Patent ID: 6415208
Filing Date: 2002-07-02
Classification: B61K,G01B

Abstract:
Apparatus for surveying a rail, comprising:a transmitter unit arranged on the rail and emitting a laser beam which is aligned longitudinally in the direction of a rail and is incident on a measuring surface, wherein the transmitter unit has an electronic level to maintain the emitted laser beam stabilized in position; a detector unit designed for mobility along the rail and having at least two vertically rotatably supported guide rollers arranged in spaced-apart relation longitudinally in the direction of the rail, and forced against opposite side surfaces of the rail for guiding the detector unit during travel, wherein each of the guide rollers has on one side of the rail a fixed pivot axis and is forced on the other side of the rail against a respective one of the side surfaces of the rail, at least two running rollers arranged in spaced-apart relation longitudinally in the direction of the rail for travel on the running surface of the rail, wherein the running rollers are horizontally supported for rotation about pivot axes which are aligned transversely to the longitudinal rail direction, with at least one of the running rollers being designed for moving the detector unit, and a photodetector which confronts the laser beam and has a matrix in the form of a plurality of neighboring optical sensor elements for generating electric output signals in response to the incident laser beam on the measuring surface, said photodetector being an opto-electronic camera, said detector unit including a transparent diffusion screen, positioned anteriorly of the camera, to define the measuring surface which is optically projected onto the matrix of the photodetector; an electronic evaluation unit receiving the output signals from the sensor elements for determining in purely electronic fashion the point of impact and thereby the position of the laser beam on the measuring surface; and a proximity sensor for determining a change in distance between the transmitter unit and the detector unit.