Toroidal fuselage structure for unmanned aerial vehicles having ducted, coaxial, counter-rotating rotors

Claim 1

A toroidal fuselage structure for an unmanned aerial vehicle having a rotor assembly having ducted, coaxial counter-rotating rotors defining respective tip path planes, the rotor assembly being supported by a plurality of radially oriented strut members, each strut member having a longitudinal axis, wherein said toroidal fuselage structure comprises: an open faced annular structure having a generally C-shaped cross-section and forming a duct wall portion that defines a duct for said toroidal fuselage structure, said C-shaped annular structure having first and second ends and forming an internal cavity; a plurality of pairs of bulkhead structures disposed in combination with said open-faced annular structure with said internal cavity formed by said open-faced annular structure and equally spaced therein, said plurality of pairs of bulkhead structures corresponding in number to the plurality of radially oriented strut members, each pair of said plurality of bulkhead structures defining a first region, adjacent pairs of said plurality of bulkhead structures defining a second region, said second region being larger than said first region, and wherein the rotor assembly is coaxially mounted within said duct by means of the plurality of radially oriented struts members mounted to said duct wall portion in said respective first regions defined by said pairs of bulkhead structures so that said first regions are intersected by the longitudinal axes of the corresponding strut members; and removable panel structures attached to said first and second ends of said C-shaped annular structure, said C-shaped annular structure and said removable panel structures in combination forming said toroidal fuselage structure of the unmanned aerial vehicle.