CN111529825B

CN111529825B - Needle head protection device and safety syringe

Info

Publication number: CN111529825B
Application number: CN202010439206.XA
Authority: CN
Inventors: 胡超宇
Original assignee: Pu'ang Hangzhou Medical Technology Co ltd
Current assignee: Puang (Hangzhou) Medical Technology Co.,Ltd.
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2020-12-15
Anticipated expiration: 2040-05-22
Also published as: WO2021233201A1; CN111529825A

Abstract

The invention relates to the technical field of medical syringes, and particularly discloses a needle head protection device and a safety syringe, wherein the needle head protection device at least comprises a plug body, a sliding sleeve and a check piece, the sliding sleeve is sleeved outside the plug body and is axially and movably connected with the plug body, the sliding sleeve is configured to have an initial state and an extending state along the axial direction relative to the plug body, and the check piece is configured to: in the initial state of the sliding sleeve, the disc-shaped body is positioned between the end part of the plug body and the end part of the sliding sleeve, and the rod-shaped body is positioned in the accommodating space; in the extending state of the sliding sleeve, the rod-shaped body is separated from the accommodating space, and the check piece is supported between the end part of the sliding sleeve and the end part of the plug body. The needle head protection device and the safety syringe with the structure have the technical advantages of simple structure, low cost, convenience in assembly, convenience in operation, safety and reliability.

Description

Needle head protection device and safety syringe

Technical Field

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

Background

Disposable safety syringe is common medical instrument, in order to prevent syringe needle accidental injury user after the use and prevent syringe secondary use, this type of syringe is provided with needle protection device usually, covers the needle after using in order to prevent that the needle from accidental injury user, and this needle protection device still has the non return structure simultaneously to prevent that needle protection device from recovering to initial position again after covering the needle, thereby solve and prevent the problem of secondary use.

In the prior art, one type is a needle retraction type safety syringe, which has a complicated structure and high cost.

In addition, there is a sliding sleeve type safety syringe in the prior art, for example, the chinese utility model with the publication number CN203043181U discloses a sliding sleeve type needle protection device and a safety syringe. Compared with an automatic retraction type injector, the injector with the structure has the advantages of simpler structure and lower cost. In the structure, after injection is finished, the sliding sleeve is firstly pushed to cover the needle head, and then the sliding sleeve is required to be rotated to lock the sliding sleeve. The disadvantage of this sliding sleeve type safety syringe is that:

(1) the operation is complex, the action of rotating the sliding sleeve is needed after pushing the sliding sleeve, and a larger force is needed to be applied when the sliding sleeve is rotated, so that the locking function of the locking mechanism can be realized;

(2) the sliding sleeve is unidirectional when rotated, the locking mechanism cannot be triggered if the sliding sleeve is rotated in the opposite direction, in actual operation, a user cannot remember the rotating direction at all times, and the needle head protection device can be damaged directly when the user mistakenly operates the sliding sleeve rotated in the opposite direction based on basic knowledge that the user needs to apply a large force to rotate and lock the sliding sleeve.

Disclosure of Invention

The invention aims to provide a needle head protection device with an improved structure and a safety syringe, so as to solve the defects of the prior art.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: a needle protection device comprising at least:

the plug body is fixedly arranged;

the sliding sleeve is sleeved outside the plug body and is axially and movably connected with the plug body, and the sliding sleeve is configured to have an initial state and an extending state relative to the plug body along the axial direction; and

the check piece comprises a disc-shaped body and at least one rod-shaped body which is connected with the edge of the disc-shaped body and extends axially to one side of the disc-shaped body, an accommodating space for accommodating the rod-shaped body is arranged between the outer wall of the plug body and the inner wall of the sliding sleeve, a step surface which is configured on the inner wall of the sliding sleeve and interacts with the free end of the rod-shaped body is arranged in the accommodating space, a through hole is formed in the disc-shaped body, and the axial projection area of the disc-shaped body is smaller than that of the inner space of the sliding sleeve;

wherein the check is configured to: in the initial state of the sliding sleeve, the disc-shaped body is positioned between the end part of the plug body and the end part of the sliding sleeve, and the rod-shaped body is positioned in the accommodating space; in the extending state of the sliding sleeve, the rod-shaped body is separated from the accommodating space, and the check piece is supported between the end part of the sliding sleeve and the end part of the plug body.

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

In a preferred embodiment, the disc-shaped body is asymmetric with respect to a reference plane on which the rib is located.

In a preferred embodiment, the sliding sleeves comprise a first sliding sleeve and a second sliding sleeve which are buckled with each other.

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

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

the accommodating groove is formed in the inner wall of the sliding sleeve; and

and the accommodating plane is arranged on the outer wall of the plug body and is configured to be matched with the inner side surface of the rod-shaped body.

In a preferred embodiment, the plug body is provided with two mutually symmetrical receiving planes.

In a preferred embodiment, a second initial limiting mechanism is disposed between the check piece and the plug body, and the second initial limiting mechanism at least includes:

the elastic limiting piece is arranged at the end part of the plug body and at least covers a part of the accommodating space in the axial projection direction; and

the limiting groove is arranged at the position, close to the disc-shaped body, of the inner side face of the rod-shaped body and is configured to be matched with the elastic limiting piece.

In a preferred embodiment, a guiding mechanism is disposed between the elastic limiting member and the limiting groove, and the guiding mechanism includes a first guiding inclined surface disposed on the elastic member and a second guiding inclined surface disposed in the limiting groove and adapted to the first guiding inclined surface.

A safety syringe comprising at least:

the needle seat is provided with an injection needle; and

the syringe needle protection device, cock body fixed connection in on the needle file, the syringe needle passes the via hole the state of stretching out of sliding sleeve, the sliding sleeve covers the syringe needle.

According to the needle head protection device and the safety syringe comprising the needle head protection device, when the sliding sleeve is in the extending state and the rod-shaped body is separated from the accommodating space, the axial projection area of the disk-shaped body in the check piece is smaller than that of the inner space of the sliding sleeve, the check piece randomly overturns under the action of self gravity, so that the check piece is supported between the end part of the sliding sleeve and the end part of the plug body, and the sliding sleeve is kept in the extending state and cannot be restored to the initial state while the needle head is protected to prevent accidental puncture, so that the secondary use of the syringe is avoided.

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

(1) the structure is simple, the cost is low, the number of parts for forming the needle head protection device is small, and the assembly is convenient;

(2) after injection is finished, the sliding sleeve is pushed to the extending state, extra actions such as rotating the sliding sleeve are not needed, the operation is convenient, the use is reliable, and the condition of misoperation is avoided;

(3) the rod-shaped body of the check piece is provided with the convex edge, and the convex edge enables the outer side surface of the rod-shaped body and the supporting part to be linearly supported, so that the check piece cannot be kept in a stable state by taking the outer side surface of the rod-shaped body as a supporting surface, and the reliability of the check piece in overturning under the self gravity is better;

(4) the disc-shaped body of the check piece is in an asymmetric structure relative to the reference plane where the convex edge is located, so that the reliability of the overturn of the check piece under the self gravity is further ensured;

(5) the sliding sleeve is of a split structure and comprises a first sliding sleeve and a second sliding sleeve which are mutually buckled, so that the assembly of the needle head protection device is facilitated;

(6) the plug body is provided with the two mutually symmetrical containing planes, so that the plug body has one more assembling direction in the assembling process, and the assembling efficiency is higher;

(7) the setting of the initial stop gear of second helps reducing the risk of false triggering, simultaneously, because the elastic limiting part covers part accommodation space at least in the axial projection direction, after the sliding sleeve reaches the state of stretching out, can prevent that the rod-shaped body from getting into accommodation space again, and the reliability of restriction sliding sleeve recovery obtains further reinforcing.

Drawings

FIG. 1 is a schematic view of the safety syringe of the present embodiment;

FIG. 2 is a schematic view of the safety syringe of FIG. 1 showing a hidden needle guard;

FIG. 3 is a schematic view of a partial structure of the safety syringe of this embodiment when the sliding sleeve slides to an extended state;

FIG. 4 is a schematic view of a part of the safety syringe of this embodiment after the sliding sleeve slides to an extended state and the check member is overturned;

FIG. 5 is a rear view of the needle guard of this embodiment;

FIG. 6 is a cross-sectional view A-A of the needle guard of FIG. 5;

FIG. 7 is a cross-sectional view B-B of the needle guard of FIG. 5;

FIG. 8 is a left side elevational view of the needle guard illustrated in FIG. 5;

fig. 9 is a cross-sectional view C-C of the needle guard of fig. 8;

FIG. 10 is a partial sectional view of the needle guard of this embodiment in an initial state;

FIG. 11 is a schematic view, partly in section, of the needle guard of FIG. 10 at another angle;

FIG. 12 is a schematic structural view of the plug body in the present embodiment;

FIG. 13 is a schematic view of the plug body of FIG. 12 at another angle;

FIG. 14 is a schematic view of the structure of the stopping element of the present embodiment;

FIG. 15 is a schematic view of the check of FIG. 14 at another angle;

FIG. 16 is a side view of the check of FIG. 14;

FIG. 17 is a schematic view of the combined position of the check member and the plug body of the present embodiment in the initial state;

FIG. 18 is a schematic structural view of the first sliding sleeve of the present embodiment;

figure 19 is a cross-sectional view of the first runner of figure 18;

FIG. 20 is a schematic view of the internal construction of the first runner of FIG. 18;

FIG. 21 is a schematic structural view of the second sliding sleeve in this embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as being fixedly connected, integrally connected, or detachably connected; may be communication within two elements; they may be directly connected or indirectly connected through an intermediate, and those skilled in the art will understand the specific meaning of the above terms in the present invention in specific situations.

In the needle protector and the safety syringe including the needle protector in this embodiment, the end close to the patient is the front end, and the end far from the patient is the rear end.

The safety syringe of the present embodiment, as shown in fig. 1 and 2, includes a cylinder 40, a needle holder 50 is provided at the front end of the cylinder, and an injection needle 60 is mounted on the needle holder 50. The front end of the syringe is provided with a needle head protection device sleeved outside the needle seat and the injection needle, and the needle head protection device has the functions of preventing the injection needle after use from accidentally stabbing users and preventing the safe injector from being used for the second time.

It should be noted that, in this embodiment, the needle seat and the needle cylinder are of an integrated structure. Of course, the needle seat and the needle cylinder can be in a separated detachable structure, and the injectors with the two structural forms are the prior mature technologies.

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

The structure of the plug 10 is as shown in fig. 12 and 13, and the plug is a tubular structure, and is provided with an internal fixing cavity 11, the internal fixing cavity 11 is adapted to the needle seat 50, the plug 10 is sleeved on the needle seat 50 through the internal fixing cavity 11, and the two are fixedly connected through conventional connection methods such as bonding, buckling, and the like.

In this embodiment, an accommodating plane 12 is disposed on an outer wall of the plug body 10, an elastic limiting member 13 is disposed on the accommodating plane near the front end, and the elastic limiting member 13 protrudes radially from a surface of the accommodating plane 12.

In this embodiment, the outer wall of the plug body 10 is further provided with two guide grooves 14 axially penetrating the outer wall, and the two guide grooves 14 are generally uniformly distributed along the circumferential direction of the plug body.

Further, an initial limiting groove 15 is further disposed on an outer wall of the plug body 10 of this embodiment, and a rear end of the initial limiting groove 15 is an open end.

The check member 20 of the present embodiment, as shown in fig. 14 to 16, includes a disk-shaped body 21 and a rod-shaped body 22 connected to an edge of the disk-shaped body 21 and extending in an axial direction toward a rear side of the disk-shaped body.

In this embodiment, the axial projection area of the disk-shaped body 21 is smaller than the axial projection area of the inner space of the sliding sleeve, so that the check member has enough space to freely topple over in the inner space of the sliding sleeve.

The non-return element 20 has a structure in which the inner side of the rod-shaped body 22 is fitted to the receiving plane 12, and the outer side of the rod-shaped body 22 is provided with an axially extending rib 26 and is configured such that the outer side of the rod-shaped body 22 extends from the rib 26 to the edge of the outer side of the rod-shaped body in a direction radially away from the inner surface of the sliding sleeve. When the outer side of the rod-shaped body 22 is supported on any supporting surface, the non-return elements will necessarily fall randomly on either side supported by the rib 26 as a line, due to the linear contact between the rib 26 and the supporting surface.

Preferably, in this embodiment, the rib 26 is provided at 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 on which the rib 26 is provided. The purpose of this arrangement is that the randomness of the pouring of the check to both sides is greater when the bead is in contact with any supporting surface.

In this embodiment, the disk-shaped body 21 is provided with a through hole 25 for receiving the injection needle 60 therethrough, and the projected area of the through hole 25 is much larger than the cross-sectional area of the injection needle.

Preferably, in the present embodiment, one side of the disk-shaped body 21 is provided with a slot 27 communicating with the through hole 25, and the slot 27 has the function that, during assembly, a needle does not need to be assembled in a way of passing through the through hole, and can enter the through hole from the slot from the side, so that the assembly way is more flexible, and the assembly efficiency is higher. Furthermore, the provision of the slots 27 results in an asymmetrical configuration of the sides of the disk-shaped body 21 with respect to the reference plane D, which configuration makes the rate at which the check will fall faster when the ridge is in contact with any supporting surface, due to the imbalance of the gravitational forces on the two sides of the reference plane.

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

As shown in fig. 18-20, the first sliding sleeve 31 is provided with an annular boss 313 at the periphery thereof, and the annular boss 313 divides the first sliding sleeve 31 into a front sliding sleeve 312 and a rear sliding sleeve 311. As shown in fig. 19, an annular cavity 316 is provided at a side of the annular boss 313 close to the front end sliding sleeve 312, an annular clamping groove 317 is provided at a position of the annular cavity 316 close to the cavity bottom, and an outer diameter of the annular clamping groove 317 is larger than that of the annular cavity 316.

In this embodiment, the inner wall of the first sliding sleeve 31 is provided with a receiving groove 318 for receiving the rod-shaped body 22. Wherein, as shown in fig. 9, the receiving groove 318 and the receiving plane 12 on the plug body 10 form a receiving space 70 for receiving the rod-shaped body 22. Further, the bottom of the receiving groove 318 therein is a step surface 319 for interaction 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, and the inner diameter of the inner flange 35 is larger than the outer diameter of the syringe and smaller than the outer diameter of the plug body, so as to prevent the sliding sleeve from axially disengaging from the plug body.

In this embodiment, an axial guiding mechanism is disposed between the first sliding sleeve 31 and the plug body 10. The axial guide mechanism functions 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 an inner wall of the first sleeve. Of course, as an equivalent embodiment, the guiding groove may also be disposed on the inner wall of the first sliding sleeve, and correspondingly, the guiding rib is disposed on the outer wall of the plug body.

In this embodiment, as shown in fig. 21, an annular snap 322 adapted to the annular snap 317 is disposed at the rear end of the second sliding sleeve 32, and the first sliding sleeve 31 and the second sliding sleeve 32 form the integral sliding sleeve 30 by the engagement of the annular snap 317 and the annular snap 322.

In this embodiment, to facilitate the annular snap edge entering the annular cavity 316, the edge of the annular cavity is chamfered.

It should be noted that the form of the snap-fit connection between the annular snap groove 317 and the annular snap edge 322 is only a preferred embodiment of the present embodiment, and as an equivalent embodiment, a plurality of sets of snap grooves and snap edges that are snap-fit to each other may be provided in the circumferential direction.

In this embodiment, the front end of the second sliding sleeve is provided with a front cover 321, and the front cover 321 is provided with a needle hole 323 for accommodating the injection needle. In the present embodiment, the check member is located between the inner side of the front cap 321 and the plug body.

Preferably, in the present embodiment, a first initial limiting mechanism is disposed between the first sliding sleeve 31 and the plug body 10, and as shown in fig. 7, 12, 13, 19 and 20, the first initial limiting mechanism includes an initial limiting groove 15 and a limiting protrusion 33 disposed on the plug body. When the sliding sleeve needs to be pushed, force enough for driving the limiting protrusion 33 to slide out of the initial limiting groove 15 needs to be applied, so that the first initial limiting mechanism has the function of keeping the sliding sleeve in the initial state, and the sliding sleeve can be prevented from being separated from the initial state due to misoperation due to the existence of the first initial limiting mechanism.

Preferably, as shown in fig. 13, a transition portion 17 is disposed at the bottom edge of the initial limiting groove 15, and the transition portion is a slope or a cambered surface, so as to reduce the resistance of the limiting protrusion 33 sliding out of the initial limiting groove 15.

In a preferred embodiment, the width of the rod-shaped body 22 is greater than the radial height of the ribs, so as to enhance the supporting strength of the check member, and at the same time, since the cross section of the rod-shaped body is close to rectangular, the rod-shaped body is difficult to enter the accommodating space again even if external force is applied after the rod-shaped body is overturned at a certain angle, thereby improving the reliability of the sliding sleeve in the extended state.

In a preferred embodiment, a second initial limiting mechanism is disposed between the check member 20 and the plug body 10, and as shown in fig. 6, 13 and 14, the second initial limiting mechanism includes an elastic limiting member 13 and a limiting groove 23 disposed at a position close to the disk-shaped body on the inner side surface of the rod-shaped body, and the elastic limiting member 13 is fittingly connected to the limiting groove 23.

In this embodiment, the elastic limiting member 13 at least covers a part of the accommodating space in the axial projection direction. The second initial limiting mechanism has the effect that the check piece and the sliding sleeve are kept in the initial state, and the resistance of the first initial limiting mechanism and the resistance of the second initial limiting mechanism are required to be overcome simultaneously when the sliding sleeve is pushed, so that misoperation can be prevented. In addition, because the elastic limiting piece 13 covers part of the accommodating space in the axial projection direction, when the sliding sleeve is pushed to the extending state, the rod-shaped body is separated from the accommodating space, and at the moment, the position of the rod-shaped body relative to the accommodating space is changed due to random overturning of the non-return piece, so that the rod-shaped body is difficult to be changed to the position where the rod-shaped body can enter the accommodating space again. Even because the uncertainty, under the effect of external force, the rod-shaped body has the position that can get into accommodation space just, because elasticity locating part is to accommodation space's cover, can the separation rod-shaped body get into accommodation space's route, so, increased a guarantee, further ensure that the sliding sleeve can't resume to initial condition again, the reliability is stronger.

The syringe needle protection device of this embodiment, its assembly method does, at first, locates the cylinder with first sliding sleeve cover on, the mode of entering is, and the rear end of first sliding sleeve gets into from syringe needle one end, is fixed in the cock body with the form that bonds on then, because the inner flange internal diameter of first sliding sleeve rear end is less than the external diameter of cock body, then first sliding sleeve can't be deviate from by the cock body end. Then, the first sliding sleeve is moved to the position of the initial state, and the rod-shaped body of the check piece extends into the accommodating space. And 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 sliding sleeve structure.

In the needle head protection device and the safety syringe thereof of the embodiment, in the initial state, as shown in fig. 6 and 7, the disc-shaped body of the check piece is positioned between the inner side of the front cover and the front end of the plug body, the rod-shaped body is positioned in the accommodating space, the front cover and the plug body of the sliding sleeve are only separated by the thickness of the disc-shaped body, the axial distance is very small, the invalid length of the injection needle is greatly reduced, and the axial space and the radial space between the sliding sleeve and the plug body are effectively utilized.

After injection is completed, the sliding sleeve is pushed axially to an extending state, under the action of the step surface, the rod-shaped body of the check piece is pushed out of the accommodating space, the state is as shown in fig. 3, in the state, no operation is needed, the check piece can randomly topple, for example, the state shown in fig. 4, and after the check piece is randomly toppled, the check piece is supported between the front cover of the sliding sleeve and the front end of the plug body, so that the injection needle is protected, and secondary use can be effectively avoided.

The needle head protection device and the safety syringe thereof have the technical advantages of simple structure, low cost, convenience in assembly, convenience in operation, safety and reliability.

In conclusion, the above description is only for the preferred embodiment of the present invention and should not be construed as limiting the present invention, and any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A needle protection device, comprising at least:

the plug body is fixedly arranged;

the check piece comprises a disc-shaped body and at least one rod-shaped body which is connected with the edge of the disc-shaped body and extends axially to one side of the disc-shaped body, an accommodating space for accommodating the rod-shaped body is arranged between the outer wall of the plug body and the inner wall of the sliding sleeve, a step surface which is configured on the inner wall of the sliding sleeve and interacts with the free end of the rod-shaped body is arranged in the accommodating space, a through hole is formed in the disc-shaped body, and the axial projection of the disc-shaped body is smaller than that of the inner space of the sliding sleeve;

wherein the check is configured to: in the initial state of the sliding sleeve, the disc-shaped body is positioned between the end part of the plug body and the end part of the sliding sleeve, and the rod-shaped body is positioned in the accommodating space; in the extending state of the sliding sleeve, the rod-shaped body is separated from the accommodating space, and the check piece is supported between the end part of the sliding sleeve and the end part of the plug body;

be provided with the initial stop gear of second between backstop and the cock body, the initial stop gear of second includes at least:

2. Needle protector according to claim 1, characterized in that the outer side of the rod is provided with an axially extending rib and arranged such that the outer side of the rod extends from the rib in a direction radially away from the inner surface of the slide to the edge of the outer side of the rod.

3. A needle protection device according to claim 2, characterised in that the disc is asymmetrical with respect to the datum plane in which the ridge lies.

4. A needle protection device according to claim 1, characterised in that said slide comprises a first slide and a second slide which snap into each other.

5. A needle protection device according to claim 1, characterised in that an axial guide means and/or a first initial stop means is provided between the sliding sleeve and the stopper body.

6. Needle protector according to claim 1, characterized by the fact that the said housing space comprises at least:

the accommodating groove is formed in the inner wall of the sliding sleeve; and

7. A needle protection device according to claim 6, characterised in that said plug body is provided with two mutually symmetrical receiving planes.

8. The needle protection device according to claim 1, wherein a guiding mechanism is disposed between the elastic limiting member and the limiting groove, the guiding mechanism comprising a first guiding inclined surface disposed on the elastic limiting member and a second guiding inclined surface disposed in the limiting groove and adapted to the first guiding inclined surface.

9. A safety syringe, characterized in that it comprises at least:

the needle seat is provided with an injection needle; and

the needle tip protector of any one of claims 1-8, said plug body fixedly attached to said needle hub, said needle passing through said via hole, said sliding sleeve covering said needle in an extended state of said sliding sleeve.