Pin head structure of Safety Syringe

A needle head structure of a safety syringe, comprising:

• a protecting cover, having an opening formed at an end of the cover ;
• a first sleeve, being a tubular body with an opening formed at both ends of the first sleeve separately and a containing portion formed therein, the containing portion containing a guide portion, a groove and a latch portion formed therein and provided for passing through a corresponding second sleeve;
• a second sleeve, being a tubular body with an opening formed at both ends of the first sleeve separately and a containing portion formed therein, the containing portion containing a guide portion, a groove and a latch portion formed therein;
• wherein an embedding protrusion being formed at an end of the second sleeve and passing through the syringe holder and the first sleeve;
• a syringe holder, being a tubular holder, configured to correspond to the protecting cover, having a containing portion disposed at an end of the syringe holder, and a syringe body disposed at another end of the syringe holder, and a positioning portion and a latch plate being formed and enclosed by the syringe holder for passing through the corresponding second sleeve;
• and
• a plunger, including an injecting portion, a diversion hole and a diversion portion;
• wherein the first sleeve, the second sleeve and the syringe holder are structures having corresponding latched embedding protrusion and latch portion, so that the first and second sleeves are fixed between the syringe holders, and the plunger includes a guide channel for reducing a liquid remained in the plunger, so that the first sleeve is pulled towards an end to link the second sleeve after use, and the first sleeve is latched to an end of the second sleeve, and the other end of the second sleeve is latched between the syringe holders, so as to completely cover and protect the syringe body and reduce the risk of being pierced by the needle head structure.