Substantial portions of seat belt retractors are embedded in side frame members of a car, so that their upper parts extend upward to a smaller height and occupy a smaller space in a space above the seat or floor of the car to prevent the seat belt retractors from obstructing or giving an uncomfortable...http://www.google.sh/patents/US4400015?utm_source=gb-gplus-sharePatent US4400015 - Retractors embedded in side frame members of cars
