SU46378A1 - Spotting device for telescopes - Google Patents

Description

Aiming with telescopes: a cross of filaments at the displayed signals for various kinds of geodetic works is not always convenient.

In the event that it is necessary to sight against a bright sky, for example, on a flagpole of a tower or on a mast, the latter is drawn in the field of view with a dark image.

When the crosshairs are aimed at the dark image, the cross is lost to the observer’s eye and thus the possibility of precise pointing is excluded.

At first, the crosshairs were made as the intersection of real spider cocoon threads, then the need for more accurate guidance led to a so-called grid-glass plate with thin strokes.

It should be considered that only traditions keep the use of the cross in the telescopes, as a relic of ancient diopters, although it must be admitted that for a number of devices the cross has undoubtedly constructive advantages (portable military devices).

The described device is a telescope without a cross of filaments.

Aiming is achieved by combining in field of view two)

images of one ordinary, drawn by rays that have passed only through lens 2 (Fig. 1) and the second image, drawn by rays that have previously passed through a prism.

This conventional rectangular prism (I) is placed in front of the lens, with its hypotenuse border set approximately parallel to the main optical axis of the lens. Accurate installation is not necessary, just as the installation of a cross of filaments exactly on the main optical axis of the lens is optional.

When aiming at a point lying on that (side in the general case) axis of the lens, which is parallel to the hypotenuse edge, two combined images of the point are obtained in the focal plane (Fig. 2). When turning the pipe at a small angle cs image

points are diverted by an angular value of 2cp and thus allowing

the strength of the eye seems to increase by two times, which is the significant value of the telescope with the proposed device (Fig. 3).

The fact that one of the images is wrapped is not a hindrance.

Pipe with the proposed device can be used primarily in the following tools:

1) in theodolites for phototriangulation;

2) in phototheodolite heads;

3) in exact universalists for triangulation of classes I and II.

The subject matter of the invention.

A device for aiming in geodesic instruments in the optic tubes, characterized by using a rectangular glass prism L placed in front of the lens 2 and placed a hypotenuse plane parallel to the optical axis of the tube, in order to align the direct image of the target by means of beams falling directly on the lens and reverse target images by means of rays that previously passed through a rectangular prism.