An automatic injection pen

Abstract

The present application relates to a kind of automatic injection pen, including injection pen body, the injection front end of injection pen body is movably provided with pen cap, injection pen body includes shell, observation window is provided on shell, inner shell device is arranged in shell, PFS device is arranged in the inside of inner shell device, the rear end of inner shell device is provided with propelling device.Propelling device has disable function, so that, when injection is finished, effective injection single time limit can be realized, when user wants to carry out secondary injection, make secondary injection terminate, avoid the reuse of automatic injector, improve injection safety.Propelling device is equipped with sound production component, can generate a more obvious "latch" prompt sound by the collision, friction with push rod component when injection is finished, user does not need to stare at the injection condition of drug solution in observation window, also can know that injection is finished.

Description

TECHNICAL FIELD

[0001] The present application relates to an injection pen, in particular to an automatic injection pen. BACKGROUND

[0002] The existing disposable automatic injection device has a very complex design principle, resulting in a large number of components, generally more than 15, so the reliability is not high, the assembly is difficult, and the final product cost is too high.

[0003] CN110237366A discloses a medical injection device, which comprises an outer cylinder and a cap, one end of the outer cylinder is provided with a detachable medicine bin, a replaceable standard cassette medicine bottle is arranged in the medicine bin, a fixed sleeve is arranged at one end of the inner part of the outer cylinder, a push rod seat is arranged in the inner part of the fixed sleeve and moves axially, a transmission ring is arranged in the inner part of the push rod seat and can engage with the end of the transmission rod, a ratchet ring is sleeved on the outer side of the transmission rod and can slide axially, the end face of one end of the ratchet ring is in one-way engagement with the inner part of the outer cylinder, a first spring is arranged at the other end of the ratchet ring, a push rod seat spring is arranged at one end of the push rod seat and abuts against the outer cylinder, and one end of the push rod extends into the standard cassette medicine bottle and is connected with a push block.

[0004] CN109999272A discloses a disposable adjustable injection device for insulin injection, which comprises a protective cover, a disposable needle, a cartridge sleeve, a main body shell, a cartridge and an adjusting assembly, one end of the main body shell is provided with a second boss, the outer part of the second boss is provided with a cartridge sleeve, one end of the cartridge sleeve is provided with a threaded groove, the outer thread of the second boss is screwed with the threaded groove, the other end of the cartridge sleeve is provided with a first boss, the outer part of the first boss is connected with a disposable needle through a thread, the inner part of the disposable needle is inserted with a steel needle, the inner part of the cartridge sleeve is installed with a cartridge, the outer part of the cartridge sleeve is sleeved with a protective cover, the other end of the main body shell is provided with an adjusting assembly, the inner part of the main body shell is installed with a fixed sleeve, and the one end of the fixed sleeve protrudes outwardly with a flange part.

[0005] CN102264417A discloses an injection device comprising a long housing, a container carrier with a medicament container, a needle mounted to the medicament container, a puncture device comprising a separate sleeve, a preloaded puncture spring device and a puncture holding device, wherein the preloaded puncture spring device is able to act on the separate sleeve and thereby on the container carrier to cause a sliding movement of the container and the needle, and the puncture holding device is able to hold the puncture spring device in a loaded state, an injection device comprising a plunger rod, a preloaded injection spring device and an injection holding device, wherein the plunger rod is arranged to act on a stopper in the medicament container, the preloaded injection spring device is able to act on the plunger rod so that the stopper is displaced within the container, and the injection holding device is able to hold the injection spring device in a loaded state, a retraction device comprising a preloaded retraction spring and a retraction holding device, wherein the preloaded retraction spring is arranged to act on the separate sleeve and thereby on the container carrier, and the retraction holding device is able to hold the retraction spring in a loaded state, a puncture sequence initiation device able to act on a puncture trigger device arranged on the separate sleeve for disengaging the puncture holding device, an injection trigger device arranged on the separate sleeve and able to disengage the injection holding device for initiating an injection sequence when the separate sleeve and the plunger rod have moved to a certain position, and a retraction trigger device arranged on the separate sleeve and able to disengage the retraction holding device for initiating a needle retraction when the plunger rod has moved to a certain position, characterized in that the device further comprises a damping device comprising a compartment containing a volume of a highly viscous liquid and being partially defined by an outer surface of the plunger rod and an inner surface of a cap, wherein the compartment is arranged with a passage through which the liquid is forced only at initiation of the injection sequence so that the volume within the compartment decreases during the entire injection sequence with the movement of the plunger rod in the container and thereby a damping shear force is generated.

[0006] In view of the above-mentioned defects, the present inventor has actively made research and innovation, so as to create an automatic injection pen, which has more industrial utilization value. SUMMARY

[0007] To solve the above technical problems, the purpose of the present application is to provide an automatic injection pen.

[0008] The application discloses an automatic injection pen, which comprises a pen body, and a cap movably arranged at the front end of the pen body, wherein the pen body comprises a shell, an observation window is arranged on the shell, an inner shell device is arranged in the shell, a propelling device is arranged at the rear end of the inner shell device, a sound emitting component is arranged on the propelling device, the inner shell device comprises an inner shell body, an inner sleeve component is arranged at the front end of the inner shell body, a PFS device is arranged in the inner sleeve component, the propelling device comprises an upper main shaft, a lower main shaft is sleeved on the upper main shaft, a push rod component is arranged in the lower main shaft, a main spring is arranged between the push rod component and the upper main shaft, a sliding block component is sleeved on the lower main shaft, a secondary spring is arranged between the lower main shaft and the sliding block component, and the sound emitting component is arranged at the front end of the lower main shaft.

[0009] Further, the automatic injection pen, wherein the tail end of the inner sleeve component is provided with a buffer component, and the buffer component is a silica gel pad.

[0010] Further, the automatic injection pen, wherein a guide groove is formed in the inner shell body, a locking block is arranged on the inner sleeve component, and a limiting protrusion is further arranged on the outer side of the inner sleeve component.

[0011] Further, the automatic injection pen, wherein the lower main shaft comprises a lower shaft cavity, a pair of guide front flaps are arranged at the front end of the lower shaft cavity, a stop protrusion is arranged on the guide front flap, a locking protrusion is arranged at the middle part of the lower shaft cavity, a one-way guide protrusion is arranged at the rear end of the lower shaft cavity, and an axial guide slope is arranged on the one-way guide protrusion.

[0012] Further, the automatic injection pen, wherein the upper main shaft comprises a shaft base, an upper shaft rod is arranged on the shaft base, and a main spring is sleeved on the upper shaft rod.

[0013] Further, the automatic injection pen, wherein the push rod component comprises a push rod body, a reserved groove is arranged at the front end of the push rod body, a clamping groove is arranged at the middle segment of the push rod body, a trigger groove is arranged at the tail end of the push rod body, and the sound emitting component contacts the trigger groove when the injection is about to be completed.

[0014] Further, the automatic injection pen, wherein the sliding block component comprises a sliding block body, a plurality of reinforcing ribs are arranged on the outer wall of the sliding block body, and a plurality of guide grooves are arranged on the inner wall of the sliding block body.

[0015] Further, the automatic injection pen, wherein the PFS device comprises a PFS body, a needle protection cover is arranged at the injection end of the PFS body, a plunger is arranged in the tail end of the PFS body, and the plunger is a silica gel plug.

[0016] Further, the automatic injection pen, wherein the sound generating component comprises a sound generating block, and the sound generating block is internally provided with an energy storage block.

[0017] Further, the automatic injection pen, wherein the inner sleeve component comprises an inner sleeve body, and the tail section of the inner sleeve body is externally provided with a locking protrusion.

[0018] By the above scheme, the present application has at least the following advantages:

[0019] 1. Relying on the mutual cooperation of the sliding block component and the inner shell device, when the injection is completed, the effective injection single-time limiting can be realized, when the user wants to perform secondary injection, the sliding block component can be limited, so that the secondary injection is terminated, the repeated use of the automatic injection device is avoided, and the injection safety is improved.

[0020] 2. The sound generating component is configured, which can generate a relatively obvious "clamping position" prompt sound through the collision and friction with the push rod component when the injection is completed, the user does not need to stare at the injection situation of the medicine liquid in the observation window, and also can know that the injection is completed. At the same time, the injection area can be avoided to be excessively squeezed.

[0021] 3. The buffer component is composed of silica gel pads, which can limit the subsequent installation of the PFS device, and ensure the smooth work of the PFS device during injection.

[0022] 4. The overall structure is simple, convenient to manufacture and assemble, and convenient to use.

[0023] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, and can be implemented according to the content of the specification, the following is the preferred embodiment of the present application and the detailed description of the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is the exploded structure schematic view of the automatic injection pen.

[0025] Figure 2 is the structure schematic view of the inner shell device.

[0026] Figure 3 is the structure schematic view of the inner sleeve component.

[0027] Figure 4 is the structure schematic view of the lower main shaft.

[0028] Figure 5 is the structure schematic view of the upper main shaft.

[0029] Figure 6 is the structure schematic view of the sliding block component.

[0030] Figure 7 is a structural diagram of the sound emitting assembly.

[0031] Figure 8 is a structural diagram of the assembled propulsion device.

[0032] Figure 9 is a structural diagram of the overall profile of the automatic injection pen.

[0033] Figure 10 is a structural diagram of the automatic injection pen during the injection starting stage.

[0034] Figure 11 is a structural diagram of the automatic injection pen during the puncture stage.

[0035] Figure 12 is a structural diagram of the automatic injection pen during the injection stage.

[0036] Figure 13 is a structural diagram of the automatic injection pen during the reset stage.

[0037] The meanings of the reference numerals in the drawings are as follows.

[0038] 1 upper main shaft 2 lower main shaft

[0039] 3 slider assembly 4 push rod assembly

[0040] 5 sound emitting assembly 6 pen cap

[0041] 7 outer shell 8 buffer assembly

[0042] 9 inner shell device 10 inner sleeve assembly

[0043] 11 needle head protection cover 12 PFS body

[0044] 13 plunger 14 observation window

[0045] 15 main spring 16 secondary spring

[0046] 17 one-way guide bump 18 locking bump

[0047] 19 stop bump 20 clamping groove

[0048] 21 reserved groove 22 trigger groove

[0049] 23 reinforcing rib 24 guide groove

[0050] 25 locking block 26 guide groove

[0051] 27 energy storage block 28 limiting protrusion DETAILED DESCRIPTION

[0052] The specific embodiments of the present application will be further described in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but not to limit the scope of the present application.

[0053] As Figures 1 to 13 An automatic injection pen, comprising a pen body, a cap 6 is movably arranged at the front end of the pen body, and the difference is that the pen body comprises a shell 7, and the shell 7 is provided with an observation window 14. At the same time, the shell 7 is provided with an inner shell device 9. Specifically, the inner shell device 9 comprises an inner shell body, and an inner sleeve assembly 10 is mounted at the front end of the inner shell body. In order to facilitate injection administration, the inner sleeve assembly 10 is provided with a PFS device. And considering the need of injection propulsion, the rear end of the inner shell device 9 is provided with a propulsion device with a disabling function. In order to facilitate the user to give the necessary injection completion prompt, the propulsion device is provided with a sound emitting assembly 5. Relying on the existence of the sound emitting assembly 5, the user can be given appropriate sound prompt after injection. In combination with actual use, considering the smooth progress of the liquid medicine during use, the propulsion device comprises an upper main shaft 1, the lower main shaft 2 is sleeved on the upper main shaft 1, the push rod assembly 4 is arranged in the lower main shaft 2, and the main spring 15 is arranged between the push rod assembly 4 and the upper main shaft 1. Further, the lower main shaft 2 is sleeved with a sliding block assembly 3, the secondary spring 16 is arranged between the lower main shaft 2 and the sliding block assembly 3, and the sound emitting assembly 5 is arranged at the front end of the lower main shaft 2. The secondary spring 16 has two functions. First: provide starting force, so that the user needs to provide a certain force before injection, reduce the possibility of accidental triggering. Second: push the sliding block assembly 3 and the inner shell device 9 out after injection, so that the needle carried on the PFS body 12 does not expose to the inner shell device 9. In actual use, only after the sliding block assembly 3 is pushed through the one-way guide bump 17 of the lower main shaft 2, the disabling function can be triggered.

[0054] In combination with a preferred embodiment of the present application, in order to achieve better accommodation of the PFS device after installation, and to ensure the stable combination of the PFS assembly and the inner sleeve assembly 10, and to prevent unnecessary shaking due to tolerances, the tail end of the inner sleeve assembly 10 is provided with a buffer assembly 8. Relying on the presence of the buffer assembly 8, the buffer protection of the PFS assembly can be effectively achieved, and the appropriate fixing effect can also be achieved, eliminating the gap caused by the assembly tolerance. At the same time, in order to achieve effective contact limiting and not to affect the necessary relative movement of each component during subsequent use, the buffer assembly 8 adopted by the present application is a silica gel pad. In order to achieve necessary movement guidance and control, a guide groove 26 is formed on the inner shell body, and a locking block 25 is provided on the inner sleeve assembly 10. In this way, after the injection is completed, the outer movement of the inner sleeve assembly 10 can be limited by the presence of the locking block 25. And a limiting protrusion 28 is also provided on the outside of the inner sleeve assembly, which can limit the rear movement of the inner shell device 9 when it is in the original state of non-injection, avoiding unnecessary shaking.

[0055] Further, in order to smoothly guide the forward movement of the plunger 13 inside the PFS device, and cooperate with the subsequent sound generating assembly 5, the lower main shaft 2 adopted by the present application includes a lower shaft cavity, and a pair of guide front flaps are distributed at the front end of the lower shaft cavity, and a stop protrusion 19 is provided on the guide front flap. At the same time, a locking protrusion 18 is arranged at the middle part of the lower shaft cavity, and a one-way guide protrusion 17 is arranged at the rear end of the lower shaft cavity, and an axial guide slope is arranged on the one-way guide protrusion 17.

[0056] In combination with the actual implementation, the upper main shaft 1 includes a shaft base, and an upper shaft rod is arranged on the shaft base, and a main spring 15 is sleeved on the upper shaft rod. At the same time, the push rod assembly 4 includes a push rod body, and a reserved slot 21 is arranged at the front end of the push rod body. In this way, in the unused state, the energy storage block 27 of the sound generating assembly is in a natural state rather than a bent state before sound generation, preventing the function from being disabled due to long-term storage. A clamping groove 20 is arranged at the middle segment of the push rod body, and a trigger groove 22 is arranged at the tail end of the push rod body. In the non-injection stage, the clamping groove 20 is combined with the locking protrusion 18 arranged at the middle part of the lower shaft cavity. When the injection is about to be completed, the sound generating assembly 5 contacts the trigger groove 22.

[0057] At the same time, the sliding block assembly 3 includes a sliding block body, and a plurality of reinforcing ribs 23 are distributed on the outer wall of the sliding block body, and a plurality of guide grooves 24 are distributed on the inner wall of the sliding block body. During use, the guide grooves 24 limit the radial deviation of the locking protrusion 18 on one hand, and the tail end of the guide groove is not formed into a step, and cooperates with the one-way guide protrusion 17 and the push rod to prevent the sliding block 3 from moving to the left before injection, and to limit the position after injection, preventing the guide protrusion 17 from re-entering the inside of the sliding block 3.

[0058] Furthermore, the PFS device includes a PFS body 12, with a needle protection cover 11 at the injection end of the PFS body 12, and a plunger 13, which is a silicone plug, inside the tail end of the PFS body 12. The sound-generating component 5 includes a sound-generating block, and an energy storage block 27 is installed inside the sound-generating block. Meanwhile, the inner sleeve component 10 includes an inner sleeve body, with a locking protrusion 18 extending outward from the tail end of the inner sleeve body.

[0059] The working principle of this invention is as follows:

[0060] Step 1: Startup Phase.

[0061] like Figure 10 As shown, remove the pen cap, place the syringe tip with the inner shell device 9 on the skin to be injected, and apply downward pressure.

[0062] Step 2: Puncture stage.

[0063] like Figure 11 As shown, after a brief idle stroke, the inner shell device 9 begins to push the slider assembly 3 upward relative to the needle until the needle contacts the skin. At this point, pressure continues to be applied. The needle begins to puncture the skin, and the inner shell device 9 continues to push the slider assembly 3 upward until the inner shell device 9 reaches its limit position. At this point, the predetermined subcutaneous puncture depth is reached, and the puncture ends. During the implementation of this invention, the limit position mainly refers to the inner shell device 9 protruding from the outer shell 7, but not completely entering the outer shell 7.

[0064] Specifically, during the puncture process, the lower end of the slider assembly 3 moves onto the locking protrusion 18. As a result, due to the loss of the limiting effect of the slider assembly 3, the locking protrusion 18 and the slot 20, which were originally locked, are released from each other. Subsequently, under the thrust of the main spring 15, the slider slides along the axial slope, and the locking protrusion 18 elastically deforms outward until the slot 20 of the push rod assembly 4 completely disengages from the locking protrusion 18. At this point, the main spring 15 pushes the push rod assembly 4 forward.

[0065] Then, the push rod assembly 4 supports the energy storage block 27 of the sound-generating assembly 5. The sound-generating assembly 5 is driven to move and stops moving after hitting the stop protrusion 19 of the lower main shaft 2.

[0066] Finally, the front part of the push rod assembly 4 contacts and abuts against the plunger 13 inside the PFS body 12.

[0067] Step 3: Injection stage.

[0068] like Figure 12As shown, the PFS body 12 and the inner sleeve assembly 10 are engaged and fixed in place. At this time, the main spring 15 continues to push the push rod assembly 4 and the plunger 13, injecting the drug in the PFS body 12 into the patient's subcutaneous tissue until the plunger 13 reaches the bottom of the PFS body 12, at which point the injection ends.

[0069] As the injection nears completion, the energy storage block of the sound-generating component 5 enters the trigger slot 22 of the push rod assembly 4, causing the sound-generating component 5 to collide with the push rod assembly 4 and emit an injection completion alert sound. This completes the injection. This avoids the need for the user to constantly monitor the observation window 14 to know the current injection progress. Furthermore, it prevents unnecessary pressure and damage to the injection area caused by the user excessively pressing the auto-injector due to uncertainty about whether the injection is complete. Simultaneously, it eliminates the need for waiting for confirmation after injection, providing a clearer indication.

[0070] Step 4: Reset phase.

[0071] like Figure 13 As shown, the auto-injector is removed from the injection area. At this time, the secondary spring 16 pushes the slider assembly 3 and the inner shell device 9 backward. When the upper end of the slider assembly 3 contacts the one-way guide protrusion 17, the upper end of the slider assembly 3 slides along the axial guide slope of the one-way guide protrusion 17. Then, the one-way guide protrusion 17 elastically deforms inward, subsequently disengages from the slider assembly 3, and returns to its original shape. At this time, the upper end of the guide groove of the inner shell device 9 abuts against the locking block 25 of the inner sleeve assembly, ending the injection process. In the current state, the one-way guide protrusion 17 has disengaged from the slider assembly 3 and is enclosed within the outer shell 7. Since the one-way guide protrusion 17 cannot re-enter the slider assembly 3 in reverse, if the injector repeats step one, the entire injection process will be blocked, preventing the auto-injector from being reused.

[0072] As can be seen from the above description and the accompanying drawings, the present invention has the following advantages:

[0073] 1. By relying on the cooperation between the slider assembly and the inner shell device, the propulsion device has a disable function. After the injection is completed, it can effectively limit the single injection. When the user wants to perform a second injection, the slider assembly can be limited to stop the second injection, thus avoiding the reuse of the automatic injector and improving injection safety.

[0074] 2. Equipped with a sound-generating component, it produces a noticeable "locking" sound upon completion of injection through collision and friction with the push rod assembly. Users can know the injection is complete without needing to constantly monitor the injection status in the observation window. This also prevents excessive pressure on the injection area.

[0075] 3. The buffer assembly is formed by silica gel pad, which can limit the PFS device installed subsequently while meeting the combination of the PFS assembly and the inner sleeve assembly, and ensure the smooth work of the PFS device during injection.

[0076] 4. The whole structure is simple, convenient to manufacture and assemble, and convenient to use.

[0077] In addition, the indicated orientation or positional relationship described in the present application is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or structure indicated must have a specific orientation or be operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0078] The terms "main" and "secondary" are only for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "main" and "secondary" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "several" is two or more than two, unless otherwise explicitly and specifically limited.

[0079] Similarly, the terms "first" and "second" are only for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "several" is two or more than two, unless otherwise explicitly and specifically limited.

[0080] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "arrangement" and the like should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrated; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two components or the interaction relationship between two components. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. And it can be directly on another component or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly connected to another component or indirectly connected to another component.

[0081] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like specify relative or directional relationships based on the orientations or positions shown in the drawings, are used only to facilitate the description of the application and simplification of description, and do not indicate or imply that the devices or components referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0082] The above description is only the preferred embodiments of the present application and is not intended to limit the present application. It should be pointed out that for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be considered as the protection scope of the present application.

Claims

1. An auto-injector pen comprising a pen body, a pen cap being movably arranged at a front end of the pen body, characterized in that: The injection pen body comprises a shell, an observation window is arranged on the shell, an inner shell device is arranged in the shell, a propelling device is arranged at the rear end of the inner shell device, a sound emitting assembly is arranged on the propelling device, the inner shell device comprises an inner shell body, an inner sleeve assembly is mounted at the front end of the inner shell body, a PFS device is arranged in the inner sleeve assembly, the propelling device comprises an upper main shaft, a lower main shaft is sleeved on the upper main shaft, a push rod assembly is arranged in the lower main shaft, a main spring is arranged between the push rod assembly and the upper main shaft, a sliding block assembly is sleeved on the lower main shaft, a secondary spring is arranged between the lower main shaft and the sliding block assembly, and a sound emitting assembly is arranged at the front end of the lower main shaft; The secondary spring has the following effects:

1. providing starting force, so that the user needs to provide force before injection, reducing the possibility of accidental triggering; 2. pushing the sliding block assembly and the inner shell device out after injection, so that the needle on the PFS body does not expose out of the inner shell device; A buffer assembly is arranged at the tail end of the inner sleeve assembly, the buffer assembly is a silica gel pad, a guide groove is formed in the inner shell body, a locking block is arranged on the inner sleeve assembly, and a limiting protrusion is further arranged on the outer side of the inner sleeve assembly; The lower main shaft comprises a lower shaft cavity, a pair of guide front flaps are arranged at the front end of the lower shaft cavity, a stop protrusion is arranged on the guide front flap, a locking protrusion is arranged at the middle part of the lower shaft cavity, a one-way guide protrusion is arranged at the rear end of the lower shaft cavity, and an axial guide slope is arranged on the one-way guide protrusion; The upper main shaft comprises a shaft base, an upper shaft rod is arranged on the shaft base, and a main spring is sleeved on the upper shaft rod; the push rod assembly comprises a push rod body, a reserved groove is arranged at the front end of the push rod body, a clamping groove is arranged at the middle part of the push rod body, and a trigger groove is arranged at the tail end of the push rod body; when the injection is about to end, the sound emitting assembly contacts the trigger groove; The sliding block assembly comprises a sliding block body, a plurality of reinforcing ribs are arranged on the outer wall of the sliding block body, and a plurality of guide grooves are arranged on the inner wall of the sliding block body; The guide groove limits the radial deviation of the locking protrusion, and the tail end of the guide groove does not penetrate to form a step, cooperates with the one-way guide protrusion and the push rod, prevents the sliding block from moving to the left before injection, and limits the position after injection, preventing the guide protrusion from re-entering the sliding block; The PFS device comprises a PFS body, a needle protection cover is arranged at the injection end of the PFS body, a plunger is arranged in the tail end of the PFS body, and the plunger is a silica gel plug; the sound emitting assembly comprises a sound emitting block, and an energy storage block is arranged in the sound emitting block; in the unused state, the energy storage block of the sound emitting assembly is in a natural state rather than a curved state before sounding; The inner sleeve assembly comprises an inner sleeve body, and a locking protrusion is arranged outwardly at the tail section of the inner sleeve body.

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