An axially compliant injection nozzle for plastic molding machines incorporating a valve actuated by differential motion between the mold and the conditioning chamber comprises a tappet engaged on the stem of that valve and entrapping a valve spring between the valve seat and the tappet. The nozzle has...http://www.google.es/patents/US3934626?utm_source=gb-gplus-sharePatente US3934626 - Anti-drip injection nozzle for plastic molding
