Limit mechanism of needle holder in retraction type safety syringe

Abstract

The invention provides a limit mechanism of a needle holder in a retraction type safety syringe, belongs to the technical field of medical apparatus and instruments, and solves the problem that the position of needle holder in an existing syringe is unstable. The limit mechanism comprises a first limit unit and a second limit unit, wherein the first limit unit is disposed between the syringe and the needle holder and used for limiting the needle holder from moving upwardly and the second limit unit is disposed between the syringe and the needle holder and used for limiting the needle holder from moving downwardly. A protruding shoulder is disposed on the inner lateral wall of the syringe. The lower side of the protruding shoulder is provided with a limit part which extends downwardly. The second limit unit comprises the limit part and an expansion part located in the syringe, wherein the expansion part is provided with an annular expansion portion, the expansion portion is located between the limit part and the lateral wall of the syringe and abutted against the limit part, and the limit part is bent inwardly and abutted against the needle holder. The limit mechanism has the advantages that the limit part which extends downwardly is disposed on the lateral wall of the syringe, so that the needle holder is stably limited in the syringe under the action of the expansion part.

Description

technical field [0001] The invention belongs to the technical field of medical devices, and relates to a syringe, in particular to a position-limiting mechanism for a needle seat in a retractable safety syringe. Background technique [0002] Currently, syringes are the most commonly used and one of the most used medical devices. In recent years, in order to control iatrogenic infectious diseases and avoid adverse consequences such as cross-infection, disposable sterile syringes have been widely used. However, existing disposable syringes all have defects such as being intact after use, reusable, without any safety device, and exposed after injection. On the one hand, it is easy to be used by malicious elements, and the reuse of discarded disposable syringes after use is very easy to cause the spread of viruses and cross-infection; on the other hand, the needles after injection are still left outside. Not only does it cause inconvenience to the handling and destruction of s...

AI Technical Summary

Problems solved by technology

However, due to the limited wall thickness of the syringe and the shallow depth of the ring groove, the structure is relatively unstable when the seal is stuck on the groove, and the seal is easily detached from the groove, causing the syringe to fail to use normally

Even if a higher protrusion is set on the inner wall of the syringe as a fixation, due to the limitation of the production mold, it cannot be made into a ring-shaped protrusion, but several separate protrusions, which requires that the needle seat and the syringe It is necessary to determine an angle before assembly or manual assembly, and the assembly cost is relatively high

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