FR2832932A1 - SAFETY DEVICE FOR PARENTERAL INJECTION SYRINGE, SINGLE USE - Google Patents

Abstract

The invention concerns a safety device comprising a) a safety housing (10) mobile along the axis of the syringe (1 to 6) between first and second positions wherein the housing (10) respectively protects and clears the free end of the syringe needle, the housing (10) being stressed by a spring (13) towards its first position, and b) means (14, 26, 14', 29<sb>1</sb>, 29<sb>2</sb>; 14'', 34<sb>1</sb>, 34<sb>2</sb>) to lock the housing (10) in its first position when the housing (10) returns in said position under the action of the spring (13), after a first shift of the housing (10) from its first to its second position.

Description

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The present invention relates to a safety device for a single-use syringe, equipped with a needle for injecting medication by parenteral route.

Today, such pre-filled syringes are commonly found, approved and registered by pharmaceutical laboratories, comprising, as shown in FIG. 1 of the appended drawing, a cylinder body 1 closed on one side by a piston 2 operated by a rod. control 3 and extended on the other side by an intradermal, subcutaneous, intramuscular or intracavernous injection needle, for example. This needle is protected by a removable finger 5, made of synthetic rubber for example.

The body 1 is filled with a volume 6 of a liquid containing, in solution or in suspension, a drug to be administered to a patient.

To carry out this administration, the protective finger is manually removed, the needle is pricked on the patient's skin and the liquid is expelled from the syringe by manually pushing the rod 3 into the body 1 of this syringe. After injection of the drug and removal of the needle from the patient's body, the needle is in the open air. If the protective finger is neglected to reattach the syringe, this needle may accidentally prick another person with the risk of spreading a disease affecting the patient being treated.

In addition, although such a syringe is proposed for single use, nothing then prohibits filling it again, after a first use, to administer other products to other people, with the risk mentioned above.

To overcome these drawbacks, special syringes have been designed, provided with means incorporated into the syringe and designed to prevent reuse thereof, after first use. The means designed for this purpose have the drawback of being integrated and specific to the syringe which is therein.

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equipped. They cannot therefore be used to secure a conventional single-use, pre-filled syringe without modifying the structure thereof.

The object of the present invention is precisely to provide such a safety device adaptable to a conventional single-use, pre-filled syringe, this adaptation being able to be done very simply because it does not require any modification of the structure of the syringe. herself.

These aims of the invention, as well as others which will appear on reading the following description, are achieved with a safety device for a single-use syringe equipped with a needle for injecting drug by parenteral route, this device being remarkable in that it comprises: a) a safety casing movable along the axis of said syringe between first and second positions in which said casing protects and releases, respectively, the free end of said needle, said casing being loaded by a spring towards its first position, and b) means for locking said casing in said first position when the casing returns to this position under the action of said spring, after a first passage of the casing from its first to its second position.

As will be seen in detail below, the device according to the invention can be installed on a conventional syringe, very easily and quickly, by inserting the body and the needle of the syringe into a cylindrical sheath forming part of this device and designed to receive the latter coaxially, in an irremovable manner, the safety casing being slidably mounted on the sheath.

Locked in its second position, after an injection, the housing prevents any further contact of the syringe needle with the skin of another person.

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According to other optional characteristics of the present invention: said locking means comprise a ring of flexible material mounted coaxially on said protective casing so that, said casing passing from its first to its second position, said ring is pushed. from an initial position to a final position in which it is integral with said casing and said sleeve, respectively, said ring expanding radially in said casing when the latter returns from its second to its first position, to then abut on a shoulder internal circular of said housing by blocking any return of the housing to its second position, - said ring comprises a plurality of elastic tabs projecting from one of its bases radially outwards and a circular rim projecting inwardly from the other of its bases for snap into at least one complementary notch formed in the outer wall of said sheath when said safety casing p from its first to its second position, - said locking means comprise a ring mounted to rotate on said housing, inside and in a predetermined axial position thereon, at least one cam projecting internally from said ring to cooperate with a cam follower formed in the side wall of said sleeve, said cam follower being profiled so that said casing passing successively from its first to its second position to finally return to the first, said cam finally reaches one end of said follower cam shaped to oppose an axial return of said cam, and of the casing on which it is mounted, in the second position of said casing, - said locking means comprise a ring mounted for rotation on said sleeve and provided with at least one cam cooperating with a follower formed in the wall

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of said protective casing, and at least one pawl formed in the sleeve, said follower being profiled so that the casing retains said pawl in an inactive position until it returns to its first position, position beyond which it is then pushed by said spring to release the pawl which then engages in a notch of said casing so as to prevent any return thereof to its second position, - the device comprises means, distributed between said ring and the inner wall of said casing, to force the ring to rotate when said casing is pushed from its first to its second position, - said locking means further comprise stop means for preventing said casing from escaping from said sleeve, under the pressure of said spring, from from its first position, - the device comprises a protective cover designed to be removably and coaxially mounted on the safety casing, - said cover comprises means for p rehension of a protective finger of the needle of the syringe, suitable for allowing the simultaneous extraction of the cover and of said finger, before the execution of an injection, - the device constitutes a set of preassembled parts, ready to receive a commercial syringe to be secured, designed for single use.

Other characteristics and advantages of the present invention will become apparent on reading the description which follows and on examining the appended drawing in which: FIG. 1 is a view in axial section of a first embodiment of the device according to the invention, mounted on a syringe which it secures, FIGS. 2 to 6 are views of parts forming part of the device of FIG. 1,

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FIGS. 7A to 7C are views in axial section similar to those of FIG. 1, showing three successive states of the device according to the invention, these views being useful for explaining the operation of this device, FIG. 8 is a view in axial section of a safety casing fitted to a second embodiment of the device according to the invention, FIGS. 9A to 9D are partial schematic views useful for explaining the operation of this second embodiment, FIGS. 10 to 13 are views of parts forming part of a third embodiment of the device according to the invention, FIGS. 14A to 14C are views useful for explaining the operation of this third embodiment, and FIGS. 15A to 15B are enlarged sectional views along the section line A of Figures 14A and
14C respectively.

Reference is made to FIG. 1 of the appended drawing, which shows a first embodiment of the device according to the invention, mounted on a conventional syringe (1 to 6) described in the preamble of the present description. In this figure it appears that the device comprises a substantially cylindrical sheath 7, dimensioned to closely receive the body 1 of the syringe. A retaining ferrule 8, inserted in a groove formed in two end tabs 91, 92 of the sheath 7, makes it possible to retain the syringe therein. These tabs and this groove are better visible in the view in axial section of the sheath 7 shown in FIG. 2 and in the view in FIG. 3, taken along the arrow f1 in FIG. 2.

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The ferrule 8 can advantageously be made non-removable by bonding or ultrasonic welding.

The actuating rod 3 of the piston 2 initially protrudes from the end of the sleeve 7 where this ring is fixed, as shown.

The needle 4 protrudes from the other end of the sheath 7. On this other end of the sheath is mounted axially sliding, according to the invention, a safety casing 10. The casing 10 is of substantially cylindrical shape, and it is open. at both ends, as is best seen in the sectional view of this part, shown in Figure 5.

In this FIG. 5, it appears that the wall of the casing 10 is cut out by axial slots 111, 112 in which pass stops 121, 122 respectively formed on the outer surface facing the sleeve 7 (see Figures 2 and 3).

A helical spring 13 (see Figure 1) axially loads the casing 10 away from the sleeve 7, the latter however retaining this casing by the contact of the stops 121, 122 with the lower ends (from the point of view of Figures 1 and 5) lights 111, They.

In the position shown in Figure 1, the bottom 10a of the housing 10 still coaxially retains a ring 14, shown in axial section in Figure 6. This ring is made of a flexible material and comprises a plurality of tabs 151, 152, etc. , 4 legs for example, projecting slightly, radially and outwards, from a base of the ring. From the other base of the ring protrudes a circular rim 16 facing inward. The role of these parts of the ring 14 will be explained below.

The device according to the invention is completed by a protective cover 17 (see FIG. 1 and the view in axial section of this cover, shown in FIG. 4) which is also substantially cylindrical, designed to be detachably attached.

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on the safety casing 10, thanks to internal protuberances 181, 182 arranged and dimensioned to elastically enter the slots 111, 112 (see FIG. 1) next to the stops 121, 122 of the sleeve 7.

According to the invention, this cover 17 is provided with gripping means 19, for example of the wedge effect type, which pinch one end of the finger 5 protecting the needle 4 of the syringe, in the state of the device according to the invention shown in Figure 1, where the cover 17 is inserted on the sleeve 7 until it comes into abutment on stops 201, 202 formed on the outer surface of the sleeve (see also Figures 2 and 3). The advantage of these means for gripping the cover 17 will appear in the remainder of the present description.

The sleeve 7, the casing 10, the ring 14, the spring 4 and the cover 17, assembled as shown in FIG. 1, thus form a set of integral parts, easy to handle.

To secure the pre-filled syringe (1 to 6) also shown in this figure, we simply insert the body 1 of this syringe and its needle 4, protected by the finger 5, in this assembly, until a rim end 21 of this body abuts on a shoulder 22 (see Figures 1 and 2) of the end of the sleeve 7 which carries the tabs 91, 92. The locking collar 8 is then installed between the tabs 911 92 and makes it irremovable, possibly by gluing or welding, as we have seen above.

The syringe equipped with the device according to the invention is thus ready for use.

To do this, the protective cover 17 is first removed, which at the same time causes, thanks to the gripping means 19 described above, the removal of the finger 5 protecting the needle. The safety guard 10 is then

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clear but still protects the needle which surrounds it, from any contact with the outside.

To make an injection, the end of the casing is applied against the skin 23 (see FIG. 7A) of a patient to whom the drug contained in volume 6 of the syringe is to be administered and the end of the casing 10 is pressed. against the patient's skin, in the direction of arrow f2 in FIG. 7A. The casing 10 then leaves its first, initial position on the sheath, by sliding on it in the direction opposite to that of the arrow 2, which has the effect of releasing the end of the needle 4, previously surrounded by the safety cover, and to press it under the skin 23 of the patient (see FIG. 7B). The housing thus reaches a second position, shown in this figure.

This movement of the housing 10 has the effect of passing two axial fingers 241, 242, arranged symmetrically at the end of the sleeve 7 adjacent to the housing 10 (see Figures 2 and 3), against the internal surface of the ring 14, retained until 'then in the bottom 10a of the casing 10. The rim 16 of this ring 14 is elastically received in notches 251, 252 formed at the base of the fingers 2411 242. The ring 14 is therefore then secured to the sleeve 7, while remaining in its initial position, at the bottom of the housing 10.

The operating rod 3 of the piston 2 is then pushed into the body 1 of the syringe to inject the liquid medicine that it contains into the body of the patient. When the volume 6 of the syringe is substantially emptied, the needle is withdrawn from the patient, which has the effect of returning the housing 10, under the pressure of the spring 13, to its first position, relative to the sheath 7 (see FIG. 7C ).

In doing so, the sleeve 7 removes the ring 14 from the bottom 10a of the casing 10, the bottom in which the tabs 15l were radially loaded towards the axis of the casing by the side wall of this casing. The legs 15l then cross a

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annular shoulder 26 (see FIG. 5) defining an enlargement of the internal diameter of the casing 10, and relax by coming to rest on this shoulder (see FIG. 7C).

According to a characteristic of the present invention, the tabs 15l of the ring 14 then oppose any return of the casing 10 to its second position in FIG. 7B, because this ring 14 blocks any movement of the casing 10 on the sleeve 7. in the direction opposite to that of arrow f2, which could result in the end of needle 4 coming out dangerously from the end of housing 10.

In the position of the housing 10 shown in FIG. 7C, it further appears that the stops 121, 122, (see also FIGS. 2 and 3) oppose the extraction of the housing 10, in the direction of arrow f2.

It appears that thus, in accordance with the aim pursued by the present invention, the needle of a syringe secured using the "non-return" device according to the present invention is perfectly protected from any contact after its first use, the latter remaining unique due to the fact that the needle becomes permanently inaccessible immediately after this first use.

According to another advantageous characteristic of the present invention, this result is obtained using an inexpensive device because it consists of a small number of parts that are easy to assemble and to mount on a common syringe, without this assembly having to do with it. requires no structural modification of this syringe.

There is shown in Figures 8 to 9D and 10 to 15 of the accompanying drawing, respectively, second and third embodiments of the device according to the invention, respectively.

These embodiments are essentially distinguished from the first by the structure and the relationships of the ring.

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locking with the safety guard and the sleeve. The following description of these embodiments will therefore be limited to those of their characteristics which distinguish them from the embodiment described above.

In this description, identical numerical references, optionally assigned a "prime" or a "second", identify elements or organs identical or similar to those of the first embodiment.

The safety casing 10 of the second embodiment shown in FIG. 8 comprises a locking ring 14 ′ mounted for rotation around the axis X of this casing, in a predetermined axial position, on the inner side wall of the casing.

This rotating assembly of the ring 14 ′ can be carried out using lugs projecting radially outwardly from this ring and passing through slots in an arc of a circle formed in the casing 10, as shown schematically at 271, 272. in FIG. 8, so as to allow rotation of the ring 14 'on the casing 10, with an amplitude of approximately 900, for example.

From the inner wall of the ring 14 ′ protrudes at least one and, preferably, two diametrically opposed studs 281, 282 each constituting a cam cooperating with an associated follower 291, 292 respectively, formed on the sleeve 7 and described below. below in conjunction with Figures 9A to 9D.

plan axial passant par les cames 281, 282, et une représentation schématique de la position de la came 281, par exemple, au long de la contre-came 291 formée dans le fourreau, ces figures illustrant quatre états du dispositif suivant l'invention. La seringue destinée à être accueillie In each of these figures there is, in vertical alignment, a sectional view of the casing 10, of the ring 14 ′ and of the part of the sleeve 7 which cooperates therewith, by a

axial plane passing through the cams 281, 282, and a schematic representation of the position of the cam 281, for example, along the follower 291 formed in the sleeve, these figures illustrating four states of the device according to the invention. The syringe intended to be received

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by this device is not shown for clarity of the drawing.

291 (et la contre-came 292, non représentée mais identique) prend la forme générale d'un"V"se développant au long de la paroi cylindrique du fourreau traversée par la came 281. In Figures 9A to 9D it appears that the follower

291 (and the follower 292, not shown but identical) takes the general shape of a "V" developing along the cylindrical wall of the sleeve through which the cam 281 passes.

The two cams 291, 292 are diametrically opposed on the sleeve 7.

In the first position of the housing 10 shown in FIG. 9A, that is to say that in which it surrounds and protects the needle (not shown), the spring 13 maintains the housing 10 in a first axial position defined by the contact of the cam 281 with one end of the follower 291. In this position, the end of the casing 10 can be applied against the skin of a patient.

Pressure of the syringe on this skin, in the direction of arrow f2 (figure 9B) turns the ring 14 'on the sheath 7 due to the curved shape of the branch of the follower on which the cam then slides. 281. The ring then reaches a point of the follower where the profile of the latter presents a cusp. In this second position of the casing 10, the needle (not shown) of the syringe protrudes from the casing and passes under the skin 23 of the patient on which the syringe is pressed. The drug is then injected.

After withdrawal of the syringe, the casing 10 is free to return to its first position (see FIG. 9C) under the action of the spring 13, due to the fact that the profile of the counter-cam is then parallel to the axis X. At the end of stroke the cam 281 is driven, by a curvature of the profile of the counter-cam, in one end thereof which is shaped to trap it with respect to axial movements, as shown in FIG. 9D. The housing 10 being integral with the cam 281 can then no longer leave its second position, that is to say that in which it protects the needle, after a

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single use of the syringe. Stops such as those referenced 121 prevent tearing of the housing, as in the embodiment of Figures 1 to 7C.

There is shown in Figures 10 to 13 respectively, the housing 10, the spring 13, a ring 14 "and the sleeve 7 forming part of a third embodiment of the device according to the invention, these parts being shown spaced apart on the same X axis along which they are assembled.

The housing 10 differs from that of the embodiment of Figure 1 in that its side wall is cut out of at least one, and preferably two, diametrically opposed cams 301, 302, designed to be traversed by cams in the form of diametrically opposed studs 311, 312 on the outer surface of the ring 14 ". In FIGS. 10 and 12 only the follower 301 and the cam 311 are visible, respectively.

The cams 301, 302 are of identical shape, asymmetric Y, having two branches parallel to the X axis, one (301a) of the branches being shorter than the other (301b), the axial ends of which are more close to the axial ends of the casing 10 than those of the branch 3 01a.

The safety housing 10 is further distinguished from that of the embodiment of Figures 1 to 7C in that it internally comprises two diametrically opposed cam surfaces 321, 322 arranged to cooperate with corresponding cam surfaces 331, 332, respectively, formed at the ends of two fingers projecting axially, in diametrically opposed positions, from the ring 14 "(see figure 12). These cam surfaces are inclined on the X axis so that when the surfaces 321, 322 come into contact with the surfaces 331, 332, the ring 14 "is subjected to a torque which sets it in rotation about the axis X, this rotation being controlled by the counter-cams 301, 302.

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After assembly of the parts 10, 13, 14 "and 7, these constitute the active part of the device according to the invention, shown in three different states in FIGS. 14A to 14C.

In FIG. 14A, the housing 10 is in its first position, out of any pressurized contact with the skin of a patient, for example. In this position, the cam 311 retains the casing 10 in a position where it is sufficiently depressed on the sleeve 7 to then pass over two pawls 341, 342 formed in the outer wall of the sleeve in two diametrically opposed positions (see section of the FIG. 15A, according to the section line A of FIG. 14A), retaining them in an inactive position, where they do not oppose an axial displacement of the housing 10.

In FIG. 14B, this casing is pressurized against the skin 23 of a patient in order to inject the medicament contained in the syringe (not shown) installed in the safety device according to the invention. The pawls, still inactive, do not oppose the depression of the casing 10 on the sheath 7, up to its second position in which the needle of the syringe leaves the casing to pass under the skin 23 of the patient.

After removing the needle (Figure 14C), the cam 311 being in the branch 301b of the follower 301, branch parallel to the X axis, the housing can go up under the thrust of the spring 13 until the cam 311 abuts on one end of this branch, closer to the corresponding end of the casing than is the corresponding end of the branch 301a (see FIG. 10). As a result, the casing can go up on the sleeve up to the axial position which releases the pawls 341, 342 (see FIG. 15B, section along the line A in FIG. 14C), the latter then being able to engage in notches 351. ,

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352 opposite the outer wall of the sheath 7. This engagement allows the pawls to oppose any movement of the housing 10 which could disengage the needle from the syringe, just as in the other two embodiments of the present invention.

Of course, the invention is not limited to the embodiments described and shown which have been given only by way of example. Thus, other "anti-return" blocking means could be used, instead of those described above.

Likewise, the invention extends to devices designed to equip syringes provided with means making it possible to prevent an involuntary or unauthorized actuation of the rod / piston assembly, or of cores replacing this assembly or also of means of adjustment of the stroke of the rod, etc., etc. It also extends, of course, to the equipment of syringes designed to inject products other than drugs into bodies other than the human or animal body.

Claims (11)

1. Safety device for a disposable syringe equipped with a needle (4) for injecting parenteral medication, characterized in that it comprises: a) a safety casing (10) movable along the axis ( X) of said syringe between first and second positions in which said housing (10) protects and disengages, respectively, the free end of said needle (4), said housing (10) being loaded by a spring (13) towards its first position, and b) means (14,26; 14 ', 2911 292; 14 ", 341, 342) for locking said housing (10) in said first position when the housing (10) returns to this position under the action of said spring (13), after a first passage of the housing (10) from its first to its second position. 2. Device according to claim 1, characterized in that it comprises a substantially cylindrical sheath (7) designed to coaxially receive the syringe in an irremovable manner, said safety casing (10) being slidably mounted on said sheath (7) . 3. Device according to claim 2, characterized in that said locking means comprise a ring (14) of flexible material mounted coaxially on said protective casing (10) so that said casing (10) passing from its first to its second position, said ring (14) is pushed from an initial position to a final position in which it is integral with said housing (10) and said sleeve (7), respectively, said ring (14) expanding radially in said casing (10) when the latter returns from its second to its first position, to then abut on an internal circular shoulder (26) of said casing (10) by blocking any return of the casing (10) to its second position. 4. Device according to claim 3, characterized in that said ring (14) comprises a <Desc / Clms Page number 16> plurality of elastic tabs (15i) projecting radially outward from one of its bases and a circular rim (16) projecting inwardly from the other of its bases to snap into at least one complementary notch (241, 242) formed in the outer wall of said sheath (7) when said safety casing (10) moves from its first to its second position. 5. Device according to claim 2, characterized in that said locking means comprise a ring (14 ') rotatably mounted on said housing (10), inside and in a predetermined axial position thereon, at the at least one cam (281, 282) projecting internally from said ring (14 ') to cooperate with a follower cam (291, 292) formed in the side wall of said sleeve (7), said follower cam (291, 292) being profiled so that said casing (10) passing successively from its first to its second position to finally return to the

first, said cam (281, 282) finally reaches an end of said follower (291, 292) shaped to oppose an axial return of said cam (281, 282), and of the housing (10) on which it is mounted in the second position of said housing (10). 6. Device according to claim 2, characterized in that said locking means comprise a ring (14 ") rotatably mounted on said sleeve (7) and provided with at least one cam (311, 312) cooperating with a counter -came (301, 302) formed in the wall of said protective casing (10), and at least one pawl (341, 342) formed in the sleeve (7), said follower (301, 302) being profiled so that the housing (10) retains said pawl (341, 342) in an inactive position until it returns to its first position, a position beyond which it is then pushed by said spring (13) to release the pawl (341, 342) which then engages in a notch (351, <Desc / Clms Page number 17> 352) of said housing (10) so as to prevent any return thereof to its second position. 7. Device according to claim 6, characterized in that it comprises means (321, 322, 331, 332) distributed between said ring (14 ") and the inner wall of said housing (10), to force the ring ( 14 ") in rotation when said housing (10) is pushed from its first to its second position. 8. Device according to any one of claims 2 to 7 characterized in that said locking means further comprise stop means (him, 112) to prevent said housing (10) from escaping from said sheath (7) , under the thrust of said spring (13), from its first position. 9. Device according to any one of claims 2 to 8, characterized in that it further comprises a protective cover (17) designed to be removably and coaxially mounted on the casing (10) of safety. 10. Device according to claim 9, characterized in that said cover (17) comprises gripping means (19) of a finger (5) for protecting the needle (4) of the syringe, suitable for allowing the simultaneous extraction of the cover (17) and of said finger (5), before the execution of an injection. 11. Device according to any one of claims 1 to 10, characterized in that it constitutes a set of preassembled parts, ready to receive a commercial syringe to be secured, designed for single use.