| 摘要 |
680,500. Secret telegraphy. GRETENER, E. Oct. 5, 1950 [Oct. 5, 1949], No. 24353/50. Class 40 (iii). A device for generating mark/space combinations which change in a complex manner, more particularly for enciphering purposes, employs a distributer the segments of which are connected to mark or space potential through an arrangement of contacts which are reset after each combination according to a preset programme. Thus in Fig. 3, transmitting relay 40 is operated from a distributer 31 having a set of segments I-XIV which are connected to the positive or negative terminal of battery 41 each through a change-over contact 44-57 and thence through a cascade connection of double-pole change-over switches 79-92. The contacts and switches are operated from cam wheels 58-71 and 93 which are reset on the completion of each rotation of the distributer by step-by-step gear 75 and gear train 76. The position of each individual cam wheel may be present by hand with the aid of friction clutches between the cam wheels and gears. The arrangement provides for a fourteen-unit code, a second set of five segments 34 being included for a five-unit code. Either set of segments may be selected by engaging brush 37 or 38. In a modification, Figs. 4 and 5 (not shown), the cascade of double-pole change-over switches is connected in a closed ring which is broken at a different point after each combination by a rotary switch device. In a further modification, Fig. 6 (not shown), the double-pole changeover switches are brought out to plugs and sockets which permit the switches to be connected in any desired sequence within two cascades. In Fig. 3, the contacts 24 of relay 40 are shown connected to encipher normal signal combinations set up on transmitting contact 21, the distributer 31 being run in synchronism with the transmitter 20. Contacts 21 and 24 are connected so as to effect the enciphering by a " multiplication of signs," that is like elements in the signal and enciphering code result always in a mark condition appearing on the output line 26 whereas unlike elements result always in a space condition. Thus as shown in Fig. 1, the enciphering of letter Y set up on contacts 21 by the combination corresponding to L set up on contact 24 results in letter O passing to line. At the receiving terminal 28 the signals are deciphered by a similar device 27 set up to operate in accordance with the same programme as that employed at the transmitter. Specification 673,618, [Group XXXVII] is referred to.
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