A needle guard for a syringe or other instrument with a sharp point is disclosed having a protective sleeve with a fitting, and having a retracted position and a locked extended position, that may be used with or added to a conventional syringe and needle assembly. Prior to and during use of the needle,...http://www.google.es/patents/US5019051?utm_source=gb-gplus-sharePatente US5019051 - Hypodermic needle guard
