| 摘要 |
The device for controlling the position of a tunnelling machine has a housing (2) swivelling about an axis (3), within of which three measuring surfaces (11, 14, 18) are arranged. The first two measuring surfaces (11, 14) have openings of passage (12) for a laser beam (5), the clear width (a, c) of which diminishes in the direction of propagation of the laser beam (5). The clear width (a) of the first measuring surface (11) is smaller than the diameter (e) of the striking area of the laser beam in this measuring surface (11). The receiver elements (13, 16, 17) are arranged symmetrically in relation to the axis of the openings of passage or in case of the last measuring surface (18) in the axis and within the normal projection of the edges of the openings of passage of a preceding measuring surface (FIG. 3). |
