A rigid endoscope includes an outer housing subassembly that supports an optics subassembly. The outer housing subassembly includes concentric tubes with optical fiber for providing object illumination. The optics subassembly includes a tubular sheath sealed at both ends for carrying lenses and other...http://www.google.co.uk/patents/US7758498?utm_source=gb-gplus-sharePatent US7758498 - Endoscope with relief of axial loading
