FR3038840A1 - SAFETY DEVICE FOR INJECTION SYRINGE. - Google Patents

Abstract

The injection syringe (12) comprises a syringe body (14) having an injection needle (28) and a piston, the safety device (10) comprising - a syringe holder, comprising means for fixing the syringe body (14) on the syringe holder, said first fixing means, - a protective sheath (34), the syringe holder and the protective sheath (34) being axially slidably mounted, one for each relative to each other between an injection position, during which the injection needle (28) protrudes from the protective sheath (34), and a protective position, during which the injection needle (28) is covered by the protective sleeve (34), - a piston rod (18) configured to be attached to the piston (20), - a retaining member (50) of the piston (20) configured to be attached. on the syringe holder from the proximal end (1 OP) once the syringe body (14) is assembled into the syringe holder, the retainer (50) defining a passage opening (52) of the plunger rod (18) having a shape preventing withdrawal of the plunger (20) from the syringe body (14) and also comprising means for fixing the retaining member (50) on the syringe holder, said second fixing means (54), these second fixing means (54) providing additional retention of the syringe body (14) in the holder syringe, to be added to the restraint provided by the first attachment means.

Description

Safety device for an injection syringe

The present invention relates to the field of safety devices for a liquid injection syringe, in particular for a pre-filled injection syringe.

Already known in the state of the art, including EP2047879 a safety device for a liquid injection syringe. Such a safety device makes it possible to inject liquid by sliding a piston in a syringe body, the injection being followed by an automatic retraction of the injection needle in a protective sheath. Thus, it is avoided that a person handling the safety device after injecting the liquid into the body of a patient does accidentally prick with the injection needle.

A difficulty lies in the fact that it may happen that the piston is removed from the syringe before injection, for example accidentally when a user pulls on the piston rod to make a vein test to verify that the needle of the syringe injection has or not stitched at a vein, or voluntarily according to another example when a third party wants to fraudulently collect a portion of the drug contained in the injection syringe. In both cases, such a withdrawal may impact the sterility, the quantity or the composition of the liquid to be injected. The object of the invention is in particular to improve the reliability of the safety device. For this purpose, the invention relates to a safety device for an injection syringe, the injection syringe comprising a syringe body provided with an injection needle and a piston, the safety device comprising a distal end disposed on the side of the injection needle and an opposite proximal end, the safety device comprising: a syringe holder, comprising means for attaching the syringe body to the syringe holder, said first attachment means , a protective sheath, the syringe holder and the protective sheath being each of generally tubular shape, mounted to slide axially relative to each other between an injection position, during which the needle of injection protrudes from the protective sheath, and a protective position, during which the injection needle is covered by the protective sheath, a piston rod config urea to be attached to the piston, a piston retainer configured to be attached to the syringe holder from the proximal end once the syringe body is assembled into the syringe holder, the retainer defining a passage opening of the piston rod having a shape preventing the removal of the piston from the syringe body and also comprising means for fixing the retaining member on the syringe holder, said second fixing means, these second means of fixing providing additional retention of the syringe body in the syringe holder, adding to the retention provided by the first fastening means.

Thus, it is proposed to report on the safety device, once the injection syringe assembled in the syringe holder, a retaining member which advantageously combines two functions. On the one hand, the retaining member prevents the piston from being removed accidentally or voluntarily from the syringe body before injection, thus guaranteeing the sterility, the quantity or the composition of the injected product. . On the other hand, the retaining member, being attached to the syringe holder, provides an additional retaining function of the injection syringe in the syringe holder. This advantage is particularly advantageous to ensure that the injection syringe is intact inside the safety device before use, especially after a fall which could have caused accidental deactivation of the first fastening means or even in case of fraudulent attempt of using the injection syringe out of the safety device before use. In other words, in addition to the fact that the piston can not be removed, it is ensured that the injection syringe per se can not leave the safety device.

It is understood that the second attachment means are separate means of the first fastening means. It will further be understood that an element is described as proximal or distal depending on whether it is near or far away from the end of the piston rod intended to be actuated by a user.

The security device may further comprise one or more of the following features, taken alone or in combination.

The second fixing means comprise at least two locking clips, preferably four locking clips, the locking clips being disposed at the periphery of the retaining member, each being carried by a tab extending towards the distal end. and cooperating with a proximal annular rim of the syringe holder. The piston retainer is thus attached to the syringe holder and forms a lid at the proximal end of the syringe barrel which prevents the exit of the syringe. In addition, the locking clips extend over a tab extending from the retaining member towards the distal end, so that they do not encumber the proximal end of the safety device which can remain compact in the axial direction, which would be different if latching means were provided above the retaining member. Moreover, with such a configuration, the retaining member can be optionally provided on the safety device, the other parts and their arrangement remaining unchanged, whether there is a retaining member or not. The passage opening has at least one transverse dimension less than a transverse dimension of the piston, for example if the piston has a circular cross section, the passage opening has an inside diameter smaller than the outside diameter of the piston. Thus, once the piston retaining member is attached to the syringe holder, the piston can not pass the passage opening and is thus prevented from exiting. The passage opening has a shape preventing the withdrawal of the piston rod from the syringe body, more precisely the piston rod comprises an enlarged distal end which is attached to the piston and which has at least one external transverse dimension greater than a transverse dimension of the passage opening. Thus, not only the piston can not be removed after the assembly of the retaining member, but it is the same for the piston rod. This avoids in particular that one can purposely disassemble the piston rod of the piston, for example by unscrewing it, to remove it from the safety device and change the composition of the liquid contained in the syringe. Note that the enlarged distal end of the piston rod is generally in the form of a plastic element covering the piston, which has the advantage of making even less accessible the piston in case of attempted extraction the contents of the injection syringe. Indeed, as the piston is generally elastomeric material, it may happen that malicious people plant an injection needle to take a portion of the contents of the injection syringe. The piston retaining member comprises a central extra thickness bearing against the syringe body. This extra thickness exerts a pressure towards the distal end on the syringe body, which is added to the immobilization of the latter in the syringe holder.

The protective sheath and the syringe support are retained in their injection position by the cooperation of complementary retractable retaining stops at the end of injection by a head of the piston rod, the piston retaining member having a clearance allowing these retainers discovered so that they are accessible by the head of the piston rod. Thus, the addition of the retaining member does not interfere with the usual operation of the safety device, that is to say its ability to correctly take its protective position. In addition, particularly advantageously, the retaining member may be optionally provided on the device. In other words, it can be provided that all other parts, except the retaining member, are the same as those used without retaining member and according to the same arrangement.

The syringe holder has a proximal annular rim bearing internal retaining lugs of the syringe body, these inner retaining lugs forming the first attachment means.

The syringe holder has a proximal annular edge including an abutment surface facing the distal end forming a retaining stopper for locking clips carried by the retaining member, these locking clips forming the second attachment means. During assembly, the locking clips engage with this abutment surface and provide attachment of the retainer, as well as attachment of the seringe body to the syringe holder.

The syringe holder has a proximal annular edge comprising an abutment surface oriented towards the proximal end, forming a retaining stop of a complementary retaining stop, retractable at the end of injection by a head of the plunger rod, worn by the protective sheath. The retaining member has a generally recessed disk shape provided at its periphery with locking clips extending towards the distal end of the safety device and the passage opening at the center of the disc, with a general shape. This form of hollow disc is particularly advantageous because it facilitates the assembly of the retaining member on the syringe holder. Indeed, the retaining member is last reported on the syringe holder, after assembly of the injection syringe and the piston rod. However, the piston rod comprises a proximal head, often considerably extended relative to an elongated portion of the piston rod, to allow the support of a finger of the user. The generally U-shaped passage opening allows the piston rod to be passed through the opening of U at the elongate portion of the piston rod without passing through the piston rod head. The invention also relates to a set of an injection syringe and a safety device as described above. The invention will be better understood on reading the appended figures, which are provided by way of example and are in no way limiting, in which: FIG. 1 is a perspective view of a set of an injection syringe and a safety device for the injection syringe, during assembly of the retaining member; Figure 2 is a view similar to that of Figure 1, after the assembly of the retaining member; Figure 3 is a sectional view of a portion of the assembly of Figure 2, without the piston rod or the piston; Figure 4 is a top view of a portion of the assembly of Figure 2, without the piston rod or the piston; Figure 5 is a sectional view of a portion of the assembly of Figure 1; Figure 6 is a sectional view of a portion of the assembly of Figure 2; Figure 7 is a perspective view from the distal end of a piston retainer according to one embodiment.

FIGS. 1 and 2 show an assembly comprising an injection syringe 12 and a safety device 10 for the injection syringe 12.

As shown in Figure 3, the injection syringe 12 comprises a syringe body 14 forming a liquid reservoir to be injected. The syringe body 14 includes an open proximal end 14P, provided with a flange 16, and a distal end, generally cone-shaped converging opposite the proximal end 14P. The distal end of the injection syringe 12 carries an injection needle 28 covered by a removable cap visible in FIGS. 1 and 2. The injection syringe 12 further comprises a piston 20, visible in FIGS. 6, for closing the syringe body 14 so that the liquid remains inside, the piston being slidably mounted in a sealed manner to allow the injection of liquid. The piston 20 has a circular cross section whose outer diameter is DP. The injection syringe 12 is preferably a pre-filled syringe made of glass. Generally, such an injection syringe 12 is filled by a pharmaceutical laboratory separate from the manufacturer of the safety device 10.

The safety device 10 includes a distal end 10D disposed on the side of the injection needle 28 and an opposite proximal end 10P. In this example, the safety device 10 is composed of a syringe holder 36, a protective sheath 34, a spring 42, a piston rod 18 and a retaining member 50 of the piston. . Of course, it may be possible for other parts to be added to the security device.

The syringe holder 36 comprises first attachment means 40 of the syringe body 14. More particularly, as illustrated in FIG. 3, the syringe body 14 is immobilized axially (possibly with a clearance) in the syringe holder 36 by snap-fastening. flange 16 between a support seat 38 formed in the syringe holder 36 and inner lugs 40 carried by a proximal annular edge 60 of the syringe holder 36. The proximal annular edge 60 also includes a stop surface 62 oriented towards the distal end intended to cooperate with the retaining member 50; and an abutment surface 46 oriented toward the proximal end 14P, intended to cooperate with the protective sheath 34. The syringe holder 36 is housed in the protective sheath 34 substantially coaxially with the latter. They are each of generally tubular shape, mounted sliding axially relative to each other between an injection position, during which the injection needle 28 protrudes from the protective sheath 34, and a protective position. during which the injection needle 28 is covered by the protective sheath 34.

The protective sheath 34 and the syringe holder 36 are retained in their injection position by cooperation of retaining stops 44, 46, complementary and retractable end of injection by a head of the piston rod 18. A first stop Retainer 44 visible in FIG. 4 is formed by the free end of an elastic axial tongue 45 formed in a proximal end of the protective sheath 34 and extending towards the distal end 10D. This axial tongue 45 is elastically deformable radially. The second retaining stop 46 is provided on the proximal end of the syringe holder 36. More specifically, the retaining stop 46 is provided on the upper surface, or proximal end, of the proximal annular edge 60. Preferably, the security 10 comprises two pairs of retaining stops 44, 46 diametrically opposed. The protective sheath 34 and the syringe holder 36 are preferably made of injection molded plastic. The retaining stops 44, 46 are means for retaining the syringe holder 36 in the injection position with respect to the protective sheath 34. These retaining means oppose the elastic force of the thrust spring 42. illustrated in FIG. 3, it can be seen that, in the position of disengagement of the injection needle 28, the spring 42 is housed in a groove 84 of generally annular shape, formed in this example in the proximal end of the sheath of FIG. protection 34. This groove 84 also ensures axial and radial positioning of the spring 42.

The piston rod 18, preferably made of plastic material, has a proximal end 18P, an elongated portion 18A and a distal end 18D. When the piston rod 18 is assembled on the piston 20, its proximal end 18P extends outside the syringe body 14 and forms an operating head. The distal end 18D is attached to the piston 20 within the syringe body 14, for example by screwing. The distal end 18D has an enlarged shape with respect to the allotted portion 18A. This enlarged shape has an outer transverse dimension Dtd which here corresponds to a diameter Dtd because the cross section of the enlarged shape is circular in this example. The retainer 50 of the piston 20 is configured to be attached to the syringe holder 36 from the proximal end 10P once the syringe body 14 is assembled into the syringe holder 36. In the example, as shown in FIG. see the best in Figure 4, the retainer 50 has a general shape of hollow disc and defines a passage opening 52 of the piston rod 18. The passage opening 52 occupies the center of the disc and has a shape A transverse dimension of the passage opening 52, ie the distance between the two branches of U, called D0, is smaller than the outside diameter DP of the piston 20. Preferably, the transverse dimension D0 is also smaller than the diameter. Dtd exterior of the distal end 18D of the piston rod 18. Thus, the shape of the retaining member 50 prevents not only withdrawal of the piston 20 from the syringe body 14, but also that of the Furthermore, the retaining member 50 comprises fastening means 54 of the retaining member 50 on the syringe holder 36, said second fixing means 54, in this case in the form of clips. locking 54 disposed at the periphery of the disc and each carried by a tab 56 extending towards the distal end. These locking clips 54, cooperating with the abutment surface 62 of the proximal annular edge 60, provide additional retention of the syringe body 14 in the syringe holder 36 because they are added to the restraint provided by the first fastening means. Furthermore, the retaining member 50 of the piston 20 has a clearance 58 leaving the retaining stops 44, 46 carried by the protective sheath 34 and the syringe holder 36 discovered, so that they are accessible by the head 18P of the piston rod 18. More specifically, the clearance 58 of the retaining member 50 leaves the axial tabs 45 discovered. As can be seen in particular in FIGS. 3 and 7, the retaining member 50 of the piston 20 also comprises a thickening 59 central bearing against the syringe body 14. Once the retaining member 50 of the piston 20 is assembled at the syringe holder 36, this extra thickness 59 then exerts a pressure towards the distal end on the syringe body 14, which adds to the maintenance of the latter in the syringe holder 36.

The assembly of the injection syringe assembly 12 and the safety device 10 will now be described. The assembly of the safety device 10, on the one hand, and the insertion of the injection syringe 12 into the safety device 10, on the other hand, are similar to that described in document FR-A-2 830 765. In a first step, the syringe holder 36 is fitted into the protective sheath 34 by compressing the spring 42 and is retained in the injection position relative to the protective sleeve 34. Then, the syringe body 14, pre-filled with liquid and closed by the piston 20, is inserted into the syringe holder 36 and immobilized axially by the first attachment means 40. Next, the piston rod 18 is inserted into the syringe body 14 and fixed to the piston 20 by screwing. Finally, the retaining member 50 of the piston 20 is attached to the syringe holder 36 from the proximal end. More specifically, as illustrated in Figures 1 and 5, the retaining member 50 is first inserted transversely around the piston rod 18 so that the passage opening 52 surrounds the piston rod 18 in its portion. 18A and the retaining member 50 of the piston 20 is then moved axially towards the distal end until the locking clips 54 engage with the abutment surface 62 of the proximal annular edge 60 of the syringe holder 36 Thus, the retaining member 50 of the piston 20 forms a safety piece which on the one hand prevents the withdrawal of the piston 20 from the syringe body 14, and on the other hand provides additional retention of the syringe body 14 in the syringe holder 36. With the exception of certain aspects which will be specified later, the operation of the safety device 10 is similar to that described in document FR-A-2 830 765.

It is understood that after the assembly of the safety device 10, the piston 20 can not be withdrawn from the syringe body 14 because the transverse dimension of the piston Dp is greater than the transverse dimension C 0 of the passage opening. 52.

Preferably, the plunger rod 18 can not be removed from the syringe body 14 by unscrewing the plunger 20 either, because the enlarged distal end 18D of the plunger rod 18 also has a superior outer transverse dimension Dtd to the transverse dimension D0 of the passage opening 52. In addition, the retention of the syringe body 14 is enhanced by the latching of the locking clips 54 with the proximal annular edge 60 of the syringe holder 36. Thus, in case of a fall which could have caused an accidental deactivation of the first fixing means, the retaining member 50 of the piston 20 makes it possible to keep the injection syringe 12 in the safety device 10. At the end of the injection, the user pushes the piston rod 18 to reach the end of injection position. Thanks to the presence of the clearance 58 of the retaining member 50 of the piston, the proximal end 18P of the piston rod 18 can access and cooperate with the elastic tongues 45 so as to separate the stops from one another. These retaining means being released, the spring 42 urges the syringe holder 36 so as to place the sheaths 34 and the syringe holder 36 in their position of protection of the injection needle 28. The invention is not limited to the embodiment shown and other embodiments will become apparent to those skilled in the art.

Claims (11)

A safety device (10) for an injection syringe (12), the injection syringe (12) comprising a syringe body (14) having an injection needle (28) and a plunger (20), the safety device (10) comprising a distal end (10D) disposed on the side of the injection needle (28) and an opposite proximal end (10P), the safety device (10) being characterized by it comprises: a syringe holder (36), comprising means for attaching the syringe body (14) to the syringe holder (36), said first attachment means (40), a protective sleeve (34), ), the syringe holder (36) and the protective sheath (34) being each generally tubular in shape, mounted to slide axially relative to one another between an injection position, during which the needle injection (28) protrudes from the protective sheath (34), and a protective position, during which the injection needle (28) is covered by the protective sleeve (34), a piston rod (18) configured to be attached to the piston (20), a retaining member (50) of the configured piston (20) to be attached to the syringe holder (36) from the proximal end (10P) after the syringe body (14) is assembled into the syringe holder (36), the retainer (50) defining a passage opening (52) of the piston rod (18) having a shape preventing withdrawal of the piston (20) from the syringe body (14) and also comprising means for fixing the retaining member (50) on the syringe holder (36), said second attachment means (54), said second attachment means (54) providing additional retention of the syringe body (14) in the syringe holder (36), in addition to the the retenue provided by the first fastening means (40). 2. Safety device (10) according to the preceding claim, wherein the second attachment means comprise at least two locking clips (54), preferably four locking clips, the locking clips (54) being arranged at the periphery. of the retaining member (50), each being carried by a tab (56) extending towards the distal end, and cooperating with a proximal annular edge (60) of the syringe holder (36). 3. Safety device (10) according to the preceding claim, wherein the passage opening (52) has at least one transverse dimension (Do) less than a transverse dimension of the piston (Dp), for example if the piston (20) ) has a circular cross section, the passage opening (52) has an inner diameter smaller than the outer diameter of the piston (20). The security device (10) according to any of the preceding claims, wherein the passage opening (52) has a shape preventing removal of the piston rod (18) from the syringe body (14), more precisely, the piston rod (18) comprises an enlarged distal end (18D) which is attached to the piston (20) and which has at least one external transverse dimension (Dtd) greater than a transverse dimension (Do) of the opening of passage. 5. Safety device (10) according to any one of the preceding claims, wherein the retaining member (50) of the piston comprises a thickening (59) central bearing against the syringe body (14). 6. Safety device (10) according to any one of the preceding claims, wherein the protective sheath (34) and the syringe holder (36) are retained in their injection position by cooperation of retaining stops (44). , 46) complementary retractable end of injection by a head (18P) of the piston rod (18), the retaining member (50) of the piston (20) having a clearance (58) leaving these retaining stops ( 44, 46) so that they are accessible through the head (18P) of the piston rod (18). A safety device (10) as claimed in any one of the preceding claims, wherein the syringe holder (36) has a proximal annular edge (60) carrying internal retaining lugs (40) of the syringe body (14). , these lugs (40) retaining interiors forming the first fastening means. The security device (10) of any preceding claim, wherein the syringe holder (36) has a proximal annular edge (60) having an abutment surface (62) facing the distal end (10D). ) forming a retaining stop of locking clips (54) carried by the retaining member (50), these locking clips (54) forming the second fastening means. The security device (10) according to any one of the preceding claims, wherein the syringe holder (36) has a proximal annular edge (60) including a stop surface (46) facing the proximal end (10P). ), forming a retaining stop of a complementary retaining stop (44), retractable end of injection by a head (18P) of the piston rod (18), carried by the protective sleeve (34). 10. Safety device (10) according to any one of the preceding claims, wherein the retaining member (50) has a general shape of hollow disc, provided at its periphery with locking clips (54) extending towards the distal end of the safety device (10) and the passage opening (52) occupies the center of the disc, with a general shape of U. An assembly of an injection syringe (12) and a safety device (10) according to any one of the preceding claims.