Disposable safety syringe

Abstract

The invention discloses a disposable safety syringe, which relates to the technical field of syringes, and comprises an empty cylinder, a push rod is arranged in the empty cylinder along the axial direction in a sliding manner, a piston attached to the inner wall of the empty cylinder is arranged at the end part of the push rod, and a nipple for connecting a needle is arranged at one end of the empty cylinder and is conical along the axial direction; an annular concave portion located in the middle is arranged on the inner wall of the nipple, an annular fixing piece is fixedly connected to the center of the end of the piston, a plugging piece is arranged in the annular fixing piece in a compressed mode, in the initial state, the plugging piece is stored in the annular fixing piece in the radial compression state, and the plugging piece is pushed to enter the annular concave portion after the piston abuts against the end of the hollow cylinder to be compressed. According to the disposable safety syringe, the movable plugging piece is arranged, and the plugging piece is pushed by the piston at the injection end stage of the syringe so as to enter the annular concave part and be unfolded, so that the interior of the nipple is plugged, the empty cylinder is prevented from being used for the second time, and the syringe is prevented from being reused.

Description

Technical Field

[0001] The invention relates to the technical field of syringes, in particular to a disposable safety syringe. Background Art

[0002] Syringes are the most commonly used medical tools in medical procedures. In order to avoid cross-infection of viruses caused by the use of unsanitary syringes, disposable syringes are mainly used in current medical activities. Therefore, many discarded disposable syringes are generated every year in countries with relatively high medical levels.

[0003] In order to prevent the discarded disposable syringe from being transferred to countries or regions with backward medical levels through simple processing, a locking structure or a destructive structure is usually set on the disposable syringe, such as setting an easy-to-break structure on the piston push rod. This is the most common and simple way, but there are two problems with this type of syringe after use. First, breaking the push rod requires medical staff to take the initiative to operate, and in actual operation, it is directly thrown into a specific medical waste bin after use. Second, breaking the push rod does not affect the use of the syringe and the piston, and only the push rod needs to be replaced. Therefore, in the case of interests, the used disposable syringe will still be used. For example, the syringe disclosed in CN113713214B uses two methods to distinguish between coloring and limiting the movement of the piston rod to prevent secondary use. Although it can work, this solution does not consider the cost and the risk of the pigment bag when the syringe is used normally, so it is difficult to promote and use on a large scale. To this end, we propose a disposable safety syringe. Summary of the invention

[0004] The object of the present invention is to provide a disposable safety syringe to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a disposable safety syringe, comprising an empty barrel, a push rod is arranged in the empty barrel for sliding along its axial direction, a piston is arranged at the end of the push rod and is in contact with the inner wall of the empty barrel, a nipple for connecting a needle is arranged at one end of the empty barrel, the nipple is tapered along its axial direction, the inner wall of the nipple is provided with an annular recess located in the middle, an annular fastener is fixedly connected to the center of the end of the piston, the annular fastener is fit to the inner wall of the nipple, the end of the annular fastener extends to the edge of the annular recess, a plugging piece is compressed and arranged in the annular fastener, the plugging piece is in the form of a shell protruding toward the nipple end, and a plurality of expansion joints are arranged at intervals at the radial edge of the plugging piece, in an initial state, the plugging piece is in a radially compressed state in the annular fastener, and the piston pushes the plugging piece into the annular recess after being compressed against the end of the empty barrel.

[0006] Preferably, the annular fastener is provided with a first extension portion on the end surface away from the piston and facing the nipple end. The first extension portion is hollow and closed, and the area adapted to the annular recess is made of a flexible material for convex transition.

[0007] Preferably, a rigid push rod is provided at the center of the end of the push rod, penetrating the piston and contacting the blocking member in the initial state.

[0008] Preferably, the annular fixture is provided with a second extension portion at the end surface close to the push rod, the second extension portion is trumpet-shaped, and the end portion is integrated with the piston, and the inner side wall of the second extension portion is not fitted and fixed to the piston.

[0009] Preferably, the outer edge of the second extension portion is further connected to a plurality of protrusions, and the bottom walls of the protrusions are not fitted and fixed to the piston.

[0010] Preferably, the protrusion is an asymmetric component.

[0011] Preferably, the edges of both sides of the protrusion are arc-shaped, and the distance between the arc lines on both sides decreases radially outward along the hollow cylinder.

[0012] Preferably, a limiting portion is provided between the end of the push rod away from the piston and the end of the empty cylinder, and the limiting portion limits excessive movement of the push rod.

[0013] Preferably, the limiting portion is in the shape of a hollow truncated cone formed by coupling the two ends of the fan ring end to end.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The present invention provides a movable blocking member, which is pushed by the piston at the end of the injection of the syringe, so as to enter the annular recess and expand, thereby blocking the inside of the nipple, preventing the empty barrel from being used twice, and thus preventing the syringe from being reused;

[0016] The present invention provides a first extension portion extending into the nipple and in a closed shape, so that when the piston pushes the liquid medicine to inject, the remaining liquid medicine in the nipple can be injected, thereby reducing the residual amount of the liquid medicine;

[0017] The first extension portion of the present invention restricts the piston, so that the piston cannot be reused, which makes most of the available value of the syringe unable to be reused, thereby effectively avoiding the situation of repeated use, thereby avoiding health problems such as cross infection;

[0018] The second extension part and the protrusion provided in the present invention will cause the piston surface to be damaged when the piston is forcibly pulled out, thereby losing its practical value and avoiding secondary processing and use;

[0019] The arrangement of the invention is relatively simple, the increase in relative production cost is extremely small, and it is conducive to large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall cross-sectional structure of an existing disposable syringe;

[0021] Figure 2 It is a schematic diagram of the overall cross-sectional structure of the present invention;

[0022] Figure 3 for Figure 2 A schematic diagram of the structure of the middle A area;

[0023] Figure 4 It is a schematic diagram of the half-section structure of the plugging member in two states;

[0024] Figure 5 Schematic diagram of the top view of the blocking member in two states;

[0025] Figure 6 It is a schematic diagram of a half-section structure of the annular fastener, the first extension part and the second extension part;

[0026] Figure 7 is a schematic diagram of the structure between the second extension portion and the protrusion and the piston;

[0027] Figure 8 is a schematic diagram of the pulling state between the second extension portion and the piston surface;

[0028] Fig. 9 A schematic diagram of an implementation structure of the restriction part.

[0029] In the figure: 1-empty cylinder; 2-push rod; 3-piston; 4-nipple; 5-annular recess; 6-annular fastener; 7-sealing piece; 8-expansion joint; 9-thrust rod; 10-restricting portion; 61-first extension portion; 62-second extension portion; 621-protrusion. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6The present invention provides a technical solution: a disposable safety syringe, comprising an empty barrel 1, the empty barrel 1 is a straight cylindrical structure with one end open, the other end opposite to the open end is connected to a nipple 4, the nipple 4 is hollow cone-shaped, and is used to connect a needle, and a finger hook is also integrated at the open end of the empty barrel 1;

[0032] The piston 3 is detachably mounted at one end of the push rod 2. Generally, a columnar bolt is arranged at the end of the push rod 2. The columnar bolt is provided with partitions at intervals along the axial direction, and a groove is adapted to be provided at the bottom of the piston 3. The end of the push rod 2 away from the piston 3 is integrally connected to a push handle. The push rod 2 is pushed through the push handle, and the other two fingers are placed on the finger hooks to achieve injection. The above are all conventional parts of existing disposable syringes;

[0033] In this solution, an annular recess 5 is provided on the inner wall of the nipple 4 in the prior art, and the annular recess 5 is located in the middle position, that is, the two edge lines of the annular recess 5 along the axial direction of the hollow cylinder 1 do not overlap with the edge lines at both ends of the inner wall of the nipple 4, and further, the annular recess 5 is radially outward from the axis of the hollow cylinder 1, and the edge lines of its cross section tend to face each other at both ends in the axial direction of the hollow cylinder 1, that is, the annular recess 5 will not produce a situation in which the inner part is small and the outer part is large in the radial direction, which increases the difficulty of production. The annular fastener 6 is solid, that is, non-flexible, and its outer side wall is adapted to the inner wall of the nipple 4. Its main function is to stabilize the plugging member 7 in the initial state;

[0034] The blocking member 7 is a disc-shaped shell protruding to one side, and a radial expansion joint 8 is provided at the edge. Figure 4 and Figure 5 As shown, the initial state is a compressed state, that is, Figure 4 The one with a larger arc at the bottom corresponds to Figure 5 In the right side of the figure, in the compressed state, the outer edge of the blocking member 7 is restricted by the inner wall of the annular fixture 6 and moves with the annular fixture 6. After expansion, Figure 4 The smaller arc in the middle and upper part corresponds to Figure 5 On the left side, the expanded blocking member 7 will enter the annular recess 5. Since the inner wall of the nipple 4 is tapered, it cannot be pushed out in the injection direction. In the opposite direction, it is opposite to the bending direction of the blocking member 7, so it cannot be compressed and thus cannot be detached.

[0035] Specifically, when in use, in the initial state, the piston 3 is in contact with the inner wall of the end of the empty cylinder 1. In this state, the blocking member 7 is compressed in the annular fastener 6 and is in a critical state. It only needs to apply external force in the axial direction to enter the annular recess 5 and expand. This initial state is the factory setting state. When used by medical staff, they will first insert the needle, and then insert the needle into a medicine bottle or other liquid carrier, pull the push rod 2 to generate negative pressure to absorb the liquid medicine, and inject after the liquid medicine is absorbed. When injecting, push the push rod 2, and when the end face of the piston 3 contacts the inner bottom wall of the empty cylinder 1, that is, At this time, the injection is completed. Because the push rod 2 is directly pushed without limit during extrusion, the piston 3 will be compressed when it contacts the inner bottom wall of the empty cylinder 1, and the corresponding part of the piston 3 located within the range of the annular fixture 6 is not restricted, and will move forward a little, thereby pushing the blocking member 7 out of the annular fixture 6. The annular fixture 6 itself is restricted by the tapered inner wall of the nipple 4 and will not move. After the blocking member 7 enters the annular recess 5 from the annular fixture 6, it will automatically expand and block because there is no restriction on the side, that is, the empty cylinder 1 cannot be used a second time.

[0036] Due to the structure of the plugging member 7 itself, it is difficult to be pushed out from both ends of the nipple 4. If it is violently destroyed, the empty cylinder 1 is easily damaged. In addition, because the plugging member 7 is in an active state in the annular recess 5, it is difficult to remove the plugging member 7 using a rotating drill bit. Therefore, it is difficult to use it a second time after one use. Even if it can be used after processing, it will lose its processing value because the processing cost is too high and no benefits are generated.

[0037] See also Figure 3 and Figure 6 The first extension portion 61 is an inverted cup-shaped structure as a whole, and the outer wall is adapted to the inner wall of the nipple 4. The first extension portion 61 is divided into two parts, one part adopts a flexible structure and protrudes radially outward so as to adapt to the annular recess 5 and can be compressed before entering the annular recess 5, and the other part completely fits the inner wall of the nipple 4. This part can adopt a rubber structure such as the piston 3 or a solidified plastic structure. Its sealing state not only isolates the blocking member 7 from the internal environment of the empty cylinder 1, thereby preventing the drug liquid from affecting the drug liquid, but also can realize the function of cleaning the residual drug liquid in the nipple 4, because in the traditional one-time injection, the drug liquid in the nipple 4 cannot be used to inject into the patient's body, and the first extension portion 61 can play this role;

[0038] See also Figure 3In this embodiment where only the annular fastener 6 is provided, the push rod 9 is coaxially provided at the end of the push rod 2, and one end of the push rod 9 contacts the blocking member 7, and the side wall of the push rod 9 is wrapped by the piston 3 and can slide. The purpose of providing the push rod 9 is to facilitate and better push the blocking member 7, because when the push rod 9 is not provided, the relative movement of the piston 3 within the inner range of the annular fastener 6 is very small, and there may be a possibility that the blocking member 7 cannot be completely pushed out. Therefore, providing the push rod 9 can completely avoid this situation and better push the blocking member 7;

[0039] Compared with the previous embodiment, when the first extension portion 61 is provided, a avoidance is directly opened at the center of the end of the piston 3 to avoid friction. One end of the push rod 9 is connected to the push rod 2, and the other end abuts against the blocking member 7. After the first extension portion 61 is provided, the limit of the blocking member 7 will also restrict the piston 3 and cannot be pulled back to its original position for reuse, otherwise the first extension portion 61 or the piston 3 will be damaged.

[0040] See also Figure 3 , Figure 6 and Figure 8 The second extension part 62 is connected to the lower end of the annular fixture 6. The second extension part 62 is preferably made of the same material as the piston 3 and is integrated. That is, the second extension part 62 can be regarded as a part of the top surface of the piston 3, but one end of the second extension part 62 is in an active state. The effect of this method is that when the syringe is reprocessed, if the push rod 2 is pulled or the piston 3 is pulled by other tools, then Figure 8 In the state shown, the second extension portion 62 will be pulled, and the piston 3 will move downward, and the two will produce relative movement. The pulling of the second extension portion 62 can tear the integrity of the upper surface of the piston 3, and because of the uncertainty of the breakage, it can affect its overall sealing, thereby indirectly causing the piston 3 to lose its secondary use value.

[0041] See also Figure 7 and Figure 8 , relative to the second extension portion 62 with a complete edge, it may also break when being pulled without damaging the surface of the piston 3, so Figure 7 The protrusion 621 is arranged in a relatively irregular state and extends to more areas of the surface of the piston 3. Figure 8 In the pulling state, the destructiveness of the protrusion 621 is greater than that of the second extension portion 62, and is more destructive to the surface of the piston 3;

[0042] Furthermore, when the asymmetric protrusion 621 is pulled, the force is not relatively balanced, so it is easy to concentrate the force, thereby better tearing the surface of the piston 3;

[0043] Furthermore, the edges of both sides of the protrusion 621 are arc-shaped, and the spacing between the arcs on both sides decreases radially outward along the empty cylinder 1, that is, the two edges are first spirally oriented in the same direction, and the surface of the piston 3 decreases in size radially outward. This arrangement allows the protrusion 621 to produce strip-shaped cracks on the surface of the piston 3 when it is pulled, and because of the spiral shape, it is easier to tear open.

[0044] In order to prevent the piston 3 or the push rod 9 from pushing out the blocking member 7 prematurely due to collision during production, packaging and transportation, a limiting portion 10 is provided to limit the axial advancement of the push rod 2.

[0045] As one of the embodiments, the limiting portion 10 is an annular conical structure that is a fan-ring structure in the expanded state, and its end face can be C-shaped. It is clamped on the push rod 2 through its toughness to limit the axial movement of the push rod 2, and can also be connected end to end, with the connection part snapped or glued, and an easy-tear notch is set at one end of the outer side.

[0046] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0047] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A disposable safety syringe, comprising an empty barrel (1), a push rod (2) being slidably arranged in the empty barrel (1) along its axial direction, a piston (3) being arranged at the end of the push rod (2) and being in contact with the inner wall of the empty barrel (1), a nipple (4) for connecting a needle being arranged at one end of the empty barrel (1), the nipple (4) being tapered along its axial direction, characterized in that: The inner wall of the nipple (4) is provided with an annular recess (5) located in the middle. The center of the end of the piston (3) is fixedly connected with an annular fixture (6). The annular fixture (6) fits the inner wall of the nipple (4). The end of the annular fixture (6) extends to the edge of the annular recess (5). A sealing member (7) is compressed and arranged in the annular fixture (6). The sealing member (7) is a shell-shaped body protruding toward the end of the nipple (4). A plurality of expansion joints (8) are provided at intervals at the radial edge of the sealing member (7). In an initial state, the sealing member (7) is in a radially compressed state in the annular fixture (6). After the piston (3) is compressed by contacting the end of the empty cylinder (1), the sealing member (7) is pushed into the annular recess (5).

2. A disposable safety syringe according to claim 1, characterized in that: The annular fastener (6) is provided with a first extension portion (61) at the end of the end facing the nipple (4) away from the piston (3); the first extension portion (61) is hollow and closed, and the area adapted to the annular recess (5) is made of a flexible material with an outward convex transition.

3. A disposable safety syringe according to claim 1 or 2, characterized in that: A rigid push rod (9) is provided at the center of the end of the push rod (2) and penetrates the piston (3) to contact the blocking member (7) in the initial state.

4. A disposable safety syringe according to claim 2, characterized in that: The annular fixture (6) is provided with a second extension portion (62) on the end surface close to the push rod (2); the second extension portion (62) is trumpet-shaped, and the end portion is integrally arranged with the piston (3); the inner side wall of the second extension portion (62) is not fitted and fixed to the piston (3).

5. A disposable safety syringe according to claim 4, characterized in that: The outer edge of the second extension portion (62) is also connected to a plurality of protrusions (621), and the bottom walls of the protrusions (621) are not fitted and fixed to the piston (3).

6. A disposable safety syringe according to claim 5, characterized in that: The protrusion (621) is an asymmetric component.

7. A disposable safety syringe according to claim 6, characterized in that: The edges on both sides of the protrusion (621) are arc-shaped, and the distance between the arc lines on both sides decreases radially outwards along the hollow cylinder (1).

8. A disposable safety syringe according to claim 1 or 2, characterized in that: A limiting portion (10) is provided between the end of the push rod (2) away from the piston (3) and the end of the empty cylinder (1), and the limiting portion (10) limits excessive movement of the push rod (2).

9. A disposable safety syringe according to claim 8, characterized in that: The limiting portion (10) is in the shape of a hollow truncated cone formed by coupling the two ends of the fan ring end to end.

Images