| 摘要 |
<p>Use is made of a levelling and aligning machine and an emitter system installed on a carriage parked on the track and emitting a fan-shaped beam in the horizontal plane for the levelling operation and a fan-shaped beam in the vertical plane for the aligning operation, these beams defining an absolute measurement base. Two receivers for the levelling operation and the aligning operation are provided in order to centre themselves, at each measurement, at the line of impact of one or the other of the said beams. These two receivers are placed on a special measurement carriage (10) at a fixed distance (b) in front of the front measurement carriage (9) of the relative measurement base, making it possible to store a specific number of aligning and levelling values. A display (EC), such as a screen, a recorder or other means, is provided in order to display these values. In a curve of the track, the vertical beam (Fr) defines a chord of this curve and the adjusted position of the receiver defines the actual value of the deflection of the curve. A computer calculates the reference value of the deflection and the divergence of the two values which determines the aligning correction. <IMAGE></p> |
