Patent Publication Number: US-2007095960-A1

Title: Paper shredder cutting tool

Description:
BACKGROUND OF THE INVENTION  
      (a) Field of the Invention  
      The present invention relates to a paper shredder cutting tool that is easily manufactured, effectively avoids paper jam, and reduces legibility of contents of shredded paper pieces.  
      (b) Description of the Prior Art  
      Referring to  FIG. 1 , a conventional paper shredder cutting tool has cutting tools that are constructed to include two cylindrical rotary cutters  10  and  10 ′. Each of the rotary cutters  10  and  10 ′ is mounted on a polygonal shaft  12 , and a plurality of cutting blades  14  is securely mounted on the shafts  12 . A paper guide  16  is configured between each pair of adjacent cutting blades  14 , thus partitioning the cutting blades  14  therebetween, and thereby allowing the cutting blades  14  to be assembled and mounted in an interleaving fashion on the two cylindrical rotary cutters  10  and  10 ′. Moreover, each of the cutting blades  14  is further constructed from a pair of blades, and the protruding cutting blades  18  are configured to circumferences thereof.  
      As shown in  FIG. 1  and  FIG. 2 , a motor  100  of the cutting tool is the main driving component. A decelerator  200  joints the shafts  12  of two sets of rolling blades  10  and  10 ′ with the motor  100 . Two sets of rolling blades  10  and  10 ′ perform reciprocal rolling motions driven by the motor  100  to shred papers passing through into pieces.  
      The aforesaid configuration of the conventional paper shredder cutting tool can indeed shred papers into pieces. However, using the principle of the configuration of the interlaced cutting blades  14  slicing papers into strips, and the protruding cutting blades  18  configured on the circumferences of the cutting blades  14  cutting strips of the papers to pieces, thickness of the papers to be shredded is limited by the height of the protruding cutting blades  18 , and the width of the shredded pieces is considerably wide. In other words, contents of the shredded pieces are more likely to be legible; thus, contents of the documents may be exposed to undesirably fail the purpose of shredding the documents.  
      Furthermore, tips of the cutting blades  14  move in parallel to the paper input direction to worse dragging effects. Paper jam can easily occur resulted from paper pieces piled up during the operation.  
      Taking the aforesaid issues into consideration, the present invention enhances the conventional paper shredder cutting tool by providing a cutting tool that is easily manufactured and convenient, while effectively avoids paper jam and reduces legibility of contents of shredded paper pieces.  
     SUMMARY OF THE INVENTION  
      The primary object of the invention is to provide a paper shredder cutting tool that is easily manufactured, effectively avoids paper jam and reduces legibility of contents of shredded paper pieces. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  shows an elevational schematic view of a conventional paper shredder cutting tool.  
       FIG. 2  shows a top view of a conventional paper shredder cutting tool.  
       FIG. 3  shows a structural top view of the cutting tool according to the present invention.  
       FIG. 4  shows a shape of a of a shredded paper piece according to the present invention.  
       FIG. 5  shows another shape of a shredded paper piece according to the present invention.  
       FIG. 6  shows a structural sectional view of one tip of a blade in a blade module according to the invention.  
       FIG. 7  shows a structural sectional view of two tips of a blade in a blade module according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      According to  FIG. 3 , the invention consists of two sets of parallel cylindrical rolling blades  3  and  3 ′ side-by-side, a motor  1  as main driving component and a decelerator  2  jointing the rolling blades  3  and  3 ′ with the motor  1 . Driven by the motor  1 , two sets of rolling blades  3  and  3 ′ perform reciprocal turning motions to shred the papers passing through into asymmetrical small pieces  6  as shown in  FIG. 4  and  FIG. 5 .  
      The invention is characterized in that, several blade modules  4  are configured correspondingly in two sets of rolling blades  3  and  3 ′. Referring to  FIG. 6  and  FIG. 7 , each blade module  4  comprises a straight first plate-shaped blade  41  and an adjacent curved second plate-shaped blade  42  to form asymmetrical blade tips with one straight side and one curved side thereof.  
      During operation, the second plate-shaped blade can be formed as a slightly curved shape or a more obvious curved shape through stamping process with characteristics of easy manufacturing. Furthermore, a polygonal axle center aperture is respectively configured on the first and second plate-shaped blades of each blade module. Wherein, the number of sides of the axle center aperture is at least two more than that of the axle shaft going through. A plurality of acute protruding cutting blades is respectively configured at the circumferences of the first and second plate-shaped blades. Each protruding cutting blade is configured in unequal azimuths. When the first and second plate-shaped blades are assembled adjacently, a fixed angle is formed by corresponding protruding cutting blades of the first and second plate-shaped blades.  
      According to  FIG. 3 , a paper guiding piece  5  for partitioning is configured between the blade modules  4 , so as to arrange the blade modules  4  on two sets of rolling blades  3  and  3 ′ in an interlacing fashion. When two sets of rolling blades  3  and  3 ′ turn reciprocally, the blade modules  4  thereof cut the shredded papers off by jointing tips of the blades.  
      Resultingly, the papers can be cut into asymmetrical small pieces  6  as in  FIG. 4  and  FIG. 5 . The small piece  6  in  FIG. 4  is cut by the second plate-shaped blade with the slightly curved shape, and the small piece  6  in  FIG. 5  is cut by the second plate-shaped blade with the obvious curved shape. The legibility of the contents are reduced because tips of the small pieces are in acute angles and the small pieces are in a shape with asymmetrical sides.  
      During operation, the curved side of the blade tip is non-parallel to paper input direction to provide dragging effects and thus preventing paper jam. Moreover, the blade tips of the rolling blades can be configured in a spiral fashion to avoid all blades and tips of the blades falling on the same axle to fuirther disperse stress during paper shredding motion, thereby improving durability of the blades and minimizing possible damages of the paper shredder.