Disposable sterile silicone-oil-free retractable self-destruction safety syringe

Abstract

The disposable sterile silicone-oil-free retractable self-destruction safety syringe is characterized in that the upper end of a needle head assembly is located in a cylinder cavity of a needle cylinder, a hanging buckle is formed on one side of the upper end of the needle head assembly, and an abutting arc surface is formed on the opposite side of the hanging buckle; a buckling inner hole capable of being matched with the hanging buckle is formed in the lower end of the sealing piston. When the buckling inner hole is matched with the hanging buckle, the sealing piston can drive the needle head assembly to move upwards, the needle head assembly is separated from the needle head cavity, the abutting arc face can gradually abut against the interior of the buckling inner hole, and the central axis of the needle head assembly and the central axis of the needle cylinder deflect. In the process, bubbles at the conical guide hole gradually move into the conical buckling hole along the conical guide hole under the pushing of the hanging buckle and the abutting arc face, in the injection process, the bubbles cannot be injected into the human body along with the needle head, and the injection safety is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of syringes, in particular to a disposable sterile silicone oil-free retractable self-destructive safety syringe. Background Art

[0002] The working principle of existing disposable self-destructing safety syringes (such as the one disclosed in patent number CN116966375A) is as follows: a push rod in the syringe pushes a sealing piston, which causes the sealing piston to squeeze the liquid medicine into the needle to achieve injection. Since the lower end of the sealing piston is provided with a snap-fit ​​structure that can cooperate with the tail end of the needle, the sealing piston and the needle are tightly fastened together after the injection is completed. When the push rod is pulled back, the sealing piston drags the needle to retract the needle into the syringe.

[0003] Although the structure of the self-destructive safety syringe effectively reduces the risk of needle exposure, it still poses a safety hazard in actual operation. Specifically, like ordinary syringes, a disposable self-destructive safety syringe needs to be aspirated before injection, that is, the push rod is pulled with the syringe, and the needle aspirates the liquid into the syringe barrel. After the aspiration is completed, the push rod is slightly pushed to expel the air in the needle before injection can be performed. However, since the lower end of the sealing piston of the self-destructive safety syringe is provided with a relatively complex inner hole structure for snapping the needle, a local geometric dead zone is formed, which causes tiny bubbles to easily gather (attach) around the inner hole, and conventional exhaust operations are difficult to completely drive away these trapped bubbles. Figure 6 As shown, after the injection, when the sealing piston 5 is squeezed to the lowest end of the syringe, the sealing piston 5 and the stepped surface 7 of the syringe inner cavity are in contact and closed (as shown at B). At this time, the bubbles accumulated around the inner hole will be squeezed into the needle channel under the action of the liquid medicine pressure (as shown at C), and injected into the patient's body through the needle along with the residual liquid medicine, posing a potential safety risk.

[0004] Furthermore, after the injection, the needle tip is contaminated with the patient's body fluids or tissue. Furthermore, the sharp tip makes it difficult to discard and dispose of, increasing the risk of infection or puncture for medical staff and cleaning personnel. There is also the risk of the syringe being re-circulated and reused. Furthermore, the barrel and piston of existing syringes are typically lubricated with silicone oil. During the injection process, this oil enters the body along with the injection solution, causing varying degrees of serious damage to tissue or blood. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a disposable sterile silicone oil-free retractable self-destructing safety syringe, which has the functional characteristics that the needle can retract and self-destruct after the injection is completed, and can prevent bubbles from being injected into the human body.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] A disposable, sterile, silicone-oil-free, retractable, self-destructive safety syringe comprises a syringe, a push rod disposed within the syringe, a sealing piston disposed at and connected to the lower end of the push rod, and a needle assembly mounted at the lower end of the syringe. The needle assembly is fixedly mounted within a needle cavity at the lower end of the syringe, and the upper end of the needle assembly is located within the syringe cavity of the syringe. A hook is formed on one side of the upper end of the needle assembly, and an abutting arc surface is formed on the opposite side of the hook. The lower end of the sealing piston is formed with a buckling inner hole that can cooperate with the hook.

[0008] The buckle inner hole comprises a straight hole, a tapered guide hole with a diameter gradually increasing from top to bottom is formed between the lower end of the straight hole and the lower bottom surface of the sealing piston, and a tapered buckle hole is formed at the upper end of the straight hole;

[0009] A syringe step surface is formed at the lower end of the syringe cavity. When the buckling inner hole and the hook are buckled together, the sealing piston moves down to the lowest end of the stroke, and a first slow flow gap is formed between the lower surface of the sealing piston and the syringe step surface.

[0010] A side-concave avoidance portion is formed below the hook. When the engaging inner hole and the hook are engaged with each other, the sealing piston moves down to the lowest end of the stroke, and a second slow-flow gap is formed between the avoidance portion and the inner side wall of the straight hole.

[0011] When the buckle inner hole is engaged with the hook, as the push rod is pulled, the sealing piston can drive the needle assembly to move upward, so that the needle assembly is disengaged from the needle cavity; the abutting arc surface can gradually abut against the side wall of the buckle inner hole, so that the central axis of the needle assembly and the central axis of the syringe are deviated;

[0012] The needle assembly includes a needle. When the needle assembly is pulled into the syringe cavity, the needle tip at the front end of the needle deviates and abuts against the inner wall of the syringe cavity.

[0013] The hook includes a guiding slope at the top and a barb located below the guiding slope. The conical buckle hole includes a conical inner hole that can cooperate with the guiding slope. A buckle step that can cooperate with the barb is formed between the conical inner hole and the straight hole.

[0014] The needle cavity includes a convex ring, an upper step surface is formed on the convex ring, a lower step surface is formed on the lower side of the convex ring, and an inverted conical inclined surface is formed below the lower step surface;

[0015] A first boss is provided below the same side of the hook, and the lower side of the first boss can abut against the upper step surface to limit the downward movement of the needle assembly; a second boss is provided below the same side of the abutting arc surface, and the second boss can abut against the lower step surface.

[0016] A needle channel communicating with the syringe cavity is provided in the needle assembly. The needle channel includes a first tapered channel and a first arc-shaped channel provided below the first tapered channel and having an arc-shaped sidewall.

[0017] A second curved channel is further provided below the curved channel, and a second tapered channel is further provided below the second curved channel;

[0018] The needle channel also includes a liquid channel connected to the upper side of the first tapered channel. The lower side of the liquid channel is used to install the needle of the syringe, and the upper end of the liquid channel is connected to the syringe cavity.

[0019] The side of the sealing piston is formed with a first sealing convex ring and a second sealing convex ring that can cooperate with the inner wall of the syringe. The lower edge line of the first sealing convex ring is connected to the lower bottom surface of the sealing piston, and the second sealing convex ring is arranged above the first sealing convex ring;

[0020] The outer side surfaces of the first sealing convex ring and the second sealing convex ring form a sliding layer in contact with the inner side wall of the syringe, and the sliding layer does not use lubricating oil as a lubricating medium.

[0021] A sealing ring is provided between the needle assembly and the inner wall of the needle cavity, and at least two sealing rings are provided.

[0022] A snap fit piece is provided at the lower end of the push rod, and a snap fit hole which can be connected and fixed with the snap fit piece is formed at the upper end of the sealing piston.

[0023] The beneficial effects of the present invention are:

[0024] After the syringe completes aspiration, bubbles adhere to the tapered guide hole of the locking inner bore, preventing them from being expelled through conventional venting. When the injection is complete, as the sealing piston descends, the hook on the upper end of the needle assembly first engages the tapered guide hole. As the sealing piston elastically deforms, the hook then moves from the straight hole into the tapered locking inner bore. Simultaneously, the abutting curved surface on the opposite side of the hook also engages from the tapered guide hole into the locking inner bore. During this process, the locking inner bore and the hook fully cooperate, and the sealing piston descends to the lowest point of the syringe, i.e., to its lowest point, forming a first slow-flow gap between the lower surface of the sealing piston and the stepped surface of the syringe. This prevents bubbles from entering the needle channel under pressure after the injection is completed. Combined with the drainage design of the tapered guide hole, bubbles are pushed by the hook and the abutting curved surface, eventually moving along the tapered guide hole into the tapered locking hole, preventing them from being injected into the body along with the needle, thus ensuring injection safety. Furthermore, the second slow-flow gap formed by the avoidance portion and the inner side wall of the straight hole provides space for temporary storage of bubbles, further preventing bubbles from entering the needle channel.

[0025] 2. The aspiration and injection procedures of this syringe are identical to those of conventional syringes. After injection is completed, the hook engages the sealing piston's inner hole as the sealing piston gradually moves downward. At this point, the arcuate abutment surface on the opposite side of the hook is abutted by the tapered guide hole and the sidewall of the straight hole in the inner hole. This arcuate abutment surface cannot fully engage the inner hole, causing the lower end of the needle assembly to tilt toward the hook, resulting in a tendency for the central axis of the needle assembly to shift. Due to the elastic deformation of the sealing piston, as the sealing piston continues to move downward, the tapered locking hole and the barb are fully engaged. After the injection is completed, the push rod is pulled upward, causing the sealing piston to move upward, simultaneously pulling the needle assembly upward. Due to the elastic force of the tapered guide hole and the sidewalls of the straight hole on the abutting curved surface, the central axis of the needle assembly tilts about the midpoint of the needle assembly's upper end surface. This further causes the second boss below the same side of the abutting curved surface to disengage from the lower step surface. Finally, as the push rod is pulled upward, the needle assembly disengages the needle cavity and retracts into the syringe cavity, completing the needle's retraction and self-destruction. Once the needle assembly is pulled back into the syringe cavity by the sealing piston, the needle tip abuts the inner wall of the syringe cavity. Restricted by the syringe step surface, the needle can no longer be pushed out of the syringe, achieving 100% needle retraction and self-destruction. This disposable design eliminates the risks of cross-infection and reuse, ensuring the safety of medical personnel during the injection process. It is 100% safe from cross-infection and needle puncture during recovery, thereby reducing recycling costs and ensuring safety for national or professional institutions.

[0026] 3. The second boss of the needle assembly abuts against the lower step surface of the convex ring of the needle cavity, effectively preventing the needle from retreating due to the resistance of the skin and tissue during the injection process, thereby achieving safe injection. Furthermore, the needle is mainly installed between the first conical channel and the second conical channel in the needle channel, and the conical channel further prevents the needle from retreating; the first arc channel and the second arc channel can increase the sealing between the needle and the needle assembly, effectively preventing the leakage of the liquid medicine. Furthermore, as the central axis of the needle assembly deviates, the abutment contact surface between the second boss and the lower step surface decreases, and finally, under the action of a certain elastic deformation, the second boss separates from the lower step surface. These designs enable the needle to withstand greater resistance from the skin and tissue during the injection process without retreating, and only a small pulling force is required to pull back the needle after the injection is completed, completing the retreat and self-destruction of the needle, which is more convenient to use.

[0027] 4. A sealing relationship is formed between the syringe and the sealing piston through the first sealing convex ring and the second sealing convex ring to ensure the smoothness of pushing and pulling the push rod, and this process can be easily achieved without the need for lubricating oil or silicone oil. Figure 5No lubricant is required between the syringe barrel and the sealing piston, as shown at D in the middle; the needle assembly is disengaged from the needle cavity through structural design, completing its retraction. This process can be easily accomplished without the use of lubricating oil or silicone oil, eliminating the lubricating effect of lubricating oil or silicone oil, allowing each operation to be completed smoothly. Desilicone-ization of the syringe, on the one hand, prevents irritation or inflammatory reactions caused by silicone oil in the human body, which can lead to reduced efficacy or unpredictable consequences, and avoid possible allergic reactions. On the other hand, it reduces potential chemical residues and the risk of biological reactions caused by these substances, thereby significantly improving the biocompatibility of the product and making a significant contribution to human health.

[0028] This "oil-free lubrication" technology is an important development direction in the field of medical devices. Its advantages are mainly reflected in the following aspects:

[0029] a. Completely eliminate the risk of silicone oil migration and its related adverse reactions:

[0030] Zero migration: The most fundamental advantage is that it completely eliminates the possibility of silicone oil (even medical grade) migrating from the inner wall of the syringe into the drug solution and ultimately being injected into the human body. Avoiding silicone oil-related complications directly avoids the following possible consequences of silicone oil migration:

[0031] Injection site reactions, such as local pain, redness, swelling, nodules, sterile abscesses, and granuloma formation (foreign body reaction). Intravascular risks: Theoretically, the risk of thromboembolism caused by silicone oil dripping into the blood is reduced to zero. Long-term accumulation concerns: For patients who require frequent injections (such as insulin and biologics), concerns about the potential effects of long-term trace silicone oil accumulation are eliminated. Allergy risks: The possibility of allergy to silicone oil components is completely eliminated.

[0032] b. Significantly improve drug compatibility and stability:

[0033] Preventing drug adsorption / inactivation: Silicone membranes are hydrophobic and easily adsorb large molecules such as proteins, peptides, and monoclonal antibodies, as well as certain hydrophobic small molecules. This can result in: decreased effective drug concentration and reduced efficacy; conformational changes, aggregation, or inactivation of the drug, impacting safety and efficacy; and altered drug release kinetics.

[0034] Maintaining drug purity: A silicone-free environment reduces the chance of drug interaction with foreign substances (silicone oil), helping to maintain the original purity and stability of drug formulations, which is especially important for high-value, highly sensitive biologics (such as vaccines, monoclonal antibodies, gene therapy products, and cell therapy products).

[0035] Simplified formulation development: When developing drugs that are sensitive to silicone oil, pharmaceutical companies do not need to invest a lot of effort in studying drug-silicone oil interactions or finding stabilizers, reducing R&D difficulty and cost.

[0036] c. Reduce particulate pollution:

[0037] Eliminate silicone oil-related particles: The silicone oil film may flake off during repeated piston movement (such as pre-injection mixing) or storage, forming tiny oil droplets, or interact with the rubber piston components to produce silicone oil-rubber composite particles. The silicone oil-free design fundamentally eliminates the source of these particles.

[0038] Improve product cleanliness: The number of particles generated by the syringe system is reduced overall (although other sources such as glass and rubber particles still need to be controlled), meeting the increasingly stringent pharmacopoeia limit requirements for insoluble particles in injections and improving medication safety.

[0039] d. Meeting special medical needs:

[0040] Ophthalmology: Intraocular injections (such as intravitreal injections) are extremely demanding in terms of particle and foreign body residue. Even tiny amounts of silicone oil can cause serious complications (such as blurred vision, inflammation, and even silicone oil emulsification leading to increased intraocular pressure). Oil-free syringes are ideal for these procedures.

[0041] Neurosurgery / Intraspinal Injection: The central nervous system is extremely sensitive to foreign matter, and the oil-free design can minimize the risk of introducing exogenous substances.

[0042] Patients with contraindications to silicone oil: Theoretically, it provides a safer option for patients with a clear history of allergy to silicone oil (although allergies to medical silicone oil are extremely rare).

[0043] e. Improve patient experience and safety:

[0044] Reduced injection pain: Local tissue reactions associated with silicone oil are one of the causes of injection pain. The oil-free design may help reduce pain during injection and improve patient compliance, especially for patients who require long-term injections (such as diabetics).

[0045] Reduce long-term injection complications: For frequent injection sites, it can reduce the occurrence of chronic inflammatory reactions such as granulomas, and help protect the health of the skin and tissues at the injection site. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a cross-sectional schematic diagram of the syringe;

[0047] Figure 2 yes Figure 1 A partial enlarged view of point A in the middle;

[0048] Figure 3 is a schematic diagram of the needle assembly;

[0049] Figure 4It is a cross-sectional schematic diagram of the syringe cavity and the needle cavity;

[0050] Figure 5 is a cross-sectional schematic diagram after the sealing piston and the needle assembly are fastened together;

[0051] Figure 6 It is a cross-sectional schematic diagram of a self-destructing syringe in the prior art;

[0052] Figure 7 It is a cross-sectional view of the sealing piston pulling the needle assembly back into the syringe cavity. DETAILED DESCRIPTION

[0053] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the drawings only show portions relevant to the present invention, not all of them.

[0054] Reference Figure 1 The present invention proposes a disposable sterile silicone-free retractable self-destructive safety syringe, comprising a syringe 1, a push rod 2 disposed in the syringe 1, a sealing piston 3 disposed at the lower end of the push rod 2 and connected thereto, and a needle assembly 4 mounted at the lower end of the syringe 1. The needle assembly 4 is fixedly mounted in a needle cavity 14 at the lower end of the syringe 1, and the upper end of the needle assembly 4 is located in the barrel cavity 10 of the syringe 1. A hook 40 is formed on one side of the upper end of the needle assembly 4, and an abutting arc surface 41 is formed on the opposite side of the hook 40; a buckle inner hole 30 capable of cooperating with the hook 40 is formed at the lower end of the sealing piston 3;

[0055] Reference Figure 3 The buckling inner hole 30 includes a straight hole 300, a tapered guide hole 302 with a diameter gradually increasing from top to bottom is formed between the lower end of the straight hole 300 and the lower bottom surface of the sealing piston 30, and a tapered buckling hole 301 is formed at the upper end of the straight hole 300;

[0056] Reference Figure 5 A syringe step surface 12 is formed at the lower end of the syringe cavity 10. When the buckling inner hole 30 and the hook 40 are buckled together, the sealing piston 3 moves down to the lowest end, and a first slow flow gap 100 is formed between the lower surface of the sealing piston 3 and the syringe step surface 12.

[0057] Furthermore, a side-concave avoidance portion 42 is formed below the hook 40. When the buckle inner hole 30 and the hook 40 are buckled together, the sealing piston 3 moves down to the lowest end, and a second slow-flow gap 420 is formed between the avoidance portion 42 and the inner wall of the straight hole 300.

[0058] Specifically, after the syringe has completed aspiration, bubbles adhere to the tapered guide hole 302 of the buckling inner hole 30, and at this time the bubbles cannot be discharged through conventional exhaust operations. When the injection is completed, as the sealing piston 3 moves downward, the hook 40 at the upper end of the needle assembly 4 first embeds into the tapered guide hole 302. As the sealing piston 3 elastically deforms, the hook 40 then enters the tapered buckling hole 301 from the straight hole 300. At the same time, the abutting arc surface 41 on the opposite side of the hook 40 also embeds into the buckling inner hole 30 from the tapered guide hole 302. During this process, the buckling inner hole 30 and the hook 40 are fully matched, and the sealing piston 5 moves down to the bottom of the syringe 1, that is, the sealing piston 5 moves to the bottom of the line. At the bottom of the injection process, a first slow-flow gap 100 is formed between the lower surface of the sealing piston 5 and the stepped surface 12 of the syringe. After the injection is completed, the first slow-flow gap 100 can prevent bubbles from entering the needle channel 43 under the action of squeezing. Combined with the drainage design of the tapered guide hole 302, the bubbles are pushed by the hook 40 and the abutting arc surface 41, and eventually the bubbles can gradually move along the tapered guide hole 302 into the tapered buckle hole 301, and will not be injected into the human body along with the needle, ensuring the safety of the injection. Furthermore, the second slow-flow gap 420 formed by the avoidance portion 42 and the inner side wall of the straight hole 300 provides space for temporary storage of bubbles, further preventing bubbles from entering the needle channel.

[0059] Reference Figure 5 、 Figure 6 When the buckle inner hole 30 is matched with the hook 40, as the push rod 2 is pulled, the sealing piston 3 can drive the needle assembly 4 to move upward, so that the needle assembly 4 can be disengaged from the needle cavity 14; the abutting arc surface 41 can gradually abut against the buckle inner hole, so that the central axis of the needle assembly 4 and the central axis of the syringe 1 are deflected. The needle assembly 4 includes a needle. When the needle assembly 4 is pulled to the syringe cavity 10, the needle tip at the front end of the needle is offset and abuts against the inner wall of the syringe cavity 10. Furthermore, the design of the avoidance portion 42 also allows the needle assembly 4 to be better offset under the action of the abutting arc surface 41 on the opposite side of the hook 40 when the hook 40 enters the buckle inner hole 30. When the needle assembly 4 is pulled back into the syringe cavity 10 by the sealing piston 3, the needle tip at the front end of the needle abuts against the inner wall of the syringe cavity 10, and under the restriction of the syringe step surface 12, the needle can no longer be pushed out of the syringe 1, and the needle achieves a 100% retraction and self-destruction effect.

[0060] Reference Figure 2 、 Figure 3 The hook 40 includes a guide slope 400 at the top and a barb 401 located below the guide slope 400; the conical buckle hole 301 includes a conical inner hole 3010 that can cooperate with the guide slope 400, and a buckle step 3011 that can cooperate with the barb 401 is formed between the conical inner hole 3010 and the straight hole 300.

[0061] Reference Figure 4 The needle cavity 14 includes a convex ring 11, an upper step surface 110 is formed on the convex ring 11, a lower step surface 111 is formed below the convex ring 11, and an inverted cone slope 13 is formed below the lower step surface 111;

[0062] Reference Figure 3 、 Figure 4 A first boss 46 is provided below the same side of the hook 40, and the bottom of the first boss 46 can abut against the upper step surface 110 to limit the downward movement of the needle assembly 4; a second boss 44 is provided below the same side of the abutting arc surface 41, and the second boss 44 can abut against the lower step surface 111.

[0063] Specifically, the liquid aspiration and injection operations of this syringe are the same as those of an ordinary syringe. When the injection is completed, first, as the sealing piston 3 gradually moves downward, the hook 40 is embedded in the buckling inner hole 30 of the sealing piston 3. At this time, the abutting arc surface 41 on the opposite side of the hook 40 is abutted by the tapered guide hole 302 and the side wall of the straight hole 300 of the buckling inner hole 30. The abutting arc surface 41 cannot be completely embedded in the buckling inner hole 30, so that the lower end of the needle assembly 4 tends to tilt toward the hook direction 40, that is, the central axis of the needle assembly 4 tends to be offset. Since the sealing piston 3 has the ability to elastically deform, as the sealing piston 3 continues to move downward, the tapered buckling hole 301 and the barb 401 are buckled together. Specifically, the thrust of the upper part of the needle assembly 4 buckling into the buckling inner hole 30 is less than 10N, and the medical staff can use it more easily.

[0064] After the injection is completed, the push rod 2 is pulled upward, the sealing piston 3 moves upward, and the needle assembly 4 is pulled upward at the same time. Due to the elastic force of the tapered guide hole 302 and the side wall of the straight hole 300 on the abutting arc surface 41, the central axis of the needle assembly 4 tilts around the midpoint of the upper end surface of the needle assembly 4, further causing the second boss 44 below the same side of the abutting arc surface 41 to separate from the lower step surface 111. Finally, as the push rod 2 is pulled upward, the needle assembly 4 disengages the needle cavity 14 and retracts into the syringe cavity 10, completing the needle's retraction and self-destruction. This disposable design avoids the risks of cross-infection and reuse, ensuring the safety of medical personnel during the injection process.

[0065] Reference Figure 3 A needle channel 43 communicating with the syringe cavity 10 is provided in the needle assembly 4. The needle channel 43 includes a first tapered channel 431 and a first arc-shaped channel 432 provided below the first tapered channel 431 and having an arc-shaped sidewall.

[0066] A second curved channel 4320 is further provided below the first curved channel 432 , and a second tapered channel 4310 is further provided below the second curved channel 4320 ;

[0067] The needle channel 43 further includes a fluid channel 430 connected to the upper side of the first tapered channel 431 . The needle of the syringe is installed below the fluid channel 430 , and the upper end of the fluid channel 430 is connected to the syringe cavity 10 .

[0068] Furthermore, the second boss 44 of the needle assembly 4 abuts the lower stepped surface 111 of the convex ring 11 of the needle cavity 10, effectively preventing the needle from retreating due to resistance from the skin and tissue during injection, ensuring safe injection. Specifically, when the sealed piston in the syringe cavity 10 pushes the liquid medicine at a speed of 200 mm / min, the needle assembly 4 can withstand a pressure of ≤15 N. Furthermore, the needle is primarily mounted between the first tapered channel 431 and the second tapered channel 4310 within the needle channel 43. This tapered channel further prevents the needle from retreating. The first and second curved channels 432 and 4320 enhance the seal between the needle and the needle assembly 4, effectively preventing leakage of the liquid medicine. Furthermore, as the central axis of the needle assembly 4 deviates, the contact surface between the second boss 44 and the lower stepped surface 111 decreases. Ultimately, due to a certain degree of elastic deformation, the second boss 44 disengages from the lower stepped surface 111. These designs allow the needle to withstand greater resistance from the skin and tissues without retreating during the injection process. After the injection is completed, only a small pulling force is needed to pull back the needle, completing the needle's retreat and self-destruction, making it more convenient to use.

[0069] Reference Figure 2 The side of the sealing piston 3 is formed with a first sealing convex ring 32 and a second sealing convex ring 33 that can cooperate with the inner wall of the syringe 1. The lower edge of the first sealing convex ring 32 is connected to the lower bottom surface of the sealing piston 3, that is, the second sealing convex ring 33 is arranged above the first sealing convex ring 32. Specifically, the lower edge line of the first sealing convex ring 32 is connected to the lower bottom surface of the sealing piston 3, that is, a transitional chamfer is provided between them. The outer side surfaces of the first sealing convex ring 32 and the second sealing convex ring 33 form a sliding layer in contact with the inner side wall of the syringe 1, and the sliding layer does not use lubricating oil as a lubricating medium. Specifically, the first sealing convex ring 32 and the lower bottom surface of the sealing piston 3 have a smooth transition, ensuring the smoothness of the sealing piston 3 when it moves downward to push the liquid medicine and reducing the resistance during pushing. The second sealing convex ring 33 can ensure the sealing between the sealing piston 3 and the syringe 1. The coordination of this structure ensures that the syringe syringe 1 and the sealing piston 3 can ensure their reliability in use without relying on the use of lubricants such as silicone oil.

[0070] Furthermore, the push-pull force between the sealing piston 3 and the inner wall of the syringe 1 is less than 5.5N in the absence of additives such as lubricants and lubricants, which ensures the hand feel while ensuring that the drug solution is not contaminated, thereby ensuring the safety of patients using the drug.

[0071] Reference Figure 5A sealing ring 45 is provided between the needle assembly 4 and the inner wall of the needle cavity 14. Preferably, at least two sealing rings 45 are provided.

[0072] Reference Figure 2 A snap fit member 20 is provided at the lower end of the push rod 2 , and a snap fit hole 31 which can be connected and fixed with the snap fit member 20 is formed at the upper end of the sealing piston 3 .

[0073] Specifically, when the needle assembly 4 is fully retracted into the syringe cavity 10, the distance between the needle tip and the lower end of the syringe 1 (the syringe step surface 12) must be ≥ 2 mm. The force required to pull the latch 20 of the push rod 2 out of the latch hole 31 must be ≥ 25 N, and the breaking force of the push rod 2 must be ≤ 20 N. This ensures that the needle assembly 4 can smoothly retract into the syringe cavity 10 and complete self-destruction.

[0074] Furthermore, a sealing relationship is formed between the syringe 1 and the sealing piston 3 by the first sealing convex ring 32 and the second sealing convex ring 33, which ensures the smoothness of pushing and pulling of the push rod 2, and this process can be easily achieved without the use of lubricating oil or silicone oil; the needle assembly 4 is separated from the needle cavity 14 by relying on the structural design to complete the retraction of the needle assembly 4, and this process can also be easily achieved without the use of lubricating oil or silicone oil. By avoiding the lubricating effect of lubricating oil or silicone oil, each operation can be completed smoothly. The desiliconeization of the syringe can, on the one hand, avoid the irritation or inflammatory reaction caused by silicone oil to the human body, resulting in reduced efficacy or unpredictable consequences, and avoid possible allergic reactions. On the other hand, it reduces potential chemical residues and reduces the risk of biological reactions that may be caused by these substances, thereby significantly improving the biocompatibility of the product.

Claims

1. A disposable sterile, silicone-free, retractable, self-destructive safety syringe comprising a syringe (1), a push rod (2) disposed within the syringe (1), a sealing piston (3) disposed at and connected to the lower end of the push rod (2), and a needle assembly (4) mounted at the lower end of the syringe (1), characterized in that: The needle assembly (4) is fixedly mounted in the needle cavity (14) at the lower end of the syringe (1), and the upper end of the needle assembly (4) is located in the syringe cavity (10) of the syringe (1). A hook (40) is formed on one side of the upper end of the needle assembly (4), and an abutting arc surface (41) is formed on the opposite side of the hook (40); The lower end of the sealing piston (3) is formed with a buckle inner hole (30) capable of cooperating with the hook (40), the buckle inner hole (30) includes a straight hole (300), a tapered guide hole (302) with a diameter gradually increasing from top to bottom is formed between the lower end of the straight hole (300) and the lower bottom surface of the sealing piston (30), and a tapered buckle hole (301) is formed at the upper end of the straight hole (300); A syringe step surface (12) is formed at the lower end of the syringe cavity (10). When the buckling inner hole (30) and the hook (40) are buckled together, the sealing piston (3) moves down to the lowest end of the stroke, and a first slow flow gap (100) is formed between the lower surface of the sealing piston (3) and the syringe step surface (12).

2. A disposable sterile silicone oil-free retractable self-destructive safety syringe according to claim 1, characterized in that: A side-concave avoidance portion (42) is formed below the hook (40). When the buckle inner hole (30) and the hook (40) are buckled together, the sealing piston (3) moves down to the lowest end of the stroke, and a second slow-flow gap (420) is formed between the avoidance portion (42) and the inner side wall of the straight hole (300).

3. A disposable sterile silicone oil-free retractable self-destructive safety syringe according to claim 1, characterized in that: When the buckle inner hole (30) is engaged with the hook (40), as the push rod (2) is pulled, the sealing piston (3) can drive the needle assembly (4) to move upward, so that the needle assembly (4) is disengaged from the needle cavity (14); the abutting arc surface (41) can gradually abut against the side wall of the buckle inner hole (3), so that the central axis of the needle assembly (4) and the central axis of the syringe (1) are deflected; The needle assembly (4) includes a needle. When the needle assembly (4) is pulled into the syringe cavity (10), the needle tip at the front end of the needle deviates and abuts against the inner wall of the syringe cavity (10).

4. A disposable sterile silicone oil-free retractable self-destructive safety syringe according to claim 1, characterized in that: The hook (40) comprises a top guide slope (400) and a barb (401) located below the guide slope (400); the conical buckle hole (301) comprises a conical inner hole (3010) capable of cooperating with the guide slope (400); and a buckle step (3011) capable of cooperating with the barb (401) is formed between the conical inner hole (3010) and the straight hole (300).

5. A disposable sterile silicone oil-free retractable self-destructive safety syringe according to claim 1, characterized in that: The needle cavity (14) comprises a convex ring (11), an upper step surface (110) is formed on the upper surface of the convex ring (11), a lower step surface (111) is formed on the lower surface of the convex ring (11), and an inverted cone slope (13) is formed below the lower step surface (111); A first boss (46) is provided below the same side of the hook (40), and the lower side of the first boss (46) can abut against the upper step surface (110) to limit the downward movement of the needle assembly (4); a second boss (44) is provided below the same side of the abutting arc surface (41), and the second boss (44) can abut against the lower step surface (111).

6. A disposable sterile silicone oil-free retractable self-destructive safety syringe according to claim 1, characterized in that: The needle assembly (4) is provided with a needle channel (43) communicating with the syringe cavity (10), and the needle channel (43) comprises a first tapered channel (431) and a first arc-shaped channel (432) provided below the first tapered channel (431) and having an arc-shaped side wall.

7. A disposable sterile silicone oil-free retractable self-destructive safety syringe according to claim 6, characterized in that: A second curved channel (4320) is further provided below the first curved channel (432), and a second tapered channel (4310) is further provided below the second curved channel (4320); The needle channel (43) further includes a fluid channel (430) connected to the upper side of the first tapered channel (431). The lower side of the fluid channel (430) is used to mount the needle of the syringe. The upper end of the fluid channel (430) is connected to the syringe cavity (10).

8. A disposable sterile silicone oil-free retractable self-destructive safety syringe according to claim 1, characterized in that: The side surface of the sealing piston (3) is formed with a first sealing convex ring (32) and a second sealing convex ring (33) that can cooperate with the inner wall of the syringe (1); the lower edge line of the first sealing convex ring (32) is connected to the lower bottom surface of the sealing piston (3), and the second sealing convex ring (33) is arranged above the first sealing convex ring (32); The outer side surfaces of the first sealing convex ring (32) and the second sealing convex ring (33) form a sliding layer in contact with the inner side wall of the needle cylinder (1), and the sliding layer does not use lubricating oil as a lubricating medium.

9. A disposable sterile silicone oil-free retractable self-destructing safety syringe according to claim 1, characterized in that: A sealing ring (45) is provided between the needle assembly (4) and the inner wall of the needle cavity (14), and at least two sealing rings (45) are provided.

10. A disposable sterile silicone oil-free retractable self-destructive safety syringe according to claim 1, characterized in that: The lower end of the push rod (2) is provided with a snap-fitting piece (20), and the upper end of the sealing piston (3) is formed with a snap-fitting hole (31) that can be connected and fixed with the snap-fitting piece (20).

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