METHOD TO PROTECT LOAD-LIFTING CRANE FROM OVERLOADS Russian patent published in 2006 - IPC B66C23/88 B66C13/18 

FIELD: materials handling equipment; overload safeguards of load lifting cranes.

SUBSTANCE: according to proposed method, values of loads tolerable at different spatial positions of crane boom or load-gripping member are previously determined and memorized. In process of crane operation, parameters are measured characterizing current load of crane and current spatial position of boom or load-gripping member and current value of load is compared with tolerable memorized load. If current value of load exceeds tolerable value, crane mechanisms are switched off to interlock operation of crane. Prior to operating the crane, maximum values are preset for at least one diagnosing parameter characterizing condition of load-lifting crane. In process of operation of crane, current value of at least one diagnosing parameter is determined and compared with maximum tolerable one, and depending on results of comparing, warning signals for crane operator are shaped, or load value is changed to value tolerable for current spatial position of boom or load-gripping member. Natural magnetic dissipation fields of most loaded units of crane, values of play or clearance in movable joint can be used as diagnostic parameters and said values should be recorded in nonvolatile memory with possibility of reading out.

EFFECT: improved overload and damage protection of load-lifting crane, increased service life of crane and improved on -like checking of crane condition.

5 cl, 1 dwg