Patent GB-191305390-A (GB)
Title: Improvements in Machines for Enciphering and Deciphering Messages.
Inventor: FULLER ERWIN WILLIAM
IPC: G09C3/00
Filed: 1913-03-04
Granted: 1914-03-04
Abstract: 5390. Fuller, E. W. March 8, 1912, [Convention date]. Machines for secret writing ; keyboard operators; relay actions.-In a keyboard machine for coding and decoding of the kind in which the code is changed automatically at each stroke of the keys, the character - selecting mechanism comprises a graded series of mutilated pinions adapted to operate a series of key-controlled pinions. The characterselecting mechanism may be adapted to display or to print characters, and in the machine shown the character - selecting mechanism operates links 54, which are provided with character-targets 56 and are connected to the key - levers 55 of an ordinary typewriter. The key-levers 24 of the machine are provided with keys 24<a> and are associated with a series of pinions 25 splined on a shaft 33 and adapted to engage a series of mutilated pinions 35 secured to a shaft 36. The shaft 33 is geared to a shaft 39 provided with a helical series of fingers 38, the gearing comprising a reversing-clutch 43, which is set by keys F, B and is adapted to connect shafts by means of two gear-wheels 41, 48 or by means of three gear-wheels 40, 49, 50. The shaft 39 is also connected by bevel-gearing 93, 98 to a setting- knob 90 and an indicating-dial 94. The keys 24<a> are arranged like a typewriter keyboard and are thirty-eight in number, there being the same number of pinions 25, fingers 38, and pinions 35, and the pinions 35 having from one to thirty-eight teeth graded from left to right. The pinions 25 are engaged by forked shift-levers 33, which are held by springs 30<a> against dogs 28 connected to the key-levers 24 The forked levers are pivoted between plates 29, and to save space the dogs are nested, and alternate dogs are pivoted to opposite plates. The springs 30<a> are each secured to one of the forked levers and to one of the dogs further up the series. A reciprocating notched bar 30<b> operated by a cam 30<d> is provided for returning the forked levers. The links 54 are connected to levers 27 pivoted at 27<x> on levers 52, which are pivoted on a shaft 53 and are held by springs 57 against a cam shaft 59, springs 58 also being provided to hold the levers 27 against a stop-bar 59<a>. The levers 27 are formed with fingers 27<a> adapted to engage the fingers 38, the arrangement being such that, when any finger 38 is vertical, it engages the finger 27<a> of the associated lever 27. During the rotation of the shaft 59 all the levers 27, except the one which is held up by the corresponding finger 38, pivot ineffectively about the bar 59<a>, but the selected lever 27 fulcrums on the finger 38 and depresses the associated key-lever 55. The machine is driven by means of a shaft 62, which may be driven by a hand-crank but is preferably driven continuously by a motor. This shaft carries a loose pinion 63, which is geared to the shafts 36, 59 and is provided with a one-revolution clutch consisting of a pawl 82, which is pivoted on the pinion 63 and is adapted to engage a ratchet-wheel 84 fast on the shaft. The key-levers 24 rock a universal bar 72 secured to a shaft 74, which is connected by a link 78 to a pivoted detent 81, which normally holds the pawl 82 clear of the ratchet-wheel. On depression of any of keys 24@, the detent releases the pawl 82, and the shaft 63 makes one revolution, the clutch being then released by means of a cam 87 on the shaft 59, which engages a tail 88 on the link 78. In coding a message, the corresponding keys 24<a> are operated in sequence, the effect of each key-operation being to release the associated forked lever 30 and to shift the associated pinion 25 into gear with the corresponding mutilated pinion 35, so that during the rotation of the shaft 63, the shaft 39 is rotated through an angle corresponding to the number of teeth on the selected pinion 35. Each key 24<a> is thus effective to rotate the shaft 39 through a particular angle, but the finger 38 which is brought to the vertical position and the selected character are dependent on the antecedent setting of the shaft 39, and in this manner the code is changed at each operation of the keys. The code is complicated by turning the shaft 39 at intervals by means of the knob 90 and by operating the keys F, B to cause the shafts 33, 39 to be driven in the same or in opposite directions. The dial 94 for indicating the setting of the shaft 39 is provided with characters which are read with reference to series of marks a, b and are arranged in the same order as the characters corresponding to the key-levers 24. In decoding a message, the keys F, B and the dial 94 are first set to the adjustment that existed during the writing of the part of the message that is being decoded. The keys 24<a> are then operated in sequence, and after each key-operation the dial 94 and consequently the shaft 39 are set by the knob 90 to bring the same character on the dial as the one on the operated key opposite the particular mark in the series a or b that is being used. To complicate the code further, there may be provided a second dial 99 which bears numerals or characters, and is independently adjustable with reference to the dial 94, preferably by connecting the dial 99 to the gear 93 and disconnecting the dial 94 from the gear 98. Key interlocks. - When any key-lever 24 is depressed, the remaining key-levers are locked by means of pivoted dogs 75, which are tensioned by springs 77 and are adapted to engage notches 78 in the key-levers. The dogs are normally held back by the universal bars 72 referred to above.