Patent GB-743812-A (GB)
Title: Enciphering device
IPC: G09C1/12
Filed: 1953-08-17
Abstract: 743,812. Type-printing telegraphy &c. GRETENER, E. Aug. 17, 1953 [Aug. 19, 1952], No. 22642/53. Class 40 (3). [Also in Group XV] In an encyphering arrangement the key code by which the original message is modified to produce the cyphered message, is formed by the continuously permutated mutual position of a number of elements rotatable step-by-step, all of which elements have the same number of steps for one full revolution, and a numberof said elements is regarded as forming a sequence, and wherein the step-wise rotation of a respective element in the sequence is effected at any moment by control means directly dependent upon the momentary position of all preceding sequential elements of the sequences. The rotatable members 1 .. 9, which constitute the elements and co-operate to form the cyphering key, have a broken ring of cams 33, operating by springs, such as 34, contact pairs 11 ... 19 connected through a permutation device 46 of which five output leads are connected to segments 61 ... 65 of a distributer 60. Each of the members 1 ... 9 carries a ratchet wheel 31 engaged by a pawl 37 pivotally mounted on a pivoted lever 38, biased upwardly by a spring 40 and carrying a leaf spring 39 urging the pawl 37 towards this ratchet. A cam 41 on the shaft 42 of the distributer 60 is shaped to depress the lever 38 so that the pawl 37 engages a lower tooth, and the flat of the cam in combination with the spring 40 steps the wheel forward. The pawl 37 is formed with a toe-like armature 43 associated with a magnet 59 which, when energized, rocks the pawl 37 out of engagement with the ratchet so that the step movement of the member 9 is temporarily suppressed. The operation of a feed-suppression magnet of the group 52-59 associated with members 2 ... 9 is dependent on the simultaneous closure of all switches 21 ... 28 respectively operated once only during a revolution of the wheels 1 ... 8 by the cam 35 in each rotatable element. The key code which is passed as a series of impulses from terminals 69 by the segments 61 ... 65 of the distributer 60 is dependent upon the selective setting of those contact members 11 ... 19 which, via the permutation switch 46, are at the time connected to the five live segments of the distributer. The four additional outputs from the switch 46 are connected via leads 70 and switches 71 ... 74 which, in the operated position, as indicated for switch 73 and magnet 56, connect magnets 54 ... 57 via switch 46 to an individual contact member 11 ... 19. In a modification, Fig. 2 (not shown), the stepping of the wheels 1 ...9 is effected directly by the armatures of the magnets, such as 52 ... 59, of Fig. 1, and the stepping of a wheel is interrupted solely when switch members associated with preceding wheels in the sequence have been operated. As in the arrangement of Fig. 1, four output leads from the permutation switch are individually connected via manually-operated switches to the operating circuits of the magnets, so that the operation of such magnets is controlled by the position of the contact members 11 to 19 of Fig. 1, in combination with the connections through the permutation switch. In a further modification, Fig. 3 (not shown), the wheels 1 ... 9 are stepped directly by the magnets as in Fig. 2, five of the magnets operating in dependence on contacts closed by all preceding wheels of a sequence and four of the magnets being controlled by output leads from the permutation switch with operating potentials selectively determined by contact members such as 11 ... 19 of Fig. 1 and four other contact members operated by a second ring of cams on the associated wheels: Specification 680,500 is referred to.