Abstract:
A secure injector and the operating method thereof are proposed. The secure injector includes: a needle cylinder having a body and a needle socket, the body and the needle socket being hollow bodies forming a containing space; a fixing and maintaining section in the form of a hollow tubular body disposed in the needle socket, the fixing and maintaining section including a ringent first fixed section and a second fixed section without puffing; a metallic needle having a withstanding section, the metallic needle being positioned in the hollow tubular body of the fixing and maintaining section, and withstood in the second fixed section by the withstanding section; and an injecting pole having a magnetic component, wherein the magnetic component of the injecting pole attracts the metallic needle through drawing or pulling out the injecting pole, thereby the metallic needle is retracted into the needle cylinder.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to the secure injector and operating method thereof. More particularly, the present invention relates to the secure injector in which the needle is automatically retracted into the needle cylinder and an operating method thereof.  
       BACKGROUND OF THE INVENTION  
       [0002]     It is a common medical procedure to inject medicine into a patient by needle in order to control illness during the treatment process. However, in the process, medical workers are subjected to the risk of being pricked by the injecting needle and receiving an infection. Therefore, medical workers must be extremely cautious when using injection needles in order to avoid being infected.  
         [0003]     The Republic of China Laid-Open Patent Publication No.M249673 proposes a retracted-mode secure injector having a telescoping drawhook. This secure injector includes a needle cylinder, a needle, and an injecting pole. The injecting pole is composed of a cork, wherein a handspike body and a drawhook component discretely connect the cork with the handspike body. The drawhook component contains a drawhook formed in front of the cork, wherein the drawhook component and the handspike body move in separate directions a specified distance so as to separate the cork from the handspike body by negative pressure formed in the process of drawing in medicine and also the pull imposed on the injecting pole through the structure of a non-return locking pawl. Moreover, by virtue of the thrust imposed on the injecting pole and the friction of the fringe between the cork and the inner wall of the needle cylinder during the injection process, the cork and the handspike body come back to the jogged state, and part of the drawhook protrudes to the front of the cork. Thus, when the cork contacts the inside of the front of the needle cylinder, the drawhook component connects with the needle, such that by pulling back on the injecting pole, the needle can be withdrawn into the containing space of the needle cylinder.  
         [0004]     However, although the above-described conventional retracted-mode secure injector having a telescopic drawhook provides a secure injector capable of retracting the needle to the needle cylinder that avoids the accidental occurrence of medical workers pricking themselves during the process of using the needle cylinder, the structure for such a retracted-mode secure injector having a telescopic drawhook is complex and assembly is not easy. Moreover, the needle is unable to be automatically retracted to the needle cylinder.  
         [0005]     Accordingly, there exists a strong need in the art for fabricating a secure injector with simple structure, easy assembly, and a needle that can be automatically retracted into the needle cylinder.  
       SUMMARY OF THE INVENTION  
       [0006]     Accordingly, it is an objective of the present invention to solve the aforementioned problems by providing a secure injector, wherein the needle can be automatically retracted to the needle cylinder after usage by drawing and pulling out the injecting pole in such a way that the magnetic component set in the injecting pole magnetizes the metallic needle so as to retract the metallic needle to the needle cylinder, thereby avoiding risk to the environment and infection of the hospital staff.  
         [0007]     It is another objective of the present invention to provide a secure injector with the needle automatically retracted to the needle cylinder, wherein a magnetic component and hook are set in the injecting pole, and also a spring unit is set in the needle cylinder, such that, when the hook of the injecting pole engages the spring unit, the spring unit is tensioned, and when the injecting pole is released, the spring unit releases, and, concurrently, the magnetic component of the injecting pole magnetizes the metallic needle, thereby the metallic needle can be automatically retracted to the needle cylinder in order to enhance the safety of the hospital staff by insuring that the hospital staff is protected from being pricked by the metallic needle of the injector.  
         [0008]     It is further objective of the present invention to provide a secure injector with simple structure and easy assembly which protects the hospital staff from being pricked by the metallic needle of a possibly infectious injector and being infected after finishing the injecting process, thereby realizing the objective of a practical method to ensure safety, so as to maintain the personal safety of the hospital staff.  
         [0009]     In order to attain the objectives mentioned above and others, a secure injector according to the present invention comprises: a needle cylinder having a body and a needle socket, the body and the needle socket being hollow structures, wherein a first containing space is sequentially formed in the needle cylinder body and second and third containing spaces are formed in the needle socket, the third containing space extending outside the second containing space; a fixing and maintaining section disposed in the needle socket in the form of hollow tubular body, the fixing and maintaining section including a first fixed section and a second fixed section, the first fixed section being a ringent body; a metallic needle having a withstanding section, the metallic needle being positioned in the hollow tubular body of the fixing and maintaining section, and withstood in the second fixed section of the fixing and maintaining section by the withstanding section; and an injecting pole having a magnetic component, wherein the magnetic component of the injecting pole magnetizes the metallic needle through drawing and pulling out the injecting pole, thereby the metallic needle contained in the fixing and maintaining section is retracted into the needle cylinder.  
         [0010]     In addition, the rear of the needle cylinder extends outside and forms a flange on which a spring unit is set, and a plurality of hooks are set at the axial position of the injecting pole. During injecting, when the hook engages the spring unit and the injecting pole is pushed, the spring unit is tensioned, and when the injecting pole is released, the spring unit releases, and, concurrently, the magnetic component of the injecting pole magnetizes the metallic needle, thereby the metallic needle is automatically retracted into the needle cylinder.  
         [0011]     In order to attain the objectives mentioned above and others, the present invention is directed to an operating method of the aforementioned secure injector, the method includes the following steps: containing the injection in the needle cylinder through the metallic needle according to the injection dosages as required; pushing the injecting pole to make the end with the magnetic component of the injecting pole extrude the injection, thereby performing the injecting of the injection in the needle cylinder; making the first fixed section of the fixing and maintaining section enter from the second containing space to the third containing space and assume a ringent state, so that the metallic needle assumes a loosened state; and making the magnetic component of the injecting pole attract the metallic needle, drawing and pulling out the injecting pole, so that the metallic is retracted to the needle cylinder.  
         [0012]     Furthermore, a hook is set correspondingly at the axial position of the injecting pole and a spring unit is set in the needle cylinder, so that the hook of the injecting pole can engage the spring unit of the needle cylinder, such that, when the injecting pole is pushed for injecting, the spring unit is tensioned towards the injecting pole, and the first fixed section of the fixing and maintaining section enters from the second containing space to the third containing space and assumes a ringent state, thereby the metallic needle assumes a loosened state. Then, when the injecting pole is released, the spring unit retracts to make the injecting pole quickly move in a direction deviating from the first containing space, making the magnetic component of the injecting pole magnetize the metallic needle and move in the drawing and pulling out direction, thereby the metallic needle is automatically retracted into the needle cylinder.  
         [0013]     A secure injector and operating method thereof according to the present invention can efficiently solve the conventional problems caused by the complex structure, difficult assembly, and the inability of the needle to be automatically retracted into the needle cylinder of existing designs, and can concurrently protect the hospital staff from being pricked by the needle of an infectious injector and being infected when administering injections. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The present invention can be more fully understood by reading the following detailed description of the preferred embodiments, with reference made to the accompanying drawings, wherein:  
         [0015]      FIG. 1  is an exploded perspective view of a secure injector according to the present invention;  
         [0016]      FIG. 2  is an assembled cross-sectional view of the secure injector according to the present invention;  
         [0017]      FIG. 3  is an assembled perspective view of the secure injector according to the present invention;  
         [0018]      FIG. 4  is a cross-sectional view of the secure injector when drawing an injection according to the present invention;  
         [0019]      FIGS. 5A and 5B  are cross-sectional views showing the secure injector safely retracting a metallic needle according to the present invention;  
         [0020]      FIG. 6  is a cross-sectional view of the secure injector according to another embodiment of the present invention;  
         [0021]      FIG. 7  is a cross-sectional view of the secure injector when drawing the injection according to another embodiment of the present invention;  
         [0022]      FIG. 8  is a cross-sectional view of the secure injector during injecting according to another embodiment of the present invention; and  
         [0023]      FIGS. 9A and 9B  are cross-sectional views showing the secure injector safely retracting the metallic needle according to another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]     With reference to  FIG. 1 , an exploded perspective is shown of the secure injector according to the present invention. The secure injector according to the present invention  1  comprises a needle cylinder  10  having a needle cylinder body  11  and a needle socket  12 ; a fixing and maintaining section  20  having a first fixed section  21  and a second fixed section  22 ; a metallic needle  30  having a withstanding section  31 ; and an injecting pole  40  having a cork  41 , a magnetic component  42 , and an injecting pole body  43 .  
         [0025]     Continuing reference to  FIG. 1  and matching with  FIG. 2 ,  FIG. 2  depicts a cross section of the secure injector according to the present invention. Two sides of the rear of the needle cylinder  10  extend outside and form a flange  13 , the flange  13  is approximately an oval body, while the needle cylinder body  11  is a hollow body, and the hollow body forms a first containing space  14 , the first containing space  14  of the needle cylinder body  11  being for receiving the injecting pole  40 .  
         [0026]     The needle socket  12  is also a hollow body connecting with the needle cylinder body. The hollow body of the needle socket  12  sequentially forms a second containing space  15  and a third containing space  16 , the third containing space  16  extending outside from the second containing space  15 , so that the inner diameter of the third containing space  16  is larger than that of the second containing space  15 . The second containing space  15  and the third containing space  16  of the needle socket  12  are for placing the fixing and maintaining section  20 , and a beveled portion  17  is set between the second containing space  15  and the third containing space  16 , the third containing space  16  being larger than the second containing space  15  due to the beveled portion  17 . The inside of the needle socket  12  forms a shape that is wide at the top and narrow at the bottom, and the beveled portion  17  is to lead the first fixed section  21  of the fixing and maintaining section  20  into the third containing space  16  in the needle socket  12  of the needle cylinder  10 .  
         [0027]     The fixing and maintaining section  20  is a hollow body for placing the metallic needle  30 . In its natural state, the first fixed section  21  of the fixing and maintaining section  20  is ringent in shape without the effect of applying force. There is a beveled portion  23  between the first fixed section  21  and the second fixed section  22 . The external diameter of the first fixed section  21  of the fixing and maintaining section extends outside from the second fixed section  22  along the beveled portion  23 , such that the external diameter of the first fixed section  21  is larger than the inner diameter of the second containing space  15  in the needle socket  12 , the external diameter of the second fixed section  22  is smaller than the inner diameter of the second containing space  15  in the needle socket  12 , thus, the fixing and maintaining section  20  can be closely contained in the second containing space  15  of the needle socket  12  by the first fixed section  21 , and the first fixed section  21  assumes a closed state due to the application of external force. In addition, the beveled portion  23  of the fixing and maintaining section  20  is matched with the beveled portion  17  between the second containing space  15  and the third containing space  16 . As such, the first fixed section  21  of the fixing and maintaining section  20  easily enters the third containing space  16  under light pressure. The inner diameter of the third containing space  16  is larger than the external diameter of the first fixed section  21 , such that the first fixed section  21  can not be pressed any more by the external force and can assume a ringent state when the first fixed section  21  enters the third containing space  16 . Furthermore, the external diameter of the metallic needle  30  is slightly larger than the inner diameter of the hollow tube of the fixing and maintaining section  20 . The fixing and maintaining section  20  and the needle cylinder  10  can employ plastic material having the plasticity, thereby the metallic needle  30  can be closely gripped in the fixing and maintaining section  20  contained in the needle socket  12  (the second containing space  15 ). Concurrently, the possibility that injection could filter into the inside of the fixing and maintaining section  20  or the interval between the fixing and maintaining section  20  and the needle socket  12  is greatly reduced or avoided.  
         [0028]     A flute  24  for propping the withstanding section  31  of the metallic needle  30  is set at the bottom of the second fixed section  22  of the fixing and maintaining section  20  so that the metallic needle  30  can not slide forward. In addition, the second fixed section  22  can slightly protrude into the first containing space  14  in the needle cylinder body  11  so that the injecting pole  40  can efficiently push the fixing and maintaining section  20  during the process of injecting, and the fixing and maintaining section  20  can move so as to make the first fixed section enter the third containing space  16  in the needle socket  12  and assume a ringent state.  
         [0029]     The injecting pole  40  comprises: a cork  41  at one end having a containing space  45 , a magnetic component  42 , the magnetic component  42  being positioned in the containing space  45  of the cork  41 , and an injecting pole body  43 , the injecting pole body  43  being an axial, cross-shaped rib, but not limited to this design. In addition, the cork  41  at one end of the injecting pole  40  can be formed with a slight bulge  44 , so as to efficiently push the fixing and maintaining section  20  gripped in the second containing space  15  of the needle socket  12 .  
         [0030]     Furthermore, the secure injector further comprises a cover body  50  for combining with the needle socket  12 , so as to cover the metallic needle  30 .  
         [0031]     In a preferred, exemplary embodiment, the metallic needle  30  and the withstanding section  31  are integrally molded, meaning that the rear of the metallic needle  30  extends outward and forms a withstanding section  31  in a one-piece design. The formation of the injecting pole  40  consists of pouring the cork  41  having magnetic material, and then pouring the injecting pole body  43  from plastic material in a pouring mold to form the injecting pole  40  having the magnetic component according to the present invention.  
         [0032]     With reference to  FIG. 3 , shown is a perspective view of the secure injector according to the present invention. In the secure injector  1  of the present invention, the metallic needle  30  is positioned in the hollow tubular body of the fixing and maintaining section  20  through the rear of the fixing and maintaining section  20 . At this time, the withstanding section  31  of the metallic needle  30  butts up against the flute  24  of the fixing and maintaining section  20 , so that the metallic needle can not slide forward and can be disposed in the fixing and maintaining section  20 . The fixing and maintaining section  20  is positioned in the second containing space  15  of the needle socket  12 , and the rear of the fixing and maintaining section  20  protrudes into the needle cylinder body  11 . The first fixed section  21  of the fixing and maintaining section  20  originally assuming a ringent state is closely combined with the needle socket  12  and firmly disposed in the needle socket  12 , and the metallic needle  30  is also firmly disposed in the fixing and maintaining section  20  and can not slide. The magnetic component  42  is positioned in the cork  41  and then combined with the injecting pole body  43 , and the assembled injecting pole  40  is inserted from the rear of the needle cylinder body  11  and disposed in the first containing space  14 .  
         [0033]     With reference to  FIG. 4 , a cross-sectional view is shown of the secure injector when drawing in the injection according to the present invention. When it is desired to draw in the injection  60  using the secure injector  1  of the present invention, the injecting pole  40  is progressively pulled in the direction away from the needle socket  12 . This pulling action forms a negative pressure in the needle cylinder  10 , so that the injection  60  is drawn into the needle cylinder  10 . At this time, the fixing and maintaining section  20  is still positioned in the second containing space  15  of the needle socket  12 , and the metallic needle  30  is firmly positioned in the fixing and maintaining section  20  by virtue of the gripping of the fixing and maintaining section  20 . And when the needle cylinder  10  has the desired amount of injection  60  desired to perform the injection, the injection is administered by slowly pushing the injecting pole  40  progressively into the first containing space  14  until the injecting pole  40  is firmly pushed against the fixing and maintaining section  20 , thereby completing the action of injecting. At this time, the fixing and maintaining section  20  is still in the second containing space  15  of the needle socket  12 , and the metallic needle  30  is firmly positioned in the fixing and maintaining section  20  by virtue of the gripping of the fixing and maintaining section  20 .  
         [0034]     With reference to  FIGS. 5A and 5B , cross-sectional views are shown of the secure injector showing the process of safely retracting the metallic needle according to the present invention in order to avoid the injector from posing a risk of pricking someone. When injecting is finished, applying pressure on the injecting pole  40  firmly abuts it against the bottom of the fixing and maintaining section  20 . This causes the first fixed section  21  of the fixing and maintaining section  20  to be pushed firmly into the third containing space  16  having a relative large space. The bulge  44  of the injecting pole  40  helps to push the fixing and maintaining section  20 . After being pushed sufficiently, the first fixed section  21  assumes a ringent state, and the metallic needle  30  then assumes a loosened state due to the opening of the first fixed section  21 . Then, through drawing out the injecting pole  40 , the magnetic component  42  of the injecting pole  40  attracts the metallic needle  30  and makes the metallic needle  30  move in the drawing and pulling out direction, thereby the metallic needle  30  is contained in the needle cylinder  10 , attaining the feature of a secure injector.  
         [0035]     With reference to  FIG. 6 , a cross-sectional view is shown of the secure injector according to another embodiment of the present invention. Components that are identical or similar to the above exemplary embodiment are given the same or similar component reference numerals. For conciseness, detailed descriptions for components identical to the above embodiment are omitted.  
         [0036]     The secure injector according to the present invention comprises a needle cylinder  10  having a needle cylinder body  11  and a needle socket  12 . A spring unit  18  is set at the rear of the needle cylinder  10 . The secure injector further comprises: a fixing and maintaining section  20  having a first fixed section  21  and a second fixed section  22 ; a metallic needle  30  having a withstanding section  31 ; and a injecting pole  40  having a cork  41 , a magnetic component  42 , an injecting pole body  43 , and a plurality of hooks  46  axially set along the injecting pole body.  
         [0037]     Two sides of the rear of the needle cylinder  10  extend outside and form a flange  13 , and the spring unit  18  is set on the flange  13 . The needle cylinder body  11  is a hollow body, and the hollow body forms a first containing space  14 , the first containing space  14  of the needle cylinder body  11  being for placing the injecting pole  40  and containing the injection  60 .  
         [0038]     The needle socket  12  is also a hollow body forming a second containing space  15  and a third containing space  16 , the second containing space  15  and the third containing space  16  of the needle socket  12  being for placing the fixing and maintaining section  20 . There is a beveled portion  17  between the second containing space  15  and the third containing space  16 , the third containing space  16  being larger than the second containing space  15  due to the beveled portion  17 . The inside of the needle socket  12  forms a shape that is wide at the top and narrow at the bottom.  
         [0039]     The fixing and maintaining section  20  has a hollow tube for placing the metallic needle  30 . A beveled portion  23  matching with the beveled portion  17  between the second containing space  15  and the third containing space  16  is also set between the first fixed section  21  and the second fixed section  22 , so that the first fixed section  21  of the fixing and maintaining section  20  easily enters the third containing space  16  of the needle socket  12 , and, in its natural state, the first fixed section  21  of the fixing and maintaining section  20  is ringent in shape. A flute  24  for propping the withstanding section  31  of the metallic needle  30  is set at the bottom of the second fixed section  22 , so that the metallic needle  30  can not slide forward. In addition, the beveled portion  17  of the aforementioned needle socket  12  is used to lead the first fixed section  21  of the fixing and maintaining section  20  into the third containing space  16  of the needle socket  12  and make the first fixed section  21  assume a ringent state. The withstanding section  31  at one end of the metallic needle  30  withstands in the second fixed section  22  of the fixing and maintaining section.  
         [0040]     The external diameter of the first fixed section  21  is larger than the inner diameter of the second containing space  15  in the needle socket  12 . The external diameter of the second fixed section  22  is smaller than the inner diameter of the second containing space  15  in the needle socket  12 , thus, the fixing and maintaining section  20  can be closely contained in the second containing space  15  of the needle socket  12  by the first fixed section  21 , and the first fixed section  21  assumes a closed state due to the application of external force. In addition, the beveled portion  23  of the fixing and maintaining section  20  is matched with the beveled portion  17  between the second containing space  15  and the third containing space  16 , thereby the first fixed section  21  of the fixing and maintaining section  20  can be pushed easily to enter the third containing space  16 . The inner diameter of the third containing space  16  is larger than the external diameter of the first fixed section  21 , so that the first fixed section  21  can not be pressed further by external force and can assume a ringent state when the first fixed section  21  enters the third containing space  16 . Furthermore, the external diameter of the metallic needle  30  is slightly larger than the inner diameter of the hollow tube of the fixing and maintaining section  20 . The fixing and maintaining section  20  and the needle cylinder  10  can employ plastic material having plasticity, thereby the metallic needle  30  can be closely gripped in the fixing and maintaining section  20  contained in the needle socket  12  (the second containing space  15 ), and, concurrently, injection filtering into the inside of the fixing and maintaining section  20  or the interval between the fixing and maintaining section  20  and the needle socket  12  is greatly reduced or avoided.  
         [0041]     The injecting pole  40  comprises: a cork  41  positioned at the front end having a containing space  45 , a magnetic component  42  formed in the containing space  45  of the cork  41 , and an axial injecting pole body  43  that is cross-shaped, but it is not limited to this. In addition, the cork  41  at one end of the injecting pole  40  can be formed with a slight bulge  44 , so as to better push the fixing and maintaining section  20  gripped in the second containing space  15  of the needle socket  12 .  
         [0042]     Furthermore, a plurality of hooks  46  is set at one side of the injecting pole  40  (on one of the axial, cross-shaped ribs). The distribution of the plurality of the hooks  46  is according to the various injection dosages typically used for injections. That is, the plurality of hooks  46  are set at positions with different interval lengths, e.g., according to the scale of 5 cc, 10 cc, 15 cc, 20 cc etc. in the needle cylinder. Thus, the most rearward hook of the plurality of hooks  46  positioned on one of the axial, cross-shaped ribs corresponds to an injection dosage of 5 cc; the next hook corresponds to an injection dosage of 10 cc; and so forth. The hooks  46  are used to engage the spring unit  18 . In addition, the design of the hooks  46  assumes a barbed, oblique shape, such that, when the injecting pole  40  moves towards the rear opening of the needle cylinder during the process of drawing in an injection, the hooks can not engage the spring unit  18  and prevent the injecting pole  40  from moving. Correspondingly, when the injecting pole  40  moves towards the needle socket  12  during the process of injecting an injection into the recipient, the injecting pole  40  engages the spring unit  18  by the hooks  46  to tension the spring. Subsequently, the injecting pole  40  is automatically retracted by the stored energy in the spring unit  18  when injecting is finished and the injection pole  40  is released by the user administering the injection.  
         [0043]     Continuing reference to  FIG. 6  and matching with  FIG. 7 ,  FIG. 7  depicts a cross-sectional view of the secure injector when drawing the injection according to another embodiment of the present invention. When it is desired to draw in an injection  60  using the secure injector  1  of this embodiment, firstly, drawing out the injecting pole  40  away from the needle socket  12  creates a negative pressure in the needle cylinder  10 , such that the injection  60  is drawn into the needle cylinder  10 . At this time, the fixing and maintaining section  20  is still positioned in the second containing space  15  of the needle socket  12 , and the metallic needle  30  is firmly positioned in the fixing and maintaining section  20  by virtue of the gripping of the fixing and maintaining section  20 .  
         [0044]     With reference to  FIG. 8 , a cross-sectional view is shown of the secure injector at the moment of injecting according to another embodiment of the present invention. When it is desired to perform an injection with the needle cylinder  10  filled with an injection  60 , the angle of the injecting pole  40  is adjusted, so that one side having a hook  46  of the injecting pole  40  vertically crosses with the flange  13 , such that the position of the hook  46  is selected according to the desired injection dosage, and the selected hook  46  of the injecting pole  40  hitches the spring unit  18  of the flange  13 . At this time, if the hook  46  of the injecting pole  40  is set to correspond to the stack shell of the needle cylinder, the hook  40  can engage the spring unit  18 . Then, the injecting pole  40  is pushed to administer the injection, typically until completely finishing injecting the injection  60 , during which the spring unit  18  tensions the spring due to the pressure of pushing until the injecting pole  40  is firmly pushed to the bottom of the fixing and maintaining section  20 , thereby completing the action of injecting. At this time, the fixing and maintaining section  20  is still in the second containing space  15  of the needle socket  12 , and the metallic needle  30  is firmly positioned in the fixing and maintaining section  20  by virtue of the gripping of the fixing and maintaining section  20 .  
         [0045]     With reference to  FIGS. 9A and 9B , cross-sectional views are shown of the secure injector safely retracting the metallic needle according to another embodiment of the present invention in order to avoid the needle from being exposed and possibly pricking someone and causing infection. At the time that the injector finishes the injection, pressure is being applied to the injecting pole  40  to firmly press it the bottom of the fixing and maintaining section  20 . The first fixed section  21  of the fixing and maintaining section  20  is pushed to the third containing space  16  with a relatively large space such that the bulge  44  of the injecting pole  40  withstands and pushes the fixing and maintaining section  20  or because that the fixing and maintaining section  20  slightly protrudes to the inside of the needle cylinder, and the first fixed section  21  can not be constrained any more by the external force and can assume a ringent state. At this time, the metallic needle  30  assumes a loosened state due to the opening of the first fixed section  21 , while the injector can unloosen by the finger pushing the injecting pole  40 , so that the spring unit  18  is released and retracts to make the injecting pole  40  flick towards the direction deviating from the first containing space  14 . The magnetic component  42  of the injecting pole  40  concurrently magnetizes and attracts the metallic needle  30 , and the metallic needle  30  can move in the drawing out direction of the injecting pole  40 , thereby containing the metallic needle  30  in the needle cylinder, and attaining the feature of secure injector with the metallic needle  30  automatically retracted to the needle cylinder  10 .  
         [0046]     The present invention has been described using exemplary preferred embodiments. However, it is to be understood that the scope of the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements. The scope of the claims, therefore, should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.