Piston for injector

A technology for syringes and pistons, which is applied in the field of pistons for medical syringes. It can solve the problems of reduced contact area between the sealing ring and the syringe sleeve, and reduced sealing performance, so as to avoid the reduction of sealing performance, prevent blood return, and enhance the use safety.

CN103656804AInactive Publication Date: 2014-03-26SHANDONG WEIGAO GROUP MEDICAL POLYMER
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2014-03-26
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a piston for an injector. The piston for the injector comprises a piston top part and a piston body, wherein the piston body is a hollow cylinder with an opening in the bottom; the lower part of the hollow cylinder is connected with a push rod of the injector; the upper part of the hollow cylinder and the piston top part form a piston contraction cavity; a sealing ring is arranged on the outer part of the piston body; the piston top part is of a conical structure with a thin wall; and the tail end of the conical surface of the piston top part and the upper edge of the sealing ring on the top part of the piston body form an annular plane boss. Due to the plane boss and the piston contraction cavity structure on the top part of the piston, the sealing performance and the blood return preventing performance of the injector can be improved, and the safety in use is enhanced.
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Description

technical field

[0001] The invention relates to a piston, in particular to a piston for a medical syringe. Background technique

[0002] At present, the syringes used clinically at home and abroad are composed of an outer cylinder, a push rod, and a piston. The purpose of pumping liquid is realized by pushing and pulling the piston through the push rod, and the function of the syringe is realized. The piston structure is closely related to the sealing performance and anti-bleeding performance of the syringe. Chinese invention patent application CN103170035A, a pre-filled syringe with anti-bleeding type. There is a piston contraction chamber between the top of the piston and the push rod. The top of the piston is a thin-walled structure. The top of the piston is deformed to prevent the top of the piston from entering the hollow channel. Avoid bleeding. But the top of this piston and the sealing ring of piston body top have adopted the tangential structure. When the top of ...

Examples

Embodiment Construction

[0012] Such as Figure 1-Figure 3 As shown, a piston for a syringe includes a piston top 1 and a piston body 2. The piston body 2 is a hollow cylinder with an open bottom. The piston shrinkage cavity 21 is formed, and a seal ring is provided outside the piston body. As a preferred method, three seal rings are provided on the outer surface of the piston body. Ring 25, the second seal ring 24 is located between the first seal ring 25 and the third seal ring 23, the distance between the first seal ring 23 and the top seal ring 25 of the piston body is 1 / 2-3 / 4, the piston body 2 is a hollow cylinder There is a piston thread 22 inside the body, and the piston thread 22 connects the piston body 2 to the syringe push rod. The top of the piston 1 is a thin-walled conical structure. An annular plane boss 26 .