US Patent 9708166 Self-propelled trolley

The invention describes a self-propelled trolley for handling a wind-turbine blade, which trolley comprises a driving device for propelling the trolley between locations; and a lifting device, which lifting device is realised to raise and lower the wind-turbine blade. The invention also describes a method of handling a wind-turbine blade, which method comprises the steps of positioning a self-propelled trolley according to any of the preceding claims at a point underneath the wind-turbine blade; actuating a lifting device of the self-propelled trolley to raise or lower the wind-turbine blade; and controlling a driving device of the self-propelled trolley to propel the trolley between locations.