An envelope for a bed with side rails, comprised of an enveloping portion for enveloping the side rails, and a flap positionable between a mattress and mattress support and securable to the latter, to maintain the mattress in bed alignment and close off any gap between a side rail and the mattress or...http://www.google.es/patents/US4370765?utm_source=gb-gplus-sharePatente US4370765 - Envelope for a bed having side rails
