A nonreusable medical device has a needle for injecting or collecting fluid which is retractable by depression of a plunger slidingly mounted in the medical device. A front-mounted retraction mechanism has a needle holder connected to the needle. The needle holder is supported along the axis of the device...http://www.google.de/patents/US5385551?utm_source=gb-gplus-sharePatent US5385551 - Nonreusable medical device with front retraction
