CN108619594B

CN108619594B - Safety syringe and safety mechanism therefor

Info

Publication number: CN108619594B
Application number: CN201710184681.5A
Authority: CN
Inventors: 林作钱
Original assignee: Sol Millennium Medical HK Ltd
Current assignee: Sol Millennium Medical HK Ltd
Priority date: 2017-03-24
Filing date: 2017-03-24
Publication date: 2021-08-13
Anticipated expiration: 2037-03-24
Also published as: CN108619594A; TW201834708A

Abstract

The invention discloses a safety syringe and a safety mechanism used for the same. The safety syringe (1) comprises: a barrel (2) having a proximal end (3), a distal end (4) and a chamber (5) therebetween defining a longitudinal axis, a needle holder (6) extending distally from the distal end; a plunger (7) having a distal portion inserted into the barrel from the proximal end of the barrel and a proximal portion located outside the barrel; a needle (8) having a proximal portion inserted into the needle channel of the needle holder from the distal side of the needle holder and a distal portion located outside the needle holder, the needle being hollow and in fluid communication with the chamber of the barrel; and a safety mechanism (9) mounted at least partially around the needle-holding portion, in an unactuated position of the safety mechanism, a distal portion of the needle is uncovered by the safety mechanism, and in an actuated position, at least a distal tip of the needle is covered by the safety mechanism to prevent accidental contact with the distal tip of the needle. According to the invention, the safety mechanism can be installed before the needle is installed when the syringe is assembled, so that the needle only needs to be calibrated once and does not interfere with the needle before the safety mechanism is activated.

Description

Safety syringe and safety mechanism therefor

Technical Field

The present invention relates to a safety syringe and a safety mechanism for a safety syringe.

Background

Accidental puncture by a used syringe can cause disease. Thus, the prior art teaches syringes having an actuatable safety shield that can be positioned to shield against accidental contact with the needle tip after use of the syringe. Prior art safety shields are provided with a barrier that shields the needle tip, the barrier having a needle passage through which the needle needs to be passed during assembly of the syringe to mount the safety shield with the barrier, which is time consuming and error prone due to the need to recalibrate the needle during mounting as the needle is difficult to reach.

Disclosure of Invention

The present invention has been made to solve the above-mentioned problems occurring in the prior art.

In one aspect, the present invention provides a safety syringe comprising: a barrel having a proximal end, a distal end, and a chamber therebetween defining a longitudinal axis, a needle holder extending distally from the distal end; a plunger having a distal portion inserted into the barrel from a proximal end of the barrel and a proximal portion located outside the barrel; a needle having a proximal portion inserted into the needle passageway of the needle holder from a distal side of the needle holder and a distal portion located outside the needle holder, the needle being hollow and in fluid communication with the chamber of the syringe; and a safety mechanism mounted at least partially around the needle-holding portion, in an unactuated position of the safety mechanism, a distal portion of the needle being uncovered by the safety mechanism, and in an actuated position of the safety mechanism, at least a distal tip of the needle being covered by the safety mechanism to prevent inadvertent contact with the distal tip of the needle.

Preferably, the safety mechanism is axially snap fitted at least partially around said needle-holding portion.

Preferably, the safety mechanism is freely rotatable around the needle holder.

Preferably, the safety mechanism comprises a guide locking member mounted at least partially around the needle holder and a protective member disposed at least partially around the needle holder and distal to the guide locking member, the protective member being movable from an unactuated position, in which the distal portion of the needle is not covered by the protective member, to an actuated position, in which at least the distal tip of the needle is covered by the protective member, the guide locking member and the protective member having means for releasably retaining the protective member in the unactuated position, means for guiding the protective member from the unactuated position to the actuated position, and means for locking the protective member in the actuated position.

Preferably, the guide lock member includes a sleeve portion mounted around the needle holding portion and a guide lock portion extending longitudinally proximally from an outer side of the sleeve portion.

Preferably, the protection member comprises a sleeve portion disposed around the needle holding portion distal to the sleeve portion of the guide locking member, an arm portion extending longitudinally proximally from an outer side of the sleeve portion of the protection member, and a finger contact portion at a proximal end of the arm portion.

Preferably, the means for releasably retaining the protective member in the unactuated position comprises a resilient tab on the guide lock portion of the guide lock member and a projection on the arm of the protective member disposed longitudinally towards one side of the resilient tab, at least a portion of the resilient tab on the guide lock portion being received distally of the projection in the unactuated position to retain the protective member in the unactuated position, the projection being shaped to allow the resilient tab on the guide lock portion to ride over the projection upon application of a distally directed finger force to the finger contact portion of the protective member to release the protective member from the unactuated position.

Preferably, the means for guiding the movement of the guard member from the unactuated position to the actuated position comprises at least one longitudinal guide slot on the guide lock of the guide lock member and at least one corresponding longitudinal flange on the arm of the guard member, a distal portion of the longitudinal flange being located within the longitudinal guide slot in the unactuated position, the longitudinal guide slot and the longitudinal flange being shaped to allow the longitudinal flange to slide distally along the longitudinal guide slot upon application of a distal finger force to the finger contact portion of the guard member until the finger contact portion comes into contact with the guide lock to stop.

Preferably, the mechanism for locking the protection member in the actuated position comprises a tab on the guide lock of the guide lock member and a projection on the arm of the protection member facing in the longitudinal direction towards one side of the tab, and at least one guide projection provided at the proximal end of the protection member and at least one recess provided corresponding to the guide lock of the lock member, the tab being capable of passing over and catching on the proximal side of the tab when the protection member is moved from the unactuated position to the actuated position, and the guide projection being received in the recess to lock the protection member in the actuated position at an inclination to the longitudinal axis.

Preferably, the inside of the sleeve portion of the guide and lock member is provided with a protrusion or recess which engages a recess or protrusion formed on the outside of the needle holder to axially snap the sleeve portion of the guide and lock member onto the needle barrel.

Preferably, the safety syringe further comprises a needle shield for shielding the needle and shaped to fit the shape of the safety mechanism.

Preferably, the inner surface of the needle shield is provided with at least one pair of ribs which slidingly engage with at least one flange on the guide lock of the guide lock member.

Preferably, the inner surface of the needle shroud is further provided with a pair of ribs which are in pressing engagement with wedge-shaped projections on the sleeve portion of the guide locking member.

Preferably, the outer surface of the needle shroud is provided with a projecting anti-slip strip.

Preferably, the sleeve portion of the protection member is formed in a cap shape with a top opening having a hole diameter smaller than an inner diameter of the sleeve portion main body of the protection member.

Preferably, the finger contact portion is shaped as a plate-like portion extending laterally outward from a proximal end of the arm portion of the protective member.

In another aspect, the invention provides a safety mechanism for a safety syringe, the safety mechanism being mounted at least partially around a needle holding portion of the safety syringe, in an unactuated position of the safety mechanism, a distal portion of the needle being uncovered by the safety mechanism, and in an actuated position of the safety mechanism, at least a distal tip of the needle being covered by the safety mechanism to prevent inadvertent contact with the distal tip of the needle.

Preferably, the safety mechanism is axially snap-fitted at least partially around the needle-holding portion.

Preferably, the safety mechanism is freely rotatable around the needle holder.

According to the present invention, since the safety mechanism is mounted on the needle-holding portion of the cylinder, it is possible to mount the safety mechanism first and then mount the needle when assembling the syringe, so that only one time of needle calibration is required and the needle is not interfered with until the safety mechanism is activated.

According to the invention, the safety mechanism can freely rotate around the needle holding part of the needle cylinder so as to be convenient for recognizing the needle point culture surface.

According to the invention, the safety mechanism achieves the purpose of deflecting the needle tip to one side along with the inclination formed when the guide bulge at the proximal end of the protective component is combined with the concave part of the guide locking component, so that the needle tip is hidden in the protective cover.

In addition, compared with the prior art, the safety syringe has simple structure, smooth surface, capability of being operated by one hand and better protection performance on the needle head, thereby preventing accidental puncture injury caused by the needle head.

Drawings

FIG. 1 is a perspective view of a safety syringe with a needle shield according to one embodiment of the present invention.

FIG. 2 is a side view of the safety syringe shown in FIG. 1 with the needle shield removed and the safety mechanism in the unactuated position.

Fig. 3 is a sectional view a-a of fig. 2.

Fig. 4 is a partially enlarged view of fig. 3.

FIG. 5 is a perspective view of the safety syringe of FIG. 1 with the needle shield removed.

FIG. 6 is a side view of the safety syringe shown in FIG. 1 with the needle shield removed and the safety mechanism in the activated position.

Fig. 7 is a sectional view B-B of fig. 6.

Fig. 8 is a cross-sectional view C-C of fig. 6.

Fig. 9 is a perspective view of a guide lock member according to an embodiment of the present invention.

Fig. 10 is a perspective view of a protective member according to an embodiment of the present invention.

FIG. 11 is a perspective view of a needle shield according to one embodiment of the present invention.

Fig. 12 is a perspective view of the needle shield of fig. 11 engaged with a guide lock member.

Detailed Description

The structure and operation of the safety syringe of the present invention, and particularly the safety mechanism thereof, will be explained with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that the safety mechanism of the present invention is not limited to syringes and may be applied to other medical devices, such as lancets and the like. Reference herein to "proximal", "distal", "proximal" and "distal" are all with respect to an injection procedure performed by a healthcare worker, with the side or end proximal to the healthcare worker performing the injection procedure being "proximal" and "proximal", and the side or end distal to the healthcare worker performing the injection procedure being "distal" and "distal".

FIG. 1 is a perspective view of a safety syringe with a needle shield according to one embodiment of the present invention. The safety syringe 1 comprises a barrel 2, a plunger 7, a needle 8, a safety mechanism 9 and optionally a needle shield 26. The barrel 2 has a proximal end 3, a distal end 4 and a chamber 5 between the proximal end 3 and the distal end 4 and defining a longitudinal axis, the chamber 5 being for containing a medicament for injection or the like. The needle holder 6 extends distally from the distal end 4 of the barrel 2. the needle holder 6 may be integrally formed with the barrel 2 or may be two pieces connected together. The needle holding portion 6 has a central needle passage for receiving a portion of the needle and holding the needle. The plunger 7 has a distal portion which is inserted into the barrel 2 from the proximal end 3 of the barrel and a proximal portion which is located outside the barrel. The needle 8 has a proximal portion inserted into the needle channel of the needle holder 6 from the distal side of the needle holder 6 and a distal portion located outside the needle holder 6, is hollow, is inserted into the needle channel of the needle holder 6 and is in fluid communication with the chamber 5 of the syringe 2. The safety mechanism 9 is mounted at least partially around the needle holding portion 6, in an unactuated position of the safety mechanism 9 a distal portion of the needle 8 is not covered by the safety mechanism 9, and in an actuated position of the safety mechanism 9 at least a distal tip of the needle 8 is covered by the safety mechanism 9 to prevent accidental contact with the distal tip of the needle 8. The safety mechanism 9 may be made of thermoplastic or any other suitable material. An optional needle shield 26 is provided to shield the needle 8 and is shaped to fit the shape of the safety mechanism 9.

The safety mechanism 10 according to one embodiment of the present invention will be described in detail below. FIG. 2 is a side view of the safety syringe shown in FIG. 1 with the needle shield removed and the safety mechanism in the unactuated position. Fig. 3 is a sectional view a-a of fig. 2. Fig. 4 is a partially enlarged view of fig. 3. Referring to fig. 2 to 4, the safety mechanism 9 is axially snapped at least partially around the needle holder. In another embodiment, the safety mechanism 9 is freely rotatable around the needle holding portion to facilitate the identification of the needle tip culture surface. The safety mechanism 9 comprises a guide locking member 10 and a protection member 11. The guide lock member 10 includes a sleeve portion 12 fitted around the needle holding portion 6 and a guide lock portion 13 extending proximally in the longitudinal direction from the outside of the sleeve portion 12.

The inside of the sleeve portion 12 of the guide and lock member 10 may be provided with a protrusion 24, and the protrusion 24 may engage a recess 25 formed on the outside of the needle holder 6 to axially snap the sleeve portion 12 of the guide and lock member 10 onto the needle cartridge. Conversely, the inside of the sleeve portion 12 of the guide and lock member 10 may be provided with a recess which may engage a protrusion formed on the outside of the needle holder 6 to axially snap the sleeve portion 12 of the guide and lock member 10 onto the barrel. In the embodiment shown in fig. 2 to 4, the outer diameter of the needle holder 6 is smaller than the outer diameter of the needle cylinder 2, whereby a retaining shoulder is formed at the interface of the needle holder 6 and the needle cylinder 2, a flange is provided on the needle holder 6 at a longitudinal distance from this interface, and a recess 25 for receiving a projection 24 inside the sleeve part 12 of the guide and lock member 10 is formed between the retaining shoulder and the flange for axially snapping the sleeve part 12 of the guide and lock member 10 on the needle cylinder.

The protection member 11 may include a sleeve portion 14 provided around the needle holding portion 6 distally of the sleeve portion 12 of the guide lock member 10, an arm portion 15 extending proximally in the longitudinal direction from the outside of the sleeve portion 14 of the protection member 11, and a finger contact portion 16 at the proximal end of the arm portion 15 (refer to fig. 10). The finger contact portion 16 of the protective member 11 is preferably shaped as a plate-like portion extending laterally outward from the proximal end of the arm portion 15 of the protective member 11. More preferably, the plate-shaped portion is provided with small protrusions on the surface thereof to increase the tactile sensation when the medical staff pushes the protection member 11 with the fingers. The protective member 11 may be moved from the unactuated position (shown in fig. 3) to the actuated position (shown in fig. 7) by applying finger pressure to the finger contact portion 16. In the unactuated position, the distal portion of the needle 8 is not covered by the protection member 11, and in the actuated position, at least the distal tip of the needle 8 is covered by the protection member 11.

The guide locking member 10 and the protection member 11 may have a mechanism for releasably holding the protection member 11 in the non-actuated position, a mechanism for guiding the protection member 11 to move from the non-actuated position to the actuated position, and a mechanism for locking the protection member 11 in the actuated position.

The means for releasably retaining the protective member 11 in the unactuated position may comprise a spring tab 17 (see fig. 9) on the guide locking portion 13 of the guide locking member 10 and a projection 19 (see fig. 10) on the arm portion 15 of the protective member 11 disposed longitudinally toward the spring tab 17 side. Preferably, the spring 17 is a tab projecting angularly distally from the guide-locking portion 13, provided with a catch able to catch on the distal end 20 of a lug 19 on the arm 15 to hold the protection member in the unactuated position. According to another embodiment, a plurality of projections 19 may be provided along the longitudinal direction of the arm portion 15 of the protective member 11. The projection 19 is shaped to allow the resilient tab 17 on the guide locking portion 13 to ride over the projection 19 to release the protective member from the unactuated position when a distally directed finger force is applied to the finger contact portion of the protective member.

The means for guiding the movement of the protection member 11 from the non-activated position to the activated position comprise at least one longitudinal guide slot 21 on the guide locking portion 13 of the guide locking member 10 and at least one corresponding longitudinal flange 22 on the arm portion 15 of the protection member 11. Preferably, a longitudinal guide groove 21 is provided on each of the left and right sides of the guide guard portion 13, and a longitudinal flange 22 is provided on each of the arm portions 15 of the guard member 11 at a position corresponding to the longitudinal guide groove 21. In the unactuated position, a distal portion of the longitudinal flange 22 is located within the longitudinal guide slot 21, the longitudinal guide slot 21 and the longitudinal flange 22 being shaped to allow the longitudinal flange 22 to slide distally along the longitudinal guide slot 21 upon application of a distally directed finger force to the finger contact portion 16 of the protective member 11 until the finger contact portion 16 comes into contact with the guide lock 13 to stop.

The mechanism for locking the protective member 11 in the activated position comprises a spring tab 17 on the guide lock 13 of the guide lock member 10 and a projection 19 on the arm 15 of the protective member arranged longitudinally towards the side of the spring tab 17, and at least one guide projection 18 provided at the proximal end of the protective member and at least one recess 29 provided on the guide lock of the locking member. Preferably, one guide projection 18 is provided on each of the left and right sides of the proximal end of the protective member, and correspondingly one recess 29 is provided on each of the left and right sides of the proximal end of the guide locking portion of the locking member. Also, preferably, the sleeve portion 14 of the protection member 11 is formed in a cap shape with a top opening 27, the diameter of the top opening 27 being smaller than the inner diameter of the sleeve portion main body 28 of the protection member. When the protection member is moved from the unactuated position to the actuated position, the resilient tab 17 is able to pass over the boss 19 and catch on the proximal side 23 of the boss 19 (as shown in fig. 7) and the guide boss 18 is received in the recess 29 (as shown in fig. 8), which causes the longitudinal axis of the protection member 11 in the actuated position to be angled with respect to the longitudinal axis of the syringe, which in turn causes the needle to not be aligned with the top opening 27 of the cap-shaped sleeve portion 14 of the protection member 11, but to abut against the inner wall of the sleeve portion body, further increasing the safety against needle sticks.

According to another embodiment of the invention, the means for guiding the locking member 10 and the protective member 11 for releasably retaining the protective member in the unactuated position, the means for guiding the protective member to move from the unactuated position to the actuated position, and the means for locking the protective member in the actuated position may comprise: a projection arranged along the longitudinal direction on the guide locking part of the guide locking member and a spring sheet facing one side of the projection on the arm part of the protection member; at least one longitudinal flange on the guide locking portion of the guide locking member and at least one corresponding longitudinal groove on the arm portion of the protection member; and the projection provided on the guide lock portion of the guide lock member in the longitudinal direction and the resilient piece provided on the arm portion of the protection member facing the projection side, and the at least one recessed portion provided at the proximal end of the protection member correspond to the at least one projecting portion provided on the guide lock portion of the lock member, as long as the movement of the protection member from the unactuated position to the actuated position can be achieved.

FIG. 11 is a perspective view of a needle shield 26 according to one embodiment of the present invention. As shown, the inner surface of the needle shroud 26 is provided with a pair of ribs 31 on either side of the cutaway portion, each pair of ribs 31 engaging a respective flange 30 on the guide lock 13 of the guide lock member. In addition, the inner surface of the needle shroud 26 is provided with a pair of ribs 32, preferably the pair of ribs 32 being located circumferentially about midway between the two pairs of ribs 31 and engaging with wedge-shaped projections 33 on the sleeve portion 12 which guide the locking member. With the protective member 11 in the unactuated position, the needle shield 26 is moved over the needle 8 from the distal to the proximal side of the needle 8, during which movement the ribs 31 on the inner surface of the needle shield 26 slidingly engage the flanges 30 on the guide lock 13 of the guide lock and the ribs 32 on the inner surface of the needle shield 26 are in pressing engagement with the wedge-shaped projections 33 on the sleeve portion 12 of the guide lock to securely fix the needle shield 26 (see fig. 12). In addition, the outer surface of the needle shroud 26 is provided with a projecting anti-slip strip 34 to facilitate removal of the needle shroud 26 in use.

While the particular arrangements of the invention have been described with reference to the particular embodiments shown in the drawings, it will be understood by those skilled in the art that the foregoing is illustrative and that various changes and modifications may be made therein without departing from the scope of the invention.

Claims

1. A safety syringe (1) comprising:

a barrel (2) having a proximal end (3), a distal end (4) and a chamber (5) therebetween defining a longitudinal axis, a needle holder (6) extending distally from the distal end;

a plunger (7) having a distal portion inserted into the barrel from a proximal end of the barrel and a proximal portion located outside the barrel;

a needle (8) having a proximal portion inserted into the needle channel of the needle holder from the distal side of the needle holder and a distal portion located outside the needle holder, the needle being hollow and in fluid communication with the chamber of the barrel; and

a safety mechanism (9) mounted at least partially around the needle-holding portion, in an unactuated position of the safety mechanism, a distal portion of the needle being uncovered by the safety mechanism, in an actuated position of the safety mechanism, at least a distal tip of the needle being covered by the safety mechanism to prevent accidental contact with the distal tip of the needle,

wherein the safety mechanism (9) comprises a guide locking member (10) mounted at least partially around the needle holder and a protective member (11) arranged at least partially around the needle holder and distally of the guide locking member, the protective member being movable from an unactuated position, in which the distal part of the needle is not covered by the protective member, to an actuated position, in which at least the distal tip of the needle is covered by the protective member, the guide locking member and the protective member having means for releasably retaining the protective member in the unactuated position, means for guiding the protective member from the unactuated position to the actuated position, and means for locking the protective member in the actuated position,

wherein the guide locking member comprises a sleeve portion (12) fitted around the needle holding portion and a guide locking portion (13) extending longitudinally proximally from an outer side of the sleeve portion,

wherein the protection member comprises a sleeve portion (14) arranged around the needle holding portion distally of the sleeve portion of the guide and lock member, an arm portion (15) extending proximally in a longitudinal direction from an outer side of the sleeve portion of the protection member, and a finger contact portion (16) at a proximal end of the arm portion,

wherein the means for releasably retaining the protective member in the unactuated position comprises a resilient tab (17) on the guide lock portion of the guide lock member and a projection (19) on the arm of the protective member disposed longitudinally on a side facing the resilient tab (17), the resilient tab (17) being laterally spaced from the means for guiding the protective member from the unactuated position to the actuated position, in the unactuated position at least a portion of the resilient tab on the guide lock portion being received distally of the projection to retain the protective member in the unactuated position, the projection (19) being shaped to allow the resilient tab on the guide lock portion to ride up the projection upon application of a distally directed finger force to the finger contact portion of the protective member to release the protective member from the unactuated position.

2. The safety syringe (1) according to claim 1, wherein the safety mechanism (9) is axially snapped at least partially around the needle holder.

3. The safety syringe (1) according to claim 1, wherein the safety mechanism (9) is freely rotatable around the needle holder.

4. The safety syringe (1) according to claim 1, wherein the means for guiding the movement of the protective member from the unactuated position to the actuated position comprise at least one longitudinal guide slot (21) on the guide lock of the guide lock member and at least one corresponding longitudinal flange (22) on the arm of the protective member, a distal portion of the longitudinal flange being located within the longitudinal guide slot in the unactuated position, the longitudinal guide slot and longitudinal flange being shaped to allow the longitudinal flange to slide distally along the longitudinal guide slot upon application of a distal finger force to the finger contact of the protective member until the finger contact comes into contact with the guide lock to stop.

5. Safety syringe (1) according to claim 4, wherein the means for locking the protection member in the activated position comprise the tab on the guide lock of the guide lock member and the projection (19) provided longitudinally on the arm of the protection member facing the side of the tab (17) and at least one guide projection (18) provided at the proximal end of the protection member and at least one recess (29) provided correspondingly on the guide lock of the locking member, over which the tab can pass and catch proximally of the tab when the protection member is moved from the unactivated position to the activated position, and in which the guide projection is received so that the protection member is locked in the activated position with a slope to the longitudinal axis.

6. The safety syringe (1) according to claim 1, wherein the inside of the sleeve portion of the guide and lock member is provided with a protrusion (24) or a recess which engages a recess (25) or a protrusion formed on the outside of the needle holder to axially snap-fit the sleeve portion of the guide and lock member on the needle cylinder.

7. The safety syringe (1) according to any of claims 1 to 3, further comprising a needle shield (26) for housing the needle and shaped to fit the shape of the safety mechanism.

8. The safety syringe (1) according to claim 7, wherein the inner surface of the needle shield (26) is provided with at least one pair of ribs (31), the at least one pair of ribs (31) being in sliding engagement with at least one flange (30) on the guide lock (13) of the guide lock member.

9. The safety syringe (1) according to claim 8, wherein the inner surface of the needle shield (26) is further provided with a pair of ribs (32), the pair of ribs (32) being in pressing engagement with wedge-shaped projections (33) on the sleeve portion (12) of the guide and lock member.

10. The safety syringe (1) according to claim 9, wherein the outer surface of the needle shield (26) is provided with a protruding anti-slip strip (34).

11. The safety syringe (1) according to claim 1, wherein the sleeve portion of the protective member is formed in a cap shape with a top opening (27) having a smaller bore diameter than an inner diameter of the sleeve portion body (28) of the protective member.

12. The safety syringe (1) according to claim 1, wherein the finger contact portion is shaped as a plate-like portion extending laterally outward from a proximal end of the arm portion of the protective member.

13. A safety mechanism (9) for a safety syringe (1), the safety mechanism being mounted at least partially around a needle holder of the safety syringe, in an unactuated position of the safety mechanism a distal portion of a needle being uncovered by the safety mechanism, in an actuated position of the safety mechanism at least a distal tip of the needle being covered by the safety mechanism to prevent accidental contact with the distal tip of the needle,

14. The safety mechanism (9) according to claim 13, wherein the safety mechanism (9) is axially snapped at least partially around the needle holder.

15. The safety mechanism (9) according to claim 13, wherein the safety mechanism (9) is freely rotatable around the needle holder.

16. The safety mechanism (9) according to claim 13, wherein the means for guiding the movement of the protective member from the unactuated position to the actuated position comprises at least one longitudinal guide slot (21) on a guide lock of the guide lock member and at least one corresponding longitudinal flange (22) on an arm of the protective member, a distal portion of the longitudinal flange being located within the longitudinal guide slot in the unactuated position, the longitudinal guide slot and longitudinal flange being shaped to allow the longitudinal flange to slide distally along the longitudinal guide slot upon application of a distal finger force to the finger contact portion of the protective member until the finger contact portion comes into contact with the guide lock to stop.

17. A safety mechanism (9) according to claim 16, wherein the means for locking the protective member in the activated position comprises the resilient tab on the guide lock of the guide lock member and the projection (19) on the arm of the protective member disposed longitudinally to the side of the resilient tab (17) and at least one guide projection (18) provided at the proximal end of the protective member and at least one recess (29) provided on the guide lock of the locking member correspondingly, the resilient tab being able to pass over the projection and catch proximally of the projection when the protective member is moved from the unactuated position to the actuated position and the guide projection being received in the recess to lock the protective member in the activated position at an inclination to the longitudinal axis.

18. Safety mechanism (9) according to claim 13, wherein the inside of the sleeve portion of the guide and lock member is provided with a protrusion (24) or a recess engaging a recess (25) or a protrusion formed on the outside of the needle holder to axially snap the sleeve portion of the guide and lock member on the needle cylinder.

19. The safety mechanism (9) according to claim 13, wherein the sleeve portion of the protective member is formed in a cap shape with a top opening (27) having a smaller bore diameter than an inner diameter of the sleeve portion body (28) of the protective member.

20. The safety mechanism (9) according to claim 13, wherein the finger contact portion is shaped as a plate-like portion extending laterally outward from a proximal end of the arm portion of the protective member.