Abstract:
A device for mixing and homogenizing materials, especially infectious or chemically aggressive materials, which can be inserted into a laboratory test container. A disposable lid is provided to hermetically seal said laboratory test container. A stirring element is provided in the disposable lid for processing the material that is introduced into the laboratory test container. Said stirring element is fitted with a cutting element that rotates about the longitudinal axis of the laboratory test container, said cutting element processing the material together with additional cutting edges. Complete homogenization of tissue fragments can be securely achieved by hermetically closing the laboratory test container.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a device for mixing and homogenizing materials, in particular infectious or chemically aggressive materials, in a laboratory test container. 
     2. Description of the Related Art 
     Magnetic stirrers and mechanical stirrers are generally known and customary in laboratory operation. During the comminution of infectious or chemically aggressive materials in containers which are not hermetically sealed, there is a high risk of infection and/or contamination as a result of uncontrolled splashes, which can penetrate to the outside through the opening of the laboratory test container, as a result of inadvertently tipping over the laboratory test container and as a result of the use of repeated-use mixers. This is the case in particular in the case of test tubes and mixers known for this purpose. 
     On the basis of this prior art, it is an object of the present invention to provide a device of the type mentioned at the beginning which permits hermetic sealing of the laboratory test container and complete, thorough mixing of miscible substances and liquids. 
     SUMMARY OF THE INVENTION 
     The invention, provides for a device for mixing and homogenizing materials, in particular infectious or chemically aggressive materials, in a laboratory test container with a stirring element. The device comprises a lid to seal the laboratory test container hermetically. The stirring element is provided in the lid to process the material that can be introduced into the laboratory test container. A cutting element is also provided in the lid, wherein the cutting element rotates about a longitudinal axis of the laboratory test container and which is arranged in the immediate vicinity of farther cutting edges. 
     The fact that a lid is provided, with which, at the same time, the laboratory test container is sealed hermetically and materials in the laboratory test container are processed, in particular mixed and homogenized, means that the working safety of the user performing the processing is increased significantly. This means that infectious tissue fragments can also be handled safely. As a result of the hermetic sealing of the laboratory test container, complete homogenization of the tissue fragments can thus be achieved in a safe way. 
     The lid is advantageously configured as a disposable lid, so that it is disposed of immediately after use and thus contamination during further work in the laboratory is reliably avoided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in more detail below using various exemplary embodiments and with reference to the appended drawings, in which: 
         FIG. 1  shows a schematic, partly sectioned lateral view of a first exemplary embodiment of the invention, 
         FIG. 2  shows a schematic plan view of the disposable lid of the first exemplary embodiment according to  FIG. 1 , 
         FIG. 3  shows an illustration of the disposable lid from  FIG. 1 , 
         FIG. 4  shows an exploded illustration of the drive from  FIG. 1  used in the disposable lid, 
         FIG. 5  shows a schematic, partly sectioned lateral view of a second exemplary embodiment of the invention, 
         FIG. 6  shows a schematic plan view of the disposable lid of the second exemplary embodiment according to  FIG. 5 , 
         FIG. 7  shows an illustration of the disposable lid from  FIG. 5 , 
         FIG. 8  shows an exploded illustration of the drive from  FIG. 5  used in the disposable lid, 
         FIG. 9  shows a schematic, partly sectioned lateral view of a third exemplary embodiment of the invention, 
         FIG. 10  shows a schematic plan view of the disposable lid of the third exemplary embodiment according to  FIG. 9 , 
         FIG. 11  shows an illustration of the disposable lid from  FIG. 9 , 
         FIG. 12  shows a schematic, sectioned view of a disposable lid according to a fourth exemplary embodiment of the invention, and 
         FIG. 13  shows a plan view of the disposable lid from  figure 12 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a schematic, partly sectioned lateral view of a first exemplary embodiment of the invention. A laboratory test container is provided with the reference symbol  20 . In this case, this is a small cylindrical tube  18  with a conically tapering point  21 . The interior  17  of the laboratory test container  20  is filled with the materials  37  to be mixed. The laboratory test container  20  is then sealed with the disposable screw-closure lid  10  in the use of the latter and then inverted. 
     Provided in the disposable screw-closure lid having a tube portion and a cap portion or disposable snap-action cap (snap cap)  10  of the hermetically sealable laboratory test container  20  is an inserted, four-edged plastic or metal bar  11  provided with radial and axial cutting edges  29 , which is led past the cutting edges  28  of the cutting ribs  12  provided on an inner surface of the tube portion. This bar  11  is driven from outside the laboratory test container  20  with the aid of the shaft  13  by an internal-hexagon quick coupling ring  14 . 
     The laboratory test container  20  with the materials to be mixed and homogenized is placed on an external drive with a force fit via the coupling ring  14  with the inverted container position corresponding to  FIG. 1 . By means of the transmitted rotational movement, the substances and liquids in the interior  17  of the container  20  are sucked in axially by the bar  11 , that is to say along the longitudinal axis  22  of the laboratory test container  20 , and thrown out radially. In the process, under the cutting action at the peripheral cutting ribs  12 , they are expelled through the slots. As a result, the material to be mixed is squeezed, mixed, homogenized and subsequently deflected upward at the mixer wall  15 , which in each case extends between the cutting ribs  12 . The sealing ring  16  placed around the shaft  13  prevents the liquid running out. The rotational energy is transmitted mechanically to the bar  11  from outside to the coupling ring  14  and the shaft  13 . The rotational speed is defined specifically to the material for optimum homogenization. The sealing ring  16  can be implemented by means of a sealing lip. 
       FIG. 2  shows a schematic plan view of the disposable lid  10  of the first exemplary embodiment according to  FIG. 1 . Identical features are provided with the same reference symbols in all the figures. The cutting lips  12  are formed by an element arranged in a wave shape on the circumference, which here comprises nine lips. The bar  11  can, for example, be formed in a U shape, open at the bottom, so that there are two vertical cutting edges  29  on both sides of the bar  11 . These respectively two cutting edges  29  are at a short distance opposite the cutting edges  28 , eighteen here (two times nine), of the cutting lips  12 . 
       FIG. 3  shows an isolated representation of the disposable lid  10  from  FIG. 1 , in which all the elements essential for the transmission of the rotational movement have been inserted into the body  3 .  FIG. 4  shows an exploded illustration of the drive from  FIG. 1  used in the disposable lid  10 , comprising the bar  11  with shaft  13  connected in one piece, the sealing ring  16  and the coupling ring  14 , which are all arranged around the longitudinal axis  22  of the device. 
       FIG. 5  shows a schematic, partly sectioned lateral view of a second exemplary embodiment of the invention. The disposable lid  10  has a body  3  defining a cylindrical tube portion having a first end and a second end and a cap portion which has a circumferential groove  24 , between the tube portion and the cap portion into which the laboratory test container  20  can be plugged or screwed. The first end of the tube portion is attached to the cap portion and extends from the first end to the second end away from the cap portion, wherein the container  20  is received within the groove  24  whereby the tube portion extends a distance within the container  20  and abuts against an interior  9  of the laboratory test container. On the inner side of the circumferential groove  24 , a sealing element  1  is inserted, which simultaneously seals off the interior  9  of the laboratory test container  20  hermetically with respect to the outside. The sealing element  1  simultaneously has a perforated disk which is arranged transversely with respect to the longitudinal axis  22  and which forms a cavity  30 , which forms a cylindrical cage or tube portion, with respect to the body  3 . Arranged in this cavity  30  is a spider  2 . The spider  2  has radial  39  and peripheral  38  cutting edges provided between the first end and the second end of the tube portion, which are led past the corresponding cutting edges  31  of the inlet holes  25 . The laboratory test container  20  with the materials to be mixed is then sealed by the disposable lid  10 , inverted and placed on the external drive with a force fit via the drive shaft  4  and the connection  6 . A sealing lip  5  prevents the liquid running out. The rotational energy is transmitted mechanically to the bar  11  from outside to the coupling ring  14  and the shaft  13 . The rotational speed is defined specifically to the material for optimum homogenization. The sealing ring  16  can be implemented by means of a sealing lip. 
       FIG. 6  shows a schematic plan view of the disposable lid of the second exemplary embodiment according to  FIG. 5 . In the disk region, the sealing element  1  here has four apertures  25 , which have a radial spacing from the shaft  22  and are arranged with an angular spacing of 90 degrees in relation to one another. Here, the cutting element is a spider  2  having four arms  32 . Instead of four apertures  25  and one spider  2  with four arms  32 , corresponding elements with three or, for example, five apertures/arms are also possible. The spider  2  can be a four-edged plastic cross. 
       FIG. 7  shows an illustration of the disposable lid from  FIG. 5 . 
       FIG. 8  shows an exploded illustration of the drive from  FIG. 5  used in the disposable lid  10 , which drive comprises the four elements. In this case, the reference symbol indicates that the laboratory test container  20  is screwed into the circumferential groove, which has an appropriate thread  33  on its outer side. 
     In particular, the drive shaft  4  can be thermally conductive, so that thermal energy can be introduced into the laboratory test container  20  or dissipated to the outside from the latter via this drive shaft  4 . Provision can also be made for electrical energy to be introduced into the laboratory test container  20  via the drive shaft  4  and/or for electrochemical sensors to be used. 
       FIG. 9  shows a schematic, partly sectioned lateral view of a third exemplary embodiment of the invention. A rotary vane or rotor  13  in a cylindrical cage  42  is integrated into the lid  10 . The cylindrical cage  12  is inserted into a body  41  of the lid  10  and has four radially oriented, oval apertures  26 , through which the material to be homogenized is guided into the cavity  30  in the cage  42  and is cut there by the rotor  13 . 
     The inert rotor  13 , which can be formed by a bar magnet  43  or comprises the latter as a core, has radial  39  and peripheral  38  cutting edges, which are led past the corresponding cutting edges  31 , that is to say the edges of the openings  26 , of the cylindrical cage  42 . The laboratory test container  20  with the tissue material  27  is put into the drive standing on the lid, so that the result is a filling level  37  and the material is in contact with the cage  42  and the rotor  13 . The known drive, not illustrated in the drawings, comprises a further magnetic rotor, with which the rotational energy is transmitted magnetically or electromagnetically. The magnetic field strength is dimensioned such that a torque which is optimal for the homogenization is transmitted. 
       FIG. 10  shows a schematic plan view of the disposable lid  10  of the third exemplary embodiment according to  FIG. 9 , and  FIG. 11  shows an illustration of the disposable lid from  FIG. 9 . The circular groove  24  permits the laboratory test container  20  to fit in the lid  11  with a fit which goes beyond a form fit. The magnetic bar  13  is constructed asymmetrically, so that by means of the fluidically optimized construction, in one direction of rotation, a central liquid stream from top to bottom [lacuna] produced and, in the other direction of rotation, a lateral liquid stream along the wall of the laboratory test container  20  from top to bottom [lacuna] produced. The suction and expulsion action is thus changed by means of a reversal of the direction of rotation. 
       FIG. 12  shows a schematic, sectioned lateral view of a disposable lid according to a fourth exemplary embodiment of the invention, and  FIG. 13  shows a plan view of the disposable lid from  FIG. 12 . In addition, the connection is also illustrated here. The differences from the exemplary embodiment from  FIG. 1  are, in particular, as follows. The quick coupling ring  14  has teeth on its underside, which engage in teeth  53  belonging to a drive shaft  54 . The bottom edge  55  of the body  3  is in particular drawn downward to such an extent that the lid  10  can be put in place flat without the teeth of the quick coupling ring  14  protruding. 
     A ball bearing for the shaft  13  is designated by the reference symbol  59 . However, such a ball bearing is not necessary for cost-effective fabrication of the device as a disposable lid  10 . It can in particular be replaced by a sliding mounting of the drive shaft  13 , not illustrated in the drawings, the sealing being provided by an inserted O-ring. This is advantageous in particular since, in the case of a disposable lid  10 , the bearing is loaded and must withstand this load only once and then for only a short time. 
     Here, the cage  52  simultaneously forms cutting edges, which do not consist of apertures as in the second exemplary embodiment, nor of a purely lateral element as in the first exemplary embodiment. The cage  52  has lugs  56  which are drawn downward and embrace the bar  11 . The latter is equipped with two arms, but a spider  2  with more arms can also be provided. The cutting edges  57  can be seen in particular in the plan view of  FIG. 13 , cavities  58  are [sic] adjacent lugs  56  picking up material in order then to cut it off with the bar  11 . 
     Not illustrated in the drawings are the following features, which can be accommodated in all the embodiments illustrated in the figures. Beside the bar, for example in the region  60  and  61  in  FIG. 12 , sensor lines can be led through the body  3  and have electrical connections on the side pointing outward. Thus, during mixing, a sensor can be arranged in a straightforward manner in the vicinity of the bottom of the material to be processed. Instead of sensor lines, an optical conductor can also be led through, or a feed line which forms a heating body or a Peltier element in the interior  60 .