SYRINGE WITH RETRACTABLE NEEDLE AND CUTTING CROWN Russian patent published in 2014 - IPC A61M5/32 

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment, namely to syringes with a retractable needle. A syringe comprises a cylinder, a needle assembly, a needle assembly holder at one end of the cylinder, a hollow piston, a cutting crown at the end of the piston and a drive mechanism for the needle assembly retraction into the piston. The needle assembly comprises a needle, an inner space of which is hydraulically connected to the chamber inside the cylinder. The hollow piston is movable inside the cylinder towards the needle assembly. The cutting crown faces the needle assembly and aims at cutting the holder, as the piston advances so that the drive mechanism retracts the needle assembly into the cylinder. The cutting crown profile comprises at least two cutting teeth, which cuts off the first part of the holder, before the other parts of the cutting crown cut off the other parts of the holder; at least two cutting teeth in the gap between the two following cutting teeth along the cutting edge have U-bridges.

EFFECT: using the invention enables providing simplifying the structure, reducing a dead area inside the syringe, cutting the production costs, preventing an air bubble pocket, protecting against the re-use and reducing the holder detachment force applied by the user.

9 cl, 9 dwg