US2232575A - Means for forming cryptographic messages - Google Patents

Description

Feb. 18, 1941. J. B. WALKER ETAL.

MEANS FOR FORMING CRYPTOGRAPHIC MESSAGES Filed June 2l, 1938 4 Sheets-Shea?I l Feb. 18, 1941. .1. B. WALKER Erm.

MEANS FOR .FORMING CRYPTOGRAPHIC MESSAGES Filed June 21, 1938 4 Sheets-Sheet 2 :furl-1 Feb. 18, 1941. .1. B. WALKER Erm.

MEANS FOR FORMING CRYPTOGRAPHIC MESSAGES Filed June 21, 1938 4 Sheets-Sheel 3 EN @NJ @Nmww Fel). 18, 1941. 1 B, WALKER TAL 2,232,575

MEANS FOR FORMING CRYPTOGRAPHIC MESSAGES Filed June 21, 1938 4 Sheets-Sheet 4 Il f5 Patented Feb. 18, 1941 A UNITED STATES PATENT OFFICE MESS AGES

Joseph B. Walker and Sheldon K. Johnson, Los Angeles, Calif.

Application June 21, 1938, Serial No. 215,048

19 Claims.

This invention relates to a method of and highly eilicient mechanism for setting up and decoding cryptographic messages in such manner and .by such means that the control key used is 5 factually a wholly random one throughout endless permuations. The net result is that there is never a repetition of the pattern in any two messages and consequently itis definitely impossible for even the most expert and painstaking cryptographers to break a message so created.

It has heretofore been proposed to utilize as a key or control unit in cryptograph machines an endless web or tape, such as a strip of motion picture iilm material, for example, said web being l divided into spaces or frames and each frame in turn being provided with a group of elements, such as perforations for example, the spacing of the perforations within the respective frames, and their sequence, determining the effect which that l particular frame will exert in setting up a rnessage impulse. Such a control unit is disclosed in Patent No. 2,151,453, issued to one of us on March 21, 1939.

In the present invention, we utilize a multi- 9" plicity of plate or card-like members or units and divide the surface area of said units into a multiplicity of frames having groups of perforations in the several frames. The disposition of the perforatlons of the groups within the frames 30 and the sequence of the several groupings determines the effect to be exerted by a given frame in setting up a message impulse.

Note that in Patent 2,151,453, a frame is that portion of the endless tape which carries those perforations which control a single message impulse upon operation of a scanner. The present application differs in placing the "frames" upon shuiiieable cards instead of upon a tape, and in this application the term frame refers lo to that area of such a card containing the necessary number of control elements (perforations 1 in Fig. 7 for example) to determine the character of a. single message impulse when the scanner hereinafter described is operated. In other 7 words, a frame is one of the divisions 6 in Fig.

'7, or one of the spaces representing one of the divisions of one of the columns shown in Fig. '1.

An important functional difference in the two cases is that with the tape, the entire numbers il of frames are fixed in non-changeable sequence relation to each other, with the result that when the tape has been once used throughout its length there would be a repetition of the sequence pattern in again using it, Whereas with the inde- H" pendent cards or plates, capable of being shuflied with respect to each other, it is possible to continuously shift these frame carrier sequences into new relations to each other.

Also, we scan one frame of a plate, then another frame of the next plate, and so on 5 through a stack of said plates instead of first scanning all the frames of a plate; with iinportant functional results, as hereinafter described. Having exhausted a stack of plates, they are then susceptible of rearrangement in a new random sequence, the permutations of which randomness are of a very high numerical order.

In the accompanying drawings:

Figure 1 is a fragmentary perspective view of a plate or card shifting mechanism hereinafter described, with the scanner and associated parts omitted to preserve the clearness of the drawing;

Fig. 2 is a fragmentary rear view of the structure shown in Fig. 1;

Fig. 3 is a sectional view of a selector here- 20 inafter described;

Fig. 3B is a sectional view on line Sii-3 of Fig. 3;

Fig. 4 is a detail view of the scanner showing two only of the scanner units thereon;

Fig. 5 is a horizontal sectional view online 5-5 of Fig. 4;

Fig. 6 is a vertical sectional view illustrating one of the contact elements of a scanner unit;

Fig. 7 is a fragmentary view of one of the 30 plate-like key or control elements hereinafter described;

Fig. 8 is a vertical sectional view through one of the box like receptacles into which a plate is thrust after it has been scanned; y

Fig. 9 is a horizontal sectional view on line 9-9 of Fig. 8;

Fig. 10 is a view partly in side elevation of a character forming mechanism hereinafter described; 40

Fig. 11 is a plan view of the selector of Fig. 3 with some of its parts omitted;

Fig. 12 is an enlarged sectional view 0f a part of the character forming mechanism;

Fig. 13 is a diagrammatic View of the wiring; 45

Fig. 14 is a detailed view of a one-way pawl hereinafter described, and

Fig. 15 is a fragmentary sectional view through a portion of the groove of a cam disk hereinafter described and illustrating the cam portion of the base of said groove. f

Like numerals designate corresponding parts throughout the several gures of the drawings.

Referring to the drawings, 5 designates a platelike element which is preferably of sheet metal,

such as Duralumin. I'his metal is non-corrosive, strong, of light weight, and may be used in plates so thin that a great many of them may be stacked in a small space. Each plate comprises one or more frame spaces 6. Preferably each plate' is divided into quite a large number of such frame spaces, and each frame space in turn is provided with one or more perforations 1.

The disposition'of these perforations within the frames, i. e., the spacing or grouping of the perforations with respectto each other within the frames, and the sequence of the groupings upon the plates and through the stack of plates determines the effect to be produced. In the particular embodiment of the invention which we have chosen to illustrate for purposes of explanation,4

we use from one to flve perforations to a frame, but the number will be varied in accordance with the type of cryptographic machine in which the plates are employed.

The plates are disposed in a stack in a frame which may be constituted by the angle strips 8. There are two of these frames disposed side by side one carrying the stack of plates, A, being scanned and the other receiving the plates, B, which have already been scanned (Fig. 1) and have been thrust laterally from scanning position over intothe other frame, there to be rescanned in a later operation.

Mounted to travel alongside the frames are scanning and plate pushing elements, only one of which is shown, since they are duplicates. Each of these mechanisms is mounted to travel along shafts III and II, the former being a splined shaft and the latter being a worm or screw threaded shaft. Spring motors I2 and I3 tend to rotate these shafts and said shafts are held against rotation by escapement pins I4 and I5. Electromagnets I6, |65 are adapted to withdraw detents I1 and I8 from the path of said pins at the proper time to permit the shafts to rotate.

A gear wheel I9 splined on shaft I0 and consequently operable by said shaft at all points in its bodily travel along said shaft meshes with a gear 20 upon a shaft ZI. This shaft carries a cam disc 22 having a groove 23b formed therein. This groove is Aconcentric with shaft 2| but its bottom has a short depression 23k with a quick rise to a level, the function of which is to act against the inturned end 23a of a. rock shaft 23 to impart a partial turning movement to said shaft in vits bearings 24.

The turning movement of the shaft 23 is translated through worm gears 25 into partial turning movement of vertical shafts 26 and 21. The vertical shafts 26 (see Figures 2, 4, and 5), carry ngers 28 which engage in loops 29 of a bar 30 constituting a part of a scanner. Bar l3|! is mounted in a scanner body 3I the ends of which engage vertical threaded rods 32, the function of which rods is to adjust the scanner vertically under the influence of cross bar 33 and gearingA This gearing may be manually actuated if desired, though we prefer to actuate it by a suitable trip mechanism after the scanner has completed its scanning operations in one horizontal row of plates. The bar 30 is movable toward and from the perforated wall 32a of a box-like member 338 which constitutes a part of and moves longitudinally with the pusher mechanism. A pusher 34 is mounted to move in guides 35 and is connected by a connecting rod 36 with the wrist pin 31 of disc 22. Thus upon each release of the escape- (See Fig. 5.)

ment I disc 22 makes one quick revolution. The initial movement of the disc acts through rock shaft 23 to retract, bar 30; i. e., vto move said bar away from the face of box 33a.

'I'he scanner carries a plurality of scanner units said units corresponding in number to the columns of perforations upon the plates and each scanner unit in turn comprising a group of pins 38 (five to a group are shown), the pins of the units scanning or seeking to enter the perporations 1 in a single frame of a plate through the perforations 32a of the rear wall of the box. 'I'he pins 38 carry collars which are engaged by bar 30 to move the pins outwardly. This frees the pins from the previously scanned plate 5, i. e.the end plate of the stack and permits the pusher 34 to thrust said plate from stack A to stack B.. p

After making a single revolution disc 22 comes to rest with the pusher in retracted position, and escapement I4--I8 acts to permit the shaft II to make a partial turn to feed the pusher mechanism bodily along the frames and into position to engage the next plate of the stack. During this movement the end plate 5, which has been scanned, is forced past ball detents 39, set in the wall of the box 33.

The open side of box 33 faces in one direction and the open side of its companion box 33c faces in the opposite direction and when a plate is thrust from 33a into 33, pusher pins 42, actuated by cams 43 upon the vertical shafts 21, (Figs. 2, 8, and 9) act to thrust said plate toward the open side of the box 33c and past spring actuated ball detents 39, to thereby make room for the next plate which will be thrust into said box.

To facilitate the movement of the plates into and out of the boxes anti-friction rollers 44 are mounted upon the bottoms of said boxes. Tapes 45, the ends of which are engaged with spring actuated rollers 45a acting after the manner of shade rollers, have their ends connected to -the side walls of the boxes, the ends of the tapes being separated as indicated at X (Fig. l) to Aleave an open -space through which the plates may pass in their passage, from box 33*al to 33. The function of the tapes is to provide an inner supporting wall for each of the stacks A, B ofthe plates. That is to say, those portions of the tapes which extend from 33 toward the rollers 45*l support the inner side edges of plates B. while those portions of the tapes which extend rearwardly from the point a: support the inner side edges of the plates A. While the tapes are attached to 33a and 33c as above stated, a gap is leftin the tapes at at, Fig. 1, so that the tapes will not prevent the plates from being thrust from box 33a to box 33. Of course the rear portion of the lower tape does not show in Fig. 1 because it is hidden by plates A.

Referring now to Figs. 4 and 6, it' will be seen that each pin 38 functions at times to complete an electric circuit. To this end, each pin has a spring leaf 48 of an electric circuit making and breaking element bearing thereon, the other contact leaf being shown at 41. If, when block 30 moves forward to scanning position any given tracted so that no current can now from the completion of the contacts 46 and 41, except during the forward movement of the scanner in its scanning operation.

The circuits completed by the several contacts 'are effective as hereinafter described to energize one or more of the solenoid magnets 50. These magnets equal in number the pins of a scanning unit, to wit: iive, and each scanning group of five contacts bears the same relation to these magnets that every other scanning unit does.

These magnets serve as the actuating members of a selector of the character of that shown in the above named Patent No. 2,151,453. 'I'hat selector is shown in Fig. 3 of the present application. Here the magnets function to shift notched bars l longitudinally and the transverse alignment of the notches 5i* of the several bars determines which o1' the transverse bars 52, lying above bars 5I, may drop to a lower position. Bars 62 carry upturned vertical extensions 53 (Figs. 3 and 11) which function as stops in conjunction with the operation of a character forming mechanism to be presently described.

This character forming or printing mechanism functions under the manipulation of a manually operable key to move a printing mechanism a distance determined by the nature of the key manipulated and then further functions under the inuence of the perforations of the plates through the stops 58 to add to the movement of the printing mechanism so that if key M of a bank of keys be actuated the rst movement of the printing mechanism will be to the M position and if the perforations scanned by the particular scanning unit then operative sets a stop 53 through the selector to add ve letters, thenthe printingmechanism is stepped forward ilve more letters, positionally on the circumference of a wheel 55 or from M to R.

Upon reversal of the operation, the manipulation of R key moves the printing mechanism to R printing position and then the same scanning operation brings about the setting of a stop to permit, through suitable reverse mechanism, a reverse movement of the printing mechanism to subtract the previously added five letters and We get back to the M printing position. After each operation of printing a letter, the parts return to zero position. The results above described are achieved as follows:

Referring to Figs. and 12, 55 designates a printing wheel having type characters 56 upon its periphery. This wheel is carried by a shaft 51 which has affixed to its lower end a gear 58 (Fig. 12) which constitutes one member of a conventional type diierential. The companion gear of the differential indicated at 59 is fast upon the upper end of a stub shaft 60 said stub shaft being journaled to turn in a bearing 6I and upon a thrust bearing GIB. Floating gears 62 and 63 are mounted upon shafts that are carried by a ring 64, said ring being rotatively mounted in a block 65 supported upon an anti-friction bearing 66. The upper corner of block 65 is provided with gear teeth 61a and a bevel pinion 61 meshes with these teeth.

A spring motor 68 tends to turn block 65 forwardly (or in the direction of arrow Z at all times. A spring motor 69 tends to turn shaft 51 forwardly, through bevel gears 10. Shaft 51 is free to turn in block 65 except when locked thereto as hereinafter described. The lower edge 0i ring 44 is provided with notches 64a which equal in number the characters upon wheel Il.

As is illustrated in Fig. 11 brought together to form a ring just outside the block 65, only one of these stops being shown in Fig. 12. As long as the selector bars 52 are in elevated position. the beveled portions 53e of the st'ops hold the outer ends of lock 1evers'1l in.

elevated position against the action of spring 12. Only one lock lever is shown in Fig. 12. The locklever is pivoted at 13 and when its outer end is raised, its inner portion is depressed. The inner end of levers 1| enter slots '14 formed in stub shaft 60, there being as many levers 1I as there are stops 63. When a given stop 53 drops with its selector bar its lock lever 1I is released. In addition, theportions 53, of the stop are lowered into the path of movement of a stop pin 16 carried by block 65.

In the code forming process, the movement of the lock lever 1I is such, under action of spring 12, that lt locks 60, 64 and 65 together so that shaft 51 is in effect locked to block 65. This is accomplished by having lock lever 1I move upwardly into engagement with a notch or tooth 64a of ring 64 while the end of the lever is engaged as described in the slot of shaft 60. In the decoding operation, ring 64 is locked against turning with block 65 by a reverse lever 11 pivoted at 18 to bearing 6I and having a locking pin 19 pivoted thereto.

A spring detent 89 engages lever 11 to hold pin 19 in an elevated position where it engages a tooth 64'i of ring 64 and thus holds the ring against turning. At the same time a ring 8| is manually turned down to cover the upper portions of slots 14 and prevents upward movement of the inner portion of said lever to locking engagement with teeth 64'. Thus, when handle 11 is moved upwardly and ring 8l is moved downwardly, the ring 64 is disengaged from block 65, because lever 1i moves out of engagement with its notch 64a of said ring. However, at the same time, ring 64 is held against turning by pin 19 and thus permits the differential to function in the reversing or decoding operation as hereinafter described.

A bank of keys, similar to typewriter keys, bearing the letters of the alphabet and only one of which is shown at and designated 82 in Fig. 10, initiates the release of the mechanism. When such a key, for example the M key, is depressed, it acts through rock lever 83, link 84, and rock lever 85 to draw stop slides 86 and 86a downwardly so that a notch 81 of slide 86 registers with the path of movement of stop pin 88 upon disc 55. This disc thereupon rotates in the direction of arrow Z, under action of spring motor 69, until a pin 89 strikes stop lever 90. This lever was swung to such intercepting position when the key was depressed by a cam 9|, which thrust a slide 9i to the left. (Fig. 12.) This slide has pivotal engagement at 92 with lever 90. Lever 90 is in turn pivoted at 93.

In its movement to vertical position, a spring lip 94 on the lower end of the lever snaps past a notched upstanding circular rib 958 on the ring-like member 95. Therefore the lever 90 is held in vertical or arresting position. The ringlike member 95 is carried by radial spokes 95k which project from a collar 95b surrounding but unattached to shaft 51. A spring 95c normally holds the ring in such position that a tooth lies opposite each spring lip on the lower ends of the stops 53 are levers 90 so that these lips must snap over a tooth in moving to vertical position. But when any stop 53 drops, a cam 53a thereon (see Figs. 12 and 14) acts upon one of the radial pins 95f to turn the ring slightly against the action of spring 95c but enough to move the tooth from in front of the spring lip and bring a notch opposite said lip, through which the lip may pass.

One end of spring 95c is attached to a fixed member 95x and the other is attached to the ring to hold a pin 95y of the ring against 95x until the ring is shifted slightly circumferentially as described by the action of one of the cams 53a whereupon a spring 91 retracts the slide 9| and moves lever 90 to an inclined and non-intercepting position. 'I'he c'am 53' (Figs. 12 and 14) does not affect the slide when the key 82 returns to elevated position because said cam is pivoted upon the key shank at 98 to swing downwardly but is stopped against upward swinging movement by a pin 99. The movement of the slide 9|a closes electrical contacts |00 through a lip |0| for a. purpose presently to be set forth. The structure just described is duplicated for every key, or, in other words, for every letter of the alphabet.

When by the depression of M key, the disc 55 is initially set in operation, it comes to a stop with its printing character M opposite a hammer |02 similar to the hammer of the conventional Hammond typewriter. However, the hammer does not act at this time. The closing of the circuit at |00 completed the circuit from the scanner pins to the solenoid magnets and thus under the influence of the plates 5 and the scanner, one of the stops 53 is dropped. 'I'he dropping of this stop accomplishes two things.

First, it permits lock lever 1| to move into position to lock 60, 611 and 65 together. Prior to that time and during the first turning movement of disc 55 gear 58 turned with the shaft 51 but since ring 64 was free of the lock lever, said ring traveled around without affecting anything. But as soon as 641, 65, and are locked together, they turn as a unit under the action of spring motor 68 whenever block 65 is released and said block is released by the continued downward movement of stop plate 86a under the action of the key 82 because this further movement of said stop plate brings a notch of said plate into alignment with a stop pin 16 on block 65 and permits to rotate until pin 16 abuts the stop projection 53e on the dropped stop lever 53.

If, for example, the stop lever dropped under the action of the scanner provides for a further ve step movement of block 65 then the disc 55 will be moved a distance equal to five more letters or from M to R. The printing character R then lies in front of the hammer and when said hammer is actuated it forces a paper strip and inked ribbon P forcibly toward the R character on disc 55 and prints said R character upon the paper strip. 'I'hus the action of pressing key M, has, under the influence of the random sequence plates 5 resulted in printing a character R.

We are aware of the fact that numerous machines have been devised for effecting substitutions of letters, one for another, but as far as we know, we are the first to effect such substitution under the influence of a substantially inexhaustible random sequence key. After each operation, the stop levers are returned to elevated position by the action of a clearing lever 33x (Fig. 3) which corresponds to the like member 33 of the aforesaid pending application Serial Number 120,457. However, this restoration may be manually effected and we have indicated a handle 33j for throwing lever 33X upwardly to clear the bars 53.

Thereupon, stop 53 is lifted to free pin 16 and block 65 completes a rotation to the point Where pin 16 again comes to rest against stop plate 86B. The lifting of 53 also unlocks ring 66 by moving thev inner portion of lever 1| downwardly and leaves disc 55 free of the control of block 65, whereupon said disc returns to zero by traveling in the same direction as formerly under the action of motor 68 until pin 68 against contacts stop plate 86.

In the decoding operation, the reverse lever 11 and associated part locks the ring 66 against turning and the ring 8| prevents lever 1| from engaging the teeth of ring 65. If now, we take the letter R of the cryptograph message as a guide and depress the R key 32, disc 55 will travel all the way around to R position. The scanner in a reverse scanning operation of a plate 5 will have selected such stop 53 as the one to be dropped as will subtract five spaces or letters from R and block 65 will travel to that indicated point and be there stopped by pin 16 striking against the stop plate portion 53e of the dropped stop 53.

Such movement of block 65 will step disc 55 back five spaces because with ring 64 held against turning by an outside force (lever 11) rotation of 65 will act through lever 1| to turn stub shaft lill.l 'I'his will cause gears 62, 63, to turn on their shafts and will turn gear 58 in a direction reverse to the direction of rotation of block 65. Sincegear 56 is fast on shaft 51 such reverse movement will be imparted to disc 55.

Thus the M character instead of the R character on printing disc 55 is brought opposite hammer |02.

The element D in Figs. 1 and 12 represents a distributor which by the movement (manual or otherwise), of a contact arm |05 makes it possible to energize the. contacts of only one scanner unit at a time. As in the case of the scanner of Figs. 2 and 4 a scanner unit consists of that number of the pins 38 which coact with the perforations of a frame For example, in Fig. 7 we have illustrated a plurality of vertical columns upon a'shufileable card. Each column is divided vertically as previously described, into a plurality of frame spaces 6 and each frame space carries a group of perforations 1. There is room for five perforations in each frame but there are not necessarily ve perforations in each frame. For example, in the first frame at the upper left corner of Fig. 7 there are two perforations, two blank spaces and then a perforation. The scanner comprising the bar 30 (Figs. 2 and 4) is long enough to extend entirely across the card 5 and it carries as many groups of pins as there are columns upon the cards. However, as set forth with respect to the description of the operation of the scanner of Figs. 2, 4, and 6 only the five pins aligned with the perforatio-ns or spaces of a single frame can be operative at one time and this group of pins constitutes a scanner unit. Thus the scanner is the bar 30 with as many groups of five pins as there are columns and a scanner unit is the group of five pins operative with respect to the perforations in a single frame 6. By referring to Fig. 13, it will be seen that a common lead |06 from one side of .all of the contact members of a scanner unit leads through the contacts |00 and 40 to one of the contact points |01 of the distributor thence, through said arm |05 to battery |08, from the other side of the battery through a common lead Ii0l to the solenoids 50 and from the other side of said solenoids respectively back to the respective other contact members of said scanner units through leads |09. In like manner, the leads from the other scanner units are connected to the other contact points |01 of the disi tributor.

The magnets I6, I6, Figs. 1 and l13 are ener- Y.

gized when contacts I|0 and are closed by pawls I I2 and ||3 on the shank of key 82. These pawls are arranged to function on the up or return stroke o1' the key but not on the down stroke and H2 functions slightly in advance of H3 sos that the escapement of the pusher mechanism will function just ahead of the feed screw Having described our invention, what we claim is:

1. In a mechanism for recording a garbled rcryptographic message, the combination with a pack of plate-like separate coding units, capable of being shuffled with respect to each other, of

means for supporting said units in stacked relation, a scanner, means for effecting relative movement of the scanner and stack toward and from each other, a character forming mechanism, a manually operable key, means controlled by said key for imparting an initial movement to the character forming mechanism, means for actuating the character forming mechanism under control of the scanner, means carried by the plates and acting through the' scanner to modify the movement of the character forming mechanism in a relation determined by the disposition of said means upon the plates, -and means for shifting the scanned plate out of covering relation to the next succeeding plate.

2. A structure as recited in claim l wherein the plates are each provided with a plurality of frames, in each of which are disposed means to coact with the scanner and wherein the plate shifting meansis operable after each movement of the scanner and plates toward and from each other so that one frame of each plate is scanned successively through the stack and then another frame of each plate is scanned successively through the stack and so on.

3. The combination with a pack of plate-like separate coding units, of means for supporting said units in stacked relation, a scanner, means for eiecting relative movement of the scanner and stack toward and from each other, a character forming mechanism, a manually operable key, means controlled by said key for imparting an initial movement to the character forming mechanism, means for actuating the character forming mechanism under control oi the scanner, said plates having perforatlons formed therein, and said scanner comprising pins which seek to enter perforations of the plate, and means aiected by the movement of said pins for determining the effect of the actuating means of the character forming mechanism upon th latter mechanism.

4. A structure as recited in claim 1 wherein the plates are each provided with a plurality oi frames in each of which is formed a group o! perforations and wherein the scanner comprises a group of pins coacting with said perforations.

5. A structure as recited in claim 1 wherein the plates are each provided with a plurality of frames in each of which is formed a group of perfcrations and wherein the scanner comprises a group of pins coacting with said perforations, the plate shifting means being operable after eachmovement of the scanner and plates toward and from each other, so that one fra-me of each plate is scanned, then the plate is shifted, then one frame of the next plate is scanned and the latter plate shifted and so on -through the stack of plates. l

6. A structure as recited in claim l wherein each plate is provided with a plurality of frames disposed in columns, and wherein the scanner comprises a group of scanning units, and means for rendering all but one of said units inoperable during each movement of the scanner and plates to-ward each other.

7. A structure as recited in claim 1 wherein `the means for controlling the character forming mechanism by the action of the scanner includes electrically actuated members and electrical circuits for the same and wherein the scanner comprises a group of circuits closing elements for said circuits and wherein the plates are provided with group of perforations coacting with said circuit closing elements, the disposition of said perforations in their groups upon the plates determining which circuit closing element may function. Y

8. In a cryptographic machine a group of iiat -card like coding elements adapted to be shuiiied into many different relations to each other, a character carrying element, a manually operable key, means for causing a limited movement of said element under control of said key, a scan-v' ner coacting with said card like elements, means for shifting the said elements from covering position over the rest of said elements after the scanning of the same, means under control of the scanner for moving the character carrying element additively with respect to its first movement and means for returning both of said parts to initial starting position after each scanning operation.

9. A structure as recited in claim 8 wherein the scanner comprises a plurality of groups of scanner unitsand means for rendering all but one of the scanner units inoperative with respect to the character forming mechanism during each scanning operation.

10. A structure as recited in claim 8 wherein the scanner comprises a plurality of groups of electric circuit controlling elements, anda distributer included in said circuits,said distributer comprising a shiftable element acting to render operative one group, only, of the groups of circuit controlling elements.

11. A structure of the character described comprising a rst movable part carrying printing characters, power means tending to move said part, a second movable part, independent power means, tending to move said second movable part, a manually operable key, the movement of which releases said parts in succession, a stop set by the movement of said key to arrest the first part, after it has moved to a degree determined by the particular key that is actuated, a random key mechanism comprising a group of card like plates divided into frames, means within the frames for acting upon a scanner, a scanner movable over saidplates for scanning the means in the frames, a selector comprising a group of stops and controlled by the scanner, means for permitting the said rst part to move independently of the second part between the time of the release of the rst and the second -parts under the manipulation of said manually operable key, means for locking the rst and second parts to turn together after the second part is released, the movement of the second part under the inuence of its power means acting additively upon the iirst to move said first part a continued distance under the iniiuence of the movement ofthe second part, the degree of movement'of the second part, in turn, being limited by that one of the groups of stops which has been set through the selector and scanner.

12. A structure as recited in claim 11 in combination with means for releasing the stop of the rst named movable part by the setting of the stop of the second named movable part.

13. A structure as recited in claim 11 wherein the rst named movable part consists of a rotative disc having printing characters upon its periphery.

14. A mechanism of the character described comprising a rst and second rotative member, one of which comprises a disc having printing characters upon its periphery, a group of keys, one for each letter of the alphabet, a release mechanism for the said disc, power means tending to turn said disc and power means tending to turn the second rotative member, a group of stops arranged about said second part, a diierential mechanism connecting the first and second rotative members comprising a member, which when locked, eiects reverse movement of the disc with respect to the second movable part and a member under control of said group of stops acting to lock the iirst and second parts together during the formation of aV crytographic message and means for disconnecting the disc and the second movable part and for locking the movable member of the differential mechanism to thereby bring about a reverse movement of the disc under the inuence of the second movable member in the decoding of such a message.

15. In combination, a stack of plates divided into frames and having coding perforations in said frames, a scanner means for moving a scanner over` the frames of the plates successively, electric circuits controlled by the action of said scanner, which action is in turn controlled by the number and spacing of said perforations in the several frames, a selector comprising' a group of stops and electrically actuated members for actuating said selector under the influence of the scanner controlled circuits, a pair of rotative elements, the rst of which comprises a disc having printing characters upon its periphery, a shaft by which said disc is carried, a gear constituting an element of a differential mechanism i'lxed upon said shaft, said gear lying Within the second rotative element, a ring mounted to turn in said second rotative element carrying a pair of the gears of the differential, a stub shaft carrying the fourth gear of the differential,

a group of lock levers, one for each letter of the alphabet, cooperating with the stops of the selector, a reverse handle and means for locking the ring of the d iierential against movement when said reverse handle is manually actuated, to thereby bring about a reverse movement of the said disc which carries the printing characters.

16. In a machine for setting up garbled cryptographic messages, the combination with a character carrying printing element, of a manually operable key corresponding to a message character such as a letter of the alphabet, means for shifting the character carrying element to a printing point under control of said key, a group of card-like elements each carrying a plurality of groups of electric circuit controlling elements, a scanner cooperating with said circuit controlling elements, electric circuits controlled by said scanner as determined by the number and spacing of the circuit controlling elements of the cards in their respective groups, and means energized through said circuits for additively moving the character carrying printing element to a degree determined by which of the circuits are closed under the action of the scanner.

17. In a machine for setting up garbled cryptographic messages, the combination with a character carrying printing element, of a manually operable key corresponding to a message character such as a letter of the alphabet, means for shifting said element to a printing point under the control of said key, a group of plates capable of being shufed, each of said plates having a plurality of groups of perforations formed therethrough, a scanner cooperating with said perforations, electric circuits controlled by said scanner, the number or spacing of the perforations of every group upon a plate differing from the number or spacing of the perforations of every other group upon said plate, and means energized through the said electric circuits for additively moving the character carrying printing element to a degree determined by the circuits closed under the action of the scanner.

18. In a machine for setting up garbled cryptographic messages, the combination with a character carrying printing element, of a manually operable key corresponding to a message character such as a letter of the alphabet, means for shifting said element to a printing point under control of said key, means tending to move the printing element to a further point, a plurality of stops for limiting the movement of said element, a selector for determining which of said stops is to be actuated, said selector comprising a group of movable bars by which said stops are carried, electrically actuated means for controlling the movement of said bars, a plurality of electric circuits in which said electrically actuated means are included, a scanner comprising circuit closing means for said circuits and perforated elements scanned by said scanner, said perforations being disposed in a plurality of frames, there being a plurality of perforations in each frame, the number and spacing of the perforations in any given frame determining which circuits will be closed under the action of the scanner.

19. In a cryptographic message forming mechanism and control means therefor, the combination with a group of card-like units adapted to be shuiiied and stacked as independent elements after the manner of cards, each having its area divided into a plurality of frame spaces, said frame spaces being provided with groups of perforations arranged in varying random orders, of a scanner, means for periodically moving the scanner toward and from the end card of the stack, means for shifting the end card of the stack out of covering position with respect to the stack after each advance of the scanner theretoward, the scanner comprising electric circuit closing means coacting with the perforations of the card, a message forming mechanism, an actuating means for said mechanism, and electric circuits including the electric circuit closing means of the scanner and through which the actuating means of the message forming mechansm is varably controlled to form cryptographic messages of a nature determined by the order of the perforations in the frame spaces, the shifting of the end card out of covering position with respect to the stack after each advance of the scanner theretoward permitting the scanning of only one frame of a card, then another frame of the next card, and so on throughout the stack, to thereby form the successive characters of the cryptographic message.

JOSEPH B. WALKER. SHELDON K. JOHNSON.

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