Abstract:
A cutter device comprising a fixed blade and a movable blade is disclosed, the movable blade being opposed to the fixed blade and adapted to be displaced in such a manner that an engaging position thereof with the fixed blade shifts continuously. The cutter device is constructed so that the movable blade can be attached to and detached from a body of the device. Thus, attachment and detachment of the movable blade can be effected without requiring any troublesome work.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
         [0001]    The present application is based on Japanese Priority Document JP2002-275881 filed on Sep. 20, 2002, the content of which is incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to a cutter device provided in a printer for printing images, such as, e.g., characters, figures, onto a continuous paper. Particularly, the invention is concerned with a cutter device for cutting continuous paper into an appropriate length.  
           [0004]    2. Discussion of the Background  
           [0005]    Heretofore, various cutter devices have been known for cutting continuous paper into an appropriate length. Printers and facsimile devices using such cutter devices are in many cases provided with a cutter section on a downstream side of a printing section in a paper conveying direction.  
           [0006]    A conventional cutter device is shown in FIG. 9. A rotary type cutter device  100  is provided with a fixed blade  101  which is supported in a fixed state and a movable blade  103  which is rotatable about a support shaft  102 . Fixed blade  101  and movable blade  103  each have a plate-like shape and are arranged in a non-parallel state while allowing respective edges  101   a  and  103   a  to mesh partially with each other.  
           [0007]    In the cutter device  100 , a motor (not shown) and support shaft  102  are connected with each other through a gear train (not shown) or the like and a driving force of the motor is transmitted to the support shaft  102  through a gear train or the like, whereby movable blade  101  is rotated. Such drive components including the motor and the gear train are mounted to a frame  104  which supports fixed blade  101  and movable blade  103 . Movable blade  103  is rotated by the motor through the gear train, causing the meshing position of edges  101   a  and  103   a  to move in one direction, thereby cutting continuous paper which has been fed to between fixed blade  101  and movable blade  103 , like scissors.  
           [0008]    However, in cutter device  100  of such a construction, when movable blade  103  having expired its service life is to be replaced with a fresh one, it is required to disassemble the frame  104  and drive components, or else it will be impossible to detach the movable blade  103 . Thus, blade replacing work is troublesome.  
         SUMMARY OF THE INVENTION  
         [0009]    Accordingly, an object of the present invention is to attach or detach a movable blade without requiring any complicated work.  
           [0010]    The object of the present invention is achieved by a novel cutter according to the present invention.  
           [0011]    The novel cutter device of the present invention is provided with a fixed blade which is supported at a predetermined position and a movable blade opposed to the fixed blade, the movable blade being displaced so that its position of engagement with the fixed blade shifts continuously, the movable blade capable of being attached and detached. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:  
         [0013]    [0013]FIG. 1 is a side view in vertical section showing schematically a printer provided with a cutter device according to the present invention;  
         [0014]    [0014]FIG. 2 is a side view in vertical section showing a disassembled state of a drive unit provided in the cutter device;  
         [0015]    [0015]FIG. 3 is a perspective view of the cutter device;  
         [0016]    [0016]FIG. 4 is an exploded perspective view showing a movable blade and a movable blade holding member both provided in the cutter device;  
         [0017]    [0017]FIG. 5 is a plan view of the movable blade holding member as seen from a cutting edge side of the movable blade in the cutter device, the movable blade holding member being in a state of holding the movable blade;  
         [0018]    [0018]FIG. 6 is a plan view of the cutter device as seen from the cutting edge side of the movable blade;  
         [0019]    [0019]FIG. 7 is a side view showing a structure for effecting a cutting operation in the cutter device;  
         [0020]    [0020]FIG. 8 is a perspective view of the cutter device with an upper unit detached; and  
         [0021]    [0021]FIG. 9 is a perspective view of a conventional cutter device. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    An embodiment of the present invention will be described with reference to the accompanying drawings.  
         [0023]    This embodiment shows an application example to a printer which uses a rolled recording paper.  
         [0024]    As shown in FIG. 1, a printer  1  is provided with a body frame  2  and a drive unit  3  which is attached on an upper side of body frame  2 . Drive unit  3  can be detached with respect to body frame  2  and is normally fixed to body frame  2  with screws  4  (see FIG. 7).  
         [0025]    Drive unit  3  includes an upper unit  5  and a lower unit  6  which are combined together in a separable manner. Upper unit  5  and lower unit  6  have an upper unit frame  7  and a lower unit frame  8 , respectively, which are generally in a rectangular shape and which are each open on one side thereof. Both units  5  and  6  are combined together in a state in which the respective openings are opposed to each other as shown in FIG. 2.  
         [0026]    Upper unit  5  and lower unit  6  are positioned relative to each other by fitting a connecting shaft  9  provided in upper unit frame  7  and a positioning slot  10  formed in lower unit frame  8  with each other. Slot  10  is formed on its upper side in FIG. 1.  
         [0027]    Upper unit frame  7  is fitted in and combined with lower unit frame  8 . In this way a transverse position of upper unit  5  relative to lower unit  6  is guided.  
         [0028]    A paper receptacle portion  12  is formed to body frame  2  to receive and hold a rolled continuous paper  11 . In this embodiment, paper receptacle portion  12  has an arcuate bottom  13 , and a thermal rolled paper having a thermosensitive color developing property is set onto the bottom  13 .  
         [0029]    A paper conveying path  17  indicated by a dot and dashed line in FIG. 1 is in communication with paper receptacle portion  12 . Paper conveying path  17  functions to guide continuous paper  11  drawn out from paper receptacle portion  12  up to a discharge section  16  via a printing section  14  and a cutter device  15  successively. In this embodiment it is assumed hereinafter that paper receptacle portion  12  side of paper conveying path  17  is an upstream side and discharge section  16  side thereof is a downstream side. A guide member  18  is provided along paper convey path  17  to guide continuous paper  11  from the upstream side to the downstream side.  
         [0030]    A description will now be given of printing section  14 . Printing section  14  is provided with a roll-shaped platen  19  and a print head  20  which comes into abutment against platen  19  through paper conveying path  17 .  
         [0031]    Platen  19  is held by upper unit  7  so as to be rotatable about an axis thereof. Platen  19  is also held by lower unit frame  8  rotatably in a coupled state of both upper and lower units  5 ,  6 . A shaft holding portion  21  is formed at lower unit frame  8  to rotatably hold a support shaft  22  of platen  19 .  
         [0032]    With upper unit  5  and lower unit  6  connected together, a gear train (not shown) is connected to a support shaft  22 . This gear train is mounted to lower unit frame  8  and is connected to a motor (not shown) attached in lower unit  6 . A driving force is transmitted from the motor to support shaft  22  through the gear train. Platen  19  rotates with the driving force of the motor to convey continuous paper  11  from paper receptacle portion  12  along paper conveying path  17 .  
         [0033]    Print head  20  is held by a flat plate-shaped head holding member  23  which is provided in lower unit frame  8 . Head holding member  23  is pivotable about a pivot shaft  24  provided in lower unit frame  8 . By rotation with pivot shaft  24  as a center, print head  20  is swinged toward and away from platen  19 . Head holding member  23  is urged in a direction to abut platen  19  by a coiled spring  26  which is stretched between head holding member  23  and a hook member  25  to be described later.  
         [0034]    Since in this embodiment there is used a thermosensitive color developing paper as continuous paper  11 , a thermal head having plural heat generating resistors (not shown) is used as print head  20 . Print head  20  is supported by head holding member  23  in a state in which the heat generating resistors are opposed to platen  19 .  
         [0035]    Print head  20  is not limited to the thermal head, but a suitable print head may be selected according to the type of continuous paper  11  used. For example, in the case of using a pressure-sensitive color developing paper as continuous paper  11 , an impact dot head which carries out printing by projecting wires selectively may be used. Further, for example in the case of using plain paper as continuous paper  11 , an ink jet head which ejects ink in dot form may be used.  
         [0036]    Hook member  25  is provided in lower unit  8  and has a hook  27 , hook  27  being engaged disengageably with support shaft  22  which is held by shaft holding portion  21 . hook member  25  is pivotable about pivot shaft  24  and has a generally V shape with pivot shaft  24  as a turning point. Hook  27  is formed at an end of hook member  25  opposite to pivot shaft  24 .  
         [0037]    A flat plate-like portion  28  of hook member  25  extending to an opposite side from pivot shaft  24  is urged in the direction of arrow “a” in FIG. 2 by coiled spring  26  stretched between the portion  28  and head holding member  23 . As a result, with upper and lower units  5 ,  6  coupled together, hook member  25  is urged in a direction (arrow “a” direction in FIG. 2) in which hook  27  is brought into engagement with support shaft  22  of platen  19 .  
         [0038]    The tip of hook  27  is formed at a predetermined angle relative to a coupling/uncoupling direction (vertical direction in FIG. 1) of upper unit  5  and lower unit  6 . With hook  27  thus formed, as upper and lower units  5 ,  6  are coupled with or uncoupled from each other, hook member  25  pivots against the urging force of coiled spring  26  while escaping its interference with support shaft  22 . In this way, with coupling or uncoupling of upper unit  5  and lower unit  6 , it is possible to lock or unlock the coupling of the two without requiring any special operation. The engagement between hook  27  and support shaft  22  can be released also manually by an operator.  
         [0039]    With upper unit  5  and lower unit  6  uncoupled from each other, hook member  25  and head holding member  23  are urged by coiled spring  26  and are positioned in abutment against positioning faces  29  and  30  respectively which are formed in lower unit frame  8 .  
         [0040]    Cutter device  15  will now be described. As shown in FIG. 3, cutter device  15  is provided with a fixed blade  31  and a movable blade  32 , which are each in a generally flat plate shape.  
         [0041]    Fixed blade  31  is mounted to upper unit frame  7  so as to be pivotable about a pivot shaft  33 . Fixed blade  31  has a base portion  34  as a main component and an edge  35  which is extending from base portion  34  positioned on the side opposite to pivot shaft  33 . Fixed blade  31  is further provided with a guide portion  36  projecting from one end side of edge  35  in a direction away from pivot shaft  33 . Edge  35  of fixed blade  31  has a length which covers the overall width of the continuous paper  11 .  
         [0042]    With fixed blade  31  and movable blade  32  engaged with each other, fixed blade  31  is urged in a direction in which edge  35  faces movable blade  32  by a torsion spring  37  stretched between fixed blade  31  and upper unit frame  7 .  
         [0043]    Movable blade  32  has a base portion  39  (see FIG. 4) as a main component and an edge  40  which is extending from base portion  39 . Two holes  41  are formed apart from each other in base portion  39  (see FIG. 4). Edge  40  of movable blade  32  has a length which covers the overall width of the continuous paper  11 .  
         [0044]    As shown in FIG. 4, movable blade  32  is held by a movable blade holding portion  42 . Movable blade holding portion  42  is provided with a movable blade holding member  43  and pivot shafts  44  ( 44 A,  44 B), pivot shafts  44  being formed at both longitudinal ends of movable blade holding member  43  and supported pivotably by lower unit frame  8 . Movable blade holding portion  42  is disposed in parallel with the axis of platen  19  and is supported by lower unit frame  8  so as to be pivotable about pivot shafts  44 . Movable blade holding portion  42  has a semi-cylindrical cutout portion  45  which permits attaching and detaching of movable blade  32 . Cutout portion  45  has a pair of slots  46  in both longitudinal end positions, slots  46  each having a width equal to the thickness of movable blade  32 . Slots  46  are respectively provided with positioning portions  47  for positioning movable blade  32  which is fitted in cutout portion  45 .  
         [0045]    As shown in FIG. 5, cutout portion  45  is formed so as to be inclined in its longitudinal direction relative to the longitudinal direction of movable blade holding member  43 . The location of one of slots  46  is offset relative to that of the other slot  46  in the longitudinal direction of movable blade holding member  43 , whereby movable blade  32  is held in an inclined state from one end thereof supported by the other slot  46  toward the other end supported by the one of slots  46 . In this embodiment cutout portion  45  is formed so as to be slightly inclined in such a manner that movable blade  32  when fitted in movable blade holding member  43  is slightly inclined from an angle parallel to the axial direction of movable blade holding member  43 .  
         [0046]    In cutout portion  45  there are formed semi-circular protuberances  48  in positions corresponding to holes  41  formed in base portion  39  of movable blade  32 . By engagement with holes  41  formed in base portion  39  protuberances  48  function to fix movable blade  32  to movable blade holding member  43 . Here there is realized a structure for engaging movable blade  32  and movable blade holding member  43  with each other.  
         [0047]    Movable blade holding member  43  used in this embodiment is formed of a resin material having elasticity to such an extent as permits attaching and detaching of movable blade  32  with respect to movable blade holding member  43 .  
         [0048]    With upper unit  5  and lower unit  6  coupled together, fixed blade  31  is urged so as to be pushed against movable blade  32  through guide portion  36  by the biasing force of torsion spring  37 . Guide portion  36  is in contact with movable blade  32  at a position outside the width of continuous paper  11 , whereby between edge  35  of fixed blade  31  and edge  40  of movable blade  32  there is formed a V-shaped path  49  for an object to be cut, as shown in FIG. 6. Edge  35  of fixed blade  31  and edge  40  of movable blade  32  are partially in contact with each other for intermeshing. Here there is realized a structure for supporting the movable blade  32 . The position where edge  35  of fixed blade  31  and edge  40  of movable blade  32  engage each other will hereinafter be referred to as the position X. Path  49  for an object to be cut constitutes a part of paper conveying path  17  and continuous paper  11  is introduced into path  49 . At this time, one surface on paper conveying path  17  side of base portion  39  in movable blade  32  also functions to positionally guide continuous paper  11 .  
         [0049]    The following description is now provided about a structure for effecting the cutting operation of cutter device  15 , which operation is illustrated in FIG. 7. A cutter arm  50  is mounted on the pivot shaft  44 B in movable blade holding portion  42  so as to be pivotable about pivot shaft  44 B. An elongated hole  51  which is long in a direction away from pivot shaft  44  is formed in cutter arm  50 . A drive crank  52  is pivotable about pivot shaft  44  mounted on lower unit frame  8 . A cutter motor (not shown), which is provided in lower unit frame  8 , is connected to drive crank  52  through a gear train  54 . The cutter motor causes drive crank  52  to rotate in a direction of arrow “c” in FIG. 7. An eccentric pin  53  is provided on drive crank  52  and is engaged in the elongated hole  51  so as to be slidable with respect to the elongated hole  51  as drive crank  52  rotates.  
         [0050]    Printing section  14  and cutter device  15  can each function in a coupled state of both upper unit  5  and lower unit  6 .  
         [0051]    In addition, printer  1  is provided with a control section for controlling the operation of its components, though not shown.  
         [0052]    In such a construction, when a printing operation is to be performed, the motor with platen  19  connected thereto and print head  20  are actuated by the control section, thereby printing images onto continuous paper  11  while conveying continuous paper  11  along paper conveying path  17 .  
         [0053]    When the printing is over, a cutter motor (not shown) is turned ON by the control section and a driving force thereof is transmitted to drive crank  52  through gear train  54  to rotate drive crank  52 . At this time, since eccentric pin  53  and elongated hole  51  are in engagement with each other, eccentric pin  53  causes cutter arm  50  to pivot while sliding through elongated hole  51  as drive crank  52  rotates. With the pivotal motion of cutter arm  50 , movable blade holding portion  42  rotates about pivot shafts  44 .  
         [0054]    With rotation of movable blade holding portion  42 , the engaging position X between edge  35  of fixed blade  31  and edge  40  of movable blade  32  shifts in the direction indicated with arrow “d” in FIG. 6 along edge  35  of fixed blade  31 . Here there is realized a structure for displacing movable blade  32 . As a result, the path  49  for an object to be cut is narrowed gradually, and edge  35  of fixed blade  31  and edge  40  of movable blade  32  engage each other like scissors.  
         [0055]    As the movable blade holding portion  42  rotates, an urging force for turning fixed edge  35  upward acts on edge  35  which is positioned above movable blade holding portion  42 . However, since fixed edge  35  is urged in a direction opposite to the pivoting direction thereof with a restoring force of the torsion spring  37 , an interpushing force is exerted between edge  35  of fixed blade  31  and edge  40  of movable blade  32 . Consequently, edge  35  of fixed blade  31  and edge  40  of movable blade  32  are engaged with each other like scissors, whereby continuous paper  11  which has been conducted into path  49  can be cut.  
         [0056]    Although in this embodiment movable blade holding portion  42  which holds movable blade  32  is made rotatable about pivot shafts  44  and the continuous paper  11  is cut by rotating pivot shafts  44 , this constitutes no limitation. For example, there may be adopted a construction wherein movable blade  32  which is held so as to cause tilting of its edge  40  relative to edge  35  of fixed blade  31  is allowed to slide horizontally in FIG. 1 to let path  49  become narrower gradually, thereby engaging edge  35  of fixed blade  31  and edge  40  of movable blade  32  with each other like scissors to cut continuous paper  11  which has been conducted into path  49 .  
         [0057]    Although in this embodiment the fixed blade  31  is disposed in parallel with axis of platen  19  and movable blade  32  is disposed inclinedly relative to the platen axis, this constitutes no limitation. For example, in the case of a cutter device having a structure wherein the continuous paper  11  is cut by sliding movable blade  32  in the parallel direction, fixed blade  31  may be inclined and movable blade  32  in parallel with respect to the axis of platen  19 .  
         [0058]    However, according to cutter device  15  of the rotary type wherein movable blade  32  is rotated as in this embodiment, continuous paper  11  can be cut positively with a simple structure without increasing the size of cutter device  15 .  
         [0059]    In cutter device  15  of this embodiment, when movable blade  32  reaches expiration of its service life, movable blade  32  can be replaced in accordance with the following procedure.  
         [0060]    In replacing movable blade  32 , first upper unit  5  is detached. As a result, movable blade  32  assumes an exposed state as in FIG. 8. Now, the operator can detach movable blade  32  by only a simple operation of pulling out movable blade  32  from cutout portion  45  of movable blade holding member  43 . Here there is realized a structure which permits attaching and detaching of movable blade  32 .  
         [0061]    In this connection, since movable blade holding member  43  is formed of an elastic material, movable blade holding member  43  deflects in a direction to disengage holes  41  and protuberances  48  as movable blade  32  is pulled out from cutout portion  45 . Consequently, movable blade  32  can be detached easily without the need of any troublesome work.  
         [0062]    After movable blade  32  is removed, a new one can be attached by performing the above operation in reverse order.  
         [0063]    In this case, as movable blade  32  is inserted into cutout portion  45 , movable blade holding member  43  deflects in a direction to permit engagement between holes  41  and protuberances  48 , whereby movable blade  32  can be attached easily without requiring any troublesome work.  
         [0064]    With continuous paper  11  conducted to above the movable blade  32 , upper unit  5  is again combined with lower unit  6 , and connecting shaft  9  and positioning slot  10  are fitted together to position upper and lower units  5 ,  6 . In this state support shaft  22  is locked with hook member  25 . Now, printing is ready.  
         [0065]    Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise as specifically described herein.