Abstract:
An improved structure art design knife that provides for stabler and safer manual grasping, the arrangement of which includes a front cover, a back cover, a hatch, a flat spring, and a blade holder mechanism. In addition to convenient blade replacement, the art design knife of the present invention contains a plurality of spare blades, thereby enhancing the utility of such structures and, furthermore, increasing practical value from a production standpoint.

Description:
BACKGROUND OF THE INVENTION 
     1) Field of the Invention 
     The invention herein relates to utility cutters and knives, specifically an improved structure art design knife that provides for stabler and safer manual grasping, the arrangement of which includes a front cover, a back cover, a hatch, a flat spring, and a blade holder mechanism. In addition to convenient blade replacement, the art design knife of the present invention contains a plurality of spare blades, thereby enhancing functionality and, furthermore, increasing practical value from a production standpoint. 
     2) Description of the Prior Art 
     In a conventional art design knife, frictional wear between the tensile pawl and the wave-profiled rack of the blade extension/retraction, mechanism often reduces overall structural rigidity such that blades cannot be consistently fixed into position, resulting in a greater risk of user injury. Moreover, the spare blades of a conventional art knife are typically situated external to the body of the knife. As such, considerable time is wasted searching for extra blades whenever a blade has to be replaced. Given the existent drawbacks of the conventional product and the need to overcome them, the applicant of the invention herein innovated an original solution and conducted extensive research based on design and other experience gained while engaged in the related industrial fields that culminated in the successful development of the improved structure art design knife of the invention herein. 
     SUMMARY OF THE INVENTION 
     The objective of the invention herein is to provide an improved structure art design knife in which the blade holder mechanism and the rack of the front cover and the back cover are of a balanced and stable arrangement to achieve blade positioning more effectively and safely and, furthermore, the present invention accommodates the internal storage of a plurality of spare blades, thereby integrating an extra blade supply within the body of the art design knife itself to further enhance blade replacement convenience and efficiency. 
     To enable the examination committee a further understanding of the means whereby the said objective is accomplished as well as the advantages, other objectives, and operation of the most preferred embodiment of the present invention, the brief description of the drawings below are followed by the detailed description of the invention herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric drawing of the invention herein. 
     FIG. 2 is an exploded drawing of the invention herein. 
     FIG. 3 is an isometric drawing of the front cover  1  of the invention herein. 
     FIG. 4 is an isometric drawing of the front cover  1  of the invention herein. 
     FIG. 5 is an isometric drawing of the back cover  2  of the invention herein. 
     FIG. 6 is an isometric drawing of the back cover  2  of the invention herein. 
     FIG. 7 is an isometric drawing of the hatch  3  of the invention herein. 
     FIG. 8 is an isometric drawing of the hatch  3  of the invention herein. 
     FIG. 9 is an exploded drawing of the blade holder mechanism  5  of the invention herein. 
     FIG. 10 is an isometric drawing of the push button  52  of the invention herein. 
     FIG. 11 is an isometric drawing of the push button  52  of the invention herein. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG.  1  and FIG. 2, the improved structure art design knife of the invention herein is comprised of a front cover  1 , a back cover  2 , a hatch  3 , a hatch lock button  16 , a blade holder mechanism  5 , a flat spring  4 , a blade ejection button  25 , a blade  56 , a push button  52 , a cushioning button  8 , an upper grip pad  6 , and a lower grip pad  7 , wherein; 
     Referring to FIG.  3  and FIG. 4, the said front cover  1  is a shell plate of one-piece construction having a semicircular opening  11  in the top edge of its anterior section, a semicircular opening  142  in the bottom edge of the anterior section, and a slide slot  12  along the inside of the top edge; the said front cover  1  also has an elongated recess  13  along the top edge of its posterior section and, furthermore, an elongated opening  18  disposed along the bottom portion of the posterior section and a round tape rule enclosure  181  formed inside the posterior section; additionally, a compartment  14  is formed inside the anterior section of the said front cover  1 , the said compartment  14  having an axial hole  141  at the both upper and lower corners of its forward edge, with the said compartment  14  recessively defined by a trapezoidal frame  143 ; the said front cover  1  has an oval backing plate situated at its middle section, with the said backing plate  15  having an elongated hole  151  at the center and, furthermore, the said backing plate also has a standoff block  17  at the inner side of its rear edge and a fastener hole  171  is formed through the center of the said standoff block  17 ; and a collar hole  19  is disposed through the posterior extremity of the said front cover  1 . The hatch lock button  16  is oval in shape and has a check plate at one extremity of its inner side; furthermore, the said hatch lock button  16  has a standoff block  161  formed at the center of its inner side and a threaded hole  162  is tapped in the center of the said standoff block  161 ; the said locating block  163  is rectangular in shape and has a fastener hole  164  through one side and, furthermore, a blind hole  165  in the other side, with a coil spring  166  inserted into the said blind hole  165 ; the standoff block  161  of the said hatch lock button  16  is inserted into the elongated hole  151  at the center of the backing plate  15  of the front cover  1 , a screw  167  is then inserted into the fastener hole  164  of the locating block  163  and tightened into the threaded hole  162  of the standoff block  161 , enabling the assembly of the coil spring  166  and the locating block  163  such that the hatch lock button  16  is capable of being toggled back and forth on the backing plate  15  of the front cover  1 . 
     Referring to FIG.  5  and FIG. 6, the said back cover  2  is a shell plate of one-piece construction having a semicircular opening  21  in the top edge of its anterior section and a slide slot  22  along the inside of the middle section top edge, with a wave-profiled rack  221  arrayed along the bottom edge of the said slide slot  21 ; the said rear cover  2  also has an elongated recess  23  along the top edge of its posterior section and, furthermore, an elongated opening  28  is disposed along the bottom portion of the posterior section and a round tape rule enclosure  281  is formed inside the posterior section; additionally, a vertically oriented slide channel  24  is formed inside the anterior section of the said back cover  2  and a threaded hole  241  is tapped at the top edge of the said slide channel  24 ; a slide plate  251  extends upward from the said blade ejection button  25 , the said slide plate  251  having an elongated hole  252  through its top edge such that the said elongated hole  252  allows the insertion of a screw  253  which is fastened into the threaded hole  241  at the slide channel  24  of the back cover  2 ; the said back cover  2  has a shaft  26  integrated inside the bottom edge of its anterior section and a coil spring  254  is sleeved over the said shaft  26 , with the extended portion of the said coil spring  254  postured horizontally against the bottom edge at the inner side of the blade ejection button  25  such that the blade ejection button  25  is constrained within the slide channel  24  of the back cover  2 , but capable of shifting upward and downward; the said back cover  2  has a threaded mounting hole  27  at the center of its posterior section and, furthermore, a collar hole  29  is disposed through the posterior extremity of the back cover  2 . 
     Referring to FIG.  7  and FIG. 8, the said hatch  3  is shaped such that it is congruous with the said compartment  14  of the front cover  1 ; the said hatch  3  has a hinge pin  31  formed at each of the upper and lower corners of its anterior side, with the said hatch  3  also having an arcuate catch indentation  32  along the outer edge of the posterior side; additionally, a spring attachment slot  33  is formed at both the anterior and the posterior inner sides of the said hatch  3 ; the said flat spring  4  is a one-piece component with a mounting tab  41  at each of its two ends that is punched fabricated from sheet metal; two overlapping tensile elements  42  crisscross inward on the said flat spring  4 ; and the mounting tabs  41  of the said flat spring  4  are inserted into the spring attachment slots  33  along the inner side of the hatch  3 . 
     Referring to FIG. 9, FIG. 10, and FIG. 11, the said blade holder mechanism consists of a blade carrier  51 , a push button  52 , and a blade arresting component  53 , wherein: 
     The push button  52  has a vertical support member  522  at the lower extent of its body  521 ; a cylindrical post  523  is formed in the center at one side of the body  521  and, furthermore, another cylindrical post  524  is formed on the push button  52  at the lower extent of its anterior edge; and the upper extent of the said push button  52  is surfaced with a pliant lining  525 . 
     The blade arresting component  53  has a semicircular pawl  531  at the bottom edge of its anterior extremity, a cylindrical post  532  is disposed at the center of the upper edge of the said blade arresting component  53  and, furthermore, a support pin  533  emerges from one side at the posterior extremity of the blade arresting component  53  and the said blade arresting component  53  has a rectangular block  534  formed on the lower edge of its anterior section. 
     The blade carrier  51  has a T-shaped insertable element  511  formed along the upper edge of its anterior extremity and a skid element  512  along its lower edge; the said blade carrier  51  has a rectangular recess  513  in the center and, furthermore, a semicircular support pin notch  514  is formed in the upper edge at the posterior extremity of the said blade carrier  51 . 
     The support pin  533  emerging from one side at the posterior extremity of the blade holder mechanism  5  blade arresting component  53  is fitted into the semicircular support pin notch  514  in the upper edge at the posterior extremity of the said blade carrier  51  a coil spring  54  is sleeved between the post  524  of the push button  52  and the post  532  disposed at the center of the blade arresting component  53 ; furthermore, the vertical support member  522  at the lower extent of the said push button  52  is placed through another coil spring  55  and then inserted into the rectangular recess  513  of the blade carrier  51 ; and the pawl  531  at the bottom edge along the anterior extremity of the blade arresting mechanism  53  engages the semicircular notch in the top edge of the blade  56 , thereby securing the blade  56  in the blade holder mechanism  5 . 
     The post  523  at one side of the blade holder mechanism  5  push button  52  of the invention herein is insertionally postured within the wave-profiled rack  221  beneath the upper edge along the anterior section of the back cover  2 ; the said cushioning button  8  is placed into the semicircular opening  11  in the top edge along the anterior section of the front cover  1 ; the said upper grip pad  6  is unitarily fabricated out of a soft plastic material and embedded in a long recess  13  molded in the top edge along the posterior section of the front cover  1 ; the said lower grip pad  7  is also unitarily fabricated of a soft plastic material but embedded in a long recess  18  molded in the bottom portion along the posterior section of the front cover  1 ; furthermore, the two hinge pins  31  of the said hatch  3  are coupled into the axial holes  141  of the front cover  3 , enabling the closing of the hatch  3  over the compartment  14  of the front cover  1 , with the hatch lock button  16  latching the hatch  3  against the front cover  1 ; and the front cover  1  and the rear cover  2  are connected together by inserting a screw  9  through the fastener hole  171  of the front cover  1  and then tightening it into the threaded mounting hole  27  of the back cover  2 , thereby completing the assembly of the art design knife structure. 
     The post  523  of the push button  52  of the invention herein is positioned in the wave-profiled rack  221 ; when the push button  52  is depressed, the post  523  is disengaged from the wave-profiled rack  221  and the push button  52  is impelled outward such that the push button  52  causes the blade carrier  51 , the blade arresting mechanism  53 , and the blade  56  to slide outward; when the blade  56  slides to the appropriate position, the push button  52  is released and the coil springs  54  and  55  of the said push button  52  elastically rebound upward and position the said post  523  back into the wave-profiled rack  221 , thereby achieving a safe and stable blade forwarding operation; to withdraw the blade  56 , the same procedure is conducted in reverse by operating the push button  52  in the opposite direction. 
     To effect blade replacement, the blade ejection button  25  is pressed upward when the blade  56  is pushed beyond the anterior extremity of the art design knife, the top edge of the slide plate  251  of the said blade ejection button  25  lifts the rectangular block  534  at the lower edge along the anterior extremity of the blade arresting component  53 , with the support pin  533  of the said blade arresting component serving as the pivoting axis, causing the pawl  531  at the anterior extremity of the blade arresting mechanism  53  to ascend and disengage from the notch  57  of the blade  56 , thereby allowing the removal of the blade  56 ; the trapezoidal frame  143  in the said front cover  1  contains a plurality of preloaded, stacked blades  56  with the flat spring  4  at the inner side of the hatch  3  tensioned inward against the blades  56  such that the blades  56  are pushed to the very bottom level of the trapezoidal frame  143  and as the said blade arresting mechanism  53  returns, the pawl  531  of the blade arresting mechanism  53  once again engages the notch  57  in the upper edge of the blade  56 , thereby completing the replacement of a blade. 
     In summation of the foregoing section, since the invention herein is capable of achieving the claimed utilization objectives and, furthermore, the disclosed structure possesses exceptional practical value and functionality, the present invention is submitted to the examination committee for review and the granting of the commensurate patent rights.