Patent GB-319438-A (GB)
Title: Improvements in or relating to coding or cryptograph machines
IPC: B65D63/06
Filed: 1928-07-16
Abstract: 319,438. Marks, E. C. R., (International Code Machine Co.). July 16, 1928. Keyboards; type-lever actions. - In a coding or cryptographic machine independently mounted coding - wheels and ratchet wheels are actuated by pawl or finger means arranged so that one or more pawls actuate one or more coding-wheels and ratchet wheels while other pawls are held in an inoperative position until the actuated wheels are rotated into a predetermined position, whereupon one or more of the previously inoperative pawls engage corresponding coding-wheels and ratchet wheels and, upon actuation. rotate them one step forward. The invention is described in connection with a machine of the kind wherein the coding-wheels are provided on their opposite faces with electric contacts and, in rotating, produce current changes in electric circuits provided with indicating means such as electric lamps or typewriteroperating mechanism, one form of the latter being adapted to type simultaneously a ciphered message and the clear text thereof. The coding-wheels 75<a> - - 75<e>, Figs. 1 and 7, are in known manner, provided upon each of their opposite faces with twenty-six contacts, the contacts upon one side being connected in an arbitrary manner to different contacts on the other side, and the outer contacts of the two end wheels engage a corresponding number of spring-pressed contacts 22, 23 in stationary end-plates 20, 21. The contacts 22, 23 are connected by leads 28 to terminals upon contact boards 24<1>, 26<1> which are movable relatively to adjacent end-boards 24, 26 and carry plunger contacts 25<1>, 27<1> adapted to engage contacts 25, 27 on the boards 24, 26, there being twice as many contacts 25, 27 as there are contacts 25<1>, 27<1>, and the wiring being such that a reversal of the direction of the current for decoding is obtained by imparting a sliding movement to the members 24<1>, 26<1> by means of a connecting-link actuated by a lever 29. The coding-wheels 75<a> - - 75<e> are mounted upon a shaft 6, Fig. 1, within a casing, and provision is made for removing and reversing or interchanging them to increase the number of cipher alphabets available. The peripheries of the coding-wheels are provided with twenty-six recesses or pockets, 7, Fig. 1, respectively bearing the twenty-five letters a - - - and a number representing the position of the wheel in the set, the recesses serving also to receive the pawls or fingers which impart rotation to the wheels. Two ratchetwheels 5<a>, 5b are mounted at one end of the shaft and similar wheels 5<c>, 5d at the other end, each wheel being formed with twenty-six teeth and an adjacent flange 67 which has a single notch to correspond with the gap between two teeth; the flanges also bear alphabetical characters in alignment, with the gaps between the teeth. The ratchet wheels co-operate with pawls 11<b> - 11<d>, and 11<f> - 11<h> which control the engagement of pawls or fingers 72<a> - - 72<e> with their respective coding-wheels. The machine is provided with actuating-keys 4, Fig. 1, on key levers 2 which are pivoted on a spindle 3 and, on depression, actuate a universal bar 8 carried by levers 9 pivoted on the same spindle. The rear ends of the arms 9 are connected by a rod 10, Fig. 8, upon which are loosely pivoted the fingers 72a - - 72e formed with offset lower ends connected to springs 12<a> - 12<e> secured to adjusting- screws 61 mounted in a bar 62, whereby the upper ends of the fingers are urged into contact with the recesses 7 of the coding-wheels, restraining means being provided, however, to control such engagement. The finger 72<c> is in constant engagement with coding-wheel 75<c>, and pawl 11<h> likewise engages the ratchet wheel 5d, so that each time a key is depressed, these wheels are moved through one notch until, after twenty-six key depressions, that is one revolution of the coding-wheel 75<c> and ratchet wheel 5d, the finger 11<f> which bears upon the flange 67 of the ratchetwheel slips into the notch 5h of the flange and also engages one of the twenty-six teeth of the adjacent ratchet-wheel 5<c>. The finger 11<f> is secured on a sleeve 65<1> rotatably mounted on the rod 10 and carries a finger 11<e> which normally holds the finger 72e out of contact with coding- wheel 75e, these members thus being engaged after each complete revolution of coding-wheel 75<c> and ratchet-wheel 5d. Upon the next depression of a key the coding-wheel 75e and ratchet-wheel 5<c> are each turned through one notch, whereupon the finger 11<f> again rides on the flange 67 and disengages the finger 72e from its coding-wheel. In this way the coding-wheel 75<e> makes one revolution for every twenty-six revolutions of coding-wheel 75<c>. The finger 11<g> which bears on the flange 67 of the ratchet-wheel 5c is rigidly mounted on a rotatable rod 65 carrying an arm 68 which normally holds finger 11c out of contact with ratchet-wheel 5<a>. Finger 11<c> is secured to a sleeve 64 rotatably mounted on rod 10 and provided with an offset arm 11<a> which holds finger 72<a> out of contact with coding-wheel 75<a>. Consequently at the end of each complete revolution of ratchet-wheel 5<c> the finger 11<g> enters the notch 5g in the flange of that wheel, thereby moving the arm 68 to allow finger 11<c> to engage ratchet-wheel 5<a>, and thus causing arm 11<a> to release finger 72<a>, so that at the next depression of a key the coding-wheel 75<a> is moved through one notch..Similarly, the fingers 11<d>, 11<b> control detents 76, 74 governing the intermittent rotation of coding-wheels 75<b>, 75<d>. The key levers 2 when depressed enter knife-switch contacts 31, Fig. 7, connected by leads 32 to the corresponding contacts on the board 26 by leads 33 to the corresponding duplicate contacts on the board 24. Leads 34 connect the direct contacts 25 to lamps 35 which are set behind lettered glass panels 37 in the front of the machine, the lamps being also connected to the " reverse " contacts 27 by leads 38 which are tapped into leads 34. A three-way switch 44 may be connected in the electrical circuit to enable the coded message to be printed by an auxiliary typewriter instead of reading it from the illuminated letters, the keys of the typewriter being operated by solenoids 47 connected to the switch by leads 46; or a dual machine provided with two sets of solenoids 52, 54 controlling type-levers may be connected by leads 51, 53, 55 to enable the message to be typed simultaneously in clear text and code. An index line 60 is provided across the end plates 20, 21 and stationary discs 18 to facilitate the initial setting of the coding and ratchet-wheels.