CN111214729A

CN111214729A - Injection needle

Info

Publication number: CN111214729A
Application number: CN201910364485.5A
Authority: CN
Inventors: 张立波
Original assignee: Tianjin Huahong Technology Co Ltd
Current assignee: Tianjin Huahong Technology Co Ltd
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2020-06-02
Anticipated expiration: 2039-04-30
Also published as: CN111214729B

Abstract

The invention relates to an injection needle, comprising: a needle holder having a cannula; a first sheath, one end of which is connected to one end of the needle holder to form an accommodating space between the first sheath and the needle holder, and the other end of which is provided with a first opening; one end of the second sheath is positioned in the accommodating space, the other end of the second sheath is provided with a second opening, a part of the second sheath can be axially and slidably positioned in the accommodating space, and the tube needle is suitable for being exposed through the second opening; a spring adapted to provide a spring force to axially move the second sheath toward the outside of the accommodating space, the second sheath being adapted to retract into the accommodating space against the spring force to expose the stylet based on an external force. The other end of the first sheath is provided with a positioning piece extending towards one end of the first sheath; the other end of the second sheath is provided with a positioning groove, and the positioning groove is matched with the positioning piece at the installation positions of the first sheath and the second sheath to prevent the second sheath from rotating relative to the first sheath; and based on the second sheath moving towards the containing space, the positioning groove and the positioning piece can be separated and matched.

Description

Injection needle

Technical Field

The embodiment of the invention relates to the field of medical instruments, in particular to an injection needle.

Background

The injection needle matched with the insulin injection pen in the market at present comprises a large sheath, a small sheath, a needle seat, a tube needle and dialysis paper, wherein the needle point of the tube needle is always exposed after the large sheath and the small sheath are removed, the infection probability can be increased if certain patients use the injection needle for a second time, or the needle after use easily accidentally injures others to cause cross infection.

Further, the following scheme has been proposed: during depression of the small sheath, the small sheath moves axially while rotating circumferentially to a circumferential position that helps prevent inward axial movement of the small sheath back to the axially extended position. However, in this solution, since one end of the small sheath is located outside the large sheath, there is a possibility that: before the needle is used, the small sheath is rotated due to misoperation to cause the needle to be invalid.

Disclosure of Invention

The present invention has been made to mitigate or solve at least one of the above-mentioned problems.

According to an aspect of an embodiment of the present invention, there is provided a disposable injection needle including:

the needle seat is provided with a tube needle axially extending through the needle seat;

a first sheath, one end of which is suitable for being connected to one end of the needle base so as to form an accommodating space between the first sheath and the needle base, and the other end of which is provided with a first opening;

a second sheath, one end of the second sheath is positioned in the accommodating space, the other end of the second sheath is provided with a second opening which extends out from the first opening, a part of the second sheath is positioned in the accommodating space in an axially sliding way, and the tube needle is suitable for being exposed through the second opening;

a spring adapted to provide a spring force to axially move the second sheath out of the receiving space, the second sheath adapted to retract into the receiving space against the spring force to expose the stylet based on an external force, wherein:

the other end of one of the first sheath and the second sheath is provided with a positioning piece with axial extension length, and the other end of the other one of the first sheath and the second sheath is provided with a positioning groove;

at the installation positions of the first sheath and the second sheath, the positioning groove is matched with the positioning piece to prevent the second sheath from rotating relative to the first sheath; and is

Based on the second sheath moving towards the containing space, the positioning groove and the positioning piece are suitable for being disengaged.

Optionally, the other end of the first sheath is provided with a positioning element extending towards one end of the first sheath, and the other end of the second sheath is provided with a positioning groove

Optionally, the other end of the second sheath is provided with a first protrusion and a second protrusion spaced apart from each other, the first side of the first protrusion and the first side of the second protrusion defining the positioning slot therebetween.

Optionally, the second sheath has a small diameter portion and a large diameter portion connected to each other in the axial direction, the small diameter portion and the large diameter portion forming a step surface at the connection, wherein the small diameter portion is adapted to axially protrude from the first opening to the outside of the first sheath, and a distal end of the small diameter portion has the second opening and a second blocking surface perpendicular to the axial direction and defining the second opening; the other end of the first sheath has a first blocking face defining a first outlet; the step surface is suitable for being in abutting fit with the first blocking surface, and the large-diameter part can be axially and slidably located in the accommodating space.

Optionally, the first protrusion or the second protrusion has a first top surface coplanar with the step surface; and the inner end face of the other end of the first sheath is provided with an extension piece extending towards one end of the first sheath, and the extension piece is abutted against the first top face when the positioning piece is matched in the positioning groove.

Optionally, a portion of the small-diameter portion of the second sheath adjacent to the step surface is provided with an identification portion different from other portions of the small-diameter portion.

Optionally, the second sheath has the installation position and a locked position after use; the inner wall of the first sheath is provided with a locking rib extending in the axial direction; in the locked position, the first and second projections are circumferentially located between the positioning member and the locking rib to prevent rotation of the second sheath relative to the first sheath.

Optionally, in the locking position, the second side of the first protrusion is adjacent to or connected to the positioning element, and the second side of the second protrusion is adjacent to or connected to the locking rib.

Optionally, the end of the positioning element has a first guide surface; and the first bulge is provided with a second guide surface, and the first guide surface and the second guide surface are mutually matched inclined surfaces so as to guide the positioning piece to move towards the second side of the first bulge.

Optionally, the inner wall of the first sheath is provided with a first guide rib extending in the axial direction, the first guide rib constituting the locking rib.

Optionally, the positioning groove is arranged at an inner edge of the first opening at the other end of the first sheath, the positioning element is a convex rib arranged at the outer side of the other end of the second sheath, and the convex rib and the end face at the other end of the second sheath have a predetermined axial distance.

Further optionally, one end of the end face of the rib remote from the other end of the second sheath has an increased height. Or further optionally, the second sheath has a small diameter portion and a large diameter portion connected to each other in the axial direction, the small diameter portion and the large diameter portion forming a step surface at the connection, wherein the small diameter portion is adapted to axially project from the first opening out of the first sheath, and a distal end of the small diameter portion has the second opening and a second blocking surface perpendicular to the axial direction and defining the second opening; the other end of the first sheath has a first blocking face defining a first outlet; the step surface is suitable for being in abutting fit with the first blocking surface, and the large-diameter part can be axially and slidably positioned in the accommodating space; the convex rib is arranged on the small-diameter part.

Optionally, the first sheath is provided with a second extension piece extending inwards in a direction away from the first blocking face; the end part of the second extending piece is abutted against the step surface at the mounting position after the injection needle is assembled, and the distance of the second sheath extending from the first sheath is a first distance at the mounting position; and in the position after the injection needle is used, the second extending piece is positioned at the position which is not abutted against the step surface, and in the position after the injection needle is used, the distance of the second sheath extending out of the first sheath is a second distance which is larger than the first distance.

Optionally, in the injection needle, the second sheath is provided with a sheath guiding portion, the needle base or the first sheath is provided with a guiding matching portion, and the sheath guiding portion is matched with the guiding matching portion to guide the second sheath to rotate in the circumferential direction based on the axial movement of the second sheath into the accommodating space.

Optionally, the first sheath is provided with a blocking part, the second sheath is provided with a buckling part, and the blocking part and the buckling part are arranged as follows: allowing the catch to pass the stop in an axial direction towards the second opening and providing resistance to the catch passing the stop in an axial direction away from the second opening.

Optionally, a limiting guide groove is formed in the inner wall of the first sheath, and the blocking piece is arranged in the limiting guide groove; and based on the rotation of the second sheath in the circumferential direction, the buckle part enters the limiting guide groove. Furthermore, the inner wall of the first sheath is provided with a first guide rib, a second guide rib and a third guide rib which are spaced from each other and extend in parallel in the axial direction, a first guide groove is formed between the first guide rib and the second guide rib, a second guide groove is formed between the second guide rib and the third guide rib, and the second guide groove forms the limiting guide groove; based on the circumferential rotation, the fastener is suitable for moving from the first guide groove to the second guide groove in the circumferential direction. Furthermore, corresponding to the circumferential movement, a surface which is convenient for the clamping piece to climb over the second guide rib is arranged on one side, facing the first guide groove, of the second guide rib; and/or one side of the buckle piece facing the second guide rib is provided with a surface facilitating the buckle piece to climb over the second guide rib. Still further, a cross section of a portion of the second guide rib from the blocking member to the first opening is rectangular, a cross section of a portion of the second guide rib from the blocking member to the one end of the first sheath is right-angled trapezoidal, and a hypotenuse of the right-angled trapezoidal faces the first guide groove.

Optionally, a guide matching part is arranged on the needle seat; a needle seat guide part is arranged on the needle seat, a needle seat guide inclined plane is arranged at the end part of the needle seat guide part, and the needle seat guide inclined plane forms the guide matching part; the second sheath comprises a sheath guide arm which is suitable for moving axially and circumferentially in the needle seat guide part, a matching inclined surface matched with the needle seat guide inclined surface is arranged at the end part of the sheath guide arm, and the matching inclined surface forms the sheath guide part; and the distance or width of the needle seat guide part in the circumferential direction is larger than the distance or width of the sheath guide arm in the circumferential direction, so as to allow the second sheath to complete the circumferential rotation. Furthermore, the end part of the needle seat guide part is also provided with a pressing stop surface connected with the needle seat guide inclined plane; the end part of the sheath guide arm is provided with a matching blocking surface connected with the matching inclined surface, and after the second sheath completes the circumferential rotation, the matching blocking surface is abutted to the pressing blocking surface to prevent the second sheath from further moving axially.

Optionally, the second sheath is provided with a sheath limiting arm, and the end of the sheath limiting arm is provided with the fastener. Further, one side of the clamping part facing the second opening is provided with a compliant surface, and the side opposite to the compliant surface of the clamping part in the axial direction is provided with a blocking surface; the blocking part is provided with a blocking surface matched with the blocking surface of the clamping part on one side facing the first opening; or one side of the blocking piece facing the first opening is provided with a blocking surface matched with the blocking surface of the clamping piece, and one side of the blocking piece opposite to the blocking surface of the blocking piece in the axial direction is provided with a compliant surface matched with the compliant surface of the clamping piece.

Optionally, a guide groove and a limiting guide groove are arranged on the first sheath; the first sheath is provided with the guide matching part, and the guide matching part is an inclined guide groove or an arc-shaped guide groove which is used for connecting the end part of the guide groove and the end part of the limiting guide groove; the second sheath comprises a sheath guide arm, the buckle piece is arranged at the end part of the sheath guide arm, and the blocking piece is arranged in the limiting guide groove; and based on the circumferential rotation, the buckling piece enters the limiting guide groove through the inclined guide groove or the arc-shaped guide groove.

Optionally, the injection needle has two positioning members, and the two positioning members are arranged opposite to each other in the radial direction; the injection needle is provided with two positioning grooves which are arranged oppositely in the radial direction.

According to the embodiment of the present invention, the second sheath of the injection needle in a standby state can be prevented from being rotated due to a wrong operation by the cooperation of the positioning member and the positioning groove.

In addition, according to the embodiment of the present invention, the needle tip of the stylet is prevented from being exposed to the outside again after one use by the design of the internal structure of the injection needle assembly.

Drawings

FIGS. 1a, 1b, 1c, 1d are front, bottom, cross-sectional and perspective views, respectively, of a large sheath (third sheath) according to an exemplary embodiment of the present invention;

fig. 2a, 2b, 2c, 2d, 2e are front, bottom, left, cross-sectional and perspective views, respectively, of a hub according to an exemplary embodiment of the present invention;

FIGS. 3a, 3b, 3C, 3D, 3e are front, bottom, C-C, D-D, and perspective views, respectively, of an auxiliary sheath (first sheath) according to an exemplary embodiment of the present invention; 3 FIGS. 33 3f 3, 33 3g 3 are 3a 3 front 3 view 3 in 3 another 3 direction 3 and 3 an 3 exemplary 3 cross 3- 3 sectional 3 view 3A 3- 3A 3 of 3 the 3 auxiliary 3 sheath 3( 3 first 3 sheath 3) 3 of 3 FIG. 33 3a 3, 3 respectively 3, 3 showing 3a 3 positioning 3 member 3; 3

FIGS. 4a, 4b, 4c, 4d, 4E are front, top, E-E cross-sectional, left and perspective views, respectively, of a small sheath (second sheath) according to an exemplary embodiment of the present invention;

FIG. 5 is a view of a spring according to an exemplary embodiment of the present invention;

FIG. 6 is a front view of a dialysis paper according to an exemplary embodiment of the present invention;

FIGS. 7a, 7B, 7c are a first front view, a first cross-sectional view and a perspective view, respectively, of an injection needle with a large sheath removed according to an exemplary embodiment of the present invention, and FIGS. 7d, 7e, 7F are a second front view, a cross-sectional view B-B, and a cross-sectional view F-F, respectively, of an injection needle with a large sheath removed according to an exemplary embodiment of the present invention, wherein the first sheath and the second sheath are assembled;

FIG. 8 is a perspective view of an injection needle according to an exemplary embodiment of the present invention;

FIGS. 9a, 9b, 9c, 9d are front, J-J, left and K-K cross-sectional views, respectively, of an injection needle just contacting the skin of a user with the large sheath removed, according to an exemplary embodiment of the present invention;

FIGS. 10a, 10b, 10c, 10d are front, U-U, left and L-L cross-sectional views, respectively, of an injection needle tip penetrating a user's skin with the large sheath removed, according to an exemplary embodiment of the present invention;

FIGS. 11a and 11b are a front view and a cross-sectional view M-M showing a spring state, respectively, of a needle tip of a tubular needle penetrating a user's skin with a large sheath removed, according to an exemplary embodiment of the present invention;

12a, 12b, 12c are front and AM-AM cross-sectional views and AL-AL cross-sectional views, respectively, showing the spring state after completion of injection of the needle in accordance with an exemplary embodiment of the present invention;

FIG. 13 schematically illustrates the displacement of the small sheath from beginning retraction to rotation to a stop point;

FIG. 14 is a perspective view of the injection needle with the large sheath removed and the first and second sheaths assembled, showing the positioning member and the positioning slot in position relative to one another and with some of the components omitted from FIG. 14 for clarity;

FIG. 15 is a perspective view of an injection needle according to an exemplary embodiment of the present invention with the second sheath retracted into the first sheath in use, and with the positioning member and positioning slot shown primarily in FIG. 15 and with some parts omitted for clarity;

FIG. 16 is a perspective view of an injection needle according to an exemplary embodiment of the present invention with the second sheath repositioned after use, and for clarity, FIG. 16 shows primarily the relative positions of the positioning member and the positioning slot, with some components omitted;

FIG. 17 is a perspective view of an injection needle according to an exemplary embodiment of the present invention, wherein the second sheath is further moved axially inwardly based on the snap 47 riding over the stop 311, and the relative positions of the positioning member and the positioning slot are mainly shown in FIG. 17 with parts omitted for clarity;

fig. 18 is a perspective view of an injection needle according to an exemplary embodiment of the present invention, in which the second sheath is moved further axially inwardly by the snap 47 across the blocking member 311, and the first projection and the second projection are located between the positioning member and the first guide rib, and for clarity, the relative positions of the positioning member and the positioning groove are mainly shown in fig. 18, and some parts are omitted;

fig. 19a-19d are schematic views of an injection needle according to an exemplary embodiment of the present invention, fig. 19a shows a rib and a detent in an installed ready-to-use state, fig. 19b shows a rib and a detent in a post-use state, fig. 19c shows a rib provided in a second sheath, and fig. 19d shows a first sheath with a detent and a second extension, fig. 19a-19d are views showing the rib and the detent and the second extension and the top surface, and other structures or components are not shown.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings. In the specification, the same or similar reference numerals denote the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention and should not be construed as limiting the invention.

Referring first to the drawings, a disposable needle according to an exemplary embodiment of the present invention will be described in detail, it being noted that some features or elements in the drawings are not specifically shown for clarity of illustration. As shown in the drawings, a disposable injection needle according to an embodiment of the present invention includes:

a hub 20, as shown in fig. 2a-2d, the hub 20 having a stylet 70 extending axially therethrough;

a first sheath 30, as shown in fig. 3a-3e and fig. 7a-7c, one end of said first sheath 30 being adapted to be connected to one end of said needle hub 20 to form a receiving space R between the first sheath 30 and the needle hub 20, the other end of said first sheath 30 having a first opening 314;

a second sheath 40, as shown in fig. 4a-4e and 7a-7c, one end of the second sheath 40 is located in the accommodating space R, the other end of the second sheath 40 has a second opening 41 extending from the first opening 314, and a part of the second sheath 40 is axially slidably located in the accommodating space R, and the trocar 70 is adapted to be exposed through the second opening 41;

a spring 50 (see fig. 5), said spring 50 being adapted to provide a spring force for axially moving the second sheath 40 towards the outside of the receiving space, said second sheath 40 being adapted to retract towards said receiving space R against the spring force based on an external force for exposing said cannula 70,

wherein:

as shown in fig. 3g, the other end of the first sheath 30 is provided with a positioning member 316 extending toward one end of the first sheath;

the other end of the second sheath 40 is provided with a positioning groove 413 (see fig. 4a), and in the installation position of the first sheath 30 and the second sheath 40 (see fig. 14), the positioning groove 413 is matched with the positioning piece 316 to prevent the second sheath 40 from rotating relative to the first sheath 30; and is

The positioning slot 413 and the positioning member 316 are adapted to disengage based on the second sheath 40 moving toward the receiving space.

As shown in fig. 4a, the other end of the second sheath 40 is provided with a first protrusion 419 and a second protrusion 420 spaced apart from each other, a first side of the first protrusion 419 and a first side of the second protrusion 420 defining the positioning slot 413 therebetween.

With further reference to fig. 4a-4e, the second sheath has a small diameter portion and a large diameter portion connected to each other in the axial direction, the small diameter portion and the large diameter portion forming a step surface 46 at the connection (see fig. 4e), wherein the small diameter portion is adapted to axially protrude from the first opening 314 out of the first sheath (see fig. 7b, for example), and a distal end of the small diameter portion has the second opening 41 (see fig. 4e) and a second stop surface 43 (see fig. 4c) perpendicular to the axial direction and defining the second opening 41. The other end of the first sheath 30 has a first blocking face 33 (see fig. 3c) defining a first outlet 314.

As shown in fig. 4e, the first and

second protrusions

419, 420 have

top surfaces

414, 415, respectively, that are coplanar with the step surface 46. However, the top surface of only one of the first projection and the second projection may be coplanar with the step surface 46.

As shown in fig. 3g, the inner end surface of the other end of the first sheath 30 is provided with an extension 317 extending towards (downward in the figure) one end of the first sheath, and the extension 317 abuts against the

top surface

414 or 415 when the positioning member is fitted in the positioning groove 413 (see fig. 14 for example), and in an exemplary embodiment, the top surface 414 abuts against the extension 317 as shown in fig. 7e and 14. The extension may also abut the top surface 415. In the illustrated example, the extension member 317 is directly joined or integral with the positioning member 316 as part 315 (see fig. 3g), or it may be separate (e.g., as in the embodiment shown in fig. 19a-19d below). These varied embodiments are within the scope of the invention.

In the absence of extension 317 or after needle use as described below, step surface 46 is adapted to abuttingly engage first blocking surface 33 to prevent further extension of second sheath 40 beyond first sheath 30.

In an alternative embodiment, as shown in fig. 4e, a portion of the small diameter portion of the second sheath 40 adjacent to the step surface 46 is provided with a recognition portion 418 different from other portions of the small diameter portion. The identifying portion 418 may be a portion that is painted with another color or provided with another mark. In embodiments of the present invention, the identification portion 418 may provide a status differential display of needle use or non-use. The identification portion 418 may be equally applicable to the example shown in fig. 19a-19 b.

In the assembled and unused state of the first and second sheaths, as shown in fig. 7e, extension 317 abuts top surface 414 and non-stepped surface 46 abuts first stop surface 33 so that identification portion 418 can be located within the receiving space and is not visible to the user. After use of the needle, as will be described later, when the first and second sheaths are relatively rotated, extension 317 does not abut top surface 414, but rather step surface 46 abuts first stop surface 33, thereby exposing identification 418.

As mentioned later, in an exemplary embodiment of the invention, pressing the second sheath in use causes the second sheath to rotate in the circumferential direction while moving axially inwardly. The invention correspondingly provides a technical scheme for preventing the second sheath from further rotating circumferentially based on pressing after the needle is used.

As previously mentioned, the second sheath has an installed position as shown in fig. 7 e.

As shown in fig. 18, the second sheath is in a locked position in which the second sheath is not allowed to rotate further in a particular direction in the circumferential direction.

As shown in fig. 18, the first sheath is provided with the locking rib 35, and the first protrusion 419 and the second protrusion 420 are circumferentially located between the positioning member 316 and the locking rib 35.

Further, as shown in fig. 18, in the locking position, the second side 416 (left side in fig. 18, see fig. 4a-4b) of the first protrusion 419 is adjacent to or connected to the positioning member 316, and the second side 417 (right side in fig. 18, see fig. 4a-4b) of the second protrusion 420 is adjacent to or connected to the locking rib 35. The locking rib 35 may be constituted by a first guide rib 35 mentioned later.

As shown in fig. 3g, the end of the positioning member 316 has a first guiding surface 318. As shown in fig. 4a, the first protrusion 419 has a second guiding surface 421, and the first guiding surface 318 and the second guiding surface 421 are mutually matched slopes (see fig. 17, for example) to guide the positioning member 316 to move towards the second side 416 of the first protrusion 419 (including relative movement due to the second sheath movement). The boot process may be, for example, from the state of fig. 16 to the state of fig. 17, and to the state of fig. 18.

It should also be noted that the positioning slot and positioning member are not limited to the examples of fig. 4a and 3 g.

In the embodiment of the present invention, the positioning member 316 may extend from the top end surface of the first sheath 30, and may also extend from the side wall of the first sheath 30, which is within the protection scope of the present invention.

It should be noted that in the present invention, the positioning groove may be formed by two adjacent protrusions spaced apart as shown in fig. 4a, however, the positioning groove may have other forms as long as it can form a fit with the positioning member, and these are within the protection scope of the present invention.

Further, the positioning groove is not limited to be provided on the second sheath 40, and accordingly, the positioning member is not limited to be provided on the first sheath 30. As shown in fig. 19a, the positioning groove is disposed at an inner edge of the first opening at the other end of the first sheath, the positioning element is a rib disposed at an outer side of the other end of the second sheath, and the rib has a predetermined axial distance from an end surface of the other end of the second sheath. In fig. 19a, the ribs are thus free of detents because of the predetermined axial distance, and also allow the second sheath to extend a length after use such that the second sheath prevents the stylet from being exposed.

Further, although not shown, an end of the end surface of the rib remote from the other end of the second sheath has an increased height. Thus, based on the increased height (forming a boss) arranged at one end of the convex rib far away from the end surface, in the installation state, the boss is abutted against a first blocking surface (mentioned later) at the first opening of the first sheath, so that the second sheath can be prevented from further extending out; and based on the predetermined axial distance, the second sheath may be allowed to extend a length after use such that the second sheath prevents the stylet from being exposed. In the case where the second sheath is rotated relative to the first sheath after use, the end of the rib adjacent the end face prevents the second sheath from extending further.

Although not shown, in the case where the rib is not provided with the boss, the second sheath may adopt the aforementioned structure of the large diameter portion and the small diameter portion.

19a-19d, the first sheath 30 is provided with a second extension 320 extending inwardly in a direction away from the first blocking surface 33; in the assembled mounting position of the injection needle, as shown in fig. 19a, the end of the second extension 320 abuts against the step surface 46, and in the mounting position, the second sheath 40 extends from the first sheath 30 by a first distance; and in the position after use of the injection needle, as shown in fig. 19b, the second extension 320 is in a position not abutting against the step surface 46, and in the position after use, the second sheath 40 extends from the first sheath 30 by a second distance, and the second distance is greater than the first distance.

In an unused state where the first jacket and the second jacket are assembled, the step surface 46 does not abut against the first blocking surface 33, so that the identification portion 418 can be located within the accommodation space without being observed by a user. However, after the needle is used and the first sheath and the second sheath are relatively rotated, the second extending member 320 does not abut against the step surface, but the step surface 46 abuts against the first blocking surface 33, and the identification portion 418 is exposed.

In the present invention, since the positioning member is inserted into the positioning groove as shown in fig. 14 or 19b in the case where the first sheath 30 and the second sheath 40 are assembled, it is possible to prevent: prior to use, first sheath 30 and second sheath 40 fail because of the premature entry of stop arm 44 into stop channel 32 due to rotation of the second sheath relative to the first sheath as a result of a malfunction.

Referring to fig. 2a-2d, 4a-4e, 9a-9d, 10a-10c, in an exemplary embodiment, the second sheath 40 is provided with a sheath guide 48, and the needle mount 20 is provided with a guide engagement portion 210, the sheath guide 48 engaging the guide engagement portion 210 to guide the second sheath 40 to rotate in a circumferential direction based on the second sheath 40 moving axially into the receiving space R.

As shown in fig. 9a to 9d, the first sheath 30 is provided with a stopper 311, and as shown in fig. 4a to 4e, the second sheath 40 is provided with a latch 47, and the stopper 311 and the latch 47 are arranged to: allowing the latch 47 to pass through the stopper 311 in an axial direction toward the second opening 41 and preventing the latch 47 from passing through the stopper 311 in an axial direction away from the second opening 41 to prevent the stylet 70 from being exposed through the second opening 41.

In the above embodiment, the second sheath 40 is moved axially into the receiving space R while being rotated circumferentially, at which point the cannula may be considered exposed and the injection operation may be performed or may be completed, as shown, for example, in fig. 9-11; thereafter, second sheath 40 is pushed outward by spring 50 so that catch 47 can pass over stop 311, at which point, as shown in fig. 12a, stylet 70 is inside second sheath 40, but in this case, even if second sheath 40 is pressed towards receiving space R, stylet 70 cannot be exposed because catch 47 is stopped by stop 311, as shown in fig. 12 c. Therefore, the technical scheme can prevent the tissue injection needle from being used for the second time and prevent the tube needle from being punctured by mistake or injuring people by mistake after the tissue injection needle is used.

In an alternative embodiment, as shown in fig. 3a to 3e, the inner wall of the first sheath 30 is provided with a limiting guide groove 32, and the blocking member 311 is arranged in the limiting guide groove 32; and the fastener 47 enters the limiting guide groove 32 based on the rotation of the second sheath 40 in the circumferential direction.

It should be noted, however, that the limiting guide groove herein can be broadly explained in addition to the situation shown in the drawings, for example, in the case that the blocking member extends a distance in the circumferential direction on the inner wall of the first sheath 30, the snap member 47 needs to pass through or be blocked by the blocking member in the axial direction, and in this case, the axial portion of the inner wall of the first sheath 30 where the blocking member is located can be referred to as the limiting guide groove even if there is no groove, and is within the protection scope of the present invention.

As shown in fig. 3a to 3e, the inner wall of the first sheath 30 is provided with a first guide rib 35, a second guide rib 39, and a third guide rib 34 spaced apart from each other and extending in parallel in the axial direction, a first guide groove 31 is formed between the first guide rib 35 and the second guide rib 39, and a second guide groove is formed between the second guide rib 39 and the third guide rib 34, the second guide groove constituting the limiting guide groove 32. Accordingly, the catch 47 is adapted to move circumferentially from the first guide groove 31 to the second guide groove based on the circumferential rotation.

In a further embodiment, in order to facilitate the passage of the catch 47 over the second guide rib 39, the following can be used: in correspondence to the circumferential movement, a side of the second guide rib 39 facing the first guide groove 31 is provided with a surface facilitating the snap 47 to climb over the second guide rib 39; and/or the side of the catch 47 facing the second guide rib 39 is provided with a surface facilitating the catch 47 to climb over the second guide rib 39. In a further alternative embodiment, the cross-section of the portion of the second guide rib 39 from the stopper 311 to the first opening (the portion above the stopper 311 in fig. 3c) is rectangular, the cross-section of the portion of the second guide rib 39 from the stopper 311 to the one end of the first sheath 30 (the portion below the stopper 311 in fig. 3c) is right-angled trapezoid, and the oblique side 310 of the right-angled trapezoid faces the first guide groove 31.

In an alternative embodiment, as shown in fig. 2a-2e, the needle hub 20 is provided with a guide engagement portion; a needle seat guide part is arranged on the needle seat 20, and a needle seat guide inclined plane forming the guide matching part 210 is arranged at the end part of the needle seat guide part; as shown in fig. 4a-4e and 9a-9d, the second sheath 40 comprises a sheath guide arm 45, the sheath guide arm 45 is adapted to move axially and circumferentially within the needle hub guide, and the end of the sheath guide arm 45 is provided with a mating ramp that mates with the needle hub guide ramp 210, the mating ramp constituting the sheath guide 48; and as shown in fig. 9b, the distance or width of the hub guide in the circumferential direction is greater than the distance or width of the sheath guide arm 45 in the circumferential direction to allow the second sheath 40 to complete the circumferential rotation.

In a further alternative embodiment, as shown in fig. 9b, the end of the needle holder guiding part is further provided with a pressing stop surface 211 connected with the needle holder guiding inclined surface 210; the end of the sheath guiding arm 45 is provided with a matching stopping surface 412 connected with the matching inclined surface 48, and after the second sheath completes the circumferential rotation, the matching stopping surface 412 abuts against the pressing stopping surface 211 to stop the second sheath 40 from further moving axially.

It should be noted that the engaging stop surface 412 and the pressing stop surface 211 may not be provided, and the present invention is also within the protection scope.

As shown in fig. 4a-4e, the second sheath 40 is provided with a sheath stopper arm 44, and the end of the sheath stopper arm 44 is provided with the latch 47.

In a further embodiment, the latch and the blocking member may be arranged so that the latch is easily blocked by the blocking member after passing over the blocking member.

Correspondingly, as shown in fig. 4a to 4e, the latch 47 is provided with a compliant surface 410 on the side facing the second opening (in fig. 4a, the side facing upwards), and a blocking surface 411 on the side opposite to the compliant surface in the axial direction, where the compliant surface 410 may be a surface facilitating passage and the blocking surface 411 is a surface preventing passage, in this embodiment, the compliant surface may be an inclined direction and the inclined direction is adapted to the moving direction, and the blocking surface may also be an inclined surface, but the inclined direction is opposite to the moving direction.

Correspondingly, as shown in fig. 3a to 3e, the blocking member 311 is provided with a blocking surface 313 at a side facing the first opening (at an upper side of the blocking member in fig. 3 d) for cooperating with the blocking surface 411 of the locking member 47; alternatively, the blocking element 311 is provided with a blocking surface 313 on the side facing the first opening (the upper side of the blocking element in fig. 3 d) for cooperating with the blocking surface 411 of the snap 47, and the blocking element 311 is provided with a compliant surface 312 for cooperating with the compliant surface 410 of the snap 47 on the side axially opposite to its own blocking surface 313 (the lower side of the blocking element in fig. 3 d).

Further, in order to facilitate the passage of the catch 47 over the guide rib 39, in an alternative embodiment, the side of the catch 47 facing the guide rib 39 when in the first guide groove 31 is provided with a catch slope 49.

Although not shown, in an alternative embodiment, a guide fit may be provided on the first sheath. Specifically, a guide groove and a limiting guide groove are arranged on the first sheath; the first sheath is provided with the guide matching part, and the guide matching part is an inclined guide groove or an arc-shaped guide groove which is used for connecting the end part of the guide groove and the end part of the limiting guide groove; the second sheath comprises a sheath guide arm, the buckle piece is arranged at the end part of the sheath guide arm, and the blocking piece is arranged in the limiting guide groove; and based on the circumferential rotation, the buckling piece enters the limiting guide groove through the inclined guide groove or the arc-shaped guide groove. In the above embodiment, the first sheath guides the axial movement and circumferential rotation of the second sheath, and when the second sheath is pressed inward, the guide groove guides the axial movement of the second sheath, and as the axial movement, the sheath guide arm enters the inclined guide groove or the arc-shaped guide groove, and completes the circumferential rotation during the subsequent further axial movement, and then the sheath guide arm enters the limit guide groove.

The mounting of the spring 50 is explained below. As shown in fig. 2a-2e and fig. 7b, in the embodiment of the present invention, the first end of the needle holder 20 is provided with a spring-retaining post 22, the spring-retaining post 22 extends axially from the first end of the needle holder 20, and the cannula 70 extends axially through the spring-retaining post 22; as shown in fig. 7b, the other end of the second sheath 40 has a second blocking face 43 perpendicular to the axial direction and defining the second opening; the spring comprises a spring 50, one end of which is sleeved on the spring limiting column 22, and the other end of which pushes and presses the second blocking surface 43. It should be noted that the spring 50 does not have to abut against the end surface of the needle mount 20 from which the spring retention post extends, as long as one end of the spring can be fixed to the spring retention post. However, in a further embodiment, as shown in FIG. 7b, the spring 50 may be relatively loosely received over the spring retention post 22 to allow deformation throughout the length of the spring.

In alternative embodiments, other arrangements of the spring may be used. For example, the spring is fixedly arranged on the first sheath at one end and on the needle seat at the other end, and the spring provides elastic pulling force for axially moving the needle seat towards the outside of the accommodating space.

In an alternative embodiment, one end of the second sheath 40 is located in the accommodating space R, the other end of the second sheath 40 has the second opening and protrudes from the first opening, and a part of the second sheath is axially slidably located in the accommodating space. In a further embodiment, as shown in fig. 4a-4e and 7b, the second sheath has a small diameter portion and a large diameter portion connected to each other in the axial direction, the small diameter portion and the large diameter portion forming a step surface 46 at the connection, wherein the small diameter portion is adapted to axially protrude from the first opening to the outside of the first sheath, the small diameter portion has a distal end having the second opening and a second stop surface perpendicular to the axial direction and defining the second opening, the step surface is adapted to be in abutting engagement with the first stop surface 33, and the large diameter portion is axially slidably located in the receiving space.

In an alternative embodiment, as shown in fig. 2a-2e, the first end of the needle hub is further provided with a mating circumferential surface 24; the one end of the first sheath 30 is adapted to be sleeved on the mating circumferential surface 24.

In an alternative embodiment, the injection needle may further comprise a third sheath 10, and the third sheath 10 is sleeved outside the needle holder 20, the first sheath 30 and the second sheath 40.

Optionally, a first anti-rotation design (for example, ribs or protrusions, or an interference fit structure) is provided at a joint between the first sheath and the needle base, and a second anti-rotation design (for example, anti-rotation ribs 12 or protrusions, or an interference fit structure) is provided at a joint between the third sheath and the needle base.

Optionally, the injection needle further comprises a dialysis paper 60 covering the opening of the third sheath.

Optionally, the other end of the needle hub 20 is provided with a connection means adapted to connect with an injection pen. As shown in fig. 2a-2e, the linking means may be a thread 28.

It is to be noted that, in the present invention, the ribs or the ribs may be regarded as being the same except for a slight difference in size, in other words, the ribs and the ribs may be regarded as having substantially the same meaning in the present invention.

An assembling process of the injection needle according to an exemplary embodiment of the present invention is described below with reference to the above-described structure.

The tube needle 70 passes through a through hole 21 preset in the needle seat 20, so that the tube needle 20 stays at a specified position, and the tube needle 70 and the needle seat 20 are fixed in a bonding mode and the like;

sleeving the spring 50 on the spring limiting column 22 of the needle seat 20, wherein one end of the spring is in contact with the spring limiting surface 23 of the needle seat 20, and the inner diameter of the spring is slightly larger than the outer diameter of the spring limiting column, so that the compression and extension of the spring are not limited;

the front end face 42 of the small sheath (the second sheath 40) is opposite to the small sheath limiting face (namely, the first blocking face) 33 of the auxiliary sheath (the first sheath 30), and the sheath limiting arm 44 of the small sheath is ensured to be aligned with the limiting arm guide groove (corresponding to the first guide groove 31) of the auxiliary sheath (the guide groove is formed by combining the guide rib 35 and the guide rib 39), and the front end face 42 of the small sheath is used for installing the small sheath into the auxiliary sheath through the through hole of the auxiliary sheath; the assembly composed of the small sheath and the auxiliary sheath is arranged on the needle base 20, at the moment, the guide rib 34 and the guide rib 35 of the auxiliary sheath are ensured to be arranged along the auxiliary sheath matching surface notch 25 of the needle base until the bottom surface 36 of the auxiliary sheath contacts the auxiliary sheath limiting plane 26 of the needle base 20, because the outer diameter of the auxiliary sheath matching surface 24 of the needle base is slightly larger than the inner diameter of the needle base matching surface 37 of the auxiliary sheath, the auxiliary sheath can be stably sleeved on the needle base 20, simultaneously, the other end of the spring which is pre-arranged at the outer side of the spring limiting column 22 of the needle base contacts with the spring limiting surface (corresponding to the second limiting surface 43) of the small sheath, simultaneously, the extending piece 317 is abutted against the top surface 414 (under the condition that the extending piece 317 is not arranged, the limiting surface (corresponding to the step surface 46) of the small sheath contacts with the small sheath limiting surface (the first blocking surface 33) of the auxiliary sheath), because the free, the small sheath is limited by the supporting force of the spring and the auxiliary sheath, so that the small sheath does not displace in the axial direction under the condition that the front end face 42 of the small sheath is not subjected to external force, as shown in detail in fig. 7a-7 c; at this time, as shown in fig. 14, the positioning member 316 is located in the positioning groove 413;

the opening 11 of the large sheath cavity is sleeved opposite to the small sheath needle outlet 41 of the assembly, the distance between the end surface 27 of the needle base and the front end surface 38 of the auxiliary sheath is slightly smaller than the distance between the end surface 13 of the large sheath opening and the shoulder 14 of the large sheath, so that the assembly can be completely accommodated in the large sheath without influencing the matching of the threads 28 in the needle base cavity and the insulin injection pen, the large sheath matching ribs 29 arranged on the surface of the needle base are symmetrically distributed along the central axis, the maximum distance is slightly larger than the inner diameter of the large sheath cavity, and the assembled large sheath can not fall off from the needle base and can be easily taken;

finally, the dialyzing paper is fixed on the opening end face of the jacket by means of bonding and the like, as shown in figure 8.

In an alternative embodiment, as shown in the figures, the second sheath 40 has two guides 42 and two retaining arms 46, wherein the two retaining arms 46 are arranged diametrically opposite each other and the two guides 42 are arranged diametrically opposite each other. As will be appreciated by those skilled in the art, the cooperating structure on the first sheath and the needle hub are correspondingly configured.

The operation of the injection needle according to the exemplary embodiment of the present invention will be described with reference to the above-described structure.

Firstly, the syringe needle is screwed with a syringe pen (not shown) after the dialyzing paper 60 is removed, in order to prevent the large sheath and the needle seat 20 from sliding to cause the screw connection is not firm, a rotation stopping rib 12 is arranged in the large sheath, and the rotation stopping rib 12 can interfere with a large sheath matching rib 29 of the needle seat to prevent the large sheath and the needle seat from sliding.

Secondly, the large sheath is taken down, the front end face 42 of the small sheath is aligned with the injection site of the patient, the small sheath retracts towards the inside of the auxiliary sheath at the moment of pressing down, the tube needle passes through the needle outlet 41 of the small sheath, and when the guide inclined plane (corresponding to the sheath guide part 48) of the guide arm 45 of the small sheath contacts with the guide surface (corresponding to the guide matching part 210) of the small sheath of the needle seat, as shown in fig. 9a to 9d, the limiting arm buckling part 47 longitudinally moves in the limiting arm guide groove (corresponding to the first guide groove 31).

Then, the small sheath is axially retracted and simultaneously rotated by a certain angle (equal to the central angle between the rib guide rib 34 and the guide rib 35) relative to the circumferential direction of the needle holder, as shown in fig. 10a to 10d, at which time the arm lock 47 is rotated to move longitudinally in the arm lock guide groove 32. Specifically, while the limit arm 44 of the small sheath moves axially into the inside of the auxiliary sheath in the limit arm guide groove (corresponding to the first guide groove 31) of the auxiliary sheath, under the driving of the guide arm (corresponding to the sheath guide arm 45), the limit arm latch 47 of the small sheath approaches the second guide rib 39 (the second guide rib 39 is axially divided into two sections, the section of the part near the front end surface is rectangular, the other section is in a right trapezoid shape, and the inclined surface 310 is opposite to the first guide rib 35) and tends to pass over the second guide rib), the contact surface of the limit arm latch 47 and the guide rib 39 is a latch inclined surface 49, when the contact part of the limit arm latch 47 and the second guide rib 39 is transited from a straight surface to the inclined surface 310, the latch 47 can easily pass over the second guide rib 39 and then stops in the limit arm limit guide groove 32 (composed of the second guide rib 39 and the third guide rib 34) of the auxiliary sheath, the axial movement is continued until the stop face of the small sheath (corresponding to the engagement stop face 412) comes into contact with the stop engagement face of the needle holder (corresponding to the press stop face 211), at which point the spring is compressed, see fig. 11a-11 b. At this time, the positional relationship between the positioning member 316 and the first protrusion 419 is as shown in fig. 15.

Fig. 13 schematically illustrates the displacement of the small sheath from the beginning of retraction to the point of rotation to stop, illustratively, the first step is retraction L1 (e.g., 7.8mm) first, with a retraction amount of L2 (e.g., 1.4mm) while rotating, for a total displacement of L1+ L2 (e.g., 9.2 mm).

Then, after the injection is finished, the needle head of the needle is pulled out to apply a reset force to the small sheath instantly by the spring, the small sheath limiting arm fastener 47 moves along the limiting arm limiting guide groove 32, the middle position of the limiting arm limiting guide groove 32 of the auxiliary sheath (which can just support the small sheath to avoid the exposure of the needle and is adjacent to one end of the rectangular section of the second guide rib) is provided with a limiting hanging table (corresponding to the blocking part 311), the hanging table and the first contact surface (corresponding to the compliant surface 312) of the limiting arm fastener 47 of the auxiliary sheath are forward, the second contact surface (corresponding to the blocking surface 313) is reverse, the first contact surface (corresponding to the compliant surface 410) of the limiting arm fastener 47 of the small sheath is also forward, the limiting arm 44 can slightly elastically deform to cross the limiting hanging table of the auxiliary sheath in the resetting process, the second contact surface (corresponding to the blocking surface 411) of the limiting arm fastener 47 of the small sheath is reverse, the angle and the size of the second contact surface of the limiting hanging platform of the auxiliary sheath are just consistent, if the injection needle is used again, when pressure is applied to the front end face 42 of the small sheath, the limiting arm buckling piece 47 of the small sheath is abutted against the limiting hanging platform of the auxiliary sheath, so that the injection needle is invalid, and the reference of the figures is 12a-12 c.

If the engagement between the catch 47 and the stopper 311 fails or is broken because the second sheath 40 is further pressed, the second sheath 40 is further axially moved inward in the state of fig. 16 up to the state of fig. 17 and then further to the state of fig. 18. In the state of fig. 18, the second sheath is in the locked position, the catch 47 engages the stop 311, and even if the second sheath 40 is further depressed and the sheath guide 48 (ramp) abuts the guide engagement 210 (ramp) on the needle mount and tends to rotate circumferentially, rotation relative to the first sheath 30 is prevented because the second sheath 40 is in the locked position, so that the second sheath 40 cannot be further depressed inwardly and is retracted back into the first sheath again. If the second sheath is not locked, it is rotated circumferentially relative to the first sheath under the torque of the external force, and the catch 47 enters the groove 31, so that the needle can be used a second time.

As previously mentioned, a further aspect of the present invention contemplates preventing further inward axial movement of the second sheath in the event that the engagement between catch 47 and stop 311 is broken, by employing a locked position in the circumferential direction with the second sheath that is not rotatable circumferentially relative to the first sheath.

As can be appreciated by those skilled in the art, in the present invention, when the second sheath is in the locked position in the circumferential direction and the sheath guide 48 (ramp) abuts the guide engagement portion 210 (ramp) on the needle hub, the needle tip is not exposed from the needle outlet of the second sheath.

Furthermore, by cooperating the inclined surface 318 and the inclined surface 421, it is possible to avoid: the top surface 414 is locked after being in direct contact with the positioning member 316, so that the second sheath 40 cannot be reset and is exposed to the tip or is used for the second time. The injection needle can be matched with an insulin injection pen to inject insulin subcutaneously for diabetics. As known to those skilled in the art, the injection needle of the present invention may also be used in conjunction with other injection pens or medical devices.

Although embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims

1. An injection needle comprising:

a spring adapted to provide a spring force to axially move the second sheath toward outside the accommodating space, the second sheath adapted to retract into the accommodating space against the spring force to expose the stylet based on an external force,

wherein:

2. The injection needle of claim 1, wherein:

the other end of the first sheath is provided with a positioning piece extending towards one end of the first sheath, and the other end of the second sheath is provided with a positioning groove.

3. The injection needle of claim 2, wherein:

the other end of the second sheath is provided with a first protrusion and a second protrusion spaced apart from each other, the detent being defined between a first side of the first protrusion and a first side of the second protrusion.

4. The injection needle of claim 3, wherein:

the second sheath has a small-diameter portion and a large-diameter portion which are connected to each other in the axial direction, the small-diameter portion and the large-diameter portion forming a step surface at the connection, wherein the small-diameter portion is adapted to axially project from the first opening out of the first sheath, and a distal end of the small-diameter portion has the second opening and a second blocking surface which is perpendicular to the axial direction and defines the second opening;

the other end of the first sheath has a first blocking face defining a first outlet;

the step surface is suitable for being in abutting fit with the first blocking surface, and the large-diameter part can be axially and slidably located in the accommodating space.

5. The injection needle of claim 4, wherein:

the first protrusion or the second protrusion has a first top surface coplanar with the step surface; and is

The inner end face of the other end of the first sheath is provided with an extension piece extending towards one end of the first sheath, and the extension piece is abutted to the first top face when the positioning piece is matched in the positioning groove.

6. The injection needle of claim 5, wherein:

the small-diameter portion of the second sheath is provided with an identification portion different from other portions of the small-diameter portion, adjacent to the step surface.

7. The injection needle of claim 3, wherein:

said second sheath having said installed position and a locked position after use;

the inner wall of the first sheath is provided with a locking rib extending in the axial direction;

in the locked position, the first and second projections are circumferentially located between the positioning member and the locking rib to prevent rotation of the second sheath relative to the first sheath.

8. The injection needle of claim 7, wherein:

in the locking position, the second side of the first protrusion is adjacent to or connected with the positioning piece, and the second side of the second protrusion is adjacent to or connected with the locking rib.

9. The injection needle of claim 8, wherein:

the end part of the positioning piece is provided with a first guide surface; and is

The first protrusion is provided with a second guide surface, and the first guide surface and the second guide surface are mutually matched inclined surfaces so as to guide the positioning piece to move towards the second side of the first protrusion.

10. The injection needle of claim 8, wherein:

the inner wall of the first sheath is provided with a first guide rib extending in the axial direction, the first guide rib constituting the locking rib.

11. The injection needle of claim 1, wherein:

the locating slot is arranged at the inner edge of the first opening at the other end of the first sheath, the locating piece is a convex rib arranged at the outer side of the other end of the second sheath, and the convex rib and the end face of the other end of the second sheath have a preset axial distance.

12. The injection needle of claim 11, wherein:

one end of the end face of the convex rib, which is far away from the other end of the second sheath, is provided with an increased height; or

The second sheath has a small-diameter portion and a large-diameter portion which are connected to each other in the axial direction, the small-diameter portion and the large-diameter portion forming a step surface at the connection, wherein the small-diameter portion is adapted to axially project from the first opening out of the first sheath, and a distal end of the small-diameter portion has the second opening and a second blocking surface which is perpendicular to the axial direction and defines the second opening; the other end of the first sheath has a first blocking face defining a first outlet; the step surface is suitable for being in abutting fit with the first blocking surface, and the large-diameter part can be axially and slidably positioned in the accommodating space; the convex rib is arranged on the small-diameter part.

13. The injection needle according to claim 4 or 12, wherein:

the first sheath is provided with a second extending piece extending inwards in the direction away from the first blocking surface;

the end part of the second extending piece is abutted against the step surface at the mounting position after the injection needle is assembled, and the distance of the second sheath extending from the first sheath is a first distance at the mounting position; and is

And in the position after the injection needle is used, the second extending piece is not abutted to the step surface, and in the position after the injection needle is used, the second distance is a second distance which is greater than the first distance and extends from the first sheath.

14. The injection needle according to any one of claims 1 to 13, wherein:

the second sheath is provided with a sheath guiding portion, the needle seat or the first sheath is provided with a guiding matching portion, and the sheath guiding portion is matched with the guiding matching portion to guide the second sheath to rotate in the circumferential direction based on the axial movement of the second sheath to the accommodating space.

15. The injection needle of claim 14, wherein:

the first sheath is provided with a blocking part, the second sheath is provided with a buckling part, and the blocking part and the buckling part are arranged into: allowing the catch to pass the stop in an axial direction towards the second opening and providing resistance to the catch passing the stop in an axial direction away from the second opening.

16. The injection needle of claim 15, wherein:

the inner wall of the first sheath is provided with a limiting guide groove, and the blocking piece is arranged in the limiting guide groove; and is

Based on the rotation of the second sheath in the circumferential direction, the buckle enters the limiting guide groove.

17. The injection needle of claim 16, wherein:

the inner wall of the first sheath is provided with a first guide rib, a second guide rib and a third guide rib which are spaced from each other and extend in parallel in the axial direction, a first guide groove is formed between the first guide rib and the second guide rib, a second guide groove is formed between the second guide rib and the third guide rib, and the second guide groove forms the limiting guide groove;

based on the circumferential rotation, the fastener is suitable for moving from the first guide groove to the second guide groove in the circumferential direction.

18. The injection needle of claim 17, wherein:

corresponding to the circumferential movement, one side of the second guide rib facing the first guide groove is provided with a surface facilitating the buckle to climb over the second guide rib; and/or

And a surface which is convenient for the buckling piece to climb over the second guide rib is arranged on one side of the buckling piece facing the second guide rib.

19. The injection needle of claim 17, wherein:

the cross section of the part, from the blocking piece to the first opening, of the second guide rib is rectangular, the cross section of the part, from the blocking piece to the one end of the first sheath, of the second guide rib is right trapezoid, the inclined edge of the right trapezoid faces the first guide groove, and optionally, a clamping piece inclined surface is arranged on one side, facing the second guide rib, of the clamping piece in the first guide groove.

20. The injection needle of claim 15, wherein:

the needle seat is provided with a guide matching part;

a needle seat guide part is arranged on the needle seat, a needle seat guide inclined plane is arranged at the end part of the needle seat guide part, and the needle seat guide inclined plane forms the guide matching part;

the second sheath comprises a sheath guide arm which is suitable for moving axially and circumferentially in the needle seat guide part, a matching inclined surface matched with the needle seat guide inclined surface is arranged at the end part of the sheath guide arm, and the matching inclined surface forms the sheath guide part; and is

The needle hub guide has a circumferential distance or width greater than a circumferential distance or width of the sheath guide arm to allow the second sheath to complete the circumferential rotation.

21. The injection needle of claim 20, wherein:

the end part of the needle base guiding part is also provided with a pressing blocking surface connected with the needle base guiding inclined plane;

the end part of the sheath guide arm is provided with a matching blocking surface connected with the matching inclined surface, and after the second sheath completes the circumferential rotation, the matching blocking surface is abutted to the pressing blocking surface to prevent the second sheath from further moving axially.

22. The injection needle of claim 16, wherein:

the second sheath is provided with a sheath limiting arm, and the end part of the sheath limiting arm is provided with the buckle piece.

23. The injection needle of claim 22, wherein:

the side, facing the second opening, of the clamping piece is provided with a compliant surface, and the side, opposite to the compliant surface of the clamping piece in the axial direction, of the clamping piece is provided with a blocking surface; and is

The blocking piece is provided with a blocking surface matched with the blocking surface of the clamping piece on one side facing the first opening; or one side of the blocking piece facing the first opening is provided with a blocking surface matched with the blocking surface of the clamping piece, and one side of the blocking piece opposite to the blocking surface of the blocking piece in the axial direction is provided with a compliant surface matched with the compliant surface of the clamping piece.

24. The injection needle of claim 15, wherein:

the first sheath is provided with a guide groove and a limiting guide groove;

the first sheath is provided with the guide matching part, and the guide matching part is an inclined guide groove or an arc-shaped guide groove which is used for connecting the end part of the guide groove and the end part of the limiting guide groove;

the second sheath comprises a sheath guide arm, the buckle piece is arranged at the end part of the sheath guide arm, and the blocking piece is arranged in the limiting guide groove; and is

Based on the circumferential rotation, the buckling piece enters the limiting guide groove through the inclined guide groove or the arc-shaped guide groove.

25. The injection needle of any one of claims 1 to 24, wherein:

the injection needle is provided with two positioning parts which are arranged oppositely in the radial direction;

the injection needle is provided with two positioning grooves which are arranged oppositely in the radial direction.