A intravenous catheter device having a biased spring hard needle, disposed in a soft catheter. The biased spring hard needle is held within an elongated hollow barrel wherein the biased spring hard needle is extended past the first end of the soft catheter, and is further disposed in the inside of the...http://www.google.de/patents/US6193690?utm_source=gb-gplus-sharePatent US6193690 - Inclined plane latching device for an IV catheter
