Electromagnetic inspecting apparatus for magnetizable wire rope

An electromagnetic inspecting apparatus for electromagnetically detecting a defect present in a plurality of magnetizable wire ropes, each of said wire ropes having a plurality of strands, each of said strands including a plurality of steel wires, each of said wire ropes moveing in parallel with each other in their longitudinal direction, and including a plurality of electromagnetic inspecting units provided for the inspection of said plural magnetizable wire ropes respectively, each of said units comprising:

• a first magnetic pole disposed opposite to an associated one of said magnetizable wire ropes;
• a second magnetic pole having a polarity different from that of said first magnetic pole and disposed opposite to said associated magnetizable wire rope at a position spaced apart by a predetermined distance from said first magnetic pole in said longitudinal direction, said predetermined distance being selected to be a multiple integer of the strand pitch of said magnetizable wire rope;
• a detecting core disposed opposite to said associated magnetizable wire rope at a position intermediate said first and second magnetic poles;
• a detecting coil wound around said detecting core to make a differential response to flows of leakage flux appearing due to the presence of a defect in said associated magnetizable wire rope thereby generating an electrical output signal indicative of the result of its response;
• and
• a yoke magnetically coupling said first and second magnetic poles and said detecting core at the portions remote from said associated magnetizable wire rope.