Inflatable structure

A method of producing a structure transformable by inflation from a collapsed condition for storage to an erect condition for use, the structure comprising an inflatable tubular framework that, when inflated, supports the structure in an erect condition, and at least one flexible web attached to and extending between two or more regions of said inflatable framework, the method comprising:

• fabricating an outer sleeve arrangement of flexible but substantially non-elastic material by cutting and stitching said material to a sleeve configuration that includes at least one bifurcation;
• separately fabricating at least two inner inflatable tubular elements of flexible, elastic, air-impermeable material by cutting and bonding the air-impermeable material to provide two separate continuous inflatable compartments, each having a configuration including at least one bifurcation, matching the configuration the outer sleeve arrangement, and each having at least two closed ends and an inflation valve;
• and
• inserting the inner tubular elements into respective parts of the outer sleeve arrangement and feeding them through the outer sleeve arrangement so that, upon inflation, the at least two closed ends of one of the inner tubular elements confront locations on the same inner tubular element or the other inner tubular element thereby to substantially fill the outer sleeve arrangement.