System for detecting trains

Abstract

A system for detecting one or more vehicles, such as a train, on a rail track, includes at least one optical conductor extending near and parallel to the rail track with a light source and light detector coupled thereto. One or more sensors are coupled to the rail track and include the light conductor, which sensors affect the light attenuation in the light conductor locally upon the presence of the vehicle. The sensor includes a free elongated element, which is connected to the mass of the sensor housing via an elastic hinge connection. One end of the element lies against the light conductor running through the sensor housing, which one end subjects the conductor to a microbending in dependence on displacement of the rail. The elongated element is a pin which runs through a drilled block which is integral with the elastic hinge connection, and at its other end is provided with an outstanding pick-up arm of which the end rests on a contact surface of the fixed substructure of the rail such that the sensor is adapted to detect a displacement or sag of the rail. The arm end may also be free or the pick-up arm may be eliminated such that the sensor is adapted to detect vibrations of the rail. For the purpose of measuring modal noise, the system may comprise an additional optical conductor disposed in close contact with the rail. The conductor may be suspended in a tube provided with perforated partitions, the optical conductor having vibratory masses attached to it.

Dependencies are inferred from the claim text.