Injection auxiliary device and safety injection device thereof

Abstract

The utility model relates to an injection auxiliary device and a safety injection device thereof, which are characterized in that the injection auxiliary device consisting of an outer sleeve and a push rod stabilizer is arranged aiming at a special slender disposable syringe and combined with an existing needle head protection device, so that effective connection and use of the slender disposable syringe and the needle head protection device are realized; the production cost is saved; and the push rod stabilizer can protect the slender push rod, so that the medicine pushing process of the push rod is more stable.

Description

Technical Field

[0001] This utility model relates to an injection auxiliary device used in a safe injection device, which is intended to be compatible with special thin and long disposable syringes, and belongs to the field of medical injection devices. Background Technology

[0002] The applicant has previously applied for and published Chinese Patent Publication No. CN217245956U, a syringe protection device for easy installation of syringes; Chinese Patent Publication No. CN214911888U, a syringe needle protection device and its safety syringe; Chinese Patent Publication No. CN214181356U, a safety buckle and its syringe needle protection device; and Chinese Patent Publication No. CN213609016U, a syringe needle protection device. The related safety syringe products, after injection, use the relative movement of the inner and outer cylinders to shield the syringe needle, thereby preventing punctures and accidental injury.

[0003] However, including the aforementioned patents, most commercially available safety syringe / needle protection devices are designed for standard disposable syringes or prefilled syringes (PFS), and the diameter and length of the compatible syringes are specifically defined. However, in the biopharmaceutical field, some pharmaceutical products, due to special reasons such as high viscosity, while still requiring injection, necessitate the use of special disposable syringes, particularly long and thin syringes, such as... Figure 1 As shown.

[0004] For example Figure 1 The slender disposable syringe shown also requires needle shielding after use. However, developing a separate mold to fit and install such syringes, in conjunction with existing safety syringe / needle protection devices, would undoubtedly increase costs.

[0005] In particular, the drugs in long and thin syringes are generally more viscous, requiring greater force to be applied during injection. At this time, the long and thin plunger is prone to bending and deformation, resulting in uneven drug delivery or even failure.

[0006] In response to the above situation, it is necessary to design an injection assistance device specifically for slender disposable syringes. This device would allow the slender disposable syringe to be properly installed into the existing needle protection device. This would not only assist in pushing the medication and prevent the plunger from bending or deforming, but also rely on the reliable structure of the existing needle protection device to automatically cover the needle after injection, thereby improving safety. Utility Model Content

[0007] The purpose of this utility model is to provide an injection assistance device and a safe injection device. In response to the safety requirements of using slender disposable syringes, it combines existing needle protection devices for effective connection and installation, so as to not only assist in pushing the medicine, but also automatically cover the needle after injection.

[0008] To achieve the above-mentioned utility model objectives, the first aspect of this utility model provides an injection auxiliary device, including an outer sleeve and a push rod stabilizer;

[0009] The outer sleeve has a tube open at both ends, and the inside of the tube is a tube cavity.

[0010] The top of the tube extends outward to both sides to form outer tube wings;

[0011] The top of the tube is equipped with a protective sleeve mounting base;

[0012] The upper outer side of the outer sleeve is provided with a limiting block. Two limiting blocks are a pair and are set opposite each other, thus forming a limiting groove in the middle; the top of the limiting groove is open.

[0013] Two pairs of limiting blocks are provided on the upper outer side of the tube, thus forming two limiting grooves;

[0014] The push rod stabilizer has a push head at the top and a mounting buckle at the bottom of the push head;

[0015] The lower part of the pusher is equipped with an excitation sleeve;

[0016] The two sides of the pusher extend downward to form a stabilizing bar, which is inserted into the limiting groove;

[0017] The stabilizer bar matches the limiting groove to form a sliding guide.

[0018] As a further improvement of this utility model, the bottom of the tube cavity is tapered inward, with a bottom surface and a through hole formed in the middle.

[0019] Furthermore, it is equipped with a pen cap, which has a pen cap tube, inside which is a pen cap cavity;

[0020] The pen cap is detachably connected to the bottom of the outer sleeve.

[0021] Furthermore, the top of the pen cap extends outward to form a limiting platform, the diameter of which is larger than the through hole.

[0022] The top of the limiting platform extends outward, forming several limiting claws;

[0023] The limiting claw matches the through hole, and the limiting claw is detachably snapped into the through hole.

[0024] As a further improvement of this utility model, a number of protective cover fixing claws are provided around the protective cover mounting base.

[0025] As a further improvement of this utility model, a reinforcing rib is provided between the outer wing and the upper wall of the tube.

[0026] As a further improvement of this utility model, the cross-section of the limiting block is "L" shaped;

[0027] Two limiting grooves are symmetrically arranged on both sides of the upper outer side of the tube.

[0028] Furthermore, a limiting spring is provided at the top of the limiting groove, and the limiting spring has an inwardly positioned limiting protrusion;

[0029] The stabilizer bar has several positioning grooves, which are arc-shaped and match the limiting protrusions of the limiting spring.

[0030] Furthermore, a limiting spring is provided at the top of the limiting groove;

[0031] The bottom of the stabilizer bar is equipped with a limiting plate, which matches the limiting spring.

[0032] A second aspect of this utility model provides a safe injection device, including a slender disposable syringe, a needle protection device, and an injection auxiliary device as described above;

[0033] A slim, disposable syringe, comprising a syringe barrel, plunger, piston, needle hub, needle, and cap;

[0034] The needle protection device includes a protective outer sheath, a protective inner sheath, and a protective spring;

[0035] The syringe barrel of the slender disposable syringe is connected to the inner protective sleeve of the needle protection device, the top of the plunger is connected to the top of the plunger stabilizer, and the outer protective sleeve is installed inside the barrel of the outer sleeve. The protective cap is connected to the pen cap.

[0036] When using the safety injection device of this utility model, first remove the pen cap; at the same time as removing the pen cap, remove the protective cap as well, thereby exposing the needle.

[0037] With the pen cap removed, hold the outer tube of the safety injection device, pointing the needle towards the injection site. Apply force to insert the needle, then press your thumb against the pusher head at the top of the pusher stabilizer, while hooking two other fingers around the outer tube wing. Apply force with your hand, causing your thumb to drive the pusher head. At this time, the stabilizing rods on both sides of the pusher stabilizer slide within the limiting groove, providing auxiliary support for the movement of the pusher stabilizer. The pusher head drives the pusher rod, which in turn causes the piston to move inside the injection tube, injecting the medication from the needle connected to the bottom of the injection tube.

[0038] When the piston moves to the bottom of the syringe barrel, the drug is completely ejected from the syringe barrel. At this time, the pusher head of the push rod stabilizer also approaches the top of the protective inner sleeve. In particular, the trigger sleeve at the bottom of the pusher head contacts the unlocking ramp of the protective inner sleeve, which drives the unlocking ramp to push the outer buckle outward, causing the outer buckle to disengage from the inner buckle. At this time, the injection is completed, but the fingers still apply force to press the various parts together.

[0039] Remove the needle of the safety injection device of this utility model from the injection site, and then place the entire safety injection device on a safe table. When the finger is removed, the components are no longer restrained by the finger, and the protective spring releases its elasticity, causing the inner protective sleeve to pop out relative to the outer protective sleeve and the outer sleeve tube. The inner protective sleeve drives the flange, which in turn drives the injection tube. The injection tube drives the piston, push rod, needle seat, and needle to move together relative to the outer sleeve tube, thereby gradually moving the needle past the bottom surface of the outer sleeve tube and retracting it into the tube cavity, thus achieving the function of shielding the needle.

[0040] This invention relates to an injection auxiliary device and its safety injection device. Targeting special slender disposable syringes, it combines existing needle protection devices with an injection auxiliary device consisting of an outer sleeve and a plunger stabilizer. This achieves effective connection and use of the slender disposable syringe and the needle protection device, saving production costs. Furthermore, the plunger stabilizer can protect the slender plunger, making the drug delivery process more stable. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of a slender disposable syringe;

[0042] Figure 2 This is a schematic diagram of the overall structure of the safety injection device of this utility model before use;

[0043] Figure 3 Exploded views of the components of the safety injection device of this utility model;

[0044] Figure 4 This is a schematic diagram of the overall structure of the needle protection device;

[0045] Figure 5 This is a schematic diagram of the internal structure of the needle protection device;

[0046] Figure 6 This is a schematic diagram of the overall structure of a long, thin disposable syringe after it has been installed inside a needle protection device.

[0047] Figure 7 for Figure 6 A partial sectional view;

[0048] Figure 8 This is a schematic diagram of the overall structure of the outer sleeve of this utility model;

[0049] Figure 9 This is a schematic diagram of the internal structure of the outer sleeve of this utility model;

[0050] Figure 10 A schematic diagram showing the installation of the protective jacket of the needle protection device inside the jacket sleeve;

[0051] Figure 11 This is a schematic diagram of the overall structure of the push rod stabilizer of this utility model;

[0052] Figure 12 This is a schematic diagram of the internal structure of the push rod stabilizer of this utility model;

[0053] Figure 13 This is a schematic diagram of the combined structure of the outer sleeve and the push rod stabilizer.

[0054] Figure 14 for Figure 13 A magnified view of a portion of the image;

[0055] Figure 15 This is a schematic diagram of the overall structure of the pen cap of this utility model;

[0056] Figure 16 This is a schematic diagram of the internal structure of the pen cap of this utility model;

[0057] Figure 17 This is a schematic diagram of the internal structure when a pen cap is combined with the protective cap of a slim disposable syringe and installed on the outer sleeve;

[0058] Figure 18 This is a schematic diagram of the overall structure of the safety injection device of this utility model before use;

[0059] Figure 19 for Figure 18 Internal structure diagram under the condition;

[0060] Figure 20 This is a schematic diagram of the overall structure of the safety injection device of this utility model when the pen cap is removed and the device is waiting to be injected.

[0061] Figure 21 for Figure 20 Internal structure diagram under the condition;

[0062] Figure 22 A schematic diagram of the internal structure of the assembly of a removed pen cap and a protective cap for a long, thin disposable syringe;

[0063] Figure 23 This is a schematic diagram of the overall structure of the safety injection device of this utility model during the injection process;

[0064] Figure 24 for Figure 23Internal structure diagram under the condition;

[0065] Figure 25 for Figure 24 Enlarged schematic diagram of a part

[0066] Figure 26 This is a schematic diagram of the overall structure of the safety injection device of this utility model, showing the needle protection device in the activation preparation state after injection is completed.

[0067] Figure 27 for Figure 26 Internal structure diagram under the condition;

[0068] Figure 28 for Figure 26 Schematic diagram of the activation preparation state of the needle protection device in the specified state;

[0069] Figure 29 This is a schematic diagram of the overall structure of the safety injection device of this utility model under needle protection conditions;

[0070] Figure 30 for Figure 29 A schematic diagram of the internal structure under the specified conditions. Detailed Implementation

[0071] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0072] like Figure 1 As shown, this is a slender disposable syringe. Its overall structure is basically the same as a conventional disposable syringe or PFS (Pre-Flush Filter), including a syringe barrel 11, plunger 12, piston 13, needle hub 14, needle 15, soft protective cap 16, and hard protective cap 17. However, the syringe barrel 11 is more slender. To accommodate existing needle protection devices, reinforcing ribs are added to the outside of the syringe barrel 11's drug cartridge, thus increasing the overall outer diameter. Generally, only one protective cap is needed on the outside of the needle 15, but for PFS products, in order to… To prevent leaks during transport, a soft cap 16 with good elasticity is first placed outside the needle 15 to achieve a seal. To facilitate the removal of the soft cap 16, a hard cap 17 is then placed outside the soft cap 16. The soft cap 16 is embedded in the hard cap 17, which provides external support for the soft cap 16. This prevents the soft cap 16 from falling off the needle hub 14 / needle 15 due to vibration during storage and transportation, and also prevents possible bumps and knocks during storage and transportation that could cause the soft cap 16 to be deformed under pressure, affecting the needle 15.

[0073] The injection auxiliary device of this utility model mainly includes an outer sleeve 3, a push rod stabilizer 4, and a pen cap 5. Together with the needle protection device 2 and a slender disposable syringe, it forms the safe injection device of this utility model. Its overall structure is as follows: Figure 2 As shown, the specific components are as follows: Figure 3 As shown.

[0074] Needle protection device 2, such as Figure 4 , Figure 5 As shown, or referring to the safety buckle and syringe needle protection device of Chinese Patent Publication No. CN214181356U, or the syringe needle protection device of Chinese Patent Publication No. CN213609016U, it consists of a protective outer sleeve 21, a protective inner sleeve 22, and a protective spring 23; the protective outer sleeve 21 is provided with a protective outer sleeve 211, and the upper part is provided with protective outer sleeve wings 212 extending outward to both sides; the protective inner sleeve 22 is installed inside the protective outer sleeve 21, and is provided with a protective inner sleeve 221, which can slide axially relative to the protective outer sleeve 211; the upper part of the protective inner sleeve 22 is provided with a mounting seat 222, and the mounting seat 222 is provided with several mounting claws 223 around its perimeter; A protective spring 23 is provided between the upper part of the outer protective sleeve 21 and the upper part of the inner protective sleeve 22. In order to keep the protective spring 23 in a compressed and energy-storing state, the upper parts of the outer protective sleeve 21 and the inner protective sleeve 22 are connected by a buckle. That is, the upper part of the outer protective sleeve 21 is provided with an inner buckle 215, and the upper part of the inner protective sleeve 22 is provided with an outer buckle 225. In particular, the upper part of the outer buckle 225 is provided with an unlocking slope 226. By squeezing the unlocking slope 226, the outer buckle 225 can be pushed outward, causing the outer buckle 225 to deform outward, and then the outer buckle 225 separates from the inner buckle 215. Then the outer protective sleeve 21 and the inner protective sleeve 22 separate, the protective spring 23 is released, and the inner protective sleeve 22 bounces up relative to the outer protective sleeve 21.

[0075] like Figure 6 , Figure 7 As shown, a slender disposable syringe is installed inside the needle protection device 2 and fixed to the protective inner sleeve 22 of the needle protection device 2. Specifically, the flange 112 at the top of the syringe barrel 11 is inserted into the mounting seat 222 on the upper part of the protective inner sleeve 22 and is limited by the mounting claw 223, so that the syringe barrel 11 is fixed inside the protective inner sleeve 22 and the syringe barrel 11 can move axially with the protective inner sleeve 22; the reinforcing ribs of the syringe barrel 11 are basically against the inner wall of the protective inner sleeve 22 to stabilize the radial position of the syringe barrel 11; and the lower part of the syringe barrel 11 extends out of the needle protection device 2.

[0076] The outer sleeve 3 of the injection auxiliary device of this utility model, such as Figure 8 , Figure 9As shown, its primary function is to extend the protective sleeve 21 of the needle protection device 2; the sleeve tube 3 has a tube 31 with openings at both ends, and the inside of the tube 31 is a tube cavity 32. The size of the tube cavity 32 matches the outer diameter of the protective sleeve tube 211 of the protective sleeve 21; the bottom of the tube cavity 32 tapers inward and has a bottom surface 321, with a through hole 322 in the middle; the top of the tube 31 extends outward to both sides to form outer tube wings 33, which are used to place fingers, increasing the ease of operation and stability of the injection process; because the outer tube wings 33 are thin, to further increase reliability, reinforcing ribs 34 are provided between the outer tube wings 33 and the upper wall of the tube 31; the top of the tube 31 has a protective sleeve mounting seat 35, and several protective sleeve fixing claws 36 are provided around the protective sleeve mounting seat 35, such as Figure 10 As shown, the size of the protective jacket mounting base 35 matches the size of the protective jacket wing 212 of the protective jacket 21. After the protective jacket wing 212 is inserted into the protective jacket mounting base 35, the protective jacket fixing claw 36 locks the protective jacket wing 212, thereby reliably fixing the protective jacket 21 inside the jacket tube 3. The appropriate jacket tube 3 can move with the protective jacket 21. In particular, the length of the protective jacket 21 has been extended to match the length of the injection tube 11.

[0077] The upper outer side of the outer sleeve 3's tube 31 is also provided with a limiting block 37. The cross-section of the limiting block 37 is preferably "L" shaped. Two limiting blocks 37 are arranged in a pair, facing each other, thereby forming a limiting groove 38 in the middle. Preferably, two pairs of limiting blocks 37 are provided on the upper outer side of the tube 31, thereby forming two limiting grooves 38. The two limiting grooves 38 are preferably symmetrically arranged on both sides of the upper outer side of the tube 31. The top of the limiting groove 38 is through, and preferably, a limiting spring 39 is also provided, which has an inwardly extending limiting protrusion.

[0078] The push rod stabilizer 4 of the injection auxiliary device of this utility model, such as Figure 11 , Figure 12As shown, the top is provided with a push head 41, which is convenient for placing a finger and provides a plane for applying the pushing force during injection; the bottom of the push head 41 is provided with a mounting buckle 42, and the mounting buckle 42 has a mounting cavity 43 for connecting with the top connector 122 of the push rod 12; the lower part of the push head 41 is provided with an excitation sleeve 44, which matches the unlocking slope 226 of the protective inner sleeve 22; the two sides of the push head 41 extend downward to form a stabilizing rod 45, which can be inserted into the limiting groove 38 and slide axially within the limiting groove 38; The stabilizer bar 45 has several positioning grooves 46, which are arc-shaped and match the limiting protrusions of the limiting spring 39, facilitating the entry and exit of the limiting protrusions from the positioning grooves 46. Furthermore, the bottom of the stabilizer bar 45 has a limiting piece 47, which matches the limiting spring 39. When the stabilizer bar 45 is inserted into the limiting groove 38, the limiting piece 47 passes over the limiting spring 39, thus preventing the stabilizer bar 45 from being pulled out of the limiting groove 38. Figure 13 , Figure 14 As shown, the push rod stabilizer 4 is assembled with the outer sleeve 3 via the stabilizer rod 45. Under the guidance of the stabilizer rod 45 and the limiting groove 38, the push rod stabilizer 4 can move axially relative to the outer sleeve 3. During the axial movement, the limiting protrusion continuously enters different positioning grooves 46, thereby providing segmented feedback to the operator during the pushing process.

[0079] The pen cap 5 of the injection auxiliary device of this utility model, such as Figure 15 , Figure 16 As shown, a pen cap holder 51 is provided, which contains a pen cap cavity 52 for accommodating a hard protective cap 17. Several fixing springs 53 are provided inwardly on the wall surface of the pen cap holder 51 to match the removal protrusion 171 on the hard protective cap 17, thereby fixing the hard protective cap 17 within the pen cap cavity 52. ​​Furthermore, the top of the pen cap holder 51 extends outward to form a limiting platform 54, the diameter of which is larger than the through hole 322, thereby preventing the pen cap holder 51 from extending into the tube cavity 32. Even further, the top of the limiting platform 54 extends outward to form several limiting claws 55, which can engage with the through hole 322. Figure 17 As shown, when in use, the pen cap 5 is fastened to the hard protective cap 17, and the limiting claw 55 is engaged in the through hole 322. When the pen cap 5 is removed, the hard protective cap 17 and the soft protective cap 16 can be removed together. The soft protective cap 16 leaves the needle seat 14, exposing the needle tip 15. When the pen cap 5 is removed, the limiting claw 55 passes through the through hole 322, making it impossible for the pen cap 5 to be easily inserted back into the bottom of the outer sleeve 3, thereby preventing tampering and avoiding drug abuse caused by the destruction of the sterile environment due to the removal of the soft protective cap 16. Figure 17 As shown, the hard cap 17 and the soft cap 16 are connected by a limiting block 166 and a limiting groove 176 at the top of both.

[0080] This invention relates to an injection auxiliary device that assembles a slender disposable syringe with a needle protection device 2. The syringe barrel 11 of the slender disposable syringe is connected to the protective inner sleeve 22 of the needle protection device 2. The top of the push rod 12 is connected to the top of the push rod stabilizer 4. The protective outer sleeve 21 is installed inside the barrel 31 of the outer sleeve 3. The needle 15, along with the soft protective cap 16 and the hard protective cap 17, passes through the through hole 322 at the bottom of the outer sleeve 3 and is inserted into the pen cap 5. The pen cap 5 is secured to the bottom of the outer sleeve 3 by a limiting claw 55, thus forming a well-sealed safety injection device of this invention. The assembled state and the state before use are as follows: Figure 18 , Figure 19 As shown. Figure 19 The diagram further illustrates the connection between the top connector 122 of the push rod 12 and the mounting buckle 42 and mounting cavity 43 on the top of the push rod stabilizer 4.

[0081] When using the safety injection device of this utility model, first remove the pen cap 5, as follows: Figure 20 , Figure 21 As shown; when the pen cap 5 is removed, the soft protective cap 16 and the hard protective cap 17 are also removed together, as shown. Figure 22 As shown, this allows the needle tip 15 to be exposed.

[0082] After removing the pen cap 5, hold the outer tube 31 of the outer sleeve 3 with the needle 15 facing the injection site. Apply force to insert the needle 15. Then, press the thumb against the push head 41 at the top of the push rod stabilizer 4, while hooking two other fingers onto the outer sleeve 33 of the outer sleeve 3. Apply force with your hand so that your thumb drives the push head 41 to move. Figure 23 , Figure 24 , Figure 25 As shown, at this time, the stabilizing rods 45 on both sides of the push rod stabilizer 4 slide in the limiting groove 38, providing auxiliary support for the movement of the push rod stabilizer 4. During the process, the stabilizing rods 45 slide relative to the limiting springs 39, so that the several positioning grooves 46 arranged sequentially on the stabilizing rods 45 continuously contact and separate from the limiting protrusions of the limiting springs 39, thereby providing segmented feedback to the operator during the drug injection process, ensuring that the operator can better control the thumb pushing force and ensure that the drug is injected within the specified time. The push head 41 drives the push rod 12 to move, which in turn causes the piston 13 to move in the injection tube 11, injecting the drug 10 in the injection tube 11 from the needle 15 connected to the bottom of the injection tube 11.

[0083] When the piston 13 moves to the bottom of the injection tube 11, the drug 10 is completely pushed out of the injection tube 11, minimizing residual dosage and maximizing the use of the drug 10. At the same time, the push head 41 of the push rod stabilizer 4 approaches the top of the protective inner sleeve 22, especially the trigger sleeve 44 at the bottom of the push head 41 contacts the unlocking ramp 226 of the protective inner sleeve 22, pushing the unlocking ramp 226 outward to drive the outer latch 225, causing the outer latch 225 to disengage from the inner latch 215. Figure 26 , Figure 27 , Figure 28 As shown; at this point, the injection is complete, but the fingers are still applying force to press the various parts together.

[0084] The needle 15 of the safety injection device of this utility model is pulled out from the injection site. Then, the entire safety injection device is placed on a safe table. When the finger is removed, the components lack the restraining force of the finger, and the protective spring 23 releases its elastic force, causing the inner protective sleeve 22 to pop out relative to the outer protective sleeve 21 and the outer sleeve 3. The inner protective sleeve 22 drives the flange 112, which in turn drives the injection tube 11. The injection tube 11 drives the piston 13, push rod 12, needle seat 14, and needle 15 to move relative to the outer sleeve 3, thereby gradually moving the needle 15 past the bottom surface 321 of the outer sleeve 3 and retracting it into the tube cavity 32, achieving the function of shielding the needle 15. During this process, the push rod 12 drives the push rod stabilizer 4 to move, causing the push rod stabilizer 4 to also rise. Figure 29 , Figure 30 As shown.

[0085] Combination Figure 28 The entire protective release process is as follows:

[0086] ① The trigger sleeve 44 moves downward;

[0087] ② The trigger sleeve 44 presses the unlocking ramp 226, pushing the unlocking ramp 226 outward;

[0088] ③ The unlocking ramp 226 drives the outer buckle 225 to move outward, causing the outer buckle 225 to disengage from the inner buckle 215;

[0089] ④ After the finger is removed, the protective spring 23 is released, pushing the protective inner sleeve 22 to move;

[0090] ⑤ The top of the inner sleeve 22 pushes the flange 112 to move;

[0091] ⑥ The flange 112 drives the injection tube 11, which in turn drives the components connected to the injection tube 11 to move together.

[0092] The preferred embodiments of this utility model have been described in detail above, but this utility model is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this utility model, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. Injection aid, characterized in that The outer sleeve is provided with a barrel with two open ends, the inside of the barrel is a barrel cavity, The top of the barrel extends to both sides to form an outer barrel wing. The top of the barrel is provided with a protective outer sleeve mounting seat. The outer side of the upper part of the barrel is provided with two pairs of limiting blocks, thereby forming two limiting grooves. The top of the limiting groove is through. The top of the barrel is provided with a push head, and the bottom of the push head is provided with a mounting buckle. The bottom of the push head is provided with an excitation sleeve. The two sides of the push head extend downward to form a stabilizing rod, which is inserted into the limiting groove. The stabilizing rod and the limiting groove are matched to form a sliding guide. The bottom of the barrel cavity is inwardly retracted and provided with a bottom surface, forming a via hole in the middle.

2. The injection aid of claim 1, wherein A pen cap is provided, and the pen cap is provided with a pen cap barrel, which is a pen cap cavity.

3. The injection aid of claim 2, wherein The pen cap is detachably connected to the bottom of the outer sleeve. The top of the pen cap barrel extends outward to form a limiting table, and the diameter of the limiting table is greater than that of the via hole.

4. The injection aid of claim 3, wherein The top of the limiting table extends outward to form a plurality of limiting spring claws. The limiting spring claws are matched with the via hole, and the limiting spring claws are detachably buckled into the via hole. A plurality of protective sleeve fixing claws are arranged around the protective outer sleeve mounting seat.

5. The injection aid of claim 1, wherein, A reinforcing rib is arranged between the outer barrel wing and the upper wall of the barrel.

6. The injection aid of claim 1, wherein, The cross section of the limiting block is "L" shaped.

7. The injection aid of claim 1, wherein, The two limiting grooves are symmetrically arranged on both sides of the upper outer side of the barrel. The top of the limiting groove is provided with a limiting spring piece having a limiting protrusion arranged inwardly.

8. The injection aid of claim 1 or 7, wherein A plurality of positioning grooves are arranged on the stabilizing rod, and the positioning grooves are arc-shaped grooves matched with the limiting protrusions of the limiting spring pieces. The top of the limiting groove is provided with a limiting spring piece.

9. The injection aid of claim 1 or 7, wherein, The bottom of the stabilizing rod is provided with a limiting piece matched with the limiting spring piece. The elongated disposable syringe, the needle protection device, and the injection aid device as claimed in any one of claims 1-9; 10. A safety injection device characterized by, The elongated disposable syringe, the needle protection device, and the injection aid device as claimed in any one of claims 1-9; The elongated disposable syringe, the needle protection device, and the injection aid device as claimed in any one of claims 1-9; The injection barrel of the elongated disposable syringe and the protective inner sleeve of the needle protection device are connected together, the top of the push rod and the top of the push rod stabilizer are connected together, and the protective outer sleeve is mounted in the barrel of the outer sleeve. ​

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