A protective injection needle comprising a sleeve with a sleeve front, a chamber is formed inside, a pair of blocking slots with a corresponding blocking piece face to face are on the inner center wall, a pair of none-penetrated fastening slots face to face are on the back of the inner wall, a pair of...http://www.google.fr/patents/US20050101918?utm_source=gb-gplus-shareBrevet US20050101918 - Protective injection needle
