Container for storing or transporting liquefied gases at low temperature

Claim 1

A CONTAINER FOR STORING OR TRANSPORTING LIQUEFIED GASES AT ABOUT ATMOSPHERIC PRESSURE AND AT A VERY LOW TEMPERATURE, COMPRISING (A) A RIGID OUTER SHELL, (B) AN INSULATING SHEET OF HEAT INSULATING MATERIAL SUPPORTED BY AND WITHIN SAID OUTER SHELL, (C) A LIQUID-IMPERVIOUS INNER TANK MADE OF A MATERIAL NOT LOSING ITS STRENGTH AND DUCTILITY AT THE LOW TEMPERATURE OF THE LIQUID, AND BEING LOCATED WITHIN SAID INSULATING SHELL, (D) THE BOTTOM OF SAID TANK RESTING ON AND SUPPORTED BY AN ADJACENT SURFACE OF SAID INSULATING SHELL, (E) SAID INNER TANK HAVING VERTICAL SIDE WALLS AND A TOP WALL, (F) SAID INNER TANK BEING SUBJECT TO A DEFINITE LARGE DEGREE OF THERMAL CONTRACTION AND EXPANSION DUE TO THE TEMPERATURE DIFFERENCE BETWEEN THE EMPTY CONDITION WHEN THE TANK IS AT AMBIENT TEMPERATURE AND THE CONDITION IN USE, WHEN THE TANK CONTAINS EXTREMELY COLD LIQUEFIED GAS, (G) SAID SIDE WALLS AND TOP WALL BEING SPACED FROM THE ADJACENT SIDE SURFACE OF SAID INSULATING SHELL SUFFICIENTLY TO PERMIT SAID THERMAL CONTRACTION AND EXPANSION TO OCCUR WITHOUT INTERFERENCE OF THE ADJACENT SURFACES, (H) A PLURALITY OF SETS OF MATING KEYS AND KEYWAYS EXTENDING VERTICALLY BETWEEN THE VERTICAL SIDE WALLS OF THE INNER TANK AND OF THE ADJACENT HEAT INSULATING SHELL, A KEYWAY OF EACH SET BEING FIXED TO ONE OF SAID LAST MEMBERS AND THE MATING KEY OF EACH SET BEING FIXED TO THE OTHER OF SAID MEMBERS SO AS TO PERMIT RELATIVE VERTICAL CONTRACTION AND EXPANSION BETWEEN THE INNER TANK AND THE INSULATING SHELL, (I) THERE BEING TWO SETS OF SAID KEYWAYS LYING ON OPPOSITE SIDES OF SAID TANK IN A COMMON VERTICAL PLANE, (J) AND THE REMAINING KEYWAYS LYING IN A SECOND COMMON PLANE PERPENDICULAR TO THE FIRST PLANE, (K) SAID SETS OF KEYWAYS BEING SO ARRANGED THAT LATERAL EXPANSION AND CONTRACTION OF THE INNER TANK TENDS TO MOVE THE KEYS DEEPER OR LESS DEEPLY INTO THE KEYWAYS, (L) EACH KEYWAY BEING SUFFICIENTLY DEEP TO PERMIT SUCH LATERAL MOTION, AND BEING OF SUCH WIDTH AS TO SNUGLY ENGAGE THE SIDES OF ITS ASSOCIATED KEY, AND OF SUFFICIENT LENGTH TO PREVENT TILTING OF SAID INNER TANK BY SAID SNUG SIDE ENGAGEMENT.