Needle core and needle tube assembly of biopsy needle

Abstract

The utility model discloses a needle core and needle tube assembly of a biopsy needle, which relates to the technical field of biopsy needles and comprises an outer shell, a mounting shell, a first mounting block, a second mounting block, a first excitation button and a second excitation button. The mounting shell is arranged in the outer shell, and a containing cavity is formed in the mounting shell; the first mounting block is arranged in the accommodating cavity in a sliding manner, and the first mounting block is connected with a needle tube extending out of the outer shell; the second mounting block is arranged in the containing cavity in a sliding mode, the second mounting block is connected with a needle core extending out of the outer shell, the needle core penetrates through the needle tube, and the movement direction of the first mounting block is parallel to the movement direction of the second mounting block; the first excitation button is arranged between the outer shell and the mounting shell in a sliding manner, and the first excitation button is in buckled connection with the first mounting block; the second excitation button is arranged between the outer shell and the installation shell in a sliding mode, and the second excitation button is connected with the second installation block in a buckled mode. According to the utility model, the production efficiency can be improved.

Description

Technical Field

[0001] This utility model relates to the field of biopsy needle technology, and in particular to a biopsy needle core tube assembly. Background Technology

[0002] Biopsy, short for "vital tissue examination," is a pathological examination technique that requires the use of specialized equipment to obtain a portion of the lesion tissue (often the entire lesion is taken if it is small and located on the body surface) for pathological biopsy. This provides a definitive basis for developing a treatment plan, allowing for elective surgery or other treatment measures. The advantages of biopsy include: minimal trauma, reduced patient pain, shorter recovery time, and lower operational difficulty. Current technology uses a protrusion and hole-like connection between the activation button and the mounting block for transmission rather than a fixed connection. When assembling the activation button, the operator must manually assemble the activation button and inner shell into the outer shell. This is difficult to operate and results in low production efficiency. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a biopsy needle core assembly that can improve production efficiency.

[0004] A biopsy needle core assembly according to a first aspect of the present invention includes: an outer housing, a mounting housing, a first mounting block, a second mounting block, a first activation button, and a second activation button. The mounting housing is disposed within the outer housing, and a receiving cavity is provided within the mounting housing. The first mounting block is slidably disposed within the receiving cavity, and a needle tube extending out of the outer housing is connected to the first mounting block. The second mounting block is slidably disposed within the receiving cavity, and a needle core extending out of the outer housing is connected to the second mounting block. The needle core passes through the needle tube, and the movement direction of the first mounting block is parallel to the movement direction of the second mounting block. The first activation button is slidably disposed between the outer housing and the mounting housing, and is snap-fitted to the first mounting block. The second activation button is slidably disposed between the outer housing and the mounting housing, and is snap-fitted to the second mounting block.

[0005] According to an embodiment of the present invention, a biopsy needle core tube assembly has at least the following beneficial effects: by using a snap-fit ​​connection, the first activation button and the first mounting block can be easily pre-assembled, and the second activation button and the second mounting block can be pre-assembled before being placed into the mounting housing. In this way, when the mounting housing is snapped onto the outer housing, compared with the prior art where the first activation button and the first mounting block are not fixedly connected, the first activation button and the second activation button are not easily separated from the mounting housing, which effectively improves the installation speed and increases production efficiency.

[0006] According to some embodiments of the present invention, the first mounting block includes a first connecting part and a first sliding limiting part. Sliding holes are provided on both sides of the mounting housing. The first sliding limiting part extends into the sliding hole and can slide along the sliding hole. The first connecting part is connected to the first sliding limiting part and is used to fix the needle tube.

[0007] According to some embodiments of the present invention, the sidewall of the sliding hole is provided with an auxiliary sliding groove, and the first sliding limiting part is connected to an auxiliary slider embedded in the auxiliary sliding groove.

[0008] According to some embodiments of the present invention, a first adhesive groove is provided in the first connecting part, the needle passes through the first adhesive groove in the first connecting part, and an adhesive for fixing the needle is provided in the first adhesive groove.

[0009] According to some embodiments of the present invention, the first adhesive groove sidewall is provided with a first adhesive block.

[0010] According to some embodiments of the present invention, the first mounting block includes a first snap-fit ​​portion, which is connected to the first sliding limiting portion. A first slot for fixing the first snap-fit ​​portion is formed inside the mounting housing. A first elastic member is sleeved on the outside of the first snap-fit ​​portion. The first elastic member is used to push the needle tube to move in the direction of extending out of the outer housing. The first trigger button is used to drive the needle tube to move in the direction of retracting into the outer housing.

[0011] According to some embodiments of the present invention, a plurality of first abutting portions are arranged around the side of the first connecting portion, and the outer peripheral wall of the first abutting portion abuts against the first elastic member.

[0012] According to some embodiments of the present invention, the second mounting block includes a second connecting part and a second sliding limiting part. The second sliding limiting part extends into the sliding hole and can slide along the sliding hole. The second connecting part is connected to the second sliding limiting part and is used to fix the needle core.

[0013] According to some embodiments of the present invention, a second adhesive groove is provided in the second connecting part, the needle core passes through the second adhesive groove in the second connecting part, and an adhesive for fixing the needle core is provided in the second adhesive groove.

[0014] According to some embodiments of the present invention, the second mounting block includes a second latching part, which is connected to the second sliding limiting part. A second slot is formed inside the mounting housing for fixing the second latching part. A second elastic member is sleeved on the outside of the second latching part. The second elastic member is used to push the needle core to move in the direction of extending out of the outer housing. The second trigger button is used to drive the needle core to move in the direction of retracting into the outer housing.

[0015] A biopsy needle core assembly according to an embodiment of the present invention has at least the following beneficial effects:

[0016] (1) The snap-fit ​​connection method makes it difficult for the first and second trigger buttons to be separated from the mounting housing, which effectively improves the installation speed and production efficiency;

[0017] (2) The needle tube and needle core are fixed by filling the first and second glue tanks with adhesive. The structure is simple and the fixation is reliable.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0020] Figure 1 This is a schematic diagram of an embodiment of the present utility model;

[0021] Figure 2 This is an exploded view of one embodiment of the present invention;

[0022] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0023] Figure 4 This is a schematic diagram of the first mounting block according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the second mounting block according to an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the mounting housing according to one embodiment of the present invention;

[0026] Figure 7 This is an exploded view of the mounting housing according to one embodiment of the present invention;

[0027] Figure 8 This is a schematic diagram of the first trigger button according to an embodiment of the present invention;

[0028] Figure 9 This is a schematic diagram of the second trigger button according to an embodiment of the present invention.

[0029] Icon labels:

[0030] Outer casing 100;

[0031] Mounting housing 200, upper housing 201, lower housing 202, receiving cavity 210, sliding hole 220, auxiliary slide groove 221, first bayonet 230, second bayonet 240;

[0032] First mounting block 300, first connecting part 310, first glue groove 311, first adhesive block 312, first abutting part 313, first sliding limiting part 320, auxiliary slider 321, first triggering buckle 322, first buckling part 330, first elastic element 331;

[0033] Syringe 400;

[0034] Second mounting block 500, second connecting part 510, second glue groove 511, second sliding limit part 520, second triggering buckle 521, second buckle part 530, second elastic member 531;

[0035] Needle core 600;

[0036] First activation button 700, first activation slot 710;

[0037] Second trigger button 800, second trigger slot 810. Detailed Implementation

[0038] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0039] In the description of this utility model, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0040] In the description of this utility model, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features or their sequential relationship.

[0041] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0042] Reference Figures 1 to 9As shown, an embodiment of the present invention provides a biopsy needle core assembly, comprising: an outer housing 100, a mounting housing 200, a first mounting block 300, a second mounting block 500, a first activation button 700, and a second activation button 800. Both the mounting housing 200 and the outer housing 100 are injection molded from plastic. The mounting housing 200 is divided into an upper housing 201 and a lower housing 202. The upper housing 201 has multiple insertion holes, and the lower housing 202 has multiple insertion posts. The insertion posts are embedded in corresponding insertion holes, with an interference fit between the insertion posts and the insertion holes. The mounting housing 200 is connected to the outer housing 100 by snap-fit ​​or bolts. The mounting housing 200 has a receiving cavity 210. The receiving cavity 210 is divided into a first cavity and a second cavity by a middle partition. The first mounting block 300 is slidably disposed in the receiving cavity 210. Specifically, the first mounting block 300 is slidably disposed in the first cavity and can move along the extension direction of the first cavity. The first mounting block 300 is connected to a needle tube 400 extending out of the outer housing 100; the needle tube 400 is a hollow metal tube, and its extension direction is the same as that of the first cavity. When the first mounting block 300 moves along the first cavity, it can drive the needle tube 400 to move along its extension direction. The second mounting block 500 is slidably disposed in the receiving cavity 210; specifically, the second mounting block 500 is slidably disposed in the second cavity, and it can move along the extension direction of the second cavity. The second mounting block 500 is connected to a needle core 600 extending out of the outer housing 100. The needle core 600 passes through the needle tube 400. The movement direction of the first mounting block 300 is parallel to the movement direction of the second mounting block 500, so that when the second mounting block 500 moves the needle core 600, the needle core 600 can move along the extension direction of the needle tube 400. The first activation button 700 is slidably disposed between the outer housing 100 and the mounting housing 200, and is snap-fitted to the first mounting block 300. The second activation button 800 is slidably disposed between the outer housing 100 and the mounting housing 200, and is snap-fitted to the second mounting block 500. The function of the first activation button 700 and the second activation button 800 is to drive the first mounting block 300 and the second mounting block 500 to move, respectively. By using a snap-fit ​​connection method, compared to the existing technology where the first activation button 700 and the first mounting block 300 are not fixedly connected during installation, the first activation button 700 and the first mounting block 300 can be pre-assembled, and the second activation button 800 and the second mounting block 500 can be pre-assembled before being placed into the mounting housing 200. In this way, during the process of snapping the mounting housing 200 onto the outer housing 100, the first activation button 700 and the second activation button 800 are not easily separated from the mounting housing 200, effectively improving the installation speed.

[0043] Reference Figure 4As shown, the first mounting block 300 includes a first connecting portion 310 and a first sliding limiting portion 320, which are integrally formed. The first sliding limiting portion 320 is C-shaped, and the first connecting portion 310 is located at the center of the C-shaped first sliding limiting portion 320. Sliding holes 220 are provided on both sides of the mounting housing 200. The left and right sides of the first sliding limiting portion 320 extend into the corresponding sliding holes 220 and can slide along the sliding holes 220. The first connecting portion 310 is connected to the first sliding limiting portion 320 and is used to fix the needle tube 400. The needle tube 400 is made of metal, while the first sliding limiting portion 320 is typically made of low-friction plastics such as polytetrafluoroethylene, polyetheretherketone, or polyoxymethylene. The first connecting portion 310 is needed to fix the needle tube 400 and the first sliding limiting portion 320, which are made of different materials.

[0044] Reference Figure 4 and Figure 7 As shown, it can be understood that an auxiliary sliding groove 221 is provided on the side wall of the sliding hole 220, and the extending direction of the auxiliary sliding groove 221 is the same as the extending direction of the sliding hole 220. The first sliding limiting part 320 is connected to an auxiliary slider 321 embedded in the auxiliary sliding groove 221. The auxiliary slider 321 cooperates with the auxiliary sliding groove 221 to limit the first sliding limiting part 320 in the left and right directions, preventing the first sliding limiting part 320 from disengaging from the sliding hole 220. It can be foreseen that the sliding hole 220 is formed by the gap between the upper housing 201 and the lower housing 202 to facilitate the installation of the first mounting block 300 and the second mounting block 500.

[0045] Reference Figure 4 As shown, it can be understood that a first adhesive groove 311 is provided in the first connecting part 310, and the needle tube 400 passes through the first adhesive groove 311 in the first connecting part 310. The first adhesive groove 311 is provided with adhesive for fixing the needle tube 400. During assembly, the needle tube 400 is first passed through the first adhesive groove 311, and then the opening of the first adhesive groove 311 is kept facing upward. Adhesives such as epoxy resin, acrylic resin, and polyurethane are injected into the first adhesive groove 311. After the adhesive cures, the needle tube 400 is fixed in the first adhesive groove 311 under the action of the adhesive.

[0046] Reference Figure 4 As shown, it can be understood that the first adhesive tank 311 has a first adhesive-fixing block 312 on its side wall. The first adhesive-fixing block 312 increases the contact area between the adhesive and the first adhesive tank 311, which can effectively prevent the adhesive from separating from the side wall of the first adhesive tank 311 during use.

[0047] Reference Figure 2 and Figure 3As shown, the first mounting block 300 includes a first latching part 330, which is connected to a first sliding limiting part 320. The first latching part 330 and the first sliding limiting part 320 are integrally injection molded. A first latching slot 230 for fixing the first latching part 330 is formed inside the mounting housing 200. The first latching slot 230 is located on the middle partition. A first elastic element 331 is sleeved on the outside of the first latching part 330. The first elastic element 331 can be a metal spring or a non-metallic spring. The first elastic element 331 is used to push the needle tube 400 to move in the direction of extending out of the outer housing 100, and the first trigger button 700 is used to drive the needle tube 400 to move in the direction of retracting into the outer housing 100. The first trigger button 700 can push the first connecting part 310 to compress the first elastic member 331 and make the first latching part 330 insert into the first bayonet 230. When the first latching part 330 is disengaged from the first bayonet 230 under the action of external force, the first elastic member 331 pushes the first connecting part 310 to reset and makes the needle tube 400 move in the direction of extending out of the outer housing 100.

[0048] Reference Figure 4 and Figure 8 As shown, the first trigger button 700 has a first trigger slot 710 on its side, and the portion of the first sliding limit part 320 extending out of the sliding hole 220 is provided with a first trigger buckle 322, which can be engaged in the first trigger slot 710. During installation, the operator only needs to press the first trigger buckle 322 firmly into the first trigger slot 710 to connect the first trigger button 700 and the first mounting block 300.

[0049] Reference Figures 1 to 9 As shown, it can be understood that a plurality of first abutment portions 313 are arranged around the side of the first connecting portion 310. The outer peripheral walls of the plurality of first abutment portions 313 are arranged in a circumferential shape. The outer peripheral walls of the first abutment portions 313 abut against the first elastic member 331. The outer peripheral walls of the first abutment portions 313 axially limit the first elastic member 331 to prevent the first elastic member 331 from shaking during compression and reset, so that the first mounting block 300 moves more smoothly.

[0050] Reference Figures 1 to 9As shown, the second mounting block 500 includes a second connecting portion 510 and a second sliding limiting portion 520, which are integrally formed. The second sliding limiting portion 520 is C-shaped, and the second connecting portion 510 is located at the center of the C-shaped second sliding limiting portion 520. Sliding holes 220 are provided on both sides of the mounting housing 200, and the left and right sides of the second sliding limiting portion 520 extend into the corresponding sliding holes 220 and can slide along the sliding holes 220. The second connecting portion 510 is connected to the second sliding limiting portion 520 and is used to fix the needle core 600. The needle core 600 is made of metal, while the second sliding limiting portion 520 is typically made of low-friction plastics such as polytetrafluoroethylene, polyetheretherketone, or polyoxymethylene. The second connecting portion 510 is needed to fix needle cores 600 and second sliding limiting portions 520 made of different materials.

[0051] Reference Figures 1 to 9 As shown, it can be understood that a second adhesive groove 511 is provided in the second connecting part 510, and the needle core 600 passes through the second adhesive groove 511 in the second connecting part 510. The second adhesive groove 511 is provided with adhesive for fixing the needle core 600. During assembly, the needle core 600 is first passed through the second adhesive groove 511, and then the opening of the second adhesive groove 511 is kept facing upward. Adhesives such as epoxy resin, acrylic resin, and polyurethane are injected into the second adhesive groove 511. After the adhesive cures, the needle core 600 is fixed in the second adhesive groove 511 under the action of the adhesive.

[0052] Reference Figures 1 to 9 As shown, the second mounting block 500 includes a second latching part 530, which is connected to the second sliding limiting part 520. The second latching part 530 and the second sliding limiting part 520 are integrally injection molded. A second latch 240 for fixing the second latching part 530 is provided on the rear side of the mounting housing 200. The second latch 240 is located on the middle partition. A second elastic element 531 is sleeved on the outer side of the second latching part 530. The second elastic element 531 can be a metal spring or a non-metallic spring. The second elastic element 531 is used to push the needle core 600 to move in the direction of extending out of the outer housing 100, and the second trigger button 800 is used to drive the needle core 600 to move in the direction of retracting into the outer housing 100. The second trigger button 800 can push the second connecting part 510 to compress the second elastic member 531 and make the second latching part 530 insert into the second bayonet 240. When the second latching part 530 is disengaged from the second bayonet 240 under the action of external force, the second elastic member 531 pushes the second connecting part 510 to reset and makes the needle core 600 move in the direction of extending out of the outer housing 100.

[0053] It is foreseeable that the second trigger button 800 has a second trigger slot 810 on its side, and the portion of the second sliding limit part 520 extending out of the sliding hole 220 is provided with a second trigger buckle 521, which can be engaged in the second trigger slot 810. During installation, the operator only needs to press the second trigger buckle 521 firmly into the second trigger slot 810 to connect the second trigger button 800 and the second mounting block 500.

[0054] Understandably, the second connecting part 510 is provided with a plurality of second abutting parts around its side. The outer peripheral walls of the plurality of second abutting parts are arranged in a circular shape. The outer peripheral walls of the second abutting parts abut against the second elastic member 531. The outer peripheral walls of the second abutting parts axially limit the second elastic member 531 to prevent the second elastic member 531 from shaking during compression and reset, so that the second mounting block 500 moves more smoothly.

[0055] It is foreseeable that, in order to reduce the mold opening cost of manufacturing, the structure of the first mounting block 300 is the same as that of the second mounting block 500, so as to achieve the commonality of parts. During installation, the first sliding limit part 320 on the first mounting block 300 and the second sliding limit part 520 on the second mounting block 500 are respectively embedded in the sliding holes 220 on the left and right sides.

[0056] Installation steps: First, pass the needle 400 through the first adhesive groove 311, then, keeping the opening of the first adhesive groove 311 facing upwards, inject adhesives such as epoxy resin, acrylic resin, and polyurethane into the first adhesive groove 311. Wait for the adhesive to cure. After the adhesive cures, the needle 400 is fixed in the first adhesive groove 311 by the adhesive. Next, pass the needle core 600 through the second adhesive groove 511, then, keeping the opening of the second adhesive groove 511 facing upwards, inject adhesives such as epoxy resin, acrylic resin, and polyurethane into the second adhesive groove 511. Wait for the adhesive to cure. After the adhesive cures, the needle core 600 is fixed in the second adhesive groove 511 by the adhesive. The first trigger button 700 and the first mounting block 300 are pre-engaged. The first elastic element 331 is sleeved onto the first snap-fit ​​part 330. The second trigger button 800 and the second mounting block 500 are pre-assembled. The second elastic element 531 is sleeved onto the second snap-fit ​​part 530. Then, they are placed into the lower housing 202. Then, the upper housing 201 is connected to the lower housing 202. The mounting housing 200 is snapped into the outer housing 100. The first trigger button 700 and the second trigger button 800 are not easily separated from the mounting housing 200 during installation, which effectively improves the installation speed.

[0057] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A biopsy needle core needle tube assembly, characterized by, The utility model relates to a pen needle device, including: An outer shell (100); A mounting shell (200) arranged in the outer shell (100), wherein the mounting shell (200) is provided with a containing cavity (210); A first mounting block (300) slidingly arranged in the containing cavity (210), wherein the first mounting block (300) is connected with a needle tube (400) extending out of the outer shell (100); A second mounting block (500) slidingly arranged in the containing cavity (210), wherein the second mounting block (500) is connected with a needle core (600) extending out of the outer shell (100), the needle core (600) is arranged in the needle tube (400), and the movement direction of the first mounting block (300) is parallel to the movement direction of the second mounting block (500); A first trigger button (700) slidingly arranged between the outer shell (100) and the mounting shell (200), wherein the first trigger button (700) is snap-connected with the first mounting block (300); A second trigger button (800) slidingly arranged between the outer shell (100) and the mounting shell (200), wherein the second trigger button (800) is snap-connected with the second mounting block (500).

2. The biopsy needle mandrel needle tube assembly of claim 1, wherein: The first mounting block (300) comprises a first connecting portion (310) and a first sliding limiting portion (320), both sides of the mounting shell (200) are provided with sliding holes (220), the first sliding limiting portion (320) extends into the sliding hole (220) and can slide along the sliding hole (220), the first connecting portion (310) is connected with the first sliding limiting portion (320), and the first connecting portion (310) is used for fixing the needle tube (400).

3. The biopsy needle firing cannula assembly of claim 2, wherein: The side wall of the sliding hole (220) is provided with an auxiliary sliding groove (221), and the first sliding limiting portion (320) is connected with an auxiliary sliding block (321) embedded in the auxiliary sliding groove (221).

4. The biopsy needle mandrel needle tube assembly of claim 2, wherein: A first glue groove (311) is arranged in the first connecting portion (310), the needle tube (400) passes through the first glue groove (311) in the first connecting portion (310), and an adhesive for fixing the needle tube (400) is arranged in the first glue groove (311).

5. The biopsy needle firing cannula assembly of claim 4, wherein: The first glue groove (311) is provided with a first glue fixing block (312).

6. The biopsy needle firing cannula assembly of claim 2, wherein: The first mounting block (300) comprises a first buckle portion (330), the first buckle portion (330) is connected with the first sliding limiting portion (320), the mounting shell (200) is formed with a first buckle opening (230) for fixing the first buckle portion (330), a first elastic member (331) is arranged outside the first buckle portion (330), the first elastic member (331) is used for pushing the needle tube (400) to move towards the direction of extending out of the outer shell (100), and the first trigger button (700) is used for driving the needle tube (400) to move towards the direction of retracting into the outer shell (100).

7. The biopsy needle firing cannula assembly of claim 6, wherein: The first connecting part (310) is provided with a plurality of first abutting parts (313) on the side surface, and the outer peripheral wall of the first abutting part (313) abuts against the first elastic member (331).

8. The biopsy needle firing cannula assembly of claim 2, wherein: The second mounting block (500) comprises a second connecting part (510) and a second sliding limiting part (520), the second sliding limiting part (520) extends into the sliding hole (220) and can slide along the sliding hole (220), the second connecting part (510) is connected with the second sliding limiting part (520), and the second connecting part (510) is used for fixing the needle core (600).

9. The biopsy needle firing cannula assembly of claim 8, wherein: The second connecting part (510) is provided with a second glue groove (511), the needle core (600) passes through the second glue groove (511) in the second connecting part (510), and the second glue groove (511) is provided with an adhesive for fixing the needle core (600).

10. The biopsy needle firing cannula assembly of claim 9, wherein: The second mounting block (500) comprises a second buckle part (530), the second buckle part (530) is connected with the second sliding limiting part (520), the installation shell (200) is formed with a second buckle opening (240) for fixing the second buckle part (530), the second buckle part (530) is provided with a second elastic member (531) on the outside, the second elastic member (531) is used for pushing the needle core (600) to move towards the direction of extending out of the outer shell (100), and the second trigger button (800) is used for driving the needle core (600) to move towards the direction of retracting into the outer shell (100).

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