US Patent 10022505 Safety pen needle

A safety insulin pen needle, including a needle hub, a needle tube assembly base arranged on the needle hub, a needle tube, a trigger protector arranged outside the needle hub and a spring arranged between the trigger protector and the needle hub. A guide groove with a special structure is arranged on the side wall of the trigger protector, and a clamping column corresponding to the guide groove is arranged on the outer edge of the side wall of the needle hub, so that the trigger protector is in a to-be-triggered state before use, and is triggered only when in use. Thus, an injection needle can be protected from being exposed to the outside after use, and cross-infection caused by mistakenly touching or reusing is avoided.