentially parallel to a longitudinal axis 102 of the filter cartridge 2.

The filter cartridge 2 has at least one inlet opening 2.3 on its upper side, which in the present case is designed purely by way of example in the form of several parallel inlet slots. On its underside, the filter cartridge has at least one outlet opening 2.4, which in the present case is designed purely by way of example in the form of several openings in the base 2.5 of the filter cartridge 2. Extending along the longitudinal axis 102 between the inlet openings 2.3 and the outlet openings 2.4 is a filter chamber 2.1, which is at least partially filled with a filter medium 2.2. The filter medium 2.2 comprises in particular a granulate for the chemical and/or mechanical removal or reduction of organic or inorganic impurities in the water which flows through the filter cartridge 2 along a main flow direction 101 from the inlet openings 2.3 to the outlet openings 2.4. For special areas of application, it is preferably provided to strengthen the granulate in such a way that additives such as minerals are added to the water flowing through, which contribute to the well-being of the user who consumes the water.

The filter cartridge 2 is a wearing part, i.e., a filter cartridge 2 in use must be replaced by a user with a new filter cartridge 2 after a certain period of time or after a certain number of usage cycles. In this case, the used filter cartridge 2 is removed from the receiving space 3.2 opposite to the mounting direction 100, and a new filter cartridge 2 is inserted along the mounting direction 100. When using the filter cartridge 2, two requirements in particular should be met: Firstly, when removing the previously used filter cartridge 2, as little (old) water as possible should flow out of the filter cartridge 2 so that the area surrounding the filter device 1 is not contaminated and operating comfort is not impaired. Secondly, to achieve a high filtering effect, the entire bed of filter medium should be flowed through as comprehensively and homogeneously as possible. Both objectives can be achieved with the filter cartridge 2 according to the invention by designing the base 2.5 of the filter cartridge 2 to be flat or essentially flat. In the present example, the base 2.5 of the filter cartridge 2 extends perpendicular to the longitudinal axis 102. This has the advantage that - unlike in the prior art - no dead spaces are created by a complicated shape of the base area, which could then serve as a reservoir for old water or impair the homogeneous flow through the filter medium 2.2.

The flat design of the base 2.5 of the filter cartridge 2 is made possible by the fact that the base 2.5 ends along the longitudinal axis 102 above the valve 3.4 and its pipe section 3.6. This means that the valve 3.4 is always arranged between the base 2.5 of the filter cartridge 2 and the base 3.3 of the inlet funnel 3 in the main flow direction 101 or assembly direction 100. In a transverse plane 103 perpendicular to the longitudinal axis 102, neither the base 2.5 of the filter cartridge 2 and the base 3.3 of the inlet funnel 3, nor the base 2.5 of the filter cartridge 2 and the valve 3.4 overlap, not even partially. Only in this way can a completely flat base 2.5 be realized.

In order for the filter cartridge 2 to exert its filtering effect, the valve 3.4 must be moved from the closed position to the open position. For this purpose, the system has a valve opener 4, which is preferably placed on the pipe section 3.6 and surrounds it circumferentially. The valve opener 4 is arranged along the longitudinal axis 102 or along the main flow or assembly direction 101, 100 between the base 2.5 of the filter cartridge 2 and the base 3.3 of the inlet funnel 3. Here, too, the valve opener 4 overlaps neither the base 2.5 of the filter cartridge 2 nor the base 3.3 of the inlet funnel 3 in the transverse plane 103.

The valve opener 4 is also arranged in the receiving space 3.2 and has a central receiving opening 4.1 through which the valve body 3.5 protrudes when the valve opener 4 is arranged in the receiving space 3.2. The diameter of the receiving opening 4.1 is so small that the valve opener 4 can only be opened under the influence of force. is slipped over the valve body 3.5, causing the receiving opening 4.1 to expand, particularly elastically. This causes the edge of the receiving opening 4.1 to subsequently form a frictional connection with the surface of the valve body 3.5. The edge of the receiving opening 4.1 thus forms a valve lifter 4.2, since lifting the edge via the frictional connection with the valve body 3.5 leads to a lifting of the valve body 3.5. The valve 3.4 is thus moved into the open position.

In order to ensure that sufficient force can be exerted on the valve lifter 4.2 in the assembly direction 100 so that it slips over the valve body 3.5, the valve opener 4 has a filter contact surface 4.4 on its upper side, via which the valve opener 4 is in contact with the filter cartridge 2. When the filter cartridge 2 is pressed by a user into its seat in the receiving space 3.2, the valve opener 4 is also pressed towards the bottom 3.3 of the inlet funnel 3 via the filter contact surface 4.4, causing the valve body 3.5 to slide into the receiving opening 4.1.

On a side facing the bottom 3.3 of the inlet funnel 3, the valve opener 4 has a funnel contact surface 4.3. This funnel contact surface 4.3 is in direct or indirect contact with the bottom 3.3 of the inlet funnel 3 and ensures that - as soon as the pressure towards the bottom 3.3 of the inlet funnel 3 is released by the user - a counterforce is exerted on the valve lifter 4.2 counter to the installation direction 100. For this purpose, the valve opener 4 has an elastically deformable return means 4.5. In the present example, the return means 4.5 comprises an elastomer which, under the pressure of the user, is initially elastically compressed in the installation direction 100 and - after the pressure is released by the user - then increases in volume again counter to the installation direction 100, in particular until it has (almost) reached its original volume again due to its vertical expansion. During this return movement, the valve lifter 4.2 is already in frictional engagement with the valve body 3.5 and carries it along in the opposite direction of the assembly direction 100. The valve 3.4 is thus opened. It is particularly important that the valve lifter 4.2 is always positioned in the longitudinal direction 102 between the funnel contact surface 4.3 and the filter contact surface 4.4 in the valve opener 4.

In an alternative variant, the restoring means 4.5 comprises a swelling element which swells upon contact with water and thereby increases its volume. It is conceivable that this swelling element comes into contact with the water to be filtered and swells upon first use of the filter device 1 with the new valve opener 4. The swelling of the swelling element then generates the restoring force for transferring the valve body 3.5 into the open position, wherein the swelling element moves to generate the restoring force in particular at the bottom 3.3 of the inlet funnel 3 during swelling. The material of the swelling element comprises, for example, a so-called superabsorbent. Such a superabsorbent comprises, in particular, cross-linked polymers that can absorb up to a thousand times their own weight in water, transforming it into a solid gel. The superabsorbent experiences an increase in volume due to the absorbed water, which causes the vertical movement of the valve body 3.5. A cross-linked and partially neutralized polyacrylic acid is behind this absorption effect. An osmotic (negative) pressure builds up in the cross-linked polymer particle due to the sodium ions bound there. As a result, surrounding water is sucked into the interior. The water absorption continues until the elastic restoring forces of the extended polymer network compensate for the osmotic forces. The degree of cross-linking essentially controls the capacity and rate of water absorption.

The valve opener 4 can either be firmly connected, i.e. in particular rigidly, to the filter cartridge 2 or be designed as a separate part from the filter cartridge 2. If the valve opener 4 and cartridge 2 are firmly connected to one another, then there is in particular an adhesive connection between the filter contact surface 4.4 and the base 2.5 of the filter cartridge 2 or, preferably, the housing of the filter cartridge 2 and the valve opener 4 are formed integrally with one another. The valve opener 4 is then advantageously automatically inserted into the receiving space 3.2 when a filter cartridge 2 is inserted into the receiving space 3.2 by the user.

In the separate design, the user must first insert the valve opener 4 into the receiving space 3.2 along the assembly direction 100 before subsequently inserting the filter cartridge 2 into the receiving space 3.2. Only by inserting the filter cartridge 2 is sufficient pressure exerted on the valve opener 4 so that the receiving opening 4.1 slides over the valve body 3.5, and the valve body 3.5 is thus frictionally received in the receiving opening 4.1.

The valve opener 3.4 extends in the circumferential direction around the longitudinal axis 102 around the pipe section 3.6 of the valve 3.4 and, after insertion, has at least partial indirect or direct contact with the bottom 3.3 of the inlet funnel 3 with its funnel contact surface 4.3. This has the advantage that the valve opener 3.4, after insertion into the receiving space 3.2, is held in its (correct) position by the pipe section 3.6 until the filter cartridge 2 is also inserted into the receiving space 3.2. In particular, the risk of the valve opener 3.4 slipping during the time in which no filter cartridge 2 fixes the valve opener 2. This ensures that the pressure generated when inserting the filter cartridge 2 does not lead to damage to the valve 3.4 or the valve opener 4, but only brings about the desired frictional connection between the valve lifter 4.2 and the valve body 3.6. This advantage is achieved in particular by the fact that, in the valve opener 4 in question, the valve lifter 4.2 is always arranged between the funnel contact surface 4.3 and the filter contact surface 4.4 in the longitudinal direction 102 or assembly direction 100.

Figure 2 illustrates a schematic sectional view of a filter cartridge 2 and a system according to an exemplary second embodiment of the present invention. The second embodiment is essentially similar to the first embodiment explained with reference to Figure 1, so that almost all of the above statements also apply to this example. However, there are two differences between the first and second embodiments:

The first difference is that the base 2.5 of the filter cartridge 2 according to the second embodiment is not flat, but has a funnel-shaped taper. The funnel-shaped taper extends in the assembly direction 100 toward the valve 3.4. It is thus formed in the center of the base 2.5 of the filter cartridge 2, with one or more outlet openings 2.4 of the filter cartridge 2 optionally also being formed in this center or at an outermost tip of the taper pointing toward the valve 3.4. This has the advantage that the residual emptying of the filter cartridge 2 upon its removal from the inlet funnel 3 is even more efficient. The flow through the filter medium 2.2 during use of the filter cartridge 2 is also even more homogeneous.

The second difference is that the return means 4.5 is not in the form of a compressible elastomer, but comprises a spiral spring that at least partially surrounds the pipe section 3.6. The spiral spring protrudes obliquely in the longitudinal direction 102 from the funnel contact surface 4.3 towards the bottom 3.3 of the inlet funnel 3. When pressure is exerted on the valve opener 4 via the filter cartridge 2, the spiral spring bends until it runs almost parallel to the transverse plane 103. When the pressure decreases, the spiral spring returns to its original shape and displaces the valve lifter 4.2 counter to the assembly direction 100, thereby opening the valve 3.4. As an alternative to the spiral spring, a spiral spring surrounding the pipe section 3.6 could also be arranged at this point. Figure 3 illustrates a schematic sectional view of a filter cartridge 2 and a system according to an exemplary third embodiment of the present invention. The third embodiment is essentially similar to the first embodiment explained with reference to Figure 1, so that almost all of the above statements also apply to this example.

The third embodiment differs from the first embodiment only in that the return means 4.5 is not in the form of the elastomer but as a circumferential expansion edge on the valve opener 4

The expansion edge is formed in the area of the funnel contact surface 4.3 and circumferentially delimits a circular opening of the valve opener 4, which is arranged above the pipe section 3.6 of the valve 3.4 when the valve opener 4 is arranged in the receiving space 3.2, so that the pipe section 3.6 is received in the circular opening. The pipe section 3.6 protrudes from the bottom 3.3 of the inlet funnel 3 in the direction of the filter cartridge 2, counter to the assembly direction 100, and thereby accommodates the valve body 3.5. A curve 3.7 is formed in the transition area between the pipe section 3.6 and the bottom 3.3 of the inlet funnel 3. The curve 3.7 causes the maximum diameter of the pipe section 3.7 to increase in the assembly direction 100.

When the valve opener 4 is moved toward the bottom 3.3 of the inlet funnel 3 due to the pressure of the filter cartridge 2, the expansion edge slides over the curve 3.7, elastically increasing the diameter of the expansion edge. As soon as the pressure decreases, the expansion edge contracts again, causing the valve opener to slide upwards in the opposite direction to the mounting direction 100, thereby moving the valve 3.4 into its open position.

Figure 4 shows a schematic detailed view of a valve opener 4 of a filter cartridge 2 and a system according to an exemplary fourth embodiment of the present invention. The fourth embodiment is essentially similar to the first embodiment explained with reference to Figure 1, so that almost all of the above statements also apply to this example.

However, in the fourth embodiment, the valve opener 4 is designed as disclosed in the document WO 2022/207 155 A1, which is why the disclosure content of the document WO 2022/207 155 A1, in particular with regard to the figures 5A to 5E disclosed therein, is hereby incorporated by reference. The valve opener 4 again has a filter contact surface 4.4 and a receiving opening 4.1. In contrast to the other embodiments, however, the valve opener 4 has a funnel contact surface 4.3, which interacts with the end of the tube section 3.6 facing the filter cartridge 2 and in particular with an inner bead at this end of the tube section 3.6, and not with the bottom 3.3 of the inlet funnel 3. This results in the funnel contact surface 4.3 being arranged between the filter contact surface 4.4 and the receiving opening 4.1 in the longitudinal direction 102. The edge of the receiving opening 4.1 here also forms the valve lifter 4.2, which is connected to the filter contact surface 4.4 via return means 4.5 in the form of radial connecting webs. The funnel contact surfaces 4.3 are formed centrally on the connecting webs.

When pressure is applied to the filter contact surface 4.4 in the installation direction 100 during insertion of the filter cartridge 2, a lever effect is exerted on the radial connecting webs. The connecting webs are supported by the funnel contact surfaces 4.3 and thus deform in such a way that the diameter of the receiving opening 4.1 is reduced and the valve body 3.5 moves into its open position opposite to the installation direction 100.

Here, too, the valve opener 4 can be firmly connected to the base 2.5 of the filter cartridge 2 via its filter contact surface 4.4, in particular glued, or formed as a separate part from the filter cartridge 2. Compared to the other embodiments, however, there is the disadvantage that when the valve opener 4 is inserted into the receiving space 3.2, the valve opener 4 cannot assume a stable, fixed position, but can easily slip if the filter device 1 is tilted. When the filter cartridge 2 is then inserted, there is a risk that the valve opener 4 has previously left its ideal position centrally on the pipe section 3.6 and the pressure leads to damage to the valve opener 4 or the valve 3.4. In this fourth embodiment, a fixed connection between the flat or funnel-shaped tapered base 2.5 of the filter cartridge 2 and the filter contact surface 4.4 of the valve opener 2 is considerably more advantageous.

Figure 5 shows a schematic detailed view of a valve opener 4 of a filter cartridge 2 and a system according to an exemplary fifth embodiment of the present invention. The fifth embodiment is essentially similar to the first embodiment explained with reference to Figure 1, so that almost all of the above statements also apply to this example. In contrast to the first embodiment, in the fifth embodiment the filter cartridge 2 and the valve opener 4 are firmly connected to one another; they preferably have a common outer structure and are thus connected to one another in one piece. The filter cartridge 2 again has a flat base 2.5, which extends parallel to the transverse plane 103 and perpendicular to the assembly direction 100. The valve opener 4 is formed below the base 2.5 in the assembly direction 100, wherein the outlet openings are optionally formed in the flat base 2.5 of the filter cartridge 2 in the region of the valve opener 4. The outlet opening 2.4 is designed in particular in the form of a perforation in the base 2.5 of the filter cartridge 2. The valve opener 4 has the valve lifter 4.2, which extends conically downwards in the assembly direction 100 and opens into the receiving opening 4.1. In this embodiment, the edge of the receiving opening 4.1 also forms a gripping edge which engages around the valve body 3.5 as soon as the filter cartridge 4 is inserted into the inlet funnel 3.

In contrast to the first embodiment, the return means 2.7 is not formed on the valve opener 4, but on the filter cartridge 2. The return means 2.7 is designed in the form of a circumferential, elastically deformable lip arranged between the filter cartridge 2 and the wall 3.9 of the inlet funnel 3. The lip also serves as a sealing lip between the inlet funnel 3 and the filter cartridge 2. Optionally, outlet openings 2.4 are also formed laterally of the valve opener 4 in the form of perforations in the base 2.5 of the filter cartridge 2.

The return means 2.7 is deformed when the filter cartridge 2 is manually inserted into its seat on the inlet funnel 3. As soon as the pressure exerted manually by the user to push the filter cartridge 2 into the inlet funnel 3 along the assembly direction 100 subsides, the return means 2.7 attempts to return to its original shape and thereby at least partially recovers. The filter cartridge 2 is thereby moved back, at least a small distance, in the opposite direction to the assembly direction 100. As a result, the valve lifter 4 is also moved accordingly, and the valve body 3.5, gripped by the valve lifter 4.2, is moved from the closed position to its open position.

Figure 6 shows a schematic detailed view of a valve opener 4 of a filter cartridge 2 and a system according to an exemplary sixth embodiment of the present invention. The sixth embodiment is essentially similar to the fifth embodiment explained with reference to Figure 5, so that almost all of the above statements also apply to this example. In contrast to the fifth embodiment, however, the return means 2.7 is not arranged in the area of the filter cartridge 2. This has only a circumferential sealing lip at the point between the filter cartridge 2 and the wall of the inlet funnel 3.

Instead, the return means 2.7 is formed at the lower end of the valve lifter 4, i.e., at the funnel contact surface 4.3. The return means 2.7 is thus located between the upper edge of the tube section 3.6 of the valve 3.4 and the valve lifter 4. The return means 2.7 is designed here as a swelling element (particularly made of superabsorbent material), which increases its volume upon contact with water. Due to this increase in volume, the valve lifter 4 is then displaced counter to the mounting direction 100, thereby moving the valve 3.4 from the closed position to its open position.

Figure 7 shows a schematic detailed view of a valve opener 4 of a filter cartridge 2 and a system according to an exemplary seventh embodiment of the present invention. The seventh embodiment is essentially similar to the fifth embodiment explained with reference to Figure 5, so that almost all of the above statements also apply to this example.

In contrast to the fifth embodiment, the return means 2.7 of the filter cartridge 2 is arranged somewhat lower in the assembly direction 100, so that there is sufficient space in the upper area of the filter cartridge 2 for an additional return means 2.8. The additional return means 2.8 is designed, in particular, analogous to the return means 2.7, as a circumferential sealing lip. Advantageously, the two return means 2.7 and 2.8 result in a greater return force, so that the opening of the valve 3.4 is carried out more reliably.

Figure 8 shows a schematic detailed view of a valve opener 4 of a filter cartridge 2 and a system according to an exemplary eighth embodiment of the present invention. The eighth embodiment is a combination of the seventh embodiment illustrated in Figure 7 with the sixth embodiment illustrated in Figure 6.

The system thus comprises a filter cartridge 2 with a return means 2.7 and a further return means 2.8, both of which are supported on the wall 3.9 of the inlet funnel 3. In addition, the valve opener 4 also has the return means 4.2 in the form of a swelling element (in particular a superabsorbent), which increases its volume upon contact with water. List of reference symbols

1 filter device

2 filter cartridges

3 inlet funnels

4 valve openers

5 filter jug

2 filter cartridges

2.1 Filter chamber

2.2 Filter medium

2.3 Inlet opening

2.4 Outlet opening

2.5 Bottom of the filter cartridge

2.6 Funnel-shaped taper

2.7 Restoring agents

2.8 Additional restoring agent

3 inlet funnels

3.1 Access opening

3.2 Recording room

3.3 Bottom of the inlet funnel

3.4 Valve

3.5 Valve body

3.6 Pipe section of the valve

3.7 Rounding of the pipe section

3.8 Outlet

3.9 Wall of the inlet funnel

4 valve openers

4.1 Receiving opening

4.2 Valve lifter

4.3 Funnel contact surface

4.4 Filter contact surface

4.5 Restoring agents

100 Mounting direction

101 Main flow direction

102 Longitudinal axis

103 Transverse plane

Claims

PATENT CLAIMS 1. Filter cartridge (2) for an inlet funnel (3) of a filter device (1), wherein the filter cartridge (2) has a filter chamber (2.1) in which a filter medium (2.2) for filtering a liquid is arranged, wherein the filter device (1) has at least one inlet opening (2.3) through which the liquid to be filtered enters the filter chamber (2.1), and wherein the filter cartridge (2) has at least one outlet opening (2.4) in the region of its base (2.5) through which the filtered liquid leaves the filter chamber (2.1), characterized in that the base (2.5) of the filter cartridge (2.1) is flat or has a funnel-shaped taper (2.6). 2. Filter cartridge (2) according to claim 1, wherein the filter cartridge (2) has a main flow direction (101) which extends substantially from the inlet opening (2.3) extends along a longitudinal axis (102) of the filter cartridge (2) to the outlet opening (2.4), wherein the funnel-shaped taper (2.6) is formed along the main flow direction (101). 3. Filter cartridge (2) according to one of the preceding claims, wherein the funnel-shaped taper (2,6) is formed in a transverse plane (103) perpendicular to the longitudinal axis (102) in the center of the base (2.5) of the filter cartridge (2). 4. Filter cartridge (2) according to one of the preceding claims, wherein the filter cartridge (2) is provided for insertion into an inlet funnel (3) designed in such a way that it has an access opening (3.1), a bottom provided with a valve (3.4) (3.3) and a receiving space (3.2) for the filter cartridge (2) arranged between the access opening (3.1) and the valve (3.4), wherein the funnel-shaped taper (2.6) faces the valve (3.4) and/or points towards the valve (3.4). 5. Filter cartridge (2) according to claim 4, wherein the filter cartridge (2) is dimensioned such that the bottom (2.5) of the filter cartridge (2) inserted into the inlet funnel (3) is arranged along the longitudinal axis (102) between the filter chamber (2.1) and the valve (3.4) and the bottom (2.5) of the filter cartridge (2) and the valve (3.4) in particular do not overlap in a transverse plane (103) perpendicular to the longitudinal axis (102). 6. Filter cartridge (2) according to one of the preceding claims, wherein the filter cartridge (2) has a valve opener (4) which is arranged along the main flow direction (101) is arranged behind the bottom (2.5) of the filter cartridge (2) and is arranged along the longitudinal axis (102) in particular always between the bottom (2.5) of the filter cartridge (2) and the bottom (2.5) of the inlet funnel (3) and/or wherein the valve opener (4) and the bottom (2.5) of the filter cartridge (2) are arranged in a direction perpendicular to the longitudinal axis (102) vertical transverse plane (103) in particular do not overlap. 7. Filter cartridge (2) according to claim 6, wherein the valve opener (4) has a receiving opening (4.1) into which a valve body (3.5) of the valve (3.4) protrudes at least partially when the valve opener (4) and in particular the filter cartridge (2) is arranged in the receiving space (3.2), wherein an edge of the receiving opening (4.1) comprises a valve lifter (4.2) which enters into a frictional and/or positive connection with the valve body (3.5) when the valve body (3.5) protrudes into the receiving opening (4.1), and wherein the valve opener (4) and/or the filter cartridge (2) has a restoring means (2.7, 2.8, 4.5) which exerts a restoring force on the valve lifter (4.2) to transfer the valve body (3.5) into the open position after the frictional and/or positive connection has been established. 8. Filter cartridge (2) according to claim 7, wherein the restoring means (2.7, 2.8, 4.5) comprises an elastically deformable restoring means, preferably in the form of a spring element or an elastomer, which is supported in particular on the bottom (3.3) of the inlet funnel (3) or on a pipe section (3.6) of the valve (3.4) to generate the restoring force. 9. Filter cartridge (2) according to claim 7, wherein the restoring means (2.7, 2.8, 4.5) comprises a swelling element which increases its volume upon contact with water. 10. Filter cartridge (2) according to one of claims 8 or 9, wherein the valve lifter (4.2) is arranged along the mounting direction (100) between the bottom (2.5) of the filter cartridge (2) and the return means (2.7, 2.8, 4.5). 11. System comprising a filter cartridge (2) according to one of the preceding claims and a valve opener (2), wherein the valve opener (2) and the filter cartridge (2) can be inserted along an assembly direction (100) together or separately into a receiving space (3.2) of the inlet funnel (3), wherein the receiving space (3.2) has a bottom (2.5) in which a valve (3.4) which can be actuated between a closed position and an open position is arranged, wherein the valve opener (4) has a funnel contact surface (4.3) which is in contact with the inlet funnel (3) when the valve opener (4) is arranged in the receiving space (3.2), wherein the valve opener (4) has a filter contact surface (4.4) which is in contact with the filter cartridge (2) when the valve opener (4) and the filter cartridge (2) are arranged in the receiving space (3.2), wherein the valve opener (4) has a receiving opening (4.1) into which a valve body (3.5) of the valve (3.4) protrudes at least partially when the valve opener (4) is arranged in the receiving space (3.2), wherein an edge of the receiving opening (4.1) comprises a valve lifter (4.2) which enters into a frictional and/or positive connection with the valve body (3.5) when the valve body (3.5) protrudes into the receiving opening (4.1), and wherein the valve opener (4) and/or the filter cartridge (2) has a restoring means (2.7, 2.8, 4.5) which exerts a restoring force on the valve lifter (4.2) to transfer the valve body (3.5) into the open position after the frictional and/or positive connection has been established. 12. System according to claim 11, wherein the valve opener (4) is designed such that the valve lifter (4.2) is arranged along the mounting direction (100) between the filter contact surface (4.4) and the funnel contact surface (4.3). 13. System according to claim 12, wherein the valve opener (4) is arranged in the assembly direction (100) between the filter cartridge (2) insertable into the inlet funnel (3) and the bottom (3.3) of the inlet funnel (3), preferably between the bottom (2.5) of the filter cartridge (2) and the bottom (3.3) of the inlet funnel (3). 14. System according to one of claims 11 to 13, wherein the return means (2.7, 2.8, 4.5) is formed on or on the funnel contact surface (4.3) and in particular comprises an elastically deformable return means (2.7, 2.8, 4.5), preferably in the form of a spring element or an elastomer. 15. System according to one of claims 11 to 14, wherein the return means (2.7, 2.8, 4.5) comprises an expansion edge surrounding the valve (3.4) which rests on a curve (3.7) of a pipe section (3.6) of the valve (3.4) projecting from the bottom (3.3) of the inlet funnel (3) into the receiving space (3.2). 16. System according to one of claims 11 to 15, wherein the filter contact surface (4.4) is firmly connected, in particular glued, to the bottom (2.5) of the filter cartridge (2), or the valve opener (4) and the filter cartridge (2) are two separate, unconnected parts. 17. Filter device (1) comprising a filter jug (5), an inlet funnel (3) and a system according to one of claims 11 to 16.