CN218636425U - Needle head protection type pre-filling and sealing syringe - Google Patents

Abstract

The utility model belongs to the technical field of embedment syringe in advance, especially, relate to syringe needle protection type embedment syringe in advance. The utility model discloses a cup joint the protection casing unit of the installed part of last needle at the injection cylinder, and fixed the elastic hook unit of protection casing unit has played the convenient technological effect that effectively covers to the syringe needle after the injection. The utility model has the advantages of it is following: firstly, the operation of opening injection and closing discarding can be realized only by sliding the protective cover along the injection needle cylinder when in use; secondly, an elastic hook is hooked with the side edge of the sliding opening and used for fixing the protective cover; thirdly, the elastic plate is clamped with the elastic hook, so that the protective cover can be fixed to be in an open state; fourthly, the elastic plate is pinched by a single hand, so that the protective cover can be ejected to the needle head to be closed; fifthly, when the needle protective sleeve coats the injection needle, the elastic plate and the elastic hook are disengaged, and the protective cover can be conveniently opened to directly inject.

Description

Needle head protection type pre-filling and sealing syringe

Technical Field

The utility model belongs to the technical field of embedment syringe in advance, especially, relate to syringe needle protection type embedment syringe in advance.

Background

A syringe is a common medical device, and is mainly used for extracting or injecting gas or liquid by using a needle, and the process is called injection, and the syringe consists of a syringe barrel with a small hole at the front end and a matched piston core rod and is used for injecting a small amount of liquid or gas into an area which cannot be accessed by other methods, and the liquid or gas is extruded when the core rod is pushed in. However, the stability of the disposable syringe is poor, the medicine needs to be filled before use, and the air needs to be extruded after the medicine is filled very inconveniently, so a medicine is filled in advance, the pre-filled syringe which is directly injected after being opened is developed and popularized for use, and nowadays, the pre-filled syringe is widely applied to vaccination during the epidemic situation of the novel coronavirus pneumonia, and the market value is very high.

However, the existing pre-filling and sealing syringe is often discarded at will after being used, the needle is exposed outside, the syringe is very dangerous, and the nurse often reloads the pulled needle protective sleeve back to solve the problem that the needle is exposed after the syringe is discarded. But do so and have a lot of shortcomings, on the one hand the syringe needle protective sheath is the syringe needle customization, and the opening is less, inserts again after pulling out hardly, and on the other hand the process of putting back again lets the syringe needle prick nurse's hand easily, causes medical personnel's infection, further causes the diffusion of epidemic situation to spread easily.

Therefore, in summary, there is an urgent need for a pre-filled and sealed syringe which can effectively cover the needle after injection and prevent the needle from hurting people.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a syringe needle protection formula embedment syringe in advance, the subassembly, the utility model discloses a cup joint the protection casing unit of the needle mounting part on the syringe needle cylinder, and fixed the elastic hook unit of protection casing unit has played the technical effect that effectively covers the syringe needle after the injection conveniently.

The utility model provides a technical scheme that above-mentioned problem adopted is: a needle head protection type pre-filling and sealing injector comprises an injection needle cylinder, a needle mounting piece, an injection needle and a needle protection sleeve; wherein:

the needle mounting piece is arranged at the far end of the injection needle cylinder, the needle mounting piece is provided with a through hole and is communicated with the interior of the injection needle cylinder, the injection needle is mounted on the needle mounting piece in a mode of being inserted into the through hole, the needle protective sleeve is sleeved on the needle mounting piece and completely covers the injection needle, and the injection needle cylinder, the needle mounting piece, the injection needle and the needle protective sleeve have a common axis;

still include the protection casing unit, the protection casing unit includes:

a protective cover with a sliding opening is arranged on the injection needle to shield the injection needle;

still include the elasticity hook unit, the elasticity hook unit is including setting up stretch into the elasticity hook of sliding opening.

The protection casing unit still includes the elastic plate, the elastic plate cantilever sets up in the sliding port, the near-end has along the radial adduction trend of protection casing.

The near end of the elastic plate is provided with a near end stop surface for jacking the elastic hook when the protective cover is closed so as to lock the protective cover.

The inner side of the elastic plate is provided with a far-end stop surface used for jacking the elastic hook when the protective cover is opened, so that the protective cover is locked.

The elastic hook comprises a radial plate, and a stop surface for closing is arranged on the far end side of the radial plate and used for jacking the near-end stop surface.

The elastic hook further comprises an axial plate, and an opening stop surface is arranged on the near end side of the axial plate and used for jacking the far end stop surface.

The axial plate near-end is followed the radial outside expansion of protection casing jacks up when the distal end is stopped the position face, through following the protection casing is radial inwards pressed or is outwards pulled the elastic plate makes the opening of axial plate with the distal end is stopped the position face and is broken away from the jack-up state.

The needle protection sleeve is sleeved on the needle mounting piece, and the protection cover radially jacks outwards to enable the near-end stop face on the elastic plate to be in a state of releasing jacking with the stop face on the radial plate.

The proximal side of the protruding block is provided with an opening guide surface, and the protective cover is used for jacking up the axial plate of the elastic hook when sliding towards the proximal end, so that the elastic hook passes over the protruding block.

The projection block further includes a closing guide surface for lifting an axial plate of the elastic hook when the shield is slid distally so that the elastic hook passes over the projection block.

The shield unit further comprises an expansion groove provided at the proximal end of the shield for expansion of the proximal end of the shield.

The protection cover unit further comprises a guide inclined plane arranged at the near end of the protection cover and used for jacking up the axial plate of the elastic hook.

The needle head protection type pre-filling and sealing syringe assembly comprises a push rod and a piston; wherein:

the push rod is arranged on the piston;

the piston is arranged in the injection syringe and is used for pushing out the liquid medicine through the injection needle when pushing the push rod towards the far end direction.

A method of installing an assembly of a needle-shielded pre-filled syringe, comprising the steps of:

s1, axially installing the needle protection sleeve into the protection cover;

s2, sleeving the protective cover with the needle protective sleeve on the needle mounting piece along the axial direction;

s3, pushing the piston into the injection needle cylinder;

s4, arranging the push rod on the piston.

A method of using an assembly of a needle-protected prefilled syringe, comprising the steps of:

s1, axially moving the protective cover along the proximal direction of the injection needle cylinder until one side of the back surface of the hook of the elastic hook props against the distal side surface of the sliding port, so that the needle protective sleeve is exposed;

s2, opening the needle protective sleeve to expose the injection needle;

s3, performing injection operation;

and S4, after the injection operation is finished, axially moving the protective cover along the far end direction of the injection needle cylinder until one side of the hook of the elastic hook hooks the side surface of the near end of the sliding port, so that the injection needle is completely covered.

The utility model has the advantages of it is following:

firstly, the mounting is convenient, the structure is simple, and the operation of opening the injection and closing the discard can be realized only by sliding the protective cover along the injection needle cylinder when in use;

secondly, the elastic hook is hooked with the side edge of the sliding opening and used for fixing the protective cover, the fixing effect is good, and the protective cover is not easy to be separated from a clamping state;

thirdly, the elastic plate is arranged, the stop surface is arranged on the elastic plate and is clamped with the elastic hook, so that the protective cover can be fixed to be in an open state, and the injection is convenient for nurses to inject;

fourthly, after the nurse finishes the injection, the stop surface and the elastic hook can be disengaged by pinching the elastic plate with the two fingers, so that the protective cover is ejected to the needle head to be closed, and the nurse can operate the protective cover with one hand by pinching the protective cover to close the protective cover with short fingers;

fifthly, when the needle protective cover covers the injection needle, the elastic plate and the elastic hook are released from the clamping state, and a nurse can conveniently open the protective cover to directly inject.

Drawings

Fig. 1 is the structure schematic diagram of the needle protecting sleeve cladding injection needle of the utility model, and the protecting cover unit and the elastic hook unit are installed on the injection needle cylinder.

Fig. 2 is the structure diagram of the needle protecting sleeve coated injection needle of the present invention, and the injection needle cylinder is provided with the elastic hook unit.

Fig. 3 is a schematic structural view of the injection needle cylinder of the present invention with an elastic hook unit installed thereon.

Fig. 4 is a schematic structural view of the protective cover unit and the elastic hook unit mounted on the middle syringe of the present invention.

Fig. 5 is the explosion schematic diagram of the middle pre-filled and sealed injector of the present invention.

Fig. 6 isbase:Sub>A schematic cross-sectional view taken along linebase:Sub>A-base:Sub>A in fig. 4.

Fig. 7 is an enlarged schematic view of the elastic hook of fig. 6.

Fig. 8 is an enlarged view of the injection needle of fig. 6.

Fig. 9 is a schematic structural view of the elastic hook of the present invention.

Fig. 10 is a schematic structural view of the other side of the elastic hook according to the present invention.

Fig. 11 is a schematic structural diagram of the middle protective cover unit of the present invention.

Fig. 12 is a schematic structural view of the other side view of the middle protective cover unit of the present invention.

Fig. 13 is a schematic structural view of the middle elastic plate of the present invention.

In the drawings, the reference numerals denote the following components: the safety guard unit 1, the elastic hook unit 2, the syringe 11, the needle mount 12, the injection needle 13, the needle protection cover 14, the safety guard 101, the sliding port 102, the elastic plate 103, the expansion groove 104, the guide slope 105, the elastic hook 202, the proximal end stop surface 103a, the distal end stop surface 103b, the protrusion 103c, the opening guide surface 103d, the closing guide surface 103e, the stop groove 201a, the radial plate 202a, the axial plate 202b, the closing stop surface 202c, the opening stop surface 202d, and the through hole 12a.

Detailed Description

Definition of

1. A far end: refers to the end far away from the medicine injection opening of the injection syringe.

2. Near end: refers to the end facing the medicine injection port of the injection syringe.

3. Axis: refers to an object having a circular cross-section through the vertical line of the center of the circle.

4. Opening: refers to a state in which the syringe needle or the syringe needle and the protective sheath are exposed.

5. Closing: the finger is in a state of covering the syringe needle or the syringe needle and the protective sleeve.

6. Setting: refers to any means for arranging and bonding two components together by adhesive, snap-fit, welding, screwing, placing, etc.

7. Jacking: the first finger component exerts a force on the second finger component, so that the second finger component moves or deforms towards the direction opposite to the position of the first finger component.

The following description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Example (b): as shown in fig. 1-13, a needle-protected prefilled syringe includes a syringe barrel 11, a needle mounting member 12, a needle 13 and a needle protection cover 14; wherein:

the needle mounting member 12 is disposed at the distal end of the syringe 11, the needle mounting member 12 has a through hole 12a communicating with the inside of the syringe 11, the injection needle 13 is mounted on the needle mounting member 12 in such a manner as to be inserted into the through hole 12a, the needle protection cover 14 is fitted over the needle mounting member 12 and completely covers the injection needle 13, and the syringe 11, the needle mounting member 12, the injection needle 13, and the needle protection cover 14 have a common axis;

still include protection casing unit 1, protection casing unit 1 includes:

a shield 101 provided with a sliding port 102 to shield the injection needle 13;

the device also comprises an elastic hook unit 2, wherein the elastic hook unit 2 comprises an elastic hook 202 which is arranged on the sliding opening 102.

In this embodiment, the injection syringe 11, the needle mounting member 12, the injection needle 13 and the needle protecting cover 14 are all necessary components of an injector in the prior art to achieve the functions of filling and injecting the medicine, and the elastic hook unit 2 and the protecting cover unit 1 are installed in the following manner:

1. the elastic hook unit 2 is mounted on the needle mount 12 with the hook bent toward the proximal end of the syringe barrel 11;

2. when the protective cover 101 of the protective cover unit 1 is mounted on the needle mounting member 12 in a sleeved manner, the protective cover is mounted on the elastic hook 202 of the elastic hook unit 2 in a sleeved manner through deformation, and after the protective cover passes over the elastic hook 202, the sliding opening 102 is sleeved on the elastic hook 202.

The elastic hook 202 slides into the sliding opening 102 in the sleeving process and hooks the side surface of one side of the proximal end of the sliding opening 102, so that the blocking effect of the sliding of the protective cover 101 towards the distal end direction is realized.

After the installation is finished, the components are handed over to downstream manufacturers to fill the medicines, the medicines are filled from the medicine injection opening of the injection needle cylinder 11, and then a push rod and an injection piston are installed on the injection needle cylinder 11 through the medicine injection opening to complete the pre-encapsulation of the injector.

Furthermore, it should be noted that the needle protection sheath 14 is standardized in shape using existing pre-potted needle sheath materials, rather than a non-standard shaped cap, which is advantageous in that:

1. the use habit of the user is not changed;

2. the chemical compatibility of the rubber protective cap does not need to be evaluated again, and the project development period and the product registration period are greatly reduced;

3. enhancing the customer confidence.

The using method of the pre-filled and sealed syringe comprises the following steps:

1. axially moving the protective cover 101 in the proximal direction of the syringe 11 until the hook back side of the elastic hook 202 abuts against the distal side of the sliding port 102, thereby exposing the needle protecting cover 14;

2. opening the needle protection 14 to expose the injection needle 13;

3. carrying out injection operation;

4. after the injection operation is completed, the protective cover 101 is axially moved along the distal direction of the syringe 11 until the hook side of the elastic hook 202 catches the proximal side surface of the sliding port 102, so as to completely cover the injection needle 13.

The mounting method of the pre-filled and sealed syringe comprises the following steps:

s1, axially installing the needle protection sleeve 14 into the protection cover 101;

s2, the protective cover 101 with the needle protective sleeve 14 is sleeved on the needle mounting piece 12 along the axial direction;

s3, pushing the piston into the injection needle cylinder 11;

and S4, arranging the push rod on the piston.

In this embodiment, the needle protection sleeve 14 is first installed in the protection cover 101, which is beneficial to the steps of automatic assembly of syringe components, and can simplify the flow of production line, reduce the cost of component installation process, and further improve market competitiveness.

It should be noted that the position of the elastic hook 202 may be a part of the syringe 11, a part of the needle mount 12, or a part between the syringe 11 and the needle mount 12.

In addition, can carry out the light inspection to the syringe when the syringe leaves the factory, the "light inspection" sees through the cylinder and passes through the manual observation mode in order to inspect whether qualified in syringe filling plus stopper, and most integral type safety covers in the market then can influence this process, and china utility model that bulletin number is CN214911888U, bulletin day is 2021-11-30 for example discloses a syringe needle protection device and safety syringe, including the protective sheath, installation endotheca, spring, this kind of inner and outer cover ways has blockked the inside field of vision of cylinder, influences the light and examines the process, and in this embodiment, protective sheath unit 2 has only covered needle installation pipe 12 under the syringe not in-use condition to and the process that the light was examined can not influenced to some distal end of cylinder 11.

However, the protection cover 101 needs to achieve a fixing effect after being closed, and further, the protection cover unit 1 further comprises an elastic plate 103, the elastic plate 103 is cantilevered in the sliding opening 102, and the proximal end has a tendency to retract along the radial direction of the protection cover 101.

The function and implementation of the elastic plate 103 are as follows:

1. when the protective cover 101 is opened, the elastic hook 202 jacks up the elastic plate 103 along the radial direction of the protective cover 101 outwards, so that elastic potential energy is accumulated in the elastic plate 103, and when the protective cover 101 is released, the elastic potential energy of the elastic plate 103 is released to drive the protective cover 101 to be ejected out axially along the distal direction of the injection syringe 11, so that the automatic closing effect is realized;

2. when the protection cover 101 is closed, the proximal end surface of the elastic plate 103 pushes up the hook back surface of the elastic hook 202, so that the protection cover 101 is pushed against the hook back surface of the elastic hook 202 when moving towards the proximal end, and the elastic hook 202 hooks the inner side surface of the sliding opening 102 when moving towards the distal end, thereby achieving a locking effect.

In order to make the elastic plate 103 lock the elastic hook 202 more firmly, further, the elastic plate 103 has a proximal end stop surface 103a at a proximal end thereof for lifting up the elastic hook 202 when the protection cover 101 is closed, thereby locking the protection cover 101.

When the protection shield 101 is opened, it is still necessary for the nurse to pull it by hand, which is inconvenient for the injection process, and further, the elastic plate 103 is provided at an inner side thereof with a distal end stop surface 103b for lifting up the elastic hook 202 when the protection shield 101 is opened, thereby locking the protection shield 101.

When the elastic hook 202 pushes up the elastic plate 103 radially outward along the protection cover 101, according to the principle of interaction of force, the elastic plate 103 also pushes up the elastic hook 202 radially inward along the protection cover 101, so that the elastic hook 202 contracts, and when passing over the distal end stop surface 103b, the elastic hook 202 rebounds to return to its original shape, and then hooks the distal end stop surface 103b, so that the protection cover 101 cannot slide in the distal direction even under the pushing action of the elastic plate 103.

In addition, when the elastic hook 202 hooks the distal stop surface 103b, a "snap" sound is generated to alert the nurse that the shield 101 is locked and an injection is available.

In order to match the proximal end stop surface 103a, further, the elastic hook 202 includes a radial plate 202a, and a closing stop surface 202c for jacking up the proximal end stop surface 103a is provided on a distal end side of the radial plate 202 a.

When the closing stop surface 202c pushes up on the proximal stop surface 103a, a "snap" sound is also produced alerting the nurse that the shield 101 is locked and may be discarded.

Meanwhile, in order to match the distal end stop surface 103b, further, the elastic hook 202 further includes an axial plate 202b, and an opening stop surface 202d is provided on a proximal end side of the axial plate 202b, and is used for jacking up the distal end stop surface 103b.

After the injection is completed, the protection cover 101 needs to be closed, and in order to make the closing process smoother, further, the proximal end of the axial plate 202b expands radially outward along the protection cover 101, and when the distal end stop surface 103b is jacked up, the elastic plate 103 is pressed or pulled radially inward along the protection cover 101, so that the open stop surface 202d of the axial plate 202b and the distal end stop surface 103b are separated from the jacking state.

When the elastic plate 103 is pulled radially outward, the distal end stop surface 103b is moved radially outward, and is thereby disengaged from the open stop surface 202d of the axial plate 202b in the lifted state.

The principle of pressing the elastic plate 103 radially inward to separate the opening stop surface 202d of the axial plate 202b from the distal end stop surface 103b in the above-described process is as follows:

when the elastic plate 103 is expanded by a force, the proximal end is expanded to a greater extent than the distal end, the inner side surface of the elastic plate 103 inclines outward from the distal end to the proximal end, the axial plate 202b inclines in a manner consistent with the inner side surface of the elastic plate 103, so that when the elastic plate 103 is pressed radially inward along the shield 101, because the elastic plate 103 has a longer length, the axial plate 202b has a shorter length, and when the same distance is pressed, the axial plate 202b contracts more significantly, so that when the elastic plate is pressed to a certain extent, the opening stopper surface 202d of the axial plate 202b is disengaged from the distal stopper surface 103b, and the shield 101 is closed under the urging action of the elastic plate 103.

The advantage of this kind of design lies in, the nurse finishes injecting the back, as long as uses two fingers of thumb and forefinger, holds between the fingers gently, just can realize closing protection casing 101, compare the mode that promotes to close, holds between the fingers the mode of closing like this, need not nurse's palm application of force, also need not to remove thumb and forefinger and keep away from the palm, to the nurse that the finger is shorter little, also can realize single-handed operation, be one kind promptly for ingenious design. Meanwhile, the inward pinching mode is more convenient than outward poking, the angle does not need to be found, the fingernail does not need to be embedded into the sliding opening 102, and even the operation can be realized without visual observation of a nurse.

In order to make it unnecessary to lift the elastic plate 103 when the protective cover 101 is opened, a raised piece 103c is further provided on an inner side surface of a proximal end side of the elastic plate 103, and when the needle protective cover 14 is fitted to the needle mount 12, the raised piece 103c is raised radially outward along the protective cover 101, so that the raised state is released between the proximal end stop surface 103a on the elastic plate 103 and the stop surface 202c for closing on the radial plate 202 a.

In order that the projection 103c does not interfere with the opening process of the shield 101, further, the proximal side of the projection 103c has an opening guide surface 103d for lifting up the axial plate 202b of the elastic hook 202 when the shield 101 is slid proximally, thereby allowing the elastic hook 202 to pass over the projection 103c.

In order that the projection 103c does not interfere with the closing process of the protection cover 101, further, the projection 103c further includes a closing guide surface 103e for lifting up the axial plate 202b of the elastic hook 202 when the protection cover 101 is slid distally, so that the elastic hook 202 passes over the projection 103c.

The protection casing 101 cup joints when installing on the needle installed part 12, cup joints simultaneously through the deformation effect on the elastic hook 202, but protection casing 101 has certain thickness, is difficult to the deformation, and the installation is more laboursome, and is further, protection casing unit 1 still including setting up the expansion of protection casing 101 near-end is with groove 104, be used for the near-end expansion of protection casing 101.

When the protection cover 101 is deformed after the expansion groove 104 is provided, the protection cover 101 can be given a space to move so as to easily pass over the elastic hook 202 by expanding the expansion groove 104.

In order to make the process of the protection shield 101 passing over the elastic hook 202 smoother, further, the protection shield unit 1 further includes a guide slope 105 provided at the proximal end of the protection shield 101 for jacking up the axial plate 202b of the elastic hook 202.

The inclined angle of the guiding bevel 105 is similar to the axial plate 202b, and when the axial plate 202b is lifted, the proximal end of the protection cover 101 is driven to expand so as to get over the elastic hook 202.

An assembly of the needle-protected pre-filled syringe includes a push rod and a piston; wherein:

the push rod is arranged on the piston;

the plunger is installed in the syringe 11 and pushes the plunger in a distal direction to push out the medical solution through the needle 13.

In the present embodiment, the key point is that the push rod and the piston are detachably connected together, so that the piston is easily installed in the syringe 11 in a mechanical and automatic manner, and the push rod and piston assembly method and the medicine filling method are as follows:

s1, syringe placement: grabbing the injector body, and enabling the injection needle cylinder 11 to be in a state of being vertical to a horizontal plane, wherein the opening of the near end is upward;

in the present embodiment, the step of "grabbing" generally employs a mechanical arm designed by a program, and the core of the program is to keep the syringe 11 in a vertical state when reaching the position to be filled, so that the liquid level after filling medicine is axially vertical to the syringe 11, so as to leave no air or less air after packaging but not affect the injection process.

S2, filling the medicine: filling the syringe 11 with a specified medicine;

in this embodiment, the "designated drug" refers to a drug that is self-filled according to the customer's requirement, for example, a manufacturer that fills a new coronavirus vaccine, and the designated drug is an inactivated new coronavirus.

S3, sleeve plugging: inserting the sleeve with the piston into the injection needle cylinder 11, wherein a gap is reserved between the outer annular surface of the sleeve and the inner annular surface of the injection needle cylinder 11, and then pushing the piston into the injection needle cylinder 11 along the inner annular surface of the sleeve by using a sleeve push rod;

in this embodiment, the plunger is a device for pushing medicine, which is commonly used in an injector, and is generally made of medical rubber, and is compressed in the sleeve and expanded to fit the inner side of the syringe barrel 11 after leaving the sleeve.

Furthermore, the sleeve is an elongated steel tube and is inserted into the syringe barrel 11 from the crimp and the plunger is moved by means of a sleeve pusher mounted in the sleeve to a predetermined position, which is after the plunger has left the sleeve, just above the surface of the medical fluid, leaving no or little air between them and not affecting the injection process.

S4, installing a push rod: the push rod is inserted into the syringe 11 and mounted on the piston, completing the potting process.

In this embodiment, a mounting groove for mounting the push rod is reserved at the proximal end of the piston, and the push rod is rotatably inserted into the mounting groove by using a mechanical arm.

S5, performing light inspection and labeling on the filled injector, and finally completing packaging.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art. These are non-inventive modifications, which are intended to be protected by patent laws within the scope of the appended claims.

Claims (12)

1. A needle-protected prefilled syringe comprises a syringe barrel (11), a needle mounting member (12), a syringe needle (13) and a needle protection sleeve (14); wherein:

the needle mounting piece (12) is arranged at the far end of the injection needle cylinder (11), the needle mounting piece (12) is provided with a through hole (12 a) which is communicated with the inside of the injection needle cylinder (11), the injection needle (13) is arranged on the needle mounting piece (12) in a mode of being inserted into the through hole (12 a), the needle protecting sleeve (14) is sleeved on the needle mounting piece (12) and completely covers the injection needle (13), and the injection needle cylinder (11), the needle mounting piece (12), the injection needle (13) and the needle protecting sleeve (14) have a common axis;

characterized in that, still include protection casing unit (1), protection casing unit (1) includes:

a protective cover (101) provided with a sliding opening (102) to shield the injection needle (13);

the sliding device further comprises an elastic hook unit (2), wherein the elastic hook unit (2) comprises an elastic hook (202) extending into the sliding opening (102).

2. A needle-shielded pre-filled and sealed syringe according to claim 1, characterized in that said shield unit (1) further comprises a resilient plate (103), said resilient plate (103) being cantilevered inside said sliding port (102), the proximal end having a tendency to retract radially inwards of said shield (101).

3. A needle-shielded pre-filled and sealed syringe according to claim 2, characterized in that the proximal end of the elastic plate (103) has a proximal stop surface (103 a) for lifting the elastic hook (202) when the shield (101) is closed, thereby locking the shield (101).

4. A needle-protected pre-filled and sealed syringe according to claim 3, characterised in that the elastic plate (103) is provided inside with a distal stop surface (103 b) for lifting the elastic hook (202) when the shield (101) is opened, thereby locking the shield (101).

5. A needle-protected pre-filled and sealed syringe according to claim 4, characterised in that said elastic hook (202) comprises a radial plate (202 a), said radial plate (202 a) being provided with a closing stop surface (202 c) at its distal side for jacking up said proximal stop surface (103 a).

6. A needle-shielded pre-filled and sealed syringe according to claim 5, characterized in that the elastic hook (202) further comprises an axial plate (202 b), and the proximal side of the axial plate (202 b) is provided with an opening stop surface (202 d) for jacking up the distal stop surface (103 b).

7. A needle-shielded pre-filled and sealed syringe according to claim 6, characterized in that the proximal end of the axial plate (202 b) is expanded radially outwards along the shield (101) and the distal stop surface (103 b) is lifted up by pressing or pulling the resilient plate (103) radially inwards along the shield (101) to disengage the opening stop surface (202 d) of the axial plate (202 b) from the distal stop surface (103 b) in the lifted-up state.

8. A needle-protected prefilled syringe according to claim 5, wherein said resilient plate (103) is provided with a protrusion (103 c) on the inner side of the proximal side, and said needle protective sheath (14) is attached to said needle mount (12) to radially lift said protrusion (103 c) outwards along said shield (101) so that said proximal stop surface (103 a) on said resilient plate (103) is released from said lifting state with said closing stop surface (202 c) on said radial plate (202 a).

9. A needle-shielded pre-filled and sealed syringe according to claim 8, characterized in that the proximal side of the boss (103 c) has an opening guide surface (103 d) for lifting up the axial plate (202 b) of the elastic hook (202) when the shield (101) is slid proximally, so that the elastic hook (202) passes over the boss (103 c).

10. A needle-shielded pre-filled and sealed syringe according to claim 9, characterized in that said protruding block (103 c) further comprises a closing guide surface (103 e) for lifting up the axial plate (202 b) of said elastic hook (202) when said protection shield (101) is slid distally, so that said elastic hook (202) passes over said protruding block (103 c).

11. A needle-protected pre-filled and sealed syringe according to claim 1, characterised in that said shield unit (1) further comprises an expansion groove (104) provided at the proximal end of said shield (101) for the proximal expansion of said shield (101).

12. A needle-shielded pre-filled and sealed syringe according to claim 6, characterized in that said shield unit (1) further comprises a guide bevel (105) provided at the proximal end of said shield (101) for jacking up the axial plate (202 b) of said elastic hook (202).

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