Syringe

Abstract

The invention provides a syringe, which comprises a needle cylinder comprising a needle head mounting cavity and a core rod mounting cavity, wherein the cross sectional area of the needle head mounting cavity is smaller than that of the core rod mounting cavity; a pull-back piece installed in the needle head mounting cavity, wherein the needle head is installed on the pull-back piece, and a cavityis formed in the end, close to the core rod mounting cavity, of the pull-back piece; a core rod arranged in the core rod mounting cavity and capable of moving between a push-out position and a returnposition, wherein the head of the core rod enters the cavity of the pull-back piece at the push-out position and is clamped in the cavity of the pull-back piece; a bias pressure structure arranged inthe cavity of the pull-back piece and / or the head of the core rod, wherein the head of the core rod applies bias pressure to the pull-back piece through the bias pressure structure, and when the headof the core rod moves to the retreating position, the bias pressure structure enables the pull-back piece and the needle head to incline deviating from the axis of the needle cylinder in the core rodmounting cavity through the bias pressure. After the syringe is used, the core rod is pulled back, the pull-back piece deflects in the needle cylinder, the needle head deflects along with the pull-back piece and cannot be pushed out of the needle cylinder again, and use is safer.

Description

technical field

[0001] The invention relates to the technical field of medical instruments, in particular to a syringe. Background technique

[0002] Syringe is a common and widely used medical device, mainly used for liquid medicine or blood test. In recent years, in order to avoid repeated use and cross-infection, the use of disposable sterile syringes has been promoted. However, the existing single-use sterile syringes remain intact after they are used up and can be reused, which gives opportunities to some criminals, brings the hidden danger of cross-infection, and easily causes disease transmission.

[0003] In the prior art, there is a pull-back self-destructing syringe, which includes a needle, a needle seat, a syringe barrel and a push rod. A rubber plug is installed at the lower part of the rod, the lower end of the push rod is provided with a barb fixing part which passes through the rubber plug, a spring barb with an upward opening is fixed on the barb fixing pa...

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