Patent ID: 7432703
Filing Date: 2008-10-07
Classification: H03K

Abstract:
1. A position sensor for surveillance of a position of a traction or carrying rope of a transport installation on a grooved pulley, comprising: an enclosure; an inductive distance measuring unit arranged in the enclosure, the inductive distance measuring unit comprising an oscillating circuit including a coil having an open pot core for emitting an alternating magnetic field of the coil in a main direction in order to induce an eddy current in the rope, the inductive distance measuring unit being capable of detecting an attenuation of the magnetic field due to said eddy current; a reference device operable to define at least three distinct proximity zones within the magnetic field, which zones are situated at different distances from the sensor, the reference device determining reference values of a detection signal, the detection signal being generated based on the attenuation, each of the reference values defining a boundary of a proximity zone; a comparator for comparing the detection signal to the reference values to determine the proximity zone in which the rope is detected; and an output signaling unit for generating an output signal of the sensor containing information indicating the proximity zone in which the rope is detected.