1. Field of the Invention
The present invention relates to an apparatus for detecting an abnormal condition of a main rope for an elevator.
2. Description of the Prior Art
Recently, developments which respect to high speed and high rise elevators have been remarkable. The wire ropes such as a main rope of such elevators have been used under remarkably severe conditions in comparison with the conventional elevator from the viewpoints of twist, slip and wearing. Accordingly, element wires of the wire rope have been easily cut. The damage of the wire rope causes not only the trouble of the wire rope but also causes serious troubles that the element wires and the strand projected from the wire rope touch instruments in a hatchway so as to induce a serious accident with respect to the instrument or an accident involving completely cutting the wire rope. The safety of elevators has been remarkably damaged by such developments.
However, the problem of cutting of the element wires and the strand has not easily occur when the travel height is high and the wire rope is long. Even so, sometimes, the cutting problem has not found and has been suddenly occurred during the driving of the elevator.
When the elevator is driven with a cut of the strand, the strand is gradually loosed to cause the damage of the instruments in the hatchway by the cut strand.