Patent US 4,452,411

A rotor having airfoil-section shaped blades is set into a fluid stream. Over a connection-or-transmission means a propeller is connected to the rotor. The fluid stream whereinto the rotor is set gives airflow energy to the rotor and revolves the rotor. The propeller is driven by the rotor over the connection-or transmission means. Since the propeller is revolved by the rotor in the fluid stream, the propeller provides a thrust. The thrust may be used to lift a weight or to drive a member. A suitable application of the arrangement is for example, to transform a multi-bladed helicopter into a gliding craft which descends under a gliding angle towards the surface of the earth, when the helicopter has a complete engine failure. Auto-rotation accidents can thereby become prevented. The device is also applicable to drive a vehicle or to lift a weight. Variable means can be applied to obtain variable thrusts in flying craft to improve their efficiencies or change from one flight-system to another flight system. In other embodiments several novel concepts for air-borne craft are provided which include emergency landing devices, retractable and extendable or relation-varifying devices for wings or propellers. Improvements are also proposed to engines and hydraulic devices to increase the power or efficiency, the lessen the weight per power output or to simplify the manufacturing and reduce the costs.