Patent Publication Number: US-2009236248-A1

Title: Case Unit

Description:
TECHNICAL FIELD 
     The present invention relates to a case unit for storing an analytical tool for analyzing a sample such as blood or urine or other articles in hygienic conditions. 
     BACKGROUND ART 
       FIGS. 8A ,  8 B,  9 A and  9 B show examples of conventional case unit for storing an analytical tool (see  FIGS. 2A-2C ,  3 A- 3 C,  14 A and  14 B of International Publication WO2006/046701). 
     The case unit  9 A shown in  FIG. 8A  includes a case  90  for storing an analytical tool. The case  90  has a front surface formed with a take-out opening  91 . A cover  93 , which is in threading engagement with a screw shaft  92 , is mounted to the case  90 . The cover  93  is movable in the axial direction of the screw shaft  92  by rotating around the screw shaft  92 . The cover  93  includes a sealing portion (not shown) made of an elastic material. As shown in  FIG. 8B , when the sealing portion faces the take-out opening  91  as a result of the rotation of the cover  93  in the arrow N 10  direction, the take-out opening  91  is closed. In this state, the interior of the case  90  is hermetically closed, so that moisture or dust is prevented from entering the case  90 . 
     The case unit  9 B shown in  FIG. 9A  includes a case  94  for storing a plurality of analytical tools  99 . The case  94  is open at the upper end. A cover  95  including a head  95   a  in the form of a cap is mounted to the case  94 . The cover  95  further includes a cylindrical portion  95   b  which is slidable vertically by rotating relative to the case  94 . The cylindrical portion  95   b  is formed with a take-out opening  96 . When the cylindrical portion  95   b  is moved downward, the take-out opening  96  enters the case  94  to be closed. In this state, the upper opening of the case  94  is closed with the head  95   a,  as shown in  FIG. 9B . Thus, the interior of the case  94  is hermetically closed, so that moisture or dust is prevented from entering the case  94 . 
     However, the above-described conventional structures have the following drawbacks. 
     In the case unit  9 A, when the sealing portion of the cover  93  is positioned to face the take-out opening  91 , the sealing portion needs to be pressed strongly against the front surface of the case  90  to reliably provide hermetic sealing of the case  90 . However, for the smooth rotation of the cover  93 , it is desirable that the sealing portion of the cover  93  is not strongly pressed against the front surface of the case  90  when the sealing portion does not face the take-out opening  91 . The cover  93  is in threading engagement with the screw shaft  92  and moves forward or rearward by the distance corresponding to the angle of rotation when it is rotated. Thus, it is difficult to set the cover  93  in such a manner that the sealing portion is to be strongly pressed against the front surface of the case  90  only when the sealing portion faces the take-out opening  91  as a result of the rotation of the cover through a predetermined angle and properly maintain the setting for a long period of time. Further, when the sealing portion is worn out, the sealing performance deteriorates. 
     In the case unit  9 B, on the other hand, the inner diameter of the cylindrical portion  95   b  of the cover  95  needs to be made larger than the length or width of the analytical tool  99 . Further, since the case  94  needs to accommodate the cylindrical portion  95   b  of the cover  95  slidably and rotatably, the case  94  also needs to be made large correspondingly to the cover  95 . Thus, the case unit  9 B is not suitable for reduction in size and weight. 
     DISCLOSURE OF THE INVENTION 
     An object of the present invention is to provide a case unit which is capable of reducing or alleviating the problems described above. 
     According to the present invention, there is provided a case unit comprising a case for storing an article which includes a front surface formed with a take-out opening through which the article is to be taken out of the case, a cover including a sealing portion for closing the take-out opening, and guiding means for enabling the cover to slide relative to the case so that the sealing portion moves reciprocally in a first and a second directions along the front surface. When the sealing portion is moved in the first direction from a position spaced from the take-out opening to a position in front of the take-out opening, the guiding means displaces the sealing portion toward the front surface so that the sealing portion is pressed against a periphery of the take-out opening. 
     The orientation and posture of the case of the case unit may be varied in many ways. In the present invention, the front and the rear of the case are determined based on the surface formed with the take-out opening. Thus, when the case has a plurality of surfaces, the surface region formed with the take-out opening is the front surface of the present invention regardless of in which directions the surfaces are oriented. 
     Preferably, the periphery of the take-out opening is formed as a tapered surface which is inclined to project forward from the front surface in such a manner that the projecting amount increases as proceeding in the first direction. In closing the take-out opening, the sealing portion is pressed against the tapered surface. 
     Preferably, when the sealing portion is spaced from the take-out opening, the guiding means keeps the surface of the sealing portion inclined with respect to the front surface. When the sealing portion is moved to a position in front of the take-out opening to close the take-out opening, the guiding means rotates the cover so that the surface of the sealing portion becomes parallel with the periphery of the take-out opening. 
     Preferably, when the sealing portion is spaced from the take-out opening, the guiding means keeps the surface of the sealing portion inclined at an angle of inclination which is larger than the angle of inclination of the tapered surface. When the sealing portion is moved to a position in front of the take-out opening to close the take-out opening, the guiding means rotates the cover so that the surface of the sealing portion becomes parallel with the tapered surface. 
     Preferably, the guiding means includes a guide groove provided at one of the case and the cover, and a guide projection provided at the other one of the case and the cover and received in the guide groove. The movement path of the guide projection is defined by the guide groove. 
     Preferably, the case includes a pair of side surfaces at each of which the guide groove is formed, whereas the cover includes a pair of side walls which face the paired side surfaces and at each of which the guide projection is formed. The guide groove includes a front inner wall and a rear inner wall facing each other and extending in the first and the second directions. The front inner wall is formed with a projecting wall portion projecting toward the rear end of the case. When the sealing portion is moved to a position in front of the take-out opening, the guide projection is guided toward the rear end of the case by the projecting wall portion so that the sealing portion is pressed against the periphery of the take-out opening and maintains the pressed state. 
     Preferably, the guide projection extends in the longitudinal direction of the guide groove. When the sealing portion moves while being spaced from the take-out opening, at least longitudinally opposite ends of the guide projection are held in contact with one of the front inner wall and the rear inner wall, whereas a longitudinally intermediate portion of guide projection is held in contact with the other one of the front inner wall and the rear inner wall, so that posture of the cover is substantially maintained. 
     Preferably, the projecting wall portion is provided at a position spaced from the take-out opening in the first and the second directions. When the guide projection is guided by the projecting wall portion to be displaced toward the rear end of the case, the cover rotates so that the sealing portion is pressed against the periphery of the take-out opening. 
     Preferably, the article to be stored in the case is an analytical tool used for analyzing a sample. The case unit further comprises positioning means provided in the case for supporting a plurality of analytical tools stacked in a thickness direction of the tools and positioning the analytical tools so that the analytical tool at an end of the stack faces the take-out opening. The case and the cover are structured as an analytical tool cartridge. 
     Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing an example of case unit according to the present invention; 
         FIG. 2  is an exploded perspective view of the case unit shown in  FIG. 1 ; 
         FIG. 3  is a sectional view taken along lines III-III in  FIG. 1 ; 
         FIG. 4  is a sectional view taken along lines IV-IV in  FIG. 3 , showing the internal structure of the case  1  with partial omission; 
         FIG. 5A  and  FIG. 5B  are sectional views showing the sliding operation of the cover of the case unit shown in  FIG. 1 ; 
         FIG. 6  is a sectional view showing the case unit of  FIG. 1  in the state in which the take-out opening is closed; 
         FIG. 7A  is a cross sectional view showing another example of case unit according to the present invention,  FIG. 7B  is a longitudinal sectional view of the case unit, and  FIG. 7C  is a longitudinal sectional view of the case unit shown in  FIG. 7B  in the state in which the take-out opening is closed; 
         FIG. 8A  and  FIG. 8B  are perspective views showing an example of conventional structure; and 
         FIG. 9A  and  FIG. 9B  show another example of conventional structure. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. 
       FIGS. 1-6  show an example of case unit according to the present invention. As shown in  FIGS. 1 and 2 , the case unit C 1  of this embodiment includes a case  1  including a front surface  11  formed with a take-out opening  19 , and a cover  2 . The cover  2  is slidable along the case  1  in the vertical direction indicated by the arrows D 1  and D 2 . The downward direction D 1  is an example of first direction of the present invention. The upward direction D 2  is an example of second direction of the present invention. 
     The case unit C 1  is designed to be used in combination with e.g. an analytical apparatus A illustrated by phantom lines in  FIG. 1 . The analytical apparatus A is designed to perform measurement of blood glucose level in blood or other kinds of analysis when an analytical tool  8 , which will be described later, is inserted into a predetermined portion of the analytical apparatus A and blood is applied to the analytical tool  8 . The case unit C 1  stores a plurality of analytical tools  8  to be used for such analysis (see  FIGS. 3 and 6 ). 
     The case  1  may be made of a relatively hard synthetic resin. As shown in  FIG. 2 , the case  1  includes a main portion  10  which is generally in the form of a prism extending in the vertical direction and an auxiliary portion  14  extending forward from a lower part of the main portion  10 . The main portion  10  includes the front surface  11 , a rear surface  13  and a pair of side surfaces  12 . As shown in  FIG. 3 , the case  1  is provided by combining a front case member  15 A which is open at the rear end and a rear case member  15 B which is open at the front end together so that a space  16  for storing articles is defined in these members. To put analytical tools  8  into the space  16 , the front case member  15 A and the rear case member  15 B are separated from each other. 
     A support  17  is provided in the case  1 . The support  17  supports a plurality of analytical tools  8  stacked in the vertical direction and placed on the support  17 . A pushing member  41  is also provided in the case  1 . The pushing member  41  pushes the top of the analytical tools  8  downward by utilizing the resilient force of a spring  40 . The support  17  is so positioned that the lowermost one of the plurality of analytical tools  8  faces the take-out opening  19 . Thus, the analytical tools  8  are taken out of the case  1  through the take-out opening  19  one by one from the lowermost one. For instance, as indicated by phantom lines in  FIG. 1 , the analytical tools  8  are taken out of the case  1  utilizing a pair of arms  70  of the analytical apparatus A. Each of the arms  70  has a hook-shaped end. The take-out opening  19  has a shape which allows the insertion of the end of each arm  70  into the case  1 . Each analytical tool  8  is formed with a cutout. When the arms  70  are inserted into the case  1  through the take-out opening  19 , the arms  70  engage the cutout. Thus, the analytical tool  8  is taken out of the case  1  through the take-out opening  19  while being held by the arms  70 . The lower portion within the case  1  is utilized for accommodating a desiccant  89 . The analytical tool  8  may be provided with a reagent for causing reaction of a sample. The desiccant  89  prevents the quality of the reagent from deteriorating due to moisture. 
     Of the front surface  11  of the case  1 , the periphery of the take-out opening  19  is formed as a tapered surface  18  against which the sealing portion  21  of the cover  2 , which will be described later, is to be pressed. The tapered surface  18  is inclined to project forward from the front surface  11  in such a manner that the projecting amount increases as proceeding in the downward direction D 1 . For instance, the tapered surface  18  is in the form of a rectangular loop surrounding the entire periphery of the take-out opening  19 . 
     The cover  2  includes a frame  20  made of a synthetic resin and the sealing portion  21  for closing the take-out opening  19 . The frame  20  includes a tubular portion  22  slidably fitted around the main portion  10  of the case  1 . The sealing portion  21  comprises a block  21 A made of e.g. synthetic rubber or other elastic materials and held by the frame  20 . The sealing portion  21  is arranged to face the front surface  11  of the case  1 . As shown in  FIG. 3 , the block  21 A may be formed with a slit  210  for increasing elastic deformation. 
     The frame  20  is provided with an extension  23  extending forward from the case  1 . As shown in  FIG. 1 , the extension  23  includes projections  23   a.  When the analytical apparatus A is moved toward the front surface  11  of the case  1 , the projections  23   a  are fitted into guide grooves  72  formed at the upper surface of the analytical apparatus A. By this fitting, the analytical apparatus A and the case unit C 1  are properly positioned relative to each other so that the paired arms  70  are properly inserted into a predetermined portion of the take-out opening  19 . The auxiliary portion  14  of the case  1  is formed with guide grooves  14   a  extending in the front-rear direction. The guide grooves  14   a  are to be fitted to positioning guide portions (not shown) formed at the lower portion of the analytical apparatus A and helps the precise positioning of the analytical apparatus A and the case unit C 1 . 
     As shown in  FIGS. 2 and 4 , each of the side surfaces  12  of the case  1  is formed with a guide groove  30 . Each of the side walls  22   a  of the cover  2  is formed with a guide projection  31  to be received in the guide groove  30 . The combination of the guide groove  30  and the guide projection  31  is an example of guiding means of the present invention. 
     As shown in  FIGS. 5A and 5B , each of the guide grooves  30  is provided by forming two projecting ribs  32   a  on the side surface  12  of the case  1 . The front inner wall  30   a  and the rear inner wall  30   b,  which define the guide groove  30 , extend generally in parallel with each other and linearly in the vertical direction D 1 , D 2 . At a lower portion of the front inner wall  30   a,  a projecting wall portion  30   a ′ is provided which projects toward the rear end of the case  1  (toward the rear surface  13  in this embodiment). The rear inner wall  30   b  is formed with a recess  30   b ′ at a longitudinally intermediate portion. The recess  30   b ′ is formed to avoid interference with a bulging portion  31   b,  which will be described later. 
     Each of the guide projections  31  has a thin elongated form extending in the same direction as the guide groove  30 . The upper end  31   a  of the guide projection  31  has a width Wa which is substantially equal to the width of the guide groove  30 . The lower end  31   c  of the guide projection  31  has a width Wc which is smaller than the width of the guide groove  30 . With this arrangement, as shown in  FIG. 5B , the lower end  31   c  can be inserted into a narrow portion at the lower end of the guide groove  30  behind the projecting wall portion  30   a ′. At a longitudinally intermediate portion of the guide projection  31 , a bugling portion  31   b  is provided which bulges toward the rear end of the case  1 . As shown in  FIG. 5A , when the sealing portion  21  is spaced from the take-out opening  19 , the bulging portion  31   b  is held in contact with the rear inner wall  30   b,  and the front surface of the guide projection  31  is held in surface contact with the front inner wall  30   a  substantially throughout the length. In this state, the guide projection  31  is slidable in the vertical direction D 1 , D 2  while maintaining the posture. In this state, the angle of the surface  21   a  of the sealing portion  21  is also maintained constant. As another means for maintaining the posture of the guide projection  31 , two bulging portions which bulge toward the front end of the case  1  may be provided at the upper end  31   a  and the lower end  31   c  of the guide projection  31 . In this instance, the two bulging portions are held in contact with the front inner wall  30   a,  whereas the bulging portion  31   b  is held in contact with the rear inner wall  30   b,  whereby three-point contact is achieved. 
     When the sealing portion  21  is spaced from the take-out opening  19 , the surface  21   a  of the sealing portion  21  is inclined at a predetermined angle α 1  with respect to the flat surface region of the front surface  11  except the tapered surface  18 . The direction of inclination of the surface  21   a  is the same as that of the tapered surface  18 . The angle of inclination α 1  of the surface  21   a  and the angle of inclination α 2  of the tapered surface  18  are set to satisfy the relationship α 1 &gt;α 2 . 
     As shown in  FIG. 5B , when the sealing portion  21  is moved to face the take-out opening  19 , the lower end  31   c  of the guide projection  31  comes into contact with the projecting wall portion  30   a ′ and is displaced toward the rear end of the case  1 . As a result, the sealing portion  21  is displaced toward the front surface  11  to be pressed against the tapered surface  18 . Herein, the contact between the projecting wall portion  30   a ′ and the lower end  31   c  is made at a position lower than the take-out opening  19 . Further, when the lower end  31   c  is displaced toward the rear end of the case  1 , the cover  2  rotates in the direction indicated by the arrow N 1 . Due to this rotation, the surface  21   a  of the sealing portion  21  becomes parallel with the tapered surface  18 . 
     The operation and advantages of the case unit C 1  will be described below. 
     To take an analytical tool  8  out of the case  1 , the cover  2  is moved upward so that the sealing portion  21  is positioned higher than the take-out opening  19 . By this operation, the take-out opening  19  is opened. In this state, the analytical tool  8  is taken out in the manner as described before. 
     To close the take-out opening  19  after the analytical tool  8  is taken out, the cover  2  is moved downward so that the sealing portion  21  is positioned in front of the take-out opening  19 . As described with reference to  FIG. 5A , when the cover  2  moves downward, the guide projections  31  slide within the guide grooves  30  while maintaining the posture, and the surface  21   a  of the sealing portion  21  is kept inclined at a predetermined angle α 1  with respect to the front surface  11 . Therefore, even when the surface  21   a  comes into sliding contact with the front surface  11 , the entirety of the surface  21   a  does not come into contact with the front surface  11 , and only part of the surface  21   a  comes into contact with the front surface  11 . Thus, the resistance generated during the reciprocal movement of the cover  2  reduces. Further, since the surface  21   a  maintains the same posture during the movement, the degree of contact between the surface  21   a  and the front surface  11  does not vary largely. For these reasons, the cover  2  moves smoothly even by the application of a small force, whereby the usability is enhanced. 
     As described with reference to  FIG. 5B , when the cover  2  is moved downward so that the sealing portion  21  faces the take-out opening  19 , the lower end  31   c  of the guide projection  31  is guided toward the rear end of the case  1  by coming into contact with the projecting wall portion  30   a ′ of the guide groove  30 . As a result, the sealing portion  21  is displaced toward the front surface  11  to be pressed against the tapered surface  18 . Thus, the sealing portion  21  properly closes the take-out opening  19  (see also  FIG. 6 ). With this arrangement, since the sealing portion  21  is displaced toward the take-out opening  19  when moved to face the take-out opening  19 , the sealing portion  21  is reliably pressed against the periphery of the take-out opening  19  even when it is slightly worn. Moreover, in this embodiment, the sealing portion  21  is pressed against the tapered surface  18 . Therefore, as compared with a structure which does not include a tapered surface, the sealing portion  21  is strongly pressed against the periphery of the take-out opening  19  even when the amount of displacement  21  is small. Thus, the sealing portion  21  provides reliable hermetic sealing. 
     In this embodiment, as described with reference to  FIG. 5B , in closing the take-out opening  19 , the cover  2  rotates in the direction indicated by the arrow N 1  so that the surface  21   a  of the sealing portion  21  becomes parallel with the tapered surface  18 . The sealing portion  21  is pressed against the tapered surface  18  by utilizing the rotation. With this arrangement, it is not necessary to strongly press the sealing portion  21  against the tapered surface  18  in moving the sealing portion  21  to face the tapered surface  18 . This also enhances the usability. 
     Since the lower end  31   c  of the guide projection  31  engages the projecting wall portion  30   a ′ and is held behind the projecting wall portion  30   a ′, the closed state of the take-out opening  19  is properly maintained. Particularly, in this embodiment, the lower end  31   c  of the guide projection  31  is inserted and held in the narrow portion at the lower end of the guide groove  30 , as shown in  FIG. 5B . With this arrangement, the closed state of the take-out opening  19  is maintained further reliably. 
     Analytical tools  8  need to be maintained in hygienic conditions, and particularly, need to be stored in moisture-proof and dust-proof conditions. As will be understood from the above, the case unit C 1  reliably provides such conditions, and hence, is suitable for storing the analytical tools  8 . Sometimes it may be necessary to carry analytical tools  8  e.g. on a trip along with the analytical apparatus A. The case unit C 1  comprises the case  1  and the cover  2  slidably fitted around the case  1 . The case  1  itself does not need to be made so large. As for the cover  2 , it is only necessary to make the cover  2  to be slidable along the case  1 , so that the thickness of each part can be made small. Thus, the case unit C 1  can be reduced in size and weight, which is suitable for carrying. 
       FIGS. 7A-7C  show another embodiment of the present invention. In these figures, the elements which are identical or similar to those of the foregoing embodiment are designated by the same reference signs as those used for the foregoing embodiment. 
     In the case unit C 2  shown in  FIGS. 7A-7C , a vertically extending guide groove  30 A is provided at the rear surface  13  of the case  1 . A projecting wall portion  39  projecting toward the rear end of the case  1  is provided at a lower portion of the guide groove  30 A. The cover  2  has a rear wall  22   a  formed with at least one guide projection  31 A which is to be received in and move along the guide groove  30 A. As shown in  FIG. 7C , when the sealing portion is moved to face the take-out opening  19 , the guide projection  31 A is guided toward the rear end of the case  1  by the projecting wall portion  39 . As a result, the sealing portion  21  is pressed against the tapered surface  18 . 
     In this embodiment again, due to the combination of the guide groove  30 A and the guide projection  31 A, the sealing portion  21  is pressed against the periphery of the take-out opening  19  in closing the take-out opening  19  and is prevented from strongly engaging the front surface  11  in other situations. Thus, the opening and closing of the take-out opening  19  is performed smoothly and easily, while ensuring hermetic sealing. 
     As will be understood from this embodiment, when the guiding means of the present invention comprises a guide groove and a guide projection, the guide groove and the guide projection can be provided at portions other than the side surface of the case and the side wall of the cover. Moreover, it is only necessary that the case is provided with one of the guide groove and the guide projection, whereas the cover is provided with the other one of the guide groove and the guide projection. Thus, unlike the foregoing embodiments, the cover may be provided with the guide groove, whereas the case may be provided with the guide projection. The guide projection does not necessarily need to be elongate in the longitudinal direction of the guide groove. For instance, the guide projection may be a columnar projection. 
     The present invention is not limited to the foregoing embodiments. The specific structure of each part of the case unit according to the present invention may be varied in design in many ways. 
     The guiding means of the present invention is not limited to the combination of a guide groove and a guide projection. For instance, a cam mechanism of a type which is different from the combination of a groove and a projection may be employed as the guiding means. As for the case, it is only necessary that the case includes a wall (front surface) formed with a take-out opening, and the shape and the size may be varied. The case may store articles other than analytical tools. In the present invention, the concept of the articles which can be stored in the case includes liquid or other substances which do not have a fixed shape. Since the present invention ensures hermetic sealing of the take-out opening of the case, the case unit of the present invention is also suitable for storing liquid or other flowable substances without leakage. The shape and material of the cover are not limited. Although it is preferable to make the sealing portion of the cover using an elastic material, the material is not limited to a specific one.