Abstract:
The present invention discloses an improved structure of a cutter knife, comprising of a front casing, a rear casing, a front support pad, a rear support pad, a slider, a sliding bracket, a knife cartridge, a tail blade, a press button, a blade stopper, a stop block button and stopper button. Besides providing a convenient way of replacing the blades, the knife cartridge is capable of accommodating a plurality of spare blades, and the tail blade enhances the practicality and application of the cutter knife.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an improved structure of a cutter knife, more particularly to a cutter knife with a more secure and safer grip, comprising a front casing, a rear casing, a front support pad, a rear support pad, a slider, a knife cartridge, a tail blade, a press button, a blade stopper, a stop block button and stopper button. Besides providing a convenient way of replacing the blades, the knife cartridge is capable of accommodating a plurality of spare blades, and the tail blade enhances the practicality and application of the cutter knife. 
     2. Description of the Prior Art 
     In general, a traditional cutter knife has a sliding bracket and a single-sided wavy groove in the slider. Usually, these components are worn out, and reduce the latch function. Thus, the blade cannot be effectively fixed into the desired position, and also has the risk of causing slashes to users when the cutter knife is in use. Furthermore, the spare blades of the cutter knife are generally placed somewhere other than the knife itself. When the user needs to replace blades, it may take some find to locate the spare blades. In view of the existing shortcomings of the prior-art cutter knife, the inventor of the present invention with many years in the related field performing a series of researches and developments to enhance the cutter knife structure, and finally succeeds to invent the present invention. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide an improved structure of a cutter knife, such that the cutter knife makes use of the smooth engagement of its slider and wavy stopping groove of the front casing to improve the latching effect and safety of the blade; furthermore, the knife cartridge of the present invention can accommodate a plurality of spare blades and integrate with the cutter knife as a whole to improve the convenience of replacing blades, and the tail knife also improves the practicality and application of the cutter knife. 
     To make it easier for our examiner to understand the objective of the invention, its structure, innovative features, and performance, we use a preferred embodiment together with the attached drawings for the detailed description of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, in which: 
     FIG. 1 is an illustrative diagram of the assembled structure of the present invention. 
     FIG.  2  and FIG. 3 are illustrative diagrams of the disassembled parts of the structure of the present invention. 
     FIG. 4 is an illustrative diagram of the slider structure of the present invention. 
     FIG. 5 to FIG. 8 are illustrative diagrams of the press button structure of the present invention. 
     FIG. 9 is the illustrative diagrams of the stop block button structure of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to FIG. 1 to FIG.  3 . The improved structure of a cutter knife of the present invention comprises a front casing  1 , a rear casing  2 , a front support pad  3 , a rear support pad  4 , a slider  5 , a knife cartridge  6 , a tail blade  66 , a press button  62 , a blade stopper  7 , a stop block button  8  and a stopper button  9 ; wherein: 
     the front casing  1 , being an integral casing plate, having a circular groove  11  at the rear end of the front casing  1 , and a plurality of latch holes  12  being disposed at the rear section of the front casing  1 , and the front casing  1  at its middle section having a positioning hole  13 , and the positioning hole  13  on both of its inner sides having a rectangular groove  14 , furthermore the front casing  1  at the middle section of its inner side having a fixed screw hole  15 , and the front casing  1  at the upper edge of the rear section of its inner side having a circular protruded axle  16 , and the protruded axle  16  at its edge having a positioning sliding rod  17  with a diameter smaller than the protruded axle  16 , and the front casing at the rear end of its inner side having a fixed screw hole  18  in the shape of a stairway-like rod, and the front casing  1  at the inner side of the upper edge of its front section having a wavy stop block groove  19 ; 
     the rear casing  2 , being an integral casing plate, having a circular hole  21  at the rear end of the rear casing  2 , and the rear casing  2  at its rear section having a plurality of latch holes  22 , and the rear casing  2  at its middle section having a circular hole  23 , and furthermore, the rear casing  2  at the inner side of the top at its rear end having a positioning axle  25  protruded inward, and the rear casing  2  at the bottom of its middle section having a fixed groove  27 ; 
     the front support pad  3 , being integrally made of a soft plastic material, having a circular hole  31  disposed at its rear, and the front support pad  3  at the periphery of its inner side having a plurality of latch protrusion  32 ; 
     the rear support pad  4 , being integrally made of a soft plastic material, having a plurality of latch protrusion  41  on the periphery of its inner side; the slider  5 , being integrally bent and formed from a metal plate, having a circular hole  51  each on both sides of its upper edge, and furthermore, the slider  5  at its lower edge having an aslant bent plate  52 , and the tail end of the aslant bent plate  52  at its inner side having a latch protrusion  55 ; 
     the knife cartridge, being an integral cartridge substantially in the shape of a hollow trapezoid casing, and an axle hole  61  at the top of its tail section; 
     the press button  62 , being an integral hollow cylinder, having a circular hole groove  63  at the middle section of one of its sides, and the press button  62  at a side of its bottom having a sheath ring  64  protruded from a side of its bottom and a protruded pillar  65  on the other side; 
     the tail blade  66 , having an axle hole  67  at the middle section of one of its end, and the tail blade  66  at its bottom having a vertical surface  68 , and the tail blade  66  at the upper edge of its rear section having a through latch hole  69 ; 
     the blade stopper  7  (please refer to FIG.  4 ˜FIG.  8 ), further comprising a blade base  71 , a push button  72 , and a blade replacing switch  73 , wherein: 
     the push button  72  having a long rectangular embedding plate  722 , and the embedding plate  722  at its middle section having an arc embedding member  723 , and the push button  72  at its lower section having a vertical support pillar  724 , and the push button  72  at a side of its middle section having a circular protruded pillar  725 , and the embedding plate  722  at its front edge of the lower section having a protruded pillar  726 , and the push button  72  having a soft lining  727  wrapped around its upper section; 
     the blade replacing switch  73 , having a semicircular latch protrusion  731  at a side of the bottom edge of its front end, and the blade switching switch  73  at the middle section of its upper edge having a circular protruded pillar  732 , and the blade switching button  73  at a side of its tail end having a support axle  733 ; the blade base  71 , having a T-shaped embedding plate at the upper edge of its front end, and an embedding plate  712  at the lower edge, and the embedding plate  712  at its rear section having a latch groove  715 , and the blade base  71  at its middle section having a rectangular hole groove  713 , and furthermore the blade base  71  at the upper edge of the tail having a semicircular support axle hole  714 ; 
     the blade stopper  7  latching the support axle  733  at a side of its tail end into the semicircular support axle hole  714  at the upper edge of its end, and the push button  72  using the protruded pillar  726  and the protruded pillar  732  at the middle section of the blade replacing switch  73  sleeving and latching a spring  74 , and the vertical pillar  724  at the lower section of the push button  72  sleeving and latching a spring  75 , and then latching into the rectangular hole groove  713  of the blade base  71 , and the blade  76  using the semicircular latch groove  77  of the blade  76  to embed and fix the latch protrusion  731  on a side of the bottom of the front end of the blade replacing switch to constitute a blade stopper  7 ; 
     the stop block button  8  (please refer to FIG.  9 ), being in the shape of a circular rod, having a rectangular support sliding member  81  each on both sides of one of its ends, and the stop block button  8  at the top of one of its ends having a rectangular latch protrusion  82 , and furthermore, the stop block button at the middle section of its end having circular protruded pillar  83 ; 
     the present invention makes use of a protruded pillar  725  on a side of the push button  72  of the blade stopper  7  to latch and fix the inner side of the upper edge of the front section of the front casing  1  into the wavy stop block groove  19 , and the stopper button  9  being latched to the upper edge of the front section of the front casing  1 , and the stop block button  8  being disposed into the positioning hole  13  at the inner side of the middle section of the front casing  1 , and the circular protruded pillar  83  at an end sleeving a spring  84 , and the blade cartridge  6  latching the axle hole  61  to the protruded axle  16  at the upper edge of the rear section of the inner side of the front casing  1 , and the press button  62  using a sheath ring  64  to sleeve the positioning sliding rod  17  at the rear section of the inner side of the front casing  1 , and in the circular hole groove  11  at the rear end of the front casing  1  and the tail blade  66  using axle hole  67  at the end section to couple with the external stairway-like rod around the fixed screw hole  18  at the rear end of the inner side of the front casing  1 ; furthermore, the slider  5  using two screws  54  to couple the circular hole  51  on both sides of the upper edge and secure the screw hole  24  at the upper edge of the inner side of the rear section of the rear casing  2  with screws, such that the rear casing  2  and the front casing  1  being mutually aligned and engaged, and two screws  26  individually being secured into the circular holes  21 ,  23  on the rear casing  2  respectively, and the rear support pad  4  using the plurality of latch protrusions  41  on the periphery of the inner side to embed and attach the plurality of latch holes  22  at the rear section of the rear casing  2 , and the front support pad  3  using the plurality of latch protrusions  32  to embed and attach the plurality of latch holes  12  at the rear section of the front casing  1  to constitute an integral structure of the cutter knife. 
     The protruded pillar  725  of the push button  72  of the present invention is latched and positioned in the wavy stop block groove  19  of the front casing  1 . When a user presses the push button  72  down, the protruded pillar  725  separates the wavy stop block groove  19  and push the push button  72  outward such that the push button  72  together with the blade base  71 , the blade replacing switch  73 , and the blade  76  slide outward until the blade slides to an appropriate position, and then the push button  76  is released. The push button  72  uses the elasticity of the spring  74 ,  75  to bound back upward, and the protruded pillar  725  also latches into the wavy stop block groove  19  in order to accomplish the safe and reliable movement of the blade. If the user wants to draw the blade  76  back, then pushing the blade similarly in the reverse direction allows the user to draw back the blade  76 . 
     If the user wants to replace the blade, the user just needs to press the blade replacing switch  73  down while the blade  76  of the cutter knife is being pushed outward, and the blade replacing switch  73  uses the support axle  733  as the axle center of the swing, so that the latch protrusion  731  at the front end of the blade replacing switch  73  is separated from and the latch groove  77  of the blade  76  to remove the blade  76 . The new blade is then placed into the cutter knife, and then the blade switching switch is released, so that the blade replacing switch bases on the elasticity of the spring  74 ,  75  to drive the latch protrusion  731  to latch the blade  76  into the latch groove  77  to complete the blade replacement. 
     From the disclosure of the structure of the present invention as described above, the present invention definitely has the following merits: 
     1. The top of the push button  72  of the present invention is wrapped with a soft lining  727  to improve the comfort and stability of pushing the button by fingers. 
     2. The blade cartridge  6  of the present invention can accommodate a plurality of spare blades to provide a convenient way of replacing the blades for the users. 
     3. The tail blade  66  of the present invention improves the flexible effect on application, and the slider  5  having a latch surface  53  at the tail of its aslant bent plate  52  can prop against and latch the vertical surface at the bottom of the tail blade  66 , so that the tail blade  66  can be used in a stable condition, and the tail blade  66  further has a latch hole. When the tail blade  66  is folded back into the cutter knife, the latch protrusion  55  of the slider  5  is used to latch and secure the tail blade  66  to improve the safety. 
     4. The stop block push button  8  and the latch protrusion  82  at the top of the stop block push button  8  of the present invention prop against latch into the latch groove  715  at the lower edge of the blade base  71 , so that the blade stopper  7  keeps the blade  76  inside the cutter knife. Unless the user presses the stop block push button  8  inward to detach the latch protrusion  82  from the latch groove  715  of the blade base  71 , and release the limitation and fixing of the slider  5 , so that the slider can move the blade  76  back and forth, which provides a safe and protective structure. 
     In summation of the above description, the present invention herein enhances the performance than the conventional structure and further complies with the patent application requirements and is submitted to the Patent and Trademark Office for review and granting of the commensurate patent rights. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.