Patent GB-191512001-A (GB)
Title: Improved Apparatus for Changing a Series of Signs of any Length into another Series of Signs the Individual Signs of which are Arbitrarily Disposed as Compared to their Positions within a Standard Series.
Inventor: DAMM ARVID GERHARD
IPC: G09G3/00
Filed: 1915-08-19
Abstract: 12,001. Damm, A. G. Aug. 19. Ciphers and codes.-Relates to means for producing ciphers by changing a series of signs, such as the letters of a word, into another series of irregularly displaced signs, the change being effected by two or more co-operating mutation series or " keys." In the construction shown in Figs. 1 and 2, a disk 3 and a drum 2 mounted on a spindle 1 are marked out in squares bearing signs, such as letters, arranged on the drum in the same order in each row, but the same sign being advanced one step in each succeeding row. The signs on the drum are read through irregularly-arranged holes 17 in a band 16 with side holes to gear with pins on two loose interconnected rings operated by ratchet-wheels 7, 8, the teeth of which correspond to the squares on the disk 3. In using the apparatus, the disk 3 and drum 2 are turned until the sign on the disk 3 corresponding to the sign to be changed is opposite an observation slot in the cover of the apparatus; then an operating-arm 32 is moved forwards and backwards so as to cause the band 16 to be moved one step and bring a selected hole 17 under the observation slot and expose the sign selected on the drum 2. The operation of the band is effected in one direction by a pawl 9 acting on the ratchet-wheel 7, and in the other direction by a pawl 10 acting on the ratchet-wheel 8. The pawls, which are mounted on one spindle, are brought into operation alternately at irregular intervals by a chain 19 with irregularlyarranged projections 20 adapted to lift a pivoted arm 21 connected by a link 13 to the pawl 9. The operating-arm 32, in moving forward, operates the pawl one step, and in its backward movement operates the chain drum 18 one step through the arm 31 and the gearing shown. Instead of operating the chain drum directly, its operation may be effected through one or more similar chains, so as to produce the combined influence of three or more mutation series. In a modification, the disk 3 and drum 2 are replaced by a disk with radial series of signs, and the band 16 is replaced by a disk with irregularly-arranged openings, the step-by-step operation being effected through gearing from a star-wheel operated alternately in opposite dirctions at irregular intervals by two studwheels brought into and out of gear alternately by irregularly-disposed projections on a chain. Figs. 6 and 7 show an arrangement in which the sign selected on the drum 71 is exposed by depressing the key 109 marked with the sign to be changed, the keys being connected to shutters 114 normally covering the exposure aperture 116 in the cover. Depression and release of each key also operate the drum 71 and the chain 94 one step through the pivoted frame 87, the toothed sector 86, the toothed wheel 85, and the ratchet mechanism shown. The operating star-wheel 72 is rotated alternately in opposite directions by pin-wheels 73, 74, into and out of engagement with which it is slid alternately by a lever 92 operated by the projections on the chain 94. In another modification, the signs of a standard series are marked on a slide arranged in the cover of the apparatus and having at one end an opening to expose and read off a selected sign on a band passing over a drum and rollers inside the apparatus. The drum is rotated and the band moved one step on pulling out the slide to its full extent, the slide being connected by an operating-cord to a spring drum with a clutch to drive the operating-gearing, which includes reversing-mechanism controlled by a chain similar to those described above. To chango a sign, the slide is first pulled out to its full extent and then pushed back until the sign is opposite an index on the casing; the selected sign on the band then appears at the opening in the slide. In the construction shown in Figs. 6 and 7, the selected signs may be printed or rendered audible or visible at a distance electrically. For this purpose, the signs on the drum are replaced by electric contacts 161, Fig. 12, adapted to complete electric circuits through switch levers 163 connected as shown to the keys 109, so that on depressing one of these keys, the circuit is completed through the controlling-circuit of the device for printing the sign selected or giving the selected audible or visible signal. Studs 161 corresponding to the same sign are connected together and to the same conducting-wire. The conducting-wires pass through the drum axle and are wound a few turns on a pulley on this axle so as to prevent them from being twisted by the motion of the drum.