Combination needle shield/needle guard device for a hypodermic syringe with a permanently attached needle

A combination needle shield/needle guard device which is positively locked onto a hypodermic syringe with a permanently attached needle;

• said hypodermic syringe comprised of a syringe barrel with needle hub which is an integral part of front end of said syringe barrel;
• said hypodermic needle permanently attached to said needle hub on front end of said syringe barrel;
• said hypodermic syringe comprised of said syringe barrel with piston, said piston sliding inside said syringe barrel, providing means to force liquid medicament inside said syringe barrel through opening of said needle;
• said needle shield/needle guard device comprising a hollow cylindrical housing which is sealed at its proximal end on weakend annular zone with an integral pull-off tab, said cylindrical housing with an internal protrusion located on distal inner wall of said cylindrical housing;
• means for positive locking of said needle shield/needle guard device onto groove system on front end of said syringe barrel, said means preventing forward, backward and counterclockwise rotation of said needle shield/needle guard device in relation to front end of said syringe barrel;
• means for said needle shield/needle guard device as needle shield to enclose said sterile needle which is permanently attached to said needle hub of said hypodermic syringe barrel;
• means for aperture formation on proximal end of said needle shield/needle guard device;
• means to prevent direct retraction of said cylindrical housing from extended lock position to retracted lock position;
• means for said cylindrical housing of needle shield/needle guard device as said needle guard which can retract in relation to said syringe barrel, such that said cylindrical housing with said aperture can be moved from said extended lock position to said retracted lock position, uncovering said needle with said cylindrical housing;
• means for said cylindrical housing of needle shield/needle guard device as said needle guard which can extend in relation to said syringe barrel, such that said cylindrical housing can be moved from said retracted lock position to said extended lock position, re-covering said needle with said cylindrical housing from behind the needle point of said needle;
• means for said cylindrical housing as said needle guard to retract and extend ad-finitum in relation to said syringe barrel;
• means for visibility of volumetric calibrations on said syringe barrel when said cylindrical housing has moved intos aid retracted lock position on said syringe barrel.