WO2021233201A1

WO2021233201A1 - Needle protection device and safety syringe

Info

Publication number: WO2021233201A1
Application number: PCT/CN2021/093641
Authority: WO
Inventors: 胡超宇
Original assignee: 普昂(杭州)医疗科技股份有限公司
Priority date: 2020-05-22
Filing date: 2021-05-13
Publication date: 2021-11-25
Also published as: CN111529825A; CN111529825B

Abstract

Disclosed are a needle protection device and a safety syringe. The needle protection device at least comprises a plug body (10), a sliding sleeve (30) and a non-return member (20), wherein the sliding sleeve (30) is arranged outside the plug body (10) in a sleeving manner and is movably connected to the plug body (10) in the axial direction; the sliding sleeve (30) is configured to have an initial state and an extended state relative to the plug body (10) in the axial direction; and the non-return member (20) is configured in such a way that when the sliding sleeve (30) is in the initial state, a disc-shaped body (21) is located between an end of the plug body (10) and an end of the sliding sleeve (30), and a rod-shaped body (22) is located in a containing space (70); and when the sliding sleeve (30) is in the extended state, the rod-shaped body (22) is separated from the containing space (70), and the non-return member (20) is supported between the end of the sliding sleeve (30) and the end of the plug body (10). The needle protection device and the safety syringe are simple in terms of structure, low in cost, convenient and fast to assemble, easily operated, and safe and reliable.

Description

Needle protection device and safety syringe

Technical field

The invention relates to the technical field of medical syringes, in particular to a needle protection device and a safety syringe.

Background technique

Disposable safety syringes are commonly used medical devices. In order to prevent accidental injury to the user by the syringe needle after use and prevent secondary use of the syringe, this type of syringe is usually equipped with a needle protection device to cover the needle after use to prevent the needle from accidentally injuring the user. The needle protection device also has a non-return structure to prevent the needle protection device from returning to the original position after covering the needle, thereby solving the problem of preventing secondary use.

technical problem

In the prior art, one of the types is a retractable needle safety syringe, and the structure of this type of syringe is relatively complicated and the cost is relatively high.

In addition, there is also a sliding sleeve type safety syringe in the prior art. For example, the Chinese utility model patent with the authorized announcement number CN203043181U discloses a sliding sleeve type needle protection device and a safety syringe. Compared with the automatic retracting type, the structure of the syringe has a simpler structure and a lower cost. In this structure, after the injection is completed, the sliding sleeve is first pushed to cover the needle, and then the sliding sleeve needs to be rotated to lock the sliding sleeve. The disadvantages of this sliding sleeve safety syringe are:

(1) The operation is complicated. After pushing the sliding sleeve, a rotation of the sliding sleeve is required, and a relatively large force needs to be applied when rotating the sliding sleeve to realize the locking function of the locking mechanism;

(2) It is unidirectional when rotating the sliding sleeve. If it is rotated in the opposite direction, the locking mechanism cannot be triggered. In actual operation, the user will not always remember the direction of rotation. It is recognized that when the user mistakenly rotates the sliding sleeve in the opposite direction, it may directly damage the needle protection device.

Technical solutions

The technical problem to be solved by the present invention is to provide a needle protection device and a safety syringe with an improved structure to solve the defects of the prior art.

In order to solve the above technical problems, the technical solution provided by the present invention is as follows: A needle protection device, which at least includes:

A plug body, the plug body is fixedly arranged;

A sliding sleeve, the sliding sleeve is sleeved outside the plug body and movably connected with the plug body in an axial direction, the sliding sleeve is configured to have an initial state and an extended state in the axial direction relative to the plug body; and

A non-return member, the non-return member includes a disc-shaped body and at least one rod-shaped body connected to the edge of the disc-shaped body and extending axially to one side of the disc-shaped body, the outer wall of the plug body and the sliding sleeve An accommodating space for accommodating the rod-shaped body is provided between the inner walls, and a step surface is arranged on the inner wall of the sliding sleeve and interacts with the free end of the rod-shaped body in the accommodating space, and the disc-shaped body is provided With a via hole, the axial projected area of the disc-shaped body is smaller than the axial projected area of the inner space of the sliding sleeve;

Wherein, the non-return member is configured such that: in the initial state of the sliding sleeve, the disc-shaped body is located between the end of the plug body and the end of the sliding sleeve, and the rod-shaped body is located in the accommodating space; In the extended state of the sleeve, the rod-shaped body is separated from the accommodating space, and the non-return member is supported between the end of the sliding sleeve and the end of the plug body.

In a preferred embodiment, the outer surface of the rod-shaped body is provided with an axially extending rib and is configured such that the outer surface of the rod-shaped body extends from the rib in a direction radially away from the inner surface of the sliding sleeve to The edge of the lateral side of the rod-shaped body.

In a preferred embodiment, the disc-shaped body has an asymmetric structure relative to the reference plane where the protruding ribs are located.

In a preferred embodiment, the sliding sleeve includes a first sliding sleeve and a second sliding sleeve that are buckled with each other.

In a preferred embodiment, an axial guide mechanism and/or a first initial limit mechanism are arranged between the sliding sleeve and the plug body.

In a preferred embodiment, the accommodating space at least includes:

An accommodating groove provided on the inner wall of the sliding sleeve; and

The containing plane is arranged on the outer wall of the plug body and configured to fit the inner surface of the rod-shaped body.

In a preferred embodiment, two symmetrical accommodation planes are provided on the plug body.

In a preferred embodiment, a second initial limit mechanism is provided between the non-return member and the plug body, and the second initial limit mechanism at least includes:

An elastic limiting member, which is arranged at the end of the plug body and covers at least a part of the containing space in the axial projection direction; and

The limiting groove is arranged at a position where the inner side surface of the rod-shaped body is close to the disc-shaped body and is configured to fit with the elastic limiting member.

In a preferred embodiment, a guiding mechanism is provided between the elastic limiting member and the limiting groove, and the guiding structure includes a first guiding inclined surface provided on the elastic member and a first guiding inclined surface provided in the limiting groove and connected to the first The second guide slope adapted to the guide slope.

A safety syringe, including at least:

A needle seat on which an injection needle is arranged; and

In the needle protection device, the plug body is fixedly connected to the needle seat, the injection needle passes through the through hole, and in the extended state of the sliding sleeve, the sliding sleeve covers the injection needle .

In the needle protection device of the present invention and the safety syringe containing the needle protection device, when the sliding sleeve is in the extended state and the rod-shaped body is separated from the accommodating space, the axial projection area of the disc-shaped body in the stopper is smaller than that of the sliding sleeve. The axial projected area of the inner space of the sleeve, the non-return member randomly overturns under the action of its own gravity, which causes the non-return member to be supported between the end of the sliding sleeve and the end of the plug body, which protects the needle from accidental puncture injuries. At the same time, the sliding sleeve is kept in the extended state and cannot be restored to the initial state, thereby avoiding the second use of the syringe.

Beneficial effect

Compared with the prior art, the above structure has the following beneficial effects:

(1) The structure is simple, the cost is low, the parts constituting the needle protection device are few, and the assembly is convenient;

(2) After the injection is completed, only need to push the sliding sleeve to the extended state, without additional rotation of the sliding sleeve and other actions, easy to operate, reliable to use, and avoid misoperation;

(3) The rod-shaped body of the non-return member has a convex edge, which makes the outer side surface of the rod-shaped body and the supporting member be linearly supported, so that the non-return member cannot be held on the outer side surface of the rod-shaped body as the supporting surface. The stable state makes the reliability of the non-return piece overturning under its own gravity better;

(4) The disc-shaped body of the non-return piece is an asymmetric structure relative to the reference plane where the rib is located, which further ensures the reliability of the non-return piece overturning under its own gravity;

(5) The sliding sleeve has a split structure, including a first sliding sleeve and a second sliding sleeve that are buckled with each other, which facilitates the assembly of the needle protection device;

(6) The function of setting two symmetrical accommodating planes on the plug body is that during the assembly process, the plug body has an additional assembly direction, which makes the assembly more efficient;

(7) The setting of the second initial limit mechanism helps reduce the risk of false triggering. At the same time, since the elastic limit member covers at least part of the accommodation space in the axial projection direction, it can prevent the sliding sleeve from reaching the extended state. The rod-shaped body enters the accommodating space again, and the reliability of limiting the recovery of the sliding sleeve is further enhanced.

Description of the drawings

Figure 1 is a schematic diagram of the structure of the safety syringe in this embodiment;

Fig. 2 is a schematic structural diagram of the safety syringe shown in Fig. 1 with a concealed needle protection device;

Figure 3 is a partial structural diagram of the safety syringe of this embodiment when the sliding sleeve is slid to an extended state;

Figure 4 is a partial structural diagram of the safety syringe of this embodiment after the sliding sleeve is slid to the extended state, after the non-return member is overturned;

Figure 5 is a rear view of the needle protection device in this embodiment;

Figure 6 is an A-A cross-sectional view of the needle protection device shown in Figure 5;

Figure 7 is a B-B cross-sectional view of the needle protection device shown in Figure 5;

Figure 8 is a left side view of the needle protection device shown in Figure 5;

Figure 9 is a C-C cross-sectional view of the needle protection device shown in Figure 8;

Figure 10 is a partial cross-sectional structural diagram of the needle protection device of this embodiment in the initial state;

Fig. 11 is a schematic partial cross-sectional view of the needle protection device shown in Fig. 10 from another angle;

Figure 12 is a schematic diagram of the structure of the plug body in this embodiment;

Fig. 13 is a schematic structural view of the plug body shown in Fig. 12 from another angle;

Figure 14 is a schematic diagram of the structure of the non-return member in this embodiment;

Fig. 15 is a schematic structural view of the non-return member shown in Fig. 14 from another angle;

Figure 16 is a side view of the non-return member shown in Figure 14;

Figure 17 is a schematic diagram of the combined position of the non-return member and the plug body in the initial state of this embodiment;

18 is a schematic diagram of the structure of the first sliding sleeve in this embodiment;

Figure 19 is a cross-sectional view of the first sliding sleeve shown in Figure 18;

20 is a schematic diagram of the internal structure of the first sliding sleeve shown in FIG. 18;

FIG. 21 is a schematic diagram of the structure of the second sliding sleeve in this embodiment.

The best mode of the present invention

Type here a paragraph describing the best mode of the present invention.

Embodiments of the present invention

In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not used to limit the present invention.

In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", "inner", "outer", etc. are based on the drawings shown The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the pointed device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention.

In the description of the present invention, it should be noted that the terms "installed", "connected", and "connected" should be understood in a broad sense unless otherwise clearly specified and limited. For example, they may be fixedly connected, integrally connected, or It can be a detachable connection; it can be the internal communication between two elements; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific conditions of the above-mentioned terms in the present invention can be understood. meaning.

In the needle protection device and the safety syringe containing the needle protection device in this embodiment, the end close to the patient is the front end, and the end far away from the patient is the back end.

The safety syringe of this embodiment, as shown in FIG. 1 and FIG. 2, includes a syringe 40, the front end of the syringe is provided with a needle seat 50, and an injection needle 60 is installed on the needle seat 50. Among them, the front end of the syringe is equipped with a needle protection device sheathed outside the needle seat and the injection needle. The function of the needle protection device is to prevent the injection needle from accidentally piercing the user after use and to prevent the secondary use of the safety syringe.

It should be noted that, in this embodiment, the needle seat and the needle cylinder are an integrated structure. Of course, the needle base and the syringe can also have a separate and detachable structure, and the syringes of these two structural forms are both existing mature technologies.

The needle protection device of this embodiment, as shown in FIGS. 4 to 11, includes a plug body 10, a non-return member 20 and a sliding sleeve 30.

The structure of the plug body 10 is shown in Figures 12 and 13, which is a cylindrical structure and is provided with an internal fixation cavity 11, which fits with the needle holder 50, and the plug body 10 passes through the inner fixation cavity 11. It is sleeved on the needle base 50, and the two are fixedly connected by conventional connection methods such as bonding and snapping.

In this embodiment, the outer wall of the plug body 10 is provided with an accommodating plane 12, the accommodating plane is provided with an elastic limiting member 13 at a position close to the front end, and the elastic limiting member 13 protrudes radially from the surface of the accommodating plane 12.

In this embodiment, the outer wall of the plug body 10 is also provided with guide grooves 14 axially penetrating the outer wall. The guide grooves 14 are usually provided with two and are evenly distributed along the circumferential direction of the plug body.

Furthermore, the outer wall of the plug body 10 of this embodiment is also provided with an initial limiting groove 15, and the rear end of the initial limiting groove 15 is an open end.

The non-return member 20 of this embodiment, as shown in Figs. 14-16, includes a disc-shaped body 21 and a rod-shaped body 22 connected to the edge of the disc-shaped body 21 and extending in the axial direction toward the rear side of the disc-shaped body. .

In this embodiment, the axial projected area of the disk-shaped body 21 is smaller than the axial projected area of the inner space of the sliding sleeve. In this way, the non-return member has enough space for free tilting in the inner space of the sliding sleeve.

Wherein, in the structure of the non-return member 20, the inner side surface of the rod-shaped body 22 is adapted to the accommodating plane 12, and the outer side surface of the rod-shaped body 22 is provided with an axially extending rib 26 and is configured as the rod-shaped body 22 The outer surface of the ridge extends from the rib 26 to the edge of the outer surface of the rod in a direction radially away from the inner surface of the sliding sleeve. When the outer side surface of the rod-shaped body 22 is supported on any supporting surface, since the rib 26 is in linear contact with the supporting surface, the non-return member will inevitably use the rib 26 as a linear support to randomly dump to both sides.

Preferably, in this embodiment, the rib 26 is arranged in the middle of the outer surface of the rod-shaped body 22, and the structure of the rod-shaped body is symmetrical with respect to the reference plane D where the rib 26 is located. The purpose of this arrangement is that when the rib is in contact with any supporting surface, the randomness of the non-return member falling to both sides is stronger.

In this embodiment, the disc 21 is provided with a via 25 through which the injection needle 60 passes, and the projected area of the via 25 is much larger than the cross-sectional area of the injection needle.

Preferably, in this embodiment, one side of the disc 21 is provided with a slot 27 that communicates with the via 25. The function of the slot 27 is that, during assembly, the injection needle must pass through the via. It can also be assembled from the side into the via hole from the side slot. The assembly method is more flexible and the assembly efficiency is higher. In addition, the arrangement of the slot 27 causes the two sides of the disc 21 to form an asymmetric structure with respect to the reference surface D. The asymmetric structure makes that when the rib contacts any supporting surface, due to the imbalance of gravity on both sides of the reference surface, The rate of dumping of the non-return piece is faster.

The sliding sleeve 30 of this embodiment is axially movably connected with the plug body, and the sliding sleeve has an initial state and an extended state in the axial direction. Preferably, the sliding sleeve 30 in this embodiment includes a first sliding sleeve 31 and a second sliding sleeve 32 that are buckled with each other.

Wherein, as shown in FIGS. 18-20, the outer circumference of the first sliding sleeve 31 is provided with an annular boss 313, which divides the first sliding sleeve 31 into a front sliding sleeve 312 and a rear sliding sleeve 311 . Wherein, as shown in FIG. 19, an annular cavity 316 is provided on the side of the annular boss 313 close to the front sliding sleeve 312. The annular cavity 316 is provided with an annular groove 317 at a position close to the bottom of the cavity. The diameter is larger than the outer diameter of the annular cavity 316.

In this embodiment, the inner wall of the first sliding sleeve 31 is provided with an accommodating groove 318 for accommodating the rod-shaped body 22. Wherein, as shown in FIG. 9, the accommodating groove 318 and the accommodating plane 12 on the plug body 10 form an accommodating space 70 for accommodating the rod-shaped body 22. In addition, the bottom of the receiving groove 318 is a stepped surface 319 that interacts with the free end of the rod-shaped body.

In this embodiment, the rear end of the first sliding sleeve 31 is provided with an inner flange 35. The inner diameter of the inner flange 35 is larger than the outer diameter of the barrel and smaller than the outer diameter of the plug body, so as to prevent the sliding sleeve from being axially connected to the plug body. Break away.

In this embodiment, an axial guide mechanism is provided between the first sliding sleeve 31 and the plug body 10. The function of the axial guide mechanism is to prevent the sliding sleeve from rotating relative to the plug body. Specifically, the axial guide mechanism includes a guide groove 14 provided on the plug body and a guide rib 34 provided on the inner wall of the first sliding sleeve. Of course, as an equivalent embodiment, the guide groove can also be provided on the inner wall of the first sliding sleeve, and correspondingly, the guide rib is provided on the outer wall of the plug body.

In this embodiment, as shown in FIG. 21, the rear end of the second sliding sleeve 32 is provided with an annular clamping edge 322 that is adapted to the annular clamping groove 317, and the annular clamping groove 317 is buckled with the annular clamping edge 322, As a result, the first sliding sleeve 31 and the second sliding sleeve 32 constitute an integral sliding sleeve 30.

In this embodiment, in order to facilitate the annular clamping edge to enter the annular cavity 316, the edge of the annular cavity is provided with a chamfer.

It should be noted that the buckling connection form of the annular groove 317 and the annular clamping edge 322 is only a preferred embodiment of this embodiment. As an equivalent embodiment, the mutual buckling groove and the clamping edge may be along the circumferential direction. Set up multiple groups.

In this embodiment, a front cover 321 is provided at the front end of the second sliding sleeve, and the front cover 321 is provided with a needle hole 323 for receiving the injection needle. Wherein, in this embodiment, the non-return member is located between the inner side of the front cover 321 and the plug body.

Preferably, in this embodiment, a first initial limit mechanism is provided between the first sliding sleeve 31 and the plug body 10, and the first initial limit mechanism is shown in Figure 7, Figure 12, Figure 13, Figure 19 and Figure 20 As shown, it includes an initial limiting groove 15 and a limiting protrusion 33 provided on the plug body. When it is necessary to push the sliding sleeve, it is necessary to apply a force sufficient to drive the limiting protrusion 33 to slide out of the initial limiting groove 15. Therefore, the function of the first initial limiting mechanism is to keep the sliding sleeve in the initial state. The existence of an initial limit mechanism can prevent the sliding sleeve from leaving the initial state due to misoperation.

Preferably, as shown in FIG. 13, a transition portion 17 is provided at the bottom edge of the initial limiting groove 15. The transition portion is an inclined surface or a curved surface, which can reduce the sliding of the limiting protrusion 33 out of the initial limiting groove 15 resistance.

A preferred embodiment. In this embodiment, the width of the rod-shaped body 22 is greater than the radial height where the ribs are located. The purpose of this arrangement is to strengthen the support strength of the non-return member. For a rectangle, when it overturns at a certain angle, it is difficult to enter the accommodating space again even if it receives an external force, thereby improving the reliability of the sliding sleeve in the extended state.

A preferred embodiment, in this embodiment, a second initial limit mechanism is provided between the non-return member 20 and the plug body 10, and the second initial limit mechanism is shown in Figure 6, Figure 13 and Figure 14. As shown, it includes an elastic limiting member 13 and a limiting groove 23 arranged on the inner side of the rod-shaped body at a position close to the disc-shaped body, and the elastic limiting member 13 and the limiting groove 23 are matedly connected.

In this embodiment, the elastic limiting member 13 covers at least a part of the containing space in the axial projection direction. The function of the second initial limit mechanism is to keep the non-return member and the sliding sleeve in the initial state. When pushing the sliding sleeve, it is necessary to overcome the resistance of the first initial limit mechanism and the second initial limit mechanism at the same time, which can prevent Misoperation. In addition, since the elastic limiting member 13 covers part of the accommodating space in the axial projection direction, when the sliding sleeve is pushed to the extended state, the rod-shaped body separates from the accommodating space. At this time, due to the random overturning of the non-return member, the rod-shaped The position of the body relative to the accommodating space changes, and it is difficult to change to a position where the rod-shaped body can enter the accommodating space again. Even if due to uncertainty, under the action of external force, the rod-shaped body just has a position where it can enter the containing space, because the elastic limiter covers the containing space, it will block the path of the rod-shaped body from entering the containing space, thus increasing One layer of protection further ensures that the sliding sleeve cannot be restored to the initial state again, and the reliability is stronger.

The needle protection device of this embodiment is assembled as follows: firstly, the first sliding sleeve is sleeved on the needle barrel. The entry method is that the rear end of the first sliding sleeve enters from one end of the injection needle, and then the plug body is bonded with The form of the first sliding sleeve is fixed on the plug body. Since the inner diameter of the inner flange at the rear end of the first sliding sleeve is smaller than the outer diameter of the plug body, the first sliding sleeve cannot escape from the plug body end. Then, the first sliding sleeve is moved to the position of the initial state, and the rod-shaped body of the non-return member is extended from the containing space. Finally, the second sliding sleeve and the first sliding sleeve are buckled together so that the first sliding sleeve and the second sliding sleeve form an integral structure of the sliding sleeve.

In the needle protection device and its safety syringe of this embodiment, in the initial state, as shown in Figs. In the containing space, the front cover of the sliding sleeve and the plug body are only separated by the thickness of the disc, and the axial distance is very small. This greatly reduces the ineffective length of the injection needle and effectively utilizes the sliding sleeve and the plug body. Between the axial space and the radial space.

After the injection is completed, the sliding sleeve can be pushed axially to the extended state. Under the action of the step surface, the rod-shaped body of the non-return member is pushed out of the accommodating space. The state is shown in Figure 3. In this state, there is no need Any operation, the non-return member will dump randomly, such as the state shown in Figure 4. After the non-return member is randomly dumped, it is supported between the front cover of the sliding sleeve and the front end of the plug body, which protects the injection needle while being effective Avoid secondary use.

The needle protection device and the safety syringe of this embodiment have the technical advantages of simple structure, low cost, convenient assembly, convenient operation, and safety and reliability.

In short, the above descriptions are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be included in the present invention. Within the scope of protection.

Industrial applicability

Type a paragraph describing industrial applicability here.

Sequence Listing Free Content

Type here the free content description paragraph of the sequence listing.

Claims

A needle protection device, characterized in that it at least comprises:

A plug body, the plug body is fixedly arranged;

A sliding sleeve, the sliding sleeve is sleeved outside the plug body and movably connected with the plug body in an axial direction, the sliding sleeve is configured to have an initial state and an extended state in the axial direction relative to the plug body; and

A non-return member, the non-return member includes a disc-shaped body and at least one rod-shaped body connected to the edge of the disc-shaped body and extending axially to one side of the disc-shaped body, the outer wall of the plug body and the sliding sleeve An accommodating space for accommodating the rod-shaped body is provided between the inner walls, and a step surface is arranged on the inner wall of the sliding sleeve and interacts with the free end of the rod-shaped body in the accommodating space, and the disc-shaped body is provided With a via hole, the axial projection of the disc-shaped body is smaller than the axial projection of the inner space of the sliding sleeve;

Wherein, the non-return member is configured such that: in the initial state of the sliding sleeve, the disc-shaped body is located between the end of the plug body and the end of the sliding sleeve, and the rod-shaped body is located in the accommodating space; In the extended state of the sleeve, the rod-shaped body is separated from the accommodating space, and the non-return member is supported between the end of the sliding sleeve and the end of the plug body.
The needle protection device according to claim 1, wherein the outer surface of the rod-shaped body is provided with an axially extending rib and is configured such that the outer surface of the rod-shaped body is radially away from the rib. The direction of the inner surface of the sliding sleeve extends to the edge of the outer side of the rod-shaped body.
The needle protection device according to claim 2, wherein the disc-shaped body has an asymmetric structure relative to the reference plane where the protruding ribs are located.
The needle protection device according to claim 1, wherein the sliding sleeve comprises a first sliding sleeve and a second sliding sleeve that are buckled with each other.
The needle protection device according to claim 1, wherein an axial guide mechanism and/or a first initial limit mechanism are provided between the sliding sleeve and the plug body.
The needle protection device according to claim 1, wherein the accommodating space at least comprises:

An accommodating groove provided on the inner wall of the sliding sleeve; and

The containing plane is arranged on the outer wall of the plug body and configured to fit the inner surface of the rod-shaped body.
The needle protection device according to claim 6, wherein the plug body is provided with two symmetrical receiving planes.
The needle protection device according to claim 1, wherein a second initial limit mechanism is provided between the non-return member and the plug body, and the second initial limit mechanism at least comprises:

An elastic limiting member, which is arranged at the end of the plug body and covers at least a part of the containing space in the axial projection direction; and

The limiting groove is arranged at a position where the inner side surface of the rod-shaped body is close to the disc-shaped body and is configured to fit with the elastic limiting member.
The needle protection device according to claim 8, wherein a guiding mechanism is provided between the elastic limiting member and the limiting groove, and the guiding structure includes a first guiding inclined surface provided on the elastic member and A second guiding inclined surface in the limiting groove and adapted to the first guiding inclined surface.
A safety syringe, characterized in that it at least includes:

A needle seat on which an injection needle is arranged; and

The needle protection device according to any one of claims 1-8, the plug body is fixedly connected to the needle seat, the injection needle passes through the through hole, and in the extended state of the sliding sleeve, The sliding sleeve covers the injection needle.