Integrally stiffened and formed, load carrying structures comprising a plurality of elongated thin-walled tubes placed co-extensively in a complementary side-by-side fashion which together form a hollow structure having a desired external contour. Integral skins forming the external and internal surfaces...http://www.google.es/patents/US20030146346?utm_source=gb-gplus-sharePatente US20030146346 - Tubular members integrated to form a structure
