RU2814034C1 - Water tank with filter cartridge - Google Patents

Abstract

FIELD: household appliances.

SUBSTANCE: water tank for a household appliance with a connection for a filter cartridge. The water tank has a ring-shaped sealing surface at the bottom for sealing the filter cartridge. The sealing surface surrounds a through hole in the bottom of the tank designed to allow water to flow from the filter cartridge through the bottom wall of the tank into the appliance. The sealing surface of the tank has a variable radius along its circumference relative to the central axis, so that the sealing surface of the tank has radial concavities and radial convexities, while the convexities and concavities have a rounded shape and are made to periodically oscillate along the circumference.

EFFECT: effective fixation of the filter cartridge in the tank.

21 cl, 18 dwg

Description

The invention relates to a water tank with a filter cartridge according to the restrictive part of claim 1 of the formula.

Household appliances that provide water and are equipped with a water reservoir, in particular beverage preparation machines such as coffee makers, tea makers, etc., usually have filter cartridges to improve the quality of water in accordance with the intended purpose. These filter cartridges often use filter media to soften the water, such as ion exchange resin, or to improve taste, such as activated carbon. In combination with filter media, the dosed introduction of additives is also provided, for example, those that are beneficial to health or improve taste, for example, the addition of minerals or vitamins, etc.

The water tanks of such prior art machines are usually provided with connecting members located at the bottom of the tank with an annular sealing surface for sealing connection with the filter cartridge connecting element provided in the water tank, which surrounds a through hole in the bottom of the tank allowing water to flow from the filter cartridge and the water tank. tank into a household device.

Similar water reservoirs and filter cartridges are described, for example, in the documents DE 10 2004 050 877 A1, EP 1 867 626 A1 and DE 197 17 056 C2.

To prevent the use of inappropriate filter cartridges, the connecting elements of the tank are equipped with coding elements, as a result of which only a filter cartridge corresponding to a given coding element can be used.

US 2010/0025317 A1 discloses a line-connected filter with an inlet line and an outlet line that are connected by a housing. The housing contains a filter cartridge with a cylinder-shaped filter medium. At the outlet of the housing there is a socket with a coding structure, while at the outlet of the cartridge there is a corresponding end cap.

EP 2 138 078 A1 discloses a connection device for permanent connection to the bottom of a container, in which connection elements in the form of a pocket are provided for connection to the bottom of the container. They are connected to the tank side fixing means in such a way that they can no longer be detached from the tank. A filter cartridge can be replaceably inserted into this connecting device, wherein the connecting device and the filter cartridge are provided with a hexagonal coding structure.

In certain embodiments, which are described, for example, in the documents WO 2008/017492 A2, EP 2 433 906 B1, EP 2 063 972 B1, EP 2 049 220 B1, EP 2 049 221 B1 and EP 2 049 218 B1 for the purpose of codification a polygonal shape is provided for the filter sealing surface and the tank sealing surface, so that the seal itself, in addition to the sealing function, also has the additional function of codification.

A disadvantage of these embodiments is the difficulty of providing a sealing function when mating an angular contour with respect to a circular contour.

It is therefore an object of the invention to improve such a water reservoir and such a filter cartridge in such a way that the implementation of said codification function is possible without disadvantages of this kind.

This problem is solved in relation to the water reservoir and the filter cartridge according to the restrictive part of claim 1 of the claims by means of characterizing features.

Further, the elements related to the water reservoir have a “reservoir” end component in their name, and the elements related to the filter cartridge have a “filter” end component in their name. Features of the preferred embodiments and improved embodiments of the invention are further described in such a way that their presence is not required, but they may occur.

The filter cartridge of the water tank according to the invention has a filter housing, the wall of which separates the inner side of the housing from the outer side of the housing, while the open inlet of the filter, intended for the flow of water from the water source, does not have an additional connecting element, which, accordingly, when installed in the water tank tank in working position would connect the filter cartridge with the internal space of the tank. Downstream of the filter inlet with respect to the direction of flow during operation, there is a device for supplying water to the interior of the filter housing, which includes at least one filter chamber provided with at least one filter medium, and ends with a filter outlet for draining water from the filter cartridge. The filter connecting element is provided with an annular connecting fitting having an annular filter sealing surface for sealing the connection of the filter cartridge with the sealing surface of the water reservoir.

The described design of the filter cartridge differs from the design of filter cartridges of devices, the housing of which provides a sealed connection to the water supply and is thus built into the water supply network.

The filter cartridge according to the invention has a filter sealing surface, the shape of which along the circumference of the annular filter connecting piece has a variable radius relative to the central axis, so that the filter sealing surface has radial convexities and/or radial concavities, wherein the convexities and/or concavities have a rounded shape, therefore there are no corners or edges.

Thanks to this, additional codification possibilities are available. This shape of the sealing surface of the filter is combined with the corresponding sealing surface of the tank, and due to the presence of variable curvature of convexes or concavities along the circumference, the connection with a hermetically sealed closure on or inside the solid surface in case of a mismatch in shape is complicated or completely eliminated. Radial convexities and/or concavities recreate the shape of a ring spring, the circumference of which can be stretched or compressed. In this case, the spring action improves the seal, since the spring pressure ensures plane pressing of the sealing surfaces of the filter and reservoir. The filter sealing surface and the reservoir sealing surface may also have the function of fixing the filter cartridge and in this case constitute a filter fixing surface or a reservoir fixing surface. The spring action makes the locking function between the filter sealing surface and the tank sealing surface more effective.

The elastic deformability of the filter sealing surface can be improved by the fact that the annular connecting piece of the filter connecting element provided with the filter sealing surface in the region of the filter sealing surface has an annular wall with an inner side and an outer side that are parallel or inclined relative to each other. Depending on whether the connection fitting is pushed over or inserted into the retaining surface of the tank, either the outer side of the wall or the inner side of the ring-shaped wall forms the sealing surface of the filter.

Since in this configuration the side of the wall opposite the sealing surface of the filter has the same shape with a correspondingly larger or smaller circumference, this wall is designed as a whole as an annular spring. Thus, the annular wall is a ring spring with peripheral sides parallel or inclined relative to each other.

Equipped with a filter sealing surface, the annular connection fitting of the filter connecting element, at least in the area of the filter sealing surface, can be made of a polymeric material with a more constant shape than an elastomer at operating temperature. Due to this rigidity, the filter connection fitting of the filter cartridge can, without any adverse change in shape, exert a pressing pressure on the sealing surface of the reservoir, providing a sealed connection.

This rigid polymer material is more resistant to shape change than elastomer, so the filter connection fitting may deform the elastomer seal on the water tank side. In this way, pressing pressure can be created. By deforming the elastomeric seal, one or more other functions of the elastomeric seal can also be realized, such as a mechanical or hydraulic function, in other words, a locking function, a valve function, and the like.

This is advantageous, for example, when the sealing surface of the filter forms the outer surface of the annular connecting piece of the filter connecting element, facing away from the central axis of the filter outlet. Despite the variable curvature of the circumference, such a filter connection, when installed in a seal on the side of a water reservoir with a corresponding radial inward sealing surface of the reservoir, is capable of exerting substantially the entire circumference of an outward clamping pressure and thereby providing the required seal and/or fixation.

In one of the improved embodiments of the invention, the configuration of convex and concavity of the sealing surface of the filter is characterized by rotational symmetry around the circumference. This ensures uniform distribution of the return force of the annular spring around the circumference and reliable fixation and sealing of the filter cartridge in the working position. A rotationally symmetrical configuration of the filter sealing surface around the circumference is formed when the convexities and/or concavities are made to periodically oscillate along the circumference line. This allows different angular positions of the filter cartridge, making it easier to attach. In addition, other technical functions depending on the angular position can be provided.

Reliable fixation of the filter cartridge in the working position is achieved due to the fact that the configuration of convex and concavity of the sealing surface of the tank and/or the sealing surface of the filter is characterized by identical angles around the entire circumference. Consequently, a ring spring made in this way can be uniformly deformed around the circumference both in the region of convexities and in the region of concavities.

The sealing effect of the filter sealing surface relative to the reservoir sealing surface can be improved by having rounded convex and/or concavity shapes, eliminating the presence of corners or ridges. Thanks to the round shape without corners or ridges in the area of the sealing surfaces, the sealing quality is improved compared to, for example, polygonal shapes of the prior art. In addition, thanks to the variable radius, it is also possible to improve the mechanical clamping and thus the fixation, for example, compared to a round shape.

The convexities and concavities of the filter fixing surface may form a wave-like curve along a circular line, the wave-like shape consisting of alternating convex circular segments forming the convexes and concave circular segments forming the concavities. By sequentially changing along the circle line, a radial elastic action is achieved.

The elastic effect of the annular spring can be further enhanced if the concave and convex circular segments at the inflection points during the transition between concave and convex curvature are tangentially conjugate.

In one particular embodiment of the invention, the arc length of the convex circular segments is greater than the arc length of the concave circular segments. Thus, the circumscribed angle of convex circular segments is also greater than the circumscribed angle of concave circular segments. Consequently, the tangential transition between different curvatures forms an acute angle with the central circumference of the ring spring, so that when deforming at the transition points there is no radial, inward or outward force.

In one particular embodiment of the invention, the convex and concave circular segments have the same segment radius. Due to this, during deformation within the segment, a comparable distribution of forces occurs.

The circular segments may be arranged such that the convex and concave circular segments lie within the outer circumferential surface and outside the inner circumferential surface, with the center of the circle of the convex circular segments lying within the inner circumferential surface and the center of the circle of concave circular segments lying outside the outer circumferential surface. This shape ensures that the circular segments located between the enveloping circles move gently relative to the enveloping circle or the center line, thereby facilitating the expansion or compression of the annular spring.

Proper operation is achieved when the radius of the inner circumference is between 5% and 15% of the radius of the outer circumference.

In addition, it turned out to be appropriate to have an option in which the radius of the convexities and/or concavities of the circular segments is from 20% to 35% of the radius of the outer envelope of the circle.

The elastic effect of such a spring ring is more pronounced when the thickness of the wall between the outer side and the inner side parallel or inclined relative to it is from 7% to 10% of the radius of the outer circumference of the circle.

In addition, such a curve path turned out to be favorable in which the inflection points between the concave and convex circular segments lie closer to the inner envelope of the circle than to the outer envelope of the circle.

The filter sealing surface may define an outer surface of the annular connection fitting of the filter connecting element facing away from the central axis of the filter outlet. Despite the variable curvature along the circumference, such a filter connection fitting, installed in an opening on the side of the water reservoir with a corresponding radially inwardly facing locking surface of the reservoir, provides an outwardly directed elastic clamping pressure substantially along the entire circumference for the purpose of proper sealing and/or fixation. Conversely, when placed over a tank-side connection fitting with a corresponding radially outward-facing tank sealing surface, the radially inward-facing filter sealing surface provides inward elastic clamping pressure over substantially the entire circumference for proper sealing and/or retention.

In one particular embodiment of the invention, both the inner side and the outer side of the filter connection piece are provided with filter fixing surfaces, one or both of which form a filter sealing surface. Such a filter connection piece can be placed in an annular slot located on the side of the reservoir, the side walls of which respectively form a fixing surface and/or a sealing surface of the reservoir.

Proper operation is ensured by a configuration including, for example, six convex and six concavity alternating along a circle whose diameter is less than 3 cm.

The filter inlet of the filter cartridge may be formed on the outside of the filter connecting piece as a ring-shaped mesh hole through which water in the water tank can enter the filter cartridge.

The improvement of the filter cartridge is achieved by providing a guide structure inside the filter connecting piece for guiding and placing the centering member located on the water tank side. Due to this, the filter cartridge, when installed in the corresponding water tank, is oriented in the axial direction and is fixed in this orientation in the operating position.

The guide structure includes at least one axially extending and parallel to the central axis guide groove for receiving at least one guide rib of the water tank side centering element, such that the guide structure, in cooperation with the corresponding water tank side centering element, causes axial movement of the filter cartridge when installed in a water tank in at least one angular position and additional fixation in this position.

For guidance and fixation in several angular positions, the guide structure can be provided with several guide grooves distributed around the circumference.

Proper guidance of the filter cartridge to a given angular position occurs when the wall of the guide grooves is rounded in such a way that the width of the groove narrows from bottom to top relative to the operating position. The direction of the filter cartridge can be improved by having the wall of the guide grooves rounded so that the width of the groove tapers radially from the inside to the outside. In combination, these tapering groove shapes form a kind of funnel for the water reservoir side centering element to fit into the groove.

Said groove shapes can be formed, for example, by internal bends of the wall of the guide structure connecting the guide grooves.

The shape of the filter sealing surface according to the invention can also help to improve the fixation of the filter cartridge by virtue of the fact that the filter sealing surface is also a filter fixing surface. The shape of the filter sealing surface, which functions as a fixing surface, according to the invention, facilitates the deformation of the filter connecting piece in the area of the filter fixing surface, since the radial convexities and/or concavities form the shape of an annular spring, the circumference of which can elastically expand or contract. Thanks to this reduced deformation due to the variable radius, it is possible to improve the mechanical clamping and thus the fixation, for example, compared to a round or polygonal shape.

The ability of elastic deformation of the filter fixing surface can be improved due to the fact that the annular connecting piece of the filter connecting element facing the filter fixing surface in the area of the filter fixing surface has an annular wall with an inner side and an outer side parallel or inclined relative to each other. Depending on whether the connection fitting is pushed onto or inserted into the tank's retaining surface, either the outer or inner surface of the annular wall forms the filter's retaining surface.

Since in this configuration the side of the wall opposite the filter fixing surface has the same shape with a correspondingly larger or smaller circumference, this wall is designed as a whole as an annular spring. Thus, the annular wall is a ring spring with sides parallel or inclined relative to each other.

In addition, the annular filter connection piece may have an outer and/or inner wall that is beveled relative to the vertical, so that the outer wall and the inner wall converge from top to bottom relative to the operating position of the filter cartridge. Thereby, a guide is formed that facilitates insertion of the connecting piece into the gap between two mating surfaces on the tank side, wherein the surfaces on the tank side can form at least partially the inner and/or outer sealing surface of the tank.

Accordingly, the beveled outer wall may have an outer sealing surface of the filter and/or the beveled inner wall may have an inner sealing surface of the filter and enter into a sealed, form-fitting connection with the corresponding sealing surface of the reservoir.

In a water tank for a household appliance corresponding to the filter cartridge described above, there is a tank bottom, and at the bottom of the tank there is provided an annular sealing surface of the tank for sealing the filter cartridge, which covers a through hole in the bottom of the tank for the flow of water from the filter cartridge through the bottom wall tank into a household device. To effectively interact with the filter sealing surface described above, the shape of the reservoir sealing surface is also characterized by a variable radius of a circle about the central axis, so that the reservoir sealing surface has radial concavities and/or radial convexities.

This leads to the coding options shown above for the filter cartridge on the water tank side. Due to this shape of the reservoir sealing surface, a filter cartridge with a corresponding filter sealing surface as described above can be used in the water reservoir. To coordinate with the filter cartridge and the connection on the tank side, the choice of materials and their arrangement and therefore the coding element can also be decisive in creating the specified shape. In this way, the presence of corners or ridges in the area of the sealing surfaces can be eliminated, thereby improving the quality of the seal, for example, compared to polygonal shapes of the prior art. Thanks to the variable radius, it is also possible to improve the mechanical clamping and therefore the fixation, for example, compared to a round shape.

The sealing surface of the tank is made corresponding to the sealing surface of the filter described above in such a way that the annular sealing surface of the tank forms the inner surface of the connecting element of the tank facing the central axis of the through hole of the tank. Such a sealing surface of the reservoir corresponds to the shape of the connecting piece on the side of the filter, whereby it can be inserted into the connecting member of the reservoir. Despite the variable curvature of the circle, when the filter connection piece is inserted into the tank connection element with the sealing surface of the tank facing radially inward, the desired seal is achieved substantially along the entire circumference.

To use a filter cartridge on which the convexities and/or concavities of the sealing surface of the filter, as described above, are made to periodically oscillate along a line of a circle, the concavity and/or convexity of the sealing surface of the reservoir are also made to periodically oscillate along a line of a circle, respectively, along the sealing surface of the filter. Likewise, in order to match the corresponding filter sealing surface, the concavities and/or convexities of the filter sealing surface can be rounded.

To match the corresponding filter sealing surface, the sides of the reservoir sealing surface may include six concavities and six convexes alternating along the line of a circle whose diameter is less than 3 cm.

By taking into account all the details of matching the sealing surface of the container with the correspondingly shaped sealing surface of the filter, the advantages described above in relation to the filter cartridge are achieved.

The annular reservoir connector may include an annular elastomeric seal that is pre-formed with radial convexities and/or radial concavities. Such a container connection element is advantageous in particular in combination with a filter cartridge in which the ring-shaped filter connection piece in the area of the filter sealing surface is made of a polymer material that retains its shape at operating temperature. When installing the filter cartridge, the elastomeric seal is exposed to a polymer material that is resistant to change in shape on the side of the filter cartridge.

Preferably, a reservoir sealing surface is located on the inner side of the radial convexities and/or radial concavities of the elastomeric seal.

In addition, it is advantageous if the sealing surface of the elastomeric seal reservoir has a beveled outline, converging from top to bottom towards a central axis. Due to these contours, the elastomer seal is subjected to increasingly elastic outward deformation during installation of the filter cartridge and, through the resulting return force, exerts a pressing pressure that ensures a proper seal.

By deforming the elastomeric seal, in addition to the locking function and the sealing function, one or more additional functions can be performed. For example, it may be a hydraulic function such as a valve function, etc.

From the point of view of using the elastomer seal, it is advantageous if the bottom of the container is provided with a clamping ring and an elastomer seal inserted into the clamping ring. In such a case, the outer clamping ring prevents the expansion of the elastomer seal so that the elastic return force of the elastomer is almost entirely used to create the clamping pressure.

To prevent leakage between the clamp ring and the elastomeric seal, the elastomeric seal may have a sealing surface for sealing the elastomeric seal to the clamp ring. In addition, the elastomeric seal may have a sealing surface for sealing the clamp ring to the bottom of the reservoir.

Preferably, the bottom of the reservoir is provided with a bypass channel for unfiltered water, which flows out from the interior of the water reservoir through the clamp ring and the elastomeric seal. This allows drainage from the water tank when there is no filter cartridge present. Drainage may be required when a filter cartridge is not available, or operation without a filter cartridge is required, for example during maintenance such as cleaning or descaling of related equipment. Cleaning or descaling agents used in such cases must not get into the filter cartridge.

The bypass channel may include, for example, an annular gap in the elastomeric seal allowing a circumferentially distributed flow of water into the outlet conduit.

Preferably, the elastomeric seal includes a shut-off element by means of which the bypass channel can be closed, in particular when installing a filter cartridge in the elastomeric seal. Thus, by using a suitable filter cartridge, the bypass channel can be closed without any additional action.

For example, the elastomeric seal may have a form in which the closure member includes two opposing annular sealing surfaces in an annular gap that can close the annular gap when the elastomeric seal is deformed. If the inner sealing surface of these two annular sealing surfaces expands when the filter cartridge is installed in the elastomer seal, a positive connection occurs with the outer annular sealing surface and the bypass channel is closed.

To facilitate securing the clamp ring and/or elastomeric seal to the bottom of the tank, the clamp ring may include a locking mechanism for securing to the bottom of the tank.

In addition, a centering element for inserting a filter cartridge may be provided at the bottom of the tank. The centering element ensures that the filter cartridge is inserted into the correct working position during installation. In addition, with this configuration, the centering element can provide additional codification, providing reliable assurance that only the correct filter cartridge will be installed. In addition, the centering element can also perform a locking function, for example against twisting or distortion of the filter cartridge. Unintentional detachment of the filter cartridge can be prevented by means of suitable friction surfaces, so that when removing the filter cartridge a suitable frictional force must be overcome. The centering element may contain additional fixing elements.

To connect the centering element with the elastomer seal, the centering element can be equipped with a support plate lying in the receiving socket of the elastomer seal and abutting its sides. This ensures that the centering element is secured to the elastomer seal.

If a bypass for unfiltered water is provided, the centering element may have a bypass hole, for example in the support plate, which opens into the central drain.

Preferably, the centering element includes a centering core projecting upward from the centering element support plate, having an annular outer surface that has a variable radius about a central axis, such that the outer surface has radial convexities and/or radial concavities. The centering core matches the outer contour of the elastomer seal and the filter connection fitting of the corresponding filter cartridge.

In one of the preferred embodiments of the invention, concavity and/or convexity of the outer surface of the centering core periodically alternate along the circumference line. This configuration corresponds to the shape of the corresponding elastomeric seal and leaves only an annular gap free with concavities and/or convexities for the introduction of the corresponding filter cartridge. This form of implementation also prevents the use of connecting elements with a different geometry inside the elastomer seal, hence the codification function is improved. In addition, along these convexities and/or concavities, support for the inner side of the filter connecting piece can be provided in order to securely deform the elastomer seal on the opposite outer side when installing the filter cartridge.

The concavities and/or convexities of the outer surface of the centering core may have a rounded shape corresponding to the shape of the elastomeric seal and/or the filter connecting piece.

With the appropriate shape of the elastomeric seal and/or filter connecting fitting, on the outer surface of the corresponding centering core there are six concavities and six convexes along a circle with a diameter of less than 3 cm.

In one of the preferred embodiments of the invention, a step and an inwardly displaced protrusion are provided above the outer surface with concavities and/or convexities, which further extends into the filter cartridge and thus has a large axial guide length.

To prevent axial compaction at this stage with another, unsuitable filter cartridge, there may be at least one tooth above the annular outer surface projecting upward along the circumferential surface.

Above the annular outer surface, at least one through hole may be provided in the centering element leading to a through hole of the reservoir connecting the water inlet of the filter cartridge with the water outlet, which can only be closed by a sealing filter cartridge according to the invention.

Guidance and axial centering can be improved by providing at least one guide rib in the centering element above the annular wall. Water may flow near this fin, or in the case of multiple guide fins, between them. When putting on the filter cartridge, the guide ribs can fit into the guide grooves described above.

Another guide means for centering the filter cartridge when installing it is provided by the fact that the guide rib or guide ribs on the upper side are beveled towards the central axis. When installing, the filter connection piece can run along the bevels until it reaches a centered position.

The elastomeric seal may also have a sealing surface to seal the clamp ring against the bottom of the reservoir to prevent unwanted flow of water from the water reservoir through the clamp ring on the filter cartridge.

In addition, the clamping ring can be equipped with a lock for fastening the clamping ring to the embedded part or to the bottom of the tank. This makes installation of the clamping ring easier. If the centering element, as described above, is also secured with a clamping ring, then its installation and, under certain conditions, also the installation of the water tank valve located underneath it are simplified.

The design of the water reservoir is simplified if at the bottom of the reservoir there is provided a mounting part belonging to the bottom of the reservoir, which includes a part intended for attaching a filter cartridge from the side of the water reservoir. Using the embedded part, dissimilar connecting structures can be easily created with the same water reservoir design including different embedded parts. In addition, different requirements can be selected regarding the processing tolerance of the water tank and the corresponding embedded part.

In this case, the embedded part may preferably include an elastomer seal and/or a clamping ring and/or a centering element and/or at least partially a bypass channel. All of the essential tank connecting structures may be included in the insert so that the match between the water reservoir and a particular filter cartridge can only be ensured by selecting the appropriate insert.

Examples of the invention are presented in the drawings and are further explained in more detail with reference to the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In particular, the figures show:

Fig. 1 is a perspective view of the bottom of a tank with a filter cartridge installed according to the prior art,

Fig. 2 is a perspective view with spatial separation of the parts of the bottom of the tank with a centering element and a clamping ring,

Fig. 3 is a perspective view of the bottom of the tank according to FIG. 2 with inserted centering element and inserted clamping ring,

Fig. 4 is a top view of the bottom of the tank according to FIG. 2 and 3,

Fig. 5 is a side perspective view of the connecting area of the filter cartridge,

Fig. 6 is a perspective view of the connecting area of the filter cartridge obliquely from below,

Fig. 7 is a perspective view of the connecting fitting of the filter cartridge, cut off at a height, inserted into the bottom of the tank,

Fig. 8 is a perspective view of a filter cartridge cut at the height of the guide grooves and inserted into the bottom of the tank,

Fig. 9 is a perspective view of a filter cartridge inserted into the bottom of a tank,

Fig. 10 is a perspective view of the centering element,

Fig. 11 is a sectional view of the bottom of the tank without a filter cartridge with the valve of the water tank open,

Fig. 11a and b are enlarged views of two parts of FIG. 11 to explain the closing bypass channel in the tank seal,

FIG. 12 is a sectional view of the bottom of the tank according to FIG. 11 with inserted filter cartridge,

Fig. 12a is an enlarged view of part of FIG. 12 to explain the closed bypass channel,

Fig. 13 is a schematic front view of a filter connection fitting according to the invention,

Fig. 13a is an enlarged view of part of FIG. 13 and

Fig. 14 is a fragment showing the connecting area of the filter cartridge for explaining the guide means formed by beveling the guide rib.

DETAILED DESCRIPTION OF THE INVENTION

In fig. 1 shows a conventional design of a water tank 1 of a beverage preparation machine such as a coffee maker, for example a coffee vending machine of the prior art. The water tank 1 includes a tank bottom 2 and a water tank wall 3 partially shown in dashed lines. A filter cartridge 4 is installed in the water tank 1, including a filter housing 5. The connection between the tank bottom 2 and the filter cartridge 4 is provided by a tank connecting element 6 on the water tank side and a filter connecting element 7 on the filter side.

The filter cartridge 4 is located in the internal space 8 of the water tank 1, that is, during operation of the device it is completely or partially in the water, the supply of which is available in the water tank 1. From below, the connecting fitting 9 of the filter of the water tank 1 protrudes from the bottom of the water tank 1 for connection water tank 1 to a beverage preparation machine, which is not shown in the drawing.

In fig. 2 shows a round cutout of the bottom 2 of the tank, with a clamping ring 10 and a centering element 11 inserted into the recess 12 of the bottom 2 of the tank. In fig. 2 also shows a reservoir valve body 13 with an O-ring seal 14 from which two rods 15 project upward. The clamp ring 10 is provided with an elastomeric seal 16.

In fig. 3 and 4, the clamping ring 10 and the centering element are shown inserted into the bottom 2 of the tank. It can be seen that the rods 15 can pass through the centering element and thus constitute a codification element for matching the water tank and the machine connecting element, which, when installing the water tank, can actuate the tank valve body 13. In addition, in FIG. 4 it is clearly seen that the elastomeric seal 16 forming the reservoir seal 17 is an annular seal of variable radius R relative to the central axis A, so that the inner surface of the reservoir seal 17 that forms the reservoir sealing surface 18 has radial concavities 19 and radial convexities 20. The first sealing surface 18 of the tank is also the fixing surface of the tank.

In fig. 5 shows the connecting area 21 of the filter cartridge 22. The filter connecting fitting 23 forms a ring surrounded by an outer ring 24 with axially running projections 25 and depressions 26. Between the inner ring 23 and the outer ring 24 there is an annular mesh inlet 27, through which the filter cartridge receives water. The outer surface 28 and the inner surface 68 of the filter connecting piece 23 are equipped with convex 29 and concave 30 corresponding to the sealing surface 18 of the tank. The outer surface 28 and/or the inner surface 68 of the filter connecting piece 23 can simultaneously serve as a filter fixing surface.

In the view shown in FIG. 6, in addition to the above-described parts of the connecting area 21 of the filter cartridge 22, a configuration of a guide structure 31 of the filter cartridge 22 is shown for receiving the centering member 11. The guide structure includes guide grooves 32 coaxially arranged with the faces 33 of the polyhedral ring 34, in this case, for example, six guide grooves coaxial to the six faces of the hexagon-shaped ring. As shown in FIG. 7 in the cross-sectional image, when viewed from above, the cut plane passes through the polyhedral ring 34.

From bottom to top, internal bends 35 enter the inner space of the filter cartridge, lying between the edges 33 and the guide grooves 32. The internal bends 35 form the side walls 36 of the guide grooves 32. Thanks to the curved shape, the walls 36 of the guide grooves 32 narrow in the axial direction from bottom to top (relative to the working position) and in the radial direction from the inside to the outside. As shown in FIG. 8 in the sectional view, when viewed from above, the cut plane passes at a height where the guide grooves 32 are already clearly visible. In the center, a pressure line adjoins the internal space, through which water entering the filter cartridge 22 is directed upward to the filtration section.

In fig. 9 shows the filter cartridge 22 as a whole, which is provided with a filter housing 37 having an optional side metering hole 38 and the described water connection on the bottom side. The optional dosing hole 38 is only provided in the case of a filter cartridge, also intended to introduce additives such as minerals, vitamins, etc. into the water. from the dosing chamber filter located in housing 37. Since such a metering chamber within the filter housing 37 is closed with respect to the filtration section, this aspect is not significant from a filtration point of view. The filter cartridge according to the invention can also be simply designed without a dosing chamber and a corresponding dosing opening 38. In FIG. 9, first of all, you can see the operating position, to which the information given above and below in the present description relates.

In fig. 10 is a perspective view of the centering element 11. The centering element is provided with a support plate 39, which, when mounted, lies in the receiving seat of the elastomeric seal and rests against it on its sides. Projecting upward from the support plate 39 is a centering core 40 having an annular outer surface 41 which forms a second locking surface of the reservoir. The outer surface 41 has a variable radius along its circumference relative to the central axis A, thus the outer surface 41 has radial concavities 42 and convexes 43. Therefore, the outer surface 41 is consistent with the corresponding shape of the filter connecting piece 9.

To better coordinate the concavity 42 and convex 43 of the outer surface 41, they are made to periodically oscillate along a circle and have a rounded shape. In the illustrated embodiment, according to the illustrated embodiment, the filter cartridge 22 is provided with six concavities 42 and six convexes 43 on the line of the circle with a diameter of less than 3 cm. To match with the other filter cartridge, the outer surface 41 or the second fixing surface of the reservoir should be modified accordingly.

As a result of such matching of the shape of the outer surface 41 of the centering core 11 in the mounted state, only the annular gap between the outer surface 41 and the elastomeric seal 16 remains open for the introduction of the connecting fitting 23 of the filter. This provides an additional codification that prevents the use of an incorrect filter cartridge. In addition, it is thus possible to support the filter connecting piece 23 with its inner side on the outer surface 41 of the centering core. Therefore, the pressing pressure of the filter connecting piece on the elastomer seal 16 along the variable shape can be uniformly increased over the entire circumference.

Above the annular outer surface there is at least one protruding upward tooth 44. One or more teeth 44 are made on the step 45 of the centering core 40. In addition, in accordance with the shape of the outer surface 41 at some distance from the teeth 44, elevations 4 6 relative to the step 4 5 are designed in such a way that there is a free space 47 between the teeth and elevations 46. The tooth or teeth 44 and/or elevations 46 may prevent the application of a seal in violation of the codification. There is also a through hole 48 above the outer surface 41, which, when the centering element 11 is mounted, leads into the through hole of the reservoir. Through the through hole 48, the water filtered in the filter cartridge 22 can be drained from the water reservoir.

The support plate 39 has one or more through-bottom holes 49 under the outer surface 41. Unfiltered water can be drained from the water reservoir through the bottom holes. Under the elevations 46 inside the wall with the outer surface 41 there is a free space 50 for housing the reservoir valve housing 13.

Above the annular outer surface 41 there are guide ribs 51, which, as in the illustrated embodiment, can be beveled at the top. The guide bevels 52 thus formed facilitate the insertion of the guide ribs 51 into the guide grooves 32 of the filter cartridge 22. In the sectional view of FIG. 4, the guide bevels 52 of the guide ribs 51 in the mounted filter cartridge 22 are clearly visible.

In fig. 11, 11a, 11b, 12 and 12a, the parts of the water tank 1 intended for attaching a filter cartridge are shown assembled without a filter cartridge 22 or with a filter cartridge 22. The clamping ring 10 is equipped with a locking protrusion 53, which ensures its fastening to the bottom 2 of the tank and with which it rests against the edge 54 of the bottom of the water reservoir. The elastomeric seal 16 has a bottom portion 55 that engages with a clamp ring 10, causing the elastomeric seal 16 to be held by the clamp ring 10 at the bottom 2 of the tank.

The elastomeric seal 16 has a sealing surface designed to seal against the bottom 2 of the tank, which in this case is implemented as a sealing boss 56. To seal the seal between the elastomeric seal 16 and the clamp ring 10, the enveloping sealing surface can be provided at different locations. In the exemplary embodiment shown, there is an O-ring 57 above the elastomeric seal 16 that is sealed in the seal groove 58 of the clamp ring.

The elastomeric seal 16 includes an outer ring 59 and an inner ring 60 connected and formed as a single unit. The shape of the outer ring 59 and the inner ring 60 follows the shape of the variable-radius circle of the clamping ring 10, the filter connecting fitting 23 and the elastomeric seal 16 and the concavities and convexities formed by them. The outer ring 59 is stepped and includes an o-ring 57 and a sealing boss 56. The outer ring 59 is also provided with one or more bypass holes 61 through which unfiltered water in the flow direction P1 can enter the annular gap 62 between the outer ring 59 and the inner ring 60. The bypass hole 61 of the elastomer seal 16 in the assembled state is located immediately after the bypass hole 63 of the clamping ring 11, which can be seen, for example, also in FIG. 1 and 3. Through the bypass hole 63, unfiltered water can flow in the direction P2 through the annular gap 62 from the water tank 1 to the corresponding beverage machine.

On the underside of the inner ring 60 there is a seal lip 64 lying against the sealing surface 65 of the outer ring 59. In the relaxed state of the elastomeric seal 16, the annular gap 62 between the outer ring 59 and the inner ring 60 is open at the bottom, as shown in FIG. 11, and the unfiltered water directed to the bypass can flow out of the annular gap 62 in the flow direction P2. In this state, the inner side 66 of the inner ring 60 forming the water reservoir seal 17 is slanted downward. This bypass form is clearly shown in the enlarged views of Figs. 11a and b.

When installing the filter cartridge with the filter connection piece 23, the elastomeric seal 16 is deformed, the inner side 66 is deflected outward and runs essentially vertically along the filter connection piece. In this case, the working edge 64 of the seal is pressed against the opposing sealing surface 65 and, thus, closes the annular gap 62 and, consequently, the bypass flow through the bypass holes 61, 63. When deformed, a clamping pressure occurs, ensuring that the sealing surface 17 of the tank is pressed against the sealing surface 28 filter and, at the same time, the sealing lip 64 to the sealing surface 65. This condition is shown in FIG. 12 and fig. 12a.

In fig. 11 and fig. 12, the reservoir valve body 13 is raised, not shown in detail, by the stop of the corresponding machine towards the return spring 67 into the free space 50 and is in the open state that occurs when the water reservoir is installed on this machine. When the water reservoir is removed, the valve body 13 closes downward under the action of the return spring 67.

The sealing surface 18 of the reservoir is formed by the inner side 66 of the elastomeric seal and is also the first locking surface 18 of the reservoir. As already described above, to this side, under the action of pressing pressure, when the filter cartridge 5, 22 is installed in place, a first filter fixing surface formed by the filter sealing surface 28 is adjacent, which deforms the elastomeric seal 16 in such a way that a positive connection occurs, providing fixation and compaction.

In this case, the outer surface 41 forming the second fixing surface of the filter is adjacent to the second fixing surface 68 of the filter (see Fig. 5), formed by the inner surface of the connecting fitting 23 of the filter. This form-fitting connection is also established under the action of clamping pressure. According to the form of the filter connection piece 23 according to the invention, it has an annular wall 69, which can be elastically stretched if necessary. In this way, the permissible deviations can be balanced and, through appropriate deformation, a secure fixation can be ensured. Parallel or inclined relative to each other, the first fixing surface and the second fixing surface 68 form an annular wavy wall 69 of the connecting fitting 23 lying between them, which is an annular spring 70. The second filter fixing surface 68 can also serve as a second filter sealing surface.

The filter connection fitting corresponding to the front view shown in FIG. 13, as well as an enlarged image of its part shown in FIG. 13a, has the indicated wave-like shape with convexities 29 and concavities 30. The annular wall 69 of the filter connecting piece 23 of thickness W on the outer side 71 has a first fixing surface and on the inner side 72 has a second fixing surface 68. The outer side 71 and the inner side 72 of the wall on presented are parallel, but in the axial direction they are inclined to each other, which is further explained below. The wave-like shape is clearly represented by the dotted center line 73.

The center line 73 extends in a wave-like manner between the outer circumference 74, whose variable wave radius is characterized by larger values, and the inner circumference 75, the variable wave radius of which is characterized by smaller values. The convexities 29 and concavities 30 of the centerline 73 form wave crests in the form of convex circular segments 76 and wave troughs in the form of concave circular segments 77. In the illustrated embodiment, all circular segments 76, 77 have the same segment radius S. The midpoints 78, 79 of the circular segments 76, 77 in the case of a convex circular segment 76 lie inside the inner enveloping circle 75, and in the case of a concave circular segment 77 lie outside the outer enveloping circle 74. The convex circular segments 76 and the concave circular segments 77 merge into each other tangentially and uniformly distributed around the circumference, so that a shape characterized by rotational symmetry is formed. In the illustrated embodiment, there are six convex circular segments 76 and six concave circular segments 77 alternating at an angular pitch of 30°, that is, the convex circular segments 76, like the concave circular segments 77, are spaced apart by an angle a of 60°.

By selecting the radius of the segments and the resulting position of the corresponding midpoints 78, 79, a relatively flat centerline is obtained, undulating along the central circle 80. The center line 73 intersects the central circle 80 at an obtuse angle β. Due to this, the length of the arc of convexities 2 9 is significantly greater than the length of the arc of concavities 30, and the angle y described by the arc of the segment of convexes 29 is significantly greater than the described angle δ of concavities 30. Thanks to this shape, the elastic effect of the connecting fitting 23 of the filter is improved.

For comparison, a drawing of a circular segment 81 is also shown, the midpoint of which lies directly on the center line 73. This curve path, not implemented in this embodiment, is characterized by significantly smaller radii of the segments and a substantially perpendicular course of the center line 73.

Sufficient elastic force was achieved at a wall thickness such that the radius of the inner circumference 75 is between 5% and 15% of the radius of the outer circumference 74, and the radius of the convex and/or concave circular segments is between 20% and 35% of the radius of the outer circumference. 74. The thickness W of the wall between the outer side 71 and the parallel (relative to the operating position) or inclined relative to the inner wall side 72 is preferably from 5% to 15% of the radius of the outer circumference of the circle 74.

The presented example is characterized by a radius of the outer envelope of the circle 7 4 of about 11 mm and a radius of the inner envelope of the circle 75 of about 9.75 mm. In this case, the radius of the convex and concave circular segments is 3.08 mm, and the thickness of the wall between the outer side 71 and the parallel or inclined relative to the inner wall side 72 is about 0.9 mm.

As shown in FIG. 14, the outer 71 and/or inner 72 wall of the filter connecting piece 23, which, depending on the embodiment, also form one or two sealing surfaces 28 of the filter, are beveled relative to the vertical at an angle ω1 or ω2 and converge from top to bottom relative to the working position of the filter cartridge 4, 22. Such bevel or bevels at an angle ω1 and/or ω2 form a guide means for introducing the connecting fitting 23 into the annular gap between the elastomeric seal 16 and the outer surface 41 of the water tank 1.

List of positions in the drawings:

1 Water tank

2 Bottom of the water tank

3 Side wall of water tank

4 Filter cartridge

5 Filter housing

6 Tank connection

7 Filter connection element

8 Interior space

9 Filter connection fitting

10 Clamping ring

11 Centering element

12 Deepening

13 Tank valve body

14 Seal

15 Rod

16 Elastomeric seal

17 Water tank seal/O-ring

18 Tank sealing surface

19 Concavity

20 Bulge

21 Connecting area

22 Filter cartridge

23 Filter connection/inner ring 2 4 Outer ring

25 Ledge

26 Depression

27 Mesh inlet

28 Filter sealing surface/outer surface

29 Bulge

30 Concavity

31 Guide structure

32 Guide groove

33 Edge

34 Polyhedral ring

35 Internal bend

36 Wall

37 Filter housing

38 Dosing hole

39 Support plate

40 Centering core

41 Outer surface

42 Concavity

43 Bulge

44 Prong

45 Stage

46 Rise

47 Free space

48 Through hole

49 Through hole in the bottom

50 Free space

51 Guide rib

52 Guide bevel

53 Locking lug

54 Bottom rib

55 Bottom section

56 Sealing thickening

57 O-ring

58 Sealing groove

59 Inner ring

60 Outer ring

61 Bypass hole

62 Annular gap

63 Bypass hole

64 Seal lip

65 Sealing surface

66 Inner side

67 Return spring

68 Second fixing surface/inner surface

69 Wall

70 Ring spring

71 Outer side of the wall

72 Inner side of the wall

73 Centerline

74 Outer circumference circle

75 Inner circumference circle

76 Convex circular segment

77 Concave circular segment

78 Midpoint

79 Midpoint

80 Central circle

81 Circular segment

84 Tank through hole

A Axis

W Wall thickness

S Segment radius

P1 Flow direction

P2 Flow direction

Claims (21)

1. A water tank (1) for a household appliance with a connection for a filter cartridge (22), wherein the bottom of the tank has an annular sealing surface for sealing the connection of the filter cartridge (22), and the sealing surface surrounds a through hole in the bottom of the tank for water flow. from the filter cartridge (22) through the wall of the bottom of the tank into a household device, characterized in that the sealing surface (18) of the tank along its circumference has a variable radius relative to the central axis, so that the sealing surface (18) of the tank has radial concavities (19) and radial convexities (20), while convexities (20) and concavities (19) have a rounded shape, and concavities (19) and convexities (20) are made periodically oscillating along a circle line. 2. A water tank (1) for a household device according to claim 1, characterized in that the water tank (1) is equipped with a filter cartridge (22) having a filter housing (37), the wall of which separates the inner side of the housing from the outer side of the housing, with This provides for an inlet port (27) of the filter that is open during operation of the filter cartridge (22) relative to the external environment of the filter housing (37), while relative to the direction of flow during operation, after the inlet opening (27) of the filter, a device is provided for supplying water inside the filter housing (37). , which has at least one filter chamber equipped with at least one filter medium, and which ends in a filter outlet for draining water from the filter cartridge (22), wherein a filter connecting element is provided with an annular connecting fitting (23) having an annular a sealing surface (28) of the filter for sealing the connection of the filter cartridge (22) with the sealing surface of the water tank, while the shape of the sealing surface (28) of the filter along the circumference of the annular connecting fitting (23) of the filter has a variable radius relative to the central axis, so that the sealing surface ( 28) of the filter has radial convexities (29) and radial concavities (30), while the convexities (29) and concavities (30) have a round shape, and the convexities (29) and concavities (30) are made periodically oscillating along a circle. 3. The water reservoir (1) according to claim 2, characterized in that, provided with a sealing surface (28) of the filter, the annular connecting piece (23) of the filter connecting element, at least in the area of the sealing surface (28) of the filter, consists of a polymer material with constant shape at operating temperature, in particular more rigid than an elastomer. 4. Water reservoir (1) according to claim 2 or 3, characterized in that the sealing surface (28) of the filter forms the outer surface of the annular connecting piece (23) of the filter connecting element, facing away from the central axis (A) of the filter outlet. 5. Water tank (1) according to one of paragraphs. 2-4, characterized in that along the circle line there are six convexities (29) and six concavities (30), which have a diameter of less than 3 cm. 6. Water tank (1) according to one of paragraphs. 2-5, characterized in that a guide structure is provided inside the filter connecting piece (23) for guiding and placing the centering element (11) located on the tank side. 7. The water tank (1) according to claim 6, characterized in that the guide structure (31) includes at least one guide groove (32) for accommodating at least one guide rib (51) of the centering element (11) of the water tank side . 8. Water tank (1) according to claim 7, characterized in that the wall of the guide grooves (32) is rounded in such a way that, relative to the working position, the width of the groove narrows from bottom to top. 9. Water reservoir (1) according to claim 7 or 8, characterized in that the wall of the guide grooves (32) is rounded in such a way that the width of the groove narrows from the inside to the outside. 10. Water tank (1) according to one of paragraphs. 2-9, characterized in that the ring-shaped connecting fitting (23) of the filter connecting element has outer (71) and/or inner (72) walls, which in the operating position of the filter cartridge are beveled relative to the vertical at an angle ω1 and/or ω2 so that the outer wall (71) and the inner wall (72) of the filter cartridge converge from top to bottom. 11. Water tank (1) according to one of the previous paragraphs, characterized in that the sealing surface (18) of the tank forms the inner surface of the ring-shaped connecting element of the tank facing the central axis of the through hole of the tank. 12. Water reservoir (1) according to one of the preceding claims, characterized in that the annular connecting element of the reservoir includes an annular elastomer seal (16), on which radial convexities (19) and radial concavities (20) are pre-formed. 13. Water tank (1) according to one of the previous paragraphs, characterized in that on the inner side of the radial convexities (19) and radial concavities (20) of the elastomeric seal (16) there is a sealing surface (18) of the tank. 14. Water tank (1) according to one of the previous paragraphs, characterized in that the sealing surface (18) of the tank has a beveled outline shape converging from top to bottom towards the central axis (A). 15. Water tank (1) according to one of the previous paragraphs, characterized in that the bottom (2) of the tank is equipped with a clamping ring (10) and an elastomer seal (16) inserted into the clamping ring (10). 16. Water tank (1) according to one of the previous paragraphs, characterized in that a bypass channel is provided in the bottom of the water tank (1) for unfiltered water from the water tank (1), which passes from the internal space of the water tank through the clamping ring and through the elastomeric compaction 17. Water tank (1) according to one of paragraphs. 12-16, characterized in that the elastomeric seal (16) includes a shut-off element for closing the bypass channel. 18. Water tank (1) according to one of paragraphs. 15-17, characterized in that the clamping ring (10) includes a lock (53) for fixing the clamping ring (10) on the bottom (2) of the tank. 19. Water tank (1) according to one of the previous paragraphs, characterized in that a centering element (11) is provided at the bottom of the tank for insertion into the filter cartridge (22). 20. Water reservoir (1) according to one of the preceding paragraphs, characterized in that at least one protruding tooth (44) is located above the annular outer surface (41). 21. A water tank (1) according to one of the preceding claims, characterized in that at the bottom of the tank there is provided a mounting part belonging to the bottom of the tank, which includes a part for attaching a filter cartridge (22) on the side of the water tank.