Pressure controlled cargo dunnage bulkhead system for freight cars

Claim 1

AN EXPANDABLE BULKHEAD UNIT FOR PROVIDING A LOW SHORTING PRESSURE IN A RANGE OF ONE-HALF TO THREE POUNDS PER SQUARE INCH BETWEEN CARGO UNITS IN A FREIGHT CARRYING CONVEYANCE, COMPRISING: A PAIR OF PANEL MEMBERS, A PLURALITY OF EXPANDABLE MEMBERS DISPOSED IN SPACED RELATIONSHIP WITH ONE ANOTHER BETWEEN SAID PANEL MEMBERS, EACH EXPANDABLE MEMBER HAVING A SURFACE AREA HAVING A MAXIMUM DIAMETER OF SUBSTANTIALLY 12 INCHES IN CONTACT WITH EACH OF SAID PANEL MEMBERS AND HAVING A CHAMBER EXPANDABLE IN RESPONSE TO INCREASE IN PRESSURE THEREIN OCCASIONED BY CHANGES IN AMBIENT PRESSURE THE TEMPERATURE AND CONTRACTABLE IN RESPONSE TO DECREASE THE PRESSURE THEREIN OCCASIONED BY CHANGES IN AMBIENT PRESSURE AND TEMPERATURE TO MOVE SAID PANEL MEMBERS APART OR TOWARD EACH OTHER, RESPECTIVELY, AND INPUT MEANS ON EACH BAG FOR CONNECTION IN COMMON TO A SUPPLY MEANS HAVING A PRESSURE WHEN CONNECTED TO SAID EXPANDABLE MEMBERS HAVING SAID SURFACE AREA INFLATES SAID EXPANDABLE MEMBERS TO EFFECT AN EXERTION OF A PRESSURE IN SAID PRESSURE RANGE ON SAID CARGO BY SAID PANEL MEMBERS.