A needle-free syringe

Abstract

The present invention relates to the technical field of syringes, and in particular to a needle-free syringe, comprising an injection mechanism and a firing assembly, wherein the injection mechanism comprises a piston cylinder and a piston assembly which is slidably arranged in the piston cylinder to push out a medicine liquid in the piston cylinder for injection, and the assembly comprises an inner sleeve, a sleeve assembly threadedly connected to the inner sleeve, a button sleeve sleeved outside the sleeve assembly and circumferentially fixed to the inner sleeve, a clamping mechanism, a first elastic member arranged between the sleeve assembly and the piston assembly, and a second elastic member arranged between the piston assembly and the clamping mechanism; the present invention utilizes the sleeve assembly to move forward to drive the clamping mechanism to lock the piston assembly, and to move backward to drive the piston assembly to suck the medicine liquid, and utilizes the button sleeve sleeved outside the sleeve assembly to realize the grip and firing of the syringe, and there is no need to press the firing button separately when holding the syringe, thereby facilitating the use of the syringe.

Description

Technical Field

[0001] The present invention relates to the technical field of syringes, in particular to a needle-free syringe. Background Art

[0002] The needle-free syringe usually includes a piston assembly and a firing assembly. The firing assembly pressurizes the liquid medicine through the piston assembly, so that the liquid medicine is ejected at high speed through the spray hole to form a jet, penetrating the human epidermis to reach the subcutaneous tissue.

[0003] The needle-free syringe in the prior art is usually provided with a firing button at the end thereof. During operation, the operator first grasps the needle-free syringe, places it against the injection site, and then presses the firing button to perform the injection. That is to say, the operator needs to press the firing button while grasping the needle-free syringe, which may cause inconvenience in operation and even unstable grip, resulting in injection failure. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in order to solve the problem that the needle-free syringe in the prior art needs to press the firing button while grasping the needle-free syringe, which causes inconvenience in operation and even unstable grip, resulting in injection failure, a needle-free syringe is now provided.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: a needle-free syringe, comprising:

[0006] The injection mechanism comprises a piston cylinder and a piston assembly slidably disposed in the piston cylinder to push out the liquid medicine in the piston cylinder to implement the injection;

[0007] and a firing assembly, comprising an inner sleeve, a sliding sleeve assembly threadedly connected to the inner sleeve, a button sleeve sleeved outside the sliding sleeve assembly and circumferentially fixed thereto, a clamping mechanism, a first elastic member disposed between the sliding sleeve assembly and the piston assembly, and a second elastic member disposed between the piston assembly and the clamping mechanism;

[0008] The sleeve assembly has a first position and a second position along its axial direction. The clamping mechanism is used to lock the piston assembly on the sleeve assembly after the sleeve assembly overcomes the elastic force of the first elastic member and moves from the first position to the second position. During the movement of the sleeve assembly from the second position to the first position, the clamping mechanism drives the piston assembly to move away from the piston cylinder to suck the medicine. When the button sleeve is pressed, the clamping mechanism pushes the piston assembly away from the sleeve assembly, so that the piston assembly can be injected under the action of the first elastic member.

[0009] Further, the clamping mechanism comprises at least two steel balls embedded in the sliding sleeve assembly along the circumferential direction and arranged in a floating manner, a locking groove located on the piston assembly for the steel balls to be embedded in to lock the piston assembly, and an unlocking sleeve provided with an unlocking groove for the steel balls to be embedded in to unlock the piston assembly, and the sliding sleeve assembly is provided with a floating groove for the steel balls to be embedded in;

[0010] When the sliding sleeve assembly moves from the first position to the second position, the steel ball gradually slides out of the unlocking groove and enters the locking groove of the piston assembly under the push of the inner peripheral wall of the unlocking sleeve to lock the piston assembly;

[0011] When the button sleeve drives the unlocking sleeve to move toward the direction of the piston assembly until the unlocking groove is opposite to the floating groove, the unlocking sleeve overcomes the elastic force of the second elastic member and pushes the piston assembly so that the steel ball in the locking groove disengages from the locking groove and enters the unlocking groove to release the lock of the piston assembly.

[0012] Furthermore, it also includes a safety mechanism, which is used to prevent the clamping mechanism from releasing the clamping of the piston assembly during the process of the piston assembly sucking the medicine liquid.

[0013] Furthermore, the safety mechanism includes a safety knob, a safety ring circumferentially fixed to the safety knob and having a safety cavity therein, a limiting sleeve sleeved outside the unlocking sleeve and matching the shape of the safety cavity, and a third elastic member arranged between the safety knob and the button sleeve to drive the safety knob to reset;

[0014] When the safety knob drives the safety ring to rotate until the safety cavity is directly opposite to the limiting sleeve, the safety cavity allows the limiting sleeve to pass through to unlock the piston assembly.

[0015] Furthermore, the sliding sleeve assembly includes a center ring sleeve threadedly connected to the inner sleeve, a transition sleeve axially fixed to the center ring sleeve, and a fixed sleeve fixed to the transition sleeve and provided with the above-mentioned floating groove, and the unlocking sleeve is located between the fixed sleeve and the transition sleeve.

[0016] Furthermore, a pushing sleeve is slidably provided at one end of the fixing sleeve away from the piston assembly, and the second elastic member is located between the unlocking sleeve and the pushing sleeve.

[0017] Furthermore, the center ring sleeve includes an inner ring and an outer ring, the inner sleeve is arranged between the inner ring and the outer ring and is threadedly connected to the inner ring, the end of the outer ring close to the piston cylinder is connected to a lens sleeve, a lens is installed in the lens sleeve and a pressure block is pressed on the outside of the lens to press the lens into the lens sleeve.

[0018] Furthermore, a fourth elastic member is provided between the unlocking sleeve and the transition sleeve.

[0019] Furthermore, an end cover is formed at one end of the button sleeve away from the piston cylinder, and a positioning groove is protruded from the inner wall of the end cover for the limiting sleeve to be inserted into so as to limit its circumference.

[0020] Furthermore, a limiting mechanism for axially limiting the button sleeve and the sliding sleeve assembly is provided between the button sleeve and the sliding sleeve assembly, and the limiting mechanism includes a limiting groove formed by a depression on the inner peripheral wall of the button sleeve and a limiting protrusion protruding from the outer peripheral wall of the sliding sleeve assembly.

[0021] The beneficial effects of the present invention are as follows: the present invention utilizes the sliding sleeve assembly to move forward to drive the clamping mechanism to lock the piston assembly, and moves backward to drive the piston assembly to draw liquid medicine, and utilizes a button sleeve mounted on the outside of the sliding sleeve assembly to realize the grasping and firing of the syringe. There is no need to press the firing button separately when holding the syringe, which facilitates the use of the syringe. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0023] Figure 1 is a three-dimensional schematic diagram of the present invention;

[0024] Figure 2 is a schematic diagram of the present invention in a state where the firing is completed and the pressurization is to be performed (i.e., a schematic diagram of a state where the slide assembly is in the first position);

[0025] Figure 3 yes Figure 2 A partial enlarged view of part A;

[0026] Figure 4 is a schematic diagram of the present invention in a state where pressurization is completed and liquid is ready to be absorbed (i.e., a schematic diagram of a state where the sliding sleeve assembly is located in the second position);

[0027] Figure 5 yes Figure 4 A partial enlarged view of part B;

[0028] Figure 6 is a schematic diagram of the state of the present invention in which the liquid aspiration is completed and the firing is ready (i.e., a schematic diagram of the state in which the sliding sleeve assembly returns from the second position to the first position);

[0029] Figure 7 yes Figure 6 A partial enlarged view of part C;

[0030] Figure 8 It is an exploded diagram of the insurance organization;

[0031] Fig. 9 This is an exploded view of the sleeve assembly.

[0032] In the figure:

[0033] 1. Piston cylinder;

[0034] 2. Piston assembly; 201. Locking groove;

[0035] 3. Inner sleeve;

[0036] 4. Sliding sleeve assembly; 401. Floating groove; 402. Center ring sleeve; 4021. Inner ring; 4022. Outer ring; 4023. Limiting protrusion; 403. Transition sleeve; 404. Fixed sleeve; 405. Lens sleeve; 406. Lens; 407. Press block;

[0037] 5. button sleeve; 501. end cover; 5011. positioning groove;

[0038] 6. Clamping mechanism; 601. Steel ball; 602. Unlocking sleeve; 6021. Unlocking groove; 603. Pushing sleeve;

[0039] 7. a first elastic member;

[0040] 8. A second elastic member;

[0041] 9. Safety mechanism; 901. Safety knob; 9011. Knob portion; 9012. Sleeve portion; 902. Safety ring; 9021. Safety cavity; 9022. Third installation cavity; 9023. First slot; 903. Limiting sleeve; 904. Third elastic member;

[0042] 10. Fourth elastic member. DETAILED DESCRIPTION

[0043] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner only, and therefore only show the components related to the present invention, and directions and references (e.g., up, down, left, right, etc.) may only be used to help describe the features in the drawings. Therefore, the following specific embodiments are not to be taken in a limiting sense, and the scope of the subject matter claimed is limited only by the attached claims and their equivalents.

[0044] like Figure 1 As shown, a needle-free syringe includes an injection mechanism and a firing assembly;

[0045] The injection mechanism includes a piston cylinder 1 and a piston assembly 2 which is slidably arranged in the piston cylinder 1 to push out the liquid medicine in the piston cylinder 1 for injection. The piston cylinder 1 is provided with a spray hole for spraying the liquid medicine. The piston assembly 2 can push the liquid medicine out of the spray hole at a high speed to allow the liquid medicine to enter the skin.

[0046] and a firing assembly, comprising an inner sleeve 3, a sleeve assembly 4 threadedly connected to the inner sleeve 3, a button sleeve 5 sleeved outside the sleeve assembly 4 and circumferentially fixed thereto, a clamping mechanism 6, a first elastic member 7 disposed between the sleeve assembly 4 and the piston assembly 2, and a second elastic member 8 disposed between the piston assembly 2 and the clamping mechanism 6, wherein the first elastic member 7 and the second elastic member 8 may be springs;

[0047] The sleeve assembly 4 has a first position and a second position along its axial direction. The clamping mechanism 6 is used to lock the piston assembly 2 on the sleeve assembly 4 after the sleeve assembly 4 overcomes the elastic force of the first elastic member 7 and moves from the first position to the second position. During the movement of the sleeve assembly 4 from the second position to the first position, the clamping mechanism 6 drives the piston assembly 2 to move away from the piston cylinder 1 to suck the medicine liquid. When the button sleeve 5 is pressed, the piston assembly 2 is pushed away from the sleeve assembly 4 through the clamping mechanism 6, so that the piston assembly 2 is injected under the action of the first elastic member 7.

[0048] The button sleeve 5 and the sliding sleeve assembly 4 are connected by a key, one of which is provided with a key slot extending along its axial direction, and the other is provided with a connecting key protruding therefrom, and the connecting key cooperates with the key slot to achieve that the button sleeve 5 and the sliding sleeve assembly 4 are fixed in the circumferential direction and can move relative to each other in the axial direction;

[0049] One end of the inner sleeve 3 away from the sliding sleeve assembly 4 is fixed to the piston cylinder 1, and a first installation cavity for installing the first elastic member 7 is formed between the inner circumferential wall of the inner sleeve 3 and the outer circumferential wall of the piston assembly 2, and one end of the first elastic member 7 abuts against the piston assembly 2, and the other end abuts against the sliding sleeve assembly 4;

[0050] When working, the button sleeve 5 is first rotated in the first direction, the sliding sleeve assembly 4 rotates synchronously and moves from the first position to the second position, the first elastic member 7 is compressed, and when the sliding sleeve assembly 4 reaches the second position (such as Figure 4 and Figure 5 As shown in the figure, the clamping mechanism 6 clamps the piston assembly 2 to form a combination, and then rotates the button sleeve 5 in a second direction opposite to the first direction, and the sliding sleeve assembly 4 rotates synchronously and moves from the second position to the first position, driving the above-mentioned combination to move backward, and the piston assembly 2 gradually sucks the liquid medicine. After the liquid medicine is sucked to a predetermined dose (as shown in the figure), the piston assembly 2 gradually sucks the liquid medicine to a predetermined dose (as shown in the figure). Figure 6 and Figure 7 As shown in the figure, hold the button sleeve 5 to place the syringe against the injection site, then press the button sleeve 5 toward the injection site, the button sleeve 5 drives the clamping mechanism 6 to move in the direction of the piston assembly 2 to apply pressure to the piston assembly 2 to push it away from the sliding sleeve assembly 4, at this time the first elastic member 7 is reset, and the piston assembly 2 pushes the liquid medicine out of the spray under the elastic force of the first elastic member 7 (as shown in the figure). Figure 2 and Figure 3 shown).

[0051] In some examples, the clamping mechanism 6 includes at least two steel balls 601 circumferentially embedded in the sleeve assembly 4 and arranged in a floating manner, a locking groove 201 located on the piston assembly 2 for the steel ball 601 to be embedded in order to lock the piston assembly 2, and an unlocking sleeve 602 provided with an unlocking groove 6021 for the steel ball 601 to be embedded in order to unlock the piston assembly 2. The locking groove 201 and the unlocking groove 6021 are both annular grooves. The sleeve assembly 4 is provided with a floating groove 401 for the steel ball 601 to be embedded. The steel balls 601 correspond to the floating grooves 401 one by one and each steel ball 601 is embedded in its corresponding floating groove 401. The number may be but is not limited to two, three or four, etc. The unlocking groove 6021 is provided with guide slopes at both ends along its axial direction to facilitate the steel ball 601 to slide in and out.

[0052] like Figure 3 As shown, when the sleeve assembly 4 is located at the first position, the unlocking groove 6021 is opposite to the floating groove 401, and the steel ball 601 is embedded in the two. When the sleeve assembly 4 moves to the second position, the floating groove 401 and the unlocking groove 6021 are staggered, and the piston assembly 2 is gradually inserted into the sleeve assembly 4, and the steel ball 601 gradually slides out of the unlocking groove 6021. When the locking groove 201 is opposite to the floating groove 401, the steel ball 601 enters the locking groove 201 of the piston assembly 2 under the push of the inner circumferential wall of the unlocking sleeve 602 to lock the piston assembly 2. At this time, the steel ball 601 is located inside the locking groove 201 and the floating groove 401, as shown in FIG. Figure 5 As shown;

[0053] When the button sleeve 5 drives the unlocking sleeve 602 to move toward the direction of the piston assembly 2 until the unlocking groove 6021 is opposite to the floating groove 401, the unlocking sleeve 602 overcomes the elastic force of the second elastic member 8 to push the piston assembly 2, and the groove wall of the locking groove 201 applies a thrust to the steel ball 601 in the locking groove 201 to make it slide out of the locking groove 201 and enter the unlocking groove 6021 to release the lock of the piston assembly 2.

[0054] In some examples, a safety mechanism 9 is also included, which is used to prevent the clamping mechanism 6 from releasing the lock on the piston assembly 2 during the process of the piston assembly 2 sucking the liquid, thereby preventing the button sleeve 5 from being accidentally touched and causing the syringe to be fired unexpectedly.

[0055] In some examples, such as Figure 8 As shown, the safety mechanism 9 includes a safety knob 901, a safety ring 902 circumferentially fixed to the safety knob 901 and having a safety cavity 9021 therein, a limiting sleeve 903 sleeved on the outside of the unlocking sleeve 602 and matching the shape of the safety cavity 9021, and a third elastic member 904 arranged between the safety knob 901 and the button sleeve 5 to drive the safety knob 901 to reset, and the third elastic member 904 is a torsion spring;

[0056] The safety knob 901 is sleeved on the outside of the safety ring 902 and the two are connected by a key. A connection key is formed on one of the two, and a key slot is formed on the other. The safety knob 901 includes a knob portion 9011 extending out of the button sleeve 5 and a sleeve portion 9012 sleeved on the outside of the safety ring 902, and the connection key or key slot is located on the sleeve portion; the safety ring 902 is provided with a third installation cavity 9022 for installing the third elastic member 904 and a first card slot 9023 for one end of the third elastic member 904 to be inserted, and the other end of the third elastic member 904 is inserted into the second card slot on the button sleeve 5;

[0057] When the safety knob 901 drives the safety ring 902 to rotate until the safety cavity 9021 is opposite to the limiting sleeve 903, the button sleeve 5 is pressed, and the button sleeve 5 drives the limiting sleeve 903 to pass through the safety cavity 9021, so that the limiting sleeve 903 and the unlocking sleeve 602 move toward the direction of the piston assembly 2 to apply pressure to the piston assembly 2 to make it break away from the clamping of the steel ball 601.

[0058] In some examples, such as Fig. 9 As shown, the sliding sleeve assembly 4 includes a center ring sleeve 402 threadedly connected to the inner sleeve 3, a transition sleeve 403 axially fixed to the center ring sleeve 402, and a fixed sleeve 404 fixed to the transition sleeve 403 and provided with the above-mentioned floating groove 401, the unlocking sleeve 602 is located between the fixed sleeve 404 and the transition sleeve 403, and the fixed sleeve 404 and the transition sleeve 403 are both provided with a limiting step for axially limiting the unlocking sleeve 602, and a bearing is installed between the center ring sleeve 402 and the transition sleeve 403 so that when the center ring sleeve 402 rotates, the transition sleeve 403 only has an axial displacement and does not rotate with the center ring sleeve 402.

[0059] In some examples, such as Figure 3 , Figure 5 and Figure 7 As shown, a pushing sleeve 603 is slidably provided at one end of the fixing sleeve 404 away from the piston assembly 2, and the second elastic member 8 is located between the unlocking sleeve 602 and the pushing sleeve 603;

[0060] When the center ring sleeve 402 is rotated in the first direction, the center ring sleeve 402 moves from the first position to the second position, driving the transition sleeve 403 to move forward, and the fixed sleeve 404 moves synchronously, the floating groove 401 and the unlocking groove 6021 are staggered, and at the same time, the piston assembly 2 gradually enters the fixed sleeve 404 and is inserted into the pushing sleeve 603 to apply thrust to the pushing sleeve 603, and the second elastic member 8 is compressed until the floating groove 401 is aligned with the locking groove 201, and the steel ball 601 enters the locking groove 201 of the piston assembly 2 under the push of the inner circumferential wall of the unlocking sleeve 602 to lock the piston assembly 2;

[0061] Then the center ring sleeve 402 is rotated in the second direction, and the center ring sleeve 402 moves from the second position to the first position, and drives the fixed sleeve 404 to move backward synchronously through the transition sleeve 403. The fixed sleeve 404 drives the piston assembly 2 to move backward through the steel ball 601. The piston assembly 2 pushes the pushing sleeve 603, and the pushing sleeve 603 drives the unlocking sleeve 602 to move backward through the second elastic member 8 so that the inner circumferential wall of the unlocking sleeve 602 is always pressed on the notch of the floating groove 401 to confine the steel ball 601 in the floating groove 401 and the locking groove 201.

[0062] When firing, the button sleeve 5 is pressed, and the button sleeve 5 drives the unlocking sleeve 602 to move forward. The unlocking sleeve 602 applies pressure to the pushing sleeve 603 through the second elastic member 8, and the pushing sleeve 603 applies pressure to the piston assembly 2. When the unlocking groove 6021 of the unlocking sleeve 602 is opposite to the floating groove 401, the steel ball 601 is pushed by the piston assembly 2 to break away from the locking groove 201 and enter the unlocking groove 6021.

[0063] In some examples, such as 1 and Fig. 9 As shown, the center ring sleeve 402 includes an inner ring 4021 and an outer ring 4022, the inner sleeve 3 is arranged between the inner ring 4021 and the outer ring 4022 and is threadedly connected to the inner ring 4021, the end of the outer ring 4022 close to the piston cylinder 1 is connected to the lens sleeve 405 through a snap-fit ​​structure, a lens 406 is installed in the lens sleeve 405, and a pressure block 407 is pressed on the outside of the lens 406 to confine the lens 406 in the lens 406 sleeve 405, and a dosage scale is marked on the inner sleeve 3. In the process of the center ring sleeve 402 driving the piston assembly 2 to move from the second position to the first position, the piston assembly 2 gradually sucks the medicine liquid, and the operator can observe the dosage of the medicine liquid sucked by the piston assembly 2 through the lens 406.

[0064] In some examples, such as Figure 3 , Figure 5 and Figure 7 As shown, a fourth elastic member 10 is provided between the unlocking sleeve 602 and the transition sleeve 403. When the center ring sleeve 402 drives the transition sleeve 403 to move from the first position to the second position, the transition sleeve 403 drives the unlocking sleeve 602 to move forward through the fourth elastic member 10 until the transition sleeve 403 reaches the second position. The piston assembly 2 applies pressure to the unlocking sleeve 602 through the second elastic member 8 and the pushing sleeve 603, so that the unlocking groove 6021 is staggered with the floating groove 401, and the steel ball 601 is pressed into the locking groove 201.

[0065] In some examples, such as Figure 2As shown, an end cover 501 is formed at one end of the button sleeve 5 facing away from the piston cylinder 1, and a positioning groove 5011 is protruded from the inner wall of the end cover 501 for the limit sleeve 903 to be inserted into to limit its circumference, so as to prevent the limit sleeve 903 from unexpectedly rotating and being unable to face the safety cavity 9021 after the safety mechanism 9 is opened, resulting in a firing failure. The shape of the positioning groove 5011 matches the shape of the limit sleeve 903 and the safety cavity 9021, and can be but not limited to a non-circular structure such as an elliptical or square shape.

[0066] In some examples, such as Fig. 9 As shown, a limiting mechanism for axially limiting the button sleeve 5 and the sliding sleeve assembly 4 is provided between the button sleeve 5 and the sliding sleeve assembly 4. The limiting mechanism includes a limiting groove and a limiting protrusion 4023 respectively located on the button sleeve 5 and the sliding sleeve assembly 4. In this embodiment, the limiting protrusion 4023 is located on the center ring sleeve 402, and the limiting groove is located on the button sleeve 5.

[0067] Working principle:

[0068] (1) First, the button sleeve 5 is rotated in the first direction, and the center ring sleeve 402 moves from the first position to the second position (i.e., moves forward), driving the transition sleeve 403 to move forward, and the fixed sleeve 404 moves synchronously. The first elastic member 7 is compressed, and the floating groove 401 and the unlocking groove 6021 are staggered. At the same time, the piston assembly 2 gradually enters the fixed sleeve 404 and the pushing sleeve 603 and applies a thrust to the pushing sleeve 603. The second elastic member 8 is compressed, and the steel ball 601 gradually slides out of the unlocking groove 6021. When the sliding sleeve assembly 4 reaches the second position, the locking groove 201 and the floating groove 401 are opposite. The steel ball 601 enters the locking groove 201 of the piston assembly 2 under the push of the inner circumferential wall of the unlocking sleeve 602 to lock the piston assembly 2 on the sliding sleeve assembly 4. This is the pressurization process. Figure 2 is a state diagram of the sliding sleeve assembly 4 in the first position, Figure 4 The state diagram of the sleeve assembly 4 in the second position, the pressurization process is the syringe self Figure 1 Status Movement to Figure 2 state;

[0069] (2) Then the button sleeve 5 is rotated in a second direction opposite to the first direction, and the center ring sleeve 402 moves from the second position to the first position (i.e., moves backward), and drives the fixed sleeve 404 to move backward synchronously through the transition sleeve 403. The fixed sleeve 404 drives the piston assembly 2 to move backward through the steel ball 601, and the piston assembly 2 gradually draws the medicine liquid. At the same time, the pushing sleeve 603 drives the unlocking sleeve 602 to move backward through the second elastic member 8 so that the inner peripheral wall of the unlocking sleeve 602 is always pressed against the notch of the floating groove 401 to confine the steel ball 601 in the floating groove 401 and the locking groove 201. This is the medicine absorption process; Figure 4 is a state diagram of the sliding sleeve assembly 4 in the second position, Figure 6The state diagram of the sliding sleeve assembly 4 returning from the second position to the first position, the drug aspiration process is the syringe self Figure 4 Status Movement to Figure 6 Status, such as Figure 5 As shown, the threaded connection portion between the center ring sleeve 402 and the inner sleeve 3 is located at the front end, as shown in FIG. Figure 7 As shown, the threaded connection portion between the center ring sleeve 402 and the inner sleeve 3 is located at the rear end, from which it can be seen that the sliding sleeve assembly 4 returns from the second position to the first position.

[0070] (3) After the liquid medicine is sucked to a predetermined dose, the button sleeve 5 is held to press the syringe against the injection site, and the safety knob 901 is turned, which drives the safety ring 902 to rotate synchronously until the safety cavity 9021 is aligned with the limiting sleeve 903. The button sleeve 5 is pressed, and the button sleeve 5 drives the limiting sleeve 903 to pass through the safety cavity 9021, so that the limiting sleeve 903 and the unlocking sleeve 602 overcome the pressure of the second elastic member 8 and move toward the direction of the piston assembly 2 and apply pressure to the piston assembly 2 through the pushing sleeve 603, and the piston assembly 2 is engaged with the locking sleeve 603. The steel ball 601 inserted into the locking groove 201 exerts pressure. When the unlocking groove 6021 on the unlocking sleeve 602 is aligned with the floating groove 401, the steel ball 601 enters the unlocking groove 6021 under the pressure of the piston assembly 2. At the same time, the outer peripheral wall of the pushing sleeve 603 presses against the steel ball 601 to confine it in the floating groove 401 and the unlocking groove 6021. At this time, the piston assembly 2 and the sliding sleeve assembly 4 are unlocked, the first elastic member 7 is reset, and the piston assembly 2 pushes the liquid medicine out of the spray hole under the elastic force of the first elastic member 7. This is the injection process; Figure 6 The state diagram of the sleeve assembly 4 returning to the first position after being pressurized, Figure 2 This is the state diagram after the piston assembly pushes out the liquid medicine. The injection process is the process of the syringe automatically Figure 6 Status Movement to Figure 1 state.

[0071] (4) After the injection is completed, multiple injections can be achieved by following a cycle of pressurization, drug inhalation, and injection.

[0072] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A needle-free syringe, characterized in that: include: The injection mechanism comprises a piston cylinder (1) and a piston assembly (2) slidably arranged in the piston cylinder (1) to push out the liquid medicine in the piston cylinder (1) to implement the injection; and a firing assembly, comprising an inner sleeve (3), a sleeve assembly (4) threadedly connected to the inner sleeve (3), a button sleeve (5) sleeved outside the sleeve assembly (4) and circumferentially fixed thereto, a clamping mechanism (6), a first elastic member (7) arranged between the sleeve assembly (4) and the piston assembly (2), and a second elastic member (8) arranged between the piston assembly (2) and the clamping mechanism (6); The sleeve assembly (4) has a first position and a second position along its axial direction. The clamping mechanism (6) is used to lock the piston assembly (2) on the sleeve assembly (4) after the sleeve assembly (4) overcomes the elastic force of the first elastic member (7) and moves from the first position to the second position. During the movement of the sleeve assembly (4) from the second position to the first position, the clamping mechanism (6) drives the piston assembly (2) to move away from the piston cylinder (1) to suck the liquid medicine. When the button sleeve (5) is pressed, the clamping mechanism (6) pushes the piston assembly (2) away from the sleeve assembly (4), so that the piston assembly (2) is injected under the elastic force of the first elastic member (7).

2. A needle-free injector according to claim 1, characterized in that: The clamping mechanism (6) comprises at least two steel balls (601) which are embedded in the sliding sleeve assembly (4) along the circumferential direction and are arranged in a floating manner, a locking groove (201) located on the piston assembly (2) for the steel balls (601) to be embedded in order to lock the piston assembly (2), and an unlocking sleeve (602) provided with an unlocking groove (6021) for the steel balls (601) to be embedded in order to unlock the piston assembly (2), and the sliding sleeve assembly (4) is provided with a floating groove (401) for the steel balls (601) to be embedded in. When the sliding sleeve assembly (4) moves from the first position to the second position, the steel ball (601) gradually slides out of the unlocking groove (6021) and enters the locking groove (201) of the piston assembly (2) under the push of the inner peripheral wall of the unlocking sleeve (602) to lock the piston assembly (2); When the button sleeve (5) drives the unlocking sleeve (602) to move in the direction of the piston assembly (2) until the unlocking groove (6021) is directly opposite to the floating groove (401), the unlocking sleeve (602) overcomes the elastic force of the second elastic member (8) to push the piston assembly (2) so that the steel ball (601) in the locking groove (201) is separated from the locking groove (201) and enters the unlocking groove (6021) to release the lock of the piston assembly (2).

3. The needle-free injector according to claim 1, characterized in that: It also includes a safety mechanism (9) which is used to prevent the clamping mechanism (6) from releasing the lock on the piston assembly (2) during the process of the piston assembly (2) sucking the medical liquid.

4. A needle-free injector according to claim 3, characterized in that: The safety mechanism (9) comprises a safety knob (901), a safety ring (902) circumferentially fixed to the safety knob (901) and provided with a safety cavity (9021) therein, a limiting sleeve (903) sleeved on the outside of the unlocking sleeve (602) and matching the shape of the safety cavity (9021), and a third elastic member (904) arranged between the safety knob (901) and the button sleeve (5) to drive the safety knob (901) to reset. When the safety knob (901) drives the safety ring (902) to rotate until the safety cavity (9021) is directly opposite to the limiting sleeve (903), the safety cavity (9021) allows the limiting sleeve (903) to pass through to unlock the piston assembly (2).

5. The needle-free injector according to claim 2, characterized in that: The sliding sleeve assembly (4) comprises a center ring sleeve (402) threadedly connected to the inner sleeve (3), a transition sleeve (403) axially fixed to the center ring sleeve (402), and a fixed sleeve (404) fixed to the transition sleeve (403) and provided with the above-mentioned floating groove (401), and the unlocking sleeve (602) is located between the fixed sleeve (404) and the transition sleeve (403).

6. A needle-free injector according to claim 5, characterized in that: A pushing sleeve (603) is slidably provided at one end of the fixing sleeve (404) away from the piston assembly (2), and the second elastic member (8) is located between the unlocking sleeve (602) and the pushing sleeve (603).

7. The needle-free injector according to claim 5, characterized in that: The center ring sleeve (402) includes an inner ring (4021) and an outer ring (4022), the inner sleeve (3) is arranged between the inner ring (4021) and the outer ring (4022) and is threadedly connected to the inner ring (4021), and the end of the outer ring (4022) close to the piston cylinder (1) is connected to a lens sleeve (405), a lens (406) is installed in the lens sleeve (405), and a pressure block (407) is pressed on the outside of the lens (406) to confine the lens (406) in the lens sleeve (405).

8. The needle-free injector according to claim 5, characterized in that: A fourth elastic member (10) is provided between the unlocking sleeve (602) and the transition sleeve (403).

9. The needle-free injector according to claim 4, characterized in that: An end of the button sleeve (5) facing away from the piston cylinder (1) is bent to form an end cover (501), and a positioning groove (5011) is protruded on the inner wall of the end cover (501) for the limiting sleeve (903) to be inserted to limit its circumference.

10. The needle-free injector according to claim 1, characterized in that: A limiting mechanism for axially limiting the button sleeve (5) and the sliding sleeve assembly (4) is provided between the button sleeve (5) and the sliding sleeve assembly (4), and the limiting mechanism comprises a limiting groove and a limiting protrusion (4023) respectively located on the button sleeve (5) and the sliding sleeve assembly (4).

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