Abstract:
A connecting structure connects a filter housing to a filter housing retaining structure. The connecting structure conducts a liquid that is to be cleaned to the filter housing and discharges a purified liquid. The connecting structure includes a filter housing cover that connects to the filter housing and that receives a filter medium. The filter housing cover has attachment elements that connect to corresponding attachment elements of the filter housing retaining structure to establish an exchange of fluids between the filter housing retaining structure and the filter housing. Filter housing cover guides are on opposing sides of the filter housing cover; and guides on the filter housing retaining structure engage the filter housing cover guides when connecting the attachment elements of the filter housing cover with the attachment elements of the filter housing retaining structure to support and linearly guide the filter housing cover during the connection process.

Description:
BACKGROUND 
     1. Field of the Invention 
       [0001]    The present application relates to a connecting structure for connecting a filter housing to a filter housing retaining structure, to a cleaning system having this type of connecting structure and filter housing retaining structure, to a filter housing cover for a filter housing and to a method for connecting a filter housing cover to a filter housing retaining structure. 
       2. Description of the Related Art 
       [0002]    Pure water is usually required to supply laboratory devices (e.g. autoclaves, rinsing machines, water baths, etc.). This water should be as free as possible of ions, organic components, particles and other possible impurities so as not to influence the functionality of the laboratory devices or subsequently cause contaminations. 
         [0003]    Water is likewise required for the preparation of buffers and cell culture media. The prepared water must have a high degree of purity so that it does not negatively influence the growth of the cell cultures. 
         [0004]    Water treatment systems that remove the various impurities from the water are used to prepare pure water or ultrapure water for the applications described above. 
         [0005]    In this system, water is conducted through a filter housing containing a filter medium, such as activated carbon and/or resin, which filters the undesirable impurities out of the water. 
         [0006]    For this purpose, the filter housing is coupled with a housing of the water treatment system so that it can be supplied via the housing of the water treatment device which contains the water to be cleaned or which is connected to a corresponding water supply line. The purified water then flows back into the collection tank for the purified water within the water treatment device. 
         [0007]    However, coupling the filter housing with the housing of the water treatment device has proved to be problematic in the prior art. 
         [0008]    For example, a support structure for a filter housing is known from European patent EP 1 542 782 B1. The support structure has two support arms which face each other. Each of the opposing sides of the support arms is provided with a recess that extends in a direction for connecting the filter housing to the support structure. The recesses taper toward the support structure. A latching lug is located on the lower surface of the recess and protrudes into said recess. The filter housing has a cover, the lateral surfaces of which can each be inserted into the recesses. To accomplish this, the lateral surfaces of the cover are first moved in a tilted position along the upper surface of the recesses toward the support structure. As soon as the user senses resistance, which is intended to correspond to the connected position, the user must tilt the cover and the filter housing downward so that a recess in each lateral surface of the cover latches with the latching lug in the recess of the support arms. 
         [0009]    However, this design from the prior art has the disadvantage that the lateral surfaces of the cover must initially be fitted precisely into the region between the latching lug and the inclined upper surface of the two recesses in the support arms. This requires that the cover and the filter housing be held in the precisely tilted position, since the latching lug would otherwise block a displacement to the connected position in the recesses. 
         [0010]    Consequently, the problem addressed by the present invention is that of providing a connecting structure for connecting a filter housing with a filter housing retaining structure, which permits a simple and reliable connection. 
       SUMMARY 
       [0011]    This problem is solved according to one aspect of the present application by a connecting structure for connecting a filter housing to a filter housing retaining structure, said structure being designed to conduct a liquid that is to be cleaned to the filter housing and to discharge the purified liquid, wherein the structure comprises:
       a filter housing cover that can be connected to the filter housing, which is designed to receive a filter medium, comprising:
           at least two filter housing cover attachment elements that can be connected to corresponding filter housing retaining structure attachment elements in the filter housing retaining structure in order to establish an exchange of fluids between the filter housing retaining structure and the filter housing;   at least two filter housing cover guide members, which are provided on substantially opposing sides of the filter housing cover; and   
           guide members, which are arranged on the filter housing retaining structure and are configured such that the filter housing cover guide members engage with the guide members during the process of connecting the attachment elements of the filter housing cover with the attachment elements of the filter housing retaining structure in order to support and guide the filter housing cover during the connection process and to mount it such that it can be displaced in a linear connecting direction.       
 
         [0016]    The term “linear” in this instance also includes a connecting direction that is substantially linear. “Substantially” is understood to include a minor deviation owing to expansion, for example. 
         [0017]    The term “connectable” refers both to reversible connections between the attachment elements of the filter housing retaining structure and the attachment elements of the filter housing cover and to non-reversible connections between the filter housing cover and the filter housing. The connection between the filter housing cover and the filter housing can also be configured as a non-reversible connection, though. 
         [0018]    The guide members permit the filter housing cover, on which the filter housing cover attachment elements are located, to be displaced toward the attachment elements of the filter housing retaining structure in a straight-line movement. The filter housing cover is supported throughout the connection process and is retained in a predetermined position so that the attachment elements of the filter housing cover can be reliably connected to the attachment elements of the filter housing retaining structure. In other words, the attachment elements of the filter housing cover are guided specifically to the attachment elements of the filter housing retaining structure. In particular, it is possible to completely avoid tilting, and so the user can connect the filter housing cover to the filter housing retaining structure by hand. 
         [0019]    The at least two filter housing cover guide members preferably protrude from the two opposite sides of the filter housing cover in a direction substantially perpendicular to an attaching direction of the filter housing cover attachment elements. 
         [0020]    The filter housing cover guide members can thus be reliably positioned in the guide elements and guided to the filter housing retaining structure. A lateral tilting or canting is prevented in this way. Accordingly, the attachment elements of the filter housing cover which are formed on the filter housing cover can be displaced precisely to the attachment elements of the filter housing retaining structure, and a reliable connection can be thereby established. 
         [0021]    It is further preferred that at least one latching member be arranged on the filter housing retaining structure and/or on the filter housing cover and/or on the filter housing to latch the filter housing cover in a connected position, in which the attachment elements of the filter housing cover are fully connected to the attachment elements of the filter housing retaining structure. 
         [0022]    The latching member offers the advantage that the user notices increased resistance shortly before the connected position, which indicates to the user that the filter housing cover has almost reached the connected position. As a result of deliberately overcoming the increased resistance, the corresponding element interlocks with the latching member, and the filter housing cover is thus retained in the connected position. The unintentional removal of the filter housing cover can thereby be prevented, and so the connection between the attachment elements of the filter housing cover and the attachment elements of the filter housing retaining structure can be reliably maintained. 
         [0023]    The latching member also preferably has a resilient latching clamp, and preferably a pin engages in said clamp when in the connected position and protrudes from the filter housing cover perpendicular to the connecting direction. 
         [0024]    Alternatively or additionally, the latching member has a snap fastener. 
         [0025]    Preferably, the attaching direction substantially corresponds to the connecting direction. 
         [0026]    As soon as the filter housing cover is engaged with the guide members, the attachment elements of the filter housing cover, which are oriented in an attaching direction, are oriented in the connecting direction. If the filter housing cover moves in the connecting direction toward the attachment elements of the filter housing retaining structure, which are preferably likewise oriented in the attaching direction, the attachment elements of the filter housing cover can be connected to the attachment elements of the filter housing retaining structure in a straight line, and so a reliable connection can be established. Any tilting to establish a connection is avoided. 
         [0027]    Further preferred is that the guide members have guide rails, which lie opposite each other and are configured linearly to correspond to the connecting direction. 
         [0028]    Alternatively or additionally, the latching member can have filter housing cover latching lugs and guide member latch recesses, wherein each of the guide members has at least one guide element latch recess, and a filter housing cover latching lug that is arranged on the filter housing cover can be latched into each recess in a connected position, in which the attachment elements of the filter housing cover are fully connected to the attachment elements of the filter housing retaining structure. 
         [0029]    Preferably, the filter housing cover guide members are mounted resiliently and/or comprise actuation surfaces extending in an attaching direction of the filter housing cover attachment elements and protruding from the filter housing cover in a direction opposite the filter housing cover attachment elements. 
         [0030]    This makes it possible for the engagement between the filter housing retaining structure and the filter housing cover to be released by pressing the actuation surfaces together. In addition, the engagement can be reinforced when the user pushes the actuation surfaces apart in the connected position in order to ensure that the filter housing cover latching lugs are reliably interlocked with the guide member latch recesses. 
         [0031]    It is further preferred that the actuation surfaces be configured such that they widen or taper in the attaching direction and/or connecting direction. 
         [0032]    Because the actuation surfaces have a widening or tapering shape, the user can grip the actuation surfaces securely. The tapering shape of the actuation surfaces in particular can further ensure that people with smaller hands are also able to operate the actuation surfaces by hand. 
         [0033]    Moreover, it is preferred that the filter housing cover latching lugs project from the filter housing guide members in a direction perpendicular to the attaching direction. 
         [0034]    Among other things, this permits the latching lugs of the filter housing cover to be clearly visible externally once the filter housing cover latching lugs have entered into the latch recesses of the guide member. The guide member latch recess are preferably configured as through-holes in the guide members for this purpose. 
         [0035]    Preferably, at least one pressure transducer is disposed on a rear end of the filter housing cover which is designed to be pushed by the user in order to connect the filter housing cover with the filter housing retaining structure. 
         [0036]    The rear end of the filter housing cover is understood in this instance to be the end that is opposite the end on which the filter housing cover attachment elements are arranged. When a user pressed on the pressure transducer, especially at the end of the connection process, the user can more easily apply the necessary force to completely connect the attachment elements of the filter housing cover to the attachment elements of the filter housing retaining structure. 
         [0037]    According to a further aspect of the present application, the problem of interest is solved by a cleaning system, which has a connecting structure corresponding to one of the aforementioned embodiments of the aforementioned aspect as well as a filter housing retaining structure, to which the filter housing cover can be connected. 
         [0038]    The filter housing retaining structure preferably has filter housing retaining structure attachment elements, which are oriented in the connecting direction and with which the filter housing cover attachment elements of the filter housing cover can be connected. 
         [0039]    Also preferably, the filter housing retaining structure attachment elements or the filter housing cover attachment elements each have at least one latching hook that, in the connected position, latches into a depression in the corresponding attachment element, with which it can be connected. 
         [0040]    Furthermore, it is preferred that the filter housing cover be connected to the filter housing cover and that the resilient latching clamp be designed to accommodate the filter housing when in the connected state. 
         [0041]    Preferably, the guide members are connected by a retaining plate arranged on a housing of the filter housing retaining structure, 
         [0042]    wherein each of the filter housing retaining structure attachment elements is inserted into a recess in the retaining plate and protrudes through it so as to be connectable with the filter housing cover attachment elements. 
         [0043]    Preferably, the filter housing retaining structure attachment element is mounted in the recess such that displacement in the connecting direction V is blocked. 
         [0044]    According to a further aspect of the present application, the problem of interest is solved by a filter housing cover for a filter housing, which can be connected to a filter housing retaining structure that is designed to supply a fluid that is to be cleaned and to discharge the purified fluid, 
         [0000]    wherein the filter housing cover is designed to be connected to the filter housing,
 
wherein the filter housing cover has at least two filter housing cover attachment elements, which can be connected to corresponding filter housing retaining structure attachment elements in order to establish an exchange of fluid between the filter housing retaining structure and the filter housing; and
 
         [0045]    wherein the filter housing cover has at least two filter housing cover guide members, which are provided on opposite sides of the filter housing cover and are designed to engage in guide members that can be attached to the filter housing retaining structure during the process of connecting the attachment elements of the filter housing cover with the attachment elements of the filter housing retaining structure in order to support and guide the filter housing cover during the connection process and to mount it such that it can be displaced in a linear connecting direction. 
         [0046]    According to a further aspect of the present application, the problem of interest is solved by a method for connecting a filter housing cover to a filter housing retaining structure, wherein the method comprises:
       providing a cleaning system corresponding to one of the embodiments of the aforementioned further aspect of the present application;   inserting the filter housing cover guide members into the guide members such that the filter housing cover guide members are supported in the guide members;   displacing the filter housing cover linearly in the connecting direction until the attachment elements of the filter housing cover are connected to the attachment elements of the filter housing retaining structure.       
 
         [0050]    The method preferably further includes the step of latching the filter housing cover or the filter housing to the filter housing retaining structure by means of at least one latching member. 
         [0051]    These and other objectives, features and advantages of the present invention will become more apparent upon reading the following detailed description of preferred embodiments and the accompanying drawings. It is clear that, although embodiments are described separately, individual features thereof may be combined into additional embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0052]      FIG. 1  shows a guide frame by means of which a filter housing can be connected to a filter housing retaining structure. 
           [0053]      FIG. 2  shows a cross-sectional view of a connector plug and a connector socket. 
           [0054]      FIG. 3  shows a latching clamp as means for latching a filter housing in a connected position. 
           [0055]      FIG. 4  shows latching hooks as means for latching a filter housing in the connected position. 
           [0056]      FIG. 5  shows a snap fastener as means for latching a filter housing in the connected position. 
           [0057]      FIG. 6 a   )-c) show a filter housing cover with filter housing cover latching lugs which, in the connected state, engage in guide member latching recesses in the guide members, and widening actuation surfaces. 
           [0058]      FIG. 7 a   )-b) show the filter housing cover according to  FIG. 6  in a connected state and in a state before the filter housing cover is inserted into the guide members. 
           [0059]      FIG. 8  shows an embodiment similar to the embodiment according to  FIGS. 6 and 7 , but with narrowing actuation surfaces. 
           [0060]      FIG. 9  shows a filter housing according to the embodiment in  FIG. 8  before the filter housing cover is inserted into the guide members. 
           [0061]      FIG. 10  shows a perspective view of a preferred filter housing cover and a preferred guide frame. 
           [0062]      FIG. 11  shows a sectional view through the guide frame and the filter housing cover according to  FIG. 10 , which are sectioned along the connecting direction V. 
           [0063]      FIG. 12  shows a perspective view of the guide frame and the filter housing cover according to  FIGS. 10 and 11  from the rear side. 
       
    
    
     DETAILED DESCRIPTION 
       [0064]      FIG. 1  shows a filter housing  1  having a tubular base body  3 . A base body interior of the base body  3  is configured to receive a filter medium or multiple different filter media (not shown), such as activated carbon and/or resin, to clean a fluid, e.g. water. For this purpose, the filter media can be loaded directly into the base body interior or introduced into the base body by means of filter cartridges containing the filter medium. 
         [0065]    To close the base body interior inwardly, the filter housing  1  further includes a filter housing base  11  on or near a first free end  9  and a filter housing cover  15  on or near a second free end  13 . The filter housing base  11  and/or the filter housing cover  15 , together with the base body  3 , can be formed from one piece or can be non-detachably interconnected from multiple parts. However, in order to allow the filter cartridge or filter medium to be changed, it is preferred that the filter housing base  11  and/or the filter housing cover  15  be configured separately from the base body  3  and thus detachably connected to each other. For example, the filter housing base  11  and the filter housing cover  15  can be screwed on to the base body  3  or interlocked with it. 
         [0066]    The filter housing cover  15  has at least two connector plugs  17  as preferred attachment elements for the filter housing cover, each of which can be connected to a corresponding connector socket (not shown in  FIG. 1 ) as the preferred attachment elements of a filter housing retaining structure  300  in order to establish a fluid connection between the filter housing retaining structure  300  and the filter housing  1 . In other words, a fluid to be cleaned can be conducted from the filter housing retaining structure  300  to the filter medium in the filter housing  1 , preferably by means of a pump (not shown), via a connection between the connector plugs  17  and the connector sockets. Moreover, the purified fluid (e.g. pure water or ultrapure water) can be returned to the filter housing retaining structure  300  in a collection tank for the purified fluid. For instance, a fluid connection between a first connector plug  17  and a first connector socket is used to conduct a fluid that is to be cleaned to the filter medium in the filter housing  1 , while a fluid connection between a second connector plug  17  and a second connector socket is used to return the purified fluid back to collection tanks provided for this purpose. 
         [0067]    Although the present application describes the provision of connector plugs  17  only in reference to the filter housing cover  15 , the filter housing base  11  can also have connector plugs. In particular, the filter housing cover  15  and the filter housing base  11  can be configured identically. 
         [0068]    Furthermore, although  FIG. 1  shows a filter housing cover  15  with connector plugs  17 , connector sockets can alternatively be configured on the filter housing cover  15 , while the connector plugs  17  are arranged on the filter housing retaining structure  300 . 
         [0069]    Additionally, the connector plugs  17  are oriented parallel to each other and on the same side of the filter housing cover  15 . As is shown in  FIG. 1 , the connector plugs  17  project from the filter housing cover  15 . The connector plugs  17  can be configured integrally with the filter housing cover  15  or can be at least partly formed as separate components. In the latter case, the connector plugs  17  can be connected to the filter housing cover  15  preferably by means of a latched, screwed or adhered connection. 
         [0070]      FIG. 2  shows a cross-sectional view of a connector plug  17  and a connector socket  19 . 
         [0071]    The orientation of the connector plug  17  and the connector socket  19  is designated attaching direction A. In order for the connector plug  17  to be connected to the connector socket  19 , the attaching direction A of the connector plug  17  and of the connector socket  19  must be identical. In particular, the attaching direction A corresponds to the rotary axis of the connector plug  17  and connector socket  19 . 
         [0072]    In order to be able to establish a fluid-tight connection between the connector plug  17  and the connector socket  19 , the connector plug  17  has on an outer side  21  at least one circumferential notch  23 , into (each of) which a sealing element  25  is inserted. When the connector plug  17  is in a connection state with the connector socket  19 , the sealing element  25  comes into contact with an inner side  27  of the connector plug  19 , and so a fluid-tight connection is established between the attachment elements. 
         [0073]    Alternatively, at least one notch can be formed in the inner lateral surface of the connector socket  19  in which the sealing element  25  is arranged. 
         [0074]    The sealing element  25  can be a circular sealing ring, a quad ring, a C ring, an  0  ring, a D ring or an L ring, or it can be sprayed on in a two-component plastic system. Preferably, the sealing element  25  is provided with a coating, such as Teflon, and/or a lubricant, which permits improved latching of the filter housing  1  with the filter housing retaining structure  300 . A Teflon-coated quad ring is considered especially preferable. 
         [0075]    In order to connect the filter housing  1  containing the filter medium to the filter housing retaining structure  300  and to retain and support it there, the filter housing retaining structure  300  has guide members. These guide members can preferably be configured in a guide frame  100  that is arranged on the filter housing retaining structure  300 , as shown in  FIG. 1 . In particular, the guide members are designed to support the filter housing  1  during the connection process and to guide it to a connected position, in which the filter housing  1  is connected to the filter housing retaining structure  300 . 
         [0076]    The guide members and/or the guide frame  100  can be configured with a housing  302  of the filter housing retaining structure  300  as a structural unit or can be attached to the filter housing retaining structure  300 . In the latter case, the guide members or guide frame  100  can preferably be connected to the filter housing retaining structure  300  with an adhesive bond or screwed to it. 
         [0077]      FIG. 1  shows a separately configured guide frame  100 , which is arranged on the filter housing retaining structure  300 . 
         [0078]    The guide frame  100  has at least two guide frame sides  102 , which are oriented substantially parallel to each other and project from the filter housing retaining structure  300 . Preferably, the guide frame sides  102  project from a vertical lateral surface of the housing  302  of the filter housing retaining structure  300  at a preferably right angle to the corresponding vertical lateral surface, which corresponds to a connecting direction V. 
         [0079]    The distance between the at least two guide frame sides  102  is configured such that the filter housing  1  can be arranged at least partly between the guide frame sides  102 . 
         [0080]    The at least two guide frame sides  102  can be connected directly to the filter housing retaining structure  300 . Alternatively, the at least two guide frame sides  102  can be connected by means of a guide frame retaining plate  104 . Said guide frame retaining plate  104  preferably connects the first free ends  106  of each of the two guide frame sides  102 . The first free end  106  is here considered to be the end of the guide frame sides  102  adjacent to the filter housing retaining structure  300 . 
         [0081]    The guide frame retaining plate  104  connects the guide frame sides  102  while at the same time preferably serving to attach the guide frame  100  to the filter housing retaining structure  300 . 
         [0082]    At least one attachment element recess  108  is formed in the guide frame retaining plate  104 , through which the connector sockets (not shown in  FIG. 1 ) protrude at least in part. If the guide frame retaining plate  104  has more than one attachment element recess  108 , then a connector socket  19  preferably projects through each one. 
         [0083]    A guide member is formed on or in each lateral surface  110  of the guide frame sides  102 , which face each other. As is shown in  FIG. 1 , these guide members are preferably formed as guide rails  112 . The guide rails  112  preferably extend over the entire length of the guide frame sides  102  from a second free end  114  to the corresponding first free end  106 . The second free end  114  of a guide frame side  102  is arranged opposite the first free end  106 . 
         [0084]    The guide rail  112  is open at the second free end  114  so that a filter housing cover guide member  29  on the filter housing cover  15 , which will be described hereafter, can be inserted into the guide rail  112  via the open end. 
         [0085]    The end of the guide rail  112  at the first free end  106  of the guide frame side  102  is closed by a lateral surface of the filter housing retaining structure  300  or, as is shown in  FIG. 1 , by the guide frame retaining plate  104 . 
         [0086]    The guide rails  112  are substantially linear so as to permit a linear displacement of the filter housing cover  15  and thus of the filter housing  1 . 
         [0087]    In particular, the guide rails  112  are configured parallel to each other so that the filter housing cover  15  can be displaced into the guide rails  112  in a consistent straight line. Any tilting is thereby avoided. 
         [0088]    Nevertheless, it is possible that the guide rails  112  are widened on or adjacent to the first free end  106  of the guide frame side  102 . 
         [0089]    The orientation of the guide rails  112  corresponds to the connecting direction V in which the filter housing cover  15  can be displaced toward the filter housing retaining structure  300 . 
         [0090]    It should be noted here that any descriptions of the guide members or the guide rails  12  without the guide frame  100  are also valid. The configuration of the guide members and the guide rails  12  in a guide frame  100  is understood to be only a preferred embodiment. 
         [0091]    One filter housing cover guide member  29  is provided on each of substantially opposing sides of the filter housing cover  15 , and said members preferably project from the filter housing cover  15 . The shape of the filter housing cover guide member  29  is designed such that it can engage with a guide rail  112  and can be displaceably supported within it. Preferably, the filter housing cover guide members  29  project from the filter housing cover  15  in a direction perpendicular to the attaching direction A. The filter housing cover guide members  29  can thus be configured as a structural unit with the filter housing cover  15  or can be reversibly connected to it. 
         [0092]    In other words, the guide frame  100  and guide rails  112  are configured such that it is possible to arrange a filter housing cover  15  at least partly between two guide frame sides  102  or guide rails  112 , wherein each of the filter housing cover guide members  29  on opposing sides engages in a corresponding guide rail  112 . The filter housing cover guide members  29  can be inserted into the guide rails  112  via the second free end  114  of the guide frame sides  102  and can be displaced in a linear direction within the guide rail  112  to the connected position. Accordingly, the filter housing cover  15  is supported on two sides during the connection process, and so the tilting or canting of the filter housing cover  15  can be avoided. Since the guide rails  112  have a linear shape, the filter housing cover  15  can be displaced to the connected position in a simple linear shape. Furthermore, the weight of the filter housing  1  can be borne by the guide rails  112 . 
         [0093]    Preferably, the attaching direction A of the connector plugs  17  corresponds to the connecting direction V as soon as the filter housing cover guide members  29  engage with the guide rails  112 , and so the connector plugs  17  can be guided in a substantially linear direction of movement toward the connector sockets  19 . 
         [0094]    In order to hold the filter housing cover  15  and filter housing  1  in the connected position and to prevent an unintentional separation, the filter housing cover  15  can have a pin  31  that latches with a latching member in the connected position. As is shown in  FIG. 1 , the pin  31  preferably projects from the filter housing cover  15  perpendicularly to the attaching direction A and/or the connecting direction V. 
         [0095]    The latching member can be arranged on the filter housing retaining structure  300  and/or the guide frame  100 . 
         [0096]    As is shown in  FIG. 3 , the latching member can be configured as a resilient latching clamp  116 . Said latching clamp  116  is open to one side in the connecting direction V and/or in the attaching direction A so that the pin  31  can be received by the latching clamp  116  (see latching clamp at the top of  FIG. 3 ) in the connected position. Alternatively, the latching clamp  116  (see the latching clamp lower in  FIG. 3 ) can be configured in such a way that it can receive the base body  3  of the filter housing  1  in the connected position. 
         [0097]    If the filter housing cover guide members  29  in the guide rails  112  are displaced toward the filter housing retaining structure  300  in the connecting direction V, the pin  31  and/or the base body  3  enter into the corresponding latching clamp  116  at the end of the connection process. For this to occur, the user must exert force sufficient to bend the latching clamp open resiliently so that the pin  31  or the base body  3  can be pushed into the latching clamp  116 . Once the pin  31  or base body  3  is arranged in the latching clamp  116 , the latching clamp  116  preferably moves back to its starting position, and so the pin  31  or base body  3  is retained in the latching clamp  116 . An unintended separation of the filter housing  1  from the filter housing retaining structure  300  can thereby be prevented. Moreover, the user feels the resistance of the latching clamp  116  during the connection process and thus reliably determines when the connected position has been reached, namely as soon as the resistance has been overcome. In other words, an inertial connection is established. 
         [0098]    The latching clamps  116  described above can be used as alternatives or in combination 
         [0099]    Alternatively or additionally, the latching member can be configured as at least one latching hook  118 , as is shown in  FIG. 4 . The at least one latching hook  118  projects from a free end of the connector socket  19  in the connecting direction V and/or the attaching direction A in order to engage in a depression  33  in the connector plug  17  and interlock with it in the connected state. 
         [0100]    One, two, three, four, five, six or more latching hooks  118  can be provided on a connector socket  19 . The depression  33  in the connector plug  17 , into which the latching hooks  118  of a connector socket  19  latch, can be configured as a circumferential depression  33  or can consist of multiple individual depressions  33  into each of which at least one latching hook  118  can latch. 
         [0101]    Although the latching hooks  118  according to  FIG. 4  are arranged on the connector sockets  19 , the latching hooks can alternatively be provided on the connector plugs  17 . In this case, the connector sockets  19  have the depression  33  required for engagement. 
         [0102]    Alternatively or additionally, a snap fastener  200  can aid in latching the filter housing cover  15  in the connected position. 
         [0103]      FIG. 5  shows a preferred embodiment of a snap fastener  200 . 
         [0104]    The snap fastener  200  shown in  FIG. 5  has a clasp  202  and a preferably spring-loaded catch  204 , which are interlocked in the connected state. 
         [0105]    As is shown in  FIG. 5 , the clasp  202  can be arranged on the filter housing cover  15  and can protrude from the filter housing cover  15  in the attaching direction A and/or the connecting direction V. 
         [0106]    On the other hand, the catch  204  cab be arranged on the filter housing retaining structure  300  or the guide frame  100 , preferably on the guide frame retaining plate  104 , by means of a catch retaining plate  206 . The catch  204  is rotatably mounted around a catch rotary axis SR so that it can be rotated between an open and a closed position. 
         [0107]    In the open position of the catch  204 , the filter housing cover  15  can be displaced to the connected position and the filter housing cover  15  can be removed from the connected position. Once the filter housing cover  15  has reached the connected position, the catch  204  rotates about the catch rotary axis SR so as to engage with the clasp  202  and latch with it. 
         [0108]    The connection can be released only when the user actively unlatches the snap fastener  200 , and so a reliable connection between the attachment elements is ensured. 
         [0109]    Although  FIG. 5  shows that the clasp  202  is arranged on the filter housing cover  15  and the catch  204  is attached to the guide frame  100 , it is likewise possible that the clasp is arranged on the guide frame  100  and the catch  204  is on the filter housing cover  15 . 
         [0110]    Furthermore, the corresponding catch component can also be arranged on the filter housing retaining structure  300  itself rather than on the guide frame  100 . 
         [0111]    A magnetic closure and a quick connector are other alternatives of an engagement which are not shown. 
         [0112]      FIG. 6  shows a further alternative of a latching member that can be used to retain the filter housing  1  and the filter housing cover  15  in the connected position, in which the attachment elements are fully connected to each other by means of a latching connection. 
         [0113]    In the present case, the latching member has filter housing cover latching lugs  35  on the filter housing cover  15  and has guide member latching recesses  120  in the guide members. 
         [0114]    As is shown in  FIG. 6 b   ), which corresponds to a sectional view along section line A-A in  FIG. 6 a   ), the filter housing cover  15  has filter housing cover guide members  29 , which are arranged on opposite sides of the filter housing cover  15  in a direction preferably perpendicular to the attaching direction A and/or connecting direction V. It is further preferred that the filter housing cover guide members  29  be located substantially on one plane. 
         [0115]    The filter housing cover guide members  29  have elongate filter housing cover guide elements  37 , which preferably extend in connecting direction V and/or attaching direction A. In particular, the filter housing cover guide elements  37  are congruent in shape with the guide members, at least in some areas, so that they can at least partly enter into and be guided within the guide members during the process of connecting the filter housing  1  to the filter housing retaining structure  300 . 
         [0116]    The filter housing cover guide elements  37  are each spaced from the filter housing cover  15  by at least one spacer member. The spacer member is configured to attach the filter housing cover guide elements  37  to the filter housing cover  15  and to mount the filter housing cover guide elements  37  resiliently. The spacer member can be configured as a spacing bracket  39 . As is shown in  FIG. 6 b   ), two spacing brackets  39  can preferably be placed such that they arrange a filter housing cover guide element  37  on the filter housing cover  15 . To permit a resilient movement of the filter housing cover guide element  37 , the spacing brackets  39  are distanced from one another in attaching direction A and/or connecting direction V. Moreover, the length and thickness of the spacing brackets  39  are designed according to how far the filter housing cover guide elements  37  can be deflected and how smoothly this movement can be executed. 
         [0117]    The spacing brackets  39  preferably project from the filter housing cover  15  in a direction perpendicular to the attaching direction A and/or the connecting direction V. The length of the spacing brackets  39  defines the distance between the filter housing cover guide elements  37  and the filter housing cover  15 . 
         [0118]    The spacing brackets  39  are connected to the filter housing cover guide elements  37  at or near the first end  41  of the filter housing cover guide elements  37 . The first end  41  of the filter housing cover guide elements  39  is considered in this instance to be the end that is closer to the connector plugs  17  of the filter housing  1 . “Close” to the first end  41  is considered to be a distance of approximately 5 mm to 30 mm, preferably approximately 10 mm to 25 mm, and preferably approximately 15 mm to 20 mm. 
         [0119]    Preferably, a filter housing cover latching lug  35  is arranged on a side of the filter housing cover guide elements  37  that faces away from the filter housing cover  15 . The filter housing cover latching lug  35  preferably has an inclined surface  43  that rises, preferably continuously, from a side closer to the connector plugs  17  in the attaching direction A. Alternatively, the inclined surface  43  can rise discontinuously or step-wise or trapezoidally. A second surface of the filter housing cover latching lug  35  extends perpendicularly to the filter housing cover guide element  37  and serves as a latching surface  45  for the latching lug. 
         [0120]    The guide members or, as is shown in  FIG. 6 , the guide rails  112  each have at least one guide member latching recess  120 . This recess can be configured as an opening that is penetrated by the guide rail  112  or as a depression, wherein the depression must be formed in a lateral surface of the guide rail  112  that faces the filter housing cover  15  when the filter housing cover  15  is deployed. 
         [0121]    In the connected state when the attachment elements are fully connected, the filter housing cover latching lugs  35  can each be latched into the latch recesses  120  of the guide members. 
         [0122]    The width of the filter housing cover  15 , including the spacing brackets  39  and the filter housing cover guide elements  37 , is preferably such that the filter housing cover guide elements  37  can be inserted into the guide rails  112  and displaced within them. However, the width of the filter housing cover  15 , including the spacing brackets  39  and the filter housing cover guide elements  37  plus the filter housing cover latching lugs  35 , is greater than the width between the outer surfaces  122  of the guide rails  112 . The outer surface  122  is considered in this instance to be the surface of the guide rails  112  that faces the filter housing cover  15  when the inserted state. 
         [0123]    The filter housing cover latching lugs  35  are preferably arranged in a position that is further away from the connector plugs  17  than the spacing brackets  39 . 
         [0124]    If the filter housing cover  15  and the filter housing cover guide elements  37  are inserted into the guide rails  112 , then the filter housing cover  15  can be displaced in connecting direction V until the guide rail  112  comes into contact with the filter housing cover latching lugs  35 . The filter housing cover guide element  37  is resiliently deflected as a result of this contact, and so the filter housing cover guide elements  37  are deflected toward the filter housing cover  15 , at least in the region behind the spacing brackets  39 . “Behind” the spacing brackets  39  is considered to be the area of the filter housing cover guide elements  37  that lies opposite the side of the connector plug  17  in the attaching direction A. 
         [0125]    If the filter housing cover  15  is pushed further in the connecting direction V, the outer surface  122  of the guide rail  112  slides along the inclined surface  43  of the filter housing cover latching lug  35 . Once the filter housing cover latching lug  35  reaches the guide member latch recess  120 , the filter housing cover guide elements  37  move back to their original position, and so each of the filter housing cover latching lugs  35  latches with a corresponding guide member latch recess  120 . In particular, the latch surface  45  of the latching lug, which is in contact with the guide rail  112 , prevents the filter housing cover  15  from being pulled out inadvertently. 
         [0126]    To release the engagement or to support the engagement process, the filter housing cover guide elements  37  can each have an actuation surface  47 . The filter housing cover guide elements  37  can be elongated in the attaching direction A in a direction counter to the direction in which the connector plug  17  projects. This elongated section can act as an actuation surface  47  for the user. Preferably, the actuation surface  47  projects beyond the guide rails  112  in the connected state. 
         [0127]    As is shown in  FIGS. 6 b   ) and  6   c ), the actuation surface  47  is curved upward, and so the distance between the filter housing cover guide elements  37  tapers toward the connector plugs  17  in attaching direction A. 
         [0128]    By pressing the filter housing cover guide elements  37  together, the user can resiliently deflect the filter housing cover guide elements  37 . The engagement can be released in this way. The engagement can be reinforced when the filter housing cover guide elements  37  are pushed apart by the actuation surfaces  47 . 
         [0129]    The actuation surfaces  47  preferably taper in a curved shape. In so doing, the curved shape can be adapted to the natural shape of a human finger. Additionally, an actuation surface bulge  49  can be formed on the free end of the actuation surfaces  47 . This can ensure that the user&#39;s fingers can rest securely on the actuation surfaces  47  and slipping can be prevented. 
         [0130]    In a preferred embodiment, the guide rails  112  are formed with a filter housing cover enclosure  400 . 
         [0131]    The filter housing cover enclosure  400  connects to one of the two guide rails  112  and can additionally be used to attach the guide rails  112  to the filter housing cover retaining structure  300 . 
         [0132]    The filter housing cover enclosure  400  has an enclosure connecting element  402  for this purpose. Enclosure hoods  404  corresponding to the number of attachment elements are formed on the upper side of the enclosure connecting element  402  The enclosure hoods  404  are open toward the filter housing cover  15  in the attaching direction A and/or in the connecting direction V so that the connector plugs  17  can enter into said enclosure hoods  404 . The connector sockets  19  of the filter housing retaining structure  300  are covered by the enclosure hoods  404 . When the attachment elements are in the connected state, the enclosure hoods  404  cover the attachment elements. 
         [0133]    Though represented as separate elements, the guide frame  100  and/or the filter housing cover enclosure  400  can be configured integrally with the filter housing retaining structure  300 . 
         [0134]      FIG. 7 a   ) shows the filter housing cover  15  from  FIG. 6  in the connected state of the attachment elements, which are covered by the filter housing cover enclosure  400 . 
         [0135]      FIG. 7 b   ) shows the filter housing cover enclosure  400  and the filter housing cover  15  according to  FIG. 6  in the unconnected state. 
         [0136]    The enclosure connecting element  402  can preferably be congruent in shape with the filter housing cover  15  so that, in the connected state, the surface of the filter housing cover  15  match the enclosure connecting element  402  with which it comes into contact. 
         [0137]      FIG. 8  shows an embodiment that is similar to the embodiment in  FIGS. 6 and 7  and that differs substantially in that the filter housing cover guide elements  37  taper away from the connector plugs  17  in the attaching direction A. In this way, it can be ensured that it is possible to actuate the actuation surfaces  47  with any hand size. 
         [0138]    The filter housing cover guide elements  37  can be mounted resiliently on the filter housing cover  15  for this reason, as in the embodiment according to  FIGS. 6 and 7 . Alternatively, the filter housing cover guide elements  37  can be rigidly connected to the filter housing cover  15 , as is shown in  FIG. 9 . Only the region of the filter housing cover guide elements  37 , which tapers, is configured to be resilient. The filter housing cover latching lugs  35  and the actuation surfaces  47  are arranged in the tapering region. The rigid region of the filter housing cover guide elements  37  is the region that can be guided within a guide member or a guide rail  112 . This region is preferably congruent in shape with the guide members and guide rails  112 . 
         [0139]    Although it is described in  FIGS. 6 through 9  that the actuation surfaces  47  are all configured identically, the shapes of the actuation surfaces  47  can deviate from each other in their individual forms. 
         [0140]    It should be noted that combinations of the latching members illustrated above are likewise possible. 
         [0141]      FIG. 10  shows a perspective view of a preferred guide frame  100  and a preferred filter housing cover  15 . However, as is shown in  FIG. 10  and similar to the filter housing cover  15  in  FIGS. 8 and 9 , the filter housing cover  15  differs in that at least one pressure transducer  51  is provided on a rear end of the filter housing cover  15 , which is oriented opposite the end on which the connector plugs  17  are arranged. The pressure transducer  51  is designed as an actuation surface for at least one of the user&#39;s fingers, which can be placed on the pressure transducer  51  in order to displace the filter housing cover  15  within the guide frame  100  and to apply the pressure necessary to fully engage the connector plug  17  with the connector socket  19 . Preferably, the pressure transducer  51  is curved to prevent the finger from shifting or sliding off. Moreover, the pressure transducer  51  can be provided with a grooved or roughened surface. This can likewise prevent the finger from sliding off. 
         [0142]    Although the pressure transducer  51  in  FIG. 10  is arranged on a filter housing cover  15  according to  FIGS. 8 and 9 , the pressure transducer  51  also be arranged on any other filter housing cover  15  of the other embodiments described. 
         [0143]    The preferred embodiment of the guide frame  100  in  FIG. 10  is described in greater detail with reference to  FIG. 11 . 
         [0144]      FIG. 11  shows a sectional view through the filter housing cover  15  and the preferred guide frame  100  according to  FIG. 10 , which are sectioned along the connecting direction V. 
         [0145]    One connector socket  19  can be formed in each of the attachment element recesses  108  that are formed in the retaining plate  104  of the guide frame  100 . A front end  53  of the connector socket  19  projects into an interior space  124  of the guide frame  100 , which is formed between the opposing sides  102  of the guide frame. The connector plugs  17  can protrude to different depths in the interior space  124  depending upon the arrangement of the connector plugs  17  on the filter housing cover  15 . 
         [0146]    A connector socket receiving space  57  is formed at the front end  53  of the connector socket  19 , in which the connector plugs  17  can each be at least partly accommodated. The size and/or shape of the connector socket receiving space  57  is/are adapted to the shape and/or size of the connector plug  17  in such a way that a fluid-tight connection can be established between the connector plug  17  and the connector socket  19 . This can be ensured by the abovementioned sealing rings  25 , which are provided on the connector plugs  17 , for example. Alternatively, at least one sealing ring  25  can be provided in the connector socket receiving space  57 . 
         [0147]    Furthermore, a rear end  59  of the connector socket  19 , which is opposite the front end  53  of the connector socket  19 , can protrude out of the guide frame  100 . When the guide frame  100  is connected to a filter housing retaining structure  300  (not shown here), the rear end  53  of the connector socket  19  preferably projects into an interior space of the housing of the filter housing retaining structure (not shown here) in order to be connected there to the collection tank for the fluid, e.g. by means of hoses. To permit a transfer of fluid through the connector socket  19  for this purpose, at least one fluid duct  61  extends from the connector socket receiving space  57  to the rear end  59  of the connector socket  19 . 
         [0148]    At least one circumferential step  65  and/or notch is formed in a lateral surface  63  of the connector socket  19 , which extends around the connecting direction V or the attaching direction A. A circumferential step  65  is preferably configured such that the connector socket  19  tapers at this point from the front end  53  to the rear end  59 . The tapering section of the connector socket  19  can then protrude through the attachment element recess  108  of the guide frame  100 , while the wider section of the connector socket  19  is wider or larger than the connector socket recess  108 , so that the connector socket  19  rests upon the guide frame retaining plate  104  in a preferably form-fitting way with the aid of the step  65 . If it is a notch, the circumferential edge of the attachment element recess  108  projects into the notch. In this way, a fixed arrangement of the connector socket  108  on the guide frame  100  is likewise achieved. 
         [0149]    If the connector socket  19  has a step  65 , then the connector socket  19  can be secured against slipping in the connecting direction V or attaching direction A (X direction) with the aid of at least one securing ring  67 , as is shown in  FIG. 12 . 
         [0150]    Preferably, the size of each connector socket  19  and attachment element recess  108  is dimensioned such that the connector socket  19  has 0.5 mm to 1 mm of play in the Y-Z plane within the attachment element recesses  19 , i.e. they are moveably mounted in accordance with the play in the Y axis and/or Z axis (the X axis corresponds to connecting direction V). The outer connector sockets  19  preferably have less play than the middle connector socket(s)  19 . For example, the outer connector sockets  19  have 0.5 mm of play, whereas the middle connector socket(s) have 1 mm of play. Connecting the connector sockets  19  to the connector plugs  17  can be facilitated by the additional play, and so connecting the filter housing retaining structure  1  to the filter housing retaining structure  300  is improved for the user. 
         [0151]    Although connector sockets  19  of the type in  FIGS. 10 through 12  are connected to the guide frame  100 , the connector sockets  19  can also be inserted into corresponding recesses in the housing  302  of the filter housing retaining structure  300  if, for instance, the guide frame  100  does not have a guide frame retaining plate  104 . Moreover, connector sockets  19  such as these can be employed in any of the previously described embodiments. 
         [0152]    In addition, each of the engagements illustrated above can contain an electric/electronic intelligence that detects the connection with the cartridge cover  15 . In this case, electric closers/openers, relays or electronic sensors such as NFC (“near field communication”) or RFID (“radio-frequency identification”) are possible. It is also conceivable that the position and type of the cleaning cartridge inserted can be recognized by means of a barcode. 
       LIST OF REFERENCE SIGNS 
       [0000]    
       
           1  Filter housing 
           3  Base body 
           9  First free end of the base body 
           11  Filter housing base 
           13  Second free end of the base body 
           15  Filter housing cover 
           17  Connector plug 
           19  Connector socket 
           21  Outer side of the connector plug 
           23  Notch 
           25  Sealing element 
           27  Inner side of the connector socket 
           29  Filter housing cover guide member 
           31  Pin 
           33  Depression 
           35  Filter housing cover latching lug 
           37  Filter housing cover guide element 
           39  Spacing bracket 
           41  First end of the filter housing cover guide element 
           43  Inclined surface of the filter housing cover latching lug 
           45  Latching lug latch surface 
           47  Actuation surface 
           49  Actuation surface bulge 
           51  Pressure transducer 
           53  Front end of the connector socket 
           57  Connector socket receiving space 
           59  Rear end of the connector socket 
           61  Fluid duct 
           63  Lateral surface of the connector socket 
           65  Step 
           67  Securing ring 
           100  Guide frame 
           102  Guide frame side 
           104  Guide frame retaining plate 
           106  First free end of the guide frame side 
           108  Attachment element recess 
           110  Opposite lateral surface of the guide frame sides 
           112  Guide rail 
           114  Second free end of the guide frame side 
           116  Latching clamp 
           118  Latching hook 
           120  Guide member latch recess 
           122  Outer surface of the guide rail 
           124  Interior space of the guide frame 
           200  Snap fastener 
           202  Clasp 
           204  Catch 
           206  Catch retaining plate 
           300  Filter housing retaining structure 
           302  Housing for the filter housing retaining structure 
           400  Filter housing cover enclosure 
           402  Enclosure connecting element 
           404  Enclosure hood 
         A Attaching direction 
         SR Rotary axis of the catch 
         V Connecting direction