Safety assembly for a syringe pre-filled with liquid, in particular a medicine
The syringe (S) comprises a body (K) forming a liquid reservoir, carrying a needle (A) for injecting the liquid, and having a plunger (P) movably mounted in the body (K). The body (K) is housed in a safety sheath ( 1 ) to be axially movable between an active position in which the needle (A) projects through a distal end of the sheath ( 1 ) and a protection position in which the needle (A) is retracted inside the sheath ( 1 ) and towards which position the body (K) is urged resiliently. The body (K) is prevented from moving relative to the sheath in the active position by locking means ( 6 ) that opposite the resilient force on the body, and that are releasable by means ( 8 ) which are activated when the plunger (P) is in an end-of-liquid-injection position.
1. A safety assembly for a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position, the body of the syringe having a proximal end provided with a flange, the assembly further comprising:
a tubular sheath in which the body of the syringe is designed to be housed in axially displaceable manner between an active position in which the needle projects through a distal end of the sheath and a protection position in which the needle is retracted inside the sheath;
resilient return means for urging the body towards its protection position;
locking means for preventing the body from moving relative to the sheath in the active position by opposing the resilient force of the return means;
release means for releasing said locking means when the plunger is in its end-of-injection position;
the locking means comprising two diametrically opposite lugs formed in a wall of the tubular sheath, each lug having a free end provided with a retractable catch;
a cap mounted to slide axially on the sheath between two positions and having a proximal end with a hole for receiving the plunger;
snap-fastening means comprising an internal catch for securing the cap to the tubular body, so that due to retraction of the retractable catches, the cap is moved by resilient return means; and
two complementary shoulders acting as abutments, one on the cap, the other one on the tubular sheath, to limit the stroke of the cap once the locking means have been released, in opposition to the resilient force of the return means.
2. The assembly according to claim 1 , wherein the sheath carries external retention means for being held by the fingers of a user to inject the liquid by moving a drive end of the plunger axially towards the retention means.
3. The assembly according to claim 2 , wherein the retention means of the sheath comprise two substantially diametrically opposite fins or lugs.
4. The assembly according to claim 2 , wherein the retention means comprise a shoulder formed on the outside surface of the sheath.
5. The assembly according to claim 1 , wherein the means for resiliently urging the body of the syringe into the protection position comprise a thrust spring designed to bear against an internal bearing shoulder formed in the sheath.
6. The assembly according to claim 1 , wherein the sheath and the cap are generally in the form of bodies of revolution and have complementary means for preventing relative rotation between each other.
7. The assembly according to claim 6 , wherein the complementary means for preventing relative rotation of the sheath and the cap comprise at least one longitudinal groove formed in the cap and co-operating with a corresponding finger secured to the sheath.
8. The assembly according to claim 6 , wherein the complementary means for preventing relative rotation of the sheath and the cap comprise at least one axial slot formed in the cap and co-operating with a fin.
9. The safety assembly according to claim 1 further comprising an injection device comprising a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position.
10. The safety assembly according to claim 2 further comprising an injection device comprising a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position.
11. The safety assembly according to claim 3 further comprising an injection device comprising a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position.
12. The safety assembly according to claim 4 further comprising an injection device comprising a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position.
13. The safety assembly according to claim 5 further comprising an injection device comprising a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position.
14. The safety assembly according to claim 6 further comprising an injection device comprising a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position.
15. The safety assembly according to claim 7 further comprising an injection device comprising a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position.
16. The safety assembly according to claim 8 further comprising an injection device comprising a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position.
17. A safety assembly for a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position, the body of the syringe having a proximal end provided with a flange, the assembly further comprising:
a tubular sheath in which the body of the syringe is designed to be housed in axially displaceable manner between an active position in which the needle projects through a distal end of the sheath and a protection position in which the needle is retracted inside the sheath;
resilient return means for urging the body towards its protection position;
locking means for preventing the body from moving relative to the sheath in the active position by opposing the resilient force of the return means, said locking means being released by release means when the plunger is in its end-of-injection position;
the locking means comprising two diametrically opposite lugs formed in a wall of the tubular sheath, each lug having a free end provided with a retractable catch;
a cap mounted to slide axially on the sheath between two positions and having a proximal end with a hole for receiving the plunger;
an internal catch for snap-fastening the flange of the tubular body to the cap, so that due to retraction of the retractable catches, the cap is moved by resilient return means; and
two complementary shoulders acting as abutments, one on the cap, the other one on the tubular sheath, to limit the stroke of the cap once the locking means have been released, in opposition to the resilient force of the return means;
wherein the sheath and the cap are generally in the form of bodies of revolution and have complementary means for preventing relative rotation between each other; and
wherein the complementary means for preventing relative rotation of the sheath and the cap comprise at least one longitudinal groove formed in the cap and co-operating with a corresponding finger secured to the sheath.
18. A safety assembly for a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position, the body of the syringe having a proximal end provided with a flange, the assembly further comprising:
a tubular sheath in which the body of the syringe is designed to be housed in axially displaceable manner between an active position in which the needle projects through a distal end of the sheath and a protection position in which the needle is retracted inside the sheath;
resilient return means for urging the body towards its protection position;
locking means for preventing the body from moving relative to the sheath in the active position by opposing the resilient force of the return means, said locking means being released by release means when the plunger is in its end-of-injection position;
the locking means comprising two diametrically opposite lugs formed in a wall of the tubular sheath, each lug having a free end provided with a retractable catch;
a cap mounted to slide axially on the sheath between two positions and having a proximal end with a hole for receiving the plunger;
an internal catch for snap-fastening the flange of the tubular body to the cap, so that due to retraction of the retractable catches, the cap is moved by resilient return means; and
two complementary shoulders acting as abutments, one on the cap, the other one on the tubular sheath, to limit the stroke of the cap once the locking means have been released, in opposition to the resilient force of the return means;
wherein the sheath and the cap are generally in the form of bodies of revolution and have complementary means for preventing relative rotation between each other; and
wherein the complementary means for preventing relative rotation of the sheath and the cap comprise at least one axial slot formed in the cap and co-operating with a fin.
19. The safety assembly according to claim 17 further comprising an injection device comprising a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position.
20. The safety assembly according to claim 18 further comprising an injection device comprising a prefilled syringe for injecting liquid, the syringe comprising a tubular body forming a reservoir for the liquid, carrying a needle for injecting the liquid, and having a plunger mounted in the body to be movable between a ready position and an end-of-injection position.
21. An assembly according to claim 1 , wherein the release means comprises a ramp on the cap.