Patent GB-309712-A (GB)
Title: Improvements relating to typewriting machines
IPC: G09C3/00
Filed: 1928-03-21
Abstract: 309,712. Ross, J. Smith-, and Paterson, J. G. March 21, 1928. Index type-wheel machines for coding and decoding; type-wheels.-A pair of type-drums, mounted on a single shaft or a pair of shafts adapted to be rotated and moved axially for typeselection, and to be swung for impression, are operated simultaneously by a relatively movable index-member and indicator, the type on one of the drums and the characters on the indexmember being adjustable in accordance with the code. In the machine shown in Fig. 2, typedrums 26, 27 and an index drum 28 are mounted on a horizontal shaft 29 journaled in arms 31, 32 which are splined on a shaft 34 journaled in brackets 38, 30. Type-selection is effected with reference to a stationary indicator 30 by turning and moving axially a knob 36, and impression is effected by depressing a finger-piece 37 on the arm 31. A spring 44 connected to an arm 43 on the shaft 34 elevates the type-drums on release of the finger, piece. The type-drums 27, 27 print on platens 14, 13 which are provided with knobs 15 and detents 16, and may be geared together. The carriage may be provided with letter-spacing of the kind described in Specification 278,277 and comprising a rack 22 co-operating with a pawl 23 coupled to the arm 43. The types on the typedrums and the character on the index-drum are arranged in five circumferential rows, the typedrum 27 being integral, and the type-drum 26 and index-drum consisting of a number of adjustable discs 52, 60 respectively. The discs 52 are clamped by a nut 55 and have pins 53, Fig. 4, for engaging holes 54 in the faces of adjacent discs. The discs 60 are mounted between flanges 61, 62 and have spring-balls 60, Fig. 6, for engaging notches in the adjacent discs. To code a message, the discs 52 are adjusted with reference to a mark 80 to represent the code and typing is effected in the above-described manner, the message being typed in code and clear by the type-drums 26, 27 respectively. For decoding, the discs 52 are adjusted in the above-described manner and the discs 60 are adjusted with reference to a mark 81, the coded message being typed in code and clear by the type drums 26, 27 respectively. The type-drums may be arranged side-by-side, the index-drum operating a rack geared to the type-drums, and the platens being arranged in tandem or a single long platen being employed. The index-drum and indicator may be replaced by a series of endless index-strips 87, Fig. 10, and a movable pointer 89 which is mounted universally in a standard 91 and is connected to a rack 92 engaging a pinion 94 on the shaft 29 of the type-drums. The rack passes through a strap 95 on the shaft, and by moving the pointer into register with a character on one of the index-strips, the shaft is rotated and moved axially for type-selection. The index-strips pass over rollers 8 and are arranged in a box 85 having a transparent cover 86, the rollers and indexstrips being withdrawn from the box for the purpose of adjusting the index-strips in accordance with the code. The index-strips may be replaced by a board having interchangeable index-characters. Aligning for impression.-The flange 61, Fig. 2, of the above-described index-drum 28 is toothed to co-operate with an aligning-plate on the base 11, and the flange 62 co-operates with teeth in the plate.