OA10371A - Destructible syringe with retractable needle - Google Patents

Abstract

A disposable syringe having a retractable needle and a spring (17) for automatically withdrawing the plunger (1) from the barrel after injection, wherein plunger-locking projections (19) prevent the plunger from being reinserted into the sleeve. The projections pierce the plunger automatically when excessive force is exerted thereon, whereby the plunger (1) is damaged and the syringe is rendered useless.

Description

1 010371

The invention relates to a syringe with removable needle, in particular intended to prevent the reuse of the syringe after a first use.

US Pat. No. 5,267,976 discloses such a syringe. It comprises a body carrying at an end of the injection needle support means, a piston movable in said body, a protective sleeve inside which is slidable said body, a spring disposed between the sleeve and the body. locking of the sheath on the body comprises first and second shoulders of the same direction on the outer wall of the body and at least one first lug carried by a portion integral with the sheath, that is to say the sheath itself or for example a sleeve that is integral. The lug cooperates in abutment with the first shoulder to define a first locking position of the body relative to the sheath in a firstensens, the spring being compressed and the needle out of thefourreau in this first position. The lug also cooperates with the second shoulder to define a second locking position in the same direction, the spring being at least partially disbonded and the needle being returned in the sheath in this second position. The passage from the first position to the second position is effected by the cooperation of the piston with said first flexible knot to release at the end of stroke said piston of the first shoulder shoulder and thus cause under the effect of the spring the retreat of the body in the sleeve until its blocking in second position. The syringe additionally comprises at least a second flexible lug and a third shoulder, in opposite directions respectively to the first lug and to the first two shoulders, respectively positioned on the sheath (or the sleeve) and the wall of the body to block the body in the sheath, when in the second blocking position, in the opposite direction of the first direction.

In the preferred version of this known syringe, there are provided two lugs of each type formed enquadrature in a sleeve secured to the sheath higher sapartie.

This syringe gives overall satisfaction, but it may happen that if we try to réenfoncerabsolument the body in the sleeve after use, against the locking lugs, they can dry and get caught between the body and the sheath, now thus inadvertently the needle in position partially left. The object of the present invention is to provide new improvements to a safety device of the above type which further enhances its reliability and safety.

According to a first aspect of the invention, the serin-gue is provided to destroy itself if one tries to force it when it is in its blocking position after use. For this purpose, at least one of the lugs, preferably that of the lugs which prevents the body from being reintroduced into the sheath after use, while abutting against a rim of a groove formed externally in the body, is arranged to pierce the body when the force exerted by the user on the body relative to the sleeve is obviously excessive.In other words, when the force exerted by the lug on said edge exceeds a value considered as normal, the bottom wall of the groove will be pierced by the emot. For this purpose, the bottom wall of the groove is advantageously provided rather thin, which is made possible by forming said groove in the immediate vicinity of

The lower end of the body. As for the spur, it is preferably of sharp or piercing shape: it is formed in bevel or tip, and made in a more hard material than that which constitutes the syringe body. It can be envisaged to associate with the base of at least one integrated or separate reinforcement ergotun, in the form of an over-thickness of the base or against anti-tearing at the base on the side of the obturated angle formed by the arm and the wall.

Advantageously, the body is extended by a skirt of the same diameter at the level of the needle support means.

The lugs are formed in the sleeve and the latter may comprise upstream lugs a remote partguiding the body.

Various frangible zones can be provided on the syringe. Other features or advantages of the invention will become apparent from the following description of a preferred embodiment.

Reference is made to the accompanying drawings in which: - Figure 1 is a longitudinal sectional view of the syringe in puncture position, the section beingfaet in the diametral plane passing through the secondgots; Figure 2 is an analogous longitudinal sectional view in the diametral plane perpen-dicular to the previous, passing through the first lugs; FIG. 3 is a sectional view of the syringe in the retracted position, in the same plane as FIG. FIG. 4 is a partial analogous view in the same plane as FIG. 2; - Figure 5 is a detail view of a lug in section; Figure 6 is a view of another embodiment of the lug.

Figures 1 to 4 show a serin-gue assembly consisting of a substantially cylindrical body lcomportant an open end and a partially-closed end or bottom.

Holding at the bottom is formed a tip 5 comprising a frustoconical part fixing pin of a needle-the classic not shown truncated conical attachment end. The tip 5 is pierced with a bore 8 communicating the interior of the body with the bore of 1'ïiguille.

Through the open end of the body 1, a piston 13 with a cruciform stem 11 (or only three fins, so as to save the material) and a pusher 12 sliding freely inside the body 1 can penetrate into the body 1. A bulge 42 connected to the pusher 12 and thus to the piston, is formed by a disc of diameter slightly greater than the outside diameter of the body 1.

A substantially cylindrical sleeve 14 is mounted on the body 1. At one of its ends, saparoi narrows to form a hole sufficient for the passage of the pin 5 for fixing the needle, and whose contour may serve to support a spring of compres-sion 17 whose other end is supported on a shoulderbody1, at its end. The spring 17 is maintained during its compression around the body, possibly with the aid of fins 4.

A substantially cylindrical sleeve 40 is made integral with the sleeve 14 at its upper end anywhere appropriate means, for example by gluing or welding two opposite flanges 41, 43 formed at the respective edges of the sleeve 40 and the sleeve 14. The material of the sleeve 40 is advantageously more rigid than that constituting the sheath 14 and the body 1. 5 010371

The sleeve 40 carries the support collar 18 of the syringe.

The opposite lugs 19 and 20 are provided qua-drature inside said sleeve 40 and may be made in one piece therewith, for example by molding. The two lugs 19 are directed downwards and are likely to cooperate with a first shoulder 21 of the body 1 formed by the edge of a groove 43 disposed outside its upper edge to effec-kill a first blocking of the body 1 in the sleeve 14, in the position of Figures 1 and 2 corresponding to the arming of the syringe, where the spring 17 is compressed.Les same pins 19 are likely to deviate underleaction of the disk 42 when the The spring 17 then relaxes and pushes and moves the sleeve 14 away from the body 1 to the second locking position in which the lugs 19 cooperate with a second peripheral shoulder 23 (position shown in FIGS. and 4) located at the base of the body 1, and constituted by the lower edge of a groove 45processed in said body.

The lugs 19 and the shoulder 23 thus prevent the body 1 and its needle from being withdrawn from the sheath 14 which it then covers.

The second lugs 20, acting in opposite directions of pins 19, are intended to prohibit a new output of the needle 6 out of the sheath. For this purpose, the notches 20 cooperate (see FIG. 3) with a third shoulder 24 (in the opposite direction to the shoulders 21 and 23) constituted by the upper edge of the groove 45. Thus, after the injection, the body 1 remains locked, both forwards and backwards, in the positionrepresented in FIG. 3 and the needle is inaccessible.Naturally, the piston 13, quite conventional, can be removed from the body 1. 6 010371

The width of the shoulders 23 and 24, that is to say the depth of the groove 45, is advantageously the same as that of the shoulder 21.

In accordance with the invention, the lugs 20 and optionally the lugs 19 are arranged to thrasp the wall of the body 1 when they are subjected to excessive force against the shoulder with which they cooperate, reflecting an attempt to recover the needle. To this end, the lug terminates advantageously bevel or tip with two rectangular sides or four triangular sides 46 (Figure 5), which allows it to pierce the thinned wall of the body 1 to level the groove 45 forming the shoulders 23 , 24.

Although the pins are already formed in the plastic of the sleeve 40, more rigid than that of the body 1, one can further increase their rigidity by providing their attachment to the sleeve 40 an extra thickness 46 (Figure 5).

More advantageously, in order not to interfere with the flexibility that the ergot must keep in one direction, the er-taste is expected to be fairly thin (FIG. 6) and comprises, adja-cent at its base and above it. a short rigid support on which the ergot can be applied when it is pushed upwards and which prevents the tearing of the ergot.

The material constituting the lug is a material with good shape memory, because it must be able to retain elasticity during the mean storage time of the syringes (3 to 5 years).

The groove 45 forming the two recesses 23, 24is arranged as low as possible on the desering body, to be near the base of the body 1.This allows to provide a relatively deep groove, leaving a thin bottom wall, easy to pierce 7 010371 by the lugs 19 and / or 20. This groove may create a zone of weakness, especially during injection molding: in order to ensure a correct filling of the mold beyond the groove, it is preferable that the in-jection is make at the lower part of the body 1, near said groove.

Another advantage of the low position of the yarn 45 is that the stroke of the needle is thus as long as possible.

Therefore, for the same strength of the spring, we can use a thinner wire and increase the number ofpires.

Moreover, the force required for the spring does not need to be very high insofar as the traps 19 and 20, during the transition from the stitching position to the retracted position, rub on the outside surface of the body without being there. exert considerable force, since the lugs are not strongly compressed.

As arranging the groove 45 very low body l makes the body 1 more out of the sleeve 14dans the second locking position of the syringe, lessen the length of insertion of the body in the sheath can create a risk of misalignment between the body and the scabbard ; it may be useful to extend the lower part of the body 1 by a cylindrical skirt sketched 48 in Figure 4, the spring 17 being housed between said skirt 48 and the nozzle 5. The diameter of the skirt 48 iscelui of the body, and therefore contributes to improve leguidage.

This guidance can also be improved by providing that the sleeve 40 comprises a body guide perimeter 1, placed upstream of the lugs 19, 20 at a sufficiently large distance to ensure this guidance.

This guiding perimeter is advantageously formed by the smaller diameter portion 49 of a diabolo shape 50 provided upstream of the sleeve 40. The flared inlet of the diabolo 50 further facilitates the introduction of the syringe plunger1. when setting up initially.

Various frangible zones can be planned to oppose further attempts at reunification. Such frangible zones are advantageously provided on the flanges 18 of the sleeve and / or on the plunger of the piston, for example at a restriction 51 (FIG. 1).

In order to avoid inadvertent activation of the syringe during pre-injection manipulations (for example necessary when mixing various products in the syringe), a detachable safety pin can be provided under the bulge 42, preventing, as long as it is not removed, the bulge42 to reach the level of the lugs 19 and thus to trigger the recovery of the body 1. 15

Claims (9)

R \ ι - λ ^ Vosto & · .. 9 010371 CLAIMS 1. A self-retracting needle syringe, comprisinga body (1) carrying at one end means (5) of the injection needle support, a piston (13) mobiledin said body, a sheath (14) protector inside whereof the body (1) is slidable, a spring (17) disposed between the sleeve (14) and the body (1), means for locking the sleeve (14) on the body (1) comprising a first and a second shoulders of the same direction (21, 23) on the outer wall of the body (1) and at least one first lug (19) flexible carried by a portion integral with the sleeve (14) so as to cooperate abutting with the first shoulder (21) for defining a first locking position of the body (1) relative to the trough (14) in a first direction, the spring (17) being compressed and the needle (6) exiting the sheath in this first position, and with the second shoulder (23) for defining a second locking position in the same, the spring (17) being at least partially eelydanded and the needle (6) being retracted into the sheath (14) in this second position, the passage from the first position to the second position being bycoooperation of the piston (13) with said first lug (19) for release at the end of stroke of said piston (13) the lug (19) of the first shoulder (21) and cause therebyi under the effect of the spring (17) recoil of the body (1) in the sleeve (14) to its blocking in secondposition, the syringe further comprising at least one second flexible lug (20) and a third shoulder (24), opposite direction respectively to the first lug (19) and the first two shoulders (21, 23), positioned respectively on a part integral with the sleeve (14) and the wall of the body (1) to block the body (1) in the When it is in the second locking position, in the opposite direction to the first direction, at least one of the second and third shoulders (23, 24) being formed by the edge of a groove formed in the body (l), characterized in that at least one of the two lugs (19,20), which cooperates with said border for the purpose of blocking the body (1) in the sheath (14) is arranged to pierce the body (l) when the force exerted by said lug on said border exceeds a value considered edemale. 2. Syringe according to claim 1, characterized in that the piercing pin is formed in bevel or enpointe. 3. Syringe according to any one of the preceding claims-tions, characterized in that said grooveis formed in the immediate vicinity of the lower end of the body (1). 4. Syringe according to any one of the preceding claims-tions, characterized in that the body (1) isprolonge by a skirt (48) of the same diameter at themeans (5) of the needle holder. 5. Syringe according to any one of the preceding claims-tions, characterized in that the lugs (19,20) are formed in a sleeve (40) secured to thefourreau (14) at its upper part. 6. Syringe according to claim 5, characterized in that the sleeve (40) is made of a more resistant material than the body (1). 7. A syringe according to any one of claims-5 or 6, characterized in that the sleeve (40) has upstream lugs a remote portion (49) deguidage of the body (1). 11 010371 8. Syringe according to any one of the preceding claims-tions, characterized in that it comprises frangible zones. 9. A syringe according to any one of revendica-5 previous tions, characterized in that at least one lug (19) is associated with its base to an integral reinforcement or separate, in the form of extra thickness (46) or against -support (47).