Insulated shipping container for biological materials

Claim 1

AN INSULATED CONTAINER FOR TRANSPORTING MATERIALS REQUIRING REFRIGERATION BY LIQUID NITROGEN WHICH CONTAINER COMPRISES (1) A RIGID SELF-SUPPORTING OUTER SHELL, (2) AN INNER VESSEL ENCLOSED BY AND SPACED FROM THE OUTER SHEEL SO AS TO DEFINE AN INTERVENING EVACUABLE SPACE, (3) A COMPSOSITE INSULATION MATERIAL IN THE EVACUABLE SPACE, COMPOSED OF (A) A RADIANT HEAT REFLECTING COMPONENT AND (B) A LOW HEAT CONDUCTING COMPONENT DISPSOED IN RELATION TO THE RADIANT HEAT REFLECTING COMPONENT SO AS TO MINIMIZE THE TRANSFER OF HEAT ACROSS THE EVACUABLE SPACE THROUGH THE RADIANT HEAT REFLECTING COMPONENT BY CONDUCTION, SAID COMPOSITE INSULATING MATERIAL SERVING TO MINIMIZE HEAT TRANSFER ACROSS THE EVACUABLE SPACE BY RADIATION AND CONDUCTION AND SAID COMPOSITE INSULATION MATERIAL HAVING A THERMAL CONDUCTIVITY NO GREATER THAN ABOUT 3.2X10-5 B.T.U. PER HOUR, *F. SQUARE FOOT PER FOOT, (4) A SPECIMEN HOLDER COMPOSED OF AN INTEGRAL MASS OF A SAND-LIME FILLER IN THE INNER VESSEL COMPRISING MAINLY CALCIUM SILICATE IN WHICH THE RATIO OF SILICA AS SILICON DIOXIDE TO CALCUIM AS CALCIUM OXIDE IS BETWEEN 1 AND 1.5, THE FILLER ALSO CONTANING BETWEEN 4 PERCENT AND 20 PERCENT BY WEIGHT, BASED ON THE TOTAL WEIGHT OF THE FILLER, OF AN INERT METAL FIBER AND THE FILLER HAVING A POROSITY OF 86 PERCENT TO 93 PERCENT, SAID SPECIMEN HOLDER HAVING VOIDS IN THE CENTRAL PORTION THEREOF ADAPTED FOR STORING THE MATEIRALS REQUIRING REFRIGERATION (5) ACCESS MEANS FOR INTRODUCING THE SPECIMEN HOLDER INTO THE INNER VESSEL AND FOR INTRODUCING THE OBJECTS REQUIRING REFRRIGERATION INTO THE VOIDS IN THE SPECIMENT HOLDER AND (6) SEALING MEANS FOR MINIMIZING HEAT LEAK THROUGH THE ACCESS MEANS INTO THE CONTAINER AND ESCPAE OF LIQUID NITROGEN FROM THE INNER VESSEL WHILE PROVIDING PASSAGES FOR THE ESCAPE OF NITROGEN VAPOR FROM THE INNER VESSEL.