Patent GB-146991-A (GB)
Title: Telegraphic ciphering and deciphering mechanism
IPC: H04L9/38
Filed: 1920-07-06
Abstract: 146,991. Western Electric Co., (Assignees of Parker, R. D.). Dec. 9, 1918, [Convention date]. Addition to 146,520, [Class 40 (iii), Telegraphs &c.]. Ciphers.-A ciphered message in perforated strip or printed form is produced by the conjoint action of two perforated strip machines through one of which the unciphered message is passed simultaneously with the passage through the other of a "key" strip. The first strip machine may be replaced by a keyboard. The ciphered message is transmitted to a distant station and deciphered by passing it in perforated strip form through a machine simultaneously with the passage of a "key" strip through a second machine, these machines operating conjointly to produce the deciphered message in printed form. When the ciphered message is transmitted electrically it may be transformed into morse before transmission and reproduced as perforated strip at the receiving-station. A keyboard A, operated in accordance with the unciphered message, controls selectively contacts 1 .. 5 or a strip perforator p in the usual manner. A tape machine B the contacts 1<1> .. 5<1> of which are controlled by a ''key" tape 11 operates in conjunction with the keyboard A or a tape machine B<1> supplied with tape from the perforator p to control the punches of a cipher perforator P or the selecting-magnets of a printer Q which prints the cipher message. When the keyboard A operates in conjunction with the machine B the switches 48, 34 and 37 are moved to the positions shown. A universal bar 29<1> of the keyboard A operates a switch 30 at each depression and release of a key to energize a punch magmet 28 of the perforator P or the printing-magnet 56 of the printer Q and a tape-feed magnet 12 of the machine B. When the machine B operates in conjunction with the machine B' the switch 48 is moved to its upper position and the switches 34, 37 and 41 are moved to their dotted positions whereby a timing switch 44 controls the tape-feed magnets 12 and the switch 45 the punch magnet 28 or printing magnet 56. The ciphered message on the tape 29 may be passed through a transmitter, or it may be transferred to morse before transmission and converted again into perforated strip, or it may be sent by mail. The machine B is rendered inoperative by opening switch 38 and grounding its bus-bar 10 at switch 49. If the "H" key of the keyboard A be depressed or the "H" perforations are passing through the machine B<1> at the same time as the "G" perforations are passing through the machine B the magnets 22, 23 and 24 of the perforator P are energized to punch the tape 29 in accordance with the letter C. If the tape 29 be passed through the machine B' at the same time as a key tape similar to the one employed in setting up the cipher message is passing through the machine B and the perforations on the tapes are in the same phase the magnets 53 and 55 of the printer Q are energized to print the letter H. In a modification, the relays controlling the perforator P and printer Q are placed between the leads 26 and 27 and the timing switches are replaced by a distributor switch.