US2458734A - Mechanical ciphering system - Google Patents

Description

A. H. REIBER 2,458,734

MECHANI CAL CIPHERING SYSTEM Jan. 11, 1949.

Filed D90. 8, 1945 2 Sheets-Sheet l in ///////l 78 mm i INVENTOR ALBERT H. REIBER, DECEASED 'EMI'LY Y. REIBER, EXECUTRIX AT ORNEY A. H. REIBER MECHANICAL C IPHERING SYSTEM Jan. H, 1949.

2 Sheets-Sheet 2 Filed Dec. 8, 1943 mvm'o R ALBERT H. REIBER, DECEASED EMILY Y.YRE IBER. EXECUTRIX ATORNEY Patented Jan. 11, 1949 by Emily Y. Reiber, exeeutrix, Evan'ston, 111., assignor to Teletype Corporation, Chicago, Ill., a

corporation of Delaware Application December 8, 1943, Serial No. 513,874

2 Claims. (01. its-=22) This invention pertains to printing telegraph receivers and particularly to an apparatus for the reception of secret or confidential telegraph messages.

Signaling systems are desirable for naval, military, and civil purposes wherein it is required that messages be rendered unintelligible to persons unauthorized to receive them. surreptitious interception of messages may be accomplished, for example, in the case of the Wire communication by tapping signal wires, and in radio communication by means of receiving apparatus tuned to the proper frequency.

The primary object of the present invention is the provision of a simple, compact, and eflicient apparatus for rendering messages unintelligible to unauthorized persons.

Another object of the invention is to provide a system or apparatus for precluding the unauthorized interception of intelligible messages by 1 mechanical operation established in response to the respective control conditions.

A further object of the invention is to provide a deciphering instrumentality which is readily adaptable to commercially available printing telegraph apparatus.

Specifically, the apparatus according to the present invention is utilized to decipher and record previously enciphered messages which have been transmitted from a remote station. In order to encipher messages according to the present system, the elements of the code combinations of the original, intelligible message are combined with the elements of code combinations provided by a key tape or other control mechanism. In such arrangement, opposite conditions (that is, one element of the original code combination marking and the corresponding element of the key code combination spacing) produce a marking signal. Like conditions, however, with both elements marking or both elements spacing, produce spacing signals. This presumes, of course, that each of the elements of the respective code combinations are related to each other. That is, the No. 1 element of the original code combination is combined with the No. 1 element of the key code combination, and so forth. To take a specific illustration, let it be assumed thatit is desired to encipher the character R which in the Baudot code is composed consecutively of spacing, marking, spacing, marking, and spacing conditions. Let it be further assumed that the key tape with which the particular enciphering operation is to be performed occupies a positioii whereat it is conditioned for produoihg the letter Y combination, which in the Baudot code is composed consecw tively of I marking, "spacing, marking, spacing, and marking conditions. Under the assumed conditions, the encipherin-g operation would restill, in the PTOCIUEtiOh of an all markin or Letters combination, since in this particular illustration o posite conditions or an the related elements of FR and Y code combinations are provided. This will be 'i'eadil-y apparent rro'm the following chart Whei 'eih the letter M indic'ates 'a marking condition and the letter S indicates a spacing condition:

Original Signal R S M. s M s KeySignaWY M s M s M M M M M It is understood that both the transmitting and receiving end of a telegraph line will be equipped with identical key tapes which during message transmission will occupy identical positions. During transmission the key tapes are advanced between characters to modify the key signal, but both tapes "occupy the same corre spohding positions at all times. A station which receives enciphe'red signals is thus enabled to decipher the unintelligible signals transmitted over the telegraph line by combining the enciphered signals with key -signals provided by its key tape.

To illustrate a deciphering operation, the exa-inple g'i'veii above in connection with the en- 'ciphering operation will be continued, and it will be assumed that a receiving station received the enciphered signal; namely, Letters. The Y combination provided by the key tape at the receiving station can now be combined with the received Letters combination to decipher the enciphei'ed signal to thereby reproduce the orig-"- inal signal R," as clearly shown in the followin'g chart:

Ehciphred Signal Letters M M M K- ey'Signal Y. M M Original Signal R" M S S A more complete understanding or the invenmen may be has from the renewing description aken iii conjunction with the accompanying drawings, wherein: V

Fig. 1 is a front elevatioh'al view of the re- Fig. 5 is an enlarged fragmental view showing I the essential elements of the deciphering device and graph system embodying the present invention.

The deciphering mechanism according to the present invention is illustrated in the figures as applied to a. type wheel printer of the type shown Fig. 6 is an electrical circuit diagram of a tele- I in copending application SerialNo. 397,193, filed June 9, 1941, by W. J. Zenner. framework is indicated at H and comprises side frames l2 and I3. Mounted on the side frames l2 and I3 are journal brackets l4 and I5 which support the main cam shaft l8. Also spanning the frames l2 and |3is a plate ll, which carries a series of five electromagnets Hi, '21}, 2|, 22, and 23 mounted on a bracket 24 and which constitutes part of the decipheringmechanism according to the present invention. Journaled in the side frames l2 and I3 and extending therebetween is a pivot shaft 25. Pivotally carried on the pivot shaft 25 substantially midway between the frames l2 and I3 is a printing arm 26 which carries at its extremity. (the left end as viewed in Fig. 3) a platen member 21.

Platen member 27 cooperates with a type wheel segment 28 fixed to a type wheel shaft 29 journaled in a bearing 38 mounted in a plate 35 which spans the frames l2 and i3. The type segment 28 is provided with four rows of type faces; and a shift mechanism therefor is exemplified by a plurality of stop bars 33, provided for controlling the shifting movement of the type segment 28 to effect printing from the various rows of type. The bracket 34 is provided for guiding and supporting the tape between the platen 21 and the type segment 28. A spring 35. normally biases the type or printing arm 26 downwardly to hold the platen, 2'! free from the type segment 28. The printing operation is effectuated through the instrumentality of the vertical link 36 extending from the printing arm 26 and a printing cam (not shown) carried on the main shaft l6. Carried in brackets 31 (one of which is shown in Figs. 3 and 5) mounted on plate ll is a pivot shaft 39 on which are pivotally carried a series of selector levers 4| to 45. Each of the levers 4| to 45 is provided witha cam follower projection 46 which cooperates with the periphery of an associated selector cam 41. There are five such cams 41, one associated with each of the five selector levers 4| to 45. The cams 4'! are of similar cam contour but are displaced on the shaft l6 angularly so that the cam notches 48 are disposed in a helically arranged series whereby coaction with the cam followers 46 will occur in a sequential manner as the series of cams 41 rotates in synchronism with the speed of code impulsing. The levers 4| to 45 are normally biased in a clockwise direction about the pivot shaft 39 by individual springs 49.

The extremities 52 of the levers 4| to 45 cooperate with a shoulder 53 of an associated selector bar 54. Bars 54 are positioned vertically in the printer mechanism and are mounted on a shaft 55. Each of the bars'54' is provided with a slotted hole 55 cooperating with the shaft 55 so The printer;

that an individual spring 51 associated with each of the bars 54 tends to hold the bar 54 in its vertical position against the bottom of the slot 56. The vertical bars 54 are provided with a series of notches on one edge thereof and cooperate with a plurality of function bars 58 in the manner described in the copending Zenner application.

J uxtapositioned to each of the selector levers 4| and 45 is a companion bar 59 which is slidably mounted with respect to its associated lever 4| to v 45 on pivot shaft 39 and a stud 6| fixed to said associated lever. Each of the companion bars 59 is provided at its left-hand extremity (as viewed in Fig. 3) with a vertically projecting portion H, and at its right end with a horizontally extending portion 12. Each of the bars 59 is normally. biased rightwardly (as viewed in Fig. 3) by a spring 73 individual thereto, which extends between depending lugs on bar 59 and its associated levers 4| to 45. I

Extremities 72 of each of the bars 59 cooperate with the armature 14 of each of the deciphering magnets l9 to 23. Armatures 14, when seized by their respective magnets l9 to 23, extend their individual springs 15', and thus permit springs 13 to urge or bias'their respective bars 59 to the rightward position, as shown in Fig. 3. When the magnets l9 to 23 are de-energized, their individual springs 15 rotate the armatures 14 to their clockwise position, as shown in Fig. 5. Springs 15 are stronger than the springs 13, so that when the magnets I9 to 23 are de-enegized, the springs 15, through armatures 14, will urge the bars 59 leftwardly against the action of biasing springs 13.

The vertically extending portions H of the bars 59 cooperate with the armature 16 of electromagnet TI. The magnet H is the single 'line magnet of the receiving selector mechanism and responds successively to the code signal impulses. The line magnet 11 is suitably mounted on a bracket l8. The armature 16 of magnet TI is pivoted at 19, and a spring 8| normally tends to rotate the armature 16 in a clockwise direction about the pivot l9 when the magnet 11 is deenergized. An adjustable stop screw 82 is provided to limit the clockwise movement of the armature 15 so as to correspond to the leftward movement of the bars 59 by the armatures 14. As shown in Fig. l, the lower extremity of armature l6 spans all of the projections l I.

As illustrated in Fig. 2, the cams 4! are carried on a sleeve 83 which is drivingly connected to shaft l6 by means of a friction clutch. Shaft l6 derives its power from a motor 84 through a pinion 85 and a gear 86. The cam assembly on shaft l5 also includes a cam 81 which acts upon a bell crank lever 88 to cause an extension 89 thereof to act upon all of the bars 54 to return them leftwardly to their normal unlatched position (as shown in Fig. 3), thus disengaging those members 54 which areengaged by the end 52 as will presently be described, and permitting them to be returned by their springs 51 to their upward normal position, with the shaft 55 at the bottom of the slot 56.

General operation In the operation of the apparatus according to the present invention, it is assumed'that the normal stop current on the line 9| (Fig. 6) is marking, in which condition the armature 16 will be seized, and the cam sleeve 83 on shaft IE will be blocked against movement in Well-known manner in start-stop operation. The electrobe sensed by a record reader or tape sensing device to control the transmission of code combinations of signal impulses to the electroma nets l9to 23. Upon receipt of the start impulse, which in the present illustration is a no-current impulse, the magnet 11 will be tie-energized, thus releasing armaturefldwhich responds to the pull of the spring 8|. This action initiates the rotation of the sleeve 83 in well-known manner. The cams .41'wi11 then sequentially allow the leversjil to 4 5 to respond to the pull of their respective springs 49 unless said levers are fblocked through the coaction of portions 1! and armature 15. For example, assuming that the lever 43 (through projection 1|) is not blocked, :its cam follower portion 46 will fall into the depression in its respective cam 41 and lever 43 will be caused to rotate slightly in a clockwise "direction. That is, if the lug 1a is not obstructed by'the armature 16 when the portion 46 of lever 43 engages a cam notch 48, the lever 43 will be free to rotate clockwise to bring the end 52 there- ;of out of the path of shoulder 53 of lever 54 to permit the spring 51 thereof to rotate said lever '54 to bring the shoulder 53 under the extremity 52. Then, when the cam 41 rotates further to cause itshigh portion to urge the lever 43 counterclockwise, the bar 54 will be depressed against the action of its spring 51.

" 'Unde'r'certain conditions of operation, in response to predetermined code signals, certain 'ofthe bars 54 will function to operate certain of the stop bars 33 to control the shift movement of the type 'wheel 28 to cause printing in a selected one of the four rows of type. This specific mechanism is fully described in said copending Zenner application.

Of course, if the projections 1| are blocked by the armature 16 no clockwise rotation of levers 4| to 45 will occur and, hence, the bars 54 associated therewith will not be operated downwardly. As previously described, cam 81 will act through ball 89 to disengage the operated bars 54 from the extremities 52 of the levers 4| to 45 with which they have'become engaged,

whereupon the respective bars 54 will be raised by their springs 51 to the position shown in 'Fig. 3.

" In the operation of the deciphering arrangement according to the present invention, the levers 4| to 45 are controlled jointly by the selector electromagnet 11 and by the deciphering electromagnets |9 to 23. Having reference to Figs.3 and 5, when the signal impulse received by the selector magnet 11 is of a marking nature, the magnet 11 will be energized and the armature 15 will be attracted, or moved to its position shown in Fig. 3, to bring its lower extremity into a position to cooperate with the lug 1| (of any one of the bars 59) when the bar 59 is in its rightward position. Under normal conditions of operation when the printer mechanism is employed for recording intelligible messages, the levers 4| to 45 are controlled solely by the selector magnet 11, so that clockwise rotation of the levers 4| to 45 sequentially under the con- W trol of cam 41 is controlled by the armature 16 such that "when the armature 16 in its attracted position obstructs the projection 1| the cam follower 46 of levers 4| to 45 associated therewith will not fall into the notch 48 of the cam 41.

,igvhen the armaturelfi isout of. the path ofthe ,projectien 1| the .levers M .to 45 will respond to the pull' of. their springs 1.49 and clockwise rotation will resnltto blf i the extremity 52 of a 1ever. 4|fto45 abovthe shoulder 53' of its associated bail-i4, and" in engagement therewith 'so that subsequent rotation of cam 41 will depress the arm 54 engaged with the levers 4| 11045.

,However, under thecontrol of the deciphering arrangement according to the present invention, .the movement of levers 4| to 45 will be further governed by the deciphering device, ex-

emplified by magnets l9 to 23, inclusive. In the position illustrated in Fig. 3, the deciphering .magnet 2| is shown energized under the controlof the-ke'y'tape 92, in which condition the armature 14 is attracted, whereupon the bar 59 isactuated by spring 13 to its rightward position'to bring the vertically extending portion 1| 43 in Fig.3), through projection 1|, will be blocked against operation under control of cams 41.

Having reference to Fig. 5, the four difierent conditions of operations under the joint control of .the deciphering magnets I9 to 23 and the selector magnet 11 will be described. The con- .ditioniof operation shown in Fig. 3 is exemplified in Fig. 5 with the armatures 16 and 14 in their dotted line positions. Under this condition of operation the lever 43 will not be permitted to rotate clockwise and hence its corresponding bar 54 will not be operated.

According to a second condition of operation let it be assumed that the magnet 11 is energized by a marking impulse and that the deciphering margnet 2| is de-energized, so that armature 16 assumes its dotted line position and armature 14 assumes its solid line position in Fig. 5. Due to this control, the bar 59 is actuated to its leftward position by reason of the fact that the spring 15 preponderates the weaker spring 13. Thus, the vertical projection 1| is moved out of vertical alignment with the armature 16 so that upon rotation of cam 41 the lever 43 associated .tremity 52 will be elevated to permit the shoulder 53 of bar 54 to be introduced therebeneath so that when the high portion of the cam 41 actuates the lever 43 counterclockwise, the bar 54 will be urged downwardly.

Under a third condition of operation, it is assumed that the deciphering magnet 2| is deenergized, and that the bar 59 is maintained in its leftwise position by the stronger spring 15; and further that the selector magnet 11 has heen de-energized in response to a spacing signal, whereupon armature 16 is rotated clockwise (to'its solid line position) by its spring 8| into engagement with stop 82 to bring the lower extremityof armature 16 into the path of the vertical portion 1|. Thus, when cam 41 rotates, the cam follower projection 46 is prevented from falling into the notch 48- of the cam 41 due to said engagement of portion 1| with armature 16. Hence, it is seen that when any of the deciphering magnets 2| to 25 is conditioned in response to a spacing signal and the line magnet 11 is similarly conditioned, the resultant condition is a spacing condition; that is, levers M to 45 (lever 43 in this particular instance) are not operated in response to the rotation of cam 41.

Under a fourth condition of operation, the deciphering magnet 21 is energized, thus causin the armature I l to be attracted to the dotted line position shown in Fig. 5, and thereby permitting the spring 13 to actuate the bar 59 to its rightward position bringing the vertical portion II to the dotted line position. Also, under this condition of operation the selector magnet I7 is de-en-ergized in response to a spacing signal and armature I6 will assume the solidline position shown in Fig. 5. It will be observed, then, that the projection II is not blocked by the armature 76 since the armature is in the solid line position and the lug IE is in the dotted line position in Fig. Therefore, upon rotation of cam in, the cam follower projection 46 will fall int-o the notch 48, thus imparting clockwise rotation to lever 43 (since projection H is not obstructed). Accordingly, the extremity 52 will be brought above the shoulder 53 and lever 54 will be biased inwardly by its spring 51 so that bar 54 will thereafter be operated under the control of cam 41.

With the. mechanism just described it is seen thatwhen the selector magnet 11 and deciphering magnet 2| (or any one of the deciphering magnets I9 to 23) assume the same conditions, namely, both marking 01' bothspacing, the lever 43 operates as. it would in response to a spacin signal if it were solely under the control of the selector magnet "I7. On the other hand, if the selector magnet 71 and deciphering magnet ZI are operated in opposite manner, the lever 43 responds as it would for a marking signal if it were solely under the control of the selector magnet l'I, which condition conforms to the tables presented hereinbefore.

Electrical circuit In Fig. 6 is shown an electrical circuit or diagram of a system embodying the receiver according to the present invention. In the rectangl-e ml is shown a set of transmitting contacts I02 such as are associated with a rotary cam distributor (or other type of distributor), and a series of contacts 103 which are controlled, in the present embodiment of the invention, by a key tape IM. It is, of course, understood that any other form of control mechanism for operating the contacts IE3 is contemplated. It is noted that each of the contacts I03 is connected to a solenoid I05, and that the contacts I02 were included in a circuit extending from ground, through battery, then through the contacts I02 sequentially, over the line conductor 9|, and through the winding of the selector magnet TI to ground. Such a transmitter is disclosed in copending application Serial No. 496,552, filed July 29, 1943, by A. H. Reiber.

The magnet H is shown as included in a receiving station indicated by the rectangle I05, and the armature T6 and bars 59 are shown diagrammatically. Also shown associated with the bars 59 are the deciphering electromagnets IS to 23, inclusive. Magnets I9 to23 are included in a circuit extending from a common ground Wire to their respective contacts I07 governed by tape controlled levers I08, thence to grounded battery. It is understood that control mechanisms other than such as are controlled by tape may be employed in carrying out the present invention. The stepping of the tape is, of course, presumed to be effected cyclically in phase with the transmission and reception of code signals.

As previously mentioned, identical key tapes I04 and 92 (or identical control mechanisms of any other type) are provided at the transmitting and receiving stations IDI and I06, respectively. It is understood that these control mechanisms are placed in their respective station units in identical positions so that in the operation of the machine the transmitting apparatus contacts I02 and the selector magnet 'I'I shall have their selective operations altered in a uniform manner.

Although a specific embodiment of the invention has been disclosed, it is understood that the invention is not to be restricted to the structure herein described but is to be given an interpretation determined by the scope of the appended claims.

What is claimed is:

1. In a recorder, cam means, a plurality of instrumentalities carried on a common pivot and adapt-ed to be operated in a predetermined manner by said cam means, signal controlled means, deciphering means, a corresponding plurality of elements carried on said pivot and dually controlled by said signal controlled means and said deciphering means forexercising control over said instrumentalities, each of said elements being slidably articulated to and in juxtaposition with an associated instrumentality, and selectable members operated by said instrumentalities according to the control exercised by said elements.

2. In combination, a selector including a plurality of cams, a follower associated with and urged into engagement with each of said cams, said cams having low portions for receiving the cam followers followed by raised portions for actuating the followers invariably, a pivot for supporting said followers, signal responsive means normally operable selectively to block the followers from engagement with the low portions of their cams, deciphering means, a correspond ing plurality of elements carried on said pivot and dually controlled by said signal responsive means and said deciphering means for exercising control over said followers, each of said elements being slidably articulated to and in juxtaposition with an associated follower, and a slidable actuator associated with each follower for actuation thereby, said actuators operated by said followers according to the control exercised by said elements.

. EMILY Y. REIBER, Emecutria: Under the Last Will and Testament of Albert H. Reiber, Deceased. 1

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Hagelin Feb. 12, 1946

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