| 摘要 |
<p>A revolving nose piece has a number of optical components, for example, objectives, condensers, lenses, filters and diaphragms, each of which can be brought separately into working position. The revolving nose piece has a motorized driving device (1-4), a coding device (12a - 12c; 24a - 24c) for identifying or preselecting a component to be brought into a working position, and locking means (7, 7a; 8) for positioning the optical component in working position, and marking and controlling means (13; 13a), with which the number of revolutions of the nose piece can be adjusted in function of the relative position of the latter. In particular, the said device makes it possible to bring a motor-driven nose piece (5) with a high number of revolutions into a reference position so that a given reduction of the speed of rotation of the nose piece (5) is achieved shortly before it reaches this working position. In addition, the nose piece (5) is decoupled from the driving device (1-4), which includes an electric motor (1) and a tachometer generator (1a), so that the exact working position is reached by purely mechanical means by locking means (7, 7a, 8). A process for adjusting the number of revolutions of the revolving nose piece is also described.</p> |
