Patent attributes
A safety shield system for a needle cannula of a pen needle injector or similar device, wherein a safety shield may be retracted from a first position enclosing the needle cannula to a second position exposing the needle cannula for injection. The safety shield system permits retraction of the safety shield during use, but extends the shield enclosing the needle cannula in a locked position following use. The shield system is utilized with a pen needle injector having a double-ended needle cannula mounted in a hub member received on an open end of the pen needle injector. The assembly is disposed of by removing the system and storing the assembly in the cup-shaped top cap enclosing the exposed end of the needle cannula within the cap. The top cap includes internal radial ribs preventing retraction of the shield prior to removing the top cap preventing inadvertently piercing the top cap during assembly. In addition, a bottom cap may be interlocked to the top cap to completely encompass the needle cannula, thereby ensuring safe disposal of the assembly.