Patent Publication Number: US-2023138069-A1

Title: Safety syringe capable of being used for needle-free dosing injection

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a safety syringe and more particularly, to a safety syringe that can be used for needle-free dosing injection. 
     2. Description of the Related Art 
     As far as a conventional safety syringe is concerned, after injection, a push rod and a needle seat are engaged with each other by means of a special structural design, such that the push rod can be pulled into an injection barrel together with the needle seat and a needle, preventing medical personnel or medical waste handlers from being injured by the used needle accidentally. However, after use of the needle, since the needle seat and the needle can&#39;t be separated from each other, the medical personnel will throw away the needle seat and the needle together. Although the needle has been used, the structure of the injection barrel is usually still intact. This will cause waste of material and increase manufacturing costs. 
     SUMMARY OF THE INVENTION 
     It is a primary objective of the present invention to provide a safety syringe, which can be used with a needle-free dosing connector for enhancing convenience of use and reducing waste of material. 
     To attain the above objective, the safety syringe of the present invention comprises a needle seat, an adapter, an injection barrel, and an outer sleeve. The front end of the needle seat is adapted for mounting a needle, and the rear end of the needle seat has a first shaft hole. The adapter has a second shaft hole through its front and rear ends. The second shaft hole of the adapter is sleeved on the rear end of the needle seat, and the second shaft hole of the adapter communicates coaxially with the first shaft hole of the needle seat, An elastic wing is provided at the outer surface of the adapter, The injection barrel has a barrel body and a shaft portion integrally connected with the front end of the barrel body and detachably penetrated into the first shaft hole of the needle seat and the second shaft hole of the adapter. The outer sleeve has a front opening and a rear opening, and the inner surface of the outer sleeve has a first annular rib adjacent to the front opening and a second annular rib adjacent to the rear opening. The outer sleeve is sleeved on the injection barrel and movable along the axial direction of the injection barrel. 
     When liquid medicine is drawn, the outer sleeve is pulled backwards to a first position where the first annular rib of the outer sleeve is engaged with the elastic wing of the adapter, such that the outer sleeve is sleeved on the barrel body of the injection barrel, and the needle seat and the needle are allowed to protrude from the front opening of the outer sleeve. At this time, the needle can enter a medicine bottle, and the liquid medicine is drawn into the injection barrel by using a push rod penetrated into the injection barrel. After drawing of the liquid medicine, there are two different ways to inject the liquid medicine. The first way is to push the push rod for performing injection of the liquid medicine through the needle. The second way is to push forwards the outer sleeve to a second position where the outer sleeve accommodates the needle seat and the adapter inside, Thereafter, the outer sleeve is pushed continuously to push against the elastic wind of the adapter through the second annular rib, such that the outer sleeve is detached from the injection barrel together with the needle seat, the needle, and the adapter. At this time, the shaft portion of the injection barrel is connected with a needle-free dosing connector, and then the push rod is pushed to perform injection of the liquid medicine. 
     It can be understood from the above illustration that the outer sleeve is pulled to the second position before the liquid medicine is drawn for preventing others from being injured by the needle. When the liquid medicine is drawn, the outer sleeve is pulled to the first position to expose the needle for facilitating drawing of the liquid medicine, After drawing of the liquid medicine, the liquid medicine is injected by using the needle or the needle-free dosing connector according to actual needs for enhancing convenience of use. 
     Preferably, the outer surface of the needle seat has an outer flange, The inner surface of the adapter has an inner flange interfered with the outer flange of the needle seat to prevent the needle seat from being separated from the adapter through the top end of the second shaft hole. 
     Preferably, the outer surface of the barrel body of the injection barrel has an elongated rib forced against the second annular rib of the outer sleeve when the outer sleeve is located at the first position for performing the positioning of the outer sleeve. 
     Preferably, the inner surface of the outer sleeve has a third annular rib adjacent to the second annular rib and located between the first annular rib and the second annular rib. When the outer sleeve is located at the second position, the elastic wing of the adapter is located between the second annular rib and the third annular rib for ensuring the needle to be received in the outer sleeve. 
     Preferably, the inner diameter of the second annular rib is greater than the inner diameter of the first annular rib and the inner diameter of the third annular rib, As such, the first annular rib or the third annular rib can be allowed to easily pass through the elastic wing of the adapter without applying too much force to the outer sleeve. 
     Other advantages and features of the present invention will be fully understood by reference to the following specification in conjunction with the accompanying drawings, in which like reference signs denote like components of structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an assembled sectional plan view of a safety syringe of the present invention. 
         FIG.  2    is an exploded sectional plan view of the safety syringe of the present invention. 
         FIG.  3    is a bottom view of an adapter provided by the safety syringe of the present invention. 
         FIG.  4    is a sectional view taken along line  4 - 4  of  FIG.  3   , 
         FIG.  5    is similar to  FIG.  1   , showing that the outer sleeve is located at the second position. 
         FIG.  6    is similar to  FIG.  5   , showing that the outer sleeve is detached from the injection barrel together with the needle, the needle seat, and the adapter. 
         FIG.  7    is another assembled sectional plan view of the safety syringe of the present invention, showing that liquid medicine is drawn through the needle. 
         FIG.  8    is similar to  FIG.  7   , showing that liquid medicine is injected through the needle. 
         FIG.  9    is another assembled sectional plan view of the safety syringe of the present invention, showing that the outer sleeve is detached from the injection barrel together with the needle, the needle seat, and the adapter after performing drawing of the liquid medicine. 
         FIG.  10    is similar to  FIG.  9   , showing that the shaft portion of the injection barrel is connected with a needle-free dosing connector. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS.  1  and  2   , a safety syringe  10  of the present invention comprises a needle seat  20 , an adapter  30 . an injection barrel  40 , a push rod  45 , and an outer sleeve  50 . 
     As shown in  FIG.  2   , the front end of the needle seat  20  is used for mounting with the rear end of a needle  12 . The rear end of the needle seat  20  has a first shaft hole  22 , and the outer surface of the rear end of the needle seat  20  has an outer flange  24 . 
     As shown in  FIGS.  3  and  4   , the adapter  30  has a lager annular portion  31 , a small annular portion  32 , and a second shaft hole  33  through the lager annular portion  31  and the small annular portion  32 . Three pairs of notches  34  are provided at the outer surface of the large annular portion  31 , An elastic wing  35  is formed between the two adjacent notches  34 . The three elastic wings  35  are arranged in an equally-spaced manner relative to the second shaft hole  33 . The inner surface of the large annular portion.  31  has a baffle  36  protruding along the radial direction of the second shaft hole  33 . In addition, the inner surface of the small annular portion  32  has an inner flange  37  extending along the radially direction of the second shaft hole  33 . As shown in  FIGS.  1  and  2   , the second shaft hole  33  of the adapter  30  is sleeved on the rear end of the needle seat  20 , and the inner flange  37  is interfered with the outer flange  24  of the needle seat  20 . By this way, the adapter  30  uses the baffle  36  to prevent the needle seat  20  from being separated from the adapter  30  through the rear end of the second shaft hole  33 , and the adapter  30  uses the inner flange  37  to prevent the needle seat  20  from being separated from the adapter  30  through the front end of the second shaft hole  33 . 
     As shown in  FIG.  2   , the injection barrel  40  has a barrel body  41 , a shaft portion  42  connected with the front end of the barrel body  41 , and a support portion  43  connected with the rear end of the barrel body  41 . A plurality of elongated ribs  44  (the number is unlimited) are provided at the outer surface of the rear end of the barrel body  41  and arranged in an equally-spaced manner relative to the axial direction of the injection barrel  40 . As shown in  FIG.  1   , the shaft portion  42  of the injection barrel  40  is penetrated into the first shaft hole  22  of the needle seat  20  and the second shaft hole  33  of the adapter  30  through the rear end of the adapter  30 . 
     As shown in  FIG.  2   , the outer sleeve  50  has a front opening  51  and a rear opening  52 . The outer sleeve  50  has a first annular rib  53  adjacent to the front opening  51  and a second annular rib  54  adjacent to the rear opening  52 . As shown in  FIGS.  1  and  5   , the outer sleeve  50  is sleeved on the injection barrel  40  and movable along the axial direction of the injection barrel  40 . When the outer sleeve  50  is moved backwards to a position where the first annular rib  53  is abutted with the elastic wings  35  of the adapter  30 , the elastic wings  35  of the adapter  30  are deformed elastically for allowing the first annular rib  53  to pass through without being stopped. When the outer sleeve  50  is moved to a first position PI as shown in  FIG.  1   , the elastic wings  35  of the adapter  30  return to original status so as to be engaged with the first annular rib  53  of the outer sleeve  50 , such that the outer sleeve  50  is sleeved on the barrel body  41  of the injection barrel  40 , and the needle seat  20  and the needle  12  are allowed to protrude from the front opening  51  of the outer sleeve  50 , and further, the second annular rib  54  of the outer sleeve  50  are forced against the elongated ribs  44  of the injection barrel  40  for performing the positioning of the outer sleeve  50 . When the outer sleeve  50  is moved forwards to a position where the third annular rib  55  is abutted with the elastic wings  35  of the adapter  30 , the elastic wings  35  of the adapter  30  are deformed elastically for allowing the third annular rib  55  to pass through without being stopped. When the outer sleeve  50  is moved forwards to a second position P 2  as shown in  FIG.  5   , the outer sleeve  50  accommodates the needle seat  20 , the needle  12 , and the adapter  30  inside, and further, the elastic wings  35  of the adapter  30  are located between the second annular rib  54  and the third annular rib  55  for performing the positioning of the outer sleeve  50 . In addition, under the condition that the outer sleeve  50  is located at the second position P 2 , when the outer sleeve  50  is pushed continuously to move forwards, as shown in  FIG.  6   , the outer sleeve  50  pushes against the elastic wings  35  of the adapter  30  through the second annular rib  54  because the inner diameter of the second annular rib  54  is greater than the inner diameter of the first annular rib  53  and the inner diameter of the third annular rib  55 . As such, the outer sleeve  50  is detached from the injection barrel  40  together with the needle seat  20 , the needle  12 , and the adapter  30 . 
     It can be seen from the above that before drawing liquid medicine into the injection barrel  40 , a user pushes the outer sleeve  50  forwards to the second position P 2  as shown in  FIG.  5    for preventing others from being injured by the needle  12 . When drawing the liquid medicine, the user pulls the outer sleeve  20  backwards to the first position P 1  as shown in  FIG.  7    to expose the needle  12  to the outside. At this time, the user inserts the needle  12  into a medicine bottle, and then pulls the push rod  45  to draw the liquid medicine into the injection barrel  40 . After drawing of the liquid medicine, if it is unnecessary to inject the liquid medicine immediately, the user can push the outer sleeve  50  forwards to the second position P 2  as shown in  FIG.  5    for protecting the needle  12  from contamination; moreover, the user can draw the liquid medicine into several injection barrels  40  for subsequent use. When preparing to inject the liquid medicine, the user pulls the outer sleeve  50  backwards to the first position P 1 , and then pushes the push rod  54  to inject the liquid medicine through the needle  12 , as shown in  FIG.  8   . Therefore, the safety syringe  10  of the present invention is quite convenient to use. 
     In addition to be used with the needle  12 , the safety syringe  10  of the present invention can be used with a needle-free dosing connector  16 , As shown in  FIG.  9   , after drawing of the liquid medicine, the user pushes the outer sleeve  50  forwards to the second position P 2 , and then pushes the outer sleeve  50  continuously, such that the outer sleeve  50  is pushed against the elastic wings  35  of the adapter  30  through the second annular rib  54 . By this way, the outer sleeve  50  is detached from the injection barrel  40  together with the needle seat  20 , the needle  12 , and the adapter  30 . At this time, the shaft portion  42  of the injection barrel  40  is connected with the needle-free dosing connector  16 , as shown in  FIG.  10   , and then the push rod  45  is pushed to inject the liquid medicine into an infusion tube  18  through the needle-free dosing connector  16 . Since the needle  12  is detached in advance, the situation that the infusion tube  18  is punctured accidentally by the needle  12  can be avoided. 
     As indicated above, when the liquid medicine is drawn, the outer sleeve  50  is pulled to the first position P 1  to expose the needle  12  to the outside for facilitating drawing of the liquid medicine. After the liquid medicine is drawn, the liquid medicine can be injected by using the needle  12  or the needle-free dosing connector  16  according to actual needs for enhancing convenience of use. In other words, the safety syringe  10  of the present invention provides a separate design to enable the injection barrel  40  to be used with the needle  12  or the needle-free dosing connector  16  without the need for a new mold. This can reduce waste of material and lower manufacturing costs.