Abstract:
The guillotine cutter of the present invention has a fixed blade and a movable blade that moves back and forth along a straight line while contacting against the fixed blade, and the movable blade and the fixed blade cooperate to cut a tape-shaped object for cutting in a widthwise direction. In addition, a surface of the fixed blade at a side that contacts the movable blade and a surface of the movable blade at a side that contacts the fixed blade are provided with a recess portion which is a concave portion that is wider than the object for cutting.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a guillotine cutter and tape affixing apparatus and more particularly to a guillotine cutter capable of cutting adhesive tape smoothly and continuously without any adhesive agent from the adhesive tape adhering to the blade tip thereof, and to a tape affixing apparatus having the guillotine cutter. 
     2. Description of the Related Art 
     A planographic printing plate bundle in which a predetermined number of planographic printing plates are accumulated in the thickness direction is usually packed with a light shielding/moisture-proof paper, and a method of then affixing joints of the light shielding/moisture-proof paper with adhesive tape in order to prevent light or air from entering from outside has been widely used. 
     In recent years, the affixing of the tape has often been carried out with an automatic tape affixing apparatus. Conventionally, the automatic tape affixing apparatus comprises a cutter for cutting the adhesive tape to a predetermined length and an affixing roller which rolls along the surface of the planographic printing plate bundle for affixing the adhesive tape cut with the cutter. As the aforementioned cutter, a guillotine cutter comprising a movable blade and a fixed blade has been widely used. 
     However, in the conventional guillotine cutter, adhesive agent from the adhesive tape adheres to a blade face of the movable blade because the blade face of the movable blade makes contact with a cut edge of the adhesive tape after the adhesive tape is cut. Then, when the movable blade and fixed blade make contact with each other, this adhesive agent is pushed around such that a gap is generated between the movable blade and the fixed blade, which gives rise to cutting failure whereby the adhesive tape is not cut properly. 
     Further, feeding failure occurs whereby remaining adhesive tape after cutting adheres to adhesive agent left on the blade faces of the movable blade and fixed blade so that the adhesive tape is not fed properly when a feeding operation is carried out. 
     Recently, an adhesive agent sticking prevention apparatus in which an adhesive agent sticking prevention agent such as silicone oil is applied to the cutter blade of an adhesive tape affixing machine has been proposed in a prior document (Japanese Patent Application Laid-Open (JP-A) No. 2004-000937). 
     However, the adhesive agent sticking prevention apparatus described in the prior document is intended for a rotary cutter having a rotary blade which cuts by rotating from a non-adhesive face of the adhesive tape toward its adhesive face, and the adhesive tape is prevented from adhering to the blade by contacting a contact member, which is structured so that it exudes sticking prevention agent onto an outer face thereof, against the rotary blade, which rotates in a specified direction, to thus coat the blade with the sticking prevention agent. 
     However, the adhering agent sticking prevention apparatus is considered to be unsuitable for a guillotine cutter because the movable blade of guillotine cutter moves linearly with respect to the fixed blade without rotating, unlike the rotary cutter. 
     Therefore, in order to effectively prevent reduction of cutting performance due to adhesion and deposit of the adhesive agent of the adhesive tape on the blade face and clogging of the adhesive tape in the guillotine cutter, so as to enable adhesive tape to be cut smoothly even after it is cut plural times, a new adhesive agent sticking prevention mechanism, different from the adhesive agent sticking prevention apparatus described in the above document, is required. 
     SUMMARY OF THE INVENTION 
     The present invention has been achieved in view of the above-described situation and an object of the invention is to provide a guillotine cutter including a fixed blade and a movable blade making linear reciprocating motion while contacting the fixed blade, in which the movable blade cooperates with the fixed blade to cut a tape-like object for cutting in a widthwise direction, and in which a surface of the fixed blade that contacts the movable blade and a surface of the movable blade that contacts the fixed blade are each provided with a recess portion which is a concave portion wider than the object for cutting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram showing the structure of a tape affixing apparatus according to a first embodiment. 
         FIG. 2  is an enlarged view showing the structure of a guillotine cutter provided on the tape affixing apparatus shown in  FIG. 1 . 
         FIGS. 3A ,  3 B are perspective views showing the detail of an upper blade and a lower blade of the guillotine cutter shown in  FIG. 2 . 
         FIG. 4A  is a plan view of the upper blade of the guillotine cutter shown in  FIG. 2  as seen from a side at which it makes contact with the lower blade. 
         FIG. 4B  is a sectional view showing a cross-section of the upper blade along a plane perpendicular to the plan view in  FIG. 4A . 
         FIG. 4C  is an enlarged view showing the structure of the blade tip of the upper blade and the surrounding structure. 
         FIG. 5A  is a plan view of the lower blade of the guillotine cutter shown in  FIG. 2  as seen from a side at which it makes contact with the upper blade. 
         FIG. 5B  is a sectional view showing a cross-section of the lower blade along a plane D-D′ perpendicular to the plan view in  FIG. 5A . 
         FIG. 5C  is an enlarged view showing the structure of the blade tip of the lower blade and the surrounding structure. 
         FIG. 6  is a perspective view showing another example of the upper blade and lower blade of the guillotine cutter shown in  FIG. 2 . 
         FIG. 7  is a sectional view of the upper blade and lower blade shown in  FIG. 6 . 
         FIG. 8A  is a perspective view showing yet another example of a lower blade of the guillotine cutter shown in  FIG. 2  and  FIG. 8B  is a sectional view thereof. 
         FIGS. 9A ,  9 B are diagrams showing the operation process of the tape affixing apparatus shown in  FIG. 1 . 
         FIGS. 10A ,  10 B are diagrams showing the operation process of the tape affixing apparatus shown in  FIG. 1 . 
         FIGS. 11A-11C  are diagrams showing the operation process of cutting the adhesive tape with the guillotine cutter of the tape affixing apparatus shown in  FIG. 1 . 
         FIGS. 12A-12C  are diagrams showing the operation process of cutting the adhesive tape with the guillotine cutter of the tape affixing apparatus shown in  FIG. 1 . 
         FIG. 13  is an explanatory diagram of the effect exerted by the tape affixing apparatus shown in  FIG. 1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     1. First Embodiment 
     An embodiment of the tape affixing apparatus of the present invention will be described below. 
     As shown in  FIG. 1 , the tape affixing apparatus  100  of the first embodiment comprises a guillotine cutter  2  for cutting an adhesive tape  202  to a predetermined length; an adhesive tape feeding portion  4  for winding off adhesive tape  202  from an adhesive tape roll  204  and feeding it to the guillotine cutter  2 ; a table  6  which is located below the guillotine cutter  2  and on which a planographic printing plate bundle  200 , including a predetermined quantity of planographic printing plates laminated in a thickness direction and packaged with a light shielding/moisture proof paper, is placed; a draw roller  8  which is raised and lowered by a cylinder  10  in order to receive an end of the adhesive tape  202 , the other end of which is pasted to the top face of the planographic printing plate bundle  200 , and pull it downward along a side face of the planographic printing plate bundle  200 ; and a wrap-around roller  12  which advances/retracts with respect to the table  6  and wraps the adhesive tape  202 , pulled downward by the draw roller  8 , on a side face and the bottom face of the planographic printing plate bundle  200  thus affixing it. The adhesive tape feeding portion  4  corresponds to an adhesive tape feeding device in the tape affixing apparatus of the invention, and the draw roller  8 , the cylinder  10 , the wrap-around roller  12  and the cylinder  14  correspond to a tape affixing device in the tape affixing apparatus and at the same time, corresponds to a tape wrap-around portion in the tape affixing apparatus. 
     As shown in  FIGS. 1 ,  2 , the guillotine cutter  2  comprises a lower blade  20 , an upper blade  21  and a pedestal  22  which holds the upper blade  21  and moves it along the lower blade  20  in both directions as indicated by Arrow ‘a’ in  FIG. 2 . The lower blade  20  and upper blade  21  correspond to a fixed blade and movable blade in the guillotine cutter of the invention. 
     The lower blade  20  is mounted on a holder  24  that is swingable around a shaft  27  which is perpendicular to the direction of movement of the upper blade  21 . Because the holder  24  is urged to rotate in the opposite direction to the direction indicated by Arrow ‘b’ in  FIG. 2  by a spring  26 , the lower blade  20  is always kept in contact with a blade tip  21 A regardless of the position of the upper blade  21 . 
     The pedestal portion  22  is provided with a suction portion  25  for holding by suction the adhesive tape  202  cut by the upper blade  21  and lower blade  20 , and is moved up and down or reciprocated along the directions indicated by Arrows ‘a’ and ‘a′’ by a cylinder  23 . The range of the reciprocation of the pedestal portion  22  is set so that the adhesive tape  202  is cut by the upper blade  21  and the lower blade  20  and when it is lowered to the bottom, the suction portion  25  makes contact with the planographic printing plate bundle  200  placed on the table  6 . 
     As the pedestal portion  22  is lowered, the upper blade  21  is also lowered together therewith and the lower blade  20  is pressed by the blade tip  21 A of the upper blade  21  so that it swings in the direction of Arrow ‘b’ against an urging force from the spring  26 . On the other hand, if the pedestal portion  22  is raised, the upper blade  21  is also raised together therewith so that the lower blade  20  is swung in an opposite direction to the Arrow ‘b’ around the shaft  27  by the urging force from the spring  26 . As a consequence, the upper blade  21  moves up and down with at least the blade tip  21 A making contact with the lower blade  20 . 
     The suction portion  25  corresponds to a tape end affixing portion in the tape affixing apparatus of the invention. 
     As shown in  FIG. 1 , the adhesive tape feeding portion  4  comprises a feeding roller  42  located below a conveying path P of the adhesive tape  202 , a feeding roller  44  located upstream of the feeding roller  42  with respect to the feeding direction ‘c’ of the adhesive tape  202 , a nipping roller  46  located opposite to the feeding roller  42  across the conveying path P for nipping the adhesive tape  202  together with the feeding roller  42 , a drive motor  48  located above the nipping roller  46  for driving the feeding roller  42  and the feeding roller  44  and a pair of holding rollers  50  located between the feeding roller  42  and the nipping roller  46  and the lower blade  20  of the guillotine cutter  2  for holding the adhesive tape  202  fed by the feeding roller  42  and the nipping roller  46  so that it is fed properly into the guillotine cutter  2 . 
     A drive pulley  48 A is fixed to the rotation shaft of the drive motor  48  and likewise, a driven pulley  42 A and a driven pulley  44 A are fixed to the feeding roller  42  and the feeding roller  44  respectively. A belt  49  is wound around the drive pulley  48 A, the driven pulley  42 A and the driven pulley  44 A, so that a rotation of the drive motor  48  is transmitted to the feeding roller  42  and the feeding roller  44  via the belt  49 . The diameters of the drive pulley  42 A and the driven pulley  44 A are controlled so that the peripheral velocities of the feeding roller  42  and the feeding roller  44  are equal. In the meantime, a tachometer  48 B for detecting a number of revolutions is provided on the drive motor  48 . 
     The nipping roller  46  is mounted on a front end of an arm  47  that is swingable around a shaft  45 . The arm  47  is urged by a spring  43  in a direction in which it rotates toward the feeding roller  42  and, therefore, the nipping roller  46  is urged against the feeding roller  42 . 
     The surfaces of the feeding roller  42 , the feeding roller  44  and the holding roller  50  are coated with a fluorine resin such as polytetrafluoroethylene resin, vinylidene fluoride ethylene copolymer resin, and tetrafluoroethylene hexafluoro propylene copolymer resin or a low friction material such as ultrahigh molecular weight polyethylene, to prevent the adhesive agent from adhering thereto, because the respective surfaces make contact with the adhesive face of the adhesive tape  202 . 
     Hereinafter, the upper blade  21  and the lower blade  20  of the guillotine cutter  2  will be described. 
     As shown in  FIGS. 2 ,  3 A,  3 B, and  4 A- 4 C, the upper blade  21  is formed into a plate having as a whole a rectangular planar shape and the surface on the side making contact with the lower blade  20  is finished with a planar configuration while the blade tip  21 A is formed on the bottom of this surface. An inclined plane, which is inclined toward the blade tip  21 A, or a swagging face  21 E is formed on the opposite side of the blade tip  21 A. Therefore, the bottom end portion of the upper blade  21  is formed in the form of a wedge whose thickness decreases as it goes toward the blade tip  21 A. 
     A recess portion  21 B, which is a substantially rectangular concave portion wider than the adhesive tape  202  to be cut is provided from the vicinity of the blade tip  21 A of the upper blade  21  toward the base of the blade tip  21 A. The bottom end portion of the recess portion  21 B shown in  FIGS. 3 and 4  is chamfered into a semi-circular shape for reasons related to production. The recess portion  21 B communicates with a concave portion  21 D formed in the root portion of the upper blade  21 . 
     As shown in  FIGS. 4B ,  4 C, the depth of the recess portion  21 B is 0.5 mm or more. Further, the width of a blade tip front end face  21 C that contributes to the cutting of the adhesive tape  202  from the blade tip  21 A to the recess portion  21 B is in a range of 1.2 to 1.5 mm. 
     If the depth of the recess portion  21 B in the upper blade  21  is 0.5 mm or more, the cross section of the cut adhesive tape  202  makes contact with no portion of the upper blade  21  other than the blade tip front end face  21 C and therefore, no adhesive agent adheres to any portion other than the blade tip front end face  21 C. If the width of the blade tip front end face  21 C is in the range of 1.2 to 1.5 mm, even if adhesive agent from the adhesive tape  202  adheres to the blade tip front end face  21 C, no large amount of adhesive agent adheres to the upper blade  21  and the lower blade  20  because the amount of adhering agent that adheres to the blade tip front end face  21 C is extremely small. 
     As shown in  FIGS. 2 ,  3 A,  3 B,  5 A- 5 C, the lower blade  20  is plate-shaped and an opening portion  20 E, which is open to an ascent direction ‘a′’ in which the upper blade  21  ascends, is provided, and a shallow V-shaped blade tip  20 A is formed at a lower surface of the opening portion  20 E. A surface at the side making contact with the upper blade  21  is finished in the form of plane and at the opposite side of the blade tip  20 A an inclined face which is inclined toward the blade tip  20 A, or a swagging face  20 D, is formed. With the lower blade  20  mounted at the holder  24 , a substantially rectangular opening portion  20 F through which the adhesive tape passes is formed by the opening portion  20 E and the holder  24  as shown in  FIGS. 2 and 12 . 
     A recess portion  20 B, which is a substantially rectangular concave portion wider than the adhesive tape  202 , is provided adjacent to the blade tip  20 A at a face of the lower blade  20  which makes contact with the upper blade  21 . 
     As shown in  FIGS. 5B ,  5 C, the depth of the recess portion  20 B is 0.5 mm or more, as with the upper blade  21 . The width of the blade tip front end face  20 C, that contributes to cutting of the adhesive tape  202 , from the blade tip  20 A to the recess portion  20 B is in a range of 1.2 to 1.5 mm. 
     If the depth of the recess portion  20 B in the lower blade  20  is 0.5 mm or more, the section of the cut adhesive tape  202  contacts no portion of the lower blade  20  other than the blade tip front end face  20 C and, therefore, no adhesive agent adheres to any portion other than the blade tip front end face  20 C. If the width of the blade tip front end face  20 C is in the range of 1.2 to 1.5 mm, even if adhesive agent of the adhesive tape  202  adheres to the blade tip front end face  20 C, as in the case of the upper blade  21 , a large amount of adhesive agent does not adhere to the upper blade  21  or the lower blade  20  because the amount of adhering agent is extremely small. 
     In the upper blade  21  and the lower blade  20 , as shown in  FIGS. 6 ,  7 , the recess portion  21 B and the recess portion  20 B may be formed in the form of a slope so that the depth increases as it leaves the blade tip  21 A or the blade tip  20 A. In this case, the depth of a portion 20 mm apart from the blade tip  21 A or the blade tip  20 A is preferred to be 0.5 mm or more. Further, the width of the blade tip front end face  21 C and the blade tip front end face  20 C is preferred to be 0.5 mm or less. 
     Further, the lower blade  20  is preferably coated with low friction coating from the blade tip  20 A across the swagging face  20 D as indicated with a dotted area in  FIGS. 8A ,  8 B. Examples of the material that can be used as the low friction coating include fluorine resin or ultrahigh molecular weight polyethylene which are mentioned as low friction materials with respect to the feeding roller  42 , the feeding roller  44  and the holding roller  50  in the adhesive tape feeding portion  4 . 
     Hereinafter, the operation of the tape affixing apparatus  100  will be described. 
     As shown in  FIG. 9A , first, the adhesive tape  202  is fed out from an adhesive tape roll  204  to the guillotine cutter  2  along a feeding direction ‘c’ by the adhesive tape feeding portion  4 . 
     When the adhesive tape  202  is fed by a predetermined length, the adhesive tape  202  is cut by the guillotine cutter  2  as shown in  FIG. 9B  and then an end of the cut adhesive tape  202  is pasted to the top face of the planographic printing plate bundle  200 . 
     A process for cutting the adhesive tape  202  with the guillotine cutter  2  will be described with reference to  FIGS. 11 ,  12 . 
     As shown in  FIGS. 11A ,  12 A, the adhesive tape  202 , after being fed from the adhesive tape reel  204 , passes through an opening portion  20 F of the lower blade  20  from a side provided with the swagging face  20 D along a direction of Arrow ‘c’ and arrives below the suction portion  25 . 
     When feeding of the adhesive tape  202  is stopped, the upper blade  21  descends toward the lower blade  20  along the direction of Arrow ‘a’ as shown in  FIGS. 11B ,  12 B and the adhesive tape  202  is cut and the cut adhesive tape  202  is suctioned by the suction portion  25 . Then, as the pedestal portion  22  descends toward the planographic printing plate bundle  200  as shown in  FIGS. 11C ,  12 C, the adhesive tape  202  suctioned by the suction portion  25  is pasted to the planographic printing plate bundle  200 . 
     When an end of the cut adhesive tape  202  is adhered to the top face of the planographic printing plate bundle  200 , the cylinder  10  is extended so that the draw roller  8  rises as shown in  FIG. 10A . After the draw roller  8  sticks to the other end of the adhesive tape  202 , the cylinder  10  is contracted as shown in  FIG. 10B  and then the draw roller  8  is lowered, so that the other end of the adhesive tape  202  is pulled downward along the side face of the planographic printing plate bundle  200 . 
     After the other end of the adhesive tape is pulled downward, the cylinder  14  is extended and the wrap-around roller  12  advances to the table  6 , so that the adhesive tape  202  is wrapped around the top face, the side face and the bottom face of the planographic printing plate bundle  200 . 
     In the tape affixing apparatus  100 , since the upper blade  21 , which is a component part of the guillotine cutter  2 , is provided with the recess portion  21 B, as shown in  FIG. 13 , when the upper blade  21  descends and the adhesive tape  202  is cut, a remaining end face of the cut adhesive tape  202  does not come into contact with the recess portion  21 B and the upper blade  21  descends as far as to its lowest point. Therefore, as regards the upper blade  21 , adhesive agent only adheres to the blade tip front end face  21 C and does not adhere to the greater part of the surface at a side facing the lower blade  20 . 
     Further, because the lower blade  20  is provided with the recess portion  20 B, when the upper blade  21  rises after finishing cutting of the adhesive tape  202 , adhesive agent adhered to the blade tip front end face  21 C does not adhere to the surface of the lower blade  20  at a side facing the upper blade  21 . 
     Thus, because no adhesive agent is deposited on any of the upper blade  21  or the lower blade  20  after the cutting of the adhesive tape  202  is repeated plural times, no gap is generated between the upper blade  21  and the lower blade  20 , thereby causing no cutting failure. Further, it never happens that a portion of the adhesive tape  202  cut improperly is torn away and sticks to the blade tip  20 A of the lower blade  20  causing feeding failure of the adhesive tape  202 . 
     Further, because a portion of the swagging face  20 D of the lower blade  20  near the blade tip  20 A is coated with low friction material, no adhesive agent adheres to the swagging face  20 D even if the front end of a remaining portion of cut adhesive tape  202  makes contact with the swagging face  20 D, and feeding failure of the adhesive tape  202  is thus effectively prevented. 
     As explained above, in the guillotine cutter of the present invention, because the surface of the movable blade at a side that contacts the fixed blade is provided with a recess portion, when the guillotine cutter is used for cutting the adhesive tape, the movable blade makes contact with a cut end of the adhesive tape only via the blade tip front end face that contributes to cutting and extends from the blade tip to the recess portion, so that the amount of adhesive agent from the adhesive tape that adheres to the movable blade is extremely small. 
     Further, because the surface of the fixed blade that contacts the movable blade is also provided with a recess portion, adhesive agent sticking to the movable blade is prevented from being spread over and deposited on the fixed blade. 
     Therefore, generation of cutting failure due to a gap between the movable blade and the fixed blade is effectively prevented and, additionally, occurrence of feeding failure of the adhesive tape due to an improperly cut portion of the adhesive tape being torn away and sticking to the blade tip of the fixed blade is also prevented. 
     A second aspect of the invention relates to the guillotine cutter of the first aspect in which the swagging face of the fixed blade is coated with a low friction resin. 
     In the guillotine cutter, a object to be cut such as adhesive tape is usually fed from the fixed cutter to the movable cutter. Therefore, when the adhesive tape is cut, a cut end of the cut adhesive tape comes into contact with the swagging face of the fixed blade, namely, a face on an opposite side to the blade tip front end face. 
     However, because the swagging face of the fixed blade of the guillotine cutter is coated with a low friction resin, even if the cut end of an adhesive tape remaining after cutting comes into contact with the swagging face of the fixed blade, no adhesive agent sticks to the swagging face. 
     A third aspect of the invention relates to the guillotine cutter of the first and second aspects, in which the recess portions of the fixed blade and the movable blade have a depth of 0.5 mm or more. 
     The adhesion of adhesive agent from the adhesive tape to portions of the guillotine cutter other than the blade tips is effectively prevented by making the recess portions of the fixed blade and the movable blade have a depth of 0.5 mm or more. 
     A fourth aspect of the invention relates to the guillotine cutter of the third aspect in which the width from the blade tip to the recess portion of the blade tip front end faces, which contribute to cutting, of the fixed blade and the movable blade is from 0.5 mm to 1.5 mm. 
     A fifth aspect of the invention relates to the guillotine cutter of the third aspect in which the width from the blade tip to the recess portion of the blade tip front end faces, which contribute to cutting, of the fixed blade and the movable blade is from 1.2 mm to 1.5 mm. 
     In these guillotine cutters, since the width of the blade tip front end faces of both the fixed blade and the movable blade is small, the amount of adhesive agent that adheres thereto when ends of the adhesive tape contact the blade tip front end faces is extremely small. 
     Accordingly, cutting failure and feeding failure of the adhesive tape caused by adhesive agent adhered to the fixed blade and the movable blade is effectively prevented. 
     On the other hand, since the width of the blade tip front end faces is not excessively small, neither the blade tip of the movable blade nor the blade tip of the fixed blade are chipped as a result of the impact when the respective blade tips contact. 
     A sixth aspect of the invention relates to a tape affixing apparatus for affixing adhesive tape to a package, which includes a guillotine cutter of any of the first to fifth aspects, adhesive tape feeding device for feeding adhesive tape toward the guillotine cutter, and tape affixing device for affixing adhesive tape that has been cut at the guillotine cutter to the surface of a package. 
     In the tape affixing apparatus, since there is no occurrence of cutting failure or feeding failure of the adhesive tape at the guillotine cutter, neither is there any occurrence of affixing failure at the tape affixing device caused by cutting failure or feeding failure. 
     A seventh aspect of the invention relates to a tape affixing apparatus of the sixth aspect, in which the tape affixing device is provided with a tape end affixing portion that presses an end of the adhesive tape cut at the guillotine cutter against the package and affixes it thereto, and a tape wrap-around portion that wraps the adhesive tape, of which one end has been affixed to the package by the tape end affixing portion, around the surface of the package. 
     According to the tape affixing apparatus, it is extremely easy to affix adhesive tape to the surface of a package.