Pneumatically-actuated roll-up closure

Claim 1

AN IMPROVED APPARATUS FOR SELECITIVELY OPENING AND CLOSING AN OPENING IN A STRUCTURE, SAID OPENING HAVING CERTAIN DIMENSIONS, SAID APPARATUS COMPRISING, IN COMBINATION, A FLEXIBLE HOLLOW CLOSING MEANS HAVING DIMENSIONS GENERALLY CORRESPONDING TO SAID CERTAIN DIMENSIONS OF THE OPENING AND MOUNTED ON SAID STRUCTURE ADJACENT AN OPENING FOR MOVEMENT BETWEEN A FIRST POSITION SPACED FROM SAID OPENING AND A SECOND POSITION IN WHICH SAID MEANS CLOSES SAID OPENING, A RESILIENT MEANS CARRIED BY SAID CLOSING MEANS AND MOVABLE THEREWITH BETWEEN SAID FIRST POSITION IN WHICH AT LEAST SOME SIGNIFICANT PORTION OF THE CLOSING MEANS IS WOUND IN TIGHT CONVOLUTIONS AND SAID SECOND POSITION IN WHICH THE CLOSING MEANS IS EXTENDED TO CLOSE SAID OPENING, SAID RESILIENT MEANS COOPERATIVE WITH SAID CLOSING MEANS TO URGE SAID CLOSING MEANS TO SAID FIRST POSITION, AND REVERSIBLE FLUID MEANS COMMUNICATING WITH THE INTERIOR OF THE HOLLOW CLOSING MEANS FOR SELECTIVELY INCREASING THE PRESSURE IN SAID INTERIOR PORTION RELATIVE TO THE PRESSURE OUTSIDE SAID CLOSING MEANS TO EXTEND THE CLOSING MEANS AGAINST THE ACTION OF THE RESILIENT MEANS AND CLOSE THE OPENING, AND DECREASING THE PRESSURE IN SAID INTERIOR PORTION TO ALLOW THE RESILIENT MEANS TO RETRACT SAID CLOSING MEANS TO CLEAR THE OPENING.