Abstract: The invention relates to a method for monitoring the condition of rotor blades for wind turbines. It is therefore the object of the invention to increase the accuracy of the monitoring of the condition of rotor blades of wind turbines and to allow a localization of faults or defects and their exact description. In the method in accordance with the invention, eigenvibrations of a rotor blade occurring globally at the rotor blade and locally guided elastic waves are permanently detected with time and spatial resolution using a sensor network and actuator network attached to the rotor blade or using a network arrangement of ultrasound transducers. In addition, elastic waves which are guided periodically at predefinable time intervals and which are respectively emitted by an actuator or ultrasound transducer and detected by sensors or ultrasound transducers are in so doing inspected for variations of the emitted waves.

Abstract: The invention relates to a method for monitoring the condition of rotor blades for wind turbines. It is therefore the object of the invention to increase the accuracy of the monitoring of the condition of rotor blades of wind turbines and to allow a localization of faults or defects and their exact description. In the method in accordance with the invention, eigenvibrations of a rotor blade occurring globally at the rotor blade and locally guided elastic waves are permanently detected with time and spatial resolution using a sensor network and actuator network attached to the rotor blade or using a network arrangement of ultrasound transducers. In addition, elastic waves which are guided periodically at predefinable time intervals and which are respectively emitted by an actuator or ultrasound transducer and detected by sensors or ultrasound transducers are in so doing inspected for variations of the emitted waves.

Abstract: A hinge joint comprises a hinge leaf, a closure element, a knuckle bearing, a hinge bolt defining a hinge joint axis and pivotally mounting the closure element via the knuckle bearing, a hinge bearing having a base securable adjacent to an edge of an opening, the hinge bearing having legs between which the knuckle bearing is positioned and which carries the hinge bolt, the knuckle bearing having at least one first protrusion extending axially outwardly and arranged concentrically relative to the hinge bolt, one of the legs having an axially inwardly extending protrusion which axially overlaps the first protrusion, the hinge leaf together with the closure element being arranged so that it can be removed from the hinge bearing only after removal of the hinge bolt and after opening the closure element through a predetermined pivot angle, the first protrusion being annular, the second protrusion being formed as an enclosing retainer of one of the legs and arranged radially outside of one of the first protrusions,

Abstract: A hoisting apparatus mounted on the deck of a ship for picking floating objects from the sea having an articulated lifting arm which extends over the side of the ship and gripping device suspended from the end of the arm for grasping objects in the water. The arm is actuated by an hydraulic cylinder connected to a source of high pressure liquid which may be dumped into the cylinder instantaneously in response to the closing of the gripping device around the object. The liquid is pressurized by a compressed gas. The apparatus produces a high hoisting speed and lifts the object very quickly from the water.

Abstract: A scissors-type, free-fall grab is disclosed for picking up ground samples from a sea bed. The grab includes two grab halves which may pivot relative to one another. A transverse bar engages the upper ends of the grab halves to hold the grab in its opened position. This transverse bar is attached by a cable arrangement to a buoyancy member. Upward movement of the buoyancy member causes the transverse bar to become disengaged from the upper ends of the grab halves and forces the grab halves to move to their closed position. The grab carried weights which fall off of the grab as the grab moves from its opened to its closed position.