| 摘要 |
<p>The machine comprises a device for shifting the track which is controlled by a device for the detection of its geometrical defects. The detection device comprises three rail feelers to which there are connected a light-ray emitter (17), a screen (18) having two parallel delimiting edges (19, 20) and a receiver (21) having two identical photovoltaic cells (22, 23) arranged in such a manner that the sum of their irradiated surfaces (u+d) is a constant and their difference (u-d) is proportional to the displacements of the screen. The signals produced by the two cells are processed in an electronic circuit comprising a totalizer (28) delivering a signal for the control of the displacement device proportional to the said difference (u-d) and a piloting circuit (30, 41, 42) of the emitter to maintain the irradiation of the two cells constant by comparison of a signal proportional to the said sum (u=d) with a reference signal (S0).</p> |
