DE32592C - Range finder - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

CLASS 42: Instruments.

JOSEF MAYER in BRUNECK (Tyrol). Range finder.

Patented in the German Empire by ao. January 1885.

The establishment of the present range finder is based on the fact that one does not arrive until the Objects, the distance of which is to be determined, or initially this object one dimension to be determined easily with the greatest possible accuracy perpendicular to the to measuring line, then dividing one into a certain number of equal parts transparent ruler of precisely known length parallel to the estimated dimension and at a known distance from the eye between the eye and the estimated dimension and now observe how many parts of the scale fall into the estimated dimension.

The outermost rays of sight to the ends of the estimated dimension, that dimension itself and that part of the staff which is bounded by the rays of sight evidently two similar triangles, one of which is the height and the base line, and of the other of which the baseline is known. So one can get out of proportion very easily Calculate the unknown height of one triangle, namely the distance to be determined.

To facilitate the resolution of this proportion and the errors made in the comparison very large dimensions with very small ones always have to arise, to be reduced as much as possible, is the length of the in a certain The distance in front of the scale to be held is chosen so that the line is below an angle of vision at which a certain larger dimension appears in a certain greater distance would appear. The accompanying drawing shows in Fig. 1 one of the Invention according to set up simple instrument for determining distances in Steps, the transverse dimension on the object, its distance to be determined can be estimated in steps, meters or man's width. Fig. 2 illustrates the Use of the instrument.

The instrument consists of a metal plate in the shape of an equilateral triangle, which has lugs abc on its three sides. If the instrument is held at a distance of τοη 56.25 cm in front of the eye, the lengths of the attachments correspond to the viewing angles at which, at a distance of 100 paces, the dimensions of 4 m, 4 paces and 4 man's breadth appear. Accordingly, these approaches are designated M, S and MB , and depending on whether the transverse dimension of the object or, first of all, of the object whose distance is to be measured, is estimated in meters, steps or man's width, one uses one or the other when determining the distance the other of the approaches. Each attachment is divided into 16 parts by incisions, and the _{incisions marking Y 8} , Y ₄ and Y _{2 of} the total length of the attachment are made at different depths to produce the necessary overlap. In order to be able to hold the instrument in front of the eye exactly at the specified distance of 56.25 cm, for which it is designed, it is connected to a cord of the desired length by a bracket inserted in its center so that it can be rotated . ■

Claims (1)

As can be seen from Fig. 2, after the transverse dimension xy or X ₁ y _x has been measured on the object whose distance is to be determined, or first of all, the instrument is held in front of the eye 0 at the distance given by the cord, that one end m of the relevant attachment α b or c cuts off with one end χ or X _{1 of} the transverse dimension xy or X ₁ JKi, whereupon one observes at which notch the line of sight to the other end jK or V _{1 of} the transverse dimension intersects the attachment. As is clear from what has been said above, the relationship between the length of the attachments mm _x and their distance m 0 " from the eye is like 4 m, 4 steps or 4 man's widths to 100 steps nt M ₁ = m JM ₁ m W ₁
- ^ - and m η = - the pro- portions ο χ: ο m = xy: m η and 0 X ₁ : 0 m = X ^ y ₁ '. Mn ₁ , from which one can get by substitution the known value receives ο χ: ι οο = χ γ: - 4 and ο X ₁ : ΐοο = X ₁ JK ₁ : ~ · Consequently, the searched distance οχ = looxy, and in a similar way one finds Oi ₁ -Due to appropriate investigation, possible cases can be found for an Instri the general rules for the described device that the estimated transverse diminution to multiply by 100 and then to cover it by the whole width of the attachment is to be divided by 4 and by the half approach by 2; if you voi quarter approach width is covered, the D indicate; if they are from. the eighth approach is covered, is to be multiplied by 2 and the sixz <starting width by 4. To make these calculations superfluous, the instrument is usually given a T added, which the estimated (dimensions and observed overdecki corresponding distances can be seen. Paτenτ claim: A rangefinder in the form of a multiple metal plate, the approaches of which α bc for a certain eye distance and a fixed distance corresponding to the same different units of measurement (meters, S man's width, etc.) are divided by notches. For this purpose ι sheet of drawings.