Patent Abstract:
A device for extracting and fragmenting substances, especially infectious or malodorous substances, in a laboratory test vessel ( 3 ) is provided. The device includes a processing tool ( 11 ) and a stirrer element ( 33 ). An interior of the laboratory test vessel ( 3 ) is subdivided by a sieve ( 59 ) into a collection chamber and a processing chamber. The sieve ( 59 ) prevents parts of the substances having a defined rain size from reaching the collection chamber ( 73 ). A sample can be taken from the collection chamber using a pipette ( 45 ) which is passed through the stirrer element ( 33 ) and the sieve ( 59 ).

Full Description:
BACKGROUND 
       [0001]    The subject matter of the invention relates to a device for extracting, fragmenting, mixing, and homogenizing especially infectious, malodorous, chemically corrosive, or sterile substances according to the preamble of claim  1 . 
         [0002]    Devices of this type are known. From WO2004/035191 a one-way mixer and homogenizer is known, comprising a tubular laboratory test vessel, with an agitating element being supported for rotation in its lid having cutting and/or squeezing elements. At the periphery of the agitating element, connected in a torque-proof manner to the laboratory test vessel, cutting edges are formed at a retention sheath with the agitating element engaging them. Using this one-way mixer and homogenizer in particular infectious, malodorous, chemically corrosive, or sterile substances can be mixed and homogenized. 
         [0003]    The substances processed inside the homogenization and mixing chamber remain hermetically isolated from the environment in this manner and, when the desired consistency has been reached, they can be removed via the shaft of the agitating element, which is hollow, without requiring the laboratory test vessel to be opened. 
         [0004]    The disadvantage of this device is that when processing fibrous or chord-containing substances, the latter may clog the opening of the pipette for suctioning the processed sample and thus essentially hinder the removal of the test amount of the substance. 
       SUMMARY 
       [0005]    The object of the present invention is to provide a device for extracting, fragmenting, mixing, and homogenizing in particular infectious, malodorous, chemically corrosive, or sterile substances of the type mentioned at the outset, in which the substances to be processed, even when provided only in smallest amounts, are constantly guided past the processing tool during processing and processed. 
         [0006]    Another object of the present invention is to provide a device for extracting, fragmenting, mixing, and homogenizing in particularly infectious, malodorous, chemically corrosive, or sterile substances of the above-mentioned type, which allow a simple and malfunction-free removal of the substance processed in the device. 
         [0007]    This object is attained in a device having the features of claim  1 . Advantageous embodiments of the invention are described in the dependent claims. 
         [0008]    The substances unprocessed and being processed are guided past the processing tool by a helically shaped transportation means until the desired consistency is achieved. It is further achieved by a sieve, dividing the processing space in the laboratory test vessel, to separate unnecessary unmilled or to be milled components still contained in the sample to be processed from the optimally homogenized, fragmented, i.e. extracted substances. In a particularly advantageous embodiment of the invention, the removal of these separated materials can occur directly through the hollow shaft of the processing element and, if provided, through a sieve that can be penetrated, without opening the laboratory test vessel. The arrangement of the surface in the sieve that can be penetrated at a tubular or dome-shaped attachment facilitates the penetration of the desired fraction from the processing chamber into the collection chamber. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Using two illustrated exemplary embodiments the invention is explained in greater detail. Shown are: 
           [0010]      FIG. 1  an axial cross-sectional view through a device for processing substances in a laboratory test vessel, 
           [0011]      FIG. 2  a view of the device from the direction according to arrow P in  FIG. 1 , 
           [0012]      FIG. 3  a cross-sectional view through the device taken along a line III-III in  FIG. 1 , 
           [0013]      FIG. 4  an enlarged representation of the area A in  FIG. 1 , 
           [0014]      FIG. 5  a view of the lid, 
           [0015]      FIG. 6  an exploded perspective view of the elements used in the laboratory test vessel, 
           [0016]      FIG. 7  an axial cross-sectional view through the device with a partially inserted pipette, and 
           [0017]      FIG. 8  an axial cross-sectional view through another embodiment of the device without a guiding function of the laboratory test vessel. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    In  FIG. 1  the casing of a laboratory test vessel  3  is marked with the reference character  1 . The vessel is positioned upside-down, i.e. on the lid  5 , with its opening  7  pointing downwards, with the lid sealing the opening  7  of the laboratory test vessel  3 . The bottom  9  of the laboratory test vessel  3  is therefore located on the top in these figures. Processing of substances to be extracted, fragmented, mixed, or homogenized occurs in this position. In the following, the term “processing” always characterizes extracting, fragmenting, mixing, and/or homogenizing. 
         [0019]    A processing tool  11  is mounted to the lid  5  in a rotation-proof manner. The tool is arranged conically, for example with a multitude of teeth  13 . The teeth  13  can be arranged in one or more axially off-set planes in reference to each other. In the illustrated example, the three groups of teeth  13 , arranged axially behind each other and showing the form of conical wheels, are arranged on the processing tool  11 . The lowermost positioned row of teeth can have a longer distance from the second lowermost row such that at the face a coaxially arranged cutting blade  15  can be placed onto the circular step  17 . 
         [0020]    The just described part of the processing tool  11  is mounted to the collar  19  of the lid  5 , which extends into the interior of the casing  1  of the laboratory test vessel  3 . A flange  21  of the lid  5  surrounds the upper brim  23  of the laboratory test vessel  3 . Preferably the brim of the lid  5  is provided with a bead  25  pointing inwards, which extends into a recess  27  provided at the upper edge of the casing  1 . As an alternative to the just described snap-action lid  5  instead of a bead  25  and recess  27 , a thread or a bayonet fitting may be used, of course. 
         [0021]    The processing tool  11  comprises a central bore  29  serving as a gliding bearing for a guidance tube  31  of an agitating element  33 . At the end facing the lid, this bearing bore  29  is provided with a rib  35  pointing inwardly, which engages an encircling groove  37  at the guidance tube  31  for axially guiding the latter. At the upper end of the bore  29  in the processing tool  11 , encircling ribs  39  are formed, facing against the guidance tube  31 , which form a labyrinth seal (cf. also the enlarged illustration of the area A in  FIG. 4 ). On the end of the guidance tube  31  facing away from the lid  5 , a cap  41  is provided having a, for example, conically extending tip  43 . The cap  41  is formed in the area of the tip  43  (the highest area) such that it can be penetrated by the tip of a pipette  45 . The tip  43  can either be provided with a predetermined breaking point or may be made from an elastic material penetrable by the pipette tip. Of course, the area that can be penetrated may comprise the same material as the guidance tube  31  and can be produced together with it in a one-component or two-component method. The cap  43  is preferably located, as discernible from  FIG. 2 , in a plane E inclined in reference to the symmetry axis of the guidance tube  31 . The inclined plane E causes materials resting thereupon during processing to automatically glide off and be guided back to the teeth  13 . 
         [0022]    At the periphery of the agitating element  33 , a transportation means  47 , made from plastic or metal, extends with a helical form. The interior edge  51  of the transportation means  47  extends in the surface of the casing of a virtual frustum, formed by the edges of the teeth  13 . The exterior edge  49  contacts a partial area of the casing  1  of the guidance tube  31 . Thus, in the area of the processing tool  11 , the interior edge  51  is guided past the crowns of the teeth  13  in a grinding and cutting manner. Therefore, when the agitating element  33  is rotated in the processing tool  11 , the transportation means  47  passes over the space between the casing  1  of the laboratory test vessel  3  and the processing tool  11  and/or the cutting blade  15  positioned thereabove. Preferably, slots  53  are provided in the transportation means  47 , which can allow the penetration of fluids from the top downwards and together with the cutting blades  15  serve for a coarse fragmenting of the sample. 
         [0023]    The rotary drive of the guidance tube  31  and/or the agitating element  33  with the transportation means  47  occurs by an external drive motor, not shown, with its drive shaft engaging through the lid  5  into the interior of the guiding tube  31 . The formfitting entraining of the guidance tube  31  is here ensured by cuts  55  arranged at its bore or by fine teeth. 
         [0024]    A pin  57  can be placed at the end of the guidance tube  31  facing the lid for transporting the laboratory test vessel  3 , in particular after samples were taken, into the lab and/or for additional support. In the embodiment of the invention shown in  FIGS. 1-7 , a sieve  59  is inserted at the bottom end of the laboratory test vessel  3  and is held in the desired axial position by suitable means  61 . The periphery of the sieve  59  contacts the interior wall of the casing  1  in a sealing manner. The sieve  59 , as shown in  FIG. 3  in an enlarged fashion, may be a perforated plate or it may comprise one or more wire or plastic grids positioned overtop of each other. Within the surface of the sieve a tubular or dome-shaped attachment  63  is provided, which extends beyond the sieve  59  at the side of the lid. A surface  65  that can be penetrated is provided at the attachment  63  above its opening cross-section positioned at the bottom. Preferably, this area  65  is formed conically tapering in a direction towards the sieve  59  and formed such that it can easily be penetrated by the tip of a pipette  45 . For this purpose, predetermined breaking points or lines  66  shall be embodied in the area  65 , or the area  65  comprises an elastic, easily penetrated membrane. The conically tapering area  65  is positioned coaxially and at a short distance from the tip  43  at the agitating element  33 . 
         [0025]    In order to increase the effectiveness of the transportation means  47 , in the first exemplary embodiment according to  FIG. 1 , the casing  1  narrows by an angle of 120°, for example, with the upper end of the narrowed section  67  may form a chord  69  in the casing  1 . The cross-section of the casing  1  above the chord  69  therefore resembles an arc (cf.  FIG. 3 ). 
         [0026]    The base  9  of the laboratory test vessel  3  can be level or bossed or, as shown in  FIG. 1 , be provided with a sump  71 . The end at the bottom of the lab test housing  3  may also be provided with a collar  75  as a support surface. 
         [0027]    In the following the operation of the device is explained. 
         [0028]    The completely assembled laboratory test vessel  3  shown in  FIG. 1  is opened by removing the lid  5  and then the substance to be processed can be inserted into the interior from the top through the opening  7 . The resealed laboratory test vessel  3  with its content is brought to the lab. Now, the laboratory test vessel  3  is brought into the position (lid  5  at the bottom) shown in  FIG. 1 , and the drive shaft of a motorized drive (not shown) is placed into it. Depending on the rotation of the drive shaft and the processing period, the test substance contained in the laboratory test vessel  3  is now guided over the teeth  13  by the transportation means  47 . The transportation means  47  additionally causes the processed substance to be guided constantly in the axial direction within the laboratory test vessel  3  from the bottom upwards and/or from the top downwards to the teeth  13 . As soon as the desired fragmenting or homogenization is achieved the operator removes the laboratory test vessel  3  from the drive, turns it such that the lid  5  is on the top. The processed substance can now flow through the sieve  59  into a collection chamber  73 . Coarse parts are held back above the sieve  59 . 
         [0029]    Now, through the hollow guidance tube  31 , the pipette  45  can be guided through the cap  41  and from there, guided by the conical area  65 , be pierced into the attachment  63 . The tip of the pipette  45  is now located in the collection chamber  73  between the bottom of the sieve  59  and the floor  9  of the laboratory test vessel  3 . The desired end product of the processing in chamber  73  is therefore free from parts, which could clog the suction opening of the pipette  45 . After the sample is taken, a pin  57  can again be placed onto it for storing the remaining homogenized product and thus forming a durable, hermetical seal. 
         [0030]    In the simplified embodiment of the invention according to  FIG. 8 , the agitating element  33  according to the invention and the processing tool  11  are inserted into a cylindrical laboratory test vessel  3 . The mixing of the substance being processed again occurs without any particular measures being taken via the transportation means  47  in order to avoid an undesired pushing forward of the sample and to facilitate the overturning of the liquefied material. Additionally, in this embodiment of the invention a sieve is missing, thus there is no holding back of any non-pipettable particles from the processed substance. This embodiment of the invention is suitable for substances containing little or no parts that can be fragmented. 
         [0031]    The devices are designed for single use only and are produced preferably entirely from plastic.

Technology Classification (CPC): 1