| 摘要 |
817,761. Secret type-printing telegraphy. HELL, R. Oct. 28, 1955 [Jan. 26, 1955], No. 30914/55. Class 40 (3). In an arrangement for producing ar extended cipher control strip from an existing strip carrying a random sequence of code combinations of binary elements, the latter are recorded on a number of storage devices equal to the number of elements in a code group of different capacity, the largest store being capable of storing a number of elements equal to the number of code groups in the existing cipher strip, and the numbers of elements stored in the devices being prime to one another, and stored elements from the respective devices are read off and simultaneously presented to a discriminating circuit which, in response to the detection of a predetermined code combination, controls a device to record on a tape or strip, forming the extended cipher strip, a code combination derived from an arbitrary sequence of combinations of binary elements which are applied to the recording apparatus in the same time sequence as the elements recorded from the original cipher strip are presented to the discriminating device. The pulses derived from an intermittently fed cipher strip 21 are applied by an amplifier 23 as D.C. or A.C. pulses to recording heads 24 ... 28 co-operating with a ferro-magnetic layer on the circumference of the discs 1 ... 5. The disc 1 has a number of circumferential divisions or recording positions corresponding to the number of code groups in the strip 21, and the numbers of the divisions in the discs 2-5 are progressively less, all the numbers being prime to one another. The ratios of the gear-wheels 7 ... 11 and 12 ... 16 are such that the discs 1 ... 5 simultaneously rotate through an equal number of element divisions. Impulses simultaneously detected by pick-ups 29 ... 33 are fed to a discriminator device 34 arranged to respond solely to a predetermined combination to provide a triggering pulse to a device 39 which punches a tape 40 in accordance with a five-unit combination derived by feelers 38 from discs 35 rotated by gears 36, 37 from the rotatable shaft 17. The transverse holes or recordings on the discs 35 correspond to the five-unit code and the discs 35 are moved from one position to the next in a time equal to that taken by an element on the discs 1 ... 5 to pass a pick-up or recording head. The perforated cipher control strip 41 and the strip 44 perforated according to the plain text of the message are fed simultaneously to a twin head 42 producing an output perforated strip corresponding to the multiplicative combination of the elements represented by the perforations appearing on the two strips 41, 44. |
