A. Field of the Invention
The present invention relates to a measuring device for track building machines, which comprises an optical receiver device for receiving light waves emitted by light sources situated on both sides of and at a distance from the measuring device, and an evaluation device.
B. Description of the Prior Art
In the construction of new track installations or the restoration of existing track installations, particularly for railways, measuring devices are required to enable the course of the track to be accurately determined and, in particular, to be adapted to requirements or corrected. Measuring devices of this kind conventionally consist of an optical measuring system utilising three reference points at a distance from one another on the path of the track for the purpose of determining the course of the latter. For straight horizontal stretches these three points must lie in one line, but on curves, for example, these three reference points must be offset to a certain extent in relation to one another. This offset is measured and evaluated. The layout of the track must if necessary be corrected in accordance with the evaluation.