Abstract:
A disposable safety syringe designed to prevent syringe handlers from being pricked by a needle by covering the needle with a needle shield, is provided. Special attention should be given to syringe needles because they are sharp enough to cause needle stick injuries before and after use. In particular, if a user is accidentally injured by a blood-stained needle, serious infections might be caused through the needle. Accordingly, the needle is covered with the needle shield after use. The needle shield is fitted over a syringe cylinder. A stopping tab prevents the needle shield from sliding off the cylinder. Inserting tabs are formed by cutting part of shield walls, and locking grooves are formed in the end of the inserting tabs. A fixing adapter has an engagement sill formed in the inner side thereof and a number of elastic fins in the outer side thereof, which is fitted on the locking tab of the needle fixer.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a disposable safety syringe designed to prevent syringe handlers from being pricked by a needle by covering the needle with a needle shield.  
         [0003]     2. Description of the Related Art  
         [0004]     Disposable safety syringes are widely used due to the concerns that infectious diseases such as hepatitis and AIDS virus may be transmitted to a third party via needles of used syringes. However, the needles should be handled with much care before and after use because they are very sharp.  
         [0005]     In particular, blood-stained needles may cause infections or injuries to medical practitioners such as doctors and nurses, or a third party who are pricked by the needles due to careless handling.  
         [0006]     Thus, it is required that a safety syringe that is used single-time and disposable safely. That is, it is required that the safety syringe is designed to prevent sharp needles from causing injuries to medical practitioners or a third party by covering the needles with needle shields.  
         [0007]     The prior art inventions of the same inventor as that of this invention are Korea Utility Model Registration Nos. 254002 entitled “Disposable safety syringe,” 195390 entitled “Safety syringe,” and 166124 entitled “Safety syringe,” and 245065 entitled “Disposable safety syringe.” 
       SUMMARY OF THE INVENTION  
       [0008]     To solve the above problems, it is an object of the present invention to provide a disposable safety syringe with a built-in needle shield which is installed in the outside of a syringe cylinder, and can be slidably moved over a needle, in which the needle shield is pushed forward over the needle and locked to protect the needle inside thereof after use.  
         [0009]     It is another object of the present invention to provide a disposable safety syringe with a needle-protection shield which can remove the concerns that used needles may cause infections to medical parishioners such as doctors and nurses, and a third party, since special attention should be given to syringe needles because they are sharp enough to cause needle stick injuries, and in particular, if a user is accidentally injured by a blood-stained needle, serious infections might be caused through the needle.  
         [0010]     According to an aspect of the present invention, there is provided a disposable safety syringe for use as a non-detachable disposable syringe having a built-in needle which is fixed inside a needle fixer at the distal end of a syringe cylinder or a detachable disposable syringe having a separate needle which should be assembled with a needle fixer, which has a plunger provided on the inner face of the syringe cylinder, the disposable safety syringe comprising:  
         [0011]     a locking tab formed at the needle fixer of both types of syringes;  
         [0012]     a cylinder-shaped movable needle shield which is slidably moved along the cylinder and is fitted on the outer surface of the cylinder;  
         [0013]     a stopping tab which prevents the needle shield from sliding off the cylinder at the leading end of the needle shield;  
         [0014]     inserting tabs formed by cutting part of shield walls at the rear end of the needle shield, in which each inserting tab includes an elastic piece and a support piece between which a cut-off gap is formed, wherein the support piece has a coupling groove therein;  
         [0015]     locking grooves formed in the end of the inserting tabs;  
         [0016]     a number of front-end protrusions and a number of rear-end protrusions formed on the inner side of the needle shield;  
         [0017]     a cylinder grip formed in the rear end of the cylinder;  
         [0018]     a hole formed on the inner face of the cylinder grip to lock with the inserting tabs of the rear end of the needle shield; and  
         [0019]     a fixing adapter having an engagement sill formed in the inner side thereof and a number of elastic fins in the outer side thereof, which is fitted on the locking tab of the needle fixer.  
         [0020]     Preferable but not necessarily, the disposable safety syringe further comprises triangular guiders which guide the inserting tabs of the needle shield and are formed at both left and right sides on the surface of the cylinder, respectively. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     The above and other objects and advantages of the present invention will become more apparent by describing the preferred embodiment thereof in more detail with reference to the accompanying drawings in which:  
         [0022]      FIG. 1  is a perspective view of a disposable safety syringe according to the present invention immediately before use;  
         [0023]      FIG. 2  is a perspective view of the disposable safety syringe of  FIG. 1  immediately after use;  
         [0024]      FIG. 3  is a perspective view of the disposable safety syringe whose needle shield is pushed forward to cover the needle of the disposable safety syringe after use;  
         [0025]      FIG. 4  is an exploded perspective view of the disposable safety syringe with a non-detachable needle;  
         [0026]      FIG. 5  is an exploded cross-sectional view of the disposable safety syringe with a non-detachable needle;  
         [0027]      FIG. 6  is an exploded perspective view of the disposable safety syringe with a detachable needle;  
         [0028]      FIG. 7  is an exploded cross-sectional view of the disposable safety syringe with a detachable needle;  
         [0029]      FIG. 8A  is a cross-sectional view of the disposable safety syringe with a non-detachable needle before use;  
         [0030]      FIG. 8B  is a cross-sectional view of the disposable safety syringe with a non-detachable needle after use and with its needle shield being pushed forward;  
         [0031]      FIG. 8C  is a cross-sectional view of the disposable safety syringe with a non-detachable needle after use and with its protection shield being fixed;  
         [0032]      FIG. 8D  is an enlarged cross-sectional view of a portion “a” of  FIG. 8C ;  
         [0033]      FIG. 9A  is a cross-sectional view of the disposable safety syringe with a detachable needle before use;  
         [0034]      FIG. 9B  is a cross-sectional view of the disposable safety syringe with a detachable needle after use and with its protection shield being pushed forward;  
         [0035]      FIG. 9C  is a cross-sectional view of the disposable safety syringe with a detachable needle after use and with its protection shield being fixed;  
         [0036]      FIG. 9D  is an enlarged cross-sectional view of a portion “a” of  FIG. 8C ;  
         [0037]      FIG. 10  is a perspective view of parts of the disposable safety syringe according to the present invention;  
         [0038]      FIG. 11  is a respective cross-sectional view of an A-A line and a B-B line of  FIG. 10 ;  
         [0039]      FIG. 12  is an enlarged cross-sectional view showing a connection state of joints of the disposable safety syringe;  
         [0040]      FIG. 13  is a lateral view of  FIG. 12 ;  
         [0041]      FIG. 14  is a cross-sectional view of a fixed adapter for use in the disposable safety syringe with a non-detachable deposable syringe;  
         [0042]      FIG. 15  is a cross-sectional view of a fixed adapter for the disposable safety syringe with a detachable deposable syringe;  
         [0043]      FIG. 16  is a crow-sectional view showing a needle shield for use in a disposable safety syringe according to an other embodiment of the present invention;  
         [0044]      FIG. 17  is a cross-sectional view and partially enlarged view showing a needle shield for use in a disposable safety syringe according to still another embodiment of the present invention;  
         [0045]      FIG. 18  is an exploded perspective view of the disposable safety syringe with a detachable needle in which another example of an inserting tab of a needle shield is shown in detail;  
         [0046]      FIG. 19  is a cross-sectional view showing the disposable safety syringe in which triangular guiders are formed on the outer surface of the cylinder so that a needle shield can be easily combined at the rear end of the cylinder;  
         [0047]      FIGS. 20A  to  20 D are partially cross-sectional views showing the disposable safety syringe according to the present invention, for explaining a process of coupling the inserting tab of the needle shield into a hole formed in the inner side of a cylinder grip; and  
         [0048]      FIGS. 21A  to  21 D are partially cross-sectional views showing the disposable safety syringe according to the present invention, for explaining a process of decoupling the inserting tab of the needle shield from the hole formed in the inner side of the cylinder grip. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0049]     Hereinbelow, a disposable safety syringe according to preferred embodiments of the present invention will be described with reference to the accompanying drawings.  
         [0050]     Referring to  FIGS. 1 through 17 , on the inner face of a syringe cylinder  11  is formed a plunder  12 . Here, anon-detachable disposable syringe has a built-in needle which is fixed inside a needle fixer  13  at the distal end of the syringe cylinder  11 . A detachable disposable syringe has a separate needle  15  which should be assembled with the needle fixer  13 . Both types of syringes have locking tabs  16  at the needle fixer  13  of the syringes  11 . A cylinder-shaped movable needle shield  31  is fitted over the cylinder  11  of the syringe. At the front end of the needle shield  31  is formed a stopping tab  32  which prevents the shield from sliding off the cylinder  11 . Shield walls at the rear end of the needle shield  31  are cut to form front and rear inserting tabs  33 .  
         [0051]     At the outside of the inserting tabs  33  are formed locking grooves  34  and on the inner side of the needle shield  31  are formed a number of front-end protrusions  35  and a number of rear-end protrusions  36 . At the rear end of the cylinder  11  has a cylinder grip  17  which has holes  18  on the inner face of the cylinder grip  17  to lock with inserting tabs  33  of the needle shield  31 . A locking tab  16  of the needle fixer  13  is locked with an engagement sill  23  of a fixing adapter  21  when the locking tab  16  is inserted into the adapter  21 .  
         [0052]     On the inner face of the adapter  21  is formed the engagement sill  23  and at the outer face of the adapter  21  are formed a number of elastic fins  22 , for example, 4 to 10 elastic fins. That is, the fixing adapter  21  having the engagement sills  23  inside and the number of elastic fins  22  outside, is pushed over the locking tabs  16  of the needle fixer  13  to be jointed with the locking tabs  16 .  
         [0053]     On the inner face of the number of elastic fins  22  of the fixing adapter  21  is formed a cylinder-shaped wall  24  which has a screw-shaped sills  25  to hold the syringe needle tightly.  
         [0054]     On the inner face of the cylinder-shaped needle shield  31  are formed a number of front protrusions  35  and a number of rear protrusions  36  which have both tilted sides  35 - 1  and  36 - 1  and vertical sides  35 - 2  and  36 - 2 .  
         [0055]     A reference numeral  20  denotes a piston packing which is inserted into the plunger  12 .  
         [0056]     More detailed description of the present invention and its functions are as follows.  
         [0057]     Most of the disposable syringes are categorized into two types. One is a disposable syringe with a non-detachable needle in a needle fixer  13  at the front end of a syringe cylinder  11 . The other has a detachable needle  15  which should be assembled into a needle fixer  13  at the front end of a syringe cylinder  11  immediately before use.  
         [0058]     Non-detachable needles are mostly used for small sized disposable syringes (less than 3 cc) and detachable types are for middle and large sized syringes.  
         [0059]     For detachable syringes, needles are tapped into needle fixers at the front end of syringe cylinders or spun into screws of the needle fixers.  
         [0060]     The present invention can be used with both non-detachable disposable syringes and detachable disposable syringes.  
         [0061]     When a cylinder-shaped needle shield  31  is pushed in over a syringe cylinder  11 , the locking grooves  34  of the inserting tabs  33  of the needle shield  31  are fixed into the inserting holes  18  on the inner face of the grip  17  formed in the rear end of the cylinder  11 , and then the engagement sills  23  in the inner side of the fixing adapter  21  are engaged with the locking tabs  16  of the needle fixer  13  so that the fixing adapter  21  is fixedly engaged with the needle fixer  13 .  
         [0062]     This invention is to deliver fluids to a patient through the syringe needle  15  by pushing the plunder  12  into the syringe cylinder  11 . After use, the cylinder-shaped needle shield  31  over the outer face of the cylinder  11  is pushed forward to cover the needle  15  and fixed to prevent needle stick injuries.  
         [0063]     At the front end of the cylinder  11  is formed the needle fixer  13  which has the locking tab  16 . The locking tab  16  is locked with the engagement sill  23  of the fixing adapter  21 .  
         [0064]     Since the engagement sill  23  of the fixing adapter  21  and the locking tab  16  of the needle fixer  13  are firmly engaged with each other, it is not so easy to detach the adapter  21  from the needle fixer  13  after being locked.  
         [0065]     The fixing adapter  21  has a number of elastic fins  22 , for example, elastic fins  22  of 4˜10 pieces and stopping tabs  26  at the rear ends of the number of elastic fins  22 .  
         [0066]     On the inner sides of the number of elastic fins  22  of the fixing adapter  21  is formed a cylinder-shaped wall  24 . On the inner circumferential surface of the wall  24  are formed screws  25  to hold the syringe needle  15  tightly. A needle  15  of a detachable disposable syringe is spun along the screws  15  on the inner face of the cylinder-shaped wall  24  of the fixing adapter  21  into the needle fixer  13 . Otherwise, the needle  15  is tapped in to the needle fixer  13 , in order to be fixedly engaged with each other.  
         [0067]     The cylinder-shaped needle shield  31  is slidably movable over the syringe cylinder  11 . The rear-end wall of the needle shield  31  is cut to have two inserting tabs  33  each at the end of which has a locking groove  34 . The locking grooves  34  are locked with the inserting holes  18  on the inner face of the grip  17  of the syringe cylinder  11 . By depressing the inserting tabs  33 , the locking grooves  34  are detached from the inserting holes  18  of the syringe cylinder grip  17 . Thus, if a user pushes forward the needle shield  31  (toward the needle) while pushing down the inserting tab  33 , the needle shield  31  is moved forward over the syringe needle  15 .  
         [0068]     The needle shield  31  which moves toward the needle  15  is pushed forward until protrusions  35  on the inner face of the shield  31  meet stopping sills  26  at the rear end of the fixing adapter  21 . Then, if the needle shield  31  is pushed forward with a small amount of force, the front-end protrusions  35  meet the front ends of the number of elastic fins  22  of the fixing adapter  21 . When the rear-end protrusions  36  of the shield  31  meet the stopping sills  26  at the rear end of the elastic fins  22 , the needle shield  31  is fixedly secured so that it is not moved forward and backward any more.  
         [0069]     That is, the needle shield  31  moves forward and fixedly stopped until the fixing adapter  21  is securely locked between the front-end protrusions  35  and the rear-end protrusions  36 .  
         [0070]     In other words, the shield  31  should be pushed forward over the syringe cylinder  11  until the elastic fins  22  of the fixing adapter  21  which is fixed with the needle fixer  13  are locked between the front-end protrusions  35  and the rear-end protrusions  36  on the inner face of the needle shield  31 . If the needle shield  31  is firmly fitted, the needle  15  is covered with the needle shield  31  to prevent needle stick injuries.  
         [0071]      FIG. 18  is an exploded perspective view of the disposable safety syringe with a detachable needle in which another example of an inserting tab of a needle shield is shown in detail.  FIG. 19  is a cross-sectional view showing the disposable safety syringe in which triangular guiders are formed on the outer surface of the cylinder so that a needle shield can be easily combined at the rear end of the cylinder.  
         [0072]     The disposable safety syringe with a detachable needle shown in  FIG. 18  is similar to disposable safety syringe with a non-detachable needle shown in  FIG. 4 . Since the disposable safety syringe adopts a detachable needle shown in  FIG. 18 , a fixing adapter  21  is fixed to a needle fixer  13  located at the end of a cylinder  11  so that only a needle  15  can be detached from the fixing adapter  21 , but since the disposable safety syringe adopts a non-detachable needle shown in  FIG. 19 , the fixing adapter  21  which is integrated with a needle is fixed to a needle fixer  13  located at the end of a cylinder  11 , but only a needle  15  cannot be detached from the fixing adapter  21 . Since the elements of the  FIG. 18  disposable safety syringe except for inserting tables  33  and triangular guiders  11 - 1  are same as those of the  FIG. 4  disposable safety syringe, the detailed description thereof will be omitted.  
         [0073]     According to  FIG. 18 , inserting tabs  33  are formed by cutting part of shield walls at the rear end of a needle shield  31 . Each inserting tab  33  includes an elastic piece  37  and a support piece  38  between which a cut-off gap is formed. The support piece  38  has a coupling groove  39  therein so as to be coupled with a hole  18  formed on the inner face of a cylinder grip  17  to lock with the inserting tabs  33  of the rear end of the needle shield  31 . As shown in detail in a circle “A” in  FIG. 18 , the inserting tabs  33  are symmetrically formed at the end of the needle shield  31 , and the ends of the elastic piece  37  and the support_piece  38  are formed to have slopes  37 - 1  and  38 - 2  whose ends are sharply pointed, respectively.  
         [0074]     According to  FIG. 19 , triangular guiders  11 - 1  which guide the inserting tabs  33  of the needle shield  31  are formed at both left and right sides on the surface of the cylinder  11 , respectively.  
         [0075]      FIGS. 20A  to  20 D are partially cross-sectional views showing the disposable safety syringe according to the present invention, for explaining a process of coupling the inserting tab of the needle shield into a hole formed in the inner side of a cylinder grip.  
         [0076]     As shown in  FIGS. 20A  to  20 D, when the inserting tabs  33  are fitted into a hole  18  formed in the cylinder grip  17 , the slopes  37 - 1  and  38 - 1  respectively formed at the ends of the elastic pieces  37  and the support pieces  38  allow the inserting tabs  33  to be easily fitted into the hole  18 . In this case, the elastic pieces  37  are elastically deformed to have the inserting tabs  33  easily fitted into the hole  18 . Then, coupling grooves  39  respectively formed in the support pieces  38  are coupled with the cylinder grip  17  so that the inserting tabs  33  are not easily detached from the hole  18  formed in the grip  17 .  
         [0077]      FIGS. 21A  to  21 D are partially cross-sectional views showing the disposable safety syringe according to the present invention, for explaining a process of decoupling the inserting_tab of the needle shield from the hole formed in the inner side of the cylinder grip.  
         [0078]     As shown in  FIGS. 21A  to  21 D, in order to detach the inserting tabs  33  from the hole  18  formed in the cylinder grip  17 , the cylinder  11  or the needle shield  31  is rotated. Then, the needle shield  31  is pushed toward the needle  15 . Then, the needle  15  is covered with the needle shield  31 .  
         [0079]     Meanwhile, since the other operations and functions of the needle shield  31  to cover the needle  15  are same as those of  FIGS. 8 and 9 , the detailed description thereof will be omitted.  
         [0080]     As described above, according to an aspect of the present invention shown in  FIG. 4 , when the needle shield  31  is coupled with and detached from the cylinder  11 , the inserting tabs  33  formed at the rear end of the needle shield  31  are depressed and pushed into and out of a hole  18  formed in the grip  17 . Meanwhile, according to another aspect of the present invention shown in  FIG. 18 , when the needle shield  31  is coupled with and detached from the cylinder  11 , the inserting tabs  33  formed at the rear end of the needle shield  31  are pushed into and out of the hole  18  formed in the grip  17 , while the cylinder  11  or the needle shield  31  is rotated.  
       INDUSTRIAL APPLICABILITY  
       [0081]     Special attention should be given to sharp needles before and after use because the needles may be contaminated by a patient&#39;s blood which can carry infectious diseases to the others who were accidentally injured by the needles.  
         [0082]     Thus, the present invention provides a disposable safety syringe having an effect of preventing needle stick injuries with a needle shield which is released from a syringe cylinder before use and pushed forward over the syringe cylinder after use, until the needle shield securely covers the used needle, to thereby prevent any infections from contaminating medical practitioners such as doctors and nurses, and a third party, through the used needles.