Patent ID: 8160786

Claim:
A mobile crane comprising at least one memory unit in which for various crane parameters, stability limit curves or values are stored and which should not be exceeded to ensure stable, safe crane operation, and means for monitoring position of center of gravity of the crane from individual limit values of the various parameters and signaling if position of the center of gravity approaches, reaches or exceeds any of these limit values, wherein said crane comprises horizontally-extendable props ( 20 ) and supporting cylinders ( 30 ) each positioned at an end of a respective ( 20 ) and being vertically extendable, a line ( 50 ) connecting respective ends of the props ( 20 ) at which the supporting cylinders ( 30 ) are positioned defining a tilting edge ( 50 ) or limit value, said means checking current position of the extendable and retractable props ( 20 ) which serve to support the mobile crane, in dependence on the actual position of the props ( 20 ) reached, determine the tilting edge ( 50 ) of the mobile crane as limit value, and whether position of the center of gravity approaches, reaches or exceeds any of these limit values ( 50 ) and the operating condition of the mobile crane lies within, approaches or exceeds any of the limit values ( 50 ).