Patent GB-191407570-A (GB)
Title: Improvements in or relating to Cryptographic Typewriting Machines.
IPC: G09C3/00
Filed: 1914-03-25
Granted: 1915-06-24
Abstract: 7570. International Electric Co., [Mix & Genest Akt.-Ges.]. March 25. Machines for coding and decoding ; type-wheel actions.-Code mechanism 4 is carried beside the platen 3 on the papercarriage 2 of a type-wheel machine and i m p a r t s variable rotation to the type-wheel, in addition to the normal rotation for character selection, in accordance with the position o f the code mechanism as the carriage advances. The variable movement is imparted to the type-wheel in the spacing movement after impression, giving a new initial position for the next character selection. The type - wheel action comprises a serrated sliding member 28 actuated by the key-levers 35 and co-operating with a rack 26 engaging a pinion 25 on the type-wheel spindle 21 for character selection, and a universal bar 30 engaging a lug 29 to swing the type-wheel for impression. The rack 26 is formed on a bar 48, which is formed with a second rack 27 engaging idle gears 51, 52 on the member 28, and is loosely connected to a rack 38 by means of bent-over ends held together by a spring. The rack 38 communicates the variable movement through the rack 26 to the type-wheel, the rack 38 being retracted by a spring 39 to an amount determined by a feeler 44 geared to the rack and advanced against the code mechanism ; the paper-carriage 2 is provided with slots 107 for the passage of the feeler. When a key-lever is depressed, a latch 86 is tripped to lock the gear 52, so that the rack 26 is coupled to the member 28, and is withdrawn at the end of the down-stroke of the key-lever, so that the variable movement can be imparted to the rack 26 in the return movement of the universal bar 30. The latch 86 is normally held up by a bail 87 supported hy a lug 94 on a spring-pressed lever 93. An arm 102 on the universal bar 30 co-operates with a trip-piece 98 on the lever 93 to release the latch, and the trip-piece 98 engages a stop 99 to release it from the arm 102, so that the latch is withdrawn ; the arm 102, in its return movement, also returns the member 28 by means of inclines 105, 106, and finally re-engages with the trip-piece 98. The code mechanism consists of a series of pairs of connected ciphering and deciphering disks 9, 10, adjustable between end dicks 8 on a shaft 7 and secured in adjusted position by means of a rod 12 passed through holes 11. The disks 9, 10 are formed with peripheral steps 13 for co-operation with the feeler 44. The shaft 7 is adjustable longitudinally into two positions, determined by stops 14, 15, to bring either the ciphering-disks 9 or the deciphering-disks 10 into operation. The shaft 7 can also be rotated to vary the code, praferably at the beginning of each line, according to a code word displayed in succession by letters on one of the end disks 8 through an aperture in a casing (not shown). Rotation of the shaft 7 is normally prevented by means of a detent-wheel 81 engaged by a stop-member 80. A key 67, through a connexion 72, withdraws the stop-member 80, and also simultaneously withdraws the feeler 44 from the stepped disks and clear of the papercarriage by engagement with a lug 66, and withdraws a detent pawl 74 from the carriage rack 77 to permit return of the carriage. The universal bar 30, in its return movement, effects in known manner the spacing movement of the papercarriage, and also withdraws the feeler 44 through the lug 66, by connexion with a lever 60 car ying a spring pawl 65, which finally slips off the lug 66 to allow the feeler 44 to ascend into engagement with the next disk now brought into position by the spacing movement.