Floating cover structures

Claim 1

IN A TANK STRUCTURE HAVING VERTICAL WALL PORTIONS, A COVER ADAPTED TO FLOAT ON THE MATTER IN SAID TANK AND CONSTRAINED BY SAID WALL PORTIONS FOR VERTICAL MOVEMENT IN SAID TANK; SAID COVER COMPRISING A PLURALITY OF INFLATABLE CELLS FORMED OF NORMALLY LIMP SHEET MATERIAL WHICH IS GAS IMPERVIOUS AND COMPATIBLE WITH SAID MATTER IN THE TANK, SAID CELLS WHEN INFLATED BEING ADAPTED TO REST ON A MAJOR PORTION OF THE SURFACE AREA OF LIQUID MATTER IN SAID TANK, AND A RIGID PERIPHERAL MEMBER DISPOSED IN A SUBSTANTIALLY HORIZONTAL PLANE AND IN GUIDED RELATION WITH SAID WALL PORTIONS FOR VERTICAL MOVEMENT IN SAID TANK; SAID CELLS BEING INFLATED BY GAS UNDER PRESSURE SO AS TO BE DISTENDED THEREBY INTO ENGAGEMENT AT THEIR OUTER EDGE PORTIONS ONLY WITH SAID RIGID MEMBER; SAID RIGID MEMBER SERVING TO SECURE SAID CELLS TOGETHER TO FORM A UNITARY COVER STRUCTURE, SAID RIGID MEMBER COMPRISING A METAL RING WHICH IS CHANNEL SHAPED IN SECTION TO REMOVABLY RECEIVE THE OUTER EDGES OF SAID CELLS, SAID RING COMPRISING MEANS FOR GUIDING THEREOF WITH RESPECT TO SAID WALL PORTIONS.