GB189816052A - Improvements in or relating to Ciphers and Cipher Writing. - Google Patents

Abstract

16,052. Boult, A. J., [Ferrari, C. E.]. July 22. Type - writers for secret writing. Relates to a particular construction of cipher, and to a cryptograph and a type-writer for use in writing or translating the cipher messages. The principle of the code is that two alphabets are employed, one for the letters of the message and the other for the signs or letters to represent them in the cryptogram, which are shifted relatively to one another according to some predetermined system after each letter or sign is written. Fig. 6 shows a plan of a type-writer for use in writing cryptograms according to this system. Two bars or frames C are employed beneath the right and left hand keys, each provided with projections F which act upon the arms of two conico-circular racks D secured to the shaft B. The cylinder B' is formed with slots in which are adjustable slide blocks arranged to regulate the movement of the double-armed lever b<2>, the backward extension of which enters the slots. The cylinder B<1> is rotated by suitable mechanism, so that the lever b' enters each slot in turn. Two drums A, X are employed, each provided with as many hammers s as there are keys, and connected by the rack Y. On depressing a key, the rod E lowers the levers h<1> and b<2>. The finger b<3> turns one of the racks D<1>, causing the drum X to rotate to an extent governed by the position of the slide block in the particular slot of the cylinder B' in which the lever b<2> happens to be. By continuing to press the key it acts to turn the drums A, X together by means of the rack Y. The hammer of the drum A will print the letter corresponding to the key operated, while the hammer of the drum X prints the letter which corresponds to it in the cipher message.