Needleless injector

Abstract

This utility model discloses a needle-free injector, relating to the field of medical device technology. The needle-free injector includes: a main body with a first cavity and a second cavity connected by a connecting tube; a piston; an injection tube connected to the main body, the injection tube having a third cavity connected to the first cavity; an injection head fitted into the second cavity; a first one-way valve located in the second cavity, allowing fluid to flow towards the injection head; and a second one-way valve located in the third cavity, allowing fluid to flow towards the first cavity. By incorporating mechanical one-way valves in the second and third cavities, bidirectional pressure adaptive sealing of the injector is achieved. Under reverse pressure, the sealing block, under the combined action of fluid pressure and spring force, presses tightly against the sealing groove, forming a rigid sealing interface, eliminating the risk of liquid backflow into the vial or air seeping into the cavity.

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] Needle-free injectors eliminate the need for needles. They are medical devices that inject liquid medications into the patient's skin, subcutaneous tissue, or muscle through a micro-hole at the tip, thus sparing the patient the pain of needle pricks.

[0003] Existing continuous needle-free injectors mostly use solenoid valves or complex multi-chamber structures to control the flow of the drug solution, which has the following drawbacks: Insufficient valve sealing: the drug solution is prone to backflow into the vial during injection, resulting in inaccurate dosage; Complex structure: the solenoid valve requires circuit control, which increases the failure rate and cost; Response delay: ordinary one-way valves are not sensitive to opening and closing when switching between negative and positive pressure, affecting the continuity of injection. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a needle-free injector that can automatically switch between liquid aspiration and injection paths, thereby improving sealing and reliability.

[0005] To address the aforementioned technical problems, this utility model provides a needle-free injector, comprising: a main body having a first cavity and a second cavity connected by a connecting tube; a piston movably disposed in the first cavity; an injection tube connected to the main body, the injection tube having a third cavity connected to the first cavity; an injection head sleeved in the second cavity; a first one-way valve disposed in the second cavity, the first one-way valve allowing fluid to flow unidirectionally towards one side of the injection head; and a second one-way valve disposed in the third cavity, the second one-way valve allowing fluid to flow unidirectionally towards one side of the first cavity; wherein, both the first and second one-way valves include a fixed sleeve and a movable rod, the fixed sleeve having a communicating sealing groove and an inlet cavity; a sealing block at the first end of the movable rod that seals with the sealing groove, and a push block at the other end of the movable rod; the push block abutting against the inner wall of the inlet cavity by a spring.

[0006] As an improvement to the above solution, the inner diameter of the sealing groove tapers from one side away from the liquid inlet chamber to the other side; the circumferential ring of the sealing block is provided with a bayonet, and a first sealing ring that mates with the sealing groove is fitted on the bayonet.

[0007] As an improvement to the above solution, the pusher is cylindrical or frustum-shaped, and the outer diameter of the pusher is clearance-fitted with the inner diameter of the liquid inlet chamber.

[0008] As an improvement to the above solution, a limiting sleeve is provided at the opening of the second cavity. The first end of the limiting sleeve is connected to the injection head, and the second end of the limiting sleeve extends into the second cavity and connects with the first one-way valve.

[0009] As an improvement to the above solution, the first one-way valve is located on the side of the second cavity near the connecting hole, and the push block of the first one-way valve abuts against the connecting hole; the limiting sleeve is provided with a guide cavity, the first end of the guide cavity is connected to the injection head, the second end of the guide cavity is connected to the sealing groove of the first one-way valve, and the connection point of the second end of the guide cavity is provided with a first slot for the sealing block to extend out.

[0010] As an improvement to the above solution, the first slot is connected to the guide cavity through an injection channel, and the inner diameter of the injection channel gradually narrows from the side near the first slot to the side near the guide cavity.

[0011] As an improvement to the above solution, the third cavity is connected to the first cavity through an inlet hole, and the second one-way valve is located on the side of the third cavity near the inlet hole; a second slot for the sealing block to extend is provided at the connection between the third cavity and the inlet hole.

[0012] As an improvement to the above solution, a connector is fixed at the inlet of the injection tube. One end of the connector extends into the third cavity and abuts against the fixed sleeve of the second one-way valve. The other end of the connector is provided with an interface for connecting a medicine bottle.

[0013] As an improvement to the above solution, the connector is provided with a liquid inlet channel, one end of which is connected to the interface, and the other end of which is connected to the liquid inlet chamber of the second one-way valve.

[0014] As an improvement to the above solution, the needleless injector also includes a top cover, and the connector is fixed to the injection tube by the top cover.

[0015] The beneficial effects of implementing this utility model are as follows:

[0016] This invention discloses a needle-free injector that achieves bidirectional pressure-adaptive sealing by incorporating mechanical one-way valves in the second and third cavities. Under reverse pressure, the sealing block, under the combined action of fluid pressure and spring force, tightly presses against the conical sealing groove, forming a rigid sealing interface and completely eliminating the risk of liquid backflow into the vial or air infiltration into the cavity. This application uses mechanical one-way valves instead of electromagnetic control valves, eliminating the need for circuit modules and external control programs. It offers fast response, with the two one-way valves automatically switching between open and closed states based on the pressure difference generated by piston movement. No additional triggering device is required, reducing the number of parts and lowering the failure rate. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the structure of a needle-free injector according to an embodiment of this application;

[0018] Figure 2 This is an exploded view of the structure of a needle-free injector according to an embodiment of this application;

[0019] Figure 3 This is a cross-sectional view of the main body and injection tube of a needleless injector according to an embodiment of this application;

[0020] Figure 4 This is a cross-sectional view of the structure of a one-way valve of a needleless injector according to an embodiment of this application;

[0021] Figure 5 This is a partial structural diagram of the second cavity of a needleless injector according to an embodiment of this application;

[0022] Figure 6 yes Figure 1 Enlarged structural diagram at point A;

[0023] Figure 7 This is a schematic diagram of liquid aspiration using a needleless injector as described in an embodiment of this application;

[0024] Figure 8 This is a schematic diagram of liquid injection using a needleless injector as described in an embodiment of this application.

[0025] The reference numerals in the attached drawings are explained as follows: 100, main body; 110, first cavity; 120, second cavity; 130, connecting pipe; 200, injection pipe; 210, third cavity; 211, second slot; 212, inlet hole; 300, piston; 400, injection head; 510, first check valve; 520, second check valve; 530, fixed sleeve; 531, sealing groove; 532, inlet chamber; 540, movable rod; 54 1. Sealing block; 542. Push block; 550. Spring; 600. Limiting sleeve; 610. Guide cavity; 620. Injection channel; 630. First slot; 700. Connector; 710. Inlet channel; 800. Top cover; 901. First sealing ring; 902. Second sealing ring; 903. Third sealing ring; 904. Fourth sealing ring; 905. Fifth sealing ring; 906. Sixth sealing ring; 907. Seventh sealing ring. Detailed Implementation

[0026] 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.

[0027] See Figures 1-3 , Figure 1 This is a cross-sectional view of the structure of a needle-free injector according to an embodiment of this application; Figure 2This is an exploded view of the structure of a needle-free injector according to an embodiment of this application; Figure 3 This is a cross-sectional view of the main body and injection tube of a needle-free injector according to an embodiment of this application. As shown in the figure, the needle-free injector includes: a main body 100, which has a first cavity 110 and a second cavity 120 connected by a connecting tube 130; a piston 300, movably disposed in the first cavity 110; an injection tube 200, connected to the main body 100, and having a third cavity 210 connected to the first cavity 110; and an injection head 400, sleeved on the first cavity 110. The second chamber 120 has a first one-way valve 510, which allows fluid to flow unidirectionally towards the injection head 400; and a second one-way valve 520, which allows fluid to flow unidirectionally towards the first chamber 110. This invention provides a needle-free injector that achieves bidirectional pressure adaptive sealing by incorporating mechanical one-way valves in the second and third chambers 120 and 210. Under reverse pressure, the sealing block 541 presses tightly against the conical sealing groove 531 under the combined action of fluid pressure and spring 550, forming a rigid sealing interface and completely eliminating the risk of liquid backflow into the vial or air infiltration into the chamber. This application uses mechanical one-way valves instead of electromagnetic control valves, eliminating the need for circuit modules and external control programs. It offers fast response, and the two one-way valves automatically switch between open and closed states based on the pressure difference generated by the piston 300's movement, eliminating the need for additional triggering devices, reducing the number of parts, and lowering the failure rate.

[0028] See Figure 2 and Figure 4 , Figure 4 This is a cross-sectional view of the structure of a one-way valve of a needleless injector according to an embodiment of this application;

[0029] Furthermore, in this embodiment, both the first one-way valve 510 and the second one-way valve 520 include a fixed sleeve 530 and a movable rod 540. The fixed sleeve 530 has a communicating sealing groove 531 and an inlet chamber 532. The first end of the movable rod 540 is provided with a sealing block 541 that cooperates with the sealing groove 531 for sealing, and the other end of the movable rod 540 is provided with a push block 542. The push block 542 abuts against the inner wall of the inlet chamber 532 through a spring 550. Under normal conditions, the push block 542 seals the inlet of the liquid inlet chamber 532 under the force of the spring 550, and the sealing block 541 seals the sealing groove 531. When the one-way valve is pushed by the fluid on one side of the push block 542, the push block 542 compresses the spring 550, and the sealing block 541 moves away from the sealing groove 531, thus opening the one-way valve. When the one-way valve is pushed by the fluid on one side of the sealing block 541, the sealing block 541 presses against the sealing groove 531, thus closing the one-way valve.

[0030] Preferably, the inner diameter of the sealing groove 531 tapers from one side away from the liquid inlet chamber 532 to the other side; the sealing block 541 has a circumferentially provided with a retaining groove, and a first sealing ring 901 that mates with the sealing groove 531 is fitted onto the retaining groove. Through the synergistic effect of the conical rigid sealing groove 531 and the elastic first sealing ring 901, breakthroughs are achieved in key indicators such as high-pressure sealing, dynamic response, and wear compensation, making it particularly suitable for extreme working conditions such as high-frequency high-pressure impact and drug corrosion in needle-free injectors.

[0031] Preferably, the conical convergence angle of the sealing groove 531 is 15° to 60°.

[0032] Preferably, the pusher block 542 is cylindrical or frustum-shaped, and the outer diameter of the pusher block 542 is clearance-fitted with the inner diameter of the liquid inlet chamber 532.

[0033] See Figure 5 , Figure 5 This is a partial structural diagram of the second cavity 120 of a needleless injector according to an embodiment of this application.

[0034] Furthermore, in this embodiment, a limiting sleeve 600 is provided at the opening of the second cavity 120. The first end of the limiting sleeve 600 is connected to the injection head 400, and the second end of the limiting sleeve 600 extends into the second cavity 120 and is connected to the first one-way valve 510.

[0035] See Figure 5 Furthermore, in this embodiment, the first one-way valve 510 is located on the side of the second cavity 120 near the connecting hole, and the push block 542 of the first one-way valve 510 abuts against the connecting hole; the limiting sleeve 600 is provided with a guide cavity 610, the first end of the guide cavity 610 is connected to the injection head 400, and the second end of the guide cavity 610 is connected to the sealing groove 531 of the first one-way valve 510. The connection point of the second end of the guide cavity 610 is provided with a first slot 630 for the sealing block 541 to extend out. When the first one-way valve 510 is opened, the sealing block 541 in the first one-way valve 510 is precisely inserted into the first slot-limited space to prevent excessive displacement from causing uneven wear of the sealing ring or leakage inside the valve.

[0036] See Figure 5 Furthermore, in this embodiment, the first slot 630 is connected to the guide cavity 610 via an injection channel 620, and the inner diameter of the injection channel 620 gradually narrows from the side near the first slot 630 to the side near the guide cavity 610. By setting the tapered injection channel 620, the liquid flowing out of the first one-way valve 510 is pressurized a second time, increasing the flow rate of the liquid and preventing the liquid from sticking together.

[0037] See Figure 3 and Figure 6 , Figure 6 yes Figure 1 Enlarged structural diagram at point A;

[0038] Furthermore, in this embodiment, the third cavity 210 is connected to the first cavity 110 through the liquid inlet hole 212, and the second one-way valve 520 is located on the side of the third cavity 210 near the liquid inlet hole 212; a second slot 211 is provided at the connection between the third cavity 210 and the liquid inlet hole 212 for the sealing block 541 to extend out.

[0039] See Figure 6 Furthermore, in this embodiment, a connector 700 is fixed at the inlet of the injection tube 200. One end of the connector 700 extends into the third cavity 210 and abuts against the fixing sleeve 530 of the second one-way valve 520. The other end of the connector 700 is provided with an interface for connecting a medicine bottle. Specifically, the connector 700 is provided with an inlet channel 710. One end of the inlet channel 710 is connected to the interface, and the other end of the inlet channel 710 is connected to the inlet chamber 532 of the second one-way valve 520.

[0040] Furthermore, in this embodiment, the needleless injector also includes a top cover 800, and the connector 700 is fixed to the injection tube 200 through the top cover 800.

[0041] Preferably, the push rod is connected to the booster device.

[0042] See Figure 2 , Figure 5 and Figure 6 Furthermore, in this embodiment, a second sealing ring 902 is provided between the limiting sleeve 600 and the inner wall of the injection head 400; a third sealing ring 903 is provided between the limiting sleeve 600 and the inner wall of the second cavity 120; a fourth sealing ring 904 is provided between the outer wall of the first one-way valve 510 and the inner wall of the second cavity 120; a fifth sealing ring 905 is provided between the outer wall of the second one-way valve 520 and the inner wall of the third cavity 210; a sixth sealing ring 906 is provided between the connector 700 and the inner wall of the third cavity 210; and a seventh sealing ring 907 is provided between the piston 300 and the inner wall of the first cavity 110. The airtightness of the injection tube 200 is improved by the above sealing rings, ensuring that the liquid flows in the specified direction.

[0043] Figure 7 This is a schematic diagram of liquid aspiration using a needleless injector as described in an embodiment of this application;

[0044] Furthermore, this embodiment provides a liquid aspiration method using a needle-free injector, including the following steps:

[0045] Connect the medicine bottle to connector 700;

[0046] The piston 300 rod is driven by a booster device to move away from the second chamber 120.

[0047] The first one-way valve 510 inside the second cavity 120 remains sealed under the action of vacuum suction;

[0048] The second one-way valve 520 in the third cavity 210 compresses the spring 550 under the action of vacuum suction, and the sealing block 541 enters the second slot 211 under the action of thrust. The one-way valve opens, and the liquid in the medicine bottle flows into the first cavity 110 through the liquid inlet channel 710, the second one-way valve 520 and the liquid inlet hole 212 in sequence, completing the liquid suction.

[0049] Figure 8 This is a schematic diagram of liquid injection using a needleless injector as described in an embodiment of this application.

[0050] Furthermore, this embodiment provides a liquid injection method using a needle-free injector, including the following steps:

[0051] The piston 300 rod is driven by a booster device to move away from the second chamber 120.

[0052] Part of the liquid medicine enters the third chamber 210 and closes the one-way valve in the third chamber 210;

[0053] The remaining liquid medicine enters the second cavity 120 through the connecting pipe 130. The one-way valve in the second cavity 120 compresses the spring 550 under the action of hydraulic pressure. The sealing block 541 enters the first slot 630 under the action of thrust. The first one-way valve 510 opens, and the liquid medicine flows into the guide cavity 610 through the one-way valve, and then enters the injection head 400 through the guide cavity 610 for injection, thus completing the injection.

[0054] As can be seen from the above, the needle-free injector of this utility model achieves bidirectional pressure adaptive sealing by setting unique mechanical one-way valves in the second and third cavities. Under the action of reverse pressure, the sealing block presses tightly against the conical sealing groove under the dual action of fluid pressure and spring force, forming a rigid sealing interface, completely eliminating the risk of liquid backflow into the medicine bottle or air seeping into the cavity. This application uses mechanical one-way valves instead of electromagnetic control valves, eliminating the need for circuit modules and external control programs, resulting in fast response speed. The two one-way valves automatically switch between open and closed states through the pressure difference generated by piston movement, eliminating the need for additional triggering devices, reducing the number of parts, and lowering the failure rate.

[0055] 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 needle-free injector, characterized in that, include: The main body has a first cavity and a second cavity connected by a connecting pipe. A piston is movably disposed in the first cavity; The injection tube is connected to the main body, and the injection tube has a third cavity that communicates with the first cavity. The injection head is fitted onto the second cavity; A first check valve is disposed in the second cavity, which allows fluid to flow unidirectionally to one side of the injection head; A second check valve is disposed in the third cavity, and the second check valve allows fluid to flow unidirectionally to one side of the first cavity; The first and second check valves each include a fixed sleeve and a movable rod. The fixed sleeve has a communicating sealing groove and a liquid inlet chamber. The first end of the movable rod has a sealing block that cooperates with the sealing groove to seal, and the other end of the movable rod has a push block. The push block abuts against the inner wall of the liquid inlet chamber through a spring.

2. The needle-free injector according to claim 1, characterized in that, The inner diameter of the sealing groove tapers from one side away from the liquid inlet chamber to the other side; the sealing block has a circumferentially ringed with a retainer, and a first sealing ring that mates with the sealing groove is fitted onto the retainer.

3. A needle-free injector according to claim 1, characterized in that, The pusher is cylindrical or frustum-shaped, and its outer diameter is clearance-fitted with the inner diameter of the liquid inlet chamber.

4. A needle-free injector according to claim 1, characterized in that, A limiting sleeve is provided at the opening of the second cavity. The first end of the limiting sleeve is connected to the injection head, and the second end of the limiting sleeve extends into the second cavity and is connected to the first one-way valve.

5. A needle-free injector according to claim 4, characterized in that, The first check valve is located on the side of the second cavity near the connecting hole, and the push block of the first check valve abuts against the connecting hole; The limiting sleeve has a guide cavity. The first end of the guide cavity is connected to the injection head, and the second end of the guide cavity is connected to the sealing groove of the first one-way valve. The connection point of the second end of the guide cavity is provided with a first slot for the sealing block to extend out.

6. A needle-free injector according to claim 5, characterized in that, The first slot is connected to the guide cavity through an injection channel, and the inner diameter of the injection channel gradually narrows from the side near the first slot to the side near the guide cavity.

7. A needle-free injector according to claim 1, characterized in that, The third cavity is connected to the first cavity through an inlet hole, and the second one-way valve is located on the side of the third cavity near the inlet hole; a second slot is provided at the connection between the third cavity and the inlet hole for the sealing block to extend out.

8. A needle-free injector according to claim 1, characterized in that, A connector is fixed at the inlet of the injection tube. One end of the connector extends into the third cavity and abuts against the fixed sleeve of the second one-way valve. The other end of the connector is provided with an interface for connecting a medicine bottle.

9. A needle-free injector according to claim 8, characterized in that, The connector is provided with a liquid inlet channel. One end of the liquid inlet channel is connected to the interface, and the other end of the liquid inlet channel is connected to the liquid inlet chamber of the second one-way valve.

10. A needle-free injector according to claim 8, characterized in that, The needleless injector also includes a top cover, and the connector is fixed to the injection tube by the top cover.

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