A light-blocking safety shutter is mounted in a fiber-optic adapter housing that mates with a standard fiber-optic male connector of the type with a fiber-containing ferrule protruding from a forward end. The shutter is mounted in the insertion passage of the adapter and is held in the light-blocking...http://www.google.de/patents/US6688780?utm_source=gb-gplus-sharePatent US6688780 - Cantilevered shutter for optical adapter
