Japanese National Railways

Kunio Takeshita

Satoru Kishimoto

Yasushi Shirota

Yoshio Ando

For optically measuring rail displacement, a light projector with a slit plate, a reflection mirror for light projection, a reflection mirror for light reception and a light receptor with a slit plate are installed at specified distances from one another on the underside of the body of a track inspection car on both sides in the longitudinal direction thereof. The light projector, the reflection mirror for light projection, the reflection mirror for light reception and the light receptor are arranged so that the light emitted from the light source in the light projector passes through the slit and, being reflected by the reflection mirror for light projection, is converged onto a measuring axis connecting the points as to which measurement is being made on the opposed rails which constitute the track at at least one of the rails to form a bright spot or band of light. The light receptor receives only the light from the rails at said measuring axis via the reflection mirror for light reception and then the slit in said receptor. In the light receptor a deviation of the reference measuring points indicated by movement of the bright spot or band during the running of the track inspection car along the track is detected; and by comparing the deviation with the position of said reference measuring points when the rails are in the correct position, the rail displacement can be measured.

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Hachioji, Japan

Kunio Takeshita