Abstract:
A printer unit for facilitating maintenance such as repair/replacement of a printer paper winding mechanism and reducing a work time required for the maintenance. The printer unit is mounted removably on a device that requires the printer unit. It comprises a journal printer  4  and a pulley  8  that winds paper P printed by the printer. The printer unit also comprises a body  110  to which the printer is fixed and having a paper shed  3  in which the paper is stored, and a turning arm  140  assembled at one end rotatably with the body  110 . The turning arm  140  has thereon the winding pulley  8  and a platen  143  that is bringable to a position opposite to the printer.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a printer unit mountable on a device that requires the printer unit.  
           [0003]    2. Background Art  
           [0004]    A cash register is provided with a journal-paper winding mechanism that saves a journal on which characters are printed by a printer.  
           [0005]    [0005]FIG. 16 shows a conventional journal paper winding mechanism provided on a cash register. Reference numeral  1  denotes a cash register (device),  2  a drawer,  3  a roll of paper shed,  4  a journal printer,  5  a printer fixing stand,  6  a writing stand,  7  a winding motor,  8  a winding pulley, and P a roll of printing paper.  
           [0006]    A part of a roll of (journal) paper P printed by the journal printer  4  is wound by the winding pulley  8  through the writing stand  6  disposed above the journal printer  4 .  
           [0007]    As shown in FIGS. 17 and 18, the winding pulley  8  has a frictional wheel  81  coaxial with the winding pulley  8  with a rubber roller  71  provided on a shaft of the winding motor  7  engaging the outer periphery of the frictional wheel  81 .  
           [0008]    Therefore, when driving the winding motor  7 , the winding pulley  8  winds the roll of paper through the rubber roller  71  and the frictional wheel  81 .  
           [0009]    When a part of the journal paper P fed out from the journal printer  4  is wound on the winding pulley  8  by the motor  7 , the journal paper winding mechanism has the following problems:  
           [0010]    The feeding speed of the journal paper P determined by the journal printer  4  is not synchronized with the rotational speed of the winding pulley  8  determined by the winding motor  7 . If the winding speed determined by the motor  7  is higher than the rotational speed of the pulley  8 , there occurs friction between the winding motor  7  and the pulley  8  to thereby produce abnormal noise and/or abrasion of the rubber roller  71 . As a result, maintenance such as repair/replacement of the winding mechanism must be performed frequently.  
           [0011]    When such maintenance is, however, difficult to perform and time consuming because the winding mechanism is fixed to the cash register in such a manner that it cannot be removed easily.  
           [0012]    It is an object of the present invention to provide a printer unit capable of easily doing in a reduced time maintenance work such as repair and/or replacement of the printer paper winding mechanism.  
         SUMMERY OF THE INVENTION  
         [0013]    In order to achieve the above object, according to one aspect of the present invention, there is provides a printer unit mountable on a device that requires the printer unit and comprising a printer and a pulley that winds paper printed by the printer, the printer unit also comprising:  
           [0014]    a body to which the printer is fixed and having a paper shed in which the paper is stored, and  
           [0015]    a turning arm assembled at one end rotatably with the body, the turning arm having thereon the winding pulley and a platen that is bringable to a position opposite to the printer.  
           [0016]    Therefore, according to this invention, maintenance work such as repair/replacement of the printer paper winding mechanism is easily done and the work time for the maintenance is reduced.  
           [0017]    According to another aspect of the present invention, there is also provided a printer unit attachable to a drawer provided in a cash register, the printer unit comprising a printer and a winding pulley that winds paper printed by the printer, the printer unit also comprising:  
           [0018]    a paper shed for storing the paper to be fed to the printer;  
           [0019]    a hook for fixing the drawer;  
           [0020]    fixing means for fixing the printer; and  
           [0021]    a turning arm having thereon a platen bringable to a position opposite to the printer, and the winding pulley, turning arm being assembled at one end with the printer unit.  
           [0022]    Therefore, according to this invention, maintenance work such as repair/replacement of the printer paper winding mechanism is easily done and the work time for the maintenance is reduced in the cash register. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]    [0023]FIG. 1 is a disassembled perspective view of an example 1 of a paper winding mechanism;  
         [0024]    [0024]FIG. 2 is a side view of the winding mechanism, showing the positional relationship between the motor and other elements;  
         [0025]    [0025]FIG. 3 is a plan view of the winding mechanism;  
         [0026]    [0026]FIG. 4 is a disassembled perspective view of another example 2 of the structure of the paper winding mechanism;  
         [0027]    [0027]FIG. 5 is a schematic perspective view of a printer unit as a first embodiment of the present invention;  
         [0028]    [0028]FIG. 6 is a side view of an essential part of the printer unit of FIG. 5;  
         [0029]    [0029]FIG. 7 is a schematic perspective view of a printer unit as a second embodiment of the present invention attached to a device with a turning arm turned so as to extend vertically;  
         [0030]    [0030]FIG. 8 is a schematic front view of the printer unit of FIG. 7;  
         [0031]    [0031]FIG. 9 is schematic perspective view of the printer unit of FIG. 7 as viewed from another side;  
         [0032]    [0032]FIG. 10 schematically illustrates the printer unit with its turning arm laid over the unit body;  
         [0033]    [0033]FIG. 11 illustrates the rotating direction of a winding pulley assembled in the printer unit and the winding direction of printing paper;  
         [0034]    [0034]FIG. 12 is an enlarged view of the printer unit of FIG. 9 with its turning arm laid over the unit body;  
         [0035]    [0035]FIG. 13 is a schematic perspective view of the printer unit of FIG. 9 with the turning arm upstanding, as viewed from the side of the turning arm;  
         [0036]    [0036]FIG. 14 shows a battery shed provided in the unit body with a cover shown as removed;  
         [0037]    [0037]FIG. 15 is a schematic perspective view of the unit body as viewed from below;  
         [0038]    [0038]FIG. 16 is a perspective view of a conventional journal paper winding mechanism provided in a cash register;  
         [0039]    [0039]FIG. 17 is a side view of the journal paper winding mechanism of FIG. 16; and  
         [0040]    [0040]FIG. 18 is a plan view of the journal paper winding mechanism of FIG. 16. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0041]    Referring to FIGS.  1 - 6 , a first embodiment of the present invention, that is, a journal printer to be provided in a cash register as mentioned above will be described as an example.  
         [0042]    &lt;Example 1 of the Structure of a Paper Winding Mechanism&gt; 
         [0043]    As shown in FIG. 1, a winding pulley  8  has a shaft  8   a  and a larger end  8   c  between which a flange  8   b  is provided. The larger end  8   c  has a ring-like groove  8   d  extending along its outer periphery. The pulley shaft  8   a  also has a reduced end  8   e  at its other end.  
         [0044]    A frictional wheel  81  that functions as a rotation transmission element to the winding pulley  8  has a coaxial hollow cylinder  82  that fits rotatably over the larger shaft end  8   c  of the pulley  8 , as shown in FIGS. 2 and 3. An E-like ring  83  is fitted in the ring-like groove  8   d  on the outer periphery of the larger shaft end  8   c  in order to prevent the frictional wheel  81  from slipping off from the winding pulley  8 .  
         [0045]    Operation of the journal paper winding mechanism, as described above, will be described next. During operation of the journal printer  4  of FIG. 5, the winding motor  7  is also driven. There occurs a difference between the feeding speed of journal paper P by the journal printer  4  and the winding speed of the journal paper P determined by rotation of the winding pulley  8  transmitted through a rubber roller  71  and the frictional wheel  81  from the winding motor  7 .  
         [0046]    More specifically, when the winding speed of the journal paper P is higher than its feeding speed, no slip occurs between the rubber roller  71  and the frictional wheel  81 . When the winding speed of the journal paper P is lower than its feeding speed, a slip occurs between the frictional wheel  81  and the winding pulley  8  such that the hollow cylinder portion  82  of the frictional wheel  81  of FIG. 1 rotates over the larger shaft end  8   c  of the winding pulley  8  while slipping. Thus, the magnitude of abnormal noise to be produced and abrasion of the rubber roller  71  as the problems with the prior art are reduced.  
         [0047]    &lt;Example 2 of the Structure of the Paper Winding Mechanism&gt; 
         [0048]    As shown in FIG. 4, this mechanism includes a frictional sleeve  84  provided between the outer periphery of the larger shaft end  8   c  of the winding pulley  8  and the inner periphery of hollow cylindrical portion  82  of the frictional wheel  81  that fits over the larger shaft end  8   c  of the winding pulley  8  to thereby allow adjustment of a frictional force between the pulley  8  and the frictional wheel  81  in the structure of the example  1  of the paper winding mechanism of FIGS.  1 - 3 .  
         [0049]    &lt;Structure of the Printer Unit&gt; 
         [0050]    As shown in FIGS. 5 and 6, the printer unit  100  comprises a body  110  having a paper shed  3 , a journal printer  4  fixed to the body  110 , a motor case  120  fixed to the body  110  and in which a winding motor  7  is housed, and a turning arm  140  that supports the winding pulley  8  and the frictional wheel  81 .  
         [0051]    The body  110  includes a case  130  over which the turning arm  140  is supported by a pivot  141  at its end  140   a.    
         [0052]    The motor case  120  is attached integrally to one side of the body case  130  and partially and houses the winding motor  7  therein.  
         [0053]    The turning arm  140  includes a writing stand  6  is provided at ends  140   b  of a pair of side plates  142  engageable with the journal printer  4 .  
         [0054]    As described above, the winding pulley  8  and the frictional wheel  81  are assembled with the turning arm  140 . More particularly, the winding pulley  8  has the hollow cylindrical portion  82  of the frictional wheel  81  rotatably received in  144  in a recess provided on one side plate  142  of the turning arm  140 . The winding pulley  8  also has the other shaft end  8   e  rotatably received in a slit  145  provided in the other side plate  142  of the turning arm  140  and also rotatably fitted in a hole (not shown) in the flange  8   b . Thus, when the journal paper P is wound fully as a roll around the winding pulley  8 , the pulley  8  with its roll can be moved upward to thereby remove the flange  8   b  from the pulley and the roll of journal paper can be pulled laterally away out of the pulley.  
         [0055]    The frictional wheel  81  is assembled rotatably at the end of the pulley shaft  8   a . The detailed structures of the pulley  8  and the frictional wheel  81  of the paper winding mechanism are similar to those of the example 1 or 2.  
         [0056]    The journal paper of the roll P is printed by the journal printer  4  on the printer fixing stand  5 , wound by the pulley  8  provided on the turning arm  140  through the writing stand  6  on the turning arm  140 , and then taken out as a roll.  
         [0057]    As described above, in the printer unit, the body  110  has the paper shed  3  and the journal printer  4  fixed thereto. The body  10  also has the turning arm  140  with which the winding pulley  8  and the frictional wheel  81  are assembled. The motor case  120  in which the winding motor  7  is housed is provided integrally to the printer unit  100 .  
         [0058]    Therefore, maintenance work is achieved satisfactorily as follows: When maintenance such as repair/replacement of the winding mechanism, for example, due to abrasion of the rubber roller  71  is performed, such maintenance can be easily achieved in a short time by turning the turning arm  140  upward. Since the platen  143  is attached integrally to the turning arm  140 , a roll of journal paper P can be easily set by turning the turning arm  140  upward. In addition, when the printer mechanism malfunctions defective, the printer unit  100  can be removed as a unit from the cash register to thereby set immediately a new printer unit  100  instead. The printer unit  100  can be attached removably as a unit to the cash register at one-touch operation.  
         [0059]    A second embodiment of the printer unit  100  according to the present invention will be described next with reference to FIGS.  7 - 15 . Also, in the second embodiment, the same reference numeral is used to denote the same element as that in the first embodiment and further description thereof will be omitted. A pair of hooks  131  is provided at a lower right end of a case  130  of a unit body  110  and respectively engaged disengageably in a pair of holes  231  formed in a top of a drawer  2  of the cash register  1 . A hook  132  is provided on each of both sides of the case  130  at its lower edge and engaged disengageably in a corresponding hole  232  formed in the top of the drawer  2 .  
         [0060]    In assembly, first, the pair of hooks  131  is inserted into and engaged with the holes  231 , and each hook  132  is then inserted into and engaged with the hole  232  on the respective one of the sides of the case  130 . Thus, the unit body  110  is assembled with the drawer  2 . Conversely, by disengaging and pulling the pair of hooks  131  from the pair of holes  231 , and then the hookes  132  from the respective holes  232 , the unit body  110  is removed from the drawer  2 .  
         [0061]    The unit body  110  has an electrical connection  150  connectable/removable to/from a control board  250  (FIG. 7) disposed on the drawer  2  of the cash register  1 . As shown in FIG. 7, a connector  152  for a film board  151  extending from the journal printer  4  at an end of the case  130  is connected to a relay board  153  fixed to an end of the case  130 . A film board  155  is connected to the relay board  153  through a connector  154 . A connector  156  for the film board  155  is connected to the control board  250 . A connector  158  for wiring  157  extending from below the case  130  is connected to the control board  250 .  
         [0062]    By such electrical connection  150 , power supply and drive control to the control board  250  of the cash register, the journal printer  4  and the winding motor  7  is ensured. In addition, a battery (not shown) received in a battery shed  310  supplies power to the control board  250  for backup of a memory. Electric parts such as capacitor  159  are provided on the relay board  153 .  
         [0063]    As shown in FIGS. 8 and 9, a recess  401  is formed on each of the sides of the printer  4  on the case  130  and houses therein an engaging spring  401  and a sensor  403 .  
         [0064]    When the platen  143  is engaged at its opposite shaft ends  143   a  in the recesses  401  and prevented from slipping off from the recesses by the relevant engaging springs  402 , the platen  143  side of the turning arm  140  is secured to the journal printer  4  of the case  130 . At this time, the sensor  403  senses that the platen  143  is set on the journal printer  4  due to the presence of the platen shaft  143   a.    
         [0065]    A gear  404  (FIG. 8) is disposed at one side of the journal printer  4  so as to be rotated by the journal printer. A gear  405  is provided at one end of the platen shaft  143  so as to be engageable with the gear  404  at the side of the journal printer  4 .  
         [0066]    By the meshing of the gears  404  and  405 , paper of a roll P set in the paper shed  3  of the case  130  is fed by rotation of the platen  143  on the journal printer  4  and then wound by the winding pulley  8 , as shown in FIG. 11.  
         [0067]    As shown in FIGS. 10 and 13, the back of the writing stand  6  provided on the turning arm  140  has a handle  410  that is capable of being held by fingers of the user to turn the turning arm  140  upward from the case  130  (unit body  110 ). Conversely, the upward turned arm  140  can be turned so as to overlie on the case  130  by operating the handle  410 .  
         [0068]    As shown in FIG. 14, the battery shed  310  with an openable cover is provided in the body case  130  on the opposite side of the paper shed  3  from the journal printer  4 .  
         [0069]    As shown in FIG. 15, a grounding plate  340  is provided on the bottom of the unit body  110  below the journal printer  4  with springs  341  grounded along with the drawer being provided on the grounding plate  340  so as to cause static charges on the journal printer  4  to escape to the drawer for preventing malfunction of the printer. Pieces of electric wires  157  are provided for feeding electric power from the battery to the memory for backup purposes and from a power supply (not shown) to the motor  7  for driving purposes.  
         [0070]    While in the embodiment the E-like ring is used to prevent the frictional wheel from slipping off from the end of the shaft of the winding pulley  8 , the present invention is not limited to this particular case. For example, a plastic snap fit may be used instead.  
         [0071]    Even in the mechanism for transmitting rotation from the winding motor to the winding pulley, a gear chain may be used instead of the frictional wheel and rubber roller. The specified details of the structure of the printer unit may be appropriately changeable, of course.