Abstract:
The present invention relates to a centrifuge vessel assembly for use in a centrifuge, comprising a centrifuge vessel for holding a sample to be centrifuged, an adapter holding the centrifuge vessel, and a holding means holding the adapter for attaching the centrifuge vessel assembly to a rotor of the centrifuge, said centrifuge vessel having a vessel body and a sealable opening through which the sample to be centrifuged can be filled into said vessel, said vessel body having a cross-sectional area and a vessel height, said vessel height being oriented at right angles to said cross-sectional area, wherein said cross-sectional area is in the form of an oval cross-sectional area.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority under 35 U.S.C. §119 of German Patent Application No. 10 2012 013 642.0, filed Jul. 9, 2012, the disclosure of which is hereby incorporated herein by reference in its entirety. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a centrifuge vessel assembly for use in a centrifuge, comprising a centrifuge vessel for holding a sample to be centrifuged, an adapter holding the centrifuge vessel, and a holding means holding the adapter for attaching the centrifuge vessel assembly to a rotor of the centrifuge. The centrifuge vessel has a vessel body and a sealable opening through which the sample to be centrifuged can be filled into said vessel. 
       BACKGROUND OF THE INVENTION 
       [0003]    Centrifuge vessels, sample containers, and centrifuge bottles are special containers comprising a vessel body and a closable opening for use in a centrifuge. In a centrifuge, liquid mixtures, for example, are separated by implementation of high acceleration forces. To this end, a mixture to be separated is placed in a centrifuge vessel, which is then driven to rotate in such a manner that centrifugal forces within the centrifuge vessel cause separating processes to take place. By this means, individual liquids can be separated from each other or solid particles from liquids. On account of the high acceleration values, very high forces act on the centrifuge vessel and its contents, so that the centrifuge vessels must show a high degree of mechanical stability. 
         [0004]    A centrifuging process is to a certain extent time consuming. In order to reduce the time taken to process a given batch, it would be desirable to have centrifuge vessels that are of as great a capacity as possible. However, limits are set on account of the high acceleration forces that occur during centrifugation. In order to prevent the centrifuge vessels from being damaged or destroyed, use has hitherto been made of bottles having a circular cross-sectional area and a capacity of 750 milliliters. Furthermore, square type flasks of a similar capacity are presently in use, which can be employed without an adapter directly in a cup or in bottle holding means for subsequent centrifugation. Such centrifuge vessels have a greater capacity due to their corners, but they are more difficult to clean. This is a drawback, since the centrifuge vessels will often be used a number of times to save on costs. However, the cost should not be enhanced by an increased effort required for cleaning. Another disadvantage of such square type centrifuge vessels is the fact that after centrifugation residues of the sample remain in the corners and the yield of the sample is thus diminished. 
       SUMMARY OF THE INVENTION 
       [0005]    It is an object of the present invention to provide a centrifuge vessel which is capable of withstanding high acceleration values during centrifugation and at the same time has a large capacity without giving rise to cleaning problems and losses of yield. 
         [0006]    This object is achieved with a centrifuge vessel assembly for use in a centrifuge, comprising a centrifuge vessel for holding a sample to be centrifuged, an adapter holding the centrifuge vessel, and a holding means holding the adapter for attaching the centrifuge vessel assembly to a rotor of the centrifuge. Said centrifuge vessel has a vessel body and a sealable opening through which the sample to be centrifuged can be filled into said vessel. Said vessel body has a cross-sectional area and a vessel height, said vessel height being oriented at right angles to said cross-sectional area, wherein said cross-sectional area is in the form of an oval cross-sectional area. 
         [0007]    The centrifuge vessel has a cross-sectional area oriented at right angles to a vessel height of the centrifuge vessel, wherein the cross-sectional area is delimited by a closed oval curve. Thus the centrifuge vessel assembly of the present invention comprises a vessel body, which has at at least one location an oval cross-sectional area oriented perpendicularly or at right angles to a vessel height of the centrifuge vessel. The oval cross-sectional area can be formed geometrically, for example, by a cross-sectional area consisting of two semicircular areas joined together by a rectangular area. Alternatively, the oval cross-sectional area may have an elliptical shape in which the specific closed oval curve is in the form of an ellipse. 
         [0008]    Thus the cross-sectional area of the centrifuge vessel is not rotationally symmetrical, as in the prior art, and as has hitherto been avoided, since high forces occur during centrifugation which might destroy the centrifuge vessel. These forces can be kept under control when use is made of the centrifuge vessel assembly of the present invention. On account of its shape, lower forces are set free in the centrifuge vessel than is the case in a centrifuge vessel of comparable capacity but having a greater vessel height. The centrifuge vessel used in the centrifuge vessel assembly of the present invention has the advantage of making it possible to provide a vessel having a high volumetric capacity accompanied by a low overall vessel height. In this way, the prior centrifuges can still be used, since the previous overall vessel height remains unchanged. Furthermore, the centrifuge vessel of the present invention is easy to wash, since it has no corners in its bottom region, and is thus quickly reusable. Furthermore, the centrifuge vessel has no corners at the side walls or in a bottle neck, as might influence the separating results. 
         [0009]    The centrifuge vessel can be in the form of a bottle provided with an opening through which the sample to be centrifuged will be filled into the vessel. During the centrifugation process, the centrifuge vessel is sealed, for example, with a lid, which may be provided with a screw-on cap. The centrifuge vessel has, for example, a vessel body made of plastics material. Furthermore the vessel body can be fabricated as a single unit, for example, by blow molding. Moreover, the lid of the centrifuge vessel can be made of plastics material. 
         [0010]    Provision may be made for the centrifuge vessel to have a bottom surface displaying the oval cross-sectional area. This has the advantage that the centrifuge vessel will be easy to clean and that no sample residues will remain in the interior of the centrifuge vessel. 
         [0011]    In one exemplary embodiment of the centrifuge vessel of the present invention, provision may be made for a middle region of the centrifuge vessel to display the oval cross-sectional area. For this purpose, provision may additionally be made for the centrifuge vessel to have a side wall of a specific height, wherein the oval cross-sectional area remains constant over the entire height, that is to say, does not change over this entire vertical region. In this way, the centrifuge vessel will be easy to clean, since all corners have been obviated in this region. For example, the side wall is disposed in a middle region of the centrifuge vessel. 
         [0012]    In a further exemplary embodiment of the centrifuge vessel assembly of the present invention, provision may be made for the centrifuge vessel to have a conical bottom region. Such a region is advantageous, because it avoids corners, which might be a hindrance to the process of washing out the centrifuge vessel. The conical bottom region can likewise have an oval cross-sectional area that diminishes downwardly. Furthermore, provision may be made for the angle of taper to vary along the perimeter of the oval such that no corners are formed in the transition regions adjacent to any oval vertical wall. 
         [0013]    Furthermore, provision may be made for the conical bottom region to merge into a side wall that delimits the oval cross-sectional area. Thus the conical bottom region and a middle region of the centrifuge vessel can in each case be in the form of an oval cross-sectional area. 
         [0014]    For practical purposes, provision may be made for the centrifuge vessel to have a capacity of from approximately 750 milliliters to approximately 1000 milliliters. Compared with conventional centrifuge vessels, this represents an increase in capacity, which is made possible by the oval design of at least one cross-sectional area in the interior of the centrifuge vessel. By this means, the vessel height of the centrifuge vessel can remain unchanged when compared with conventional centrifuge vessels. Advantageous increases in capacity are thus obtained. The capacity of an oval vessel is, for example, equal to a gain of approximately one third over the capacity of a round bottle of identical overall vessel height. This means that in these embodiments the previous overall vessel height is retained, while the centrifuge vessels of the present invention have an enhanced capacity. 
         [0015]    The centrifuge vessel assembly of the present invention, in addition to the oval centrifuge vessel, comprises an adapter holding the vessel and a holding means holding the adapter and allowing fastening of the centrifuge vessel assembly to the rotor of a centrifuge. The centrifuge vessel assembly is preferably used in swinging bucket rotors. Fixing the centrifuge vessel assembly to the rotor can be done in any known and suitable way, such as fastening by bolts and so on. When fixed to the centrifuge rotor, the centrifuge vessel is preferably oriented such that the smaller side of the oval cross-section faces the direction of rotation. That is, the longer axis of the oval cross-section is oriented along the circumferential direction of the rotor and the fixing means, such as bolts, are preferably attached to the holding means at sites neighboring the opposing small sides of the oval centrifuge vessel. 
         [0016]    The adapter holding the centrifuge vessel preferably also has an oval cross-section and is made to follow the outer contour of the centrifuge vessel such as to support its outer surface at least in the region of its side walls. The adapter may consist of an elastic material, such as an elastomeric plastics material, which can adapt to the form of the centrifuge vessel and the holding means and can absorb at least some of the centrifugal forces and thus reduce their impact on the centrifuge vessel. 
         [0017]    The holding means is adapted to hold and support the adapter in a per se known manner and to fix the centrifuge vessel, supported by the adapter, to the centrifuge rotor. The holding means is preferably made of a rigid material, adapted in form to at least partially surround and support the outer walls of the adapter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The present invention is explained in greater detail below with reference to exemplary embodiments. However, the present invention is not restricted to these exemplary embodiments so that further combinations and applications are possible. In the schematic drawings: 
           [0019]      FIG. 1  shows a side view ( FIG. 1A ) of a first exemplary embodiment of a centrifuge vessel and a top view thereof ( FIG. 1  B); 
           [0020]      FIG. 2  shows a side view ( FIG. 2A ) of a second exemplary embodiment of a centrifuge vessel and a top view thereof ( FIG. 2B ); 
           [0021]      FIG. 3  shows the first exemplary embodiment of the centrifuge vessel as illustrated in  FIG. 1  in the mounted state; and 
           [0022]      FIG. 4  shows the exemplary embodiment as illustrated in  FIG. 3  in the demounted state of the centrifuge vessel ( FIG. 4A ), the adapter ( FIG. 4B ), and a centrifuge holder ( FIG. 4C ). 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]      FIG. 1  shows a first exemplary embodiment of a centrifuge vessel  30  in two views, of which  FIG. 1A  is a side view of the centrifuge vessel  30  and  FIG. 1B  is a top view of the centrifuge vessel  30 . The centrifuge vessel  30  comprises a vessel body  31  comprising an opening that can be sealed by means of a closure element  32  in the form of a screw-on lid. For this purpose, the lid  32  is of a circular cross-section, as shown in  FIG. 1B . 
         [0024]      FIG. 1A  shows the vessel body  31  comprising a top portion  34  located in the proximity of the opening, a middle portion  35 , and a bottom portion  36 . The top portion  34  merges continuously into the middle portion  35  by way of a first transition zone  37 , and the middle portion  35  merges continuously into the bottom portion  36  by way of a second transition zone  38 . The vessel body  31  has an oval cross-sectional area  39  in the top portion  34 , in the middle portion  35 , and in the bottom portion  36 , and the bottom portion  36  has a smaller peripheral contour than the middle portion  35 . In  FIG. 1A , the vessel body  31  comprises a side wall  45  having a wall height  46 , and the oval cross-sectional area  39  in the middle portion  35  is constant over the entire wall height  46 . 
         [0025]    The circular cross-section  33  of the lid  32 , the oval cross-section  39  of the top portion  34  and the oval cross-section of the middle portion  35  can be seen in the top view as shown in  FIG. 1B . The oval cross-section  39  of the bottom portion  36  that is smaller than the oval cross-section  39  of the middle portion  35  is hidden from view in the top view shown in  FIG. 1B  and is indicated in  FIG. 1A .  FIG. 1B  shows a longitudinal axis  40  and a transverse axis  41  that meet at a center point  42 . The oval cross-sectional areas  39  are formed mirror-symmetrically about the longitudinal axis  40  and the transverse axis  41 . The oval cross-sectional areas  39  are formed geometrically by two semicircular areas that are joined together by means of a rectangular area  43 . 
         [0026]      FIG. 2  shows a second exemplary embodiment of a centrifuge vessel  30 , in which  FIG. 2A  is a side view of the centrifuge vessel  30  and  FIG. 2B  is a bottom view of the centrifuge vessel  30 . The centrifuge vessel  30  comprises a vessel body  31  comprising an opening that can be sealed by means of a lid  32 , in this case a screw-on closure element. For this purpose, the closure element  32  is of a circular cross-section  33 . A top portion  34  of the centrifuge vessel merges continuously by way of a first transition zone  37  into a middle portion  35 . The middle portion  35  merges continuously by way of a second transition zone  38  into the bottom portion  36 . The vessel body  31  has an oval cross-sectional area  39  in its middle portion  35 . This oval cross-sectional area  39  is formed in the top portion  34  starting from the circular cross-section  33  that is in the form of a circular opening of the vessel body  31 . Furthermore, the bottom portion  36  of the vessel body  31  is of a conical shape that tapers downwardly from the oval cross-sectional area  39  in the middle portion  35  to form a conical bottom portion  36 . 
         [0027]      FIG. 2B  shows the conical bottom region  36 , as viewed from the bottom end of the vessel body  31 , which bottom end comprises a tip  45 , the center of which is aligned with the center point  42  of the oval cross-sectional area  39  in the middle portion  35 . The oval cross-sectional area  39  is delimited by an ellipsoidal perimeter, the longitudinal and transverse axes  40 ,  41  of which are shown in  FIG. 2B . 
         [0028]    Compared with the exemplary embodiment as shown in  FIG. 1 , the second exemplary embodiment as shown in  FIG. 2  does not have a flat bottom area  36  so that the centrifuge vessel shown in  FIG. 2  is placed, for example, in a supporting storage device that comprises a supporting opening and accommodates the conical portion. The centrifuge vessel  30  is retained in the supporting opening by means of the widest oval cross-section  39  in the middle portion  35 . A similar supporting means may be provided for the centrifuging process itself, which supporting means can be in the form of an adapter  50 . 
         [0029]    To summarize,  FIGS. 1 and 2  show exemplary embodiments of a centrifuge vessel  30  that is in the form of a bottle having an oval cross-sectional area  39  composed of semicircular areas ( FIG. 1 ) or in the form of an ellipse ( FIG. 2 ). Tangential transition regions adjacent to the parallel side walls  45  of the vessel body  31  are present on the bottom portion  36  in the exemplary embodiment as shown in  FIG. 1 . In the embodiment as shown in  FIG. 2 , the bottom portion  36  of the bottle  30  is conical in shape. The angle of the cone is not everywhere constant but varies with the basic shape of the bottle such that the cone terminates at the vertical surface  45  of the vessel body  31 . 
         [0030]    Both of the embodiments shown in  FIG. 1  and  FIG. 2  have the advantage that the bottle  30  allows for a sample to be easily removed from the bottom portion  36  of the bottle  30 , since corners are avoided. In both of the exemplary embodiments, the shape allows for optimization of the capacity, and at the same time of the size, of the centrifuge vessel  30 , that is to say, the bottle. The centrifuge vessel  30  does not have any corners in the bottom portion  36  and in the opening  34  or in the neck of the bottle. Thus it has now been made possible to develop rotors having maximum volume for a minimum overall diameter. The advantages of the geometry of the present invention are smaller device dimensions, less friction during rotation as compared with angled centrifuge vessels and thus reduced power consumption with an enhanced capacity of the centrifuge vessel  30 . 
         [0031]      FIG. 3  shows the first exemplary embodiment of the centrifuge vessel  30  comprising the vessel body  31  and the closure element  32 , as shown in  FIG. 1 , in the mounted state. In this case, the centrifuge vessel  30  is accommodated by an adapter  50  that is capable of being attached to a centrifuge holding means  60 . The centrifuge vessel  30  is mounted by means of the adapter  50  on the centrifuge holding means  60  so as to be rotatable during the centrifuging process, while the adapter  50  can transfer additional forces on account of its resilient properties. The holding means  60  can be fixed to the rotor of a centrifuge (not shown) at the attachment means  61  located at the small sides of the holding means. When fixed to the swinging bucket rotor of a centrifuge, the small sides of the centrifuge vessel  30 , of the adapter  50  and of the holding means  60  will face the direction of rotation, indicated by the arrow R, and the centrifuge vessel assembly will swing out via their long sides, in the direction of the arrow S. Principally, however, it would also be possible to turn the arrangement by 90° so that the holding means  60  is attached at its long sides, which face the direction of rotation, and the centrifuge vessel assembly swings out over its small side. 
         [0032]    In addition,  FIG. 4  shows the exemplary embodiment illustrated in  FIG. 3  in the demounted state, in which  FIG. 4A  shows the centrifuge vessel  30  comprising the vessel body  31  and the closure element  32 ,  FIG. 4B  shows the adapter  50 , and  FIG. 4C  shows the centrifuge holding means  60 . The adapter  50  and the holding means  60  are cup-shaped, and their inner contour corresponds to the outer contour of the parts accommodated therein. That is, the walls defining the adapter&#39;s hollow space are formed such as to support the bottom and side walls of the centrifuge vessel  30  while the walls defining the inner space of the holding means  60  surround and support the bottom and side walls of the adapter  50 . Accordingly, a centrifuge vessel  30  having relatively thin walls can be supported in the centrifuge vessel assembly of the present invention. 
         [0033]    While the present invention has been illustrated by description of various embodiments and while those embodiments have been described in considerable detail, it is not the intention of Applicants to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications will readily appear to those skilled in the art. The present invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of Applicant&#39;s invention.