GB2346568A

GB2346568A - Device for preparing liquids, with a filter cartridge

Info

Publication number: GB2346568A
Application number: GB0001471A
Authority: GB
Inventors: Detlev Weyrauch; Ilko Mandelkow
Original assignee: Brita SE
Current assignee: Brita SE
Priority date: 1999-02-11
Filing date: 2000-01-21
Publication date: 2000-08-16
Also published as: DE19905601A1; IL134426A0; GB0001471D0; PL337939A1

Abstract

A device for preparing liquids comprises an inlet funnel 1, and a filter cartridge 2 which is sealed to the inlet funnel by means of a sealing element 12, the filter cartridge main part containing a treatment medium and the sealing element having a smaller radial dimension than the largest radial dimension of the cartridge. The filter cartridge may have an upper part 4 with inlet apertures which may be moved into sealing engagement with a sealing seat 19 of the inlet funnel by a fixing ring 34. The sealing element, for example o-ring, preferably acts radially outwards, and may be protected from mechanical damage by the periphery of the upper part of the cartridge being rotationally non-symmetric and the sealing seat having a corresponding periphery (Figure 3 and 4). Alternatively the inlet funnel may contain the upper part of a filter cartridge, and the filter cartridge main part may be moved pivotably into sealing engagement with the upper part (Figures12-17).

Description

2346568 Device for preparing liquids with a cartridge

---------------------------------------------- The invention relates to a device for preparing liquids with an inlet funnel, a sealing ring connected thereto in a sealing manner and with a filter cartridge which is sealed against the sealing ring by means of a sealing element, and which is provided with an upper cartridge part with inlet apertures and an outlet sieve connected by means of side walls, between which a granular treatment medium is retained.

The invention generally relates to the preparation of liquids, that is to say to purifying, filtering, removal of bacteria, change of taste, of odour and so forth. Filtering is more of an umbrella term and the filter cartridge described is a container with an inlet sieve and outlet sieve, between which the granular treatment medium is retained. Such media in granular form, for example ion exchangers, activated charcoal, minerals, and mixtures of these, are known. With the device according to the invention and its filter cartridge, liquids are prepared, and for example also made germ-free.

A known preparation device of the type previously described serves to purify water, preferably with the aid of a mixture of ion exchangers and activated charcoal. Here, in the base aperture of the inlet funnel, against a circular sealing ring preferably set at an angle with respect to the vertical central axis, there is sealed a similarly inclined outer edge of the filter cartridge as a sealing element. In this way the water located over the filter cartridge and in the inlet funnel is compelled to go through the inlet apertures in the upper cartridge part and through the treatment medium. This is a gravity operated device, that is to say the height of the column of liquid provides the pressure with which the liquid to be purified is pushed through the treatment medium in the filter cartridge from above to below.

It has been shown that the outer edge of the known filter cartridge sealing element is vulnerable as a sealing element acting radially outwards. When such a filter cartridge hits a machine part during the manufacturing process, or falls on the floor, firstly, and with certainty, this sealing element, namely the outer edge of the filter cartridge having the largest diameter, will be damaged. Scoring or denting in this sealing element produces a certain amount of bypassing, so sealing is not completely provided. Known filter cartridges are made from polypropene which can be permanently distorted by impacts from the outside. Such dents, which cause leakage, play only a subordinate role in softening water, in improving its taste or odour and in similar treatments. These leakages with the known preparation devices can thus be accepted without any problem.

Whether a radially acting sealing element in the form of an O-ring made from rubber or another elastomeric material is constructed opposite a counter sealing seat, or two plastics surfaces with an equivalent shape are pressed against one another, sealing is always significantly optimised in that one part is twisted with respect to the other. In the known instance, the cartridge provided with the rotationally symmetrical sealing element is inserted from above into the aperture in the funnel base, and then rotated slightly by hand. If it is now desired that the sealing be improved, it is obvious to increase the twisting forces, wherein even better sealing will be obtained when an O-ring located externally on the cartridge presses against a sealing ring located inside on the aperture of the funnel base. However, it has been shown that with such movements even after being used a few times, that is to say removal of the filter cartridge from the inlet funnel and subsequent insertion of another or a newly filled filter cartridge, the sealing elements were damaged or even destroyed. Wear also has its effects.

An object of the invention is therefore to further develop the device described in detail in the introduction for preparation of liquids such that the sealing means

3 between the inlet funnel and filter cartridge aim to provide leak-free operation and are protected mechanically even during an extended period of use.

The solution of the object is obtained according to the invention in that the sealing element acting radially outwards is fitted to a periphery of the upper part of the cartridge, and has smaller radial dimensions than the largest radial dimension of the filter cartridge, and in that means are provided for moving the filter cartridge in the sealing ring on the inlet funnel. Whether the sealing element acting outwards is a smooth annular surface, or an O-ring, or a differently configured element, is of no consequence when according to the teaching of the invention it is ensured that at the height of this sealing element the upper part of the cartridge has a smaller circumference, and has a smaller diameter along this circumference than the largest portion of the filter cartridge. If the latter has a cup shape, its largest radial dimension is located on the upper, free, outer edge. A filter cartridge according to the novel invention is pushed from below into the aperture of the funnel base, as the diameter of the aperture in the funnel base corresponds to that of the sealing element on the upper part of the cartridge. If such a filter cartridge now hits a machine part during manufacture, or falls on the floor, the cartridge is hit or damaged in the area of its largest radial dimension. The sealing element is protected from impacts and other effects.

A far greater advantage is linked with these advantages, however, in that different shapes of cartridges can be used, provided that the upper part of the cartridge has the correct diameter at the place with the sealing element, corresponding to the aperture in the funnel base (with a smaller dimension than the largest radial dimension of the filter cartridge). While in the known instance when the filter volume is increased, the largest radial dimension of the filter cartridge is increased even more, so the sealing element must also be provided with a larger diameter, according to the invention the diameter of the sealing element may now be independent of the largest radial dimension of the filter cartridge.

4 It is also ensured that the filter cartridge is arranged below the base of the inlet funnel, so gravity operations can be used. The liquid to be purified can still run out of the inlet funnel above in a certain direction downwards through the granular treatment medium.

When the diameter or radius of the sealing element or of the opposite sealing piece, for example, of the sealing ring, is described, this information is not limited to a circular shape. Within the meaning of the invention a triangular surface also has a radial dimension.

The second feature of the invention, by means of which it is ensured that the filter cartridge is moved into the sealing ring on the inlet funnel, prevents excessive wear. When the means are configured suitably, twisting of the filter cartridge about its vertical central axis relative to the sealing ring located outside the cartridge is prevented. In this way the sealing surface acting outwards, an O-ring, or a similar sealing element is neither damaged nor destroyed.

It is also particularly advantageous when means are provided for protecting against twisting of the sealing element acting outwards with respect to the sealing ring on the inlet funnel. From this information, the skilled person will derive the teaching of not twisting the filter cartridge with its external sealing element with respect to the sealing ring located on the inlet funnel. Such means for protecting against twisting are obtained, for example, when guide elements are placed on the funnel base in which the filter cartridge must be fitted in order to thereby move it into the sealing ring on the inlet funnel. Such a movement could even be a pivoting movement. The axis of pivoting then needs- only to be established with respect to the base of the funnel. The movement of the filter cartridge is thus protected from twisting. Other means for protection from twisting can be to configure the sealing seat in the aperture of the funnel base with a projection such that twisting of the filter cartridge is excluded. It is also conceivable to have a triangular cross-section of the upper part of the cartridge in the plane in which the sealing element acting outwards is arranged. It is clear that the other sealing geometry of the second part of the pair of sealing elements must be shaped correspondingly. Thus, when the upper part of the cartridge has a triangular shape, the sealing seat must also be shaped correspondingly.

- In a preferred embodiment, it is provided that according to the invention, the means for protection from twisting of the sealing element are an upper cartridge part with a circumference rotationally non-symmetrical with respect to the central axis of the filter cartridge, and a sealing ring with a corresponding inside surface. With one example, one can think of the periphery of the upper part of the cartridge being eccentric or rotationally non-symmetrical in the plane - generally at right angles to the central axis of the filter cartridge - in which the sealing element is arranged, for example, an O-ring. Oval or polygonal periphery shapes are just as possible as a projection made from a circular plate. All these means ensure a rotationally non- symmetrical periphery of the upper part of the cartridge where the sealing element lies, with the result that, with a suitably shaped inside surface of the sealing ring, that is to say of the sealing seat, perfect sealing is possible without twisting of the upper part of the cartridge with respect to the sealing seat being possible.

It is further advantageous according to the invention when the lower part of the upper part of the cartridge facing towards the filter cartridge is approximately a truncated cone shape, and towards the top adjoins a dome, the cross-section of which has a rotationally non-symmetrical periphery. Such an upper cartridge part allows the transition from a cup filled with a treatment medium with a large radial dimension to the small radial dimension at the height of the sealing element. The truncated cone of the upper part of the cartridge also allows the arrangement of inlet holes, slits or the like for the liquid or for the outlet of air of gases if this is necessary. It must always be taken into account, however, that the liquid to be purified must flow out of the area above the sealing element towards the inside of the upper part of the cartridge.

6 The invention is explained here principally with reference to a gravity operated system. For this reason the terms "above" and "below" are used. A different arrangement is conceivable, however, with a pressure operated system, in which the central axis of the filter cartridge described can then be set at an angle or at right angles to the perpendicular. Nevertheless, hereinafter the upper part of the cartridge will be mentioned when the part facing towards the inflowing liquid is meant, and vice-versa.

The invention is further characterised in that the sealing element acting radially outwards is an O-ring retained in a flat groove, which can be brought into engagement with a sealing seat on the inside surface of the sealing ring. In a preferred embodiment, a sealing ring can be made to project downwards from the base of the inlet funnel such that the sealing seat is fitted on the inner surface of this sealing ring. This inner surface of the sealing seat can be polygonal with rounded comers or circular with a cut out so that the other sealing element of the pair of sealing elements acting radially outwards, namely the O-ring, is retained on a suitable surface, for example in a groove. When this groove is kept in a plane this O-ring, forming the sealing element, runs in said plane, which is preferably arranged perpendicular to the central axis of the filter cartridge. In the case of an O-ring the sealing seat can have a smooth surface. With this, it is particularly advantageous when a threading through area with a larger radial dimension than that of the sealing seat is provided axially below the sealing seat. The upper part of the cartridge with the O-ring retained in the groove can be easily pushed into the correct position of rotation in the threading through area, and is pulled by the moving means firstly into the sealing seat.

It is advantageous according to the invention that the moving means for the filter cartridge are provided for movement in the direction of the central axis of the filter cartridge, and comprise a fixing ring with inwardly projecting lugs, wherein the at least one lower lug can be brought into engagement with flat webs fixed onto the filter cartridge and the at least one upper lug can be brought into contact with at 7 least partially ramp-like webs fixed onto the inlet funnel. With this embodiment, the moving means for the filter cartridge act in the direction of the central axis thereof. This is done surprisingly easily by means of a fixing ring with lugs projecting radially inwards. Before obtaining the sealed engagement, there are three 5 separate parts, namely the inlet funnel, the filter cartridge and the fastening ring. If these have been adjusted correctly to one another, so that the sealing element is located in the threading through area, the moving means for the filter cartridge can be put into operation. The fixing ring then needs only to be rotated by a certain angle and the filter cartridge is pulled in the axial direction into a sealed engagement in the aperture of the funnel base. Suitable means which will be described hereinafter, allow the user to feel when the three separate parts (cartridge, fixing ring and inlet funnel) have been brought into the correct threading through positioni in which direction the fixing ring can be rotated, and when it is in its final position, guaranteeing that the two sealing elements are safely in sealed engagement.

A means for obtaining sealed engagement with the aid of rotation of the fixing ring are the lugs projecting radially inwards from the fixing ring. If, for example, the fixing ring and the ring surfaces (an oval or a triangle is also understood to be a ring in this instance) are divided into three parts (so that their function is easier to explain), the result is three parts with an angular dimension of 120. Within this 120 there is a ramp. This runs axially from a lower to an upper level over a distance which is equal to the distance between the threading through area and the sealing seat for the sealing element.

The fixing ring is circular in cross-section, as by means of its rotation pushing of the filter cartridge relative to the funnel base has to take place., This is done by means of the lugs. In a preferred embodiment, when the circle is divided into three sections, two groups of lugs are provided on both the open ends of the fixing ring One group on one end is composed of three lugs arranged at a distance of 120" from one another, and on the opposite side the arrangements are the same but with the difference that one group is rotated by 60 with respect to the other. Thus if 8 viewed in other words - axially towards the fixing ring, this embodiment shows three segments of 120', six lugs, namely alternately at an angular distance of 600 an upper one, after rotation then a lower one, after further rotation another upper one and"so forth. In the assembled state, when the central axis of the filter cartridge and also of the inlet funnel is assumed as approximately vertical, there is an upper group of lugs, and a lower group. The lower lugs are connected to the filter cartridge, the upper lugs with the inlet funnel. This engagement is by means of webs, namely on the one hand webs fixed onto the filter cartridge (for the lower lugs) and on the other hand webs fixed onto the inlet.funnel (for the upper lugs).

The one set of webs are in a plane, the other webs in the manner of a ramp. In this way the rotational movement is transformed into an axial movement.

It is particularly advantageous when according to the invention the webs fitted onto the inlet funnel are attached to the outside surface of a fixing connector coaxial to the sealing ring, and at a distance from it, fitted to the funnel base, forming a guide groove. It was explained hereinabove that in the area of the base aperture of the inlet funnel the sealing seat is provided on the inside surface of a sealing ring. The sealing ring can be fitted on the inlet funnel, projecting axially downwards, or be moulded integrally with it. The sealing ring can have an oval, polygonal or circular shape, and the diameter of the sealing ring is smaller than the largest radial dimension of the filter cartridge.

A fixing connector is fitted onto the inlet funnel coaxially with respect to this sealing ring, the radial dimension of which is larger than that of the sealing ring, but in the preferred embodiment is also smaller than that of the largest radial dimension of the filter cartridge. While the sealing ring provides the sealing function, in which there should be no effects from rotational movement, the periphery of the sealing ring follows a generally rotationally non-symmetrical path. These arrangements are different with respect to the fixing connector. This assists the moving means in axial movement of the filter cartridge into the sealing ring in that the fixing ring is rotated relative to the fixing connector. As a result, the fixing connector is circular 9 in cross-section. On the cylindrical surface of this fixing connector which is fitted coaxially to the sealing ring, and is located at a distance from the sealing ring, webs are fixed which are fixed to the inlet funnel, as the fixing connector is rigidly connected to the inlet funnel, and which form the guide groove partially configured as a ramp. The guide groove is thus formed from two webs at distance apart axially from one another. The inner webs are the lower webs of the fixing connector and serve to move the filter cartridge into sealed engagement when the fixing ring rotates in one direction. The other webs serve to pull the filter cartridge out of sealed engagement when the fixing ring is rotated in the other direction.

The respective lower (inner) web is interrupted to the extent of the length of a lug (of the fixing ring), this being on the axial lower end of the guide groove facing towards the filter cartridge. By means of this interruption an axial insert aperture is formed for the lug on the fixing ring. In order to reach the threading through position, before initialising the device according to the invention the user guides the fixing ring over its lugs into this insertion aperture. In this way the fixing ring overlaps the fixing connector axially by half the height of the sealing ring, that is to say approximately the height of the sealing seat, and somewhat less than the height of the threading through area.

In an advantageous ft-ther configuration of the invention a latching spring is fitted adjacent to the axial insertion aperture located on the lower end of the guide groove, which latching spring can be brought into latching engagement with a latching groove fitted on the inward facing end face of the lug projecting radially from the fixing ring. When initialising the device, the user should be able to feel distinctly when the fixing ring is in the correct rotational position so that the filter cartridge can be pushed through the fixing ring into the threading through position. For this purpose, the fixing ring must firstly be inserted axially a bit further into the guide groove (namely through the axial insertion aperture), and then rotated by an angle as far as a so-called changeover position, in which the filter cartridge can be inserted into the threading through position.

The axial dimension of the insert for the fixing ring in the guide groove is limited by the web which, in the manner described, is fitted on the outside surface of the fixing connector. The correct rotational position of the fixing ring, on the other hand, is produced by the latching engagement between the lug and the fixing connector. In this latching connection, the latching spring which is located at the base of the guide groove, latches in the latching groove on the lug, which is located on the end face of said lug. The end face is the surface facing radially inwards of the lug on the fixing ring.

Another preferred embodiment of the invention is characterised in that the moving means for the filter cartridge have a pivoting means which can be articulated on the funnel base and a securing bar opposite said pivoting means - with respect to a through aperture of the filter cartridge. With this embodiment, the principle of the invention is also ensured in that one sealing element is not twisted relative to the other sealing element of the pair of sealing elements (for example the O- ring against the truncated cone shaped sealing seat) in order to complete the sealed engagement. With this embodiment the sealing element acting outwards (for example, the O-ring) is brought into engagement by pivoting the filter cartridge relative to the base of the 0 funnel. For this reason, a pivoting means is articulated on the funnel base. For 20 example, a turning web, a pivot pin, or two pivot pins can be fitted on the filter cartridge such that a pivoting axle is formed which is fixed to the filter cartridge. In order that the filter cartridge is pivoted with respect to the inlet funnel in a defined manner, retaining means are fitted to the funnel base, in which the pivot pin or pivot pins or the turning web can be inserted. In this way the axis of rotation of the filter cartridge is also fixed with respect to the inlet funnel, even though the filter cartridge can be rotated. In this way, the sealing element which is located above on the filter cartridge can be moved with respect to the other sealing element which is located below on the funnel base.

In order that after the pivoting movement and obtaining the sealed engagement this sealed position can also be fixed, according to the other feature of the invention 11 described, a securing bar, for example, in the form of a snap hook, is fitted in a pivoting manner on the top of the filter cartridge. For this reason, the securing bar must lie diametrically opposite to the through aperture in the filter cartridge, the turning web and the pivots. Furthermore, a corresponding locking element must be provided in the funnel base with which the securing bar engages such that the filter cartridge is kept tightly in sealed engagement on the funnel base.

In another preferred embodiment it is advantageous according to the invention when the upper part of the cartridge, fitted with upper inlet apertures, is fitted in the funnel base and is separated from the pivotable main part of the filter cartridge with the treatment medium. Although the through aperture with a sieve is then located on the top of the filter cartridge, so that the treatment medium is kept retained in the filter cartridge, the actual inlet apertures for the liquid to be prepared are located above the pair of sealing elements, namely on the base of the inlet funnel, preferably fitted or moulded projecting upwards above the base into the funnel.

By means of the measures according to the invention, on the one hand a large degree of sealing can be obtained between the sealing elements, and they can be kept not only protected from outside mechanical interference but also protected from friction and other stresses in that no sealing element is rotated against the other. By means of the measures according to the invention a minimum movement is obtained on the sealing surfaces so that the inlet funnel remains undamaged and useful for several years.

In this way a leakage free and 100% seal between the space in the inlet funnel is ensured for the liquid to be treated on the one hand, and the space below and outside the filter cartridge and also inside the filter cartridge on the other hand. By means of the suitable treatment medium, bacteria can in this way be kept back and/or destroyed, so that germ-freeliquids can be produced.

By mounting the filter cartridge by pushing it from below upwards into the funnel 12 base, the whole filter cartridge does not have to be firstly moved past the sealing surface, as with the known systems, but only the upper part of the cartridge, which carries the sealing means, needs to be pushed through the base with the sealing seat. In this way, with sealing means which remain the same, the shape of the main part 5 of the filter cartridge in which the treatment medium is retained can be changed. For example, the radial dimension can be increased or decreased. Curved deformations and changes in the length of the cartridge can be made. The manufacturer can optionally manufacture different main cartridge parts when the upper cartridge part stays the same, and connect them to the upper part of the cartridge.

Because of suitable markings and inscriptions, the user has only to perform a simple rotation of the faing ring in order to bring a newly inserted filter cartridge into sealed engagement in the inlet funnel. In addition, by means of the latching described, the user feels when the correct rotated position has been obtained in which the sealing occurs; and when after loosening, the used filter cartridge can be removed.

With suitable height of the ramp of the guide groove, user-friendly forces with which the sealed engagement can be obtained and the cartridge removed from the sealed engagement can be used.

Further advantages, features and possibilities for application of the present invention will be evident from the following description of preferred embodiments with reference to the attached drawings. In these is shown in:

I Figure 1 cut away, the important parts of a device according to the invention in the threading through position, Figure 2 a similar view to that of Figure 1, wherein after a rotation of the fixing 30 ring by 120', the sealed position of the filter cartridge in the base of the inlet funnel is obtained, 13 Figure 3 a view of the base of a part of the filter base cut away externally along a circle, with a view towards the sealing ring on the inside and the fixing connector on the outside, Figure 4 a plan view of the upper part of the cartridge with three inlet apertures each offset by 120' to one another for the lugs on the fixing ring in the planar lower groove on the outside on the upper part of the cartridge, Figure 5 cut away, the developed view of a part of the cylindrical outside surface of the fixing connector with the guide grooves, wherein the central guide groove is shown with the ramp-shaped part, Figure 6 a cut away cross-sectional view of the wall, shown enlarged, of the fixing connector in the area of a latching spring, Figure 7 a plan view of the fixing ring with a view towards the group of upper lugs on the one hand and the other group of the lower lugs, offset by 60' thereto, Figure 8 a cross-section of the faing ring along the line VEII-VM of Figure 7, Figure 9 a plan view of a lug, when viewed from the centre of the fixing ring outwards in the direction B of Figure 7, in this case a lower lug, Figure 10 a view comparable to that of Figure 9, here according to the direction of view A, however, an upper lug, Figure 11 a plan view of the upper lug of Figure 10 in an enlarged scale, with the latching groove emphasised, Figures 12 to 14 another embodiment with pivoting means, wherein there is shown in:

Figure 12, in perspective, the inlet funnel in the base of which the upper part of the cartridge with upper inlet apertures is moulded, projecting into the volume of the inlet funnel, Figure 13 a view of the inlet funnel from the bottom, shown cut away, Figure 14 the main part of the filter cartridge with pivoting means in the form of two pins and a snap hook arranged opposite, Figures 15 to 17 show another embodiment, wherein there is shown:

14 Figure 15 a view of the inlet funnel similar to Figure 12, Figure 16 aview of the inlet funnel from below, shown cut away, similar to Figure 13, and Figure 17 another embodiment of the filter cartridge similar to Figure 14, wherein a snap hook is also located opposite the turning web.

In a collecting jug, which is not shown, a filter cartridge 2, fitted below an inlet funnel 1, is immersed - The latter is composed of a main part 3 which is filled with granular treatment medium which is not shown, and an upper part 4 of the cartridge. The main part 3 of the filter cartridge 2 is formed by side walls 6 which are approximately cylindrical, are cut off at the bottom in Figures 1 and 2, and therefore are closed by an outlet sieve which is not shown. The treatment medium is inside. The lower part 5 of the upper part 4 of the cartridge is in the shape of a truncated cone. A dome 9 follows on from the upper edge 7 of this truncated cone upwards in the direction of the central axis 8 of the whole device. Inlet apertures for the liquid to be treated can be provided in this in a manner not shown.

Figure 4 shows the plan view of the upper part 4 of the cartridge. T11e cross-section of the dome 9 with the rotationally non-symmetrical periphery 10 is evident. The thick black line indicates the 0-ring 12 projecting radially outwards out of the groove 11 as the sealing element 12 acting outwards. The 0-ring also follows a rotationally non-symmetricaI path corresponding to the cross-section of the dome 9, in the case of this exemplary embodiment approximately triangular with rounded comers, and slightly rounded lines in between. In this way, neither the dome 9 nor the 0-ring 12 are rotationally symmetrical about the central axis 8. The central crossing point in Figure 4 is the point of intersection of the central axis 8, which extends in the direction of viewing, with the plane of the paper. Outside the lower, truncated cone-shaped part 5 of the upper part 4 of the cartridge, there is connected the upper, flat web 13 which is interrupted at three places at an angular distance apart from one another of 120 by inlet apertures 14. From the cross- sectional view of Figures I and 2, the outer part of the flat, lower web 15 is evident, which with its circular shape forms, together with the upper web 13, a flat movement groove 16. The lower annular web 15 is connected via a shoulder 17 to the upper edge of the side wall 6 of the main part 3 of the filter cartridge 2.

On the base 18 of the inlet funnel 1, a sealing ring 19 (Figures 1 to 3) with a similar triangular cross-section to that of the flat groove 11 and the cross-section of the dome 9, surrounds an aperture 20 with a corresponding cross-section. The view of the funnel base 18 from below according to Figure 3 is shown in a smaller scale than the plan view of the upper part of the cartridge According to Figure 4. The 10 viewer must imagine, however, that the dimensions of Figure 3 have to be larger, wherein the sealing ring 19 would have to be approximately as large as the O-ring 12. The inside surfaces of the sealing ring 19 are best explained with reference to 15 Figure 1. Here it is shown that the sealing ring 19 projecting approximately 5 mm to 20 mm, preferably 16 mm downwards from the base 18 is configured thinner towards the filter cartridge 2 and in the upper third with somewhat thicker walls. In the thinner walled part the inside diameter of the sealing ring 19 is thus larger, and forms the threading through area 21. From here upwards, bridged over by a 20 slight cone, the inside diameter of the sealing ring 19 narrows to a dimension of a sealing seat 22, against which the O-ring 12 is pressed in sealed engagement. This position of sealed engagement is shown in Figure 2. The upper part 4 of the cartridge has been pushed upwards out of the threading through position of Figure 1 by approximately 8 mm to 10 mm into the sealed position of Figure 2, axially in 25 the direction of the central axis 8. By means of the measures for movement still to be described, the engagement of the O-ring with the sealing seat 22 is done without rotational movement, that is to say with low friction and protecting the material. A fixing connector 23 is fitted coaxially on the bottom on the base 18 of the inlet 30 funnel 1, for example fixed or moulded, at a distance from the sealing ring 19. As can be seen from the plan view in Figure 3, the fixing connector 23 is circular. On 16 its cylindrical outside surface 24, which is approximately double the height of the sealing ring 19, webs 25, 26 are fixed, arranged at a distance a apart from one another (Figure 5) and running parallel to one another, projecting radially outwards. In this way a guide groove 27 having the width a is formed. Each guide groove extends along the periphery over an angle of 120'. At ihe beginning and at the end, each groove 27 is closed by a closing wall 28, 29. The lower horizontal end of the guide groove 27 is shown in the central area to the right in the drawing of Figure 5, wherein the lower web 25 is interrupted in order to from an axial inlet aperture 30. The left-hand upper end shown in the central area. of Figure 5 with the closing wall 28, is higher by the width of the groove plus the two webs 25, 26 than the right-hand end. The ramp-shaped part, designated 31, of the guide groove 27 is located in between. Figure 6 is a cut-away sectional representation of the fixing connector 23 with its 15 outside surface 24, which in this case is identical to the base of the groove 27. In the lower and in the upper horizontal part an approximately vertical, elongate latching spring 32, which can be seen in Figure 6 in crosssection as a projection, is fitted approximately in the centre. This has to latch into a latching groove 33 (Figures 9 to 11), as will be described later. 20 In operation, there is an insertion position at I, at H (to the left thereof in Figure 5) a changeover position (for the filter cartridge), and at III a terminal and sealed position. 25 Three parts are necessary for sealing the filter cartridge with respect to the inlet funnel 2. The first part is the filter cartridge 2 which was described above. The second part is the inlet funnel 1 with its base 18 and the annular walls arranged projecting from it, namely the sealing ring 19 and the flydng connector 23, as precedingly described; and lastly the fixing ring 34 which will be described 30 hereinafter with reference to Figures 7 to 11. In cross-section, the fixing ring 34 is circular. It has on each of its two free ends three lugs 35, 36. 35 are the upper 17 lugs which form a group of three lugs 35. These can be seen in Figures 7, 8, 10 and 11. On the lower end of the fixing ring 34 there are also located three lugs 3 6, which form a group of the lower lugs 36. These lower lugs can be seen in Figures 7 to 9. Within each group, each lug is arranged at an angular distance of 120 from the adjacent one. The two groups of lugs 35 on the one hand and lugs 36 on the other hand are arranged at an angular distance of 60 from one another. For this reason all six lugs can be seen in Figure 7.

In Figure 7, if viewing in the direction of the arrow B, Figure 9 is seen, in which the inside wall of the fixing ring 34 is interrupted. The important matter here is the radial view of the lug 36, however. Like the other lugs 35, this has in the centre a vertical latching groove 33 which passes through the whole lug 35, 36. In the direction at right angles to this latching groove there is located the direction of movement of the lugs 35 and 36, and there, the lugs are chamfered. The chamfr is designated 37.

The length b of the respective lugs 35 and 36 in the direction of the periphery of the fixing ring 34 is between 5 and 20 mm, preferably 8 to 16 mm. This length b (Figure 7) is the same for all the lugs 35, 36 and somewhat smaller than the axial inlet aperture 30 in the lower web 25 of the guide groove 27 and of the inlet aperture 14 in the flat upper web 13 of the movement groove 16. The purpose of this matching of dimensions is in that the lugs are introduced into these inlet apertures 14, 30, and afterwards the fixing ring 34 can be rotated a little ftirther, whereby firstly a locking and non-positive connection of the three parts (inlet funnel, filter cartridge, and fixing ring) is produced.

In operation, it must be imagined that the fixing ring 34 with its upper lugs 35 is introduced into the inlet aperture 30 on the fixing connector 23, and according to the developed view in Figure 5, is rotated to the left until the latching groove 33 on the end face 38 of the respective lugs 35 and 36 comes into engagement with the latching spring 32. After the insertion position I (developed view of Figure 5) the 18 changeover position 11 is obtained by means of a slight rotation. The fixing ring 34 is now connected to the inlet funnel 1 by means of the lugs 35.

A new or replacement filter cartridge 2 can now be guided from below into the base of the inlet funnel 1 such that the dome 9 of the upper part 4 of the cartridge is inserted from below into the fixing ring 34 and upwards a short way into the sealing ring 19. More precisely, this goes as far as the threading through position of Figure 1 only when the lower lugs 36 of the fixing ring 34 are inserted in the inlet apertures 14 in the movement groove 16 on the upper.part 4 of the cartridge.

If the fixing ring 34 is now rotated relative to the two substantially stationary other parts, namely the inlet funnel 1 and the filter cartridge 2, the upper lugs then glide into the ramp-shaped part 31 of the guide groove 27. The lugs 35, 36 then pull the upper part 4 of the cartridge over the inner webs 25 and 13 in the direction of the central axis 8 upwards out of the threading through position of Figure 1 into the sealed position of Figure 2. The O-ring 12 is then pressed into the sealing seat 22.

If the fixing ring 34 is then later rotated in the opposite direction, the lugs 35 and - 36 then press the upper part 4 of the cartridge over the outer webs 26 and 15 out of the sealing seat in Figure 2 again, until the changeover position H (Figure 5) for changing the filter cartridge is reached again. It can then be removed and replaced with a new one.

Another embodiment of the device is shown in Figures 12 to 17. Like parts are 25 desianated with like references, except the reference numerals for the embodiment CP according to Figures 12,and 14 are additionally referred to with a and with the embodiment according to Figures 15 and 17 additionally with b.

Both the filter cartridges 2a and 2b are shown in Figures 14 and 17 with their main part 3a and respectively 3b. In the upper sieve area, the main part 3a and 3b carries an O-ring 12a and respectively 12b as a radially acting sealing element. This must 19 be brought into sealed pressing engagement with the sealing seat 22a and respectively 22b. This is obtained with both embodiments by means of a pivoting element. The upper part 4a and 4b is in each case moulded onto the base 18a and respectively 1 8b.

At the height of the O-ring 12a there is a box 39a on one end of which two pins 40a project such that a straight pivoting axle is formed. A tiltable and spring-pre tensioned snap hook 41a, respectively 41b, is fitted on the side opposite the pin 40a with respect to the O-ring 12.

In the embodiment of Figure 17, the pivoting axle is obtained by means of a turning web 42b, which also has a snap hook 41b opposite to it.

Cut-outs 43a, 43b are provided on the base 18a, l8b of the inlet ftmel la, lb such that on the one hand the pins 40a can be introduced into these cut-outs 43a, and respectively the turning web 42b introduced into the cut-outs 43b, and retained there. If the filter cartridge 2a, 2b is pivoted in the direction of the arrow 43, the snap hook 41a lastly goes into the cut out bar 44a, and the snap hook 41b into the cut out bar 44b, in which the snap hook comes into engagement with the bar such that the O-ring 12a, 12b is pressed tightly against the sealing seat 22a, 22b. By pressing on the loose end 45a, 45b of the snap hook 41a, 41b, the main part 3a, 3b of the filter cartridge can be released again and removed.

Claims

1 Device for preparing liquids with an inlet funnel (1) with a base aperture (20) which has an inside edge (19), and with a filter cartridge (2) which is sealed by means of a sealing element (12) against the inside edge (19) and which is provided with an upper cartridge part (4) with inlet apertures and an outlet sieve connected by means of side walls (6), between which a treatment medium is retained, characterised in that the sealing element (12) acting radially outwards is fitted to a periphery of the upper part (4) of the cartridge, and has smaller radial dimensions than the largest radial dimension of the filter cartridge (2), and in that means (27, 34, 16) are provided for moving the filter cartridge (2) in the inside edge (19) on the base aperture (20) of the'inlet funnel (1).

2. Device according to claim 1, characterised in that the radial dimension of the sealing element (12) is approximately 5% to 80%, preferably approximately 20% to 60%, and particularly preferably approximately 30% to 50% smaller than the largest radial dimension of the filter cartridge (2).

3. Device according to claim I or 2, characterised in that means (4, 9, 19) are provided for protecting against twisting of the sealing element (12) acting outwards with respect to the inside edge (19) on the base aperture (20) of the inlet funnel (1).

4. Device according to one of claims I to 3, characterised in that means (4, 9, 19) for protecting against twisting of the sealing element (12) are an upper cartridge part (4) with a rotationaBy non-symmetrical periphery with respect to the central axis (8) of the filter cartridge (2) and an inside edge (19) of the base aperture (20) with a corresponding periphery.

I 21

5. Device according to one of claims I to 4, characterised in that the lower part (5) of the upper part (4) of the cartridge facing towards the filter cartridge (2) is approximately a truncated cone shape, and towards the top adjoins a dome (9), the cross-section of which has a rotationally non symmetrical periphery.

6. Device according to one of claims 1 to 5, characterised in that the sealing element (12) acting radially outwards is an O-ring (12) retained in a flat groove (11), which can be brought into engagement against a sealing seat (22) on the inside surface of the inside edge (19) on the base aperture (20) of the inlet funnel (1).

7. Device according to one of claims 1 to 6, characterised in that the inside edge (19) on the base aperture (20) of the inlet funnel (1) is configured as an inside surface (21, 22) of a sealing ring (12) connected in a sealing manner to the base (18) of the inlet ftinnel (1).

8. Device according to one of claims 1 to 7, characterised in that the means (34 -36) for moving the filter cartridge (2) are provided for movement in the direction of its central axis (8) and are a fixing ring (34) provided with lugs (35, 36) projecting inwards, wherein the at least one lower lug (36) can be brought into engagement with flat webs (13, 15) fixed onto the filter cartridge (2) and the at least one upper lug (35) can be brought into engagement with at least partially ramp-like webs (25, 26) fixed onto the inlet funnel (1).

9. Device according to one of claims I to 8, characterised in that the webs (25, 26) fixed on the inlet funnel (1) are attached to the outside surface (24) of a fixing connector (23) coaxial to the sealing ring (19), and at a distance from it, fitted to the funnel base (18), forming a guide groove (27, 31).

22

10. Device according to one of claims 1 to 9, characterised in that a latching spring (32) is fitted adjacent to an axial insertion aperture (30) located on the lower end of the guide groove (32), which latching spring can be brought into latching engagement with a latching groove (33) fitted on the inward facing end face (38) of the lug (35) projecting radially from the fixing ring (34).

11. Device according to claim 1 or 2, characterised in that the moving means (27, 34, 16) for the filter cartridge (2a, 2b).are provided with a pivoting means (40a, 42b) which can be articulated on the funnel base (18a, l8b) and a securing bar (41a, 41b) opposite said pivoting means with respect to a through aperture of the filter cartridge (2a, 2b).

12. Device according to one of claims 1, 2 and 11, characterised in that the upper Part (4a, 4b) of the cartridge with upper inlet apertures is fitted in the funnel base (18a, l8b) and is separated from the pivotable main part (3a, 3b) of the filter cartridge (2a, 2b) with the treatment medium.

13. Filter cartridge suitable for connection with a retaining part (1), in particular for sealing connection in the base aperture (20) of an inlet funnel (1), with sealing elements (12), with an upper cartridge part (4) with inlet apertures and with a main part (3, 3a, 3b) which has an outlet sieve connected by means of side walls (6), wherein between the upper part (4) of the cartridge and the outlet sieve, a treatment medium is retained, characterised in that one of the sealing elements (12) is arranged on the periphery of the upper part (4) of the cartridge, located at a pre-determined height, which has a smaller radial dimension than the largest radial dimension of the filter cartridge (2), and in that means (27, 34, 16) are provided for moving the filter cartridge (2) relative to the retaining part (1).

I 23

14. Filter cartridge according to claim 13, characterised in that the radial dimension of the sealing element (12) is approximately 5% to 80%, preferably approximately 20% to 60%, and particularly preferably approximately 30% to 40% smaller than the largest radial dimension of the filter cartridge (2).

15. Filter cartridge according to claim 13 or 14, characterised in that means (4, 9, 19) are provided for protecting the sealing element (12), acting outwards, from twisting with respect to the retaining part (1).

M. Filter cartridge according to one of claims 13 to 15, characterised in that the upper part (4) of the cartridge has at least partially a rotationally non symmetrical periphery in order to protect the sealing element (12) from twisting.

17. Filter cartridge according to one of claims 13 to 16, characterised in that the lower part (5) of the upper part (4) of the cartridge facing towards the filter cartridge (2) is approximately a truncated cone shape, and towards the top adjoins a dome (9), the cross-section of which has a rotationally non-symmetrical periphery.

18. Filter cartridge according to one of claims 13 to 17, characterised in that the sealing element (12) acting radially outwards is an O-ring (12) retained in a flat groove (11).

19. Filter cartridge according to one of claims 13 to 18, characterised in that the means (34 -36) for moving the filter cartridge (2) are provided for movement in the direction of its central axis (8) and are a fixing ring (34) provided with lugs (35, 36) projecting inwards, wherein the at least one lower lug (36) can be brought into engagement with flat webs (13, 15) fixed onto the filter cartridge (2).

24

20. Filter cartridge according to one of claims 13 to 19, characterised in that a latching groove (33) is fitted onto the end face (38), facing inwards, of the lug (35) projecting radially from the fixing ring (34).

21. Filter cartridge according to one of claims 13 to 20, characterised in that the filter cartridge (2a, 2b) is provided on its insertion end with a pivoting means (40a, 42b) and a securing bar (41a, 41b) lying opposite said pivoting means with respect to a through aperture of the filter cartridge (2a, 2b).

22. Filter cartridge according to one of claims 13 to 21, characterised in that the upper part (4a, 4b) of the cartridge having the upper inlet apertures is fitted in the base (18a, 18b) of the ft=el and is separated from the pivotable main part (3a, 3b) of the filter cartridge (2a, 2b) with the treatment medium.

I I

2 3. Device for treating liquids, comprising: an inlet funnel having an outlet with a sealing seat; a filter cartridge having a main part containing a treatment medium and an upper part insertable into the outlet of the inlet funnel and having an outwardly-acting sealing element for forming a seal with the sealing seat, wherein the sealing element has a smaller diameter than the maximum diameter of the filter cartridge; and means for advancing the upper part in the outlet to a final sealing position.

24. Filter cartridge comprising:

a main part containing a treatment medium; and an upper part insertable into an outlet of an inlet ftmel and having an outwardly-acting sealing element capable of forming a seal with a sealing seat of the outlet; wherein the sealing element has a smaller diameter than the maximum diameter of the filter cartridge.

25. Filter cartridge assembly comprising a filter cartridge in accordance with claim 24 and means for advancing the upper part in the outlet to a final sealing position.

26. Device for treating liquids, comprising: an inlet funnel having an outlet with a sealing seat and a filter cartridge upper part positioned at the outlet; and a filter cartridge main part containing a treatment medium and having a sealing element for forming a seal with the sealing seat, the sealing element having a smaller diameter than the maximum diameter of the filter cartridge main part; wherein the filter cartridge main part is pivotably connected to the inlet funnel so as to be pivotable from an open unsealed position to a closed sealed position.

27. Filter cartridge main part for forming a filter cartridge with a filter cartridge upper part positioned at an outlet of an inlet funnel, wherein:

the filter cartridge main part contains a treatment medium and has a sealing element capable of forming a seal with a sealing seat of the outlet; 26 the sealing element has a smaller diameter than the maximum diameter of the filter cartridge main part, and the filter cartridge main part includes pivoting means for pivotably connecting the filter cartridge main part to the inlet ft=el so as to be pivotable from an open 5 unsealed position to a closed sealed position.

28. Device for treating liquids, substantially as herein described with reference to, or with reference to and as illustrated in, Figs. I -11, Figs. 12-14 or Figs. 15-17 of the accompanying drawings. 10

29. Filter cartridge substantially as herein described with reference to, or with reference to and as illustrated in, Figs. 1, 2 and 4 of the accompanying drawings.

30. Filter cartridge assembly substantially as herein described with reference to, or 15 with reference to and as illustrated in, Figs. I - I I of the accompanying drawings -

31. Filter cartridge main part substantially as herein described with reference to, or with reference to and as illustrated in, Fig. 14 or Fig. 17 of the accompanying drawings. 20 I