US2525941A

US2525941A - Mechanical ciphering unit

Info

Publication number: US2525941A
Application number: US776526A
Authority: US
Inventors: Martha W C Potts
Original assignee: Teletype Corp
Current assignee: AT&T Teletype Corp
Priority date: 1946-10-10
Filing date: 1947-09-27
Publication date: 1950-10-17
Anticipated expiration: 1967-10-17

Description

Oct. 17, 195 L.. M. PoTTs 2,525,941

MECHANICAL CIPHERING UNIT Original Filed OCT.. 10, 1946 2 Sheets-Sheet 1 Louis M. PoTTs, osceAsEn MARTHA w. c. PoTTs, execumx ATTORNEY Ont. 17, 1950 L. M. PoTTs 2,525,941

MECHANICAL GIPHERING UNIT Original Filed Oct. l0, 1946 2 Sheets-Sheet 2 FIG. 3 38 46 INVENTOR LOUIS M. POTTS, DECEASED MARTHA W. C.POTTS, EXECUTRIX ATTORNEY Patented Oct. i7, 1950 UNITED STATES PATENT GFFICE MECHANICAL CIPHERING UNIT Original application October 10, 1946, Serial No.

Divided and this application Septembei' 27, 1947, Serial No. 776,526

Claims. l

This invention relates to secret printing telegraph apparatus and particularly to mechanical ciphering units for enciphering and deciphering telegraph messages.

This application is a division of copending application Serial No. 762,429, filed October 10, 1946, matured into Patent No. 2,522,461.

The primary object of the invention is the provision of mechanical ciphering units for secreiI telegraph message communication.

Another object of the invention is to provide a mechanical ciphering unit including a mechanical chain linkage system in which variable paths oi movement through the linkage are afforded for ciphering operations.

An additional object of the invention is the incorporation of a mechanical ciphering chain system in a type Wheel printer.

A feature of the invention is to provide a ciphering type wheel printer which is all mechanical in operation and requires no motor, all power being furnished from the keyboard,

In general, it is proposed to provide, in combination with a, ve unit code selector which includes ve mechanical selectable elements positionable to two different positions, a variable mechanical chain or each selectable element. The positions of certain component parts of the chains are varied so that motion transmitted through the individual chains follows a variable path which ultimately determines the positions occupied by the selectable elements. To achieve such a result each mechanical chain includes a plurality of pairs of slides which cooperate with a plurality of pairs of ciphering levers Whose positions are determined by the setting of cam pairs of ciphering code drums which may be stepped to a number of different positions. The code drum cams are cut so that the high parts of one cam are opposite the lovi7 parts or notches of the companion member of the same pair of cams. This insures that the ciphering levers oi any pair will always be oppositely positioned for operation to provide a continuous path of movement through the mechanical chains as will be more fully described later in the specification.

One embodiment of the invention utilizes mechanical ciphering chains in connection with a keyboard operated type wheel printer. The stopping position o the type wheel is determined by the selection of a stop pin, by means of a five unit code disc selector similar to the selector disclosed in the Morton et al. Patent N o. 1,821,110. The positioning oi the code discs is determined by the operation of the mechanical ciphering chains, there being one chain for each element of the code. In this instance, an enciphered message can be typed on a tape and then sent by telegraph, courier, or other means to a predetermined destination. An attendant at this destination by employing an identical type wheel printer may retype the received message which will then be deciphered and printed in plain English. lt is, of course, assumed that both type wheel printers would be provided with identically cut key code drums which will occupy the same relative positions during the enciphering and deciphering operation. An additional advantage oi the type Wheel printer herein disclosed is that its operation is all mechanically controlled from the keyboard and requires no motor.

A better Iunderstanding of the invention may be had by reference to the detailed description which follows when read with the accompanying drawings wherein:

Fig. 1 is a fragmentary iront elevational view particularly illustrating the functional operations of the type Wheel printer;

Fig. 2 is a fragmentary front elevational View particularly illustrating the operation of the selector mechanism of the type wheel printer;

Fig. 3 is an end view of the apparatus taken on the line 3--3 of Fig. 1;

Fig. 4 is an end View of the apparatus taken on the line 4 4 of Fig. l

Fig. 5 is a partial iront view of the apparatus showing particularly the locking plate for the ciphering code drums;

Fig. `6 is an enlarged detailed perspective View of the mechanism for operating the type wheel; and

Fig. 7 is an enlarged detail View oi a key slide blank.

Referring now to Figs. 1 to 7, inclusive, the embodiment of the invention which is devoted to the type Wheel printer will now be described. Referring to the parts by reference numerals, 3l represents the base of the apparatus upon which is supported in any suitable manner a housing d2 composed of front and rear Walls 33 and 3d, respectively, end Walls 36 and 3l', and a top portion 38. Within the housing 32 are mounted a iront supporting member 39, an intermediate supporting member lll secured to member 39 by means of bolts 25, and a rear supporting member 42 integrally formed as part of the front supporting member 39 in a slotted guide i3 (Fig. 5). Similarly the rear supporting member l2 is provided With a slotted guide, not shown, and belby associated springs 4E.

tween it and the slotted guide 43 are mounted for slidable vertical movement a series of key slides 44 normally urged to an upward position All the key slides 44 may be cut from the same blank as shown in Fig. 7 by cutting off the undesired upward projections 4l' according to the row of keyboard 4B in which it is desired to place the particular key slide. For example, if it were desired to make a particular key slide 44 operable from the front row of keyboard 48 the middle and rear upward projections 41 would be cut off at 49. The key slides 44 also include a centrally located and downwardly depending portion 5I, designed to move in a lower guideway 52 which is suitably attached to the intermediate supporting member 4I, while the middle upwardly extending projection 49 is designed to ride in the upper guideway 5E) also mounted on member 4I. Keyboard 48 is provided with the usual space bar 53 Vpivoteol on each side at 54 and normally urged in an upward direction by springs, not shown.

Mounted below the key slides 44 for horizontal slidable movement on rods 56 and 5l are five pairs of permutation bars 58F, 555B. Each pair of permutation bars is composed of a front bar 58F and av rear bar SSR, the front bars EBF being normally urged to the right as viewed in Fig. 2 by means of springs 59?, while the rear bars 58B are similarly urged to the right by springsvQR. The permutation bars EF, 58B. are respectively provided with upwardly extending beveled cam projections GIF and GIR designed to be engaged by the lower edges of key slides 44 and are so arranged that for any given pair of bars 58F and 58Hl only one of the pair will move to the left when a key slide 44 is depressed. In other words, Where there is a projection @IF on a bar SEF there will be no projection 6 IR at a similar point on bar 58B, of the same pair and vice versa.

It will be understood that although the operation of only one mechanical chain will now be described there will be a similar chain for each element of the five unit code. Each of the permutation bars 58E, 53F is provided near` its left end (as viewed in Fig. 2) with a notch 52, in which the upper arms GSF, SSR of a pair of operating levers MF, 64B, pivoted at 63 are nested. Operating lever tllF is designed to engage at its lower end a rearwardly extending lug F of slide 68F while operating lever 64B, is designed to engage at its lower end a irontwardly extending lug 61B, of slide R. Pivotally mounted in socket G9 of slide 68F is a ciphering lever 'HF which is urged in aA counterclockwise or upward direction by means of its associated spring 12F. Ciphering lever lIR, is similarly mounted on the slide EiBR.

The positions of the pairs of ciphering levers I IF, 'I IR, are determined by the positions of associated pairs of sensing levers 13E, 'I3Rwhich are pivoted at 'I4 and which by means of projections sense the periphery of associated cam pairs TIF, TIR of code drums 60. Cam pairs TEF, I1-R are so notched that the 'high parts of cam HF of one pair are directly opposite the low parts or notches of the other cam 'VIR of the same pair. The periphery of the cam pairs TIF, 'VFR may be cut in a fortuitous manner. The just described cutting of the cam pairs insures that ciphering levers "HF, 'IIR of any pair of ciphering levers will always be oppositely positioned. The free end of ciphering lever 'IIF or 'IIR is designed to engage either the rearwardly extending lug TSF of slide 'IF or the frontwardly extending lug 'I8R of slide TSR, depending upon the notching of the cam pairs TIF, TER. Thus if ciphering levers 'HF is down, as shown in Fig. 2, it will be in a position to engage a lug 'ISF of slide TIS F. At this time ciphering lever 'IIR will be up or in a position to engage a lug lSR, of slide HSR.

The second code drum 'it is composed of cam pairs SIF, SER which by means of sensing levers 82F, 82B, control the positions of ciphering levers BSF, 83B, respectively mounted for pivotal movement on slides iSF, MR. Likewise, a third code drum Bil composed of cam pairs Sill-e, 84B. by means of sensing levers SBF, 8d3, control the positions of ciphering leversv BTIF, SlR pivotally carried by their respective slides SBF, 88B.. The free ends of ciphering-levers SBF, SSR may engage either the rearwardly extending lug SQF of slide 88F or the frontwardly extending lug 89B. of slide SSR. The free end of ciphering levers i'ilF, NR may engage either the rearwardly extending lug SIF of marking slide 92M- or the frontwardly extending lug SIR of spacing slide $25. Marking slide M is designed to engage arm 93 of transfer' lever S4 pivoted at 96, while spacing slide 92S is designed to engage arm 91 of transfer lever 94. Transfer lever Q4 includes a rounded third arm Q8, which is nested in notchY SQ of an individual selector disc Il ci a five unit disc selector I2. Discs IUI are freely mounted on shaft H33. Movement of a marking slide 62M will, therefore, move an individual selector disc IUI to a marking position and movement of a spacing slide 92S will move an individual selector disc I'I to its spacing position.

At right angles to and equally placed along the circumference of the selector disc lill and guided in guide plate I U4 (Fig. '3) are the usual stop pins IGS. rFhis type of five unit selector is well known in the art and is fully described in the patent of Morton et al previously referred to above. When the V-shaped slots IB'I of selector discs Il!! adjacent a particular stop pin |06 are in alignment, this pin will pivot inwardly due to the force exerted by garter spring |58 and assume a position to stop movement of the type wheel stop arm led as will later appear.

It can now be readily seen that when a key slide 44 is depressed one of the operating levers 64F, 54B, of each pair'will pivot at i in a counterclockwise direction and at its lower end push against one of the slides 68E', GSR moving it to the right. The positions of cipering levers TIF, 'HR will determine which of the slides TSF, 'ISR will be operated, the positions of ciphering levers 83E', 83H will determine which of the slides 88F, SSR will be operated, and the positions of ciphering levers E'IF, STR, will determine whether a marking slide 92M or a spacing slide 92S will be operated to position the individual selector discs II accordingly. Since the code drums 69, i0, Il!) are stepped to different positions as will later be described it is obvious that the path of movement afforded for each mechanical chain will vary with the setting or" the code drums.

Positioned below all the key slides 44 for engagement by any one of them, after selected permutation bars 58 have been moved to the left as previously explained, is a universal bar III (Fig. l). The universal bar III is attached to end pieces ile which are welded to the key slides 44 located at either end of the series of key slides. The key slides 44 which support the universal bar Il I will have all three upward projections 47 cut therefrom at lig (Fig. 7) since in this case such projections are unnecessary. The universal bar II I is normally held in an upward position by springs 46 which are provided on all key slides 44.

As the universal bar III moves downward when engaged by a particular key slide 44 it strikes the laterally extending arm of a bell crank ||2 which is pivoted at IIS. This causes the engagement of the upwardly extending arm of bell crank i2 with a bent over flange I I4 of m-ain operating slide I I6, causing the slide H6 to move to the right as Viewed in Fig. l against the tension of a relatively strong spring ||1. The slide ||6 is mounted for horizontal movement by means of pin and slot connections |65, ||5.

The stepping of the code drums 66, 10, and 86 through actuation of the main operating slide ||6 will now be explained. It should be mentioned that it is proposed that each code drum may be stepped to twenty-six diierent positions. The rst code drum 66 is carried by sleeve 66 which is rotatably supported on fixed shaft ||6 suitably attached to the rear supporting member 42. Integral with sleeve |96 is a raised annular disc |64 in which are seated dowel pins |56 which extend through flange |55 of a second sleeve |56 mounted for rotation on fixed shaft I I8, through ratchet H9, through disc |23 and spacer |65. Thus when ratchet i i6 is rotated cam pairs 11F, 11R of code drum 66 will be rotated therewith. The dowel pins |56 are removable and provide means whereby adjustment of the cam pairs may be made. It is to be understood that code drums 16 and 66 will be respectively mounted in a similar manner on fixed shafts A|29 and Pawl |26 is urged into engagement with the teeth of ratchet SIS by means of a spring |22. Mounted adjacent to ratchet ||9 for movement therewith is the disc |23 having a deep notch |24. As ratchet H9 is stepped by pawl |2I due to the reciprocation of slide |56 a position will be reached whereat lug |26 formed as an integral part of a stepping pawl |21 pivoted at |26 will enter the notch |24 of disc |23 allowing this pawl to step ratchet |23, thereby causing movement of sleeve |66 and the consequent stepping of five pairs of cams 3 |l1, SIR comprising code drum Secured on a sleeve |66 rotatable on fixed shaft |26 is a dise I3! having a notch |32 which at one position in its rotation will be engaged by a lug |33 integral with stepping pawl |34 pivoted at |36 to the main operating slide H6. Pawl |34 is urged into engagement with the teeth ci ratchet |33' by means of a spring |36. Ratchet |31 is secured on a sleeve |66 rotatably mounted on fixed shaft |39 and drives the five pairs of cams 84E', 84B. The code drums may thus provide 17,576 (26 to the third power) key ciphering selections without repetition since there are 26 teeth in each of the ratchets H6, |28, and i3?. Increasing the number of code drums and thus lengthening the chains would, of course, increase the number of key selections.

Gear segment |46 engages at its toothed portion |54 a pinion |56 attached to shaft |51 which is mounted in bushings |45. Shaft |51 carries type wheel |58 and stop arm |66, each being connected to the shaft |51 by means of sleeve |59. It should be noted that normally the force exerted by spring ||1 on operating slide ||6 through rack |43, pinion |44, gear segment |49, and pinion |56 holds stop yarm |09 against a xed stop member |62. This gearing arrangement just described which drives stop arm |69 is of a very high ratio so that a small movement of slide i I6 enables a relatively greater movement of the stop arm which is capable of movement until blocked by any selected pin |66 as will now be described. By means of adjustable plate |4| the operative position of rack |43 with respect to pinion |44 may be varied.

The play allowed between lug |52 of shaft |48 and notch |53 of hub |46 insures that the stop arm |65 may move to any of its positions according to the selection of a, particular stop pin |66 and still allow further movement of the main operating slide ||6 to complete other functions. Thus when a. key slide 44 is depressed and slide |6Vmoves to the left as viewed in Fig 6, rack |43 will rotate pinion |44 counterclockwise causing notch |53 to tend to move away from lug |52. However, the force of spring |5| acting on gear segment |49 attached to shaft |48 enables the lug |52 to follow notch |53 until stop arm |69 encounters the selected stop pin I6. It should be remembered that universal bar is not operated until a selection is made as has already been pointed out, and therefore, a stop pin |66 will be selected prior to movement of stop arm |66. When the stop pin |56 is encountered by stop arm |65 further movement of slide I6 to the left is permitted due to the play between lug |52 and notch |53. The amount of additional movement of slide ||6 after a pin |66 is encoun tered is determined, of course, by which pin is selected. If the nearest pin to the stop arm |69 is selected there will be a maximum of further movement of slide I I6, Whereas if the furtherest pin |66 is selected there will be a minimum ci additional movement.

A description of the printing and tape feeding tape operations will now be undertaken. Suitably pivoted at |63 to a xed part of the apparatus is a bell crank I 64 having an upstanding arm |65, the upper end of which rests between pins |66 attached to the main operating slide H6. To the laterally extending arm |61 of bell crank |64 is pivoted at |68 a pawl |69. Also carried by arm |61 of bell crank |64 is a tape stepping pawl |1I which is pivoted at |12. Pawls |69 and |1| are urged in opposite directions about their pivots by means of a connecting spring |13. Pawl 69 is provided for stepping ratchet |14 carried on the shaft |16. Attached to a suitably mounted rock shaft |11 is a bell crank |18 having an arm |18 which is urged into engagement with ratchet |14 by means of the spring |8I. Also xed to rock shaft |11 for movement therewith is the print hammer lever |82 carrying at its free extremity the usual printing element |63. Thus, as the main operating slide ||6 moves to the right as viewed in Fig. l pins |66 carried thereby will cause a clockwise pivotal movement of bell crank |64 which thereby operates pawl |69 to step the ratchet |14. At this time arm |19 of the bell crank |18 is cammed outwardly tensioning the spring |8|. As bell crank |64 reaches its extreme clockwise position, arm |19 now moves over a. tooth of the ratchet |14 enabling spring |8| to move the print hammer lever |82 in a counterclockwise direction causing a sharp operation of the printing element |83. Immediately thereafter pawl |1| which has moved away from the tape feeding ratchet |10 engages the neXt tooth of ratchet |10 to thereby step the tape forward one position for the next operation. Ratchet |10 is secured to a shaft |80 which at its other end carries the tape feed wheel |84.

For setting the code drums 90, 10, and 89 to prearranged positions each of the shafts H8, |29, and |39 are provided with dials |86. To prevent tampering with the code drums after they have been set, plate |81 (Fig. 5) is mounted for vertical movement on pins |88. This is accomplished by means of a standard cylinder lock |89 (Fig. 5) which, when operated by a key, moves shaft |9| and eccentric |92 welded thereto in a counterclockwise direction. This lifts the plate |81 upwardly by means of slot |95 engaging pin |90 carried by plate |81, so that it becomes locked in the grooves |93 of discs |94. Clearance, however, is provided so that discs |94 are free to rotate. Discs 94 are formed as integral parts of sleeves |96 which are rotatable on the shafts |18, |29, and |31 and carry respectively code drums 60, 10, and 88. Plate |81 includes bent over and rearwardly extending projections |91 which overliethe sensing levers 13, 82, and 86 and will disengage them from their respective code drum's 11,

8|, and 84 when the plate |81 is moved downward. This permits free access to and withdrawal of the code drums whenever necessary for adjustment or other purposes.

At the front of the housing 32 is mounted a compartment |98 (Figs. 3 and 4) which underlies the type wheel |58 and houses a tape feed wheel |84 and may include a tape guiding means (not 1shown) for tape |99. Means, not shown, will also be provided for feeding inking ribbon |85 in any conventional manner.

A brief rsum of the operation of the type wheel printer will now be given. lKey slide 44 is depressed which through the ve mechanical chains provided inthe present invention results in the setting of the ve individual selector discs i! and the selection of a particular stop pin |08. The key slide 44 now engages universal bar thereby operating bell crank ||2 and moving the main operating slide I6 to the right as viewed in Fig. l. This operates gear segment |49 causing rotation of stop arm |09 until it is stopped by a selected stop pin |06. Main operating slide continues to move to the right, tensioning spring |8| of bell crank |18 and causing operation of print hammer lever |82 with a snapping action. As the main operating slide H5 returns to the left, pawl |1| operates tape feeding ratchet |10 to step tape |99 to its next position. At the same time pawl V|59 assumes a position to engage the next tooth of ratchet |14.

Return movement ofl main operating slide 1| |6 to the left causes pawl 2| to step ratchet ||9 to its next position, and when the notch |24 of disc |23 is presented to 'lug |28.of pawl |21 this' latter pawl will step ratchet |28 to its next position.r Also when notch |32 of disc 3| is presented to lug |33 of pawl |34 this pawl will step ratchet It is understood that various changes andv modifications may be made in the present invention without departing from the spirit and scope thereof.

What is claimed is:

l. In a type wheel printer, atype wheel, a

. plurality of selectable elements for determining operating said printing means after said type the stop position of said type wheel, a mechanical chain for each of said selectable elements including a series of pairs of movable members, mechanical means for variably selecting either one of each pair of movable members for movement, means for operating each of said chains to select said selectable elements, means for causing said type wheel to move to its selected stop position, printing means in operative relation with said type wheel, and means for operating said printing means after said type wheel has been positioned.

2. In a type wheel printer, a type wheel, a plurality of selectableelements for determining the stop position of said typewheel, a mechanical chain for each of said selectable elements vhaving at least two parallelly arranged linkage systems each including variably positionable elements, means to Vary the position of said variably positionable elements, means to operate each of said chains in accordance with the operation of said position varying means to thereby determine the selection of said selectable elements, meansv for causing said type wheel to move to its selected stop position, printing means in operative relation with said type wheel, and means for wheel has been positioned.

3. In a type wheel printer, a type wheel, a plurality of selectable elements for determining the stop position of said type wheel, a mechanical chain for each of said selectable elements having at least two parallelly arranged linkage sys-` tems each including variably positionable elements, key operated means for varying the position of said variably positionable elements, means to operate each of said chains to provide a continuous path of movement through parts of at least two linkage systems of each of said Chains or completely through one linkage system dependent on the operation of said key operated means to thereby control the selection of said selectable elements, means for causing said type wheel to move to its selected stop position, printing means in operative relation with said type wheel, and means for operating said printing means after said type wheel has been positioned.

4. In a printer, a plurality of character selecting elements, a mechanical chain for each of said elements having at least two parallelly arranged linkage systems each including variably positionable elements, means to vary the position of said variably positionable elements, means to operate each of said chains in accordance with the operation of said position Varying means to thereby determine the operation of said character selecting elements, and printing means for printing a character selected by said character selecting elements.

5. In a printer, a plurality of character selecting elements, a mechanical chain for each of said elements having at least two parallelly arranged linkage systems each including variably positionable elements, key operated means for varying the position of said variably positionable elements, means to operate each of said chains to provide a continuous path of movement through parts of at least two linkage systems of each of said chains or completely through one linkage system dependent on the operation of said key operated means to thereby control the selection of said character selecting elements, and printing means for printing a character selected by said character selecting elements.

MARTHA W. C. POTTS, Eecutrirc Under the Last Will and Testament of Louis M. Potts, Deceased.

REFERENCES CITED FOREIGN PATENTS Country Date Italy of 1934 Number