An implant injector

Abstract

The application discloses an implant injector, which comprises a shell, a needle element, a push rod and a cap. The side wall of the shell is provided with a first hole position and a third hole position. The needle element is slidably accommodated in the shell, and the side wall of the needle element is provided with a first elastic locking element and a second elastic locking element which protrude outward. The push rod is arranged in the needle element, and the side wall of the push rod is provided with a first protruding rib. The cap is detachably sleeved on the front end of the shell, and the side wall of the cap is provided with a second protruding rib. In the initial state, the cap is sleeved on the shell, the second protruding rib supports the second elastic locking element from the inside, and the protruding part of the second elastic locking element is embedded in the third hole position. The first protruding rib supports the first elastic locking element from the inside, and the protruding part of the first elastic locking element is embedded in the first hole position. The needle element is locked in the shell. The injector has simple structure, strict logic and high reliability, and realizes the whole-process safety closed loop from double insurance in transportation, one-way driving and prevention of retreat, forced time sequence injection to final state double irreversible interlocking.

Description

Technical Field

[0001] This application relates to the field of medical device technology, specifically to an implantable syringe. Background Technology

[0002] In the medical field, subcutaneous drug delivery is an important treatment method. It involves quantitatively delivering solid drugs (such as sustained-release sticks and micro-implants) into the patient's subcutaneous tissue to achieve a long-lasting and stable drug delivery effect. This procedure typically relies on a specialized syringe. However, existing implantable drug delivery devices still have several shortcomings in design and use, mainly in the following aspects: Firstly, regarding safety mechanisms, traditional syringes often only have a single safety pin at the plunger. If this safety pin accidentally falls off during transportation or storage, or is mistakenly pulled out, the core components of the syringe may be in a partially locked state, posing a risk of premature drug ejection due to accidental plunger activation, or accidental needle extension leading to injury. Traditional pen caps only serve as dustproof and needle tip protection, offering limited functionality and failing to provide additional safety locking features for syringes.

[0003] Secondly, there is a potential for incorrect sequence in the task logic of the injection procedure. Ideally, the drug injection should be completed first, followed by needle withdrawal; otherwise, it may result in serious failure, such as the needle being withdrawn before the drug is injected. Current technology lacks a rigid timing control mechanism to enforce the correct "inject first, withdraw later" operating sequence, making it highly dependent on the operator.

[0004] Furthermore, regarding the relationship between the push rod and the needle assembly, in order to prevent the push rod from accidentally slipping out of the needle assembly or being pulled out in the opposite direction due to misoperation after assembly, some existing solutions use complex elastic latches or multi-part combinations to achieve the anti-reverse function. This results in complex structures, difficult assembly, high costs, and reduced reliability due to the increase in the number of parts.

[0005] Finally, regarding the final safety locking after injection, some existing products only lock a single component at a single point, such as locking only the needle part or only the push rod. The locking strength is insufficient, and the locking relationship may be broken under external impact, resulting in the needle re-extending unexpectedly or the push rod being pushed out, leaving a safety hazard of needlestick injury.

[0006] In summary, how to build a comprehensive, multi-level, and highly reliable safety assurance system for implantable injectors, covering the entire process from transportation and storage to injection operation and final locking, is an urgent technical problem that needs to be solved. Summary of the Invention

[0007] To address the aforementioned issues, this application provides an implantable syringe that achieves a complete safety closed loop, from dual insurance during transportation, unidirectional drive anti-retrograde, forced sequential injection to final-state dual irreversible interlocks. Its simplified structure, rigorous logic, and high reliability significantly improve the safety of implantable syringes in all stages of transportation, operation, and disposal.

[0008] Specifically, the following technical solutions are included: This application provides an implantable syringe, comprising: The housing has a first hole and a third hole on its side wall; The pin is slidably accommodated within the housing, and its sidewalls are provided with a first elastic locking element and a second elastic locking element that protrude outwards. The push rod passes through the needle-bearing component, and its side wall is provided with a first protruding rib; The pen cap is detachably fitted onto the front end of the housing, and its side wall is provided with a second protruding rib; In the initial state, the pen cap is fitted onto the housing, the second protruding rib pushes against the second elastic locking member from the inside, so that the protruding part of the second elastic locking member is embedded in the third hole; and the first protruding rib pushes against the first elastic locking member from the inside, so that the protruding part of the first elastic locking member is embedded in the first hole; so as to lock the pin-shaped member to the housing.

[0009] In one embodiment of this application, the push rod sidewall is provided with a groove, which is configured such that when the push rod moves downward to the injection end position, the groove aligns with the first elastic locking member, providing the first elastic locking member with inward retraction clearance space to allow the needle-carrying member to move upward relative to the housing.

[0010] In one embodiment of this application, the side wall of the housing is further provided with a second elongated groove extending along the axial direction and a second hole communicating with the second elongated groove; the side wall of the pin-shaped component is further provided with a second buckle; When the needle retraction is complete, the second buckle slides to the top of the second long groove and abuts against the stop end face provided at the top of the second long groove; and the first protruding rib of the push rod pushes the second elastic locking member from the inside, so that its protruding part is embedded in the second hole; to lock the needle member and the housing.

[0011] In one embodiment of this application, oblique strip holes are provided on both sides of the second hole, and an outwardly expandable deformable portion is formed in the area between the oblique strip holes and the second long groove.

[0012] In one embodiment of this application, the needle-carrying component has an axially extending receiving cavity inside, and the wall of the needle-carrying component has a first elongated groove that communicates with the receiving cavity and extends axially. The inner wall of the first elongated groove has a first protrusion; the outer wall of the push rod has a first buckle. The first latch is configured to slide along the first elongated groove and pass over the first protrusion when the push rod is pushed downward in the axial direction; when the push rod is subjected to an external force in the axial direction, the upper end face of the first latch abuts against the inner top surface of the first elongated groove to restrict the upward movement of the push rod.

[0013] In one embodiment of this application, the inner wall of the receiving cavity is further provided with a sliding groove located above and aligned with the first long groove, for guiding the first buckle to slide downward into the first long groove.

[0014] In one embodiment of this application, the top of the needle-bearing component is provided with an embedding groove; the top of the push rod is provided with a top plate, and the side of the top plate is provided with outwardly protruding ribs; When the needle retraction is complete, the top plate is embedded in the embedding groove, and the protruding rib forms an interference fit with the inner sidewall of the embedding groove to lock the push rod and the needle-carrying component.

[0015] In one embodiment of this application, a safety pin is further included, the safety pin having a buckle; in the initial state, the safety pin is sleeved on the outer wall of the push rod and abuts against the pin-bearing member, the buckle being engaged in the groove of the side wall of the push rod to lock the push rod to the pin-bearing member.

[0016] In one embodiment of this application, the bottom of the needle-bearing component is fixedly connected to a needle and a drug reservoir; the drug reservoir stores solid drugs, and the side wall of the drug reservoir is provided with a third elastic locking member, the interior of which is provided with an internal protrusion for fixing the solid drugs; a drug-pushing rod is fixedly installed inside the push rod, and the drug-pushing rod is movably inserted through the drug reservoir and the needle.

[0017] In one embodiment of this application, the housing is further provided with an internal rib; at the end of the injection, the first buckle presses against the top of the internal rib to limit the injection stroke of the push rod.

[0018] The beneficial effects of this application are: 1. The implant syringe provided in this application, based on the traditional safety pin locking push rod, utilizes a pen cap from the packaging as the trigger element of a second locking device to firmly lock the needle component to the housing. Even if the safety pin accidentally falls off, as long as the pen cap is not removed, the core components of the syringe remain fully locked, fundamentally avoiding the risk of accidental triggering during transportation and storage, providing multiple layers of protection and enhanced safety. Furthermore, this safety mechanism is perfectly integrated with the normal usage process. The operator must first remove the pen cap before proceeding with subsequent operations; this step, while removing the needle tip protection, also automatically releases the second locking of the needle component. The entire process is seamless, without adding any additional operating steps or learning costs; the operating logic is natural and requires no additional learning. In addition, the high-value safety function is achieved by cleverly adding functional ribs to the essential packaging component, the pen cap, without significantly increasing mold and manufacturing costs. The structure is ingenious, the packaging component is reusable, and it is extremely economical.

[0019] 2. This application establishes a conditional unlocking relationship between the push rod and the needle-carrying component, mechanically locking the correct operational sequence of "injection completed before needle withdrawal." Specifically, in the initial state and throughout the injection process, the first protruding rib on the push rod's side wall consistently supports the first elastic locking element on the needle-carrying component from the inside, causing its protruding portion to embed into the first hole in the housing, thereby forcibly locking the needle-carrying component within the housing and preventing upward needle withdrawal. Only when the push rod is fully pressed to the injection end position, i.e., the moment when all the medication has been ejected, will the groove on the push rod's side wall move precisely to a position horizontally aligned with the first elastic locking element, providing space for the first elastic locking element to retract inward. At this point, the upward needle withdrawal path of the needle-carrying component is unlocked. This design ensures that the needle withdrawal action can only be performed after the prerequisite of complete injection is met, structurally eliminating the serious failure mode of "needle withdrawal before injection," completely eliminating reliance on the operator's subjective experience and attention, and greatly improving the reliability and safety of the injection operation.

[0020] 3. The implant syringe provided in this application requires no additional springs, pins, or other independent parts. It achieves its anti-reverse function entirely through the cooperation between the first latch of the push rod, the first protrusion of the needle-bearing component, and the first long groove. This greatly simplifies the equipment structure and assembly process, significantly reducing production costs. The structure is extremely simple and the cost is low. Furthermore, employing a hard-locking physical anti-reverse principle, once the first latch is embedded between the inner top surface of the first protrusion and the first long groove, any external force attempting to pull the push rod upwards axially will only cause the upper surface of the first latch to press more tightly against the inner top surface of the first long groove, forming a rigid contact relationship. Thus, the upward movement of the push rod is physically and irreversibly locked. This locking is a hard-locking anti-reverse fit; unless the structure of the push rod or the needle-bearing component is intentionally damaged, the lock cannot be released. In addition, during assembly, simply pushing the push rod downwards into the needle-bearing component, allowing the first latch of the push rod to pass through the groove and enter the first long groove, automatically establishes the anti-reverse function, making the assembly process highly efficient.

[0021] 4. The implantable syringe provided in this application, through precise structural timing, triggers a two-stage locking mechanism simultaneously at the final position of the natural completion of the needle withdrawal action. The first locking is formed by the interference fit between the protruding rib on the top plate of the push rod and the insertion groove of the needle component, locking the two core moving parts, the push rod and the needle component, into an inseparable whole, making it impossible for the push rod to be pushed further or pulled outward. The second locking is formed by the abutment between the second buckle on the needle component and the stop end face of the second long groove on the shell, and the insertion fit between the second elastic locking element and the second hole, structurally limiting the entire upward and downward movement path of the needle component. This double interlocking is no longer a single-point jamming of a single component, but rather makes the push rod and the needle component interlock with each other, forming a cage for each other, and completely locking the entire interlocking system in the axial direction of the shell, fundamentally eliminating the hidden dangers of the push rod dislodging or the needle tip accidentally re-extending due to external impact or deliberate prying, significantly improving the final state safety of disposable injection devices. Furthermore, this syringe achieves a high-strength dual self-locking function without introducing any additional springs, locking pins, screws, or other independent parts, and without requiring any additional assembly processes. This not only means lower material and assembly costs, but also fundamentally eliminates reliability risks such as fatigue, creep, and detachment that may occur after long-term storage or transportation of additional parts, ensuring the long-term stability of the locking function and achieving the highest safety value with the simplest structure. Attached Figure Description

[0022] Figure 1 This is an exploded view of the implant syringe used in this application.

[0023] Figure 2 This is a front view of the implant syringe in its initial state.

[0024] Figure 3 This is a cross-sectional view of the implant syringe of this application in its initial state.

[0025] Figure 4 for Figure 3 A magnified view of A in the middle.

[0026] Figure 5 for Figure 3 A magnified view of B in the middle.

[0027] Figure 6 This is a perspective view of the push rod in this application.

[0028] Figure 7 This is a perspective view of the pin-shaped component in this application.

[0029] Figure 8 A perspective view of the safety pin for this application.

[0030] Figure 9 This is a perspective view of the casing of this application.

[0031] Figure 10 This is a cross-sectional view of the casing of this application.

[0032] Figure 11 This is a perspective view of the drug storage tube in this application.

[0033] Figure 12 This is a cross-sectional view of the drug storage tube in this application.

[0034] Figure 13 This is a perspective view of the pen cap of this application.

[0035] Figure 14 This is a cross-sectional view of the implant syringe of this application in the state after injection.

[0036] Figure 15 This is a cross-sectional view of the implant syringe of this application in the needle withdrawal end position.

[0037] In the diagram: 1. Push rod; 11. Top plate; 12. Protruding rib; 13. Groove; 14. First protruding rib; 15. First buckle; 151. Inclined surface; 2. Push rod; 3. Needle-equipped component; 31. Embedded groove; 32. First protrusion; 33. First elastic locking component; 34. First long groove; 341. Inner top surface; 35. Second buckle; 36. Fixed end of drug reservoir tube; 37. Second elastic locking component; 38. Needle fixed end; 39. Receiving cavity; 391. Slide groove; 4. Safety pin; 41. 42. Grip; 43. Flanged edge; 5. Inverted edge; 5. Housing; 51. First hole; 52. Second long groove; 521. Stop face; 53. Second hole; 54. Third hole; 55. Internal rib; 56. Axial slide; 57. Oblique strip hole; 58. Deformable part; 6. Drug reservoir; 61. Third elastic locking element; 62. Fixing part; 63. Internal protrusion; 7. Needle; 8. Pen cap; 81. First locking point; 82. Second locking point; 83. Second protruding rib; 9. Solid drug. Detailed Implementation

[0038] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0040] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0041] like Figures 1 to 15As shown, this application provides an implantable syringe for percutaneously implanting a solid drug 9 into a patient's body. Through the precise coordination of its components, this implantable syringe achieves a complete safety closed loop, including dual insurance for transportation and storage, unidirectional drive to prevent retraction, forced sequential injection, automatic unlocking and needle withdrawal after injection, and dual irreversible self-locking after needle withdrawal. The implantable syringe includes a plunger 1, a drug delivery rod 2, a needle-bearing component 3, a safety pin 4, a housing 5, a drug reservoir 6, a needle 7, and a pen cap 8; wherein the needle-bearing component 3 is slidably housed within the housing 5, the plunger 1 passes through the needle-bearing component 3, and the pen cap 8 is detachably fitted onto the front opening of the housing 5.

[0042] In some embodiments, the push rod 1 is a hollow cuboid structure with a top plate 11 for finger pressing. The top plate 11 has a ring of outwardly protruding ribs 12 along its side. In this embodiment, the ribs 12 are thin-walled protrusions extending continuously around the four side walls of the top plate 11. In other optional embodiments, the ribs 12 may also be a plurality of discontinuous protrusions or bumps distributed on each side.

[0043] Optionally, the push rod 1 has a groove 13 on its side wall for engaging with the safety pin 4 in the initial state. A first protruding rib 14 extending axially is provided below the side wall of the push rod 1. This first protruding rib 14 is a slender strip-shaped rib extending from the bottom end to the top end of the push rod 1. Its extension length is configured such that when the push rod 1 is in the initial position, the outer surface of the first protruding rib 14 can support the first elastic locking member 33 on the pin-shaped member 3 from the inside. The bottom outer wall of the push rod 1 also has an outwardly extending first buckle 15. This first buckle 15 is a protruding structure extending outward from the side wall of the push rod 1 body. Its upper end face is flat, and its side has a downwardly sloping surface 151, which facilitates the first buckle 15 sliding from the groove 391 of the pin-shaped member 3 into the first long groove 34.

[0044] In some embodiments, the push rod 2 is a solid cylinder, fixedly installed in the center of the push rod 1 and extending out of the push rod 1, together with the push rod 1 forming a push rod assembly.

[0045] In some embodiments, the needle-bearing component 3 is a hollow cuboid tubular structure with an axially extending receiving cavity 39 inside for inserting and guiding the push rod 1 to slide. An embedding groove 31 is provided at the top of the needle-bearing component 3, and the outer contour of the top plate 11 of the push rod 1 is adapted to the opening of the embedding groove 31 so that the top plate 11 can be embedded into the embedding groove 31. Preferably, both the top plate 11 and the embedding groove 31 are rectangular structures.

[0046] Due to the presence of the rib 12, the maximum external dimension of the top plate 11 at the location of the rib 12 is designed to be slightly larger than the corresponding opening size of the insertion groove 31, thus forming a preset interference fit between the two. To ensure smooth assembly and guide stable locking, the opening of the insertion groove 31 may be provided with an inlet bevel or a rounded corner. When the push rod 1 completes the drug injection and needle withdrawal actions and moves relative to the needle-carrying component 3 to a retracted locking position, the top plate 11 at the top of the push rod 1 is completely pressed into and embedded in the insertion groove 31 at the top of the needle-carrying component 3. The main body of the top plate 11 is placed in the cavity of the insertion groove 31, and at the same time, the rib 12 on its side interferes with the inner wall of the insertion groove 31 and forms a tight interference fit. Once this interference fit is established, a radial clamping force is generated, which firmly locks the push rod 1 onto the needle-carrying component 3. Without destructive operation, the push rod 1 cannot be pushed down or pulled up.

[0047] Optionally, a first elastic locking member 33 and a second elastic locking member 37 are sequentially provided from top to bottom on the side wall of the needle-bearing member 3. Both the first elastic locking member 33 and the second elastic locking member 37 are cantilevered or sheet-like elastic bodies extending from the side wall matrix of the needle-bearing member 3. In the free state, the protruding portions at both ends elastically open outward and protrude from the outer side wall surface of the needle-bearing member 3.

[0048] Optionally, the side wall of the needle-carrying component 3 is further provided with an outwardly protruding second latch 35, which is used to cooperate with the second elongated groove 52 of the housing 5 to limit the needle retraction limit position. Specifically, the second latch 35 is adapted to the second elongated groove 52 of the housing 5 so that the second latch 35 is slidably accommodated in the second elongated groove 52 and can slide up and down along the extension direction of the second elongated groove 52 with the needle-carrying component 3. When the needle retraction is finished, the second latch 35 moves upward to the maximum stroke position, and the top end face of the second latch 35 forms a rigid contact and locks with the stop end face 521 at the top of the second elongated groove 52, so that the needle-carrying component 3 cannot continue to move upward.

[0049] Optionally, the outer wall of the needle-type component 3 is provided with a first elongated groove 34 that communicates with and extends axially into the receiving cavity 39. The inner wall of the first elongated groove 34 is provided with a first protrusion 32 that protrudes laterally, forming an obstacle in the path of the push rod 1. The inner wall of the receiving cavity 39 is also provided with a sliding groove 391 located above and aligned with the first elongated groove 34, which guides the first latch 15 of the push rod 1 to slide downward into the first elongated groove 34 during assembly. The sliding groove 391, the first elongated groove 34 and the first latch 15 cooperate to allow the first latch 15 to slide in the sliding groove 391 and the first elongated groove 34. During assembly, the first latch 15 of the push rod 1 first slides downward along the sliding groove 391 in the receiving cavity 39, and then crosses the sliding groove 391 into the first elongated groove 34. Preferably, the first protrusion 32 is provided with an arc surface to facilitate the subsequent downward advancement of the push rod 1.

[0050] Optionally, the top of the first elongated groove 34 is provided with an inner top surface 341 located above the first protrusion 32, and the inner top surface 341 is adapted to the upper end surface of the first latch 15. In this embodiment, when the first latch 15 enters between the first protrusion 32 and the inner top surface 341, any external force attempting to pull the push rod 1 upward along the axial direction will cause the upper end surface of the first latch 15 to adapt to the inner top surface 341, making the upper end surface of the first latch 15 more tightly abut against the inner top surface 341 of the first elongated groove 34. The two form a rigid contact relationship, thereby physically and irreversibly locking the upward movement of the push rod 1.

[0051] Optionally, the bottom of the needle-attached component 3 is provided with a needle fixing end 38 and a drug reservoir fixing end 36 located above the needle fixing end 38. The needle fixing end 38 is used for fixed connection with the needle 7, and the drug reservoir fixing end 36 is used for fixed connection with the drug reservoir 6. The drug reservoir 6 stores solid drug 9, which can be a cylindrical implant. The needle 7 is a hollow cylindrical structure with open ends, one end of which is angled to facilitate skin puncture. The push rod 2 is movably inserted into the drug reservoir 6 and the needle 7. When the implant syringe is in the injection state, the push rod 1 drives the push rod 2 downward, and the push rod 2 pushes the solid drug 9 in the drug reservoir 6 through the needle 7 and injects it into the patient's body.

[0052] In some embodiments, in the initial state, the safety pin 4 is sleeved on the outer wall of the push rod 1 and locked between the push rod 1 and the needle-bearing member 3. The safety pin 4 has a clip-like structure, with a rectangular gripping portion 41 at the top for finger pinching. The bottom of the safety pin 4 has a flange 42 for abutting against the insertion groove 31 of the needle-bearing member 3, so that the safety pin 4 can be fixed on the insertion groove 31. The interior of the safety pin 4 has a buckle 43, which, in the initial state, engages with the groove 13 of the push rod 1 to achieve initial locking of the push rod 1.

[0053] In some embodiments, the housing 5 is a hollow cuboid structure with an axial slide 56 inside for accommodating the needle-bearing member 3, which can slide axially within the slide 56. A first hole 51, a second hole 53, and a third hole 54 are arranged vertically on one side wall of the housing 5. The first hole 51 initially engages with the protruding portion of the first elastic locking member 33 of the needle-bearing member 3, so that the protruding portion of the first elastic locking member 33 is embedded in the first hole 51 initially. The second hole 53 engages with the protruding portion of the second elastic locking member 37 of the needle-bearing member 3 at the end of needle retraction, so that the protruding portion of the second elastic locking member 37 is embedded in the second hole 53 at the end of needle retraction. The third hole 54 initially engages with the protruding portion of the second elastic locking member 37 of the needle-bearing member 3, so that the protruding portion of the second elastic locking member 37 is embedded in the third hole 54 initially.

[0054] Optionally, a second elongated groove 52 extending axially is also provided on the side wall of the housing 5 to accommodate the second latch 35 of the needle-carrying member 3 and allow it to slide. A stop end face 521 is provided at the top of the second elongated groove 52, which abuts against the top end face of the second latch 35 at the end of needle retraction, preventing the needle-carrying member 3 from moving upward. The second hole 53 extends radially and communicates with the second elongated groove 52.

[0055] Optionally, inclined downward-facing slanted holes 57 are provided on both sides of the second hole 53, and an outwardly expandable deformable portion 58 is formed in the area between the slanted holes 57 and the second elongated groove 52. When the needle-carrying member 3 moves upward to retract the needle, the second elastic locking member 37 is supported by the outer wall of the push rod 1 and cannot retract inward to deform. At this time, the deformable portion 58 formed in the area between the slanted holes 57 on both sides of the second hole 53 and the second elongated groove 52 can expand outward to deform, thereby providing space for the second elastic locking member 37 to expand outward to deform, so that the second elastic locking member 37 can move upward smoothly, while ensuring that the force used by the operator when retracting the needle does not change significantly, making the operation convenient.

[0056] Optionally, the housing 5 is also provided with an internal rib 55 that cooperates with the first latch 15 of the push rod 1. At the end of the injection, the first latch 15 of the push rod 1 presses against the top of the internal rib 55 as the end limit of the injection stroke.

[0057] In some embodiments, the drug reservoir 6 is a hollow cylinder with a third elastic locking member 61 on its side wall. The third elastic locking member 61 has an internal protrusion 63 for securing the solid drug 9. This third elastic locking member 61 provides elasticity, allowing the internal protrusion 63 at its end to press inwards against the solid drug 9, thereby securing the solid drug 9 within the drug reservoir 6 and preventing it from falling out. The bottom of the drug reservoir 6 has a fixing part 62, which is used to fixably connect to the fixing end 36 of the drug reservoir with the needle 3.

[0058] In some embodiments, the pen cap 8 is a hollow square shell structure with one open end and the other closed. Its open end is used to fit onto the front end of the shell 5, sealing the needle tip inside its cavity. A protruding first locking point 81 and a second locking point 82 located below the first locking point 81 are provided on the outer side of the open end of the pen cap 8. The first locking point 81 engages with the inner edge of the front end of the shell 5, and the second locking point 82 engages with the outer edge of the front end of the shell 5, so that the pen cap 8 can be stably and firmly held on the shell 5 without being subjected to a subjective pulling force. A second protruding rib 83 is provided on the side wall of the pen cap 8 at a position corresponding to the second elastic locking member 37. This second protruding rib 83 is a slender strip-shaped rib that extends axially a certain length from the open end of the pen cap 8 towards the closed end. Its extension length is configured such that when the pen cap 8 is fitted into place, the second protruding rib 83 can extend into the shell 5 and the interior of the needle-bearing member 3, and support the second elastic locking member 37 of the needle-bearing member 3 from the inside.

[0059] When the implantable syringe is in a non-use state, such as during transportation, storage, or without medication, the pen cap 8 is fully pushed onto the predetermined position at the front end of the housing 5. In this state, the second protruding rib 83 extends precisely into the internal space of the housing 5 and is located precisely on the radially inner side of the second elastic locking member 37. The outer surface of the second protruding rib 83 contacts the inner surface of the second elastic locking member 37 and applies a radially outward rigid supporting force to it. This supporting force presses against the second elastic locking member 37 from the inside, causing it to lose the clearance space for inward elastic deformation, thus preventing the second elastic locking member 37 from retracting inward. As a result, the protruding portion on the outer side of the second elastic locking member 37 is forcibly and irrevocably locked within the third hole 54 of the housing 5, thereby fixing the needle member 3 within the housing 5. Therefore, when the pen cap 8 is not removed, the needle member 3, the drug reservoir 6, the housing 5, and the pen cap 8 form a single integrated structure.

[0060] This rigid locking relationship, formed by the second protruding rib 83 of the pen cap 8, the second elastic locking element 37 of the needle-bearing component 3, and the third hole 54 of the housing 5, firmly locks the needle-bearing component 3 and the housing 5 into a rigid whole. In this locked state, regardless of any misoperational force or transportation vibration, such as an operator accidentally pressing the push rod 1 without removing the pen cap 8, or the syringe being accidentally dropped and impacted, the needle-bearing component 3 cannot undergo any axial displacement relative to the housing 5, and especially cannot retract. This fundamentally eliminates safety hazards such as premature needle tip exposure and accidental drug ejection caused by accidental loosening or retraction of the needle-bearing component 3.

[0061] Therefore, the implantable syringe provided in this application ingeniously upgrades the pen cap 8, an essential packaging and protective component for all syringes, into a removable rigid safety latch. Through the precise coordination of the second protruding rib 83 with corresponding features on the needle-bearing component 3 and the housing 5, a reliable transportation and storage safety locking mechanism is constructed for the syringe at near-zero marginal cost without adding any extra parts or assembly processes. This mechanism makes the operator's natural action of removing the pen cap 8 a prerequisite for disengaging the safety latch. The safety logic is rigorous, the operation process is smooth, and it has extremely high clinical practical value and promising prospects for widespread application.

[0062] The assembly relationship of the implant syringe provided in this application is as follows: First, the fixing part 62 of the drug reservoir tube 6 is fixedly installed on the fixing end 36 of the drug reservoir tube with needle 3, and the needle 7 is fixedly installed on the fixing end 38 of the needle 3. Thus, the drug reservoir tube 6, the needle 7 and the needle 3 are fixedly connected as a whole to form a needle assembly. The push rod 2 is fixedly installed in the center of the push rod 1, and the push rod 2 and the push rod 1 are fixedly connected as a whole to form a push rod assembly.

[0063] Secondly, the needle-carrying component 3 is installed into the axial slide rail 56 of the housing 5. After installation, the needle-carrying component 3 can still move upward.

[0064] Then, push rod 1 is inserted into the receiving cavity 39 of the needle-attached component 3. The first latch 15 of push rod 1 slides down along the groove 391 on the inner wall of the receiving cavity 39, passes over the groove 391 and enters the first elongated groove 34, and is embedded between the first protrusion 32 and the inner top surface 341 of the first elongated groove 34. At this time, the first latch 15 contacts the first protrusion 32, the bottom end of the first latch 15 is restricted by the first protrusion 32, and the top end of the first latch 15 is restricted by the inner top surface 341 of the first elongated groove 34, so that the first latch 15 is embedded between the first protrusion 32 and the inner top surface 341 of the first elongated groove 34, thereby achieving the fixation between push rod 1 and needle-attached component 3. At this time, any external force that attempts to pull push rod 1 upward in the axial direction will only make the upper end surface of the first latch 15 press more tightly against the inner top surface 341 of the first elongated groove 34, and the two form a rigid contact relationship. Thus, the upward movement of push rod 1 is physically and irreversibly locked. This locking is a hard-locking type of anti-reverse fit; unless the structure of push rod 1 or needle-attached component 3 is deliberately damaged, the lock cannot be released, and push rod 1 cannot move upward after installation. At this time, the first elastic locking member 33 of needle-attached component 3 is initially supported from the inside by the first protruding rib 14 on push rod 1, causing its protruding part to embed into the first hole 51 of housing 5, thereby achieving the first locking between needle-attached component 3 and housing 5, preventing needle-attached component 3 from moving upward relative to housing 5 in the initial state. At this point, the needle-attached assembly is fixed.

[0065] The first buckle 15 has a downward-sloping side, which facilitates its sliding from the slide groove 391 into the first elongated groove 34. Since the upper surface of the first buckle 15 is flat, when an external force pulls the push rod 1 upwards axially, this flat surface will form a surface contact with the inner top surface 341 of the first elongated groove 34, causing the first buckle 15 to tightly abut against the inner top surface 341 of the first elongated groove 34. This achieves the fixation between the push rod 1 and the pin-shaped component 3, preventing the push rod 1 from retracting during upward movement.

[0066] Therefore, this application achieves a highly reliable rigid unidirectional drive anti-retraction mechanism using only the first latch 15 of the push rod 1, the first protrusion 32 of the needle-bearing component 3, and the first elongated groove 34. This mechanism automatically establishes the anti-retraction function during assembly with a simple push-in operation, requiring no independent springs, elastic arms, or other third-party parts, resulting in a minimally simplistic structure and extremely low cost. Furthermore, while the anti-retraction lock is established, the needle-bearing component 3 has a first elongated groove 34 to ensure the push rod 1 still has a complete downward injection stroke. When the push rod 1 continues to advance downwards to perform the drug injection action, the first latch 15 slides smoothly downwards along the first elongated groove 34 until it reaches the end of its stroke. The design of this first elongated groove 34 cleverly avoids interference between the first latch 15 and other parts of the inner wall of the needle-bearing component 3 after passing the first protrusion 32, ensuring the smoothness of the injection action.

[0067] Next, the buckle 43 of the safety pin 4 is inserted into the groove 13 of the push rod 1, so that the safety pin 4 is fitted onto the outer wall of the push rod 1 and locked between the push rod 1 and the pin-shaped component 3. Without removing the safety pin 4, the push rod 1 cannot move downward. At this point, the push rod assembly is fixed.

[0068] Finally, the pen cap 8 is fitted onto the front opening of the housing 5, so that the first locking point 81 engages with the inner edge of the front end of the housing 5 and the second locking point 82 engages with the outer edge of the front end of the housing 5. When the pen cap 8 is installed in place, the second protruding rib 83 on its inner wall extends precisely into the interior of the housing 5 and is located precisely on the radially inner side of the second elastic locking member 37 of the pin member 3. It pushes against the second elastic locking member 37 from the inside, so that the protruding part on its outer side is firmly embedded in the third hole 54 of the housing 5, thereby achieving a second locking between the pin member 3 and the housing 5, thus fixing the pin member 3 in the housing 5 in the initial state and preventing it from moving upward.

[0069] The implantable syringe provided in this application sequentially goes through five stages: initial state, injection state, injection end, needle withdrawal state, and needle withdrawal end. The following details the multiple safety mechanisms of this application in conjunction with each stage.

[0070] When the syringe is not in use, is in its initial state such as during transportation or storage, this application provides three independent and redundant safety features to completely lock the core components of the syringe.

[0071] The first safety measure is provided by safety pin 4. In the initial state, the buckle 43 of safety pin 4 is engaged in the groove 13 of push rod 1 and simultaneously abuts against the needle-carrying component 3, physically locking push rod 1 so that neither push rod 1 nor needle-carrying component 3 can move.

[0072] The second safety feature is primarily constructed by the pen cap 8. When the pen cap 8 is properly seated, its second protruding rib 83 extends into the housing 5 and supports the second elastic locking member 37 from the inside. This second protruding rib 83 applies a radially outward rigid support force to the second elastic locking member 37, locking it from the inside and eliminating its space for inward elastic deformation. As a result, the protruding portion on the outer side of the second elastic locking member 37 is forcibly and irrevocably locked within the third hole 54 of the housing 5, thereby fixing the needle member 3 to the housing 5 and preventing any axial displacement. At this point, the needle member 3, the medicine reservoir 6, the housing 5, and the pen cap 8 are fixedly connected as a single, immovable assembly.

[0073] These two safety measures are completely independent in structure and function. Even if the safety pin 4 is accidentally detached during transportation, as long as the pen cap 8 is not pulled out, the needle-carrying component 3 is still firmly locked by the rigid locking relationship formed by the second elastic locking component 37, the third hole 54, and the second protruding rib 83, which fundamentally eliminates the safety hazard of accidental drug ejection or needle tip extension due to transportation vibration or misoperation.

[0074] The third layer of protection is primarily constructed by pusher 1. For example... Figures 2 to 5 As shown, in this initial state, push rod 1 is at the beginning of its stroke, and the first protruding rib 14 on it moves to a position opposite to the first elastic locking member 33, forming a rigid support for the first elastic locking member 33 from the inside, so that the protruding part of the first elastic locking member 33 remains embedded in the first hole 51 of the housing 5. Thus, the first elastic locking member 33 and the first hole 51 constitute another set of parallel mechanical locks. These two sets of locks—namely, the lock of the second elastic locking member 37 and the third hole 54 dominated by the pen cap 8, and the lock of the first elastic locking member 33 and the first hole 51 dominated by the push rod 1—are structurally independent and functionally independent, and together they constitute a redundant double insurance mechanism. Even if the safety pin 4 is accidentally dislodged during transportation, as long as the pen cap 8 is not pulled out, the front and rear displacement channel of the needle member 3 is still completely blocked, and the safety level is significantly higher than that of the traditional single locking scheme.

[0075] When an injection procedure is required, the operator shall follow these steps.

[0076] First, remove the safety pin 4 and the pen cap 8. Pull the safety pin 4 outward to release the first locking mechanism on the push rod 1, allowing the push rod 1 to move downward, while the needle-carrying component 3 cannot move upward. Pinch the pen cap 8 and pull it outward axially, disengaging the first locking point 81 and the second locking point 82 of the pen cap 8 from the front end of the housing 5. As the pen cap 8 is removed, the second protruding rib 83 simultaneously exits axially from inside the housing 5, instantly removing its rigid support force on the second elastic locking component 37. After the support force is removed, the second elastic locking component 37 regains its inherent elastic deformation capability. At this time, although its protruding part is still embedded in the third hole 54 of the housing 5, due to the loss of the inner rigid support, it can elastically retract inward once subjected to a sufficiently large axial thrust, thereby allowing the needle-carrying component 3 to move axially relative to the housing 5. Therefore, removing the pen cap 8 not only completes the routine task of removing the needle tip protection, but also automatically removes the second layer of protection for controlling the pen cap 8, without adding any extra steps.

[0077] At this point, the first elastic locking element 33 is still supported by the first protruding rib 14 of the push rod 1, and the axial movement of the needle-carrying element 3 has not been fully released. The second elastic locking element 37 is in a "partially ready" state, which is released but the first elastic locking element 33 is still locked. Only when the subsequent injection action pushes the push rod 1 to the predetermined depth, causing the first protruding rib 14 to misalign with the first elastic locking element 33, and the first elastic locking element 33 also gains room to retract inward, is the needle-carrying element 3 fully unlocked, allowing it to smoothly retract and complete the needle withdrawal action. This step-by-step unlocking logic ensures that the sequence of "inject first, then withdraw needle" cannot be reversed, reflecting the rigorous safety design of the instrument.

[0078] The second step is to puncture and press the plunger 1 to administer the injection. The operator inserts the needle 7 into the patient's skin and then presses down on the top plate 11 of the plunger 1 to begin the injection.

[0079] At the instant the push rod 1 begins to move downwards, the first latch 15 slides downwards along the first elongated groove 34 and passes over the first protrusion 32. Because the surface of the first protrusion 32 is arc-shaped, the first latch 15 can smoothly pass over this obstacle. Throughout the downward movement of the push rod 1, the first protruding rib 14 on the side wall of the push rod 1 always supports the first elastic locking member 33 on the needle-carrying component 3 from the inside, keeping its protruding portion embedded in the first hole 51 of the housing 5. This means that throughout the entire injection process, the needle-carrying component 3 is forcibly locked in the extended position and cannot be retracted upwards into the housing 5. Therefore, this invention mechanically enforces the correct operating sequence of "injection must be completed before unlocking and retracting the needle," completely eliminating the serious failure mode of "retracting the needle before injection" caused by operational errors.

[0080] As the push rod 1 continues to descend, the push rod 2 pushes the solid drug 9 in the drug reservoir 6, pushing the solid drug 9 into the patient's subcutaneous tissue through the needle 7. When the push rod 1 moves downward until its first latch 15 presses against the top of the internal rib 55 of the housing 5, the push rod 1 can no longer descend, indicating that the solid drug 9 has been completely ejected and the injection phase is over.

[0081] At the end of the injection, a crucial unlocking condition is automatically triggered: the groove 13 on the side wall of the push rod 1 moves precisely to a position horizontally aligned with the first elastic locking member 33 on the needle-carrying component 3. The presence of the groove 13 provides inward retraction space for the first elastic locking member 33, allowing the needle-carrying component 3 to move upward and complete needle retraction. Therefore, the upward retraction path of the needle-carrying component 3 can only be unlocked when the injection is completely completed and the push rod 1 reaches its lowest point of travel. This design mechanically ensures a mandatory timing relationship between the injection and needle retraction actions.

[0082] After the injection is completed, the operator pulls the needle-carrying component 3 upwards to withdraw the needle.

[0083] Since the groove 13 has provided clearance, the first elastic locking member 33 of the pin member 3, under the action of axial tension, is squeezed inward by the edge of the first hole 51 of the housing 5 and its protruding part is dislodged from the first hole 51. The pin member 3 is thus unlocked, which can drive the pin 7 to retract upward into the housing 5.

[0084] Meanwhile, since the support (pen cap 8) of the second elastic locking member 37 has been removed and it is elastic, it can adaptively pass through the inner wall of the housing 5 during the needle retraction process.

[0085] When the needle-carrying component 3 moves upward to the limit position where the needle retraction ends, a high-strength, irreversible double-interlock final state locking mechanism is triggered, permanently locking the syringe into a safe discard state.

[0086] First locking mechanism: interference interlock between push rod 1 and needle-carrying component 3.

[0087] As the needle-carrying component 3 moves upward to the end of its retraction phase, the top plate 11 of the push rod 1 is fully pressed into and embedded in the insertion groove 31 at the top of the needle-carrying component 3. The protruding ribs 12 on the sides of the top plate 11 interfere with the inner wall of the insertion groove 31, forming a tight interference fit. This interference fit generates a strong radial clamping force, firmly locking the push rod 1 onto the needle-carrying component 3, thus locking the push rod 1 and the needle-carrying component 3 into an inseparable whole. The push rod 1 can no longer be pushed downward or pulled upward. With the top plate 11 completely submerged in the insertion groove 31, the push rod 1 has no exposed operating end, further enhancing its anti-reuse capability.

[0088] Second layer of locking: multi-feature deadlock between pin 3 and housing 5.

[0089] As the first locking is established, the second buckle 35 on the pin 3 slides along the second long groove 52 of the housing 5 to the uppermost end of its travel. The top end face of the second buckle 35 forms a rigid surface contact with the stop end face 521 at the top of the second long groove 52, locking the upward movement path of the pin 3.

[0090] At the same time, the second elastic locking member 37 on the needle member 3 moves to the position corresponding to the second hole 53 of the housing 5. At this moment, the first protruding rib 14 on the push rod 1 is exactly in the position of supporting the second elastic locking member 37 from the inside, so that the second elastic locking member 37 cannot retract inward, and its protruding part is forced to be embedded in the second hole 53, locking the downward movement path of the needle member 3.

[0091] At this point, the needle-carrying component 3 is locked in the upward direction by the cooperation of the second buckle 35 and the stop end face 521, and in the downward direction by the cooperation of the second elastic locking component 37 and the second hole 53, thus completely locking its entire axial movement path.

[0092] Thus, the first layer of locking binds the push rod 1 and the needle-carrying component 3 into an inseparable whole, while the second layer of locking completely locks this interlocked whole along the axial direction of the housing 5. The push rod 1 cannot be pushed forward or pulled out, the needle-carrying component 3 cannot move upward or downward, and the needle 7 is permanently and securely sealed inside the housing 5. This fundamentally eliminates the risk of the push rod 1 dislodging or the needle accidentally re-extending due to external impact or deliberate prying, significantly improving the final safety of disposable injection devices. Compared to traditional solutions that only lock a single component or rely solely on a single locking feature, this dual-coordinated locking method substantially improves locking strength and resistance to impact damage.

[0093] Another advantage of this application is its simple and efficient assembly process. During assembly, the push rod 1 is aligned with the top opening of the pin-shaped part 3 and pushed downwards axially. The first latch 15 of the push rod 1 slides downwards along the groove 391 on the inner wall of the receiving cavity 39. Since the side of the first latch 15 has a downward-sloping inclined surface 151, it can smoothly transition from the groove 391 into the first long groove 34. Under the action of the pushing force, the first latch 15 forcibly squeezes past the first protrusion 32, thus automatically achieving the aforementioned one-way anti-retraction function. The entire assembly process is a one-step push-in operation, without the need for additional locking assembly steps, resulting in high assembly efficiency.

[0094] In summary, the implantable syringe provided in this application ingeniously achieves a complete safety closed loop throughout the entire process, from double insurance during transportation, unidirectional drive anti-reverse mechanism, forced sequential injection, to final-state double irreversible interlocking, by utilizing only the integrally molded structure of each component body without adding any independent springs, locking pins, or other third-party parts. Its simplified structure, rigorous logic, and high reliability significantly improve the safety of implantable syringes in all stages of transportation, operation, and disposal.

[0095] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An implantable syringe, characterized in that, include: The housing (5) has a first hole (51) and a third hole (54) on its side wall. The pin member (3) is slidably accommodated in the housing (5), and its sidewall is provided with a first elastic locking member (33) and a second elastic locking member (37) protruding outward. The push rod (1) is inserted into the needle-loaded part (3), and its side wall is provided with a first protruding rib (14). The pen cap (8) is detachably fitted onto the front end of the housing (5), and its side wall is provided with a second protruding rib (83). In the initial state, the pen cap (8) is fitted onto the housing (5), the second protruding rib (83) pushes against the second elastic locking member (37) from the inside, so that the protruding part of the second elastic locking member (37) is embedded in the third hole (54); and the first protruding rib (14) pushes against the first elastic locking member (33) from the inside, so that the protruding part of the first elastic locking member (33) is embedded in the first hole (51); so as to lock the pin member (3) onto the housing (5).

2. The implantation syringe according to claim 1, characterized in that, The push rod (1) has a groove (13) on its side wall. The groove (13) is configured such that when the push rod (1) moves downward to the injection end position, the groove (13) aligns with the first elastic locking member (33) to provide the first elastic locking member (33) with an inward retraction clearance space to allow the needle member (3) to move upward relative to the housing (5).

3. The implantation syringe according to claim 1, characterized in that, The side wall of the housing (5) is also provided with a second elongated groove (52) extending along the axial direction and a second hole (53) communicating with the second elongated groove (52); the side wall of the pin-shaped component (3) is also provided with a second buckle (35). When the needle retraction ends, the second buckle (35) slides to the top of the second long groove (52) and abuts against the stop end face (521) provided at the top of the second long groove (52); and the first protruding rib (14) of the push rod (1) pushes the second elastic locking member (37) from the inside, so that its protruding part is embedded in the second hole (53); to lock the needle member (3) and the housing (5).

4. The implantation syringe according to claim 3, characterized in that, The second hole (53) is provided with oblique strip holes (57) on both sides, and the area between the oblique strip holes (57) and the second long groove (52) forms an outwardly expandable deformable part (58).

5. The implantation syringe according to claim 1, characterized in that, The needle-bearing component (3) has an axially extending receiving cavity (39) inside, and the wall of the needle-bearing component (3) has a first long groove (34) that communicates with the receiving cavity (39) and extends axially. The inner wall of the first long groove (34) has a first protrusion (32); the outer wall of the push rod (1) has a first buckle (15). The first latch (15) is configured to slide along the first long groove (34) and pass the first protrusion (32) downward when the push rod (1) is pushed downward in the axial direction; when the push rod (1) is subjected to an external force in the axial direction, the upper end face of the first latch (15) abuts against the inner top surface (341) of the first long groove (34) to restrict the upward movement of the push rod (1).

6. The implantation syringe according to claim 5, characterized in that, The inner wall of the receiving cavity (39) is also provided with a sliding groove (391) located above and aligned with the first long groove (34) for guiding the first buckle (15) to slide down into the first long groove (34).

7. The implantation syringe according to claim 1, characterized in that, The top of the needle-type component (3) is provided with an embedding groove (31); the top of the push rod (1) is provided with a top plate (11), and the side of the top plate (11) is provided with outwardly protruding ribs (12). When the needle retraction is finished, the top plate (11) is embedded in the embedding groove (31), and the rib (12) forms an interference fit with the inner wall of the embedding groove (31) to lock the push rod (1) and the needle-carrying part (3).

8. The implantation syringe according to claim 2, characterized in that, It also includes a safety pin (4), which has a buckle (43); in the initial state, the safety pin (4) is sleeved on the outer wall of the push rod (1) and abuts against the needle-carrying member (3), and the buckle (43) is inserted into the groove (13) on the side wall of the push rod (1) to lock the push rod (1) to the needle-carrying member (3).

9. The implantable syringe according to claim 1, characterized in that, The bottom of the needle-bearing component (3) is fixedly connected to a needle (7) and a drug reservoir (6); the drug reservoir (6) stores a solid drug (9), and the side wall of the drug reservoir (6) is provided with a third elastic locking member (61), and the interior of the third elastic locking member (61) is provided with an internal protrusion (63) for fixing the solid drug (9); a push rod (2) is fixedly installed inside the push rod (1), and the push rod (2) is movably inserted into the drug reservoir (6) and the needle (7).

10. The implantation syringe according to claim 5, characterized in that, The housing (5) is also provided with an internal rib (55); at the end of the injection, the first buckle (15) presses against the top of the internal rib (55) to limit the injection stroke of the push rod (1).

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