Patent Publication Number: US-2005141945-A1

Title: Separable cutting mechanism for printer

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention is related to a separable cutting mechanism for a printer, and especially refers to a simple cutting mechanism structure for a printer, of which a cutting-knife unit and a printing device can be mutually attracted to integrate with each other and can be separated for independent operations; it is applicable to cutting device on a printer.  
      2. Description of the Prior Art  
      Referring to  FIG. 1 , a current large advanced printer  1  is provided on a printing device with an integrated printing head  11  to print out graphics and texts, and with a cutting-knife unit  12  attached to printer  1  to cut the desired graphics and texts on paper.  
      However, the printing head  11  and the cutting-knife unit  12  of the conventional printer  1  are designed integratedly; they must simultaneously move along on a rail during operation. The printing head  11  is designed to carry multiple ribbon cartridges  13  during color printing, its moving speed is not fast, and weight added by the cutting-knife unit  12  will not affect the normal outputting work of the printing head  11  during printing. However, the cutting-knife unit  12  must drag the printing head  11  to move along on the rail during cutting, thus loading increasing will largely affect its moving speed. In particular, if the knife&#39;s vertical movements are sharp and the cutting-knife unit moves smoothly, then the lines cut will be smooth; otherwise, if the knife&#39;s movement are not sharp and the cutting-knife unit moves slowly, the cutting quality will be poor.  
      In view of the above stated defects, the inventor of the present invention developed the present invention based on years of experience and research to increase the speed and precision of cutting.  
     SUMMARY OF THE INVENTION  
      The main objective of the present invention is to provide a simple structure of separable cutting mechanism for a printer, of which a cutting-knife unit and a printing device can be mutually attracted to integrate with each other and can be separated for independent operations during cutting.  
      To achieve the objective, the separable cutting mechanism for a printer of the present invention comprises: a printing device with rollers used for mounting on a rail of the printer to move transversely; a cutting-knife unit with a carrier having rollers thereon to mount the cutting-knife unit on the rail of the printer and to be installed in juxtaposition with a plurality of printing heads; and an electromagnetic connector provided between the printing device and the carrier of the cutting-knife unit, the electromagnetic connector is provided with a magnetizing coil to generate attraction or release action when the printer is operated.  
      Therefore, the cutting-knife unit and the printing device can be controlled to mutually attract with each other or separate for independent operations.  
      The present invention will be apparent after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic perspective view showing connection of a cutting-knife unit with a printing head of a conventional printer;  
       FIG. 2  is a schematic perspective view showing connection of a cutting-knife unit with a plurality of printing heads in a separable cutting mechanism of an embodiment of the present invention for a printer;  
       FIG. 3  is a top view showing the cutting-knife unit and the printing heads of the embodiment of the present invention;  
       FIG. 4  is a perspective view showing the appearance of the embodiment of the present invention with the cutting-knife unit and the printing heads mutually attracted and mounted on a rail;  
       FIG. 5  is a schematic perspective view showing the cutting-knife unit separated from the printing heads while moving on the rail in use of the embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring to  FIGS. 2 and 3  showing a separable cutting mechanism  2  for a printer of an embodiment of the present invention, it is comprised of: 
          a printing device  21  composed of four printing heads  211  having four monochromatic cartridges  22 , and provided on edges thereof with a plurality of rollers  212  to mount the printing device  21  on a rail  23  of the printer to move transversely;     a cutting-knife unit  24  composed of a carrier  241  having a cutting knife thereon; the carrier  241  is provided on one edge thereof with a locking plate  242 , and has a plurality of rollers  243  on one side thereof to mount the cutting-knife unit  24  on the rail  23  of the printer and being installed in juxtaposition with the printing heads  211 ; and     an electromagnetic connector  25  provided between the printing heads  211  and the carrier  241  of the cutting-knife unit  24 ; the electromagnetic connector  25  is composed of a electromagnetic block  251  and a magnetically attractable metallic block  252 . The metallic block  252  is rectangular and has on one edge thereof locking holes to be locked onto the locking plate  242  of the carrier  241  of the cutting-knife unit  24 . The electromagnetic block  251  is locked onto a lateral side of the outermost printing head  211  on the printing device  21 . The electromagnetic block  251  has a case  253  that has locking holes on both end, the case  253  is provided therein with a magnetizing coil  254  and is provided externally thereof with a magnetic conductive surface, so that the electromagnetic block  251  can provide attraction and releasing function on the metallic block  252  during operations.        

      When practicing, as shown in  FIGS. 3-5 , the electromagnetic block  251  provided on the electromagnetic connector  25  is locked on the outermost printing head  211  of the printing device  21 , while the metallic block  252  is locked onto the locking plate  242  on the carrier  241  of the cutting-knife unit  24 . Therefore when printing, the printer can have the magnetizing coil  254  in the magnetic block  251  controlled, so that the metallic block  252  and the magnetic block  251  can mutually attract each other (as shown in  FIG. 4 ). The printing device  21  integrated during printing graphics and texts and the cutting-knife unit  24  in front of it can move jointly along on the rail  23 .  
      When cutting, the printer can demagnetize the magnetizing coil  254  in the electromagnetic block  251  to release the metallic block  252 , so that the cutting-knife unit  24  can be separated from the printing heads  211  to move independently on the rail  23  during cutting (as shown in  FIG. 5 ).  
      Accordingly, the present invention has the following advantages: 
      1. The separable cutting mechanism for a printer of the present invention applies to the principle of magnetism to allow a cutting-knife unit and a plurality of printing heads to be mutually attracted or separated during operations. Thus with the better mobility, it can effectively overcome the cutting defects of need to drag the printing device resided in the conventional printers.     2. In the present invention, the cutting-knife unit and the printing heads can be separated optionally. Thereby when cutting, the cutting-knife unit does not carry extra weight, and can independently move to and fro along on the rail, so to largely increase speed and precision of cutting.    

      According to the above stated, the present invention can achieve its expected objective to provide a separable cutting mechanism for a printer, it is extremely practicable. Having thus described my invention, what I claim as new and desire to be secured by Letters Patent of the United States are: