Needle protection type prefilled syringe, component, and method for installing the component

Abstract

The present invention belongs to the technical field of pre-filled syringes, and particularly relates to a pre-filled syringe with a needle protection, components, and an installation method of the components. The present invention achieves the technical effect of effectively covering the needle conveniently after injection through a protective cover unit of a needle mounting member sleeved on an injection barrel and an elastic hook unit for fixing the protective cover unit. The present invention has the following advantages: First, during use, only by sliding the protective cover along the injection barrel, the operations of opening for injection and closing for discarding can be realized; Second, an elastic hook is provided to hook with the side of the sliding opening for fixing the protective cover; Third, a stop surface is provided on the elastic plate, which is engaged with the elastic hook to fix the protective cover in an open state; Fourth, by pinching the elastic plate, the protective cover can be ejected towards the needle to achieve closing, and it can be operated with one hand; Fifth, when the needle protective cover covers the injection needle, the elastic plate and the elastic hook are disengaged, which is convenient for opening the protective cover and directly performing injection.

Description

Technical Field

[0001] The present invention belongs to the technical field of pre-filled syringes, and particularly relates to a pre-filled syringe with a needle protection, components, and an installation method of the components. Background Art

[0002] A syringe is a common medical tool, mainly used to draw or inject gas or liquid with a needle. This process is called injection. A syringe consists of a barrel with a small hole at the front end and a piston core rod that matches it, and is used to inject a small amount of liquid or gas into areas that cannot be reached by other methods. When the core rod is pushed in, the liquid or gas is extruded. However, a disposable syringe has poor stability. It needs to be filled with medicine before use, and it is very inconvenient to expel air after filling. Therefore, a pre-filled syringe that is pre-filled with medicine and can be directly injected after opening has been developed and widely used. Nowadays, it is widely used in vaccination during the COVID-19 pandemic and shows high market value.

[0003] However, existing pre-filled syringes are often discarded casually after use, with the needles exposed, which is very dangerous. To solve the problem of needle exposure after syringe disposal, nurses often reinstall the removed needle protection cover. But this has many drawbacks. On the one hand, the needle protection cover is customized for the needle and has a small opening, making it very difficult to reinstall after being removed. On the other hand, the process of reinstalling is likely to let the needle prick the nurse's hand, causing infection to medical staff and further facilitating the spread of the epidemic.

[0004] Therefore, in summary, there is an urgent need for a pre-filled syringe that can conveniently and effectively cover the needle after injection to avoid needle injury. Summary of the Invention

[0005] The object of the present invention is to provide a pre-filled syringe with a needle protection, components, and an installation method of the components. The present invention achieves the technical effect of conveniently and effectively covering the needle after injection through a protective cover unit of a needle installation part sleeved on an injection barrel and an elastic hook unit for fixing the protective cover unit.

[0006] The technical solution adopted by the present invention to solve the above problems is: a pre-filled syringe with a needle protection, including an injection barrel, a needle installation part, an injection needle, and a needle protection cover; wherein:

[0007] The needle installation part is arranged at the distal end of the injection barrel. The needle installation part has a through hole that communicates with the inside of the injection barrel. The injection needle is installed on the needle installation part in a way of inserting into the through hole. The needle protection cover is sleeved on the needle installation part and completely covers the injection needle. The injection barrel, the needle installation part, the injection needle, and the needle protection cover have a common axis;

[0008] It further includes a protective cover unit, and the protective cover unit includes:

[0009] A protective cover provided with a sliding opening thereon to shield the injection needle;

[0010] It further includes an elastic hook unit, and the elastic hook unit includes an elastic hook disposed in the sliding opening.

[0011] The protective cover unit further includes an elastic plate, the elastic plate is cantilevered in the sliding opening, and the proximal end has a tendency to retract radially inward along the protective cover.

[0012] The proximal end of the elastic plate has a proximal end stop surface for jacking up the elastic hook when the protective cover is closed, thereby locking the protective cover.

[0013] A distal end stop surface is provided on the inner side of the elastic plate for jacking up the elastic hook when the protective cover is opened, thereby locking the protective cover.

[0014] The elastic hook includes a radial plate, and a closing stop surface is provided on the distal side of the radial plate for jacking up the proximal end stop surface.

[0015] The elastic hook further includes an axial plate, and an opening stop surface is provided on the proximal side of the axial plate for jacking up the distal end stop surface.

[0016] The proximal end of the axial plate expands radially outward along the protective cover. When jacking up the distal end stop surface, by pressing or pulling the elastic plate radially inward or outward along the protective cover, the opening stop surface of the axial plate is disengaged from the jacking state with the distal end stop surface.

[0017] A raised block is provided on the inner side surface of the proximal end side of the elastic plate. When the needle protection sleeve is sleeved on the needle mounting member, the raised block is jacked up radially outward along the protective cover, so that the proximal end stop surface on the elastic plate is disengaged from the jacking state with the closing stop surface on the radial plate.

[0018] The proximal side of the raised block has an opening guiding surface for jacking up the axial plate of the elastic hook when the protective cover slides proximally, so that the elastic hook can cross over the raised block.

[0019] The raised block further includes a closing guiding surface for jacking up the axial plate of the elastic hook when the protective cover slides distally, so that the elastic hook can cross over the raised block.

[0020] The protective cover unit further includes an expansion groove provided at the proximal end of the protective cover for the proximal expansion of the protective cover.

[0021] The protective cover unit further includes a guiding inclined surface provided at the proximal end of the protective cover for jacking up the axial plate of the elastic hook.

[0022] A component of the needle-protected prefilled syringe, comprising a push rod and a piston; wherein:

[0023] The push rod is disposed on the piston;

[0024] The piston is installed in the injection barrel, and when pushing the push rod in the distal direction, it is used to push the liquid medicine out through the injection needle.

[0025] An installation method of a component of a needle-protected prefilled syringe, comprising the following steps:

[0026] S1. Axially insert the needle protection sleeve into the protective cover;

[0027] S2. Axially sleeved the protective cover with the needle protection sleeve on the needle mounting member;

[0028] S3. Push the piston into the injection barrel;

[0029] S4. Dispose the push rod on the piston.

[0030] A usage method of a component of a needle-protected prefilled syringe, comprising the following steps:

[0031] S1. Axially move the protective cover in the proximal direction of the injection barrel until the back side of the elastic hook abuts against the distal side of the sliding opening, thereby exposing the needle protection sleeve;

[0032] S2. Open the needle protection sleeve to expose the injection needle;

[0033] S3. Perform an injection operation;

[0034] S4. After the injection operation is completed, axially move the protective cover in the distal direction of the injection barrel until one side of the elastic hook hooks the proximal side of the sliding opening, thereby completely covering the injection needle.

[0035] The present invention has the following advantages:

[0036] First, it is convenient to install, has a simple structure, and during use, only need to slide the protective cover along the injection barrel to achieve the operations of opening for injection and closing for discarding;

[0037] Second, an elastic hook is provided to hook together with the side of the sliding opening for fixing the protective cover, with good fixing effect and the protective cover is not easily disengaged from the engaged state;

[0038] Third, an elastic plate is provided, and the elastic plate has a stop surface, which is engaged with the elastic hook to fix the protective cover in an open state, facilitating nurses to perform injections;

[0039] Fourth, after the nurse finishes the injection, by pinching the elastic plate with two fingers, the stopping surface and the elastic hook can be disengaged, so that the protective cover is ejected towards the needle to achieve closing. For nurses with relatively short fingers, the closing operation can also be achieved with one hand;

[0040] Fifth, when the needle protective cover covers the injection needle, the elastic plate and the elastic hook are in a disengaged state, which facilitates the nurse to open the protective cover directly for injection. Description of the Drawings

[0041] Figure 1 It is a schematic structural diagram of the needle protective cover of the present invention covering the injection needle, with a protective cover unit and an elastic hook unit installed on the injection syringe barrel.

[0042] Figure 2 It is a schematic structural diagram of the needle protective cover of the present invention covering the injection needle, with an elastic hook unit installed on the injection syringe barrel.

[0043] Figure 3 It is a schematic structural diagram of the elastic hook unit installed on the injection syringe barrel of the present invention.

[0044] Figure 4 It is a schematic structural diagram of the protective cover unit and the elastic hook unit installed on the injection syringe barrel of the present invention.

[0045] Figure 5 It is a schematic explosion diagram of a pre-filled syringe of the present invention.

[0046] Figure 6 It is Figure 4 a schematic cross-sectional structural diagram along line A-A in

[0047] Figure 7 It is Figure 6 a schematic enlarged structural diagram of the elastic hook.

[0048] Figure 8 It is Figure 6 a schematic enlarged structural diagram of the injection needle.

[0049] Figure 9 It is a schematic structural diagram of the elastic hook of the present invention.

[0050] Figure 10 It is a schematic structural diagram of the other perspective of the elastic hook of the present invention.

[0051] Figure 11 It is a schematic structural diagram of the protective cover unit of the present invention.

[0052] Figure 12 It is a schematic structural diagram of the other perspective of the protective cover unit of the present invention.

[0053] Figure 13This is a schematic structural diagram of the elastic plate in the present invention.

[0054] In the drawings, the components represented by the reference numerals are as follows: protective cover unit 1, elastic hook unit 2, syringe barrel 11, needle mounting member 12, injection needle 13, needle protective sleeve 14, protective cover 101, sliding opening 102, elastic plate 103, expansion groove 104, guiding inclined surface 105, elastic hook 202, proximal stop surface 103a, distal stop surface 103b, raised block 103c, opening guiding surface 103d, closing guiding surface 103e, stop groove 201a, radial plate 202a, axial plate 202b, closing stop surface 202c, opening stop surface 202d, through hole 12a. Detailed implementation mode

[0055] Definition

[0056] 1. Distal end: refers to the end far from the drug injection port of the syringe barrel.

[0057] 2. Proximal end: refers to the end facing the drug injection port of the syringe barrel.

[0058] 3. Axis: refers to the vertical line passing through the center of a cross-section of an object with a circular cross-section.

[0059] 4. Open: refers to the state of exposing the syringe needle or the syringe needle and the protective sleeve.

[0060] 5. Close: refers to the state of covering the syringe needle or the syringe needle and the protective sleeve.

[0061] 6. Set: refers to all ways such as bonding, snapping, welding, screwing, placing, etc. for arranging and combining two components together.

[0062] 7. Lift: refers to the situation where component one acts on component two with a force, causing component two to move or deform in a direction opposite to the position of component one.

[0063] The following is only a preferred embodiment of the present invention, and does not limit the scope of the present invention.

[0064] Embodiment: As shown in the attached Figure 1-13 figure, a needle-protected prefilled syringe includes a syringe barrel 11, a needle mounting member 12, an injection needle 13 and a needle protective sleeve 14; wherein:

[0065] The needle mounting member 12 is provided at the distal end of the injection syringe barrel 11. The needle mounting member 12 has a through hole 12a that communicates with the inside of the injection syringe barrel 11. The injection needle 13 is mounted on the needle mounting member 12 in a manner of inserting into the through hole 12a. The needle protection sleeve 14 is sleeved on the needle mounting member 12 and completely covers the injection needle 13. The injection syringe barrel 11, the needle mounting member 12, the injection needle 13, and the needle protection sleeve 14 have a common axis;

[0066] It further includes a protective cover unit 1. The protective cover unit 1 includes:

[0067] A protective cover 101 provided with a sliding opening 102 thereon to shield the injection needle 13;

[0068] It further includes an elastic hook unit 2. The elastic hook unit 2 includes an elastic hook 202 disposed in the sliding opening 102.

[0069] In this embodiment, the injection syringe barrel 11, the needle mounting member 12, the injection needle 13, and the needle protection sleeve 14 are all essential components of a syringe in the prior art to achieve the functions of filling and injecting drugs. The installation methods of the elastic hook unit 2 and the protective cover unit 1 are as follows:

[0070] 1. The elastic hook unit 2 is mounted on the needle mounting member 12, and the bending direction of the hook faces the proximal end of the injection syringe barrel 11;

[0071] 2. When the protective cover 101 of the protective cover unit 1 is sleeved and mounted on the needle mounting member 12, it is sleeved on the elastic hook 202 of the elastic hook unit 2 through a deformation effect. After passing over the elastic hook 202, the sliding opening 102 is sleeved on the elastic hook 202.

[0072] During the sleeving process, the elastic hook 202 slides into the sliding opening 102 and hooks the proximal side surface of the sliding opening 102, achieving the blocking effect on the sliding of the protective cover 101 in the distal direction.

[0073] After the installation is completed, the above components are transferred to the downstream manufacturer for drug filling. The drug is filled from the drug injection port of the injection syringe barrel 11, and then a push rod and an injection piston are installed on the injection syringe barrel 11 through the drug injection port to complete the pre-filled and sealed syringe.

[0074] In addition, it should be noted that the needle protection sleeve 14 uses the existing pre-filled and sealed needle sheath material and shape, which has been standardized in production, rather than a non-standard special-shaped cap. The advantages are as follows:

[0075] 1. It does not change the user's usage habits;

[0076] 2. There is no need to re-evaluate the chemical compatibility of the rubber cap, greatly reducing the project development cycle and product registration cycle;

[0077] 3. Enhance customer confidence.

[0078] The usage method of the pre-filled syringe is as follows:

[0079] 1. Axially move the protective cover 101 along the proximal direction of the injection barrel 11 until the back side of the hook of the elastic hook 202 abuts against the distal side of the sliding port 102, thereby exposing the needle protection sleeve 14;

[0080] 2. Open the needle protection sleeve 14 to expose the injection needle 13;

[0081] 3. Perform the injection operation;

[0082] 4. After the injection operation is completed, axially move the protective cover 101 along the distal direction of the injection barrel 11 until the hook side of the elastic hook 202 hooks the proximal side of the sliding port 102, thereby completely covering the injection needle 13.

[0083] The installation method of the pre-filled syringe is as follows:

[0084] S1. Axially install the needle protection sleeve 14 into the protective cover 101;

[0085] S2. Axially sleeved the protective cover 101 with the needle protection sleeve 14 on the needle mounting member 12;

[0086] S3. Push the piston into the injection barrel 11;

[0087] S4. Set the push rod on the piston.

[0088] In this embodiment, the needle protection sleeve 14 is first installed in the protective cover 101, which is beneficial to the steps of automatic assembly of the syringe assembly, can simplify the production line process, reduce the cost of component installation, and further improve the market competitiveness.

[0089] It should be noted that the position where the elastic hook 202 is set can be a part of the injection barrel 11, or a part of the needle mounting member 12, or a part between the injection barrel 11 and the needle mounting member 12.

[0090] In addition, the syringe will be subjected to a light inspection when it leaves the factory. The "light inspection" is to check whether the filling and stoppering of the syringe are qualified through manual observation through the syringe. Most of the integrated protective covers on the market will affect this process. For example, the Chinese Utility Model with announcement number CN214911888U and announcement date 2021-11-30 discloses a syringe needle protection device and a safety syringe thereof, including a protective outer sleeve, an installation inner sleeve, and a spring. This inner and outer sleeve connection method blocks the field of view inside the syringe and affects the light inspection process. In this embodiment, the protective cover unit 2 only covers the needle mounting tube 12 and part of the distal end of the syringe 11 when the syringe is not in use, which will not affect the light inspection process.

[0091] However, the protective cover 101 needs to achieve a fixing effect after being closed. Furthermore, the protective cover unit 1 further includes an elastic plate 103 . The elastic plate 103 is cantilevered and arranged in the sliding opening 102 , and the proximal end has a tendency to be retracted radially along the protective cover 101 .

[0092] The functions and implementation methods of the elastic plate 103 are as follows:

[0093] 1. When the protective cover 101 is opened, the elastic hook 202 pushes up the elastic plate 103 radially outward along the protective cover 101, so that the elastic plate 103 accumulates elastic potential energy. When the protective cover 101 is released, the elastic potential energy of the elastic plate 103 is released, driving the protective cover 101 to be ejected axially along the distal end direction of the injection syringe 11, thereby achieving an automatic closing effect;

[0094] 2. When the protective cover 101 is closed, the proximal end surface of the elastic plate 103 lifts up the back side of the curved hook of the elastic hook 202. In this way, when the protective cover 101 moves toward the proximal end, it is supported by the back side of the curved hook of the elastic hook 202. When it moves toward the distal end, it is hooked by the elastic hook 202 on the inner side surface of the sliding opening 102, thereby achieving a locking effect.

[0095] In order to make the elastic plate 103 lock the elastic hook 202 more firmly, further, the proximal end of the elastic plate 103 has a proximal stop surface 103 a for lifting the elastic hook 202 when the protective cover 101 is closed, thereby locking the protective cover 101 .

[0096] When the protective cover 101 is opened, the nurse still needs to pull it by hand, which is very inconvenient for the injection process. Furthermore, a distal stop surface 103b is provided on the inner side of the elastic plate 103, which is used to lift the elastic hook 202 when the protective cover 101 is opened, thereby locking the protective cover 101.

[0097] When the elastic hook 202 pushes the elastic plate 103 radially outward along the protective cover 101, according to the principle of interaction of forces, the elastic plate 103 also pushes the elastic hook 202 radially inward along the protective cover 101, causing the elastic hook 202 to contract. When passing over the distal end stop surface 103b, the elastic hook 202 rebounds and returns to its original shape, thus hooking the distal end stop surface 103b, so that the protective cover 101 cannot slide in the distal direction even under the pushing action of the elastic plate 103.

[0098] In addition, when the elastic hook 202 hooks the distal end stop surface 103b, a "pop" sound will be emitted to remind the nurse that the protective cover 101 has been locked and injection can be carried out.

[0099] In order to cooperate with the proximal end stop surface 103a, further, the elastic hook 202 includes a radial plate 202a, and a closing stop surface 202c is provided on the distal side of the radial plate 202a for pushing up the proximal end stop surface 103a.

[0100] When the closing stop surface 202c pushes up the proximal end stop surface 103a, a "pop" sound will also be emitted to remind the nurse that the protective cover 101 has been locked and can be discarded.

[0101] At the same time, in order to cooperate with the distal end stop surface 103b, further, the elastic hook 202 further includes an axial plate 202b, and an opening stop surface 202d is provided on the proximal side of the axial plate 202b for pushing up the distal end stop surface 103b.

[0102] After the injection is completed, it is necessary to close the protective cover 101. In order to make the closing process smoother, further, when the proximal end of the axial plate 202b expands radially outward along the protective cover 101 and pushes up the distal end stop surface 103b, by pressing the elastic plate 103 radially inward or pulling it radially outward along the protective cover 101, the opening stop surface 202d of the axial plate 202b is disengaged from the state of pushing up the distal end stop surface 103b.

[0103] When pulling the elastic plate 103 radially outward, the distal end stop surface 103b moves radially outward, so as to be disengaged from the state of being pushed up by the opening stop surface 202d of the axial plate 202b.

[0104] The principle of disengaging the opening stop surface 202d of the axial plate 202b from the state of pushing up the distal end stop surface 103b when pressing the elastic plate 103 radially inward is as follows:

[0105] When the elastic plate 103 is expanded under force, the proximal end expands more than the distal end. The inner surface of the elastic plate 103 is inclined outward from the distal end to the proximal end. The axial plate 202b is inclined in the same way as the inner surface of the elastic plate 103. When pressing the elastic plate 103 radially inward along the protective cover 101, because the elastic plate 103 is longer and the axial plate 202b is shorter, when squeezing the same distance, the axial plate 202b shrinks more significantly. So when squeezed to a certain extent, the opening stop surface 202d of the axial plate 202b disengages from the distal stop surface 103b, and the protective cover 101 is closed under the pushing action of the elastic plate 103.

[0106] The advantage of this design is that after the nurse finishes the injection, as long as using the thumb and index finger to gently pinch, the protective cover 101 can be closed. Compared with the way of pushing to close, this pinching way of closing does not require the nurse's palm to exert force, nor does it require moving the thumb and index finger away from the palm. For nurses with shorter fingers, single-handed operation can also be achieved, which is a very ingenious design. At the same time, the way of pinching inward is more convenient than dialing outward. There is no need to find an angle, nor to insert the nail into the sliding opening 102, and even no need for the nurse to observe with the naked eye to achieve the operation.

[0107] In order to make it unnecessary to specifically lift the elastic plate 103 when the protective cover 101 is opened, further, a raised block 103c is provided on the inner surface of the proximal side of the elastic plate 103. When the needle protection sleeve 14 is sleeved on the needle mounting member 12, the raised block 103c is pushed radially outward along the protective cover 101, so that the proximal stop surface 103a on the elastic plate 103 is disengaged from the closing stop surface 202c on the radial plate 202a.

[0108] In order to make the raised block 103c not affect the opening process of the protective cover 101, further, the proximal side of the raised block 103c has an opening guiding surface 103d, which is used to push up the axial plate 202b of the elastic hook 202 when the protective cover 101 slides proximally, so that the elastic hook 202 can cross over the raised block 103c.

[0109] In order to make the raised block 103c not affect the closing process of the protective cover 101, further, the raised block 103c also includes a closing guiding surface 103e, which is used to push up the axial plate 202b of the elastic hook 202 when the protective cover 101 slides distally, so that the elastic hook 202 can cross over the raised block 103c.

[0110] When the protective cover 101 is sleeved and installed on the needle mounting member 12, it is sleeved on the elastic hook 202 simultaneously through the deformation effect. However, since the protective cover 101 has a certain thickness and is difficult to deform, the installation is rather strenuous. Further, the protective cover unit 1 further includes an expansion groove 104 provided at the proximal end of the protective cover 101 for expanding the proximal end of the protective cover 101.

[0111] After the expansion groove 104 is provided, when the protective cover 101 deforms, the expansion space can be given to the protective cover 101 by the expansion of the expansion groove 104, making it easier to cross over the elastic hook 202.

[0112] In order to make the process of the protective cover 101 crossing over the elastic hook 202 smoother, further, the protective cover unit 1 further includes a guiding inclined surface 105 provided at the proximal end of the protective cover 101 for jacking up the axial plate 202b of the elastic hook 202.

[0113] The inclination angle of the guiding inclined surface 105 is similar to that of the axial plate 202b. When jacking up the axial plate 202b, the proximal end of the protective cover 101 is driven to expand, so as to cross over the elastic hook 202.

[0114] A component of the needle-protected prefilled syringe includes a push rod and a piston; wherein:

[0115] The push rod is arranged on the piston;

[0116] The piston is installed in the syringe barrel 11, and when pushing the push rod in the distal direction, it is used to push the liquid medicine out through the injection needle 13.

[0117] In this embodiment, the key lies in that the push rod and the piston are detachably connected together, so that the piston can be conveniently installed in the syringe barrel 11 in a mechanical automation manner. The assembly method of the push rod and the piston and the medicine filling method are as follows:

[0118] S1. Placing the syringe barrel: Grasp the syringe body and make the syringe barrel 11 perpendicular to the horizontal plane with the proximal opening facing upward;

[0119] In this embodiment, the "grasping" step generally uses a robotic arm with programmed design. The core of the program design is to make the syringe barrel 11 keep a vertical state when reaching the position to be filled, so that the liquid level after filling the medicine is perpendicular to the axis of the syringe barrel 11, so as to leave no air or leave less air after encapsulation without affecting the injection process.

[0120] S2. Filling the medicine: Fill the specified medicine into the syringe barrel 11;

[0121] In this embodiment, the "designated drug" refers to the drug filled according to the customer's needs. For example, for the manufacturer filling the COVID-19 vaccine, the designated drug is the inactivated novel coronavirus.

[0122] S3. Sleeve plugging: Insert the sleeve with the piston into the syringe barrel 11. There is a gap between the outer ring surface of the sleeve and the inner ring surface of the syringe barrel 11. Then use the sleeve push rod to push the piston along the inner ring surface of the sleeve into the syringe barrel 11.

[0123] In this embodiment, the piston is a common device for pushing the drug in the syringe, generally made of medical rubber, in a compressed state in the sleeve, and will expand to fit the inner side surface of the syringe barrel 11 after leaving the sleeve.

[0124] In addition, the sleeve is a slender steel pipe, inserted into the syringe barrel 11 from the crimped edge, and then use the sleeve push rod installed in the sleeve to send the piston to the designated position. The designated position means that after the piston leaves the sleeve, it can just be above the liquid level of the liquid medicine, with no air left or less air left but not affecting the injection process.

[0125] S4. Install the push rod: Insert the push rod into the syringe barrel 11 and install it on the piston to complete the filling and sealing process.

[0126] In this embodiment, there is an installation groove for installing the push rod at the proximal end of the piston. Use the robotic arm to rotate and insert the push rod into the installation groove.

[0127] S5. Conduct lamp inspection on the filled and sealed syringe, and label it, and finally complete the packaging.

[0128] The above has described the embodiments of the present invention in detail with reference to the drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various modifications can be made without departing from the purpose of the present invention. These are all non-creative modifications and are protected by the patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A needle protection type pre-filled syringe, comprising a syringe barrel (11), a needle mounting member (12), a syringe needle (13) and a needle protection sleeve (14); Wherein: The needle mounting member (12) is arranged at the distal end of the syringe barrel (11). The needle mounting member (12) has a through hole (12a) which is communicated with the inside of the syringe barrel (11). The syringe needle (13) is mounted on the needle mounting member (12) in a manner of inserting into the through hole (12a). The needle protection sleeve (14) is sleeved on the needle mounting member (12) and completely covers the syringe needle (13). The syringe barrel (11), the needle mounting member (12), the syringe needle (13) and the needle protection sleeve (14) have a common axis; It is characterized in that it further comprises a protective cover unit (1), and the protective cover unit (1) includes: A protective cover (101) provided with a sliding opening (102) thereon to shield the syringe needle (13); It further comprises an elastic hook unit (2), and the elastic hook unit (2) includes an elastic hook (202) extending into the sliding opening (102). The protective cover unit (1) further includes an elastic plate (103). The elastic plate (103) is cantilevered in the sliding opening (102) and has a tendency of inward contraction along the radial direction of the protective cover (101) at the proximal end. The proximal end of the elastic plate (103) has a proximal end stop surface (103a) for jacking up the elastic hook (202) when the protective cover (101) is closed, so as to lock the protective cover (101). A distal end stop surface (103b) is arranged on the inner side of the elastic plate (103) for jacking up the elastic hook (202) when the protective cover (101) is opened, so as to lock the protective cover (101); The protective cover unit (1) further includes an expansion groove (104) arranged at the proximal end of the protective cover (101) for the proximal end expansion of the protective cover (101).

2. A needle protection type pre-filled syringe according to claim 1, It is characterized in that, The elastic hook (202) includes a radial plate (202a), and a closing stop surface (202c) is arranged on the distal side of the radial plate (202a) for jacking up the proximal end stop surface (103a).

3. A needle protection type pre-filled syringe according to claim 2, It is characterized in that, The elastic hook (202) further includes an axial plate (202b), and an opening stop surface (202d) is arranged on the proximal side of the axial plate (202b) for jacking up the distal end stop surface (103b).

4. A needle protection type pre-filled syringe according to claim 3, It is characterized in that, When the proximal end of the axial plate (202b) expands radially outward along the protective cover (101) and jacks up the distal end stop surface (103b), by pressing or pulling the elastic plate (103) radially inward or outward along the protective cover (101), the opening stop surface (202d) of the axial plate (202b) is separated from the state of jacking up the distal end stop surface (103b).

5. A needle protection type prefilled syringe according to claim 2, wherein, a raised block (103c) is provided on the inner surface of the proximal side of the elastic plate (103). When the needle protection sleeve (14) is sleeved on the needle mounting member (12), the raised block (103c) is pushed radially outward along the protective cover (101), so that the proximal stop surface (103a) on the elastic plate (103) is disengaged from the closing stop surface (202c) on the radial plate (202a).

6. A needle protection type prefilled syringe according to claim 5, wherein, the proximal side of the raised block (103c) has an opening guiding surface (103d). When the protective cover (101) slides proximally, the axial plate (202b) for pushing up the elastic hook (202) is used, so that the elastic hook (202) can cross over the raised block (103c).

7. A needle protection type prefilled syringe according to claim 6, wherein, the raised block (103c) further includes a closing guiding surface (103e). When the protective cover (101) slides distally, the axial plate (202b) for pushing up the elastic hook (202) is used, so that the elastic hook (202) can cross over the raised block (103c).

8. A needle protection type prefilled syringe according to claim 3, wherein, the protective cover unit (1) further includes a guiding inclined surface (105) provided at the proximal end of the protective cover (101) for pushing up the axial plate (202b) of the elastic hook (202).

9. An assembly including the needle protection type prefilled syringe according to any one of claims 1 to 8, wherein, it includes a push rod and a piston; wherein: the push rod is provided on the piston; the piston is installed in the injection syringe barrel (11), and when pushing the push rod in the distal direction, it is used to push out the liquid medicine through the injection needle (13).

10. An installation method for the assembly of the needle protection type prefilled syringe according to claim 9, wherein, it includes the following steps: S1. Axially insert the needle protection sleeve (14) into the protective cover (101); S2. Axially sleeve the protective cover (101) with the needle protection sleeve (14) on the needle mounting member (12); S3. Push the piston into the injection syringe barrel (11); S4. Set the push rod on the piston.

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