A needle retractable safety self-destruct syringe with replaceable needle

Abstract

A needle retractable-type safe self-destructing syringe comprising a barrel body (1). An inner needle base body (3) is arranged within a barrel neck (2) at an end part of the barrel body (1). The barrel neck (2) and the inner needle base body (3) match with each other and form therebetween a flexible cushioning stopper engaging mechanism. An asymmetric retracting-locking piece having a flexibility feature is arranged at an end part of a syringe plunger (5). The asymmetric retracting-locking piece is a plastic barb body (12) and is formed with the plunger (8) in a single mold-forming. The asymmetric structure and the flexibility feature implement engagement with and locking onto an inner sleeve-type retracting-locking component (4) in a cavity of a needle base. In a stress environment of an asymmetric force, the needle base deflects to a side after being retracted into the barrel body (1), while an injection needle therefore swings in the direction of a nearly 45 degree angle towards a side of the inner wall of the barrel body (1) and is locked by the barrel neck (2). This prevents the injection needle and the needle base from being pushed out of the barrel neck (2) again, thus effectively preventing secondary injury and implementing safe self-destruction of the syringe.

Description

technical field [0001] The invention relates to the technical field of medical devices, in particular to a needle retractable safety self-destruct syringe with exchangeable needles, and in particular to its mechanical connection structure. Background technique [0002] Comparative document 1, patent number: ZL200710047077.4, application date: 2007.10.16, announcement number: CN101411908, patentee: Shanghai Toptop Biochemical Technology Co., Ltd. This case discloses "a safe self-destructing vaccine syringe", including Cylinder, a core rod is arranged in the cylinder, a rubber plug is provided near the end of the core rod, a needle is provided in the neck of the cylinder, and a needle tube is provided at the needle, and the feature is that: the rod body side of the end of the core rod The wall is provided with a transverse notch, and the transverse notch communicates with the longitudinal notch at the rod body at the end of the core rod, and the transverse notch matches the lo...

AI Technical Summary

Problems solved by technology

The metal parts need to be processed and matched or assembled with the core rod. The manufacturing process is complex, difficult and not stable. uncertainties

The existing plastic barbs still have defects or imperfections in structure, thus causing potential safety hazards or safety loopholes in the use of the product

Although the existing plastic buckle design can realize the function of pulling back the needle, in use, the needle is still on the normal track after being pulled back, and the needle may be pushed out again, causing the risk of secondary injury to the user

[0005] In addition, the same problem exists in the existing single-seat retractable safety self-destruct syringes or safety syringes, which is how to solve the problem of stable engagement between the inner needle seat and the barrel and achieve a certain strength to meet the stability requirements; At the same time, the pulling force required when withdrawing the needle seat should not be too large for ease of use

Although the rigid fitting structure can achieve a stable locking effect between the inner needle seat and the inner wall of the cylinder, it is difficult or even impossible to meet the needs of convenient use at the same time

The instability of the plastic material itself and its susceptibility to environmental temperature changes will lead to extremely poor product stability of the hard-fit structure. It is difficult to control the quality and precision during the production process, and it is almost impossible to achieve mass production.

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