GB146432A - Improvements in or relating to periscopes - Google Patents

Abstract

146,432. Optische Anstalt C. P. Goerz Akt.-Ges. Jan. 19, 1916, [Convention date]. Periscopes more particularly for submarines. In order to use practically the whole of the space available in the vertical direction and also to allow for a convenient observation position for any desired vertical adjustment of the light admission opening. the tube carrying this opening is adjustably mounted on the instrument carrier in such a manner that its lower end can occupy a position below the eye-piece, the light being reflected from the adjustable tube towards the eye-piece by a reflector arranged below the eye-piece. For this purpose, the longitudinal movement of the tube may take place between two telescopic systems belonging to the instrument, or, if there are more than two such systems, between each two. Or the tube 4, Fig. 1, carrying the opening 3 may have an optical system of finite focal length and provision be made for simultaneous adjustment of the tube and the reflector 9, 10, so that the focal planes of the system in the tube and that of the eye-piece 8 always coincide. As shown in Fig. 1, this adjustment may be effected by screwed stems 11, 12, which are rotatably mounted in a plate 13 carrying the reflector, engage with nuts 20, 23 upon the fixed casing 21 and tube 4 respectively, and are simultaneously driven by a central gear-wheel 15, which is driven from a shaft 19 through the bevel and spur gearing 18, 17<1>, 17. By these means, the tube is moved at twice the rate of the plate 13. An airpressure equalizing chamber 24 is provided. In a modification, instead of four screwed stems being employed, two only are used, and their upper and lower halves are constructed with opposite threads to engage with the fixed nut and the nut on the tube 4 respectively. If the tube 4 has a telescopic optical system it can be raised in the usual manner without corresponding adjustment of the reflector being necessary; or, as shown in Fig. 8, the tube 38 with telescopic system 39 may be adjustable over the limb 42 of the fixed U- shaped casing carrying the reflector 45 and eyepiece 44, a second tube with telescopic system 41 being adjustable within the limb 42. In order to allow a sweeping of the horizon without the observer having to walk round the object-glass tube itself, this tube and a tube carrying the eye-piece may be geared together so as to rotate in the same direction, the U-shaped reflector casing participating in the longitudinal movement of the object-glass tube but not in its rotation.