Patent GB-177518-A (GB)
Title: Improvements in apparatus for the enciphering of code expressions, represented by groups of figures, into pronounceable groups of letters, and for the deciphering of thelatter
IPC: G09C1/08
Filed: 1922-03-21
Abstract: 177,518. Aktiebolaget Cryptograph. March 24, 1921, [Convention date]. Index type-wheel machines for coding and decoding.-In ciphering and deciphering apparatus recording in print two-letter syllables always composed of consonant-vowel or vowel-consonant representing the cipher of two-figure groups, or vice versa, a scale of adjustment is provided, one part for ciphering letter groups comprising four series of figures, two containing ten different figures arranged in arbitrary order and two containing five figures each different in respect to one another, and the other part for ciphering figure groups comprising four series of letters, two containing ten different consonants and two containing five vowels in the same order. Eight type-wheels are provided, four bearing letter types and four bearing figure types, the letter type-wheels being adjustable according to the figure scales, two carrying ten consonants in reversed order, according to the ten figure scales, and two carrying five vowels repeated twice in reversed order with respect to one of the vowel scales, according to the five figure scales, and the four figure type-wheels being adjustable upon the letter scales, two according to the ten consonant series, both type-wheels ,carrying the same figure tvne in reversed order, and two according to the five vowel series, each type-wheel carrying five different figures repeated twice and arranged in reversed order with respect to one of the five figure scales. As shown, indicators 11 movable along slots 3 - - 10, provided with scales of adjustment as described, actuate levers 12 - - 19 mounted on ratchet sectors 20 - - 27 rotatable on a fixed shaft 28. Other sectors 30 - - 37 fixed to the hubs of the sectors 20 - - 27 bear types arranged as described, and are operated by levers 40 carrying spring pawls 39, all the levers being connected together bv arms 41 to a common bar 42. After a type-sector has been set according to the scale of adjustment, an arbitrary movement is given to it as follows. Nine curved arms 47 rotatably mounted on an axle 45 are each provided with a catch 48 for individual engagement with a fan-shaped member 52 comprising stepped elements swinging on the main shaft 28. The upper ends of the curved arms are guided by slotted members 55 which also serve as a stop for the member 52. The member 52 is rigidly connected to the bar 42. Two discs 57 are connected by nine rods 58 which carry rollers 59, the rollers being adjustable in position and operate to keep one or other of the curved arms 47 depressed, so that on moving the driving-lever 43 downward, the member 52 is given a movement of one to nine division on the type-sector according to the position of the rollers, the type-sector being thereby given a corresponding arbitrary movement. The two discs 57 and rollers 59 forming the cipher key are arbitrarily and automatically set by two ratchet-wheels 60, 61 engaged by a pair of pawls 62, 63 spring-pressed together, a roller 69 between the pawls being actuated by a chain 74 composed of segmental and flat links in any order. The segmental links in engaging a roller 72 reciprocate a rod 71 which carries the roller 69. The chain 74 is driven one link at a time by a projection 78 on the driving-lever 43 operating through a two-armed lever 80, bar 81, universal coupling 82, rod 83, two-armed lever 84, ratchet-wheel 88, and prism 86 around which the chain passes. Two arms 89 connected by a rod 90 and spring-connected to the frame bear upon the ratchet sectors returning these and the type-sectors to their idle position when the driving-lever is elevated, this elevation lifting the curved arms 47 and allowing the member 52 to be returned, and also freeing the pawl 39 when the pin 96 on linkage 95, 97, 98 is brought forward bv the toe 102 contacting with and depressing the connecting-rod 100. In the idle position of the ratchet sectors, the pins 96 engage well home in the recesses 93 of the pawls and allow them to engage the sector teeth. The line of cipher is brought into position vertically above the main shaft 28 and printing is effected in known manner. Specification 12001/15 is referred to.