A small-dose needle-free injector

Abstract

This utility model relates to the field of medical device technology, and discloses a small-dose needle-free injector, comprising: a gun body having an activation chamber and a control valve; an adjusting rod device disposed at one end of the activation chamber; a ejector pin disposed within the activation chamber, the ejector pin including a striking head and a striking pin, the striking head being disposed at the end of the striking pin near the adjusting rod device, the end face of the striking head, the inner wall of the activation chamber, and the surface of the adjusting rod device forming a pushing chamber, the pushing chamber communicating with the control valve, and a guide portion provided along the outer periphery of the striking head; a front cover disposed at the other end of the activation chamber, the front cover having a striking pin through hole, the striking pin passing through the striking pin through hole and extending outward, a guide groove being provided along the outer periphery of the striking pin through hole, the guide portion being able to extend into the guide groove, and an elastic element being provided between the bottom of the guide groove and the striking pin head. This utility model provides stable striking pin movement during injection and high precision for small-dose injection.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a small-dose needle-free injector. Background Technology

[0002] A needle-free injector is a syringe that does not require the use of a needle. It typically uses high pressure to spray the injection solution into human tissue to deliver drugs, making it a safer, more hygienic, and more comfortable injection method.

[0003] Needle-free injectors are frequently used in aesthetic and medical procedures. Some treatments require small doses per injection, but existing needle-free injectors suffer from excessive and unstable needle movement during injection, making it difficult to control the injection rate and increasing the risk of over-injection. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides a small-dose needle-free injector with stable needle movement during the injection process and high precision for small-dose injection.

[0005] To address the aforementioned problems, this invention proposes a small-dose needle-free injector, comprising:

[0006] The gun body has an firing chamber and a control valve;

[0007] An adjusting rod device is provided at one end of the excitation chamber;

[0008] A push pin is disposed in the excitation chamber. The push pin includes a striking head and a striking pin. The striking head is disposed at one end of the striking pin near the adjusting rod device. The end face of the striking head, the inner wall of the excitation chamber, and the surface of the adjusting rod device form a pushing chamber. The pushing chamber is connected to a control valve. The striking head is provided with a guide portion along the outer periphery of the striking pin.

[0009] A front cover is located at the other end of the excitation chamber. The front cover has a firing pin through hole, through which the firing pin passes and extends outward. A guide groove is provided along the outer periphery of the firing pin through hole, and the guide part can extend into the guide groove. An elastic element is provided between the bottom of the guide groove and the firing pin head.

[0010] As an improvement to the above technical solution, a guide sleeve is provided on the side of the firing pin head facing the firing pin, and the guide part is provided on the guide sleeve;

[0011] The guide sleeve has a travel cavity on the side near the firing pin head. The firing pin extends through the travel cavity toward the front cover and can slide along the travel cavity.

[0012] As an improvement to the above technical solution, a first sealing ring is provided at one end of the firing pin near the firing pin head, and the first sealing ring abuts against the inner wall of the stroke cavity;

[0013] The inner wall of the firing pin through hole is provided with a second sealing ring, which abuts against the firing pin.

[0014] As an improvement to the above technical solution, the inner wall of the guide portion, the outer wall of the firing pin, and the extension of the firing pin through hole form a guide cavity.

[0015] The guide portion is provided with a first air guide hole, which communicates with the guide cavity;

[0016] The firing pin has an air passage at one end near the firing pin head, and a second air guide hole for connecting the air passage and the stroke chamber.

[0017] As an improvement to the above technical solution, the elastic element is a compression spring, which is sleeved on the guide portion;

[0018] One end of the compression spring is abutted or fixedly connected to the striker head, and the other end is abutted or fixedly connected to the bottom of the guide groove.

[0019] As an improvement to the above technical solution, a first buffer pad is provided at the bottom of the guide groove;

[0020] The adjusting rod device has a second buffer pad at one end near the ejector pin.

[0021] As an improvement to the above technical solution, the adjusting rod device includes an adjusting rod and a limiting part;

[0022] The adjusting rod has an adjusting thread at the end away from the ejector pin, and the excitation chamber has an adjusting through hole at the end near the adjusting rod. The adjusting thread extends outward through the adjusting through hole and is threadedly connected to the adjusting through hole. The adjusting thread is provided with a turning part at the end of the adjusting thread outside the excitation chamber, and the adjusting rod has a limiting part at the end near the ejector pin.

[0023] As an improvement to the above technical solution, the excitation chamber is provided with a sealing groove, the adjustment through hole is provided at the bottom of the sealing groove, and a third sealing ring is provided along the inner wall of the sealing groove, the third sealing ring abutting against the adjustment rod.

[0024] As an improvement to the above technical solution, the side wall of the firing pin head is provided with a fourth sealing ring, which abuts against the inner wall of the excitation chamber.

[0025] The following are the beneficial effects of implementing this utility model:

[0026] This invention relates to a needle-free injector, wherein the ejector pin includes an impact head and an impact pin. The impact head has a guide portion along the outer periphery of the impact pin. The firing chamber has a front cover at the end near the impact pin, and the front cover has an impact pin through hole. A guide groove is provided along the outer periphery of the impact pin through hole, and the guide portion can extend into the guide groove. First, the cooperation between the guide portion and the guide groove provides precise guidance for axial movement, preventing the ejector pin from deflecting or rotating under the push of high-pressure gas, ensuring that the impact pin advances in a straight line. Furthermore, the precise linear movement ensures that the liquid is sprayed at a constant speed and direction, avoiding dose dispersion or inconsistent penetration depth caused by oscillation. This makes this invention suitable for small-dose needle-free injectors, providing stable and highly accurate small-dose injections. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of a needle-free injector according to an embodiment of the present invention;

[0028] Figure 2 yes Figure 1 Enlarged view of point A in the image;

[0029] Figure 3 This is a cross-sectional view of a ejector pin according to an embodiment of the present invention;

[0030] Figure 4 This is a cross-sectional view of the front cover according to an embodiment of the present invention;

[0031] Figure 5 This is a cross-sectional view of an embodiment of the adjusting rod device of this utility model. Detailed Implementation

[0032] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be described in further detail below with reference to the accompanying drawings.

[0033] See Figures 1 to 5 As shown, this embodiment of the present invention provides a small-dose needle-free injector, comprising:

[0034] Gun body 1, which has an firing chamber 11 and a control valve 12;

[0035] An adjusting rod device 2 is located at one end of the excitation chamber 11;

[0036] This embodiment of the invention improves the structure of the ejector pin and the front cover to reduce the amount of oscillation of the ejector pin during the excitation process.

[0037] Specifically, the ejector pin 3 is disposed in the excitation chamber 11. The ejector pin 3 includes an impact head 31 and an impact pin 32. The impact head 31 is disposed at one end of the impact pin 32 near the adjusting rod device 2. The end face of the impact head 31, the inner wall of the excitation chamber 11, and the surface of the adjusting rod device 2 form a pushing chamber 13. The pushing chamber 13 is connected to the control valve 12. The impact head 31 is provided with a guide portion 34 along the outer periphery of the impact pin.

[0038] A front cover 4 is located at the other end of the excitation chamber 11. The front cover 4 has a firing pin through hole 41. The firing pin 32 passes through the firing pin through hole 41 and extends outward. A guide groove 42 is provided along the outer periphery of the firing pin through hole 41. The guide part 34 can extend into the guide groove 42. An elastic element 43 is provided between the bottom of the guide groove 42 and the firing pin head 32.

[0039] Working principle of this utility model embodiment:

[0040] When the control valve 12 connects the high-pressure gas source to the push chamber, the high-pressure gas pushes the striker head 31, causing the striker 32 to slide towards the front cover 4. At this time, the guide portion 34 on the outer periphery of the striker 32 slides along the guide groove 42, and the elastic element 43 between the bottom of the guide groove 42 and the striker head 31 is compressed.

[0041] First, the cooperation between the guide portion 34 and the guide groove 42 provides precise guidance for axial movement, preventing the ejector pin 3 from deflecting or rotating under the pressure of high-pressure gas, and ensuring that the ejector pin 32 advances in a straight line. Furthermore, the precise linear movement ensures that the liquid is sprayed at a constant speed and direction, avoiding dose dispersion or inconsistent penetration depth caused by oscillation. This makes this invention suitable for small-dose needle-free injectors, providing stable and highly accurate small-dose injections.

[0042] In some embodiments, the firing pin head 31 is provided with a guide sleeve 33 on the side facing the firing pin 32, and the guide portion 34 is provided on the guide sleeve 33;

[0043] The guide sleeve 33 has a travel cavity 36 on the side near the striker head 31. The striker 32 extends through the travel cavity 36 toward the front cover 4 and can slide along the travel cavity 36.

[0044] In the specific implementation process, the firing pin head 31, guide sleeve 33, and firing pin 32 are separate structures. A stroke cavity 36 is carved into the guide sleeve 33, through which the firing pin 32 extends towards the front cover 4. The firing pin head 32 is fixedly connected to the guide sleeve 33, enclosing the stroke cavity 36. First, the aforementioned separate structure provides sliding space for the firing pin 32, achieving dynamic alignment and reducing swaying and vibration. Second, it isolates high-pressure gas, ensuring axial transmission of thrust and preventing lateral forces on the firing pin 32. Finally, the inner wall of the stroke cavity 36 provides auxiliary guidance for the firing pin 32, significantly enhancing the linearity of its movement and further reducing swaying.

[0045] Preferably, the firing pin 32 is provided with a first sealing ring 35 at one end near the firing pin head 31, and the first sealing ring 35 abuts against the inner wall of the stroke cavity 36;

[0046] The inner wall of the firing pin through hole 41 is provided with a second sealing ring 44, which abuts against the firing pin 32.

[0047] The first sealing ring 35 and the second sealing ring 44, by providing elastic radial support and dual-point constraint, not only achieve the sealing function but also play a role in auxiliary guidance and sway reduction. This enhances the linearity and stability of the impact pin 32's movement, ultimately improving the accuracy and reliability of small-dose needle-free injection.

[0048] Preferably, the inner wall of the guide portion 34, the outer wall of the firing pin, and the extension of the firing pin through hole form a guide cavity.

[0049] The guide portion 34 is provided with a first air guide hole 341, and the first air guide hole 341 is in communication with the guide cavity;

[0050] The striking pin 32 is provided with an air passage 321 at one end near the striking pin head, and a second air guide hole 322 for connecting the air passage 321 and the stroke cavity.

[0051] It should be noted that there is a predetermined distance between the firing pin 32 and the guide sleeve 33. That is, the guide cavity, the stroke cavity 36, the first air guide hole 341 and the second guide hole 322 are interconnected.

[0052] The first vent 341 and the second vent 322 together ensure that the pressure in the guide cavity and the stroke cavity 36 remains balanced during the movement of the striking needle 32. This pressure balance ensures minimal resistance during the movement of the striking needle 32, resulting in stable and predictable speed and improved repeatability and consistency of injection. The smooth movement of the striking needle 32 reduces wobbling, ensuring consistent force and angle of impact with the ampoule each time, thereby guaranteeing the accuracy and directionality of the drug injection dosage.

[0053] In some embodiments, the elastic element 43 is a compression spring, which is sleeved on the guide portion 34;

[0054] One end of the compression spring 43 is abutted or fixedly connected to the striker head 31, and the other end is abutted or fixedly connected to the bottom of the guide groove 42.

[0055] Preferably, a first buffer pad 45 is provided at the bottom of the guide groove 42; a second buffer pad 23 is provided at the end of the adjusting rod device 2 near the ejector pin 3. The first buffer pad 45 and the second buffer pad 23 can buffer the impact generated when the ejector pin 3 moves, effectively improving the mechanical life.

[0056] In some embodiments, the adjusting rod device 2 includes an adjusting rod 21 and a limiting part 22;

[0057] The adjusting rod 21 has an adjusting threaded portion 24 at the end away from the ejector pin 3. The excitation chamber 11 has an adjusting through hole at the end near the adjusting rod 24. The adjusting threaded portion 24 extends outward through the adjusting through hole and is threadedly connected to the adjusting through hole. The adjusting threaded portion 24 has a turning portion 25 at the end of the adjusting threaded portion 24 located outside the excitation chamber 11. The adjusting rod 21 has a limiting portion 22 at the end near the ejector pin 3.

[0058] It should be noted that when it is necessary to fine-tune the injection dosage of the needleless injector, the length of the adjusting rod 21 extending into the excitation chamber can be changed by turning the turning part 25.

[0059] Preferably, the excitation chamber 11 is provided with a sealing groove 14, the adjustment through hole is provided at the bottom of the sealing groove 14, and a third sealing ring 15 is provided along the inner wall of the sealing groove 14, the third sealing ring 15 abutting against the adjustment rod 21.

[0060] In some embodiments, the sidewall of the firing pin head 31 is provided with a fourth sealing ring 311, which abuts against the inner wall of the excitation chamber 11.

[0061] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications are also considered to be within the protection scope of this utility model.

Claims

1. A small-dose needle-free injector, characterized in that, include: The gun body has an firing chamber and a control valve; An adjusting rod device is provided at one end of the excitation chamber; A push pin is disposed in the excitation chamber. The push pin includes a striking head and a striking pin. The striking head is disposed at one end of the striking pin near the adjusting rod device. The end face of the striking head, the inner wall of the excitation chamber, and the surface of the adjusting rod device form a pushing chamber. The pushing chamber is connected to a control valve. The striking head is provided with a guide portion along the outer periphery of the striking pin. A front cover is located at the other end of the excitation chamber. The front cover has a firing pin through hole, through which the firing pin passes and extends outward. A guide groove is provided along the outer periphery of the firing pin through hole, and the guide part can extend into the guide groove. An elastic element is provided between the bottom of the guide groove and the firing pin head.

2. The needle-free injector as described in claim 1, characterized in that, The side of the firing pin head facing the firing pin is provided with a guide sleeve, and the guide part is provided on the guide sleeve; The guide sleeve has a travel cavity on the side near the firing pin head. The firing pin extends through the travel cavity toward the front cover and can slide along the travel cavity.

3. The needle-free injector as described in claim 2, characterized in that, The firing pin is provided with a first sealing ring at one end near the firing pin head, and the first sealing ring abuts against the inner wall of the stroke cavity; The inner wall of the firing pin through hole is provided with a second sealing ring, which abuts against the firing pin.

4. The needle-free injector as described in claim 2, characterized in that, The inner wall of the guide portion, the outer wall of the firing pin, and the extension of the firing pin through hole form a guide cavity. The guide portion is provided with a first air guide hole, which communicates with the guide cavity; The firing pin has an air passage at one end near the firing pin head, and a second air guide hole for connecting the air passage and the stroke chamber.

5. The needle-free injector as described in claim 1, characterized in that, The elastic element is a compression spring, and the compression spring is sleeved on the guide portion; One end of the compression spring is abutted or fixedly connected to the striker head, and the other end is abutted or fixedly connected to the bottom of the guide groove.

6. The needleless injector as described in claim 1 or 5, characterized in that, The bottom of the guide groove is provided with a first buffer pad; The adjusting rod device has a second buffer pad at one end near the ejector pin.

7. The needle-free injector as described in claim 1, characterized in that, The adjusting rod device includes an adjusting rod and a limiting part; The adjusting rod has an adjusting thread at the end away from the ejector pin, and the excitation chamber has an adjusting through hole at the end near the adjusting rod. The adjusting thread extends outward through the adjusting through hole and is threadedly connected to the adjusting through hole. The adjusting thread is provided with a turning part at the end of the adjusting thread outside the excitation chamber, and the adjusting rod has a limiting part at the end near the ejector pin.

8. The needle-free injector as described in claim 7, characterized in that, The excitation chamber is provided with a sealing groove, the adjustment through hole is located at the bottom of the sealing groove, and a third sealing ring is provided along the inner wall of the sealing groove, the third sealing ring abutting against the adjustment rod.

9. The needleless injector as described in claim 1, characterized in that, The side wall of the firing pin head is provided with a fourth sealing ring, which abuts against the inner wall of the excitation chamber.

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