Abstract:
A medicine packing apparatus in which a packing sheet ( 7 ) can be printed with predetermined information by a printing device ( 5 ). In the apparatus medicine can be fed into the packing sheet ( 7 ) by a medicine feeder ( 2, 3 ), and the packing sheet ( 7 ) can be sealed by a sealing device ( 8 ) to pack the medicine in a single package. The sealing device ( 8 ) is provided with conveyance portion ( 39 ) for conveying the packing sheet ( 7 ). In the middle of a conveyance path from the printing device ( 5 ) to the sealing device ( 8 ), there are provided a moving mechanism ( 12 ) which comes into contact with the packing sheet ( 7 ) and moves so that the tension of the packing sheet ( 7 ) is held at a constant value, and a position detector ( 33 ) which detects a moved position of the moving mechanism ( 12 ). After the packing sheet ( 7 ) is conveyed by the conveyance portion ( 39 ) and the position detector ( 33 ) detects a predetermined moved position, printing by the printing device ( 5 ) is started.

Description:
BACKGROUND OF THE INVENTION 
   1. Technical Field 
   The present invention relates to a medicine packing apparatus. 
   2. Description of Related Art 
   Conventionally, as a medicine packing apparatus, there has been an apparatus which is provided with two printer heads for printing the medicine packing sheet with patient name, medicine name, usage and so on; between which a detection roller rotatable due to contact with the packing sheet and an encoder for detecting a feed quantity of the packing sheet based on the rotation quantity of the detection roller are provided so that the printer heads are operated based on the detection result of the encoder to print the packing sheet (for example, Japanese patent No. 2579010). 
   However, in the medicine packing apparatus, only the feed quantity of the packing sheet is detected. Therefore, there has been a disadvantage that if the packing sheet is slack between the printer heads and a heat-seal portion at the downstream side of the printer heads when starting the print, the dimension between the print position and the heat-seal position can not be held to be a predetermined value, thus preventing printing at a desired position. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a medicine packing apparatus capable of printing the packing sheet accurately at the desired position. 
   The present invention provides a medicine packing apparatus in which a packing sheet is printed with predetermined information by printing means, medicine is fed into the packing sheet in medicine feed means, and the packing sheet is sealed by seal means to pack the medicine by one package, wherein: 
   the seal means is provided with conveyance portion for conveying the packing sheet; 
   in the middle of a conveyance path from the print means to the seal means, there are provided moving means which comes into contact with the packing sheet and moves so that the tension of the packing sheet is held to be a constant value, and 
   position detecting means which detects a moved position of the moving means; 
   whereby after the packing sheet is conveyed by the conveyance portion and the position detecting means detects a predetermined moved position, print by the print means is started. 
   In the above construction, a dimension between a moved position of the moving means, i.e. a contact position with the packing sheet and a print position by the print means can be made a predetermined value, thereby preventing a shift of the sealing position. 
   The moving means may comprise a roller which is rotatable and movable and urging means which urges the packing sheet with a constant force to eliminate any slack in the packing sheet. 
   It is preferable that the roller is a tension roller attached on a descending and ascending table which descends and ascends along a guide rail, the tension roller forcing up the packing sheet, and that the urging means is a spring for urging the descending and ascending table in an upward direction. 
   It is also preferable that the position detecting means detects a descending position of the descending and ascending table. 
   Further, the present invention provides a medicine packing apparatus in which a packing sheet is printed with predetermined information by printing means, medicine is fed into the packing sheet by medicine feed means, and the packing sheet is sealed by seal means to pack the medicine by one package, wherein: 
   the seal means is provided with conveyance portion for conveying the packing sheet; 
   in the middle of a conveyance path from the print means to the seal means, there is provided tension detecting means which detects a tension act on the packing sheet; 
   whereby after the packing sheet is conveyed by the conveyance portion and tension detecting means detects a predetermined tension of the packing sheet, print by the print means is started. 
   In the above construction, the print by the print means can be started in a condition where a constant tension acts on the packing sheet and no slack exists, thereby enabling formation of a seal at a constant position with respect to the print position. 
   According to the present invention, after the detected tension becomes a predetermined value, print by the printing means can be started, allowing the positional relationship between the conveying position and the print position to be accurately held at a constant value, so as to enable printing at the desired position. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a medicine packing apparatus according to an embodiment of the present invention; 
       FIG. 2  is a perspective view showing a print unit and a packing unit of  FIG. 1 ; 
       FIG. 3  is a front view of the print unit of  FIG. 2 ; 
       FIG. 4  is a partly enlarged front view of  FIG. 3 ; 
       FIG. 5  is an enlarged left side view of  FIG. 4 ; 
       FIG. 6  is an enlarged view in the vicinity of a tension roller of  FIG. 5 ; 
       FIG. 7(   a ) is a plan view of the packing unit of  FIG. 1  and  FIG. 7(   b ) is a front view thereof; 
       FIG. 8  is a schematic illustrative explanatory view showing a conveying path of the packing sheet; 
       FIG. 9  is a partial front view of the packing unit; and 
       FIG. 10(   a ) is an enlarged view in the vicinity of a connection portion between a feed heat-seal portion and a vertical heat-seal portion of the embodiment of the present invention and  FIG. 10(   b ) is an enlarged view in the vicinity of a connection portion between a feed heat-seal portion and a vertical heat-seal portion of a conventional heater roller. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Hereinafter, embodiments according to the present invention will be described in accordance with the accompanying drawings. 
     FIG. 1  shows a medicine packing apparatus according to the embodiment of the present invention. The medicine packing apparatus is provided with a tablet feed portion  2  as the medicine feed means of the present invention and a powder feed portion  3  on the upper side of an apparatus body  1  and provided with a print unit (print means)  5  and a packing unit  8  on the lower side thereof. 
   The tablet feed portion  2  is constructed so that when tablets to be packed into one package are previously manually put in each box formed like a lattice, a bottom plate of each box is sequentially opened to feed the tablets to the packing unit  8 . 
   The powder feed portion  3  is constructed so that, when powder is poured through a hopper  3 , the powder is fed in an outer annular groove of a distribution dish (not shown) and the powder to be packed into one package is scraped out by a powder scraping apparatus (not shown) to feed the powder to the packing unit  8 . 
   The print unit  5  is constructed so that, as shown in  FIGS. 2 to 4 , a packing sheet  7  wound on a roll  6  is rewound and printed with patient name, medicine name, usage and so on and then conveyed to the packing unit  8 . The packing sheet  7  is turned to in horizontal direction by a guide portion  9  and then ink of an ink ribbon  11  is thermal transferred to the upper surface of the packing sheet  7  by means of a thermal transfer portion (printer head)  10 . The printed packing sheet  7  passes through a tension roller  12  and is turned upward by means of a first roller  13 . Then, the packing sheet  7  is guided by a guide piece  14  to move upward and then turned obliquely downward by means of a second roller  15  to advance toward the packaging unit  8 . The ink ribbon  11 , as shown in  FIGS. 3 and 4 , is wound on a first roll  16  and continuously rewound on a second roll  17 . Each of the rolls  16 ,  17  is cylindrical and inner cylinders  16   a ,  17   a  are supported on holding plates  19  which are fixed on both ends of four guide shafts  18  disposed around the rolls to constitute an ink cartridge  20 . An auxiliary roller  22  is rotatably attached to the end of an arm portion  21  extending from the lower guide shaft  18 . 
   The ink cartridge  20  is attached on a side plate  23  by fitting the inner cylinders  16   a ,  17   a  of the rolls  16 ,  17  on shaft portions  24   a ,  24   b  protruding from the side plate  23  and then screwing nuts or so on the ends of shaft portions  24   a ,  24   b . Driving a motor (ink ribbon conveying portion) (not shown) to rotate the shaft portion  24   b  allows the ink ribbon  11 , which is wound on the first roll  16 , to be rewound on the second roll  17 . The ink ribbon  11  is positioned between the thermal transfer portion  10  and the guide portion  9  and the slack of the ink ribbon  11  is removed by an urged roller  25 . The urged roller  26  is rotatably attached on the end of an arm member  26  rotatably provided around a support shaft  26   a . The arm member  26  is urged in a clockwise direction in  FIG. 4  by a spring  27 , one end of which is engaged with an attachment piece  43  that is attached on the apparatus body  1 . 
   The tension roller  12  (moving means), as shown in  FIGS. 5 and 6 , is attached on the support portion  29  extending from a descending and ascending table  28 . The descending and ascending table  28  is provided with a cover  30  for forming a path, through which the packing sheet  7  passes, above the tension roller  12 . The descending and ascending table  28  is provided so as to descend and ascend along guide rails  31  uprightly provided at a predetermined distance and the table is urged upward by a spring  32 . A descending position of the descending and ascending table  28  is specified by detecting a magnet  44  built in the descending and ascending table  28  by means of a sensor  33  (position detecting means) disposed aside. In order to make it possible to easily insert the packing sheet  7 , the descending and ascending table  28  is positioned at a lowest position by engaging an engagement recess portion  29   a  with a engagement piece  45  comprising a leaf spring attached on the side plate  23 . 
   The packing unit  8  is constructed so that the packing sheet  7  printed by the print unit  5  is folded into two or previously has been folded into two. The packing sheet  7  is sealed in a longitudinal direction at predetermined intervals by means of a seal portion  34  that is a sealing means of the present invention to form a bag portion. The medicine fed from the tablet feed portion  2  or the powder feed portion  3  is introduced into the formed bag; and the remaining one side of the packing sheet  7  is sealed. 
   The seal portion  34  is attached in an oblique state corresponding to the packing sheet  7  that advances obliquely downward. In the seal portion  34 , as shown in  FIG. 7 , a pair of feed rollers  39  is intermittently driven via a directly driven gear  38   a  and an intermittently driven gear  38   b  by means of a motor  37  provided on the rear surface side of the side plate  23  of the apparatus body  1 . Thus, the packing sheet  7 , sandwiched between the feed rollers  39 , is intermittently conveyed. 
   Referring further to  FIG. 9 , on the upstream side of the feed rollers  39  with respect to the feed direction of the packing sheet  7 , there are disposed a pair of heater rollers  41 ,  42  and a restriction plate  50  for delivering the packing sheet  7  to the heater rollers  41 ,  42  in a V-shaped opened state. Each of the heater rollers  41 ,  42  is provided with a feed heat-seal portion  51  of circular plate and a vertical heat-seal portion  52  of thin rectangular plate on the lower end of which a roller portion  55  having the same diameter as that of the feed heat-seal portion  51  is integrally formed. The feed heat-seal portions  51 ,  51  are driven rotatably via gears  40   a ,  40   b  and so on by the motor  37  described above. In this embodiment, as the motor  37 , a stepping motor is used so that a change of pulse of the applied voltage allows the conveying quantity to be adjusted. Between the heat-seal portions  51 ,  51  of the both heater rollers  41 ,  42 , both side edges of the packing sheet  7  are sealed. The vertical heat-seal portions  52  are rotatably driven by means of a rotation drive mechanism separately from the feed heat-seal portions  51 ,  51  (but, the rotation axes of the feed heat-seal portion  51  and the vertical heat-seal portion  52  coincide with each other). The vertical heat-seal portions  52  are provided with a pair of heat-seal surfaces  52   a  opposite to each other. Since the vertical heat-seal portions  52  of both heater rollers  41 ,  42  are driven separately from the feed heat-seal portions  51 ,  51 , the seal distance along the conveying direction of the packing sheet  7  formed by the heat-seal surfaces  52   a  can be freely set. 
   Referring  FIG. 10(   a ), construction in the vicinity of the upper end of the vertical heat-seal portion  52  will be explained. On the feed heat-seal portion  51  and the vertical heat-seal portion  52 , small grooves  53  extending in a feed direction of the packing sheet  7  are formed at relatively narrow distances. At the heat seal surface  52   a  in the vicinity of the upper end of the vertical heat-seal portion  52  is formed a diameter enlarging portion  52   b  which extends in an arc-like shape outwardly toward the feed heat-seal portion  51 . Further, between the diameter enlarging portion  52   b  and the end surface of the feed heat-seal portion  51  is formed a heat-seal introducing portion  54  of circular plate having a thin thickness. Referring to  FIG. 10(   b ), in this kind of conventional heat rollers  41 ′,  42 ′, the diameter enlarging portion  52   b ′ of the heat seal surface  52   a ′ of the vertical heat-seal portion  52 ′ has come into direct contact with the end surface of the feed heat-seal portion  51 ′. In such construction of  FIG. 10(   b ), a tension force acts on the packing sheet  7  in the vicinity of the contact portion of the feed heat-seal portion  51 ′ and the vertical heat-seal portion  52 ′ becomes non-uniform, which causes the packing sheet  7  to shift with respect to the feed heat-seal portion  51 ′ and the vertical heat-seal portion  52 ′, resulting in wrinkle in the packing sheet  7  after completion of the seal. On the other hand, in the present invention, as the heat-seal introducing portion  54  of circular plate is formed between the diameter enlarging portion  52   b  and the end surface of the feed heat-seal portion  51  is formed as shown in  FIG. 10(   a ), a tension force acts on the packing sheet  7  in the vicinity of the contact portion of the feed heat-seal portion  51  and the vertical heat-seal portion  52  becomes uniform, which allows the packing sheet to be smoothly introduced between the heater rollers  41 ,  42 , thereby preventing the generation of the aforementioned wrinkle. 
   Operation of the aforementioned medicine packing apparatus will be described. 
   Before starting the packing process, slack of the packing sheet  7  may exist between the heater rollers  41 ,  42  of the packing unit  8  and the thermal transfer portion  10  of the print unit  5 . This slack is eliminated by the urged (biased) tension roller  12  moving upward as shown in two-dots chain line in  FIG. 8 . In this case, the distance between the seal portion  34  and the thermal transfer portion  19  varies in accordance with the quantity of eliminated slack. 
   So, the feed roller  39  is driven to rotate first, allowing the packing sheet to be conveyed. Thus, tension acting on the packing sheet  7  is increased, thereby causing the tension roller  12  to descend against the urging force of the spring  32 . When the sensor  33  (see  FIG. 6 ) detects that the tension roller  12  has descended to the descending position, the thermal transfer portion is heated to start printing of the packing sheet  7 . Thus, the packing sheet  7  can be printed as the tension acting on the packing sheet  7  remains constant, thereby allowing the dimension between the seal portion  34  and the thermal transfer portion  10  to be held at a predetermined value. 
   Subsequently, when the packing sheet  7  with predetermined print is conveyed to the packing unit  8 , the heater rollers  41 ,  42  are rotated so that the packing sheet  7 , which is folded into two, is sealed to make bags. Then, medicine is fed from the tablet feed portion  2  or the powder feed portion  3  in accordance with a prescription data and introduced into the packing sheet  7  via the packing hopper  35 . After that, rotation of the heater rollers  41 ,  42  is continued so that the remaining part of the packing sheet  7  is sealed to complete the packing of medicine to be packed into one package. 
   As described above, according to the medicine packing apparatus, when starting the packing process, printing is surely commenced after descending the tension roller  12  and detecting the descended position thereof by means of the sensor  33 . Therefore, tension force acting on the packing sheet  7  becomes constant, allowing the dimension between the seal portion  34  and the thermal transfer portion  10  to be accurately held to a constant value, enabling the data to be correctly printed at the desired position. 
   In the aforementioned embodiments, although the tension roller  12  is constituted so as to descend and ascend and the position thereof is detected so that the position thereof can be detected so that the dimension between the print position and the seal position of the packing sheet  7  can be held to a predetermined value, it is also allowable that, for example, tension detecting means for detecting tension acting on the packing sheet  7  is provided and printing by the thermal transfer portion  10  is commenced after the tension detected by the tension detection means becomes a predetermined value. As the tension detecting means, an arm or the like that comes into contact with the packing sheet  7  and changes its rotation angle in accordance with the difference in the tension of the packing sheet  7  would be given but the construction thereof would not be limited.