Abstract:
Disclosed is a centrifuging device with a detachable cover and a safeguard structure in which the cover of the centrifuging device can be completely separated from the housing; and the safeguard structure can prevent a rotor from becoming separated from a drive shaft during operation due to flange defection and prevent the fractured pieces of the rotor from springing out of the housing when the rotor breaks or cracks. The centrifuging device according to the invention offers ease of cleaning and improved safety. Furthermore, there is no need to worry about the fracture of a coupling portion between the cover and the housing attributable to the repeated opening and closing.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims priority to Korean Patent Application No. 10-2008-0098572, filed Oct. 8, 2008, which application is incorporated by this reference in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a centrifuging device, and more particularly to a centrifuging device with a detachable cover and a safeguard structure in which the cover of the centrifuging device can be completely separated from the housing; and the safeguard structure can prevent a rotor from becoming separated from a drive shaft during operation due to flange defection and prevent a fractured pieces of the rotor from springing out of the housing when the rotor breaks or cracks. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, a centrifuging device is used for separating a specified component from a mixture of a variety of components having different densities or phases using centrifugal force. 
         [0006]    The centrifuging device primarily includes a housing and a cover. The housing accommodates a cylindrical rotor with a plurality of hollow cavities for receiving sample tubes and a driving unit for rotating the rotor at high speeds. The cover is an element for separating the inside space of the housing (in which the rotating rotor is accommodated) from the outside and is an essential element for preventing a sample (mixture) from flying off and intrusion of external foreign matter into the housing. 
         [0007]    A plurality of sample tubes containing a sample to be centrifugally separated are inserted into the hollow cavities in the rotor, and centrifugation starts by rotation of the rotor with sample tubes at a high speed in the housing by the driving unit. Through these steps, the sample contained in each sample tube may be centrifugally separated. 
         [0008]    Generally, the cover is directly connected to the housing by a hinge. Accordingly, to insert sample tubes into hollow cavities in the rotor for centrifugal separation and to removing sample tubes from the rotor after a centrifugal separation process is finished, an operator exposes the housing by pivoting the cover. 
         [0009]    Conversely, to perform the centrifugal separation, i.e. to rotate the rotor to which the sample tubes are inserted, the operator closes the housing by pivoting the cover about the hinges. By such operations, the inside and outside of the housing is demarcated. 
         [0010]    Owing to the cover being connected directly in a fixed manner to the housing, the following problems occur. 
         [0011]    Since the cover is fixed to an end of the housing in a pivoting manner, it is difficult to clearly wash the cover. That is, when a sample comes to stick to the surface of the cover or the housing due to the scattering of the leaking sample fluid from the sample tube by centrifugal force, perfect cleaning the housing and the cover is difficult because the cover can not be completely separated from the housing in the known centrifuging device. Above all, it is difficult to perfectly clean the hinge. Accordingly, the centrifuging device may become severely contaminated. 
         [0012]    Another problem of the known centrifuging device is that the connection part between the cover and the housing easily becomes broken due to the repeated opening and closing, which results in a shortened lifespan of the centrifuging device. 
         [0013]    According to the known centrifuging device, additional connection means capable of cooperating with the hinge manner is needed to securely connect the cover to the housing. 
         [0014]    Because the cover cannot be completely separated from the housing due to the hinge, the operator must hold the cover when inserting the sample tubes into or removing the sample tubes from the rotor. It is inconvenient. 
         [0015]    The rotor of the centrifuging device may be separated from a drive shaft during operation due to the defection of the flange. Moreover, the fractured pieces of the rotor are likely to spring out of the housing of the centrifuging device in the case when the rotor breaks or cracks. Such accidents actually occur, which bring about a severe dangerous situation. Accordingly, an effort and means for preventing the above safety problems is needed. However, a centrifuging device capable of solving such problems has not been developed yet. 
       SUMMARY OF THE INVENTION 
       [0016]    The invention is made in view of the above-mentioned problems and an object of the invention is to provide a centrifuging device with a detachable cover and a safeguard structure in which the cover of the centrifuging device can be completely separated from the housing; and the safeguard structure can prevent a rotor from becoming separated from a drive shaft during operation due to flange defection and prevent a fractured pieces of the rotor from springing out of the housing when the rotor breaks or cracks. 
         [0017]    According to one aspect of the invention, there is provided a centrifuging device including a housing composed of a lower and middle housing in which a driving unit is accommodated, and an upper housing with a safeguard structure for preventing a rotor from becoming separated from a drive shaft during operation due to flange defection and the fractured pieces of the rotor from springing out of the housing when the rotor breaks or cracks, in which a lower portion of the rotor is installed in a manner such that a lower portion of the rotor can rotate; wherein a rotor with a plurality of hollow cavities for receiving sample tubes; and wherein a cover which is attached to the housing can be completely separated from the housing and separate the rotor from the outside. 
         [0018]    In the centrifuging device, it is preferable that the housing be composed of a lower housing and a middle housing accommodating a driving unit therein, and an upper housing accommodating a lower portion of the rotor connected to the drive shaft. The upper housing is composed a ring-shaped metal plane portion capable of preventing the rotor and the fractured pieces of the rotor from springing out of the housing, and the connection part between the upper housing and the middle housing. The ring-shaped metal plane portion extends inward from an inside surface of the upper housing and has an inner diameter smaller than a diameter of the lower portion of the rotor for functioning as a safeguard structure. 
         [0019]    In the centrifuging device, it is preferable that a plurality of magnets be fixed to a lower end portion of the cover so that the cover is coupled to the ring-shaped plane portion of the upper housing by magnetic force when the cover is placed on the upper housing. Accordingly, the ring-shaped plane portion must be made of a metal so that the cover and the ring-shaped plane portion can be coupled to each other by the magnetic force. 
         [0020]    In the centrifuging device, it is preferable that the upper housing have an extension portion extending upward from an inner edge of the ring-shaped plane portion of the upper housing, in which the extension portion has an internal circumferential surface corresponding to the surface of the rotor and an external circumferential surface corresponding to the internal circumferential surface of the lower end portion of the cover. 
         [0021]    In the centrifuging device, it is preferable that the extension of the ring-shaped plane portion of the upper housing have a ring shape extending over the entire length of the inner edge of the ring-shaped plane portion, or be composed of a plurality of unit pieces arranged along the entire length of the inner edge of the ring-shaped plane portion while having a predetermined gap between each of them. 
         [0022]    In the centrifuging device, the upper housing provides a safeguard structure which can prevent the rotor and the fractured pieces of the rotor from springing out of the housing. However, this structure is just an embodiment. That is, it is possible to obtain the same advantage by coupling a third part having a safeguard structure to the upper housing. 
         [0023]    The centrifuging device according to the invention has advantages in that the cover can be completely separated from the housing so that the cover and the housing can be conveniently washed and has another advantage in that fracture of a coupling portion between the cover and the housing, which frequently occurs in the known centrifuging device attributable to the repeated opening and closing, is not likely to occur. 
         [0024]    Further, according to the invention, it is possible to prevent the rotor from becoming separated from the drive shaft during operation due to the defection of the flange, and to prevent the fractured pieces of the rotor from springing out of the housing when the rotor cracks or breaks. Accordingly, the centrifuging device according to the invention offers dramatically improved safety in comparison with the known centrifuging device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: 
           [0026]      FIG. 1  is a perspective view illustrating a centrifuging device according to one embodiment of the invention; 
           [0027]      FIG. 2  is a sectional view illustrating a housing of the centrifuging device, part of which is cut off according to the embodiment of the invention; and 
           [0028]      FIG. 3  is a perspective view illustrating a coupling state of a cover and the housing which constitutes the centrifuging device shown in  FIG. 1  and  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    Reference will now be made in greater detail to exemplary embodiments of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts. 
         [0030]    Hereinafter, centrifuging devices according to embodiments of the invention will be described with reference to the accompanying drawings. 
         [0031]      FIG. 1  is a perspective view illustrating a centrifuging device according to one embodiment of the invention, and  FIG. 2  is a sectional view illustrating the centrifuging device of  FIG. 2 , part of which is cut off. 
         [0032]    With reference to  FIG. 1  and  FIG. 2 , the centrifuging device  10  according to one embodiment of the invention includes a housing  200  having a hollow body, and a hemispherical cover  100  coupled to an upper portion of the housing  200 . 
         [0033]    A driving unit  250  and a rotor  240  connected to the drive shaft  251  of the driving unit  250  are installed in the housing  200 . The rotor  240  has a conical shape and the center portion of the rotor  240  is connected to the drive shaft  251  of the driving unit  250 . The inner circumferential surface of the rotor  240  has a plurality of hollow cavities  241  for receiving sample tubes. 
         [0034]    Each of the hollow cavity  241  is a hole having a predetermined depth and can receive a tube (not shown) containing a sample therein. 
         [0035]    A reference  252  denotes a flange provided at an upper end portion of the drive shaft  251  and functions to prevent the rotor  240  from becoming separated from the drive shaft  251 . 
         [0036]    The housing  200  includes a cylindrical lower housing  210 , a middle housing  220  connected to the lower housing  210  and having a space for accommodating the driving unit  250  therein, and an upper housing  230  which receives a lower portion of the rotor  240  and is coupled to the cover  100 . The upper housing  230  has a safeguard structure which is the feature of the invention. Accordingly, the driving unit  250  is placed in the lower housing  210  and the middle housing  220 . Particularly, the lower portion of the rotor  240  is accommodated in the upper housing  230 , and an upper portion of the rotor  240  protrudes from an upper end portion of the upper housing  230  through a ring-shaped opening portion and is exposed to air. 
         [0037]    The upper housing  230  has a ring-shaped opening external circumferential plane portion  232  which functions as a safeguard structure and has an inner diameter smaller than a diameter of the lower portion of the rotor  240 . The upper housing  230  has a connection part  231  for connecting the upper housing  230  to the middle housing  220 . The upper housing  230  and the middle housing  220  are connected to each other via the connection part  231 . When connecting the upper housing  230  and the middle housing  220  to each other, connecting means, such as a bolt and nut is used, but the connecting means may not be limited thereto. The ring-shaped opening external circumferential plane portion  232  is called a ring-shaped plane portion. 
         [0038]    The ring-shaped plane portion  232  which is the safeguard structure of the upper housing  230  and which has a diameter smaller than the diameter of the lower portion of the rotor  240  for preventing the rotor  240  from becoming separated form the drive shaft  251  during operation due to the defection of the flange  252  and for preventing the fractured pieces of the rotor  240  from springing out of the housing  200  of the centrifuging device when the rotor  240  breaks or cracks. The ring-shaped plane portion  232  is a portion at which a lower portion of the cover  100  is placed and at which coupling between the cover  100  and the housing  200  is achieved by the action of magnetism. Accordingly, the ring-shaped plane portion  232  is preferably made of a metal. 
         [0039]    The upper housing  230  may further include an extension portion  233  which extends upward from an inner edge of the ring-shaped plane portion  232  in addition to the ring-shaped plane portion  232  and the connection part  231 . 
         [0040]    The extension portion  233  formed at the inner edge of the ring-shaped plane portion  232  has a predetermined height, and an internal circumferential surface of the ring-shaped plane portion  232  corresponds to an external circumferential surface of the rotor  240 .  FIG. 2  shows that the ring-shaped extension portion  233  is formed of a single member continuously extending over the entire length of the inner edge of the ring-shaped plane portion  232 , but the invention is not limited thereto. For example, the extension portion  233  may be composed of a plurality of unit pieces which is arranged along the entire length of the inner edge of the ring-shaped plane portion  232  with a predetermined gap between each of them. 
         [0041]    The cover  100  is composed of a hemispherical elementary part  101  of which a lower end is open, a handle  102  provided at an upper portion of the elementary part  101 , and a plurality of magnets  104  installed at a lower end portion of the cover  100 . The outer circumferential surface of the lower end of the hemispherical elementary part  101  is provided with a plurality of concave portions  103 , each concave portion  103  having a bottom extending inward and sides extending downward. Magnets  104  are fixed to the bottoms of the concave portions  103 . 
         [0042]    Functions of the centrifuging device composed of the housing  200  including the upper housing  230  having the above-mentioned safeguard structure, along with those of the cover  100 , will be described with reference to the drawings. 
         [0043]      FIG. 3  is a perspective view illustrating a coupling state of a cover  100  and the housing  200  which constitute the centrifuging device shown in  FIG. 1  and  FIG. 2 . 
         [0044]    An operator inserts the sample tubes (not shown) into the hollow cavities  241  of the rotor  240  placed in the housing  200  and then places the cover  100  on top of the housing  200 . 
         [0045]    That is, the lower end portion  101 - 2  of the hemispherical elementary part  101  of the cover  100  and the bottoms of the concave portions  103  are placed on the ring-shaped plane portion  232  of the upper housing  230 , and the cover  100  is attached to the ring-shaped plane portion  232  made of a metal by the magnetic force of the magnets  104  fixed to the bottoms of the concave portions  103 . 
         [0046]    The operator rotates the rotor  240  by driving the driving unit  250  through a control panel  260  attached to the housing  200 . Therefore the samples in the sample tubes inserted in the hollow cavities  241  of the rotor  240  are centrifugally separated by the centrifugal force. 
         [0047]    After completion of the centrifugal separation process, the operator can completely separate the cover  100  from the housing  200  (see  FIG. 2 ) by lifting the cover  100  with the force which is stronger than the coupling force between the magnets  104  fixed to the cover  100  and the ring-shaped plane portion  232 . 
         [0048]    In the state of  FIG. 2  in which the cover  100  is completely separated from the housing  200 , the operator can easily remove the sample tubes inserted in the hollow cavities  241  of the rotor  240  and insert new sample tubes in the hollow cavities  241  of the rotor  240 . Further, it is easy to wash and remove the sample which leaks from the sample tubes during the centrifugal separation process and sticks to the cover  100 . 
         [0049]    On the other hand, the cover  100  is fixed onto the ring-shaped plane portion  232  of the upper housing  230  only by the magnetic force of the magnets  104 . Accordingly, in the case in which unexpected external force stronger than the magnetic force is exerted on the hemispherical cover  100 , the cover  100  is likely to shake on the upper housing  230 . 
         [0050]    In the case in which the cover  100  shakes in a certain direction by the external force occurring in the middle of the centrifugal separation process, i.e. while the rotor  240  is rotating in the upper housing  230 , the cover  100  is likely to be brought into contact with the rotor  240 , which may severely affect the rotation of the rotor  240  and may cause the cover  100  to break or to be separated from the centrifuging device  10 . 
         [0051]    To prevent such an accident from occurring, the extension portion  233  having a predetermined height is formed at the inside edge (facing the rotor  240 ) of the ring-shaped plane portion  232  of the upper housing  230  in which the lower end portion of the cover  100  is placed. 
         [0052]    The outer circumferential surface of the extension portion  233  is arranged facing the inner circumferential surface of the lower end of the hemispherical cover  100 . Accordingly, in the case in which the cover  100  is shaking in a certain direction by the external force applied to the cover  100  while the rotor  240  is rotating in the upper housing  230 , the lower end portion of the cover  100  and the extension portion  233  are brought into contact with each other, and movement of the cover  100  is suppressed. 
         [0053]    In other words, the cover  100  and the rotor  240  which is rotating may not be in contact with each other due to the extension portion  233  so that the cover  100  does not break and rotation of the rotor  240  is not obstructed. For such a reason, the centrifugal separation may stably continue. 
         [0054]    The invention is not limited to the above-mentioned embodiments but may be embodied in various forms. The above-mentioned embodiments are provided to help ordinary skilled people better understand the scope of the invention. Accordingly, the scope of the invention must be understood from the following claims. 
         [0055]    Although exemplary embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.