GB538309A - Cryptographic typewriter - Google Patents

Abstract

538,309. Typewriters. AXE, E. C. (Carew, P. T., and Werner, W. F.). Jan. 26, 1940, No. 1615. [Class 100 (iv)] Type-lever machines for. ciphering; keys. In an. electric typewriter, the keys close the circuits of individual solenoids for actuating typelevers, and manually operated means is provided for readily transposing the solenoid-circuits to provide for ciphering. The paper-carriage is provided with electrically operated letter-spacing mechanism. In the machine shown in Fig. 1, the keys 1 close contacts 8, 9 to complete the circuits of individual electromagnets 18 connected to type-levers 2, the circuits including rings of contact-points 17 co-operating with contacts 15 on rings 14 on a drum 3 which is adjustable to change the cipher, or for deciphering. The drum may consist of a number of longitudinal sections which are separately adjustable by means of knobs arranged at one, end of the drum and connected by nested sleeves to the sections. The contacts.8, 9 may be replaced by a contact 34, Fig. 6, on the key 33 or key-stem, and a. ring of contacts 35, the key and stem being rotatable to select one of the contacts. The key is provided with a pointer for reading a dial. The solenoids may, as shown in Fig. 13 consist of coils 104, 105 having a single winding 106 and a double winding 107, 108 respectively. The core consists of a shell 113 containing iron discs 114, 115' separated by non-magnetic discs 116, the discs 114, 115 being formed with oppositely disposed radial slots 117, 118 respectively. The core is connected by rods 119, 110 to a typelever 120 and a returning-spring 112. The circuits may be so arranged that the core 105 is initially energized, and the core 104 is subsequently energized through contacts 109, 111 closed by the rod 110. Letter-spacing and carriage-returning mechanisms. A carriage 45, Figs. 1 and 4, for a platen 46 is provided with a rack 64 co-operating with a feed-pawl 66 carried by a lever' 67 which is operatedrby a solenoid 69 when any keys 1 or the space-bar 11 is depressed. A spring-urged detent 76 co-operates with the rack to hold the carriage. At line-end, a projection on the carriage closes contacts, a, solenoid: 77 is energized, the core 78 thereof releases the pawl 66 and detent 76, and the carriage is returned by means of the spring drum. Line-spacing mechanisms. On return of the carriage 45, Figs. 1 and 4, the platen 46 is automatically rotated for line-spacing by co-operation of a ratchet-wheel 51 with a pawl 52 on a lever 53 resting on. another lever 56 which rides over a stationary cam 58. The platen may be geared to a feed-roller 47 for a web 43 supported by the carriage.