Apparatus for containing a non-rigid or fluid material

Claim 1

A VARIABLE VOLUME STORAGE DEVICE FOR STORAGE OF CHEMICALLY UNSTABLE FLUID MATERIAL IN THE MINIMAL VOLUME CONDITION AT A PRESELECTED PRESSURE, SAID DEVICE COMPRISING: A RELATIVELY NARROW SPACING RING PROVIDED WITH A PORT; A PAIR OF GAS-POROUS FLEXIBLE BLADDER MEMBERS FASTENED AT THEIR PERIPHERIES TO EACH SIDE OF SAID SPACING RING IN CONFRONTING RELATIONSHIP AND ADAPTED TO RETAIN FLUID IN A STORAGE AREA DEFINED BY SAID BLADDERS AND SAID SPACING RING; A PAIR OF GAS-POROUS RESILIENT BACKING MEMBERS, EACH OF SAID BACKING MEMBERS RIGIDLY RETAINED PROXIMATE TO SAID RING AT THEIR PERIPHERIES IN CLOSE ABUTTING RELATIONSHIP TO ONE OF SAID BLADDER MEMBERS, RESPECTIVELY, ON THE OUTWARD FACE THEREOF, AND BIASING SAID BLADDER MEMBERS TOWARDS SAID MINIMAL VOLUME CONDITION SAID BACKING MEMBERS HAVING THE SAME CROSS SECTIONAL THICKNESS FOR ALL VOLUMETRIC CONDITIONS OF THE STORAGE AREA DEFINED BY SAID BLADDERS AND SAID SPACING RING; A PAIR OF SYMMETRICALLY SHAPED RIGID VESSELS, EACH OF SAID VESSELS RIGIDLY RETAINED PROXIMATE TO THE PERIPHERY OF ONE OF SAID BACKING MEMBERS IN SEALING RELATIONSHIP THERETO;