METHOD OF AND DEVICE FOR MEASURING AZIMUTH ANGLE OF LOAD- LIFTING CRANE Russian patent published in 2003 - IPC

FIELD: mechanical engineering; load-lifting equipment. SUBSTANCE: invention relates to system protecting load-lifting cranes from overload and overturning. According to proposed method magnetic field in induced which is stationary relative to crane running gear and two magnets of sensors mounted on crane turntable and shifted relative to each other through quarter of revolution are exposed to action of said magnetic field. As a result, two voltage are formed proportional to side and cosine of angle between direction of magnetic field and angle of turning of crane turntable. Polarities of said voltages are found and, basing on obtained results, quadrant of azimuth angle is determined. Azimuth angle within each quadrant is judged by said voltages. Proposed device contains magnetic field source-permanent magnet secured on crane running gear and two sensors made in form of Hall-effect devices or magneto-resistive bridges which are secured on crane turntable with shift through quarter of revolution. Inputs of sensors are connected to supply source, and outputs, to inputs of measuring circuit (microcontroller). Invention provides possibility of noncontact measurement of azimuth angle at offset arrangement of devices of running gear and turntable of crane. EFFECT: improved reliability of measurements. 6 cl, 2 dwg