Patent GB-453660-A (GB)
Title: Improvements in or relating to machines for enciphering and deciphering messages
IPC: G09C3/00
Filed: 1935-04-03
Abstract: 453,660. Typewriters for ciphering. O'BRIEN, M. C. M., 1, Mays Hill Road, Shortlands, Kent. April 3, 1935, No. 10358. [Class 146 (ii)] [See also Group XVI] A typewriter for ciphering and deciphering comprises a number of cipher wheels rotatable about an axis which is adapted to be rocked automatically to bring the cipher wheels into engage ment with mutilated gear-wheels, rotatable on a fixed axis, during the return movement of a carriage and out of engagement at the completion of the return movement. The machine, which is of the kind described in Specification 320,315, [Class 100 (iv)], is provided with a "scatterdrum " formed of a number of discs 51, keyed to a hollow shaft 50, Figs. 2, 8 and 11, which also carries a gear-wheel 60 and a series of discs 49. Arranged symmetrically or otherwise around and parallel to the shaft 50 and passing through the discs 49, 51 are shafts 55, to each of which is pinned a gear-wheel 86, and each of which carries one or more gear-wheels 87, these gear-wheels being accommodated in recesses in the discs 49, 51. The gearwheels 87 are slidable along the shafts so as to be positioned in any of the discs 51. The discs 49 support rings 63 having internal teeth and each engaging with one of the gear-wheels 86, and the discs 51 support rings 79 each engaging with one of the gearwheels 87. Rotation of one of the rings 63 for the purpose of setting up a code-word or the like bv means of letters or other symbols on their peripheries therefore causes rotation of certain of the rings 79 according to the number and position of the gear-wheels 87 on the corresponding shaft 55 ; the rings 63 are however arranged to be disengaged from the gear-wheels 86 if desired to avoid disclosure of the code-word. The shafts are arranged to be locked in adjusted positions by means of a disc 66 carrying teeth each adapted to engage with one of the gears 65 secured to the ends of the shafts, the teeth being normally held in engagement by a spring 74, but being removable and held in disengaged position during adjustment. The rings 79 are each provided with a gapped flange 80 and a ring 82 formed with a mutilated gear 83 and a series of cams 84. The gears 83 co-operate with corresponding gear-wheels 110, Figs. 7, 8, and 11, attached to a series of cipher-wheels 109 rotatable on a shaft 108 carried by a frame 101 which is adapted to oscillate in the machine about a shaft 107 to bring the gears 83, 110 into engagement. This oscillation is only effected when a handle 169 is grasped by the operator to return a carriage 174 at the end of each typing run, the carriage being fed towards the rear of the machine after each depression of a key in the keyboard. The handle 169 first rotates until it is stopped by a pin and in its rotation a cam 167 thereon rocks a lever 123 connected to a bar 120 which is formed with cam surfaces engaging rollers 118, 119 on the frame 101. The frame is held in rocked position by a pawl 126 engaging a notch 125 until the carriage has reached the forward position when a bar 116 is moved by a projection 170 on the carriage and causes a protuberance 129 to release the pawl. Movement of the bar 120 also rocks a lever 121 to cause a gearwheel 161 to connect the gear-wheel 60 to a gear-wheel 162 secured to a worm 122 which is engaged by gearing on the underside of the carriage 174, so that return of the carriage rotates the " scatter-drum " and the cipherwheels. The cipher-wheels are normally held against rotation by detents 139 pivoted to levers 136 and having extensions 140 to engage the cams 84, the arrangement being such that the extensions are released by the cams in time for the gear-wheels 110 to be rotated by the teeth of the mutilated gears 83 to effect the resetting of the cipher-wheels. Depression of a key 300, Figs. 16, 17, 18, in the keyboard causes the lowering of a pin 352 engaging an oblique slot 351 in a lever 349 so causing this lever to rock and to rock a shaft 147, the shaft being locked in rocked position by a catch 358 which has been permitted to fall by a lever 354 engaged by a spindle 305 raised by depression of a key 300. The shaft 147 carries cams 146 controlling the movement of a frame 141, Figs. 7, 8, and 11, also pivoted on the shaft 107. The frame carries, at its upper end, a square shaft 143 on which is slidable a gear-wheel 144 adapted to engage one of the gear-wheels 110 according to its position under the influence of a fork 278 carried by the frame 174. The shaft 143 also carries a non-slidable gear-wheel 148 which is adapted to engage, when the frame 141 is rocked, with a gear-wheel 152 mounted, in association with a wheel 151 adapted for printing the message in plain language, on a shaft 150 rotated to an extent dependent on the key depressed. The rotation of the shaft 150 is timed not to take place until the wheels 144, 148 have been engaged with the wheels 110, 152. Rocking of the frame 141 causes rocking of a square shaft 153 carrying a triangular member 154 movable with the wheel 144 and rocked by the shaft to engage the upper end of the levers 136 and disengage the detent 139 from the corresponding cipher-wheel. Stops 394 adjacent the upper ends of the levers 136 prevent rocking of the member 154 except when thewheel 144 is in position to engage a gear wheel 110. The depression of a key rocks one of two levers 314. Figs. 16 and 17, according to the position in the keyboard of the key depressed, and the lever 314 moves in a slot 316 in a quadrant 317 to allow of lost motion while the frame 141 is rocked, and then rotates the quadrant which is in gear with a wheel 149 on the shaft 150. The quadrant is stopped by the engagement of its tail 321 with a pin 320 raised by the depressed key. The lever 314 engages a member 322 on the quadrant, and further motion of the lever after the tail 321 has engaged the raised pin 320 is permitted by springs 324. The lever 314 rocks a corresponding dog 325 to permit the movement of a projection 327 on the under - side of the tail 321. A shaft 333 is also depressed by the depression of a key, and draws downwards a lever 334 having a tooth engaging a projection 335 on a lever 228 normally held raised by a spring 230 on a bent shaft 225. The shaft 225 carries a pin 224 which, when the lever 228 is depressed, turns a square shaft 217 to raise a hammer 214, Fig. 8, over the typewheel 151 and a hammer 215, Fig. 11, which moves with the carriage over the cipher-wheels 109. The hammers are normally held raised above the paper strips by springs. At the end of the downward movement of a key, after the other movements have been completed, an extension 336 of the lever 334 strikes a screw 337 and rocks the lever out of engagement with the projection 335, so that the spring 230 rotates the shaft 217 rapidly and causes the hammers to effect an impression. In order that the parts may not be returned until the key has been completely depressed and an impression made, a spring-pressed tooth connected to the lever 334 engages a rack 341, and is only released from the rack to permit return movement when the lever 334 is rocked by the screw 337 ; it is prevented from re-engagement with the rack until the return movement of the lever 334 is completed by the inclined upper end of the lever engaging the projection 335. On the return movement of the key, the actuated lever 324 first permits the lost motion of the member 322 to be made up, and then returns the quadrant to normal position to reset the gear-wheels 148, 144, type-wheel 151 and cipher-wheel 109. The dog 325, which was not rocked, stops the tail 321 of the quadrant in correct position, and rebound is prevented by the dog previously set being returned to normal position by the lever 324. The pin 320 is allowed to descend, and, near the end of the movement of the key, the lever 354 raises the catch 358 and permits the lever 349 to return to its original position thus rocking the shaft 147 and permitting the frame 141 to return to its original position under the action of springs 372 ; a positive return may be provided, consisting of a tappet 376, Figs. 8 and 11, on the shaft 147 engaging a projection 373 on the frame 141. When the shaft 147 returns to its original position, an arm 208, Fig. 13, thereon engages a pawl 205 pivoted to a lever 202 and prevented from movement in one direction by a stop 210, the result being that the lever is rocked against the action of a spring 204 to release a lever 199 on a shaft 396. The shaft carries a spring-pressed arm 197 pivoted to a bar 189 supported on pins 196, Fig. 15, by inclined slots 195 so that forward movement of the bar causes it to be raised for the purpose of raising a pawl 190 suspended therefrom out of engagement with the flanges 80 of the " scatter-drum." The carriage 174 therefore moves towards the rear of the machine under the influence of a spring, thereby rotating the worm 122 which carries at its rear end a cam 211 engaging a projection 212 on the arm 197 so that the shaft 396 is rocked into position to be locked by the lever 202. This causes the bar 189 to be reset so that the pawl 190 is in position to engage the next flange 80 which does not present a gap to the pawl. At the conclusion of its rearward movement, the carriage 174 rocks a lever 382 to push forward, against the action of a spring 388, Fig. 16, a rod 384 carrying a projection 391 which is thereby caused to extend over a disc 393 secured to the spindle 305 so that depression of a key in the keyboard is prevented, and two impressions from the last cipher-wheel cannot be made. The ink-ribbon is fed from a reel 231 over the wheels 151, 109 to a winding-on bobbin actuated from a lever the upper end of which engages a notch 240 in the lever 123 so that the ribbon is fed forward at the completion of each typing run of the carriage. The message is typed in plain language on a strip of paper fed from a container 242, Fig. 8, supported on the