A single use medical sharp device includes an outer sheath and a shank disposed in the sheath. The shank has a leading pointed end and a trailing handle end. The shank and the sheath are inter-engaged so that the shank has an extended operational position and a retracted safe position....http://www.google.es/patents/US5478348?utm_source=gb-gplus-sharePatente US5478348 - Medical sharp apparatus with means for rendering it safe after use
Medical sharp apparatus with means for rendering it safe after use
