Pleated Structures - Pleated umbrellas

Pleated umbrellas

Pleated umbrella (prototype, 2014)

Umbrellas work quite effectively if pleated.

Pleats reduce the need for the fabric to be able to sustain tensile forces. They divide the structural roles more cleanly into three different categories:

Compression;
Tension;
Waterproof skin.

With a greater division of roles, each element can concentrate on playing its own role more effectively, without having to do several things at once.

Cables also act to support the fabric more frequently, reducing the area span it must cover without support. Alternatively, for the same clear span, the number of compression elements goes down - reducing the overall weight.

There is a much-reduced need to use a fabric that can curve into anticlastic shapes.

Also, a pleated umbrella is much less likely to turn itself inside out.

As with domes, thickness adds strength. Pleating generates three-dimensional structure, and increases structural integrity.

However, probably what will help this kind of umbrella to eventually enter the marketplace is that they are clearly unusual and cool.