SU44132A1 - An instrument for determining ground speed - Google Patents

Description

The purpose of the proposed device is to synchronize the speed of movement of marks (having the form of lines perpendicular to the course line in the field of view) with the speed of movement of the image, at a known altitude, to obtain the speed of the aircraft relative to the ground. This speed needs to be known in order to set the desired time intervals between snapshots. Currently available similar devices abroad do not provide a sufficiently satisfactory solution to this problem. So, in Zeiss, in the focal plane there is a small drum with needles thrust into it radially; the axis of rotation of the drum is parallel to the target axis of the device and is moved to the side; as the drum rotates, the needles move through the field of view. The disadvantage of this system is that the speed of movement of the point of intersection of the needle with the straight line, which follows the movement of the image point, is uneven (proportional to the tangent of the angle of rotation of the drum). With the Italian system, the ocular frame moves parallel to the course line through the focal plane.

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The gall is thrown over two rollers, the rotational speed of which is regulated by friction gear from a clock mechanism. Ne nebishstvo and difficulty of observation is obtained, because the movement occurs only along one line, which is not always convenient, since along this line it may not be convenient to observe terrain points (water, level field, etc.); observation of the side points is more or less precisely impossible.

The proposed device provides in the field of view lines perpendicular to the guidance line, moving uniformly and continuously. The speed of their movement is regulated until it becomes equal to the speed of movement of the image.

In FIG. 1 shows a longitudinal section of the lower part of the sight tube; FIG. 2- view of the device from the outside without illuminator; FIG. 3-section along the line AB of FIG. one; FIG. 4-field of view of the device with a course line visible on it and moving marks in the form of transverse lines.

A prism-cube 1 is installed behind the focal plane 6 of the lens (Figs. 1 and 3), and the hypotenuse of the upper prism is silver plated at 20-25 / o. Comprehensive prism 1 glass cylinder 2 is coated with an opaque varnish with a transparent helix 3 scratched on it 3. Cylinder 2 is reinforced in frame 4, rotating on a ball bearing 5, worn on the sight tube. In the pipe, against cylinder 2, a window is made, inclined to its axis at the angle of elevation of the helix 3.

The distances from the center of the prism 1 to the focal plane 6 and to the surface of the cylinder 2 are equal to each other.

Due to this, the image of the cylinder section through the window in the instrument tube is obtained in the focal plane without an additional optical system. The lighter consists of a light bulb and a concave mirror.

When the cylinder 2 rotates, the dashes, which are parts of the helix, will be seen moving progressively. In order to get these tips perpendicular to the heading line, the prism 1 is mounted to the heading line at the elevation angle of the helix (in the horizontal plane).

Observation with such a device turns out to be extremely easy, convenient and accurate, since the image of the light lines is superimposed on the image of the area, and it is easy to see through the light line, which has a certain thickness, whether it moves relative to the image or not. with the image).

Due to the fact that cylinder 2 is mounted on the pipe, the entire installation is very compact. I -. -,

By synchronizing the speed of movement of the marks, having the form of lines perpendicular to the guidance line, which is present in the field of view of the instrument (Fig. 4), with the speed of movement of the image at a known flight altitude, the speed of movement of the aircraft relative to the ground can be obtained.

The subject matter of the invention.

A device for determining the ground speed of an aircraft using a rotating glass cylinder carrying lines that give movable marks, characterized in that the line giving marks is made in the form of a helix, the movable marks of which are reflected by a translucent prism.

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