Abstract:
An improved guillotine cutter for a printer is disclosed. The guillotine cutter includes a guillotine blade having a cutting motion that helps to urge the cut media from the exit chute of the frame. This reduces the likelihood of the cut media becoming pulled into the frame of the cutter, requiring that the user fish the cut media out. The guillotine cutter further provides a frame having integrated bearing surfaces for supporting many of the movable components of the cutter. This minimizes the complexity of the assembly of the cutter, reducing the number of parts (by elimination of separate bearings and other such additional components) and time required to assemble the cutter.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    Not applicable. 
       STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    This invention generally relates to printers. In particular, this invention relates to a guillotine cutter for a printer. 
         [0004]    Many printers print onto continuous rolls of media. As the media extends through the printer, the media typically is pulled off of a roll, fed past a print head, and fed through an exit chute on the printer. As the media is continuous as it is pulled from the roll, it occasionally needs to be cut to separate the printed portion from the rest of the roll. To sever the media from the roll, a cutter may be placed near the exit chute and actuated to cut the media. 
         [0005]    In one type of cutter, a guillotine cutter, the media is fed through an opening between two blades. When the guillotine cutter is actuated to cut the media, one of the blades is moved past the other blade in a direction that is generally perpendicular to the travel path of the media. The blade actuation severs any media in the opening between the blades. 
         [0006]    The media cut by the cutter is often an adhesive-backed media that is placed on a liner. Adhesive-backed media is commonly used in the printing of labels, barcodes, and the like which are attached to an object after printing. Unfortunately, cutting adhesive-backed media is particularly irksome, as the adhesive of the media tends to builds up on the blades over time. 
         [0007]    This adhesive build-up on the blades degrades the quality of the cut over the life of the blades. In cases of extreme build-up, the blades may not completely cut the media when actuated. 
         [0008]    The adhesive build-up on the blades may also cause the cut media to stick to the cutting edge. In a guillotine-style cutter, this sticking may result in the media not properly feeding from the exit chute, as the portion of the media severed by the cutting edge may continue to travel with the cutting edge even after the media is cut. Correcting this problem may require user intervention to retrieve any media that has not exited the cutter. 
         [0009]    Further, although straightforward in function, cutters typically include complex assemblies with numerous parts. These assemblies may include internal frames, external frames, mounting features, bushings, spacers, and additional fasteners to mount parts. Having a complicated assembly adds cost to the cutter, increases the production time of the cutter, and adds complexity to the cutter. 
         [0010]    Hence, a need exists for an improved cutter that reduces adhesive build-up on the blades over the life of the cutter, improves the ejection of the cut media, and minimizes the complexity of the cutter assembly. 
       SUMMARY OF THE INVENTION 
       [0011]    A guillotine cutter is disclosed for selectively cutting media passing therethrough. The guillotine cutter includes a frame enclosure, a fixed blade, and a guillotine blade. The frame enclosure has a media path extending from an entrance passage to an exit chute. The fixed blade is attached to the frame enclosure. The guillotine blade is movable within the frame enclosure between a first position and a second position. In the first position, the guillotine blade defines a first angle with the media path. In the second position, the guillotine blade has slid past the fixed blade to cut the media and the guillotine blade is angularly offset from the first position and defines a second angle with the respect to the media path. A cutting edge of the guillotine blade pivots towards the exit chute to push the media through the exit chute. 
         [0012]    In one form, the frame enclosure may have a plurality of integrated bearing surfaces formed thereon. The guillotine cutter may further include an actuator mechanism linked to the guillotine blade that actuates the guillotine blade between the first position and the second position. At least a portion of the actuator mechanism may contact the integrated bearing surfaces of the frame enclosure. The actuator mechanism may be operably connected to a motor in the frame enclosure that drives the actuator mechanism. The actuator mechanism may include a crank assembly including a pair of joined rotatable discs linked to the guillotine blade. The crank assembly may further include a pair of links that link the pair of rotatable discs to the guillotine blade. Each of the pair of links may be connected to one the pair of rotatable discs at a location not along an axis of rotation of the pair of rotatable discs. 
         [0013]    In another form, the fixed blade may include a drafted angle for collecting an adhesive from the media. 
         [0014]    In yet another form, the fixed blade has a coating applied thereto to reduce a coefficient of friction of the fixed blade. 
         [0015]    In still another form, the frame enclosure may include a cleaning slot providing access to the fixed blade such that any adhesive buildup can be cleaned from the fixed blade. 
         [0016]    In yet another form, when the guillotine blade is in the second position, the exit chute deflects the media downward, forcing the media to separate from the guillotine blade. 
         [0017]    Other aspects of a guillotine cutter for selectively cutting media are also disclosed. A guillotine cutter includes a frame enclosure, a fixed blade, a guillotine blade, and an actuator mechanism. The frame enclosure has a media path extending from an entrance passage to an exit chute. The frame enclosure also provides a plurality of integrated bearing surfaces. The fixed blade is attached to the frame enclosure. The guillotine blade is movable within the frame enclosure between a first position defining a first angle with the media path and a second position in which the guillotine blade has slid past the fixed blade to cut the media. The actuator mechanism is linked to the guillotine blade and actuates the guillotine blade between the first position and the second position. At least a portion of the actuator mechanism contacts the integrated bearing surfaces of the frame enclosure. 
         [0018]    In one form, in the second position, the guillotine blade may be angularly offset from the first position to form a second angle with the media path. Further, in the second position, a cutting edge of the guillotine blade may angle towards the exit chute to push the media through the exit chute. In the second position, the exit chute may deflect the media downward, forcing the media to separate from the guillotine blade. 
         [0019]    In another form, the guillotine cutter may be modular. 
         [0020]    In yet another form, the actuator mechanism may be operably linked to a motor in the frame enclosure that drives the actuator mechanism. 
         [0021]    In still yet another form, the fixed blade may include a drafted angle for collecting an adhesive from the media. The fixed blade may have a coating applied thereto to reduce a coefficient of friction of the fixed blade. 
         [0022]    In one form, the frame enclosure may include a first frame part and a second frame part. In this form, the integrated bearing surfaces include a first bearing surface from the first frame part and a second bearing surface from the second frame part. 
         [0023]    In yet another form, the actuator mechanism may include a crank assembly including a pair of joined rotatable discs linked to the guillotine blade. The crank assembly may also include a pair of links that link the pair of rotatable discs to the guillotine blade. Each of the pair of links may be connected to one the pair of rotatable discs at a location not along an axis of rotation of the pair of rotatable discs. 
         [0024]    Thus, an improved guillotine cutter is provided. This guillotine cutter includes a guillotine blade having a cutting motion that helps to urge the cut media from the exit chute of the cutter. This reduces the likelihood of the cut media being pulled into the frame of the cutter, requiring that the user fish the cut media out. Further, the guillotine cutter provides a frame having integrated bearing surfaces for supporting many of the movable components of the cutter. This minimizes the complexity of the assembly of the cutter, reducing the number of parts (e.g., by elimination of separate bushings and other such additional components) and the time required to assemble the cutter. This ultimately reduces the cost of producing the cutter. 
         [0025]    These and still other advantages of the invention will be apparent from the detailed description and drawings. What follows is merely a description of a preferred embodiment of the present invention. To assess the full scope of the invention the claims should be looked to as the preferred embodiment is not intended to be the only embodiment within the scope of the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is an environmental view of a guillotine cutter inserted in a carriage for a printer; 
           [0027]      FIG. 2  is a rear-side perspective view of the guillotine cutter; 
           [0028]      FIG. 3  is a front-side perspective view of the guillotine cutter; 
           [0029]      FIG. 4  is a rear-side perspective partial cross-sectional view of the guillotine cutter; 
           [0030]      FIG. 5  is a cross-sectional side view of the guillotine cutter taken along line  5 - 5  of  FIG. 4  in which a guillotine blade is in a lower position; 
           [0031]      FIG. 6  is a cross-sectional side view similar to  FIG. 5 , but in which the guillotine blade is at an intermediate position in which the guillotine blade is cutting the media; 
           [0032]      FIG. 7  is a cross-sectional side view similar to  FIG. 5 , but in which the blade has been moved to the upper position in which the media has been fully cut; and 
           [0033]      FIG. 8  is a detailed cross-sectional view taken along line  8 - 8  of  FIG. 7  in which the build-up of adhesive on the blades is illustrated. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0034]    Referring first to  FIG. 1 , a carriage  10  for insertion in a printer is illustrated. The carriage  10  has a horizontal base wall  12  with two side walls  14  vertically extending therefrom to form a U-shaped cradle. The two side walls  14  have surfaces facing one another that include features formed thereon (e.g., slots or the like) to allow the carriage  10  to support a roll  16  having media  18  wrapped thereabout, a print head assembly  20 , and a guillotine cutter  22 . Most of the components supported by the carriage  10  are designed to be removed for periodic maintenance and/or for replacement after they are consumed. For example, the guillotine cutter  22  is a modular component that is removeably inserted into the carriage  10 . 
         [0035]    In general operation, the printer works as follows. Using various rollers and guides, the media  18  is fed from the roll  16  and past a print head (not shown) in the print head assembly  20 . The print head prints text, an image, a barcode, or the like onto the media  18  as the media  18  passes the print head. In the form shown, this printing is done via thermal transfer of ink onto the media  18 . However, in other forms, this printing could be done using other printing methods including ink jet printing, laser printing, dot matrix printing, and the like to produce the image on the media  18 . Once the media  18  has been printed on, the media  18  is fed through the guillotine cutter  22 . The guillotine cutter  22  cuts the media  18 , as will be described in further detail below, to sever the portion of the media  18  that has been printed on from the rest of the media  18 . 
         [0036]    Referring now to  FIGS. 2 and 3 , the guillotine cutter  22  is shown removed from the carriage  10  of the printer. The guillotine cutter  22  includes a frame  24  having a front frame part  26  and a back frame part  28  enclosing the internal components of the guillotine cutter  22 . The front frame part  26  and the rear frame part  28  are secured together by a set of screws  29 . On the back frame part  28 , an entrance slot  30  and a cleaning slot  31  are formed. On the front frame part  26 , an exit chute  32  is formed. As best shown in  FIG. 5 , a media path extends from the entrance slot  30  to the exit chute  32 . The cleaning slot  31  provides access to the blades for periodic cleaning and provides an opening to remove mis-fed media. 
         [0037]    The guillotine cutter  22  includes laterally outwardly biased support pins for mounting the guillotine cutter  22  in recesses in the side walls  12  of the carriage  10 . These support pins include a set of upper support pins  34  having a pinchable protrusion  36  and a set of lower support pins  38 . Springs or the like bias the sets of support pins  34  and  38  outward. During the installation of the guillotine cutter  22  in the carriage  10 , these support pins  34  and  38  are pressed inward and then snap back outward into recesses in the side walls  14  of the carriage  10  to secure the guillotine cutter  22  in the carriage  10 . 
         [0038]    The sets of support pins  34  and  38  are inserted between the front frame part  26  and the back frame part  28  during the assembly of the guillotine cutter  22 . The sets of support pins  34  and  38  directly bear on the integrated bearing surfaces  39  of the frame  24 . Thus, no complex installation of a support pin sub-assembly into the frame  24  is necessary during the manufacture of the guillotine cutter  22 . 
         [0039]    Referring now to  FIG. 4 , a fixed blade  40  and a guillotine blade  42  are enclosed with the frame  24 . The guillotine blade  42  is linked to an actuator mechanism  46  that urges the guillotine blade  42  past the fixed blade  40  to cut the media  18  as will be described in further detail below with reference to  FIGS. 5-7 . 
         [0040]    The fixed blade  40  is attached to the back frame part  28  by a set of screws  44 . The fixed blade  40  has a drafted angle  45  as is best seen in  FIG. 8 , which forms a stationary cutting edge. 
         [0041]    The guillotine blade  42  has a movable cutting edge  48  extending between a left end  50  and a right end  52  of the guillotine blade  42 . The movable cutting edge  48  is angled as the guillotine blade  42  extends from the left end  50  to the right end  52  such that, as the guillotine blade  42  moves past the fixed blade  40 , a cutting action between the movable cutting edge  48  and the stationary cutting edge is provided that is similar to the cutting action of a pair of scissors. 
         [0042]    Near the bottom of each of the lateral sides of the guillotine blade  42 , a set of shaft-like projections  54  are formed on either end of the guillotine blade  42  for connection to the actuator mechanism  46 . These projections  54  also extend through a set of slots  55  formed along the lateral connection seam between the front frame part  26  and the back frame part  28 . 
         [0043]    In the form shown, the actuator mechanism  46  includes a number of components. The actuator mechanism  46  includes an electric motor  56  which is secured between the front frame part  26  and the back frame part  28  and is viewable from the outside of the guillotine cutter  22  for connection to a power supply (not shown) and a control board  58  (shown in  FIG. 1  as being mounted to an outwardly-facing surface of one of the two side walls  14  of the carriage  10 ). The electric motor  56  has an output shaft  59  which drives a gear train  60  comprising multiple shafts with gears thereon. One of the gears of the gear train  60  drives the rotation of a crank assembly  62 . 
         [0044]    The crank assembly  62  transfers the motion of the gear train  60  to the guillotine blade  42 . The crank assembly  62  includes a shaft  64  having discs  66  attached to each end. A gear  69  attached to the shaft  64  intermeshes with at least one of the gears on the gear train  60  to cause the rotation of the shaft  64  about the axis of rotation  67 . In the form shown, the discs  66  on each end of the shaft  64  have a tab  68  formed thereon that turns with the motion of the disc  66  and shaft  64 . During the rotation of the discs  66  and shaft  64 , this tab  68  may travel past a sensor  70  to determine the position of the crank assembly  62 . 
         [0045]    A set of links  72  in the crank assembly  62  connect each of the discs  66  to the guillotine blade  42 . One of the ends of each of the links  72  is attached to one of the projections  54  on the guillotine blade  42 . The other end of each of the links  72  is attached to a projection  74  formed on each of the discs  66 . The projection  74  is located at a distance from the axis of rotation  67 . Given the connectivity of the set of links  72  to the discs  66  and the guillotine blade  42 , the set of links  72  act as a crank which translates the rotation of the shaft  64  and discs  66  to a linear driving motion of the guillotine blade  42  at the projection  54 . 
         [0046]    A number of integrated bearing surfaces support the crank assembly  62 . Notably, in the form shown, the set of links  72  are held on the projections  54  of the guillotine blade  42  and the projections  74  of the discs  66  by a set of integrated bearing surfaces  76  on lateral walls the frame  24 . During assembly of the guillotine cutter  22 , the set of links  72  are slid over the projections  54  and  74  and inserted between the front frame part  26  and the back frame part  28 , which are then joined together. When the front frame part  26  and the back frame part  28  are joined, the crank assembly  62  is enclosed by the frame parts  26  and  28 . The set of integrated bearing surfaces  76  are formed on the lateral walls of the frame parts  26  and  28  prevent the set of links  72  from falling off of the projections  54  and  74 . Further, a set of integrated bearing surfaces  78  support the shaft  64  of the crank assembly  62 . As the shaft  64  rotates, the surface of the shaft  64  and the integrated bearing surfaces  78  engage one another. 
         [0047]    The inclusion of the integrated bearing surfaces  39 ,  76 , and  78  reduce the number of components required in the assembly of the guillotine cutter  22 . The various components of the guillotine cutter  22  are simply assembled and placed into the frame parts  26  and  28 , which are then joined. To improve the performance of the integrated bearing surfaces  39 ,  76  and  78 , the frame parts  26  and  28  are fabricated from a material having a low coefficient of friction. All of the bearing surfaces for the components are surfaces of the front frame parts  26  and/or the back frame part  28 , eliminating the need for separate bushings, lubrication, spacers, and the like, which add cost and complexity to the assembly. 
         [0048]    Referring now to  FIGS. 5-7 , the cutting operation is illustrated. 
         [0049]    In  FIG. 5 , the guillotine blade  42  is in a lower position in which the media  18  can pass though an opening  80  between the fixed blade  40  substantially perpendicular to the media path and the guillotine blade  42 . Typically, when the media  18  is being printed on, the guillotine blade  42  is in this lower position, such that the media  18  can be fed though the opening  80 . 
         [0050]    In  FIG. 6 , the guillotine blade  42  is lifted to a position in which the movable cutting edge  48  of the guillotine blade  42  passes the fixed blade  40  to cut the media  18 . This movement of the guillotine blade  42  occurs when the electric motor  56  drives the operation of the gear train  60 , which drives rotation of the shaft  64  and discs  66 , which drives the upward movement of the set of links  72 , which in turn drives the upward movement of the guillotine blade  42 . 
         [0051]    Referring now to  FIG. 7 , the guillotine blade  42  has been actuated to an upper position in which the guillotine blade  42  has fully severed the portion of the media  18  that has been printed on from the rest of the media  18 . Once the cutting of the media  18  is complete, the electric motor  56  continues to drive the mechanism to the lower position of  FIG. 5  to re-establish the opening  80  for the passage of the media  18 . In the form shown, the motor is driven in one direction through the entire cut cycle. 
         [0052]    Notably in  FIG. 7 , as the guillotine blade  42  approaches the upper position, the guillotine blade  42  tilts or pivots towards the exit chute  32  defining a non-perpendicular angle with the media path. As the guillotine blade  42  tilts or pivots towards the exit chute  32 , the guillotine blade  42  is angularly offset from the orientation of the guillotine blade  42  in the lower position as shown in  FIG. 5 . In the form shown, this can occur as the guillotine blade  42  is pivotally fixed at its bottom end at the connection between the projections  54  and the set of links  72 , while the top end (closest to the movable cutting edge  48 ) is not connected to anything and “floats”. A portion of the frame  24  or some other biasing mechanism may cause this tilting or pivoting as the guillotine blade  42  is raised. 
         [0053]    This tilting or pivoting of the movable cutting edge  48  of the guillotine blade  42  toward the exit chute  32  helps to separate the cut media from the guillotine blade  42  by slightly increasing the contact angle between the media  18  and the movable cutting edge  48  of the guillotine blade  42 . When an adhesive is present in the media  18 , this tilting or pivoting assists in separating the media  18  from the guillotine blade  42  if the some of the adhesive from the media  18  sticks to the movable cutting edge  48  of the guillotine blade  42 . 
         [0054]    Additionally, the exit chute  32  is formed such that the media  18  exiting the exit chute  32  is forced downward, encouraging the separation of the media  18  that has been cut from the guillotine blade  42 . The exit chute  32  has a top lip above the opening that slopes downward as it extends away from the frame  24 . If and when the cut media contacts this top lip, usually in the event that the cut media sticks to the guillotine blade  42 , the cut media is forced downward by the top lip of the exit chute  32 . 
         [0055]    Further, the tilting or pivoting of the guillotine blade  42  assists in pushing or urging the media  18  through the exit chute  32 . This reduces the likelihood of the media  18  becoming stuck in the guillotine cutter  22  or not properly ejecting from the exit chute  32 . 
         [0056]    Referring now to  FIG. 8 , a detailed view shows the build-up of adhesive  82  on the fixed blade  40  and the guillotine blade  42 . The adhesive primarily collects on the vertical face of the fixed blade  40  and the back face of the guillotine blade  42 . The vertical face of the fixed blade  40  is coated with a coating  84  having a low coefficient of friction such that the collected built-up adhesive  82  creeps up the fixed blade  40  away from the cutting edge. As the cutting edge  48  of the guillotine blade  42  swings away from the vertical face of the fixed blade  40 , this provide a space on the fixed blade  40  for the adhesive  82  to build up. Further, as the guillotine blade  42  moves past the fixed blade  40 , the edge of the fixed blade  40  slides along the back face of the guillotine blade  42  pushing the adhesive down the back face and away from the cutting edge  48 . The collected adhesive on the back side of the guillotine blade  42  may be periodically removed by the user through the cleaning slot  31 . 
         [0057]    It should be appreciated that while a guillotine cutter has been described having a guillotine blade that is raised to cut the media, in other forms the guillotine blade could be lowered to cut the media. If the guillotine blade is lowered, then it is contemplated that the cutting edge of the guillotine blade may be likewise tilted or pivoted towards the exit chute to assist in the separation of the cut media from the guillotine blade and to urge the cut media out of the exit chute. 
         [0058]    Many modifications and variations to this preferred embodiment will be apparent to those skilled in the art, which will be within the spirit and scope of the invention. Therefore, the invention should not be limited to the described embodiment. To ascertain the full scope of the invention, the following claims should be referenced.