Active self-locking syringe

Abstract

The present invention relates to the field of safety syringes, and specifically discloses an active self-locking syringe, including a syringe, a needle seat, a piston assembly, a piston rod protective cover, a needle tip protective cap, an injection needle, a needle tip protective sleeve, a spring, a guide limit assembly, an initial clamping assembly and a trigger ring plug. In the initial state, the trigger ring plug is located in a trigger cavity, and in the initial state, the trigger ring plug does not contact with the trigger part or contacts but not enough to allow the initial clamping assembly to separate from each other. The inner wall of the trigger ring plug is sealed with the needle seat, and the outer wall of the trigger ring plug is sealed with the inner wall of the syringe. In the above structure, the trigger ring plug is arranged in the trigger cavity, and the needle tip protective sleeve is released from the inside of the syringe near the patient end, so as to achieve the technical purpose of preventing the needle tip from being exposed and self-locking. The triggering method is cleverly designed, and there are no other auxiliary triggering components except the syringe and the needle tip protective sleeve. It has the technical advantages of simple structure, small radial size of the syringe, streamlined components and low production cost.

Description

Technical Field

[0001] The invention relates to the field of safety syringes, and in particular to an active self-locking syringe. Background Art

[0002] There are many types of safety syringes on the market, and there are generally two technical routes. One of them is the needle retractable safety syringe, that is, after the injection is completed, the needle tip can be automatically or manually retracted into the syringe or the needle tip protective sleeve, thereby avoiding the risk of the needle tip stabbing the user after use. The other technical route is the trigger-type safety syringe, that is, the needle tip is fixed relative to the syringe, and a triggerable needle tip protection device is usually set on the outside of the syringe. During the injection process, the syringe moves axially relative to the needle tip protection device. When the injection is completed, the syringe or piston rod triggers the needle tip protection device. After the needle tip protection device is triggered, it is sufficient to cover the injection needle to prevent the needle tip from being exposed.

[0003] The safety syringes based on the above two technical routes have complex structures and high production costs. Therefore, it is necessary to develop a new safety syringe to solve the defects of the existing technology. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an active self-locking syringe with an improved structure, which is triggered by the inside of the syringe to achieve the technical effects of simple structure, low cost and higher reliability.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: an active self-locking syringe, comprising at least:

[0006] A syringe, wherein a piston assembly is disposed in the syringe;

[0007] A needle seat, the needle seat is fixed in a position close to the patient end of the syringe, and a spring cavity close to the patient end and a trigger cavity close to the piston assembly are formed between the outer wall of the needle seat and the inner wall of the syringe;

[0008] An injection needle, the injection needle being fixed on the needle holder and the needle tip extending from the patient end of the syringe;

[0009] A needle tip protective cover, which is used to cover the used injection needle;

[0010] A spring, wherein the spring is located in the spring cavity, and an end of the spring close to the needle tip is in contact with the needle tip protective sleeve;

[0011] A guide limiter assembly, which is used to limit the direction and limit position of the axial movement of the needle tip shield relative to the syringe after being triggered;

[0012] An initial engagement assembly, which is used to keep the needle tip shield in a non-triggered state and is provided with a triggering portion that is triggered from the trigger cavity to disengage the initial engagement assemblies from each other;

[0013] A trigger ring plug is located in the trigger cavity and in an initial state the trigger ring plug does not contact the trigger portion or contacts but not enough to allow the initial engaging components to disengage from each other, the inner wall of the trigger ring plug is sealed from the needle seat, and the outer wall of the trigger ring plug is sealed from the inner wall of the syringe.

[0014] A preferred embodiment further comprises a non-return component, wherein the non-return component is used to prevent the needle tip shield from retracting in the protection state.

[0015] In a preferred embodiment, the non-return component comprises a non-return arm provided at the patient end of the syringe, the non-return arm is elastic, and the free end of the non-return arm protrudes from the outer wall of the syringe in the radial direction.

[0016] In a preferred embodiment, a slot penetrating the side wall of the needle tip protection sleeve close to the patient end is provided, and the slot is used to accommodate the extension of the anti-return arm.

[0017] In a preferred embodiment, the piston assembly includes a piston rod and a piston disposed at an end of the piston rod, and the end of the piston rod is a pushing portion for pushing the trigger ring plug.

[0018] In a preferred embodiment, a matching engaging mechanism is provided between the end of the needle seat away from the patient end and the end of the piston rod close to the needle seat.

[0019] In a preferred embodiment, the guide and limit assembly comprises a boss provided on the outer wall of the syringe and a guide and limit groove provided on the side wall of the needle tip protection sleeve, and the boss is adapted to fit the guide and limit groove.

[0020] In a preferred embodiment, the initial engaging assembly includes an elastic arm arranged on the needle tip protection sleeve and an engaging groove penetrating the outer wall of the syringe, the free end of the elastic arm is provided with a engaging block extending radially toward the inside of the needle tip protection sleeve, and the engaging block is engaged with the engaging end of the engaging groove close to the patient end.

[0021] In a preferred embodiment, the trigger portion comprises a trigger arm connected to a side of the engaging groove away from the engaging end, the trigger arm is elastic, and in an initial state, the free end of the trigger arm is located on the inner side of the engaging block in the radial direction.

[0022] In a preferred embodiment, the free end of the elastic arm and the free end of the non-return arm are in conflict with each other in the needle tip protection state.

[0023] In a preferred embodiment, the free end of the elastic arm is lower than the end surface of the needle tip protection sleeve in the axial direction.

[0024] A preferred embodiment further comprises a needle tip protective cap sleeved outside the needle tip protective sleeve, wherein the needle tip protective cap covers the free end of the elastic wall in an initial state.

[0025] A preferred embodiment further comprises a piston rod protection cover connected to the end of the syringe away from the patient end.

[0026] The active self-locking syringe of this embodiment is triggered by a trigger ring plug arranged in the trigger chamber, and the needle tip protection sleeve is released from the inside of the syringe close to the patient end, so as to achieve the technical purpose of preventing the needle tip from being exposed and self-locking. The triggering method is cleverly designed, and there are no other auxiliary triggering components besides the syringe and the needle tip protection sleeve. It has the technical advantages of simple structure, small radial size of the syringe, streamlined components and low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The figure shows the external structure of the active self-locking syringe of this embodiment;

[0028] Figure 2 The figure shows the structure schematic diagram of the explosion state of the active self-locking syringe of this embodiment;

[0029] Figure 3 The figure shows a partial cross-sectional view of the active self-locking syringe of the present embodiment in the initial state (not triggered);

[0030] Figure 4 The figure shows a partial cross-sectional view of the syringe in the active self-locking syringe of the present embodiment;

[0031] Figure 5 The figure shows a partial cross-sectional view of the active self-locking syringe of this embodiment in the needle tip protection state;

[0032] Figure 6 Shown is a schematic structural diagram of the active self-locking syringe of this embodiment when not in use. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] like Figure 1 , Figure 2 As shown, an active self-locking syringe of this embodiment includes a syringe 10, a piston assembly, an injection needle 60, a needle tip protection sleeve 30, a spring 70 and a needle tip protection cap 40. In this embodiment, in order to facilitate the description of the structure, one end of the injection needle of the active self-locking syringe is defined as the patient end.

[0035] In this embodiment, the piston assembly is assembled in the syringe, and its structure is as follows: Figure 2 , Figure 3 As shown, it includes a piston rod 20 and a piston 23, wherein the end of the piston rod 20 close to the patient end is provided with a piston ring groove 22, and the piston ring groove 22 is sleeved with a piston 23, wherein the piston 23 and the piston rod 20 are pistons and piston rods commonly used in the prior art, the piston 23 is made of flexible material, and is sealed with the inner wall of the syringe 10, and the inhalation and injection of the liquid medicine are achieved by pushing and pulling the piston assembly.

[0036] As an improvement of this embodiment, a pushing portion 21 is provided at the end of the piston rod 20 , and the function of the pushing portion 21 is to push the trigger ring plug 50 to move axially, wherein the end face of the pushing portion 21 is adapted to the end face of the trigger ring plug 50 .

[0037] As an improvement of this embodiment, Figure 4 As shown, the needle seat 16 is fixed in the syringe 10 at a position close to the patient end, and the injection needle 60 is fixed on the needle seat 16 and the needle tip extends from the patient end of the syringe 10. The outer wall of the needle seat 16 is fixedly connected to the inner wall of the syringe, and forms a spring chamber 17 close to the patient end and a trigger chamber 18 close to the piston assembly.

[0038] A preferred embodiment, as Figure 3 , Figure 5 As shown, a matching interlocking mechanism is provided between the end of the needle seat 16 away from the patient end and the end of the piston rod 20 close to the needle seat, which is used to reduce the residual amount of the liquid medicine during the injection process. Preferably, the interlocking mechanism includes an outer cone 19 provided at the end of the needle seat and a tapered groove 24 located at the end of the piston rod. Of course, the tapered groove can also be provided at the end of the needle seat, and the outer cone is provided at the end of the piston rod. The outer cone and the tapered groove can also be an outer arc surface and an arc groove. All equivalent technical means in the art with the same technical concept as the interlocking mechanism in this embodiment are regarded as equivalent technical solutions of this application.

[0039] like Figure 3 As shown, a trigger ring plug 50 is installed in the trigger chamber 18, and the inner wall of the trigger ring plug 50 is sealed with the outer wall of the needle seat 16, and the outer wall of the trigger ring plug 50 is sealed with the inner wall of the syringe. In this embodiment, the trigger ring plug 50 can move axially in the trigger chamber, and the movement of the trigger ring plug 50 is achieved by the pushing of the pushing portion 21.

[0040] In this embodiment, if Figure 3As shown, the needle tip shield 30 is used to cover the used injection needle 60. The needle tip shield 30 is initially sleeved on the patient end of the syringe. A spring 70 is provided between the needle tip shield 30 and the syringe. The spring 70 is located in the spring cavity 17. The end of the spring close to the needle tip contacts the needle tip shield. In the initial state, the spring 70 is in a compressed energy storage state, providing a pre-elastic force for the ejection of the needle tip shield.

[0041] In this embodiment, an initial engagement assembly is provided between the needle tip shield 30 and the syringe 10 to keep the needle tip shield 30 in a non-triggered state. Figure 2 , Figure 3 As shown, a preferred initial engagement assembly of this embodiment includes an elastic arm 32 arranged on the needle tip protection sleeve and an engagement groove 12 penetrating the outer wall of the syringe, wherein the free end of the elastic arm 32 is provided with a engagement block 33 extending radially toward the inside of the needle tip protection sleeve, and the engagement block is engaged with the engagement end 13 of the engagement groove close to the patient end.

[0042] It should be noted that the engaging groove 12 is located on the outer wall of the syringe where the trigger cavity 18 is located, and the initial engaging assembly also includes a triggering part that is triggered from the trigger cavity 18 to separate the initial engaging assemblies from each other. Preferably, the triggering part includes a triggering arm 14 connected to the side of the engaging groove away from the engaging end, and the triggering arm 14 is elastic. Figure 3 As shown, the free end of the trigger arm 14 is located on the inner side of the clamping block in the radial direction.

[0043] A preferred embodiment, as Figure 1 , Figure 2 As shown, a guide limit assembly is provided between the needle tip shield 30 and the syringe 10, and the guide limit assembly is used to limit the direction and limit position of the axial movement of the needle tip shield 30 relative to the syringe after being triggered. Preferably, the guide limit assembly in this embodiment includes a boss 11 provided on the outer wall of the syringe and a guide limit groove 31 provided on the side wall of the needle tip shield, wherein the boss is adapted to the guide limit groove, and is used to limit the relative rotation between the needle tip shield 30 and the syringe 10, and can only move in the axial direction, and the end of the guide limit groove 31 limits the limit position of the axial movement of the needle tip shield 30.

[0044] In the initial state, the trigger ring plug 50 of the active self-locking syringe of this embodiment is located in the trigger cavity 18 and in the initial state, the trigger ring plug does not contact the trigger part or contacts but not enough to allow the initial engaging components to disengage from each other. During use, the piston assembly first moves toward the end away from the needle tip to draw the liquid medicine into the syringe. During the injection process, the piston assembly moves toward the end of the needle tip. During the advancement of the piston assembly, the push portion 21 first contacts the trigger ring plug 50, and continues to push the trigger ring plug 50 to move axially after contact. The trigger ring plug 50 drives the trigger arm 14 to gradually expand outward, and the trigger arm 14 drives the clamping block 33 to gradually deform radially outward, so that the clamping block 33 is disengaged from the clamping end 13. The clamping block 33 and the clamping end 13 are completely separated when the injection of the drug solution is completed. At this time, since the injection needle has not been pulled out from the patient's skin, the patient end of the needle tip protection sleeve 30 is in contact with the patient's skin. In the process of pulling the injection needle out of the patient's skin, the potential energy stored in the spring 70 is released, driving the needle tip protection sleeve 30 to cover the used injection needle, preventing the injection needle from being exposed and injuring people and achieving self-locking.

[0045] As an improvement of this embodiment, it also includes a non-return component for preventing the needle tip protective cover from retracting in the protective state. Figure 2-5 As shown, the non-return component of this embodiment comprises a non-return arm 15 arranged at the patient end of the syringe. The non-return arm 15 is elastic, and the free end of the non-return arm 15 protrudes from the outer wall of the syringe in the radial direction.

[0046] like Figure 5 As shown, in the needle tip protection state, the free end of the elastic arm 32 and the free end of the check arm 15 contact each other to achieve self-locking. Since the check arm 15 protrudes from the outer wall of the syringe in the radial direction, the outer diameter of the free end of the check arm 15 is greater than the outer diameter of the free end of the elastic arm 32, thereby preventing the needle tip protection sleeve from retracting, and the check component makes the protection reliability better.

[0047] A preferred embodiment, as Figure 1-3 As shown, a slot hole 34 penetrating the side wall of the needle tip protection sleeve 30 close to the patient end is provided, and the slot hole 34 is used to accommodate the extension of the anti-return arm in the initial state.

[0048] A preferred embodiment, as Figure 2 As shown, a through groove 36 is provided on the outer wall of the needle tip shield, and the elastic arm 32 is located in the through groove 36. The free end of the elastic arm 32 can be higher or lower than the end surface of the needle tip shield 30 in the axial direction, or can be flush with the end surface of the needle tip shield 30. Preferably, the free end of the elastic arm 32 is lower than the end surface of the needle tip shield 30 in the axial direction. The purpose of such a setting is to reduce the stroke of the needle tip shield and ensure that the ejection force of the spring ejects the needle tip shield into place.

[0049] A preferred embodiment, as Figure 1 , Figure 6 As shown, the active self-locking syringe of this embodiment is also provided with a piston rod protective cover 80, which is sleeved on the end of the syringe away from the patient end in the initial unused state to prevent the piston rod from being pushed and avoid accidental triggering of the needle tip protective cover.

[0050] A preferred embodiment, as Figure 1 , Figure 6 As shown, in this embodiment, the needle tip cap 40 is sleeved on the needle tip protective sleeve 30. Preferably, the needle tip protective sleeve is also provided with a step surface 35 engaged with the end of the needle tip cap. It should be noted that when the needle tip cap is installed on the needle tip protective sleeve, it covers the free end of the elastic arm 32. The purpose of such a setting is that even if the piston rod is pushed, since the elastic arm 32 is pressed and has no deformation space, the trigger ring plug cannot enter the trigger space inside the trigger arm, which can also avoid the needle tip protective sleeve from being triggered by mistake.

[0051] It should be noted that in this embodiment, the number of the guide limiter components, the initial engaging components and the non-return components are all two groups, which are evenly distributed along the circumferential direction. Of course, this is only the best embodiment, in which the number of the guide limiter components, the initial engaging components and the non-return components can also be one group or more than three groups, and in the case of more than three groups, they are distributed along the circumferential direction, preferably evenly distributed along the circumferential direction.

[0052] In short, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An active self-locking syringe, characterized in that: At least: A syringe (10), wherein a piston assembly is provided in the syringe; A needle seat (16), the needle seat being fixed in a position close to the patient end in the syringe, and a spring chamber (17) close to the patient end and a trigger chamber (18) close to the piston assembly are formed between the outer wall of the needle seat and the inner wall of the syringe; An injection needle (60), the injection needle being fixed on the needle holder and the needle tip extending from the patient end of the syringe; A needle tip protective cover (30), the needle tip protective cover is used to cover a used injection needle; A spring (70), the spring being located in the spring cavity, and an end of the spring close to the needle tip being in contact with the needle tip protective sleeve; A guide limiter assembly, which is used to limit the direction and limit position of the axial movement of the needle tip shield relative to the syringe after being triggered; An initial engagement assembly, which is used to keep the needle tip shield in a non-triggered state and is provided with a triggering portion that is triggered from the trigger cavity to disengage the initial engagement assemblies from each other; A trigger ring plug (50), the trigger ring plug is located in the trigger cavity and in an initial state the trigger ring plug does not contact the trigger portion or contacts but not enough to allow the initial engaging components to disengage from each other, the inner wall of the trigger ring plug is sealed against the needle seat, and the outer wall of the trigger ring plug is sealed against the inner wall of the syringe.

2. The active self-locking syringe according to claim 1, characterized in that: The invention also comprises a non-return component, wherein the non-return component is used to prevent the needle tip protection sleeve from retracting in the protection state.

3. The active self-locking syringe according to claim 2, characterized in that: The non-return component comprises a non-return arm (15) arranged at the patient end of the syringe, the non-return arm is elastic, and the free end of the non-return arm protrudes from the outer wall of the syringe in the radial direction.

4. The active self-locking syringe according to claim 3, characterized in that: A slot hole (34) penetrating the side wall of the needle tip protective sleeve close to the patient end is provided, and the slot hole is used to accommodate the extension of the anti-return arm.

5. The active self-locking syringe according to any one of claims 1 to 4, characterized in that: The piston assembly comprises a piston rod (20) and a piston (23) arranged at the end of the piston rod, and the end of the piston rod is a pushing portion (21) used for pushing a trigger ring plug.

6. The active self-locking syringe according to claim 5, characterized in that: A matching fitting mechanism is provided between an end of the needle seat (16) away from the patient and an end of the piston rod (20) close to the needle seat.

7. An active self-locking syringe according to any one of claims 1 to 4 or 6, characterized in that: The guide limiter assembly comprises a boss (11) provided on the outer wall of the syringe and a guide limiter groove (31) provided on the side wall of the needle tip protective sleeve, wherein the boss is adapted to fit the guide limiter groove.

8. The active self-locking syringe according to any one of claims 2 to 4 or 6, characterized in that: The initial engagement assembly comprises an elastic arm (32) provided on the needle tip protective sleeve and an engagement groove (12) penetrating the outer wall of the syringe, wherein the free end of the elastic arm is provided with an engagement block (33) extending radially toward the inside of the needle tip protective sleeve, and the engagement block is engaged with the engagement end (13) of the engagement groove close to the patient end.

9. The active self-locking syringe according to claim 8, characterized in that: The trigger part comprises a trigger arm (14) connected to a side of the engaging groove away from the engaging end, the trigger arm being elastic, and in an initial state, a free end of the trigger arm being located on the inner side of the engaging block in a radial direction.

10. The active self-locking syringe according to claim 8, characterized in that: The free end of the elastic arm and the free end of the non-return arm are in conflict with each other in the needle tip protection state.

11. The active self-locking syringe according to claim 9 or 10, characterized in that: It also includes a needle tip protective cap (40) sleeved on the outside of the needle tip protective sleeve, wherein the needle tip protective cap covers the free end of the elastic arm (32) in an initial state.

12. The active self-locking syringe according to any one of claims 1 to 4 or 6 or 9 to 10, characterized in that: Also included is a piston rod cover (80) connected to the end of the syringe remote from the patient end.

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