Abstract: A rear axle steering system for a mobile crane includes at least one actively steered rear axle with wheels arranged thereon. A rear axle steering system of this type is provided with a hydraulic steering system including one or more hydraulic steering cylinders of which a particular number are in each case associated with an actively steered rear axle in order to steer this actively steered rear axle in a desired manner. A braking system is adapted to individually brake each wheel of the at least one actively steered rear axle. In the event of an error in the hydraulic steering system, a control system actuates the braking system in such a way that by selective braking of at least one wheel of the actively steered rear axle, which is affected by this error, the rear axle is brought to a predetermined, desired steering position. A method of steering a rear axle, with wheels of a mobile crane arranged thereon, by means of a hydraulic steering system.

Abstract: A rear axle steering system for a mobile crane including at least one actively steered rear axle with wheels arranged thereon. A rear axle steering system of this type is provided with a hydraulic steering system including one or more hydraulic steering cylinders of which a particular number are in each case associated with an actively steered rear axle in order to steer this actively steered rear axle in a desired manner. A braking system is adapted to individually brake each wheel of the at least one actively steered rear axle. In the event of an error in the hydraulic steering system, a control system actuates the braking system in such a way that by selective braking of at least one wheel of the actively steered rear axle, which is affected by this error, the rear axle is brought to a predetermined, desired steering position. A method of steering a rear axle, with wheels of a mobile crane arranged thereon, by means of a hydraulic steering system.

Abstract: A method is provided for deriving software tests from use cases. Thereby an activity digram is used to represent the possible use case scenarios. The test case scenarios are derived by applying coverage metrics on the activity diagram. The activities of the diagram are matched with an appertaining test. A test idea document is produced from the test case scenario. System test scenarios are created by concatenating the test case scenarios to a walk-through of the system. The system test cases are further enriched with activities to ensure the test precondition and to verify the test case scenario result. A test design document is produced for the system test.

Abstract: A circuit configuration for protecting the on-board electrical system of a motor vehicle includes an input connected to a voltage source, an output connected to a load and a ground connection being common to both the input and the output. A current stabilizer regulates an output current. A switch controls the current stabilizer as a function of the output current. An overload switch carries an overload current from the input through the current limiter to the output upon the appearance of an overload at the output, and carries a short-circuit current from the output through the excess voltage switch to ground upon a short circuit at the output to an excess voltage.

Abstract: Open-end spinning device, including a rotor housing, a spinning rotor being disposed in the rotor housing and having an inner surface, a housing cover having a fiber feeding channel formed therein, a thread delivery orifice being at least partly disposed in the cover and having a hard and wear-resistant material surface at thread deflection locations, and a surface layer of wear-resistant material disposed on the inner surface of the spinning rotor, the surface layer having areas of different wearability distributed therein.

Abstract: Open-end spinning device, including a rotor housing, a spinning rotor disposed in the rotor housing, a housing cover having a fiber feeding channel formed therein being in communication with the rotor, a thread delivery channel disposed in the cover, and a thread delivery orifice being at least partly disposed in the cover and being in communication with the thread delivery channel and rotor, the orifice having a hard and wear-resistant surface layer at thread deflection locations, the surface layer having areas of different wearability distributed therein.