Patent GB-367424-A (GB)
Title: Improvements in or connected with coding and decoding machines
IPC: G09C3/00
Filed: 1930-11-18
Abstract: 367,424. Typewriters for coding and decoding. BUDD, J. G. H., 39, Fitzroy Road, St. Pancras, and FOSTER, B. E., 117, Babington Road, Streatham, both in London. Nov. 18, 1930, No. 34717. [Class 100 (iv).] Type-wheel machines; hammer-impression arrangements; letter-spacing mechanism; backspacing mechanism.-In a coding and decoding machine, a printing-wheel is subjected to a continuous turning-influence but is permitted to rotate in one direction only in accordance with the operation of a key and mechanism causing the character presented by the printing- wheel to be in advance of or behind the character appertaining to the key by a predetermined number of characters. The type-wheel 1 is .connected by worm-gearing 4, 5 and a friction clutch 3 to a continuously-rotating shaft 2, the clutch enabling the type-wheel to be stopped without stopping the shaft 2. The type-wheel 1 and worm wheel 5 form a casing enclosing sun-and-planet gearing, the sun wheels of which are secured to shafts 6, 7, and the planet wheels to the casing. The sun-and-planet gearing and gear-wheels 8, 10 .drive a drum 12 at the same speed as the typewheel. These parts are normally held from rotation by the engagement of a rocker 13 in a notch 14 in the drum. On depressionof a key 18, a bar 26 carried by a shaft 29 is rocked and removes the rocker 13 from the notch 14. Each key 18 has a projection 18a normally supporting a projection 17a on a corresponding member 17 pivoted on a shaft 19. In normal position, a nose 17c on the member 17 is held away from the drum 12, but on actuation of a key, the nose is pulled by a spring into engagement with the surface of the drum, and on rotation of the drum snaps into the appropriate notch 16. The parts are so arranged that, if no coding-mechanism were employed, the character on the type-wheel set in printing- position would be the same as that of the key actuated. When the nose 17c of the member 17 engages the notch 16, a pin 23 on the key lever is released from a notch 17b so that the key lever can be further depressed to rock the - shaft 29 and actuate the printing-mechanism through a crank 31, link 32, and slide 33. The shaft 7, through gearing 9, 39, drives a shaft 40 at the same angular speed as the type-wheel and moves a finger 41 over a board 42. The board is provided with nineteen apertures 43, one aperture corresponding to the " stop " position, and the remainder being arranged in two series each of nine equally spaced apertures. The apertures provide for the departure of the coded character by nine intervals before or behind the character of the key, and since the shaft 40 rotates in one direction only, the apertures in one series occupy the reciprocal position relative to those of the other series. Pegs carried by levers 44, 44a are arranged to project through the apertures 43, the levers being spring-urged or positively-operated to withdraw the pins, but rocked to project the pins by cams 45 on a shaft 46. The lever 44a actuates the peg projecting through the " stop " aperture and the levers 44 actuate the stops in the two series'. The cam shaft 46 is longitudinally movable to control the levers 44 by means of a lever 47 pivoted to a bracket 48 formed with two notches for retaining the lever in adjusted position, the lever 44a being provided with a wide face to co-operate with the corresponding cam in either position of the shaft. Alternatively, the two sets of levers may be mounted on adjustable pivots to enable either set to be moved towards or away from the cams. The cams 45 are adjustably mounted on the shaft 46 and may be arranged in any desired order and secured in one of six angular positions about the shaft to provide for the use of a six-figure code number. The cam assembly is made detachable or is constructed as in Specification 367,783, [Group XV], to facilitate adjustment. A knob 49 and a pointer 50 moving over a graduated dial are provided for facilitating setting of the cams. A ratchet wheel 38 is secured to the shaft 46 and is engaged by a pawl 37 on a slide 36 connected to the shaft 29, the arrangement being such that on depression of a key the pawl rides over the ratchet, but on the return movement, the shaft is rotated one division to set the next cam in operative position. When the machine is first set into operation, the shaft 6 is held against rotation by the engagement of the rocker 13 in the notch 14 of the drum 12. The shaft 7 commences to rotate until stopped by the engagement of the finger 41 with the stop set by the first cam, so that the wheel 1 is set forward or backward from the zero position according to the first figure of the code number. The key corresponding to the first character of the message to be coded or decoded is then depressed and so releases the drum 12 and causes the shaft 2 to rotate the type-wheel to a position in front of or behind the letter of the message according to the position of the finger 41. The return movement of the key resets the cam mechanism in order to bring the second cam into operative position and release the first stop. The downward movement of the key after it has been released by the notch 17b depresses the slide 33 together with an arm 51 carrying a pad 52 which presses a paper strip 59 on the type-wheel. The paper strip is fed from a spindle 60 through a guide 53 formed with an aperture to permit printing, by means of feed-rollers 56, the lower of which carries a ratchet wheel 57 rotated by a pawl 54 on the slide 33 during the return movement of the key. The type-wheel may be locked during printing by a pin entering one of a series of depressions therein. In order to enable a space to be inserted automatically after a group of any desired number of characters, the ratchet wheel 57 is formed with two series of teeth, similar, for example, to the ratchet wheel 65 shown in Fig. 3. The teeth of each series are equally spaced, but a gap of double the normal size is formed between the last tooth of each series and the first of the next. The long tooth of each series projects beyond the pitch circle of the remaining teeth and the inner position of the pawl 54 is determined by a stop. An ordinary space key 18c, Fig. 5, may be provided, preferably located adjacent the crank 31. The slide 33 is replaced by two bars 78, 79, connected respectively to the arm 51 and the pawl 54. The bar 79 is held in raised position by a spring 80 and is connected with the crank 31 and lever 18c by slotted links 82, 83 respectively. The bar 78 is connected to the crank by a link 81. When the crank is depressed by actuation of a character key 18, both bars 78, 89 will be moved downwardly to effect normal operation of the machine. Depression of the key 18c will draw the bar 79 down, but the pin 84 will slide in the slot in the link 82. To facilitate detection of an error and to provide a record of the message coded or decoded a second type-wheel is geared directly with the drum 12 without the interposition of the coding mechanism, and a second paper strip is fed by the rollers 56. The second type-wheel is mounted behind the wheel 1 and above the paper strip, and the arm 51 is extended beyond its pivot to effect both printing operations. To render the printed matter visible, the strips may be carried in a frame arranged vertically behind the typewheel, the frame being moved automatically towards and from the type-wheel, this movement being utilized for effecting the feed of the strips. To enable an error in typing to be obliterated, a key is arranged beyond the end of the bar 26. The inner end of the key is connected to a slide 64 having extensions 64a, 64b located on the side of the feed rollers 56 opposite to that occupied by the slide 33, and an extension 64c adjacent the type-wheel 1. The extension 64a carries a pawl 66 adapted to engage a ratchet wheel 65 on the shaft of the lower roller 56. The teeth on the ratchet wheel are arranged to effect backward, rotation of the roller 56 to the correct extent. The paper strip is not moved backward unless one of the extended teeth is in position for engagement by the pawl 66 as the upper roller 56 is raised by the engagement of the inclined upper end of the extension 64b of the slide with the end of a lever 67 carrying the roller. If an extended tooth is engaged by the pawl, the paper is fed backwards the distance of one toothdivision before the upper roller is raised. The extension 64c carries an ink pad 70 which is pressed into engagement with the paper through an aperture in the guide 53 in a position to' obliterate the last printed character. The lever of the obliterating-key, on depression, acts also on a bell-crank lever connected by links to a pawl engaging a ratchet wheel on the cam-shaft 46 in order to set the cams back to the position occupied before the incorrect character was printed. Specification 324,734, [Class 100 (iv), Typewriters &c.], is referred to.