Needleless injector

Abstract

This utility model relates to the field of medical device technology, and more particularly to a needle-free injector. The needle-free injector includes a main body, the interior of which forms an inlet chamber, an outlet chamber, and an infusion channel. A first piston is provided in the inlet chamber, connecting it to the infusion channel. A second piston is provided in the outlet chamber, connecting it to the infusion channel. The first piston unidirectionally guides the inlet chamber to the infusion channel, and the second piston unidirectionally guides the infusion channel to the outlet chamber. A first seal is provided on the end face of the first piston facing away from the infusion channel, and a second seal is provided on the end face of the second piston facing the infusion channel. A push rod is slidably connected to the end of the infusion channel away from the outlet chamber. Using this utility model, the service life of the first and second seals can be improved, eliminating the need for frequent replacement of the sealing structure and ensuring the repeatable injection efficiency of the needle-free injector.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a needleless injector. Background Technology

[0002] A needle-free injector is a medical device that uses the principle of high-pressure jet to instantly inject drugs in liquid or powder form under the skin without the need for traditional needle puncture, thus eliminating the pain of needle pricks for patients.

[0003] Needle-free injectors typically use a power mechanism to drive a plunger to move at high speed in a straight line, thereby creating suction inside the injector. This opens the piston of the inlet tube and closes the piston of the outlet tube, completing the inlet action. Subsequently, the plunger quickly pushes the liquid into the outlet tube, opening the piston of the outlet tube and closing the piston of the inlet tube, completing the outlet action and injecting the liquid. After injection, the plunger is reset.

[0004] During the opening and closing of the piston, the sealing structure on the side of the piston is always in contact with the inner wall of the syringe. During repeated injections, the sealing structure is prone to failure due to friction, which leads to leakage in the needle-free syringe. Therefore, the sealing structure needs to be replaced frequently, affecting the injection efficiency. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a needle-free injector that can improve the service life of the first and second seals, eliminate the need for frequent replacement of the sealing structure, and ensure the repeatable injection efficiency of the needle-free injector.

[0006] To solve the above-mentioned technical problems, this utility model provides a needle-free injector, including a main body, wherein the interior of the main body forms an inlet chamber, an outlet chamber and an infusion channel;

[0007] The inlet chamber is equipped with a first piston, which is connected to the infusion channel via the first piston; the outlet chamber is equipped with a second piston, which is connected to the infusion channel via the second piston; and the first piston unidirectionally guides the inlet chamber to the infusion channel; the second piston unidirectionally guides the infusion channel to the outlet chamber.

[0008] The first piston has a first sealing element on its end face away from the infusion channel, and the second piston has a second sealing element on its end face facing the infusion channel.

[0009] A push rod is slidably connected to the end of the infusion channel away from the outlet chamber.

[0010] As an improvement to the above solution, a first sealing groove is provided on the end face of the first piston away from the infusion channel, and the first sealing element is engaged in the first sealing groove.

[0011] The second piston has a second sealing groove on its end face facing the infusion channel, and the second seal is engaged in the second sealing groove.

[0012] As an improvement to the above solution, the first sealing groove surrounds the outlet of the inlet chamber, and the second sealing groove surrounds the outlet of the delivery channel.

[0013] As an improvement to the above solution, the first piston has a first notch formed on its outer peripheral surface away from the infusion channel, and a first liquid passage hole is formed in the middle of the first piston; the second piston has a second notch formed on its outer peripheral surface near the infusion channel, and a second liquid passage hole is formed in the middle of the second piston.

[0014] When the main body absorbs liquid, the liquid inlet chamber is connected to the liquid delivery channel through the first notch and the first liquid passage hole;

[0015] During the main body injection, the infusion channel communicates with the outlet chamber through the second notch and the second liquid passage.

[0016] As an improvement to the above solution, the first piston forms a first limiting surface near the outer peripheral surface of the infusion channel, the first limiting surface slides in contact with the inner wall surface of the infusion channel, and the first limiting surface and the inner wall surface of the infusion channel form a clearance fit.

[0017] The second piston forms a second limiting surface on its outer peripheral surface away from the infusion channel. The second limiting surface slides in contact with the inner wall surface of the outlet cavity, and the second limiting surface and the inner wall surface of the outlet cavity form a clearance fit.

[0018] As an improvement to the above solution, a first reset member is provided on the side of the first piston facing the infusion channel, and a first stepped surface is formed on the inner wall surface of the infusion channel, and the first reset member abuts against the first stepped surface.

[0019] A second reset member is provided on the side of the second piston away from the infusion channel, and a second stepped surface is formed on the inner wall surface of the infusion chamber, and the second reset member abuts against the second stepped surface.

[0020] As an improvement to the above solution, the main body is formed with an extension tube, and the first piston is disposed inside the extension tube; the extension tube is connected to a liquid inlet connector, the liquid inlet chamber is located inside the liquid inlet connector, and the side of the liquid inlet connector facing the extension tube is sealed and abutted against the first sealing member.

[0021] As an improvement to the above solution, a connecting groove is formed at the first end of the main body, the connecting groove is connected to a needleless injection head, and the liquid outlet chamber is located inside the needleless injection head;

[0022] The second piston is disposed in the connecting groove, and the outlet of the infusion channel is formed on the bottom wall of the connecting groove, and the second seal is sealed and abutted against the bottom wall of the connecting groove.

[0023] As an improvement to the above solution, a liquid-pushing groove is formed at the second end of the main body, the liquid-pushing rod is slidably connected to the liquid-pushing groove, and the liquid-pushing rod is sealed to the liquid-pushing groove.

[0024] As an improvement to the above solution, the axis of the liquid pushing groove is on the same straight line as the axis of the liquid delivery channel, and the diameter of the liquid pushing groove is larger than the diameter of the liquid delivery channel.

[0025] Implementing this utility model has the following beneficial effects:

[0026] The needleless injector of this embodiment can draw the drug solution from the inlet chamber into the infusion channel by repeatedly pushing and pulling the push rod, and push the drug solution from the infusion channel into the outlet chamber, thus completing the repeated injection action of the needleless injector.

[0027] During repeated injections with the needle-free injector, the first seal is located on the end face of the first piston away from the infusion channel, while the second seal is located on the end face of the second piston facing the infusion channel. This means that neither the first nor the second seal slides against the inner wall of the infusion channel during the movement of the first and second pistons. Therefore, the first and second seals are not subjected to lateral friction from the inner wall of the infusion channel, thus preventing sliding friction wear during repeated piston movements. This extends the lifespan of the first and second seals, eliminating the need for frequent replacement of the sealing structure and ensuring the repeated injection efficiency of the needle-free injector. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the front view of a needleless injector according to an embodiment of the present invention;

[0029] Figure 2 This is an exploded structural diagram of a needle-free injector according to one embodiment of the present invention;

[0030] Figure 3 This is a cross-sectional view of a needleless injector according to one embodiment of the present invention;

[0031] Figure 4 This is a flow diagram of the drug solution during drug aspiration using a needleless syringe in one embodiment of this utility model, wherein the arrow indicates the direction of drug aspiration into the infusion channel;

[0032] Figure 5 This is a flow diagram of the drug solution during injection by a needleless injector in one embodiment of the present invention, wherein the arrow indicates the direction in which the drug solution is discharged from the outlet chamber;

[0033] Figure 6 This is a cross-sectional structural schematic diagram of the main body in one embodiment of the present invention;

[0034] Figure 7 This is a cross-sectional view of the first piston or the second piston in one embodiment of the present invention;

[0035] Figure 8 yes Figure 3 Enlarged view of point A in the middle;

[0036] Figure 9 yes Figure 3 Enlarged diagram of point B in the middle. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this utility model clearer, the following will describe this utility model in further detail with reference to the accompanying drawings. It is hereby declared that the terms "up," "down," "left," "right," "front," "back," "inner," and "outer," etc., appearing or about to appear in this document, are based solely on the accompanying drawings and are not intended to specifically limit this utility model.

[0038] In one embodiment of this utility model, such as Figures 1 to 3 As shown, the needle-free injector includes a main body 1, which has an inlet chamber 11, an outlet chamber 12, and an infusion channel 13. The inlet chamber 11 is equipped with a first piston 21, which connects the inlet chamber 11 to the infusion channel 13. The outlet chamber 12 is equipped with a second piston 22, which connects the outlet chamber 12 to the infusion channel 13. The first piston 21 unidirectionally guides the inlet chamber 11 to the infusion channel 13, and the second piston 22 unidirectionally guides the infusion channel 13 to the outlet chamber 12. A first seal 211 is provided on the end face of the first piston 21 facing away from the infusion channel 13, and a second seal 221 is provided on the end face of the second piston 22 facing the infusion channel 13. A push rod 14 is slidably connected to the end of the infusion channel 13 away from the outlet chamber 12.

[0039] The needleless injector of this embodiment can draw the drug solution from the inlet chamber 11 into the infusion channel 13 by repeatedly pushing and pulling the push rod 14, and push the drug solution from the infusion channel 13 into the outlet chamber 12, thus completing the repeated injection action of the needleless injector.

[0040] During repeated injections with the needle-free injector, since the first seal 211 is located on the end face of the first piston 21 facing away from the infusion channel 13, and the second seal 221 is located on the end face of the second piston 22 facing the infusion channel 13, neither the first seal 211 nor the second seal 221 slides into contact with the inner wall of the infusion channel 13 during the movement of the first piston 21 and the second piston 22. Therefore, the first seal 211 and the second seal 221 are not subjected to lateral frictional forces applied by the inner wall of the infusion channel 13, thereby avoiding sliding friction wear on the first seal 211 and the second seal 221 during repeated movements of the first piston 21 and the second piston 22. This improves the service life of the first seal 211 and the second seal 221, eliminating the need for frequent replacement of the sealing structure and ensuring the repeated injection efficiency of the needle-free injector.

[0041] Specifically, such as Figure 3 As shown, when the needleless injector is not working, the first piston 21 can disconnect the inlet chamber 11 from the infusion channel 13, and the second piston 22 can disconnect the infusion channel 13 from the outlet chamber 12, so that the infusion channel 13 does not come into contact with the external environment.

[0042] like Figure 4 As shown, when the needleless injector draws liquid, the hydraulic rod can be pulled away from the outlet chamber 12, creating a negative pressure environment in the infusion channel 13 and applying a negative pressure suction force towards the push rod 14 to the first piston 21 and the second piston 22. At this time, under the action of the internal and external pressure difference, the first piston 21 moves towards the infusion chamber, connecting the inlet chamber 11 with the infusion channel 13. At the same time, the second piston 22 blocks the infusion channel 13 and the outlet chamber 12, keeping the infusion channel 13 disconnected from the outlet chamber 12, so that the medicine can be drawn from the inlet chamber 11 into the infusion channel 13.

[0043] like Figure 5 As shown, after the liquid aspiration is completed, the hydraulic rod is pushed towards the outlet chamber 12. The medication in the infusion channel 13 pushes the first piston 21 and the second piston 22, moving them away from the push rod 14. At this time, under the fluid pressure of the infusion channel 13, the first piston 21 re-seals the inlet chamber 11, while the second piston 22 connects the infusion channel 13 and the outlet chamber 12, allowing the medication to flow from the infusion channel 13 to the outlet chamber 12, thus completing the medication injection of the needle-free injector.

[0044] In some alternative embodiments, such as Figure 3 and Figure 7As shown, the end face of the first piston 21 facing away from the infusion channel 13 is provided with a first sealing groove 212, and the first sealing element 211 is engaged in the first sealing groove 212; the end face of the second piston 22 facing the infusion channel 13 is provided with a second sealing groove 222, and the second sealing element 221 is engaged in the second sealing groove 222. The first sealing groove 212 and the second sealing groove 222 provide installation positions for the first sealing element 211 and the second sealing element 221, respectively, ensuring the ease and stability of installation of the first sealing element 211 and the second sealing element 221. Furthermore, it ensures that the first sealing element 211 and the second sealing element 221 only bear axial pressure when in contact with the stationary end face, and do not slide relative to each other when the piston moves, thus ensuring the service life of the first sealing element 211 and the second sealing element 221.

[0045] Preferably, the first sealing element 211 and the second sealing element 221 are O-rings. The good wear resistance and fatigue resistance of the O-rings reduce the wear of the sealing elements when subjected to axial pressure, and further improve the service life.

[0046] Furthermore, the first sealing groove 212 surrounds the outlet of the inlet chamber 11, and the second sealing groove 222 surrounds the outlet of the delivery channel 13, to ensure that the first sealing member 211 can seal the end wall of the first piston 21 and the outlet of the inlet chamber 11, and the second sealing member 221 can seal the end wall of the second piston 22 and the outlet of the delivery channel 13, thus ensuring the sealing performance of the first sealing member 211 and the second sealing member 221.

[0047] In some alternative embodiments, such as Figure 2 , Figure 3 and Figure 7 As shown, a first notch 213 is formed on the outer peripheral surface of the first piston 21 away from the infusion channel 13, and a first liquid passage hole 214 is formed in the middle of the first piston 21. When the main body 1 draws liquid, the inlet chamber 11 is connected to the infusion channel 13 through the first notch 213 and the first liquid passage hole 214, so that the inlet chamber 11, the first notch 213, the first liquid passage hole 214 and the infusion channel 13 are connected to form a liquid inlet channel for the drug, so that the drug in the inlet chamber 11 can be sequentially input into the infusion channel 13 through the first notch 213 and the first liquid passage hole 214 for subsequent drug injection.

[0048] The second piston 22 has a second notch 223 formed on the outer peripheral surface near the infusion channel 13, and a second liquid passage hole 224 is formed in the middle of the second piston 22. When the main body 1 injects, the infusion channel 13 is connected to the outlet chamber 12 through the second notch 223 and the second liquid passage hole 224, so that a liquid outlet channel for the drug is formed between the infusion channel 13, the second notch 223, the second liquid passage hole 224 and the outlet chamber 12, so that the drug in the infusion channel 13 can flow from the infusion channel 13 to the outlet chamber 12 under the push of the push rod 14, thus completing the drug injection of the needleless injector.

[0049] To ensure the stability of the movement of the first piston 21 and the second piston 22, such as Figure 3 and Figure 7 As shown, the first piston 21 forms a first limiting surface 215 on the outer peripheral surface near the infusion channel 13. The first limiting surface 215 slides in contact with the inner wall surface of the infusion channel 13, and a clearance fit is formed between the first limiting surface 215 and the inner wall surface of the infusion channel 13. The second piston 22 forms a second limiting surface 225 on the outer peripheral surface away from the infusion channel 13. The second limiting surface 225 slides in contact with the inner wall surface of the outlet cavity 12, and a clearance fit is formed between the second limiting surface 225 and the inner wall surface of the outlet cavity 12.

[0050] Furthermore, by utilizing the first limiting surface 215 to cooperate with the inner wall surface of the infusion channel 13, it is ensured that the first piston 21 remains coaxial with the infusion channel 13 when it moves repeatedly within the infusion channel 13; by utilizing the second limiting surface 225 to cooperate with the inner wall surface of the outlet chamber 12, it is ensured that the second piston 22 remains coaxial with the outlet chamber 12 when it moves repeatedly within the outlet chamber 12; thereby effectively ensuring the directionality of the movement of the first piston 21 and the second piston 22, avoiding eccentric movement of the first piston 21 and the second piston 22, and ensuring the stability of the first piston 21 and the second piston 22 when they move repeatedly.

[0051] In some alternative embodiments, such as Figure 3 , Figure 8 and Figure 9 As shown, a first reset member 23 is provided on the side of the first piston 21 facing the infusion channel 13, and a first stepped surface 131 is formed on the inner wall surface of the infusion channel 13, with the first reset member 23 abutting against the first stepped surface 131; a second reset member 24 is provided on the side of the second piston 22 away from the infusion channel 13, and a second stepped surface 121 is formed on the inner wall surface of the outlet chamber 12, with the second reset member 24 abutting against the second stepped surface 121. Preferably, the first reset member 23 and the second reset member 24 are compression springs.

[0052] When the main body 1 draws in liquid, the elastic force of the second reset member 24 on the second piston 22, combined with the pressure difference between the inside and outside of the second piston 22, enhances the sealing pressure applied by the second piston 22 to the second seal member 221, ensuring the sealing effect of the second piston 22 on the infusion channel 13 and the outlet chamber 12. When the main body 1 injects medication, the elastic force of the first reset member 23 on the first piston 21, combined with the liquid pressure of the medication on the first piston 21, enhances the sealing pressure applied by the first piston 21 to the first seal member 211, ensuring the sealing effect of the first piston 21 on the inlet chamber 11 and the infusion channel 13.

[0053] In some alternative embodiments, such as Figure 1 , Figure 2 and Figure 6 As shown, the main body 1 has an extension tube 15, and a first piston 21 is disposed inside the extension tube 15. The extension tube 15 is connected to a liquid inlet connector 151, and the liquid inlet chamber 11 is located inside the liquid inlet connector 151. The side of the liquid inlet connector 151 facing the extension tube 15 is sealed and abuts against the first sealing member 211. In this embodiment, the liquid inlet connector 151 is preferably a Luer connector. The liquid inlet connector 151 can communicate with an external drug source so as to deliver the drug from the external drug source to the liquid inlet chamber 11 of the liquid inlet connector 151. Connecting the external drug source to the extension tube 15 of the main body 1 through the liquid inlet connector 151 simplifies the operation of connecting or replacing the drug source and reduces the difficulty of operation.

[0054] Preferably, the Luer connector and the extension tube 15 are detachably connected by internal and external threads to facilitate replacement of the Luer connector.

[0055] Furthermore, such as Figure 1 , Figure 2 and Figure 6 As shown, a connecting groove 16 is formed at the first end of the main body 1, and a needleless injection head 161 is connected to the connecting groove 16. The liquid outlet chamber 12 is located inside the needleless injection head 161. The second piston 22 is disposed in the connecting groove 16, and the liquid outlet of the infusion channel 13 is formed on the bottom wall of the connecting groove 16. The second sealing member 221 is sealed and abutted against the bottom wall of the connecting groove 16, so as to use the micro-hole at the front end of the needleless injection head 161 to inject the drug liquid into the outside of the main body 1 in an ultra-fine, high-speed and linear manner, thereby completing the drug liquid injection of the needleless injector.

[0056] Preferably, the needleless injection head 161 is detachably connected to the connecting groove 16 via external and internal threads to facilitate the replacement of the needleless injection head 161.

[0057] In some alternative embodiments, such as Figure 3 and Figure 6As shown, a liquid-pushing groove 17 is formed at the second end of the main body 1. The liquid-pushing rod 14 is slidably connected to the liquid-pushing groove 17, and the liquid-pushing rod 14 is sealed to the liquid-pushing groove 17 to ensure that a relatively sealed environment can be formed between the infusion channel 13 and the liquid-pushing groove 17. When the liquid-pushing rod 14 moves away from the infusion channel 13, a negative pressure environment can be formed inside the infusion channel 13 due to the change in spatial volume, thereby realizing the suction of the drug solution into the infusion channel.

[0058] Specifically, the push rod 14 forms a stepped surface on the outer peripheral surface of the infusion channel 13, and a sealing ring is fitted on the stepped surface to seal the push rod 14 and the push groove 17, so as to prevent the medicine from leaking from the connection gap between the push rod 14 and the push groove 17 when the push rod 14 slides relative to the push groove 17.

[0059] Furthermore, such as Figures 3 to 6 As shown, the axis of the pusher groove 17 is collinear with the axis of the infusion channel 13 to reduce the flow resistance encountered by the liquid medicine when entering the infusion channel 13, and to reduce turbulence or eddies in the liquid medicine within the infusion channel 13. The diameter of the pusher groove 17 is larger than the diameter of the infusion channel 13, so that when the pusher rod 14 moves away from the infusion channel 13, the volume change of the infusion channel 13 increases, thereby ensuring that a negative pressure environment can be quickly formed within the infusion channel 13, increasing the suction force on the liquid medicine, and accelerating the speed at which the liquid medicine enters the infusion channel 13.

[0060] It should be noted that, for example Figure 3 As shown, the end of the push rod 14 away from the infusion channel 13 has an interface groove 141. The push rod 14 can be connected to a booster device (such as an air gun or telescopic cylinder) through the interface groove 141 so that the push rod 14 can be automatically pulled out through the booster device to complete the repeated injection action of the needleless injector.

[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 invention, and these improvements and modifications are also considered to be within the protection scope of this utility model.

Claims

1. A needle-free injector, characterized in that, The main body includes an inlet chamber, an outlet chamber, and a delivery channel. The inlet chamber is equipped with a first piston, which is connected to the infusion channel via the first piston; the outlet chamber is equipped with a second piston, which is connected to the infusion channel via the second piston; and the first piston unidirectionally guides the inlet chamber to the infusion channel; the second piston unidirectionally guides the infusion channel to the outlet chamber. The first piston has a first sealing element on its end face away from the infusion channel, and the second piston has a second sealing element on its end face facing the infusion channel. A push rod is slidably connected to the end of the infusion channel away from the outlet chamber.

2. The needle-free injector as described in claim 1, characterized in that, The first piston has a first sealing groove on its end face away from the infusion channel, and the first sealing element is engaged in the first sealing groove. The second piston has a second sealing groove on its end face facing the infusion channel, and the second seal is engaged in the second sealing groove.

3. The needle-free injector as described in claim 2, characterized in that, The first sealing groove surrounds the outlet of the inlet chamber, and the second sealing groove surrounds the outlet of the delivery channel.

4. The needle-free injector as described in claim 1, characterized in that, The first piston has a first notch formed on its outer peripheral surface away from the infusion channel, and a first liquid passage hole formed in the middle of the first piston; the second piston has a second notch formed on its outer peripheral surface near the infusion channel, and a second liquid passage hole formed in the middle of the second piston; When the main body absorbs liquid, the liquid inlet chamber is connected to the liquid delivery channel through the first notch and the first liquid passage hole; During the main body injection, the infusion channel communicates with the outlet chamber through the second notch and the second liquid passage.

5. The needle-free injector as described in claim 4, characterized in that, The first piston forms a first limiting surface near the outer peripheral surface of the infusion channel. The first limiting surface slides in contact with the inner wall surface of the infusion channel, and the first limiting surface and the inner wall surface of the infusion channel form a clearance fit. The second piston forms a second limiting surface on its outer peripheral surface away from the infusion channel. The second limiting surface slides in contact with the inner wall surface of the outlet cavity, and the second limiting surface and the inner wall surface of the outlet cavity form a clearance fit.

6. The needle-free injector as described in claim 1, characterized in that, The first piston is provided with a first reset member on the side facing the infusion channel, and the inner wall surface of the infusion channel is formed with a first stepped surface, and the first reset member abuts against the first stepped surface; A second reset member is provided on the side of the second piston away from the infusion channel, and a second stepped surface is formed on the inner wall surface of the infusion chamber, and the second reset member abuts against the second stepped surface.

7. The needle-free injector as described in claim 1, characterized in that, The main body has an extension tube, and the first piston is disposed inside the extension tube; the extension tube is connected to a liquid inlet connector, the liquid inlet chamber is located inside the liquid inlet connector, and the side of the liquid inlet connector facing the extension tube is sealed and abutted against the first sealing element.

8. The needleless injector as described in claim 1 or 7, characterized in that, A connecting groove is formed at the first end of the main body, and a needleless injection head is connected to the connecting groove. The liquid outlet chamber is located inside the needleless injection head. The second piston is disposed in the connecting groove, and the outlet of the infusion channel is formed on the bottom wall of the connecting groove, and the second seal is sealed and abutted against the bottom wall of the connecting groove.

9. The needleless injector as described in claim 1, characterized in that, The second end of the main body is formed with a liquid-pushing groove, the liquid-pushing rod is slidably connected to the liquid-pushing groove, and the liquid-pushing rod is sealed to the liquid-pushing groove.

10. The needleless injector as described in claim 9, characterized in that, The axis of the liquid pushing groove is on the same straight line as the axis of the liquid delivery channel, and the diameter of the liquid pushing groove is larger than the diameter of the liquid delivery channel.

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