An apparatus for adjusting the position of a seat comprises a rack and a clock nut that grips the rack. The rack comprises a threaded rod, while the clock nut comprises a short cylindrical body that is drilled and threaded along its diameter with internal threads corresponding to the thread diameter...http://www.google.com.au/patents/US7887020?utm_source=gb-gplus-sharePatent US7887020 - Seat track locking mechanism
