Abstract:
The invention relates to a filter cartridge ( 1 ), especially a suction filter cartridge, which is provided, in the outlet opening ( 20 ), with an inward-pointing, peripheral snap-on rim ( 22 ) which can be folded from a first lower snap position into a second upper snap position and vice versa. The invention also relates to a seat element ( 30 ) for such a filter cartridge, comprising a connection sleeve ( 33 ) which engages with the outlet opening ( 20 ) of the filter cartridge ( 1 ). Said connecting sleeve ( 33 ) comprises at least one actuator which displaces, when the filter cartridge ( 1 ) is placed on the rim, the snap-on rim from a first lower snap position to the second upper snap-on rim from a first lower snap position to the second upper snap positioning which the snap-on rim rests against the connecting sleeve ( 33 ) in a sealing and clamping manner.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a filter cartridge, in particular a suction filter cartridge, according to the preamble of claim  1 . The invention also comprises a seat element for such a filter cartridge. The inlet area and the outlet opening of the filter cartridge are arranged at the bottom area of the filter cartridge, which also includes a lateral inlet or outlet in a lower section of the inflow and outflow chamber adjacent to the bottom. 
     2. Description of Related Art 
     Suction filter cartridges are used in water vessels of automatic drink dispensers, e.g., for hot drinks, provided with a suction pump, such as e.g., coffee makers etc. The inlet and outlet openings of the suction filter cartridge are located in the bottom area of the otherwise completely enclosed cartridge housing. A seat element is arranged in the water vessel of the device, adjusted to the outlet opening, which may be a separate component or be formed at a water vessel. This seat element has an outlet opening as well, through which the filtered water can flow out of the water vessel. The seat element serves to accept the suction filter cartridge inserted into this seat element. 
     Due to the fact that the outlet opening of the water vessel is connected to the suction pump of the device, the water to be filtered is suctioned out of the water vessel, passes the filter medium or filter media in the cartridge, and reaches the outlet opening in a filtered state. 
     Due to the fact that the suction filter cartridge is arranged inside the water vessel of the device the filter cartridge floats when the water vessel is filled. In order to prevent floating and thus a separation of the filter cartridge from the outlet opening of the seat element of the water vessel special fastening means are provided. According to a known solution the suction filter cartridge is screwed onto the seat element. Here it is disadvantageous that suction filter cartridges with an asymmetrical filter housing cannot be screwed into narrow water vessels. Additionally, in deep and narrow water vessels tools are necessary to screw in the cartridge. 
     Another resolution provides for the suction filter cartridge to be placed onto the seat element and to turn over a clamping element after the insertion in order to fix the suction filter cartridge in its position. 
     From WO 99/01220 a suction filter cartridge is known, in which the water inlet opening is arranged at the bottom and a pass for water through the filter media is provided in the up-current. Furthermore, a downspout is provided for guiding the water downwards to an extraction connector of the water vessel located at the bottom. Here, the mixture of filter means comprising activated carbon and ion exchangers are floated during operation, counteracting any compression of the filter bed. 
     The downspout is arranged centrally inside the suction filter cartridge, so that the bottom connector of the suction filter cartridge can also occur centrally. Here, the inlet opening is arranged circularly in the suction filter cartridge. 
     An axial closing element is necessary to seal the outlet channel from the inlet channel. 
     The suction filter cartridge comprises at its bottom fixing elements, by which it can be connected to a seat element. Additionally it is necessary, though, that the suction filter cartridge is supported on the lid of the water vessel in order to prevent floating of the suction filter cartridge in a filled water vessel. Here, it may be necessary in deep water vessels to extend the suction filter cartridge at the top, e.g. by a rod. 
     Such additional securing elements are frequently not arranged correctly, thus the tight seat on the seat element is not ensured. 
     BRIEF SUMMARY OF THE INVENTION 
     Therefore, the object of the invention is to provide a filter cartridge, in particular a suction filter cartridge, which goes without any additional securing elements, can be inserted in a simple manner, and ensures a reliable seal in the area of the outlet opening. 
     This object is attained in a filter cartridge, in which a snap-on rim is provided in the outlet opening, pointing inwardly, which can be turned down from a first lower snap position into an upper second snap position and vice versa. 
     The corresponding seat element is characterized by a connecting sleeve engaging the outlet opening of the filter cartridge, having at least one actuator, which moves the snap-on rim from the first lower snap position into the second upper snap position when placed onto the filter cartridge, in which the snap-on rim contacts the connecting sleeve in a sealing and clamping manner. 
     Preferably the actuator is a circular shoulder arranged at the connecting sleeve. 
     The filter cartridge with the snap-on rim situated in the lower snap position is placed onto the seat element from the top and pressed downward until the snap-on rim turns upwards and hereby engages the connecting sleeve of the seat element. The seat element is adjusted to the snap-on rim such that with a turned-over snap-on rim the filter cartridge contacts the connecting sleeve in a sealing manner and is fixed. The turn-over signals to the operator that the filter cartridge has taken its predetermined sealing position. This prevents a faulty positioning by the operator. 
     In order to remove the filter cartridge it is only pulled out upwards, which turns the snap-on rim back into its lower snap position. 
     Preferably the outlet opening is provided with an outlet sleeve, with a snap-on rim being linked to its lower end. The snap-on rim may be linked via a film link. 
     The snap-on rim is preferably a flat edge strip extending radially inward. 
     The edge strip is preferably embodied as a ring. 
     The snap-on rim settles in two stable positions, namely a lower position and an upper one. The intermediate position of the snap-on rim is an unstable position, from which based on its tension it automatically turns into one or the other position. The snap-on rim advantageously comprises an elastic plastic. 
     By the turn-over process of the snap-on rim radial forces act upon the outlet sleeve, which may lead to a widening and perhaps to a reduction of the clamping forces in the upper second snap position. Therefore, it is advantageous for the outlet sleeve to be surrounded by a circular stabilizer. 
     Advantageously the circular stabilizer is provided with an angled collar protruding into the outlet opening, which the snap-on rim contacts in the first lower snap position. This ensures a defined original position for the snap-on rim. 
     Preferably the circular stabilizer is arranged rotary at the outlet sleeve. The rotation of the circular stabilizer allows to provide an bypass adjustable in its cross-section, which connects the inlet area to the outlet opening. 
     The adjustable bypass is preferably sized such that not the entire crude water immediately flows from the inlet opening into the outlet opening. Preferably the bypass is designed such that no more than 50% of the crude water can be diverted to the outlet opening. 
     In particular, this is possible when the inlet area of the filter cartridge surrounds the outlet sleeve in a circular fashion. 
     According to a first variant the outlet sleeve is provided with at least one first opening. The circular stabilizer is provided with a cylindrical section contacting the outlet sleeve, at which preferably a closing element or in which preferably at least one second opening is provided, which can be aligned to the first opening. In this case the first and second opening(s) combined form the bypass opening(s). 
     By rotating the circular stabilizer the cross-section of the first opening of the outlet sleeve can be adjusted such that the added amount of the untreated crude water can be added to the water treated by the filter means in the filter cartridge, adjusted in a controlled manner. Using such a bypass the performance of the filter cartridge can be adjusted to the water quality such that the water best for the aroma and best for the automatic drink dispensers can be provided. Depending on the water quality found on the location of the automatic drink dispensers and the selected coffee brand entirely decarbonized water may not be optimal for the development of the aroma, and even the machine parts may be damaged. When decarbonization is not adjusted, in the worst case scenario, corrosion of the metal components may develop. Then the consequences are high maintenance and repair costs. 
     Additionally, the integrated bypass increases the capacity of the filter cartridge. When based on the water quality less performance is necessary, it is adjustable and the filter cartridge softens to the same level for a longer period of time. 
     Preferably the second opening of the circular stabilizer has a size that is greater than or equal to a size of the first opening of the outlet sleeve. 
     The circular stabilizer preferably contacts the outlet sleeve in a sealing manner. This prevents that in closed first openings unintentionally crude water can enter the outlet opening, in particular through the second openings of the circular stabilizer between the circular stabilizer and the outlet sleeve. 
     A second variant provides at least one bypass opening in the bottom wall of the outflow chamber. The bypass opening is preferably closed by a closing element arranged at the circular stabilizer, with the crude water amounts flowing through the bypass opening can be adjusted by way of rotating the circular stabilizers. 
     The closing element may be an arc-shaped collar arranged at a circular stabilizer, which preferably contacts the underside of the bottom wall of the outflow chamber in a sealing manner. 
     Instead of a closing element, similar to the first variant, the collar may be provided with one or more second opening(s), which can be aligned to the opening(s) in the bottom wall of the outflow chamber. 
     Different from the first variant, the crude water does not reach the outlet sleeve immediately, rather it is guided into the interior of the outflow chamber, allowing this crude water also to be filtered. 
     The extent crude water is guided into the interior chamber of the outflow chamber can be defined by the length of the riser surrounding a bypass opening. The lower section of the outflow chamber is therefore jointly used by the already filtered water and by the crude water introduced via the bypass opening. 
     The jointly used area may be provided with a fill of activated carbon for dechlorinizing the bypass water. Depending on the type and form of the fill material a separating layer may be provided on the fill, comprising a fleece, for example, in order to prevent any mixing with the filter means, arranged perhaps thereabove, e.g., made from an ion exchanging material. 
     This jointly used area inside the down-current chamber may also be separated by an intermediate floor not penetrable by liquids. In the chamber formed between the bottom and the intermediate floor a filter medium may be arranged, particularly an activated carbon fleece. 
     Both the up-current chamber as well as the down-current chamber may be provided with at least one filter means. It has shown advantageous for the up-current chamber to be provided with an fluidized bed and the down-current chamber with a packed bed. The advantage of the equipment of both filter chambers with filter means lies the fact that the risers and/or downspouts of prior art, extending over the entire height of the suction filter cartridge, can be omitted. The fluidized bed in the up-current chamber causes only a slight loss of pressure. 
     Advantageously the outlet sleeve and/or the circular stabilizer, are provided, preferably below the first opening, with at least one sealing bead extending around the perimeter such that any unintended bypass is prevented. 
     In a simple embodiment the seat element may be provided with a base plate, at which the connecting sleeve is arranged. 
     At least one spacer is arranged on the base plate in order to allow or to facilitate the inflow of crude water into the filter cartridge. When inserting the filter cartridge it rests to the spacer. 
     Furthermore, at least one positioning element may be provided on the base plate in order to facilitate the insertion of the filter cartridge on the seat element. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the following, exemplary embodiments of the invention are explained in greater detail using the drawings. A suction filter cartridge is described as an example for the filter cartridge according to the invention. It is shown: 
         FIG. 1  a perspective view of a suction filter cartridge having an attached seat element, 
         FIG. 2   a  a vertical cross-section through  FIG. 1  showing a filter cartridge with an attached seat element, 
         FIG. 2   b  an enlarged representation of the outlet area of the suction filter cartridge shown in  FIG. 2   a,    
         FIG. 3  a vertical cross-section through the suction filter cartridge shown in  FIGS. 1 and 2   a, b , without a seat element, 
         FIG. 4  an enlarged perspective representation of the lower section of the suction filter cartridge shown in  FIGS. 1 through 3 , partially in a cross-section, 
         FIG. 5  a perspective top onto of seat element shown in  FIGS. 1 and 2   a, b,    
         FIG. 6  an enlarged cross-section of the lower area of the suction filter cartridge according to another embodiment, 
         FIG. 7  a perspective bottom view to the outlet opening of the suction filter cartridge. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In  FIG. 1  a suction filter cartridge  1  is shown in a side view. The suction filter cartridge  1  has a central housing part  2 , which has the down-current chamber  2   a , and a housing part  3  laterally mounted to the housing part  2 . The off-set arrangement of the housing parts  2  and  3  serves the purpose that the up-current and down-current chambers can be embodied with a large volume at a narrow width of the water vessel. 
     The suction filter cartridge  1  is supported on a seat element  30 , which is located in or at the outlet opening of the water vessel (not shown). The suction pump, not shown either, is connected to the outlet opening. During operation water is suctioned out of the water vessel into the suction filter cartridge  1  and removed through the outlet opening. The seat element  30  may also be an integral component of the water vessel. The seat element  30  has a base plate  31 , on which position elements  32  are arranged in an annular manner, which will be described in greater detail in the following. 
       FIG. 2   a, b  show a vertical cross-section through the suction filter cartridge  1  with an attached seat element  30 . In the central housing part  2  there is a down-current chamber  2   a , which may be filled with a packed bed made from a filter material. An up-current chamber  3   a  is located in the attached housing part  3  with the bottom wall  3   b , which may comprise a fluidized bed made from a filter material. This up-current chamber  3   a  is separated by a vertically arranged separating wall  6  from the down-current chamber  2   a . In the embodiment shown here the separating wall  6  is a component of the circumferential wall of the down-current insert  9 , which is additionally provided with a bottom wall  7  with a centrally arranged floor grid  8 . Both chambers  2   a ,  3   a  are connected to a connection opening  5  via a connection chamber  4  arranged in the upper area of the suction filter cartridge  1 . 
     The inlet area  10  is arranged in the lower section of the suction filter cartridge  1 , embodied as a circular channel  12 . Said circular channel  12  is formed by a circular wall  11 , protruding downwards from the central and attached housing  2 ,  3 , and an outlet sleeve  21  surrounding the outlet opening  20  of the down-current chamber  2   a . The circular chamber  12  mouths in empties into the up-current chamber  3   a  via a grid  13  in the bottom wall  3   b . The grid  13  is provided with the inlet openings  14 . 
     The outlet sleeve  21  is provided with first openings  25 , connecting the inlet area  10  and/or the circular channel  12  with the outlet opening  20 . This represents slot-shaped openings  25 , arranged distributed over a section of the perimeter of the outlet sleeve  21 . At the lower end of the outlet sleeve  21   a  closed circular snap-on rim  22  is linked via a film link  23 , which protrudes radially inward into the outlet opening  20 . At the exterior wall of the outlet sleeve  21  a circular stabilizer  50  is arranged, having a cylindrical section  51  and a collar  52 , inclined at an angle towards the inside. In the cylindrical section  51  second openings  53  are arranged (also see  FIG. 4 ), which can be aligned by rotating the circular stabilizer  50  to the first openings  25 . The first and second openings  25 ,  53  together form the bypass openings. 
     The seat element  30  is provided with a connecting sleeve  33  surrounding its outlet opening  37 , comprising a lower section  33   a  and a section  33   b  with its diameter being reduced. A circular shoulder  35 , pointing upwards in an inclined fashion, is arranged between the two sections  33   a ,  33   b , forming the actuator for the snap-on rim  22 . Bars  34  span over the outlet opening  37  at the upper section  33   b.    
     When placing the suction filter cartridge  1  onto the seat element  30  the snap-on rim  22  is grasped by the circular shoulder  35  and turned upward into the second snap position, in which it contacts the section  33   b  of the connecting sleeve  33  in a sealing and clamping manner, thus fixing the suction filter cartridge  1 . The exterior diameter of section  33   b  is slightly larger than the interior diameter of the snap-on rim  22  in its second snap position, in order for the desired clamping forces to develop. Additional closing elements are unnecessary. 
     When the water vessel is filled and/or the suction pump is switched off the suction filter cartridge cannot float. Additional fixing or fastening means for the suction filter cartridge  1  are therefore not necessary. 
     The seat element  30  is provided with positioning elements  32 , comprising the towering centering elements  32   a  and the spacers  32   b . The circular wall  11  of the suction filter cartridge  1  is supported on the spacers so that crude water can flow into the suction filter cartridge  1  through the intermediate space between the base plate  31  and the circular wall  11 . This way, inlet channels  36  are formed (see  FIG. 2   b ) between the positioning elements  32 . 
     In  FIG. 3  the suction filter cartridge  1  is shown with the snap-on rim  22  in its lower snap position, in which the snap-on rim  22  is supported on the collar  52  of the circular stabilizer  50 . In order to seal the gap between the circular stabilizer  50  and the outlet sleeve  21  the circular stabilizer  50  is provided with an encircling sealing bead  24  at the cylindrical section  51 . 
     In  FIG. 4  the lower section of the suction filter cartridge  1  is shown enlarged and in a perspective. The rotary circular stabilizer  50  is provided with second openings  53 , which are located opposite to the first openings  25 . By rotating the circular stabilizer  50  these second openings  53  can be aligned to the first openings  25 . Depending on the level of overlapping of the openings  25 ,  53  more or less crude water can be guided from the inlet area  10  directly into the outlet opening  20 . 
     The seat element  30  is shown in a perspective in  FIG. 5 . It is discernible that the connecting sleeve  33  is surrounded by an annulus of positioning elements  32 . 
       FIG. 6  shows the lower section of a suction filter cartridge  1  according to another exemplary embodiment relating to the bypass openings. Differently from the previously described embodiments, here at least one bypass opening  26 , preferably embodied as bores in the bottom wall  21   a , connect the outlet sleeve  21  with the circular wall  11 . This bottom wall  21   a  is also shown in  FIGS. 2   a ,  2   b ,  3 , and  4 , with the bottom wall  7  of the down-current insert  9  resting on said bottom wall  21   a . In the embodiment shown in  FIG. 6  the bottom wall  7  is omitted so that the bottom wall  21   a  closes the down-current chamber  2   a  at the bottom. The crude water flowing into the circular channel  12  through the bypass openings  26 , with in  FIG. 6  only one bypass opening  26  being shown, is not guided immediately into the outlet opening  37  but into the interior of the down-current chamber  2   a , provided at a distance from the bottom wall  21   a  with an intermediate floor  7   a  permeable by liquids. The permeability of the intermediate floor  7   a  is limited to a central area  7 ′. By said intermediate floor  7   a  another chamber  60  is separated in the lower section of the down-current chamber  2   a . Inside said chamber  60  risers  27  are arranged bypassing the bypass openings  26 . The crude water is guided upwards through these risers  27  and deflected by the not permeably circular area  7 ″ of the intermediate floor  7   a . In chamber  60  a filter material may be arranged, for example a fleece, which is held by needles  15 . 
     In order to close and/or release the bypass openings  26 , the circular stabilizer  50  is provided with a closing element  54  at the upper edge, which is formed to the circular stabilizer  50 . In order to prevent unintentional bypassing this closing element  54  contacts the underside of the bottom wall  21   a  in a sealing manner. The closing element  54  comprises an arc-shaped collar, as discernible from  FIG. 7 . By rotating the circular stabilizers  50  the bypass openings  26  may be released or closed. 
     In  FIG. 7  a perspective bottom view to the outlet opening  20  of the suction filter cartridge  1  is shown. The collar  52  is provided with markings  55  showing the operator the present position of the circular stabilizer  50 . The circular stabilizer  50  may be rotated by the operator via corrugation, so that he/she can adjust the desired amount of liquids that shall be deflected into the outlet opening  20 . Additionally the closing element  54  is shown as an arc-shaped collar of the circular stabilizer  50 . 
     LIST OF REFERENCE CHARACTERS 
     
         
         
           
               1  Suction filter cartridge 
               2  Central housing part 
               2   a  Down-current chamber 
               3  Attached housing part 
               3   a  Up-current chamber 
               3   b  Bottom wall 
               4  Connecting chamber 
               5  Connecting openings 
               6  Separating wall 
               7  Bottom wall 
               7 ′ Permeable section 
               7 ″ Impermeable section 
               7   a  Intermediate floor 
               8  Bottom grid 
               9  Down-current insert 
               10  Inlet area 
               11  Circular wall 
               12  Circular channel 
               13  Grid 
               14  Inlet opening 
               15  Needles 
               20  Outlet opening 
               21   a  Bottom wall 
               21  Outlet sleeve 
               22  snap-on rim 
               23  Film link 
               24  Sealing bead 
               25  First opening 
               26  Bypass opening 
               27  Riser 
               30  Seat element 
               31  Base plate 
               32  Positioning element 
               32   a  Centering element 
               32   b  Spacers 
               33  Connecting sleeve 
               33   a  Lower section 
               33   b  Upper section 
               34  Bar 
               35  Circular shoulder 
               36  Inlet channel 
               37  Outlet opening 
               50  Circular stabilizer 
               51  Cylindrical section 
               52  Collar 
               53  Second openings 
               54  Closing element 
               55  Marking 
               60  Chamber 
           
         
       
    
     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.