USection III. ELBOW TELESCOPES

TM 9-258

b. The optical system of this articulated

target image. After passing through the prisms in the

articulated joint, the inverted image is erected and

telescope forms an inverted image of the viewed target.

projected by the power lens erecting system through the

One of the two reticle patterns is projected into the

offset prisms to the eyepiece.

optical train of the telescope by the beamsplitter and

appears

superimposed

the

Section III. ELBOW TELESCOPES

c. There are elbow telescopes of a number of

8-8.

General.

designs differing in components of the optical system,

a. The elbow telescope is used wherever it is

necessary to direct the line of sight through a 90ƒ angle.

method of mounting, and other details depending upon

the purpose of the instrument. The specific instruments

This is desirable where the range of the angle of

described herein are typical of those designed for

elevation of the instrument is considerable. Telescopes

different purposes.

of this type are used to permit observers to assume the

most convenient positions for the operation of their

8-9.

Typical Elbow Telescopes.

instruments. Such telescopes are employed in the

a. The elbow telescope illustrated in figure 8-9

pointing of recoilless rifles, towed and self-propelled

is typical of those designed for direct sighting in elevation

howitzers and guns for tracking the target and fire, and

as a part of a two-sight, two-man system of the howitzer.

for other purposes.

b. An elbow telescope is essentially the same

It has 3X magnification, 13 20 minutes field of view, and

has a combination reticle graduated for use with two

as a straight tube telescope except that an erecting

types of ammunition. The elbow telescopes of this

prism (e.g., Amici) may be used in the elbow to erect the

image and also produce the 90ƒ deviation. This

series are of the fixed focus type, are not provided with

filters, have two reticle illuminating windows, an

eliminates the lens erecting system and shortens the

instrument light adapter, and are identical except for

optical system. The schematic diagram of one type of

differences in reticle patterns (fig 8-9).

elbow telescope is illustrated in figure 8-8.

Figure 8-8. Schematic diagram of elbow telescope.

8-5