METHOD OF AND DEVICE TO PROTECT LOAD LIFTING CRANE FROM OVERLOAD AND DAMAGE Russian patent published in 2004 - IPC

FIELD: mechanical engineering; load lifting cranes with telescopic booms.

SUBSTANCE: invention can be used in control, overload and damage protection systems of load-lifting boom cranes. According to proposed method, load moment is calculated and compared with maximum tolerable value, zone of tolerable positions of load-lifting boom equipment is set, actual position of said equipment is found and compared with tolerable position zone after which, depending on obtained data, switching on of hydraulic distributors of crane operating mechanisms is done or prohibited. Having received results of comparing of load moments and positions of load-lifting boom equipment, signals are generated to permit control of operating mechanisms of crane which are transmitted to hydraulic distributor sections control devices which are made electrohydraulic of those operating mechanisms of crane switching on of which is not dangerous to crane and then said operating mechanisms are switched on. Crane overload and damage safeguard contains electronic unit which store data on tolerable loads and zone of tolerable position of crane boom equipment provided with indicators and controls and boom tilting angle transmitter, azimuth transmitter, force sensors whose data are compared with preset parameters in electronic unit. Device is furnished with multiplexed communication line transmitting coded signals with use of corresponding address. Above indicated transmitters and sensors and controls of electrohydraulic distributors of crane operating mechanisms are connected in parallel with multiplexed communication line, said devices being furnished with matching circuits.

EFFECT: improved reliability of crane protection from overloads and damage.

4 cl, 1 dwg