Ciphering machine

Application filed February 6, 1823, Serial No

It lias already been proposed to use for ciphering of a clear text arid for deciphering machines which either type the ciphered letters in a similar manner to that, of a type5 writing machine or which produce a-ciphered - perforated cable tape or operate an indicating device. The operation of · machines of this type is based for instance on the interchanging of the closed circuits between 10 the keys marked with the letters of the alphabet and the type levers or the levers of a perforator for cable tapes each time after the sending of one or more of a determined number of letters. As soon as with two 15 machines of this type this interchange, which is per se irregular, is effected in exactly the same manner, a telegram which, has been ciphered with the aid of one machine can be deciphered with the aid of a corresponding 20 machine. A condition is however that the number of letters counted from the same; starting position has remained the same. At the sending of telegrams, especially with wireless telegraphy, one must however coupt 25 upon the accidental omission of certain letters or groups of letters. The machine which is used in such a case for deciphering' is thus unsynchronized, so that not only the letters which have been omitted but also all 30 the succeeding text cannot be deciphered any more.

According to the invention this defect is avoided or at least restricted greatly by providing on the ciphering machine a device 35 by means of which finishing of a series of letters of determined length is signalized every time to the operator of the machine so that he can mark the beginning of/the new series of letters in the ^ciphered text. It is 40 thus possible to compare and if necessary to correct the position of the deciphering machine after every series of letters. The termination of the series of letters is preferably signalized by the sounding of a bell 45 or by the lighting up of an incandescent lamp. It would be better still if, after the termination of a determined series of letters, the machine is automatically stopped entirely or partly or thrown out of operation 50 so that it is impossible to continue the typing; The mechanism which effects the interchange of the letters may for instance be stopped. The beginning of the new row of letters may then be indicated for instance by . 617,352, and in Germany February 11, 1922.

repeated sending of the same letter. The 55 device which serves for counting the length of the row of letters may continue to operate, if this should be desirable for any reason, if the same letter is· repeated each time for a. determined number of times,. Tt would be 60 still better to reverse the machine in such a manner that it types clear text, the mechanism which effects the interchange of letters being stopped,. wherefrom results the advantage that in the clear text an easily recog- 65 . nizable message can be given and that after the sending of this message the ciphering can be continued with the machine, which during this sending has not been adjusted for sending code. Such a message can con- 70 sist for instance of a check member, or if desired the number of letters which have been sent up to this ihoment. For each series of letters a new key indication might be selected on the machine, which key indica- 75 tion for safety’s sake would be sent in the clear text several times. Service regulations might further be inserted. Clear' text might further be signalized by special signs, for instance by spaced type. 80

In order to make the invention clearly understood I shall proceed to describe the same with reference to the accompanying drawing wherein:

Fig. 1 shows by way of example a- cipher- ₈s ing machine according to this invention.

Figure 2 is an edge elevation of one of the rotatable contact drums showing the irregular connection of the contact points.

Figure 3 is a front elevation of the drum, go Each key of the key board 1 of the typewriting machine connects by means of a contact operated at the depression of the key the lead 2 with one of the. leads contained in cable 3 belonging to this key. 95 The several leads corresponding with the keys are insulated from one another and united to form a cable 3 which is in contact with a drum 4. Upon the end faces of this drum as many contacts are arranged in a 10c circle as the typewriting machine has keys and the several leads of the cables 3 are connected with these Contacts in such a manner that every two opposite contacts are connected with the same lead. The. drum 105 4 is mounted on a shaft 5 so that it may be displaced in longitudinal direction but cannot revolve with said shaft. Upon the

1,657,411 same shaft four revoluble drums 6, 7, 8 and 9 are arranged which carry on both end faces the'same number of contacts as drum 4. In these drums 6—9 the opposite con5 tacts are not connected with one another but the contacts of the opposite rows of contacts are arbitrarily interconnected in confused order but in such a way that only one of the contacts of the one side is con10 nected with one of the contacts of the other side. Upon the ends of shaft 5-two drums 10 and 11 are keyed which have coptact pins . only on tbe end face which is turned towards the other drums. These contact pins of each 15 drum 10 and 11 are connected by cable, 13 and 14 respectively, with a drive for a type lever of a perforator 12. The conductors 13 and 14 are cables which contain as many avires as there are contact points on the in20 dividual contact drums, for example, twentysix. The type levers of the telegraphic perforator may for instance be operated each by one electromagnet. The other terminals of the several drives for the telegraphic 25 perforator are connected with the minus pole of a source of current. The drums 6—9 are coupled with the driving wheel 15 by toothed wheel gear of a variable transmission in that each of the drums 6, 7, 8 ²⁰ and 9 are driven by gears having a different number of teeth, as shown at 16 and 17. For clearness sake only the couplings for the drums 6 and 8 are shown on the drawing. The toothed wheels 16. and 21 on the one 3> hand and .17 and 22 on the other hand are keyed on shafts 19 and 20. The toothed wheels 16 and 17 are in gear with the spur wheel 18 rigidly connected with the driving wheel 15, the toothed wheels 21 and 22 be40 ing in gear with toothed crowns of the drums 6 and 8 respectively. The drums 6, 7, 8, 9 have marks, for example letters, on their periphery, which serve for the adjustment of the drums to a certain key word at 45 the beginning of coding. For this adjustment it is possible to disconnect the drive gears for the drums, adjust the drums to the key word and again connect in the drive gears, so that, for. example, as in the exam50 pie shown, the key word “niag” appears before a window (not shown). The driving wheel 15 has tenth 23 on its circumference with which the blade-spring 24 of a resiliently mounted armature 25 engages. Op55 posite the armature an electromagnet 26 is arranged, the exciter coils of which are connected by one of their terminals with the lead 2. The drum 4 is pressed by spring 28, through the intermediary of lever 27, 60 against the drum 6 but it may be brought in contact with the stationary drum 10 against the action, of spring 28 by the depression of the lever 27. The drives of the type levers of the telegraphic perforator are 65 connected with the contact pins of drum 10 in such a manner that, at the contact between the pins of the drums 4 and 10, any desired letter of the telegraphic perforator is operated by the same letter of the key board 1. On lever 27 an insulated electric- 70 current-conducting-plate 29 of sheet metal, connected with the phis pole of tlie source of current, is fixed. This piece of sheet metal 29 has at its front end two contact plates 30 and 31 opposite which two spring con- 75 trolled contacts 32 and 33 are arranged. The contact 32 is connected with the lead 2 and the contact 33 is connected with the terminal of the electromagnet 26. The contact 33 is supported by a lever 35 which is piv- 80 otally mounted on a stud 34 so that it oscillates only with difficulty and is held by friction in any position to which it is brought. On this lever 35 a blade spring 36 is fixed so that it is not in contact with the 85 armature 25 if the lever 35 is in the position of rest shown on the drawing. Opposite spring 36 the armature 25 has a groove 37 and behind this groove a nose 38. 39 is a counting mechanism of commonly used »0 construction the electricity-conducting figure disks of which are connected by way of the axle and the casing of the counting mechanism with the lead between the contact 33 and the magnet 26. Upon the circumfer- 05 ence of the figure disks the contacts 40—44 slide, said contacts being adapted to be singly connected with the plus pole of the source of current by means of the switches 45—49. The figure disks with sliding con- ¹⁰⁰tacts have on their circumferences plates of insulating material (those visible on the drawing are designated 50, 51, 52) which are of such size and which are arranged in such a manner that they interrupt the conducting 105 connection between the sliding contacts 40— 44 and the figure disks only if said figure disks are in the zero position. The feeding of the counter is effected by the driving wheel 15 in such a way that at each partial HO rotation of wheel 15 the unit disk of the counter is advanced by one figure. The ratio of the number of teeth of the driving wheel 15 to those of the numbering device meshing therewith is selected so that each H5 time the member 24 moves the wheel 15 forwardly by one notch 23, the numbering or counting mechanism is adjusted further for one unit.

The ciphering machine works as fol- 120 lows:—

By the depression of a key of key board 1 one of the electromagnets of the perforator 12 is excited which is) determined by the position of the drums 6, 7, 8 and 9 so that the 125 corresponding letter is perforated. At the same time the magnet 26 situated in the circuit 2 common to all letters is excited and the armature 25 is attracted. When the key is released the circuit is interrupted and the 130

1,657,411 armature is released by the magnet, so that the contacts 31 and 32 is interrupted and a it returns to its initial position and makes the driving wheel 15 rotate by one tooth.

With the driving wheel 15 the spur wheel 5 18 rotates and makes the rotatable drums 6—9 rotate by different amplitudes owing to the toothed wheel transmission of different radii. All the connections of the key board 1 with the telegraphic perforator 12 are 10 thus changed so that, at the next depression of the same key of key board 1, another letter as before would be perforated by the perforator. .

The device which, according to the in15 vention indicates the termination of a series of letters, in the present case by stopping the machine, is controlled by the counting mechanism 39. In the form of construction shown by way of example the machine 20 is stopped always after the indicating of one thousand letters. With this object m view the sliding contacts 40, 41 and 42 are connected across the switches 45, 46, 47 with the net-work so that the current may 25 flow from the plus pole of the net-work over the figure disks for the. units, tens and hundreds. Only if all three, disks are at the zero position the current is interrupted through the insulating plates 50, 51 and 52 30 and the machine is stopped. By corresponding insertion of the switches 45—49 the length of the row of ciphered letters can be altered as u....-.— counting mechanism shows the number -uy B^nmission ’of sums*will 100

13999. If a key of the key board 1 is now five letters each, the omission 01 si_em> depressed, so that the 14000th letter is· ciphered, all number disks which have previously indicated “9” will indicate “0” as soon as the armature 25 returns to its position of rest. The plus pole of the source of current is thus cut off from the· machine whereby further typing is prevented. By depression · of lever 27 the contacts 31 and 32 can be brought in contact -whereby the 45 plus pole of- the source of current is directly connected with the lead 2 while avoiding the switching magnet 26 and the counting mechanism 39. At the same time the drum 4 is pressed against the stationary, drum 10 so that clear text can be typed with the machine as long as lever 27 remains depressed. The feed mechanism for the ciphering, the driving wheel 15 and the counting mechanism 39 remain out of operation «luring this time. If ciphering has to be tvped again it is merely necessary to release tlie lever 27 so that it is returned into the initial position by the action of spring 28 At the depression of lever 27 lever 3o with contact 33 had been lowered at the same time. The blade spring 36 is thus brought in contact with the end face ot the armature 25 along which it slides downward. As soon as lever 27 is returning to its initial position the connection between connection between the · contacts 30 and 33 is produced since lever 35 remains in its lowered position, being held by friction m the bearing indicated by stud 34, and thus ,o keeping the contact between spring 36 and armature 38. so that now only the counting mechanism 39 is switched out of the circuit 2 common to all keys. If now a key of the key board 1 is depressed and the first letter 75 of the new row of ciphered letters is thus being typed the feeding mechanism executes a feeding movement so that the counter registers again the letter which has been transmitted, the counter indicating the number so 14001. The connection over contact 40 and lhe unit disk is thus re-established. At the same time the connection of the contacts 30 and 33 is interrupted in the following manner. When the armature approaches the S5 magnet 26 the front face of the armature releases the blade spring 36 so that this blade spring can come in contact with nose 38. At the return of the armature 25 to the position of rest the blade spring 36 en- go gages with groove 37 in which it moves upward through the intermediary of the armature. The lever 35 returns thus to the initial position. At the next- descent of the armature the blade spring 36 which is still 05 in engagement with groove 37 is released.

me row 01 — and assumes again the position of res

Tn the drawings the shown on the drawing.

desired, in tne drawing . _{cipher W}ntten in groups of < ° 1 __cirrna Will 1 Ωί) live WLUCl© cavuj Viiv ---------. C -,11 be more easily detected by comparison with the original than would be the case where grouping of signs is not employed.

The perforated strip is inserted in a telegraph machine of known construction 105 and on passage therethrough produces the Morse code in the telegraph line. When the electric current is passed im opposite direction through the drums 6, 7, 8, 19, the machine may be used for de-codmg. The 110 operator can accurately supervise on the perforated strips of the perforator, the perforation marks and their groupings. The connection between the perforator and the drums of the sending apparatus is effected 115 by the cables 13 and 14, of which each branch leads to the magnets of each perforating key of a known type of magnetic perforating machine, for example the Wheatstone type.

The device described 'is a coding appaiatus. If a message received in code is to be deciphered, use is made either of a special device, composed of the same parts as tlle, machine described, but in which the lead bundles 3 and 14 are interchanged, or of an apparatus according to Figure 1 provided with a suitable multiple electric switch by means of which each individual conductor from the bundle 3 may be interchanged with

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1,667,411 the corresponding conductor of the bundle 14. For de-coding, it is only necessary to pass the electric current through the ciphering rolls in the direction opposite to that for β ciphering.