A pressure relief support system utilizes a self-adjusting approach to maintaining generally constant pressure in fluid support bladders. A constant force, such as from a constant force linear spring or from a counterweight system, is applied directly to a fluid support bladder or to a reservoir in fluid...http://www.google.fr/patents/US5652985?utm_source=gb-gplus-shareBrevet US5652985 - Self-adjusting pressure relief support system and methodology
Self-adjusting pressure relief support system and methodology
