Cargo containers

Claim 1

A cargo container comprising a. a first rigid member, b. a second rigid member, substantially coextensive with said first rigid member and movable towards and away from said first rigid member between an inner position relatively close to said first rigid member and an outer position relatively far from said first rigid member, c. a flexible fluid impermeable sleeve having a plurality of preformed corrugations therein and extensible in concertinalike fashion, d. sleeve securing means sealingly securing said ends of said sleeve peripherally to said first and second rigid members respectively whereby said sleeve and said rigid members together form an expansible fluidtight vessel, said sleeve securing means including i. a peripheral flange on at least one said rigid member and defining a channel having a constricted opening, which channel is adapted to receive one end of said sleeve, and ii. an inflatable member within said channel, whereby on inflation of said inflatable member said one end is sealed in fluidtight fashion peripherally to said rigid member, e. continuous rigid outer walls fast with said first rigid member and adapted to guide said second rigid member in its movement between the said inner and outer positions, to support said sleeve against pressure within said vessel and to protect said sleeve against external damaging influences, and f. spacer means mounted within said vessel and spaced from said rigid outer walls so as to provide between said first and second rigid members and between the said spacer means and said rigid outer walls in said inner position of said second rigid member a dead space to receive said sleeve.