Safety type needle syringe

Abstract

A high-safety injector is composed of a barrel body, push rod, needle holder and needle cover, and features that the needle holder can be embedded in the internal conic edge of the reduced neck of barrel body to form an air-tight ring, and the front end of said push rod has a guide slot for discharging the residual liquid medicine from the barrel body.

Description

technical field [0001] The invention relates to a syringe, in particular to a disposable safety syringe. Background technique [0002] In the prior art, the most traditional type of syringe is to be reused after being sterilized after injection. However, if there is a lack of disinfection, it will lead to improper infection; Disposable, that is, a convenient syringe that is only used once. Although this type of syringe can avoid infection due to improper disinfection of traditional syringes, there is no protective treatment for the discarded syringes after use, resulting in discarded syringes. From time to time, things such as stabbing medical staff and cleaning personnel by mistake happen, causing another kind of improper infection and injury. For this reason, many manufacturers have invented safety syringes to improve the aforementioned shortcomings, for example: U.S. Patent No. 5,899,887 (as shown in Figure 1A), 6,033,385 (as shown in Figure 1B), 5,569,203 (as shown in F...

AI Technical Summary

Problems solved by technology

[0003] However, based on the above-mentioned prior patents, the retractable structure of the needle cylinder and the needle holder developed for the traditional needle cylinder structure has the following disadvantages, that is, the combination of the injection needle holder and the needle cylinder needs to be specially considered for the stability of the combination. performance and retractability after use, and the most important thing is the air density after the combination of the needle seat and the syringe, which requires a very high standard

Therefore, in the structural design of the combination, if only the stability and airtightness of the combination are considered, it will be difficult to pull back the needle hub after injection; if only the convenience of pulling back the needle hub is considered, the stability of the combination of the needle hub and Airtightness is bound to be insufficient, so there are practical shortcomings

In addition, the pull-back needle seat type syringe uses a protruding cone in front of the injection push rod to fit the needle seat, and the needle seat is pulled back into the syringe. However, in actual use, when the injection push rod When it is pushed close to the bottom of the syringe, that is, when the tapered edge of the cone touches the bottom of the needle seat, the tapered edge at the front end of the cone will close the liquid medicine injection channel inside the needle seat, so that the bottom of the syringe will be in contact with the cone. A closed space is formed between the bodies, so that the residual medicinal liquid in this space cannot advance through the injection channel, forming a resistance to block the fit of the cone and the needle seat. At this time, a greater thrust is required to fit, but at this time Causes the vibration of the injection, which makes the patient feel uncomfortable, and sometimes even cannot be fitted; for example: US Patent 5569203 (as shown in Figure 1C), there is a disadvantage that the cone cannot be combined with the needle seat due to the resistance of the residual fluid; In addition, U.S. Patent No. 5,899,887 (as shown in Figure 1A) and No. 6,033,385 (as shown in Figure 1B) are designed to improve the shortcomings of the No. 5,569,203 case by designing slots on the periphery of the needle seat and setting a large angle inward on the inner channel. Inclined tabs, but this kind of design is impossible to achieve in the injection molding of plastic materials. Even if it is possible, there is no design between the cone and the tabs to prevent miscombination, and it is very easy to use before injection. When the injection push rod is pushed forward (exclude the air and then pull back to absorb the liquid medicine), it will form a wrong combination, which will cause the disadvantage of pulling the needle seat back before injection, and lose the practical function

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