SAFE MEDICAL SYRINGE Russian patent published in 2011 - IPC A61M5/315 A61M5/50 

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment, particularly concerns an automatically retractable safe medical piston group syringe which can be manipulated by one hand and which after being used provides needle retraction in its case. The safe medical syringe consists of a needle-holder coupled with a needle, a hollow cylinder for placing the needle-holder after the safe medical syringe completed an injection process and the needle-holder directed when retracted in the hollow cylinder and the piston group located in the hollow cylinder. The piston group consists of a ring joint of a retractable piston and a hollow bushing to form thereby an area of the ring joint with the retractable piston. On an external lateral wall of the retractable piston, there is at least one flange in the area of the ring joint for appropriate tight fit at least in one hollow formed on an internal lateral wall of the hollow bushing. The retractable piston has at least one tension adjustment profile to ensure one tension adjustment profile becoming deformed when an operator continues applying force to a piston group after the injection process completed, and thereby releasing at least one flange from at least one hollow thereby making the retractable piston to be retracted in the hollow bushing. In the second version of the syringe, at least one tension adjustment profile is located on the hollow bushing. The piston group for medical injection consists of the retractable piston and hollow bushing with the ring joint thereby forming a section of the ring joint of the retractable piston. On an external lateral wall of the retractable piston, there is at least one flange in the area of the ring joint for appropriate tight fit at least in one hollow formed on an internal lateral wall of the hollow bushing. Thus, when the operator continues applying force to the piston group after the injection process completed, at least one flange appears from at least one hollow thereby making at least a part of the retractable piston to be retracted in the hollow bushing. In the other version of the safe syringe, the front portion of the hollow cylinder is located nearby the needle-holder and makes integral with a narrow portion of the cylinder having a diametre less than that of the hollow cylinder. The hollow cylinder has a hole which is connected with the narrow portion of the cylinder and which comprises at least one stopper inhibiting falling through of the needle-holder and directing the needle-holder retraction after the injection process completed. In the last version of the syringe, the front portion of the hollow cylinder is located nearby the needle-holder and makes integral with a narrow portion of the cylinder having a diametre less than that of the hollow cylinder. The hollow cylinder has the hole which is connected with the narrow portion of the cylinder and makes integral with at least one bottleneck to inhibit for falling through of the needle-holder and to direct the needle-holder retraction after the injection process completed.

EFFECT: invention provides easy one-hand manipulation, eliminates damages caused by inappropriate operating angle or operator's position during injection process, eliminates assembly related damages, has higher quality, high transmission coefficient and reliability combined with reduced raw materials consumption and conversion costs.

15 cl, 14 dwg