Patent GB-190005890-A (GB)
Title: Improvements in and relating to Type-writing Machines.
Inventor: BLICKENSDERFER GEORGE CANFIELD
Filed: 1900-03-29
Granted: 1900-06-30
Abstract: 5890. Blickensderfer, G. C. March 29. Type-writers.-Relates to machines for writing in cipher, the invention being specially characterised by the provision of devices intermediate to the index-dial and typewheel, which automatically and irregularly change the relation between them, so that the frequency or relation of the printed characters affords no key to the cipher. The machine is shown in perspective veiw in Fig. 1. A bifurcated pillar b, rising from the base-plate a, constitutes a guide for a vertically-reciprocating plate c which carries the dial-plate 85 and typewheel 13. Lugs d receive the feed-bar or baseplate e of the paper carriage, which is provided with escapement feed-mechanism operated whenever the plate f is drawn forward, either by the handle g or by the bell-crank lever h. The horizontal arm of the lever h is in contact with a stop j on the plate c, and is actuated each time the plate c is lowered. In operating the machine, the dialplate is adjusted by means of the knob 87 so as to bring the desired character beneath the detent y. The hand-lever is then depressed, the first effect being to move a slide carried on the plate c so as to cause the descent of the detent y, which locks the dial-plate accurately in position.- The plate c then descends, and the type-wheel moves the inking- roller i out of its path, and prints on the paper a character which depends on the angular relation between the type-wheel and dial-plate existing at that moment. The type-wheel is mounted on a shaft 12, Fig. 6, capable of longitudinal movement for printing upper-case characters. A hub 83 is also secured to the shaft 12, and is provided with a crank-pin 81 which engages with the " pin-disc " 54, Figs. 6 and 13. The pin-disc bears characters on its edge, and is provided with sliding pins 60 which can be set so that any desired combination of them will project rearwardly as shown in Fig. 13, such combination constituting a key to the cipher. The dial-plate 85 turns freely on the shaft 12, but engages with an arm 39, Figs 6 and 13, so that the plate 37 turns with it. The plate 37 supports a shaft bearing at one end the segmental pinion 33 and at the other an escapement device which cooperates with the pin-disc 54. The escapement consists of a dog 41, Fig. 15, and a recessed stud 53. Each time the plate c is depressed, a spring within the hub of the pin-disc 54 is wound up, and during the upward or return movement of the plate c the ratchet-wheel 29 is turned so as to rotate the pinion 33 and allow one of the pins 60 to pass the escapement. Thus, after each character has been printed, the pin-disc and type-wheel turn relatively to the dial-plate by an amount depending on the arrangement of the pins 60. Fig. 8 shows the pillar b and plate c in rear view. The driving-spring of the pin-disc is connected at one end to a sleeve extending from the ratchet-wheel 27, another ratchet-wheel co-operating with a detent-pawl on the plate 37 to prevent unwinding of the spring. As the plate c descends, the ratchet-wheel 27 engages with the dog 66, and is thus caused to rotate and wind the spring. If the spring becomes fully wound, the lever 67 turns on the pivot 68 against the control of the spring bolt 70, and the dog 66 descends with the ratchet-wheel. During the upward movement of the plate c, the ratchetwheel 29, (concealed in Fig. 8 by the wheel 27), is turned by the detaining action of the dog 75, so as to operate the escapement as described above. The dog 75 can be withdrawn from the path of the ratchet-wheel 29, when it is not desired to operate the pin-disc, the cipher employed being then of uniform or simple character. A pointer on the back of the dial-plate is made to register with any arbitrarily-selected character on the pin-disc before commencing to write, this character constituting a supplementary key to the cipher. In translating the message, it is placed between clips 93 on the scale-bar 94, Fig. 1, and the first character brought beneath the pointer 97. The known combination of rearwardly-projecting pins on the pin-disc is then set, and the disc turned until the pointer at the back of the dial-plate points to the known character which constitutes part of the key. The dial-plate is then adjusted successively to the letters of the code message, the translation of which is printed by the type-wheel. The inking-roller frame 98 is removable from the machine, or it may be turned aside by loosening the screw 108 to remove the type-wheel from the shaft.