Patent GB-197763-A (GB)
Title: Improvements in or relating to apparatus for the production of cipher documents especially adapted for telegraphic despatch
IPC: G09C3/00
Filed: 1922-02-28
Abstract: 197,763. Fairweather, H. G. C., (Aktiebolaget Cryptograph). Feb. 28, 1922. Electric machines for coding and de-coding; space - key actions.-In electrical apparatus for the production of cipher documents such as that described in Specification 152,625, provision is made as described below for spacing the cipher into equal groups of signs and ciphering the space between the words of the clear text, typing alternately in cipher and spaced clear text, and returning the ciphering mechanism to a predetermined setting. A transmitting keyboard Tt operates a. clear copy typewriter T1t and a cipher typewriter T,t the latter through key - wheel devices and rotating commutator contacts C1, C2. Four key-wheels N1 - - - N4 operate solenoids S4, S5 for turning the commutators C1, C2, or producing no movement thereof if the electrical connections through a further key device V5 are broken. The key device V5 is mechanically connected with the armatures of solenoids S3<SP>1> - - S3<SP>4> which operates the discs N1 - - N4, and is given an arbitrary rotary movement. An arbitrary number of protruding contacts V2 are arranged around the periphery of the key-wheel V5 in a number of rows equal to the number of discs N1 - - N4 and these contacts are adapted to break the circuit between springs f1 - - f4 and a common contact V4, so that when this circuit is opened no movement of the commutator contacts C1, C2 can take place. Spacing into groups. For spacing the cipher into groups of five a spacing-key T2m is operated by a solenoid S2m after every fifth depression of a key Tt. This is accomplished by a disc N5 mechanically connected with one of the keydiscs N1 - - 4 and provided with a number of equally spaced projections on its periphery for closing a contact k11 ; five times the number of projections on the disc N5 being equal to the number of movements required to give the keydiscs N1 - - N4 a complete revolution. While the cipher is spaced into groups of five the clear text is spaced as written, a spacing-key Tm on the transmitting keyboard operating a spacing-key T1m on the clear copy typewriter through a solenoid S,m. The spacing-key Tm also excites the solenoids S3<SP>1> - - S3<SP>4>, and one of the cipher solenoids, for example S2x, so that a clear text space is ciphered and combined in the cipher groups of five. Clear and cipher text alternately. To transmit clear text or cipher alternately, the contact k1t of each transmitting key Tt is connected to a switch contact W<6>, and the contact k1m of the spacing-key Tm is connected to a contact W2. These contacts are thrown over to connect fixed contacts W7, W8 for cipher, and fixed. contacts W5, W6 for clear text on the cipher typewriter, the contacts W5 being connected to similar signs on the cipher typewriter as the transmitting keys operate on the typewriter Tt, and the contact W6 is connected to the spacing-key solenoid S2m. Switching-over W1, W2 from W7, W8 to W5, W6 is accomplished by a lever W having a projection p for engagement with notches in a disc L. The disc L is mechanically connected to the key-discs N1 - - N4 and the disc N4, and the number of notches is equal to the number of projection on the disc N5. The change-over from cipher to clear text cannot therefore take place until a group of cipher has been completed, indication of which is given by the lamp y. Returning commutator members to predetermined position. To return the commutator members C1, C2 to their original setting before commencing clear text, these members are provided with metal discs O1, O2 having insulating- sectors i1, i2. Contact springs f5, f6 and f7, f8 bear upon the discs O1, O2 respectively, the contact springs f6, f8 having a longer peripheral engagement with the discs O1, O2 than the contact springs f6, f7 so that one pair of contact springs is permanently in electrical connection with the discs, while the other is insulated therefrom when the sectors i1, i2 are underneath. The contact springs f5, f2 are connected to contacts contact W10 on the throw-over switch, and the contact springs f5, f7 are connected to contacts k9 k10 actuated by the solenoids S4, S5.