self-destructing syringe

Abstract

The invention discloses a self-destructing syringe which improves the needle base itself and its position-limiting design with the outer sleeve so that the anti-retraction force can be maintained for a long time. It includes an outer sleeve, a core rod, a piston and a needle base assembly. The guide cone head of the tapered shaft shoulder, the needle seat assembly is assembled by the upper needle seat and the lower needle seat, the front part of the upper needle seat is the connection part of the puncture needle, and the rear part of the upper needle seat is connected with the lower needle seat through the combination of the tapered surface The inner cone at the front fits, and the outer convex rib at the rear end of the outer cone is correspondingly limited by the inner rib at the rear end of the inner cone on the lower needle holder. A limit fit structure corresponding to the corresponding structure of the inner wall of the jacket is provided. The rear part of the lower needle seat is provided with an inner stop that matches the tapered shoulder. When the core rod is retracted until the tapered shoulder contacts the inner stop, the outer There is also an interval between the convex ribs and the inner convex ribs, thereby maintaining the anti-retraction force of the needle tip of the syringe, maintaining good sliding properties when the syringe sucks the liquid medicine, and reducing the pulling force required for shrinking the needle and destroying its shape.

Description

technical field [0001] The invention relates to a syringe, in particular to a self-destructing syringe which can be destroyed by pulling a needle seat back into a casing through a core rod. Background technique [0002] With the continuous promotion of safe injection, self-destructing syringes with self-destructing function have been widely used in clinical practice. At present, self-destructing syringes with retractable puncture needles have become the mainstream of self-destructing syringes because they can effectively protect medical staff and prevent accidental injuries. [0003] On July 11, 2012, the Chinese invention patent No. CN102553036A, "Secondary Separated Safety Self-Destructing Syringe", is assembled into a separate needle seat with a locking cone head and a connecting seat, and the first and second needle seats are respectively set on it. Two non-return structures, and correspondingly the first and second deforming structures are arranged at the axial interva...

AI Technical Summary

Problems solved by technology

[0004] However, there is still a need for improvement in the needle seat design of the existing secondary separation type safety self-destructing syringe

The reason is that the connection between the needle seat and the jacket is limited by partial interference fit, and once the plastic material is aged and deformed, the tension at the interference fit will gradually decrease, and the anti-retraction force index will decrease during injection and puncture. , even the anti-retraction force cannot meet the requirements, and the phenomenon of needle withdrawal occurs during injection

Images