A sensor mountable within a hydraulic cylinder provides a precision signal indicative of the position of the piston. The sensor includes a flexible connector attached between the cylinder piston and a converting element for sensing the piston displacement. The converting element comprises a pick-up spool,...http://www.google.com.au/patents/US6694861?utm_source=gb-gplus-sharePatent US6694861 - Precision sensor for a hydraulic cylinder
