·May 15, 1951 

1 . .. 

II) xx 

"' x x 

- x x 

IQ ~ ~ ~ ~ ti ~ ;: ~ ~~ 

~ ~ 

~ 

-~ ~ I 

~ 

\ 

~ 

" ~ 

"i ~ 

~ 

' 0 ~ 

~ ~· ,. .~ I -~ ' i ~ • ~ 

REF ID:A4161579 

W. F. FRIEDMAN 

FACSIMILE ENCIPHERING SYSTEM 

Filed March 6, 1943 

/ 

2,552,548 

,, 
REF ID:A4161579 

Patented May 15, 1951 2 ·552 54·g 

' ' 

1: 

P:ATENT 

2,ss2;s48-

FAcs1MmE ENCIPHER,ING SYS'EEM 

Williain F.-Frfodlnan, Washington, D. c. 

Applicatfon1Mai'clL6, 1943i'Serfal No:'478~193· · 

5 Claims;. (Cl .. 178-5.l) 

(Granted': under: the'.: act of March 3, 1883, as amended Aprih 30, 1928;: 370· 0: G. 757") 

2 

The invention' described; li.erein-may ·be,manu- Figure 3:15. a· circuit diagram of the· receiver 

factured and used by or for the Government for in'·,block- form. 

governmenta:l purposes; without' the payment'. to Ii1 the one embodiment of my invention which 

me· of: any TOYalty:thereon:~. · has b-een· selected from among others, my device 

The·,subject matter-' of this!invention:is1~a;.'.sys"- fi. is• ·shown as comprising a transmitter section 

tern for· enciphering .facsimiles:: having a motor I driving shaft 2 carrying trans·-

This. invention relates; to means:' for '.Secretly parent. dn1m 3 surrounded by message sheet: 4 

communicating: infoi:mation1 by ·transmitting·· a and alSo carrying transparent.drum.5 surrounded 

facsimilei of the:·messagel'in-.·:a; graphic •form .. of by -control sheet G. Within drums a· and 5:.are 

any sort suchc as' ·a .. writing~ type'-writlng;"pic'- 10 located electric lamps rand a: which serve as ture: photograph·or:.the: like. Secrecy:istobtainect sources of light and which: are energized-from: a 

by· transmitting~ a~:seriescof'. impulses caused· in source of electricity 9'. Opposite lamps. l" and ·a 

part by• the message• to. be: transmitted• and':in so as to receive a beam of· light therefrom and', 

part:byc-a contro1·-in··graphic' .. form1·suefr·as1•any respectrvely, under the control of message·sheet 

writing-; picture2or·random' arrangementJof··ctots 15 4 and .control sheet 6, are located light'-sensi·-

or lines: Stich a .:control does: ·not,·necessarily tive. cells I 0 and 11 which form parts· of ·cirhave; any: intelligibility in' itself. It.aper.ates: ·as cuits including amplifiers 12 and 13 and· relay 

a random· key:: At the·- receiving: rend, ~a'--dupu-.: coils. 14 and 15. These· relays also include• mov- cate of this controLis employed~: This: duplicate able contacts ts: and· 11 bi'ased in. one direction 

control is:moved int synchronism with~thei move- 20 by springs 18'. and 19 and, in the. other direction, 

ments-of~the:control;at:the: transmitting;end.fand by coils 1·4 and· 16, respectively; when these coils 

causes a series:of-impulses·.which·~co·.:operateiwl.th are energized, and engaging one or the· other of 

the impulses received:from.:the1transmitter,!the stationary contacts 20 and 21. Contacts !6, ff, 

interaction between the! two ·series:: of 'i.Iripulses zo· and" 2 f form parts of a circuit,. including a serving to· produce 3; facsimile~· of.' the,'ol'igina'l 25 source- of current 22 and relay coil 23, which, 

message; when energized; attracts movable'contact 24-into 

It is an object; .therefore;. of. my,·invention:.:to engagement with stationary contact 25,. over~ 

provide apparatus·comprising·:a:.transmission:sys= coming the pull of spring 26: Contacts ·24:·and 

tern. including: a;_ transmitter:·sectioni:and-ra:.:re~ 25' control a circuit including. transmitter 2l 

ceiver. section. Each of: said··sections~hasnas.:ia ::fl having' an output element 28, shown as an. anpart thereof, an· electric- circuit includin.g ·the tenna. 

contacts of: ·a'. plurality of: refays'.'interconnected At. the'•place to which it· is desired' to t1;ansin.·such1 a way as to cause-a. plura:lity'.of:linptil:Ses mit the. intelligence, there· is located a receiving 

to. circulate. ill' said· circuit:. In:.the''transmitter systemr having a receiving element, indicated 

section these. impulseS'.Tepresent·.-the ·comoihed ,,,, as an· antenna 29, forming. part of receiver 

effects due-to.the message to;,be-trnnsmitted'.'and 30"'whfoh·is·connected into circuit so as to conto. a control-element. A'.n impulse can•orily;occur trol relay' coil 31. This relay also includes movin this· circuit when both- of'the'•relirys!have •not able contact 32"stressed away from coil 31 by 

moved- their- contacts to the same<'positioi:i;. rn- spring: 33· and co-operatin"g· with stationary conthe receiver section these' 'iinptilses represent •JO tacts 34. Motor 35 drives· shaft 36•carrying'trans:.. 

those caused by -tne orig·triaI·'message:'·sifice •tl'le parent' drum 3l surrounded by second control 

im.pulses due to the· control have oeen"removed sheet 39·, which is a duplicate of conti'ol sheet 

by the use of a duplicate of· the' controNn tfi'e &: Within drum 37' is lbcated electric lamp 39; 

receiver section. energized by a source of efoctdcity 40. OppoFor. a further exposition' of· my.-inventicm"·refer;; 45 site1 famp 39 so as to receive a beam of light 

ence may be had to the annexeil·drawings ·and: therefrom under· the control of second control 

specification at the end· whereof!'the"novell·feat- sheet 38, fa located light-sensitive cell 41 wli.ich 

tures of my invention will be speCificaJly'·poinfod: forms a' part of a cfrcuit including amplifier 42 

out and. claimed. and relay coil 43: This relay also· inclUdes movIn· the drawings:· 50 abfo·contact 44 biased in one· dfrection by sprihg 

Figure 1 is a circuit diagram' of· th1Vtrainsmit" 45·- and, ih· tfie· otl'ier direction: by coil 43, 'wheri 

ter with parts,designated'b:Y blockS--'bearihg'·ap'-' tliis: coil is ener-gized, ·so as ·to-'engage one·'-or 

propriate labels. the ·other of stationar.y contacts 1113. ContactsC34 

Future' 2 ·is. a" tabulation illustratiri:tpthe• iin'- and'46: form<parts.of:a circuit· including:ai source 

pulses.;comprising, the .intelligence• tra;rismittedr 65 of'celectricity.· ·en·- and a; relay~ coil '48;- 'rhis'·-re-" 
REF ID:A4161579 

2,652,548 

3 

lay includes movable contact 49 stressed away 

from coil 48 by spring 50 and co-operating with 

stationary contact 51. Contacts 49 and 51 are parts of a circuit including a source of electricity 

52 and coil 53, which is the operating element 

of a facsimile reproducer of any convenient type. 

The operation of my device is as follows: The 

message and the control sheets are in any graphic 

form such as a writing, printing, drawing, photograph or the like. They may be said to consist 

of pluralities of spots or elemental parts each of 

which is either black or white depending upon 

the part of the message which it forms. Relative movement is provided between lamp l and 

message sheet 4, between lamp 8 and control sheet 

6, and between lamp 39 and second control sheet 

38 in any convenient manner heretofore used in 

the art of facsimile transmission. This causes the beam of light emitted by each lamp to scan every spat or element of the message or control 

associated with it. In the transmitter this scan- ning thus produces a series of impulses in the 

amplifying circuits through the action of the light 

sensitive cells ID and I I. For convenience of de ... scription, these impulses can be said to be produced by black spots in the message or control. 

Thus coils 14 and 15 are energized every time an impulse occurs in the amplifying circuit asso- ciated therewith. The action of the relays con- trolled by these coils produces in the circuit asso- ciated with them a series of impulses distributed 

in time as shown in Figure 2 of the drawings in 

which the term "X" represents an impulse. This 

figure shows the four possible cases. Thus it will 

be seen in column 1 that energizing coil 14 by 

message sheet 4 without energizing coil 15 by con- trol sheet 6 causes an impulse in th8 circuit con- taining coil 23 and labeled "Result" in Figure 2. 

This energizes coil 23 and causes transmitter 27 

to emit an impulse. As seen in column 2, when 

both coils 14 and 15 are energized no impulse 

appears in the circuit containing coil 23. As seen in column 3, energizing coil 15 but not energizing 

coil 14 causes an impulse in the circuit containing 

coil 23. Column 4 shows that when no impulse is 

present in either amplifier 12 or 13 and, conse~ 

quently, neither coil I 4 nor 15 is energized, no impulse appears in the circuit containing coil 23. 

To put it another way, an impulse only appears 

in coil 23 and, therefore, an impulse is only sent 

out from transmitter 21, when coils !4 and 15·are 

not in the same condition, i. e., are not simultaneously energized or de-energized. This is due 

to the fact that simultaneous energization or deenergization of coils 14 and 15 causes movable 

contacts I 6 and 17 to engage stationary contacts 

20 and 21, respectively, which are connected to 

the same side or polarity of source 22. 

The series of impulses emitted by the output 

element 28 of transmitter 21 is received by the 

input element 29 of receiver 30. Each impulse so received energizes coil 31. Motor 35 produces 

relative movement between second control sheet 

38 and light 39 so that control sheet 38 is scanned 

in synchronism with control sheet 6. Since second control sheet 38 is a duplicate of control sheet 

6, coil 43 is energized in synchronism with the 

energizations of coil 15. Referring again to Fig- ure 2, the line labeled "Result" represents the 

impulses which pass through receiver 30 and energize coil 31, while the line labeled "Control" represents the simultaneous impulses caused by control sheet 38 and which energize coil 43. Figure ·2, 

column I, shows that when there is an impulse 

in coil 31 and none in coil 43, an impulse is pro., 

4 

duced in coil 48, which is represented in Figure 2 

by the line labeled "Message." Following 

through the other columns of Figure 2 shows 

that when coils 31 and 43 are simultaneously 

5 energized or de-energized, no impulse appears in 

coil 48. Likewise, while either coil 31 or 43 is 

energized when the other is de-energized, coil 48 

is energized. ·The energization of coil 48 causes coil 53 to be energized and coil 53 operates a 10 stylus or other marking mechanism and thus 

message sheet 4 is reproduced. 

·-rt: will .be .understood that, whereas the foregoing description calls for the transmission of a signal when one only of the coils 14 and 15 is ener- 16 ·gized; the apparatus will function just as well and 

achieve just as great privacy if rearranged 

slightly, as by giving an opposite bias, a normal 

closed condition, to switch 24-25. In such case, 

.c}f course, a signal will be transmitted whenever 

20 coils 14-15 are in the same condition instead of 

when they are in different conditions. 

I claim: 

1. ·Means for secretly transmitting graphic information, said means comprising, a message in 

25 graphic form which it is desired to transmit, a scanner arranged to scan and reproduce said 

message as a series of electric impulses of varying .intensity, a screen having varying portions, a second scanner arranged to scan and reproduce 

30 the variations of said screen as a second series of 

electric impulses of varying intensity, a relay 

connected under the control of said scanner and 

arranged to be moved by each of said impulses 

to one of two positions, a second relay connected 

;;;. under the control of said second scanner· and 

arranged to be moved by each of said second impulses to one of two positions, an electric circuit 

including parts of· said relays and adapted to be 

closed only when there is instantaneously an im411 pulse in· either series but not in the other, a 

transmitter connected under the control of said 

electric circuit so as to emit impulses whenever 

said circuit is closed, a receiver arranged to re- ceive the impulses emitted by said transmitter 

45 and having an output comprising a third series 

of electrical impulses of varying intensity, a second screen duplicating said first mentioned 

screen, a third scanner arranged to scan synchronously ·with the scanning of said second scanner 

60 and·reproduce the variations of said second scre·en as a fourth series of electric impulses of varying 

intensity, an electromechanical interlock con- nected under the control of said third and of said 

fourth series of impulses and arranged to be ener- 65 gi.,zed whenever an impulse occurs in one of said 

third and fourth series and no impulse occurs simultaneously in the other of said third and 

fourth series, and a recorder connected under the 

control of said interlock and arranged to operate 

60 whenever said interlock is energized and to 

thereby reproduce said message. 

2. Means for-secretly transmitting graphic information, said means comprising, a message in 

graphic form which it is desired to transmit, a 

65 scanner arranged to scan and reproduce said mes- sage as a series of electric impulses of varying 

intensity, a screen having varying portions, a 

second .scanner arranged to scan and reproduce 

the variations of said screen as a second series of 

70 electric impulses of varying intensity, an electrom~_chanical_interlock connected under the control 

of ,bqtJ:i: of said series of impulses and arranged 

to be energized whenever an impulse occurs in 

one of said series and does not occur simultane76 ously ·in. ·the other of said series, a transmitter. 
REF ID:A4161579 

2,552,548 

5 

connected under the control of said interlock so as to emit impulses whenever said interlock is 

energized, a receiver arranged to receive the impulses emitted by said transmitter and having 

an output comprising a third series of electrical 5 

impulses of varying intensity, a second screen duplicating said first mentioned screen, a third 

scanner arranged to scan synchronously with the 

scanning of said second scanner and: reproduce 

the variations of said second screen as a fourth 10 

series of electric impulses of varying intensity, a 

second electro-mechanical interlock connected 

under the control of said third and of ~aid fourth 

series of impulses and arranged to be energized 

whenever an impulse occurs in one of1 said third 15 

and fourth series and no impulse occurs simultaneously in the other of said third and fourth 

series, and a recorder connected under the control 

of said second interlock and arranged 'to operate 

whenever said second interlock is energized and 20 

to thereby reproduce said message. 

3. Means for secretly transmitting graphic information, said means comprising, a message in 

graphic form which it is desired to transmit, a 

scanner arranged to scan and reproduce said 25 

message as a series of electric impulses I of varying 

intensity, a screen having varying portions, a 

second scanner arranged to scan andl reproduce 

the variations of said screen as a se~ond series 

of electric impulses of varying intensity, a relay 30 

connected under the control of said sdanner and 

arranged to be moved by each of said impulses 

to one of two positions, a second relay1 connected 

under the control of said second scanner and ar- ranged to be moved by each of said second im- 35 

pulses to one of two positions, an electric circuit 

including parts of said relays and adapted to be 

closed only when there is instantaneously an impulse in either series but not in the other, a 

transmitter connected under the control of said 40 

electric circuit so as to emit impulses whenever 

said circuit is closed, a receiver arranged to re- ceive the impulses emitted by said transmitter 

and having an output comprising a third series of 

electrical impulses of varying intensity, a second 45 

screen duplicating said first mentioned screen, a third scanner arranged to scan syn'chronously 

with the scanning of said second scanner and 

reproduce the variations of said second screen 

6 

transmitting graphic information, means for 

scanning a message to be transmitted to derive 

therefrom an electric signal irregularly assuming a succession of values responsive to the photographic density of the message at the point of 

scanning, means for substantially simultaneously 

scanning a camouflage message to derive a second 

electric signal irregularly assuming a succession 

of values depending upon the photographic density of the camouflage message at the point of 

scanning the second said electric signal being nonsynchronous with the first with respect to the 

variations therein, a switch having two circuitclosing positions, means for causing said switch 

to assume one of its circuit-closing conditions 

when said first-mentioned electric signal assumes 

one value and the other of its circuit-closing conditions when the said first-mentioned signal as- sumes another of its values, a second switch having two circuit-closing conditions, and means for 

controlling said switch responsive to said second 

electric signal, a third switch, a· control circuit 

for said third switch said circuit serving to close 

said switch when the first-mentioned two switches 

are in predetermined circuit-closing positions 

only, and means for transmitting a signal when 

said third switch is in closed condition. 

5. Means for secretly transmitting graphic information comprising a device for scanning a 

message to be transmitted and reproducing said 

message as a series Of electric impulses of varying 

intensity, a second device for scanning a camou- flage message and reproducing the same as a 

series of electric impulses of varying intensity the 

impulses of said second series being non-synchro- nous with the impuls_es of the said first series, 

a relay connected under the control of said first 

device and arranged to be moved by each of said 

impulses to one of two· positions, a second relay 

connected under the control of said second device 

and arranged to be moved by each of the impulses of said second series of said impulses to 

one of two positions, an electric circuit including 

said relays adapted to be closed only when predetermined combinations of closed positions in 

said relays occur· simultaneously, and a transmitter connected under the control of said electric 

circuit so as to emit impulses only whenever said 

circuit is closed. 

WILLIAM F. FRIEDMAN. 

REFERENCES CITED 

The following references are of record in the 

file of this patent: 

as a fourth series of electric impulses i of varying 50 

intensity, a third relay connected under the con- trol of said third scranner and arranged to be 

moved by each Of said impulses Of said fourth 

series to one of two positions, a fourth relay 

connected under the control of said receiver and 

arranged to be moved by e_ach of said impulses 55 UNITED STATES PATENTS 

of said third series to one of two positions, an 

electric circuit including parts of said relays and 

adapted to be closed only when there is instantaneously an impulse in either said third or said 60 fourth series but not in the other, and a recorder 

connected under the control of said circuit and 

arranged to be energized whenever said circuit 

is closed to record the original message. 

4. In an apparatus of the nature described for 65 

Number 

1,310,719 

1,312,574 

1,657,366 

1,763,358 

1,848,839 

1,868,967 

2,300,664 

Name Date 

Vernam ---------'--- July 22, 1919 

Pierce ------------- Aug. 12, 1919 

Belin -------------- Jan. 24, 1928 

Jenkins ___________ June 10, 1930 

Ranger ------------- Mar. 8, 1932 

Cartier ------------ July 26, 1932 

Francis ------------- Nov. 3, 1942 
-· j 

'; 

Ii ! . 

REF ID :·A4161579 

I 

I 

I 

I 

' i 

! 

• 

.:..,,., 
Dec. 1 t, 1928 

D 

A 

REF-ID:A4161579 

W. F: FRIEDMAN 

METHOD.OF.ELECTRICAL SIGNALING 

Filed July lO. l922 

F' 

1,694,874 

t vne.d.. Tio Moc:lulctting 

frequencies 

Ba.nd, C re~­

pect1vely. 

_ .... ______ __,'f"o+---- - --- ---- - ------1-"'Re_c_e-1v-e-rs_t_u_n_e_d.. .... t•o--

F11'. 1. or Record- ca.rrier wa.~ freque.ne1esi.. 

D tng De.vice, R~c.en.1e.r!:i tvne.d... to mod..- Re.ce1vers tvned. to mod.via..- la.t. ~ G. d,. H _{l_-t..!,n!l.£.'=.°~e..!!.c!. Oa..nd Ercs u 1ng r-eqvenc1e.s. ca..n r-e.sp. 

-~=-=-=~=..,,.,-:-:t!=-=.,..,~~ , ----

D 

Q 

• 

.F 

I 

I 

I 

I 

I 

I 

~ R' 

Fig.4. Inventor 

Wi\lin.m F. Friedman . 
' ' 

REF ID:A4161579 

Patented Dec. 11, 1928. 1,6~4,874 

UNITED STATES .. PATENT OFFICE. 

WILLIAM F. FRIEDMAN, OF WASHINGTON, DISTRICT, OF COLUMBIA. 

METHOD OF ELECTRICAL SIGNALING._ 

Application filed· July 10, 1922. Serial No. 573,981. 

(GRANTED U~ER THE ACT OF MARCH 3, 1883, AS A_MENDED "'1'RIL 30, 1928;' 370 0. <!· 757.) 

This invention relates in general to elec- waves are first separated by tuning to the 

trical signaling systems and more particu- -frequencies of the carrier waves and then 

larly to systems for the simultaneous trans- tuning again to the modufating frequencies. _55 

mission_ of a plurality of messages through Figures 3 and 4 are the same as Figures 

-5 one and the same channel, and has for its 1 and 2, respectively, .except that the arobject the provision of a new and more rangements in Figures 3 and 4 are adapted 

simple system of cil'.cuits for achieving th_is for radio transmission instead of line trans- .-. , ·end. _ · mission. · 60 

A further object of the invention is to Having more particular reference to the 

JO effect a reduction of the length of time nee- drawings, and m connection with which 

essary to transmit and receive each of a li'ke characters of reference designate simiplurality of messages by the heretofore prev- lar parts throughout, iri Figure 1, A is a ~tlent systems of multiplex printing teleg- .source of high frequency oscillations of con- 65 

raphy, and thus i_ncrease the capacity of a stant frequency, designated hereafter as the 

U single channel. _ carrier wave; · B and C are arrangements - ·A further object is-to effect an increase in for modulating the carrier wave, each difthe number of telegraph messages which ferently modulating the carrier wave A; 

can be transmitted over a single channel by D and E are keys which respectively con- 10 

the heretofore prevalent systems of multi- trol the modulation elements B and C. 

20 plex telegraphy. - _ - _ · · ';fh~s~ keys may be· operated manually by 

A further object is_ to· achieve a system of md1v1dual operators employing the Morse 

multiplex radio telegraphy by the use of a code signals but as shown in the figure they 

single wave instead of a plurality of waves are here illustrated as operatively connected· 75 -

of different frequencies.·. to I, which is a sending keyboard or an auto25 The fundamental p~inciple of my invert- matic tape-controlled transmitter, both of 

tion is the differential modulation of a, single. well known form. F and F' constitute the 

carrier· wave· and the selective isolation of line which the carrier wave traverses. B' 

the several modulating frequencies -at the· and C' are selectively .. tuned circuits respon- 80 · 

receiving end, each so isolated modulating sive to the carrier wave A; D' and E' rep,-

30 wave affecting a different independent cir- resent circuits selectively tuned to respond 

cuit. individually to the respective modulating 

In order that the invention and its mode frequencies; G and H are relays which niay 

·of application may be readily understood be of well known forms, and are operable 80 

by persons skilled in the art, I .ha.Ve,. in the by the currents passed by D' and E' respec35 accompanying illustrative drawings, and in -tively, but' they may be any other form of 

the detailed following description based device suitable .for making the currents of 

thereon, set forth aQ embodiment ·of the the isolated frequencies perceptible to the _ same. eye or ear, or for recording these cm:rents 00 

F.igure 1 is a diagrammatic sketch :.of one in a suitable manner. The figure; however, 

40 form of arrangement of circuits whereby a shows G and H to be relays operatively conhigh frequency current carrier wav_e is nected to J, a printing or recording device 

modulated by several modulators of differ- of any of the well known forms. 

ent character, the modulated currier wave Let us suppose that A impresses upon the 95 

impressed upon a line and the several modu- line F-F'· a carrier w_ave of 50000 cycles 

43 lating frequencies selectively sepa·rated at the. per second, that B modulates the carrier 

other end of the line. . wave by 1000 cycles per second and that C _ Figpre 2 is a diagrammatic sketch of one modulates the carrier wave by 2000 cycles 

form of ·arrangement of circuits whereby per second. Therefore a carrier wave modu- 100 

a plurality of high frequency carrier waves lated in one instance to a 49000-51000 cycle 50 are each modulated by several m<;>dulators wave, and in the other instanc~ to a 48000-

of .different characters, and at the other . 52000 cycle wave is impressed upon the line. 

end · of the line thes.e modulated carrier At the receiving end of the line B' and C' 
REF ID :A4161579. 

2 1,694,874 

are circuits tuned to the carrier frequency ing telegraph systems. which emfloy code 

of 50,000 cycles, and the carrier wave cur- signals consisting of a plurality o elements 

rent will divide, part, passing to one cir- or units affecting a plurality·of relays assocuit, B', and a part passing to the other cir-· ciated with a printing or a recording mech5 cuit, C'. But D' and· E' are arranged to anism. It may be desirable to discuss brief- 70 

respond to different modulating frequencies, ly this aspect -of the invention. 

that is, one will be acted upon only by the In the heretofore prevalent forms of print1000 cycle modulating frequency, and the ing telegraph systeμis, the automatic opera- . other will be acted upon only by the 2000 tions concerned in causing a printing. mech10 cycle modulating frequency. In that way anism to .function at a distance are con- 75 

the different modulating frequencies are trolled by groups of equal potential, direct 

separated. Hence relays G and H will re- current electrical impulses which pass over 

spond selectively to the modulating fre- . one and tl).e ~ame lin~, and actuate a set. of 

quencies of B and C. relays, eadh ·impulse ill the group effectmg 

l!i The tuning of the receivers B' and C' to the operation. of _a particular relay,_ by a 80 

a modulated wave which covers ·a narrow method described below. . These relays acband of frequencies as in the preceding ex- tuate magnets which set up combinations of . ample, 49000 to 51000 cycles or 48000. to. selecting discs in a printing mechanism, and 

50000 cycles, may be accomplished by the· each character of•the message is determined 

20 well known methods in the art, which may by a different ·combination or arrangement 85 

be by the use of band filters, or any other · of these selecting discs. Usually there ai·e 

suitable circuit arrangements. 32 such combinations, 26 for the ordinary · In the same way a plurality of carrier letters and 6 others concerned in certain , waves of different· frequencies may be em- functions of the printer; such as carriage 

25 ployed, each.carrier wave separately mod.u- return, figure shift; and so on. The signals 00 

lated by several modulations of different for message characters as . commonly . used 

characters, and at t_he receiving end the dif- in these systems constitute what is usually 

ferent frequency carrier waves are first sepa- termed a five-un~t- code, that is, it consists 

rated· by suitable tuning and by further tun- of permutations of two elements taken five 

30 ing the individual modulating frequencies at a time. In one system .of operntion these DIS 

on ·each carrier wave may be isolated. Thus two elements .may be positive. an.d negative 

a multiplex system of extremely wide range potentials; in which case the· code signal for 

is made possible. This. is shown diagram- a character consists of the , distribution · matically in Figur~ 2, where A represents through time of fiv.e elements composed of . 35 one unit of carrier wave current of onr. fre- positive and negative impulses .. In another 100 

quency from source C, with its associated system of operation the two elements ·may · modulating frequencies D and E, and B consist of a time-interval when .an impulse 

represents another unit of carrier wave cur- is. sent, and a tim,e-in~rval when no impulse 

rent of another frequency from source F, is sent, this being the' m'ethod of closed and 

40 with its associated modulating frequencies, open cii·cuit operation. The code signal for 105 

G and H. A' represents a system of circuits the letter "A" for example, is"-- - - -," 

comprising circuits. C' and C" selectively "foch in the positive and negative system 

tuned Jo tbe frequency of the carrier wave of operation means that the first and second 

C, and circuits D' and E', selectively tuned units of the signal are positive impulses, 

45 to the ·modulati~g frequencies D and E, the third, fourth, and fifth, are negative 110 

which are produced at A, and I 1

· .J, are re- impulses. In tl~e open and .closed circ.uit 

la rs actuated by circuits D', E', respectively. system of operation, this code signal means 

B represents a system of circuits comprising that only the first two time units are occucircuits F' and F", selectively tuned to the pied by the passage of current, the last 

50 frequency of the carrier wave, F, and cir~ three, unoccupied. The permut:ations of 115 

cuits G' and H', selectively tuned to· the . transmitted impulses are governed by a set 

modulating frequencies, G and H, whiCh · of make and break keys operated at the 

are produced at B, and K, L are relays ac- transmitting. end malrnally, by means of a 

tuated by circuits G', H", respectively. :M, sending keyboard similar in form to the 

55 N, O, and P are the keys controlling the· ordinary typewriter keyboard, or automati- 120 

modulating circuits at A and B, and Q, Q' · cally by means of a transmitter controlled 

is the line. , · · · · . by a perforated tape. · 

' It is obvious also that transmitting sets In .order that a plurality of relays shall 

can be placed at both ends of the· line, and . be controlled by impulses of equal poteneo their corresponding receiving sets at both tial, and all coming over the same line, or 125 

ends of the line, so that multiplex operation through the same channel, and that the per- . 

is possible. For such operation a plurality mutation Of relavs actuated at the distant 

of single period generators or a sirigle multi- end shall correspond to the permutation of 

period generator can be employed. . This . depressed keys. at the sending end, in the 

66 arrangement is especially adapted for print- :heretofore prevalent systems, ~nnection is iao . 

-. 
·~ 

REF ·ID:A4161579 

1,094,874 3 

established between each key at· the sending multaneously, and at the receiving end are 

end and its corresponding relay at the re- properly isolated by five selectively tuned 

ceiving end at a different instant, and. the circuits. ' · . several connections necessarv to transmit the There is, of course, nothing novel in modua code signal for each message character are lating a carrier wave either telephonically ;o 

made in a definite, fixed sequence. Thus, for or telegraphically. The novelty of my in-. 

example, in the case of five relay!? respec- vention consists in modulating a single cartively controlled by five make and break rier wave telegraphically by severa.l diskeys, the time necessary to send the signals tinct modulating frequencies, and isolating 

10 for one character is divided up into five each modulating frequency individually. In. 75 

equal intervals;' during the first interval telephonic modulation a relatively wide band 

connection is· established between key 1 at of modulating frequencies is imposed upon 

the sending end and its corresponding relay the carrier wave, and this band of heter1 at. the receiving end; during the second ogeneous side frequencies is faithfully re11> interval, connection is established between· produced by the telephone receiver at so . ~ey 2 at the sending en? .and its correspond- the receiving end. The human ear hears 

mg relay 2 at the rece1vmg end, and so on. all of these heterogeneous side frequenThe method of effecting such a. correspond- cies simultaneously, but is able to disence in action by transmitting similar im- tinguish them and hear them separately if 

20 pulses through one and· the same channel an· effort is made. For example, when or 0 s;:; 

involves the use of a distributor and vari- chestral music is being tr:,msmitted by radio 

ous other apparatus ~n~luded und~r t~e gen- telephone, the radio au~ience hears the ~~­

eral term "synchromzmg mechamsm.' semble effect but there is absolutely no difThe principal of the synchronizing dis- ficulty in distinguishing the music produced 

25 tributor is this: two similar rings, one, on by a violin from that produced by a cornet. oo 

the. sending face of a distributor at t_he Both sounds are being transmitted on one· 

transmitting station, the other on the re- and the same vehicle or carrier wave, but 

ceiving face of. an identical distributor at the modulating frequency of the sound vithe receiving station, are each divided into brations of th(;l violin is different from that 

80 five equal segments. A pair of rotating of the cornet. While in the illustration giv- o.; 

·brushes _on these _distributors are connected en abov~ th~ separation of the m?dulating 

to the lme, and when these brushes revolve frequencies 1s effected by the ear, m the arthey sweep 'over and make contact with the riu:igement of this invention the separation 

segments of their· respective rings. The of the modulating frequencies is accom81i brushes at the two ends of the line start from plished by mechanical or electrical tuning 100 

the same relative position. and sweep over devices; . . . the contact segments with the same uniform In Figure 3 the ·arrangements of circuits 

angular velocity, thus connecting the first is identical with that. shown in Figure 1, 

segment of the ring of the sending distribu- but instead_of having a line upon which the 

40 tor with the first segment of the ring of the modulated carrier waves are impressed, a lO.:; 

receiving distributor once per revolution of transmitting antenna, f, with its ground I, 

the brushes. Likewise the second, third, serves to radiate the modulated waves into 

fourth, ·and fifth segments of the sending space, and a receiving antenna F', with its 

distributor are connected once per rernlution ground I', serves to receive the waves radi46 of the brushes with the corresponding seg- ated by F. . · . 110 

ments of tlie· receiving distributor, the in- In Figure .4, the arrangement of c~rcu~ts 

terval ·of each connection being the time of is identical ~ith ·that shown in Figure 2, 

.one-fifth of a revolution of the ·rotating but instead of having a line upon which the . btushes. Thus, each message character is modulated carrier, waves are impressed, a 

50' transmitted as .a combination of fiye sepa- transmitting antenna, Q,, with its ground R, 115 

rate or discrete impulses distributed equally serves to radiate the modulated waves into 

and in a -definite sequence through an inter- space, and a receiving antenna, Q,', with its 

';al of time, and for each revolution of the . ground, R', serves to receive the waves rabrushcs, the code impulse combinations for 'diated by Q,. . 65 one and only one ch\lracter or letter are It is obvious that the arrangements shown 120 

· transmitted and received. The synchro~iza- . in Figure 1 for controlling the O,Peration ·of 

tion of the two distributors so that the re- the keys governing the modulatmg circuits 

spective brushes re~olv~ with exactly the an? !or controllin~ the oper~tion of the 

same ·angular velocity is a very complex prmtmg or recordmg mechamsm, when a 

eo feature of these :printmg telegraph systems, system of printing telegraph is employe~, 125 

and acts as a linuting factor upon the speed also app!y to Figures 2, 3, an~ 4. But it ~ 

of operation. In my system no such s~- also obvious that the mod~la~1~g ke!.s may 

chronization is necesMry, for all of the sig- be operated manually by md1v1dual ope,ranals comprising the combination of impulses tors, a,s stated before, and at the rece1v1ng - 05 for a single· character are transmitted si- end, instead of having. relays, several aper- 131 
' 

REF ID:A4161579 

4 l,694,874 

at.or8 may receive the messages transmitted 

in ordinary Morse characters by using telephone receivers. · . . · It is obvious that radio-frequency oscil5 lations must be employed for radio communication by. the systems illustrated in the · last two figures.. , While I have not indicated in the figures 

any particulars regarding the means to be 

IO employed in producing the carrier wave or 

the manner of modulating the carrier wave, . or the manner in which the modulated carrier waves are impressed on the line or radi-. 

ated into space, it is to be understood that 

15 any of the means and -methods now well 

known in the art may be employed. Nor 

have I. indicated any details with respect to· 

the exact means to be used in receiving the 

modulated carrier waves, selectively sepa20 rating the modulating frequencies, and causing them to affect selectively tuned relays 

or 'recording devices, . for here also · the 

means and methods now well known in the · art apply to this invention. · :d What I claim as niy invention is the following: 

1. In a printil!g telegraph system, a source 

of high frequency electrical oscillations constituting a carrier wave, a set of modulators 

30 of different modulating frequencies which 

can be impressed upon said carrier wave, each 

of said modulators being associated with a 

make and break key which determines 

whether the modulating .frequency con35 trolled thereby will or will not be impressed 

upon the said carrier wave, said keys together comprising a single set 'of keys. acting 

as a single unit associated with a ke,yboard 

mechanism, said keyboard mechanism being 

40" so constituted as to control said set of keys 

permutatively as a unit acc·ording to a plural-unit code suitable for the representation 

of message characters, means for transmitting the permutatively modulated carrier 

45 wave representing the message characters, a 

receiving station, means at sai<;l receiving ____ -statioi;t for detecting said ~ransmitted per- . mutatively modulated carrier wave, means 

for detecting the presence of and for iso" 

50 lating each modulating frequency of said 

permutatively mod~a.ted carrier wave, said 

latter means compr1smg it set of resonant cir~uits appropri,ate.for the purpose, each of 

said resonant circuits being associated with . and adapted to control a relay ,which is op- 55 

erative when the modulating frequency to 

which the respective-resonant circuit is re- . sponsive is p~esent, and is inoperat~ve ·wh~nthe . modulatmg frequency to· which said 

resonant circuits is responsive is not present, oo 

a plurality of relays acting_ as a single unit 

associated with a printing mechanism, said 

printing mechanism being controlled as a 

unit by the joint and permutative action of 

said set of relays in such a manner as t'l · 65 

print the message characters represented by. 

the permutatively modulated transmitted 

and received carrier wave. 

2. In a printing telegraph system comprising a source of high frequency electrical os- 70 

cillations constituting &• carrier wave, a set 

of modulators of different modulating frequencies which can be impressed in a 

permutative manner representing message 

characters in a plural-unit code upon the 75 

said carrier wave by means of a. keyboard 

mechanism controlling a set of keys, governing the action of said set of modulators, a 

receiver capable of receiving the permutatively modulated carrier wave representing 80 

message characters, a set of ·resonant cir- - cuits, each- of said resonant circuits ·being 

responsive to one individual and only one of 

said modulating frequencies, a set of 'relays 

,controlled as a .unit permutatively by the 85 

said set of resonant circuits, and a printing 

mechanism controlled by the said set of relays -and suitable for printing the received 

message characters, the method of permuta~ively and simultaneously impressing the 90 

said modulating frequencies upon the said 

carrier wave, transmitting and subsequent 

receiving and 'detecting the said permuta.-

tively modulated carrier wave, detecting and 

isola.ting the s!lid. modulating freqμencies, 95 

causmg the said ISolated mo<:lulatmg frequencies t.o control the operation of a set-of · ~ -r 

rel~ys permutatively according t.o the pluralumt code representing the message characters tra~smitted, .the said set of relays acting 100 

as a umt to control the action. of a printing 

mechanism suitable for printing the message 

characters. 

In testimony whereof I affix my signature. 

WILLIAM F. FRIEDMAN. 

; '.~ 

'i 

I: 
1\ 

I 

I 

j 

I 

" 

REF ID:A4161579 

Nov. 10, 1953 

filed Aug. 11, 1949 

J. D. ·DURKEE 

PRINTING TELEGRAPH SYSTEM 

4/-------...----. 

40 F'/iEQ.. A 

r--..:::...3.~'Cj=-=-,......::::~~r~~f..-'1ff:,::::==-tFREQ.8 r. FREQ. C 

A 

B 

c 

0 

47a. 

+ 

..;-

r/?E(}. 0 

rREcQ.. £ 

2,658,942 

3 Sheets-Sheet l 

+ + 

.... 
REF ID:A4161579 

Nov. 10, 1953 

filed Aug. ll. 1949 

J. D. DURKEE 

PRINTING TELEGRAPH SYSTEM 

1-----tj1I•·· .____ __ _____. 

2,658,942 

3 Sheets-Sheet 2 

._____,__, ~ ~ 

~~--+-±Ill 
TUNED 

REED 1 &a 

RELAYS; 

/loo .,,/oA 

.... 

.... 

(II 

(I) 

::r 

<D 

<D 

r+ 

~ :::r 

<D 

<D 

r+ 
REF ID:A4161579 

Patented Nov. 10, 1953 2 658 942 

' ' 

UNITED STATES PATENT OFFICE 

2,658,942 

PRINTING TELEGRAPH SYSTEM 

James D. Durkee, Fairlington, Va., assignor, by 

direct and ·mesne assignments, to Dualex Corporation, a corporation of Delaware 

Application August 11, 1949, Serial No. 109,648 

1 

12 C~aims. (Cl. 178-23) 

2 

My invention relates broadly to communication 

systems and more particularly to an improved 

system of printing telegraphy. : 

One of the objects of my invention is to,. provide an improved printing telegraph system particularly adapted for radio communication in 

which conditions of fading, interference,1 and 

static offer minimum detrimental effects , upon 

the printing telegraph apparatus. 

Another object of my invention is to provide a system of printing telegraphy operative a.t relatively high speed and with accuracy iJ.1 the transmiss~·on of printed communications. ! 

·Another object of my invention is to provide a construction of Improved printing telegraph system which involves a minimum of mechanical 

equipment, eliminating necessity for precise; synchronism between transmitting and receiving stations. · . . 

A still further object of my invention is to 

provide a construction of printing telegraph 

transmitter and receiver embodying selective 

electrical circuits with a minimum of mechanical 

equipment for effecting high speed printing telegrap~1_ operations. ; 

Still another object of my invention is to provide a printing telegraph system in which~ permutations and combinations of simultaneously 

applied coded signal impulses are established 

and Impressed upon a vibrating reed con~erter 

including reeds resona:n,t to the individual frequencies of the coded ·signaI-impulses with means for deriving from the conv·erter system direct cur- rent pulses for controlling the selective operation 

of the printing telegraph apparatus. · ·Still another object of my invention is to provide a ·printing telegraph system including a prearranged matrix of electrical circuits individual 

to the characters to be printed and selectively 

operative under control of simultaneously applied 

coded signal impulses for controlling the printing 

telegraph mechanism. 

Still .another object of my invention is to provide a compact construction and arrangement of 

stepping relay, a printing telegraph.mechanism 

controlled thereby, a matrix of electrical circuits 

for controlling the stepping relay, and. a conversion system for operating the said matrix relative to simultaneously applied coded signal impulses for controlling the pr:inting telegraph 

mechanism. ' 

· Still another object of my invention is to provide improved. lightweight printing telegi-aph 

transmitting and receiving apparatus which may 

be used interchangeably in circuits now employing standard printing telegraph apparatus utilizing the international teletype code. 

Other and further objects of my invention re- side in a construction and arrangement of step-

:; by-step relay system for printing telegraph circuits as set forth more fully in the specification 

hereinafter following by reference to the accom- panying drawings, in which: 

Figure 1 schematically shows the transmission 

ifl system of my invention; Fig. 2 is a diagrammatic 

view of· the transmission system illustrated in 

Fig. 1; Fig. 3 diagrammatically shows the receiving system of my invention; Fig. 4 is a diagrammatic illustration of the conversion system, the 

Ui electrical matrix, the step-by-step relay, and the 

control mechanism, associated therewith for operating the printing telegraph equipment; and 

Fig. 5 is a schematic view illustrating the manner of shifting the printing telegraph apparatus from 

20 "Figures" to "Letters" position in the course of 

operation of the printing telegraph apparatus. 

The application of automatic and mechanical 

signalling systems to radio communication has 

been, in the past, limited to circuits, on which 

2.'i there is relatively little or no interference, fading 

or static. These systems have also been limited 

in speed of operation and dependability. Since 

circuits possessing these characteristics are seldom encountered, particularly in the aviation, 

;:;o maritime· and land mobile services, the use of 

manual radio ·operators for radio telephone and 

telegraph communications has been ·necessary in 

the past. · · 

The requirement for increased speed of opera- .,., tions, particulai:ly in the aviation services, has 

created communication demands, ·which can rio 

longer be met by manual operations. Also, the 

large growth of communications activities in general has placed a load ·on the presently available 

40 frequencies which exceeds the capabilities of 

these frequencies where manual methods of operation must be depended upon. 

My invention is directed to a signalling system 

which, due to its ability to operate rapidly and 

45 accurately, eyen in the ·presence of. fading and 

interference, will .satisfy ~he_ demands. for .a high 

speed· automatic. communication system ·for all 

types of radio and wire communications. 

Basically, my method of transferi"ing intelli50 gence from the tfansmittiD.g point to tlie receiv-. 

Ing point is by permutations or combinations of° one or ~ore au4io frequen~ies;m aicordance'w!th 

a pre-~rranged code, -aIJ.d ;1mu1taneously appiy-· 

i?~ ~~ese.J?.ermμt~tfop,s ot cop1bina_tions ~o a wire 

55 circuit· or as ·modulation· to a radio frequ·ency 
REF ID:A4161579 

2,658,942 

3 4 

transmitter. The radio frequency wave containing the coded audio frequency permutation or combination is received by a radio frequency re- ceiver which demodulates it into its audio frequency components and delivers them to the field :; 

coils of a series of tuned reeds or resonant re- lays as audio frequency impulses. These resonant 

relays, which are individually resonant with one 

all printing operations as well as providing com- plete flexibility of transference to any position. 

Description of transmitting apparatus 

The operation of the system of my invention as a printing telegraph device may be understood 

by reference to Fig. 1 in which a keyboard 35 

is provided consisting of a group of letter, figure 

of and functional depressible pivotally mounted keys the audio frequencies contained in the permutation or combination, begin vibrating at the frequency to which they are resonant. When the 

vibrations of the individual resonant relays reach 

full amplitude, an impulse of direct current is applied to a relay or gas triode which stores the 

impulse, electromagnetically, until a mechanism 

for translating the code permutation or combination into printed characters is actuated. 

While I have referred to the use of tuned reeds 

in the mechanism of my invention, I desire that 

it be understood that I may replace the tuned 

reeds by electrical filters, particularly at the high- er frequencies for accomplishing a similar purpose. 

Since the vibration of the tuned reeds of the 

resonant relays are affected primarily by the 

resonance of the impulses with the natural period 

of the reeds rather than by the amount of power 

in each impulse, the action of the reeds is not 

greatly affected by fading signals and, since impulses which are not resonant with the reeds, re- gardless of power, will not cause the reeds to 

vibrate at full amplitude, no direct current is 

transferred to the latching relay or gas tube, and 

thus no code permutation or combination is presented to the translating mechanism. Therefore, the system is substantially unaffected by 

interfering signals or static. 

Conversely, if the audio frequency oscillations are continuously applied and the reeds maintained at full amplitude of vibration and the 

coded permutation or combination is formed by 

the discontinuance of combinations of the audio 

frequency oscillations, the vibration of the affected reeds will drop below the amplitude which 

maintain continuous flow of current to the relays, 

thus presenting coded combinations as represented by the reeds remaining in contact. 

Practically all modern printing telegraph systems and equipment utilize the principle of se- quential application of some form of coded permutations or combinations. These methods re- quire accurate synchronism between transmitting 

and receiving points, in addition, the speed of 

these methods is limited by the requirement for 

linear translation of code permutations or com- binations in terms of time. Thus, if each coded 

permutation or combination is spaced Ys second 

apart, the limit is five characters per second. 

1:) 36, each having a key-return spring 3l, and an associated set of five selector bars 38 connected 

to key 36 by wires 39. Reference character 40 

represents five sets of electrical contacts which are closed in permutations or combinations when 

1:; a letter or other functional key 36 is depressed. 

Reference character 41 designates a multiple 

audio frequency oscillator-amplifier capable of 

generating five different audio frequency tones 

singly or in simultaneous permutations or com- 20 binations. Reference character 42 denotes a cou- pling transformer betwee.n the oscillator 41 and a modulator 43 which modulates the radio frequency carrier generated in the oscillator-amplifier equipment 44, which in turn radiates a 25 modulated radio frequency signal through an- tenna system 45. 

When key 36 is depressed the wires 39 pull 

down a combination of bars 38 which in turn close 

the electrical contacts 40, associated with each 

::JO bar. When the selected contacts 40 are closed 

the oscillators 41 associated with each set of con- tacts 40 which have been closed are caused to 

produce oscillations at the audio frequency to 

which they have been tuned. The output of the 

;i,3 actuated oscillator 41 is then combined in cou- pling transformer 42 which drives modulator 43 

causing the radio frequency output of amplifier 

44 to be modulated at the selected audio frequencies and radiated into space through an40 tenna 45. In addition to the method described, 

the audio frequency tones may be impressed upon a pair of conductors or upon a carrier frequency 

which is transmitted by wire lines instead of 

radiated into space. 

".> In Fig. 2 I have shown the schematic wiring 

diagram of the transmitter where the audio frequency oscillators are illustrated at 4Ja, 41b, 41c, 

41 d and 41 e, including resistance capacity cou- Pled oscillator circuits 46a, ,,6b, 46c, 46d and 46e 

;,o associated with oscillator amplifiers 4la, 4lb, 4lc. 

4ld and 4le respectively. The contacts 40 are shown for each of the respective oscillator systems at 40a, 40b, 40c, 4Dd and 4De connected tQ 

the transformer system 42 through which the 

;,;; selected audio frequencies are impressed upm;1 

modulator 43 for keying oscillator system 44 and 

impressing the selected modulated frequencies OD 

antenna system 45. 

By the simultaneous application of the coded 

permutations or combinations, as accomplished GO 

by my invention, no limitation in time of translation is involved and the speed is limited only 

Description of receiving system 

Fig. 3 is a block diagram of the receivino- svs- tem of my invention operating as a tape prfntlng 

telegraph de:vice. In operation the receiver 50 

picks up the radio signal emitted by antenna sys- by the ability of the translation mechanism to 

function. 

In the presently available printing telegraph 

systems and equipment, the sequentially spaced 

electrical or audio frequency impulses are transformed into coded mechanical positions which 

are mechanically translated into printed charactern. · In the method of my invention, the coded audio 

frequency impulses are translated into direct current impulses which are electrically translated 

into printed characters, thus greatly sPeeding up 

65 tern 1!5 of Figs. 1 and 2 on antenna system 51 and 

demodulates the signals and passes the rectified 

impulses through the field coils of tuned reed relays 52A, B, C, D, and E. These impulses cause 

the selected tuned reed relay armatures 53-A, B, 

iO C, D, and E to vibrate in resonance with the audio 

frequency tones selected to produce the desired 

permutation or combination. When the vibrating relay armatures 53A, B, C, D, or E Teach their 

amplitude of vibration, dire.ct cur,rent impuls.es 

75 are presented to the field coils of relays 54A, B. 
REF ID:A4161579 

2,658,942 

5 6 

.c, D, and E or a combination· thereof,· causing - The "make" and "space" contacts are arthe associated armatures 55A, B, C, D, or E of ranged and permanently wired in such a manner these relays to close a series of contacts in the that the movement of any one or a combination 

electrical matrix 56 which will close an electrical of moving actuators l&A, B, C, D, or E will propath to one position on the stepping relay 5J, ;) vide an electrical path through one and only one 

·this position having been selected when the of the thirty-two possible channels of the matrix 

proper key 36 of Fig. 1 was depressed. When the 56. The provision of this electrical path through 

position on stepping relay 57 is energized with any one of the first twenty-six channels of th~ 

.electrical current, the arm 58 being impulsed by matrix 56, allows current from the negative side 

ratchet iJ,rm 59, ratchet relay G2, and ratchet 10 of the power source to be placed on one of the 

wheel 60 connected to arm SB through shaft 61 twenty-six positions of the stepping relay 57. 

under control of the arm 58, starts stepping to- Channels 27, 28 and 29 of the Fig. 4 are shown 

:wards the energized position within a range of as being connected to the negative terminal or 

approximately 180°. ground of the power source. They are used to . Upon a,rrival of arm 58 at position A. printing 15 actuate the "Letters" relay 79 or "Figures" re-

:relay 81 is placed in short circuit across, con- lay 80 or the "space" relay 81. Channel 31 of 

·tacts 62a, 62b of ratchet relay 62, arresting the the matrix 56 is likewise shown as connected to 

movement of arm 58. The drum 64, being di- the negative source of battery or ground· and 

rectly coupled to the shaft 61 which carries arm is used to operate relay 82 for the control of a 58 through its stepping cycle, has on its periph- 20 positive source of battery to the stepping relay 

ery the type characters of the alphabet in the coil 62. 

lower case and the numerals and punctuation Each position A-Z is arranged within an anguin the upper case as shown more clearly in F'.ig. 5. lar space of approximately 180° on the stepping 

When arm 58 reaches the energized position A, relay 51 and is associated with a type character 

drum 64 carries the type character G4a to a po- z:; such as G4a on the drum o4, and when the arm 58 

sition immediately above printing arm 65 and is in contact with a position A, the type character 

tape 66. When relay 81 was energized by bein~ associated with that position or drum 64 is implaced in short circuit across contacts li2a,'. 62b, mediately above the printing arm 65 of relay 81. 

anvil 65a of arm 65 was caused to strike tape 65 ·"Letters" relay 19 and "Figures" relay 80 are which was in turn pressed against type character :rn normally energized through resistors 83 and 84 

64a causing that character to be printed on tape with only sufficient current to hold the armature 

.66, the type having been previously inked by 85 in position against the field magnet of the re.: 

inking wheel 67. i lay to which it was last attracted. When a com- Upon the release of key 36, Figs. l and 2.;arm bination of impulses are received which cause 

65 is returned to a normally open positio~ by ~,; channels 27 or 28 of matrix 56 to be completed, 

spring 68, and contact 69 is closed, causing the resistor 83 or 84 is shorted, causing the reratchet relay 111- 'to operate arm l I moving ratchet lay l 9 or 80, whichever is associated with the 

12 which in turn causes rollers "fl and 13 to turn, shorted resistor, to attract armature 85 to the 

advancing tape 66 one step forward from supply magnet of that relay. 

reel 66a. The release of key 36 of Figs. 1 and 2 40 Armature 85 is provided with a yoke 86 on the 

also removes the audio frequency tones thu~ re- end associated with the armature 65 of relay 81, 

turning all relays to their normal receiving, po- Figs. 3, 4 and 5, which moves the striking porsition. tion of armature 65 below the type character 64b, 

Fig. 4 is a schematic diagram. of the electrical to the upper case or "Figure" position or ·in the 

circuits used in the system described in Fig. 3, lower case or "Letter" position 64a in accordance 

wherein 50 represents the output_ of a radio, re- 45 with the desired position as determined by the 

ceiver or fand-line amplifier, 52A, B, C, D. al].d E channel operated as represented in Fig. 5. The are the field coils of the five resonant relays, 9on~ orientation of armature 65 to Figures or Letters 

tacts 14A, B, C, D, and E are the contacts on, the position is represented in dash lines in one limitvibrating reeds 53A, B, C, D, a.nd E of the resm;i.ant ing position and dot dash lines in the opposite 

relay 52A, B, C, D, and E. Reference chara~ters 50 limiting position in Fig. 5. The orientation of 

lSA. B, c. D, and E designate the field coils of the armature 65 is accomplished by yoke 86 

the five relays Sl!A, 54B, 54C, 54D, and 54E which which is moved under control of magnets 79 and 

operate tbe moving armatures 55A, B, C, D, and llO to swing armature G5 about the universal 

E of the electrical matrix 56. This matrix con- pivot 65b that allows the armature to pivot under 

sists of thirty-two channels made t!P by 160 n!ark 55 control of relay magnet 81 and to orient under 

and space contacts associated with the contacts control of relay magnets 19 and 80. Relay mag- on the five movable actuators 76A, B, C, D, and nets 19 and 80 are controlled by channels 91 and 

E. The "space" -contacts are represented as be- 92 responsive to code permutations and combiing below the contact arms of the movable con- nations for accomplishing Letters ·and Figures 

tact arm actuators 76A, B·, C, D, and E, that are 60 shift. 

operated by armatures SSA, B, C, D, and E. The The armature 85 carrying yoke 86 that engages 

space contacts are normally closed when relay armature 65 is shown broken away in Fig. 3 

coils l5A, B, c, D, and E are not energized. The to indicate that the yoke 86 has been oriented 

"mark" contacts are represented above the con- in position to explain the manner of engagement 

tact arms of the movable contact arm-actuators 65 thereof with the end of armature 55. · In prac75A; B, c, D, and·E.and are normally open when tice it will be understood that magnets 19 and 

relay coils 75A, B, c, D, and E are not energized: 80 would be viewed from the end thereof as wilf 

Energizing any one or_ a combination of .relay. •be clear by examining the plan view of Fig. 5. 

coils l5A. B, c, D, or .E will. cause .armatures 70 Stepping relay contacts 1-26 disposed within 

55A, B, c. D, or E .and the contacts. associated an· angular range of appi·oximately 180° control 

with the particular movable contact arm actu- the letters A-Z under control of contact arm 58. 

ators 76A. B, c, D, and E to be moved .and open The arrangement of contacts on the. stepping· 

all "space" contacts associated ·with the same relay comprising contacts 1-26 control the fig_ 

arm. . -· . . _ ... _ .... _ . _ 7lf ures and other symbols and punctuation ·and· 
REF ID:A4161579 

9,868,9'112 

"I 

other apei:iiai characters such as weather sym-

!:>Qls a.nd the like under supervision qf the second arm 94 extending in approximately diametrically 

opposJte position with respect to arm CiB and 

also Fotatable about shaft 61. 

It may be observed that the steppjng relay li'I 

is re-cycling and that the code wheel 64 has two 

complete alphabets, each occupying one-half the 

periphery of the wheel. The alphabets are asso- ciated with the respective arms 58 and 94. Since 

the device is re-cycling there is no need to reset 

the mechanism after the printing of each character since one of the rocking arms 58 and 94 

steP!) forward to the next character from the 

Position of the last printing. After one arm completes 180° travel the other arm picks up the 

rptation through 180°. 

The mechanism of my invention is extremely 

Compact in size because Of the arrangement of 

the control system. The dimensional arrange~ 

ment is such that the type wheel of drum 64 

and the associated tape advancing mechanism 

and the ratchet mechanism for controlling the 

movement of arms 58 and 94 are all located substantially within the dimensional limits of the 

approximately 180° angular range of the stepping relay 57. Thus, the printer unit takes on the appearance of the substantially 180° con- tact system A-Z which is located closely adjacent the type wheel and the associated operating 

parts and substantially embraces the dimensional 

limits thereof. 

Tape advance is accomplished by operating 

ratchet relay 20 which turns roller 11 by operating arm 71 to step ratchet 72 whenever contacts 

:69 are closed as a result of the release of arma- ture 65 by the removal of energy from relay coil ~I or by the completion of channel 29 of matrix 

56 as a result of the receipt of a "space" combination signal over channel 93. 

Operation 

The operation of the system of my invention 

is as follows: Assume it is desired to print the 

c)laracter Y which is represented by the simultaneous application of the tones produced by 

oscillators 41 a and 41 d. 

The letter key "Y" of keyboard 35 of Fig. 1 is 

depressed causing contacts 40 associated with 

pscillators 41 b and 4 Id to be closed. The output of these two oscillators causes modulator 43 

to modulate amplifier 44 at the frequency tones 

produced by oscillator 41 b and 41 d. The amplifier in turn emits these tones on a radio frequency carrier. 

Receiver and amplifier 50 pick up this emitted 

signal, demodulates and passes the rectified impl)lses a~ audio frequency tones to the coils of 

tuned reed relays 52B and 52D which begin vibrating at their resonant frequencies and when 

sufficient amplitude of vibration is attained, con- tacts are made at 74B and 74D which in turn causes field coils l5B and l&D of the relays 

64B and 54D to move armatures 55B and 55D 

which moves extended actuators 76B and 76D to one limiting position thereof, closing the marking 

contacts and opening the spacing contacts of the arms associated with actuators 76B and 760. 

With actuators l6B and 76D in the limiting position above described an electrical path is provided 

through channel I of matrix 66 from the negative side of the source of battery to relay coil fl I to 

contact 62b of stepping relay 62 on stepping 

switch 57. 

When actuators l6B and 76D are moved from 

tneir original position, the path through matrix 

8 

56 provided by channel 31 was interrupted, caus- ing current to be withdrawn from relay 82 allow·-

ing contact 81 to close. The closing of contact 

81 supplies current to stepping relay 62 from the 

5 positive source of battery through the winding 

of relay 62 and contacts 62b to the negative source of battery and ground, causing ratchet 

59 to start stepping arm 58. When arm 58 

arrives at position A, the upward stroke of arma- 10 ture 62a does not break the source of current, 

since by the closing of electrical circuit through 

channel I of matrix 56, the coil of relay 81 was placed across contact 82b, keeping coil 62 ener- gized which in turn stopped the movement of 

'15 armature 62a and ratchet 59. When the move- ment of arm 58 was arrested the rotation of drum 

64 was also stopped at a position where the letter 

"Y" was immediately above tape 66 and armature 

65 striking surface 65a. The electrical energy 

-2!l which provided the holding current for relay 62 

to arrest the movement of arm 58 also passed 

through relay coil 81 causing armature 65 to move upward which pressed tape 66 against the 

letter "Y," causing the letter "Y" to be printed 

25 on tape 66. 

As previously described, the return of key "Y" 

to normal position on keyboard 35 of Fig. 1 re- moved the output of oscillators 41 b and 41 c from 

modulator 43 and amplifier 44, which in turn 

30 caused tuned reeds 52B and 52D to discontinue 

vibration, breaking contacts 74B and 74D allowing relays 54B and 54D to return to normal which 

moved actuators 76B and 76D to their original 

position. In this position channel 31 was closed 

3:, which closed relay 81 removing the battery source from relay 81 and stepping relay 57. The re- moval of energy from relay 81 caused contacts 69 

to close providing an electrical circuit from the 

positive side of the battery source through relay 

,10 lO to the negative battery supply which in turn 

caused relay armature 71 to operate ratchet 72 

moving rollers 11 and 78 advancing tape 66 one step forward. 

While my invention as hereinbefore described 

ctJ has been illustrated as applied to a tape type 

of printer, the operation may be applied to a page type printer by replacing the stepping relay 

58 and associated apparatus with a conventional 

electric typewriter. 

50 The thirty-two channels of matrix 116 are then 

used to provide an electrical circuit to a series 

of thirty two solenoids or relays which are used 

to operate the mechanism of the electric typewriter which performs the typing, carriage re- turn, line feed, spacing and upper and lower case 55 functions. 

In applications where more or less than thirty 

two operations are required, the number of os- cillators, tuned reeds and associated relays ;may 

be rearranged in a matrix which will perform 60 the number of functions required. 

One such application is in the use of drums to 

visually present pre-arranged or recorded information. 

Where the number of displays to be presented 65 are less than sixteen, four tones, four tuned 

reeds, a sixteen channel matrix and a sixteen 

position stepping relay with the messages printed 

on a cylindrical surface such as the drum 64 of 

70 Figs. 3 and 4, can be formed into a light weight 

system of visual telegraphy particularly adapted 

to aviation traffic control communications. 

Another application of my invention is an arrangement of the matrix 56 where one channel 

75 is permanently wired in a fixed position in such 
REF ID:A4161579 

2,658,942 

9 a manner that only when a signal consisting of 

the· proper combination of tones is received will 

it pass through the matrix. Such an application 

being particularly adapted to selective calling 

systems illustrates the versatile character of the 5 

system of my invention. 

The matrix 56 illustrated in Fig. 4 shows in 

diagrammatic form the graphic appearance of 

the code symbols used in the system of my ,invention. These are standard code characters of 1 o the international Teletype code with respect to 

the sequential arrangement of th.e mar}{ and 

space signal impulses. The equipment of my 'invention is accordingly interchangeable vhth 

standard Teletype equipment and is operative l 5 over the same channels on which standard Teletype equipment is being operated. 

I have found the equipment of my invention 

highly practical in construction and operat'ion 

and while I have described my invention in cer- 20 

ta.in preferred embodiments I realize that mqdi-

:fications may be made and I desire that it' be 

understood that no limitations upon my invention are intended other than may be imposed 

10 

cuit connections establishing a signal combination representative of a predetermined character, 

a m1:J:!~jg:J!Y,2f,J!.La~~,t!;Q!~~ .. ~~W,. ~~,Jll­ taneous applieC:l multiple_ coded __ signal iajpJ;!lses 

for ~renderiili~safd'e1ectriC:'·mafrix cfrcuits individuall:Yand.- sciectfvely~effective.~·a,~printing 

controi mecJ:laniSffiillcluding a type wheel wherein a complete alphabet appears on each 180° of 

the type wheel, and a stepping relay associated 

with said printing control mechanism and operative through a range of approximately 180° under 

control of said simultaneously applied multiple 

coded signal impulses for selecting one of said 

electric matrix circuits and effecting thereby the 

printing of a selected character by said printing 

control mechanism. 

4. A printing telegraph receivi.!!g_~tem as set 

forth in claim 3 wherein tlfe"simultaneously ap.., 

plie2._p .~}tip~~ cQg~<Lsig_nc~l . imp\ffie_~~ li1:Tfe'Ceived 

at auC:lio frequencies and effect the establishment 

of circuits through the electric matrix circuits 

for the passage of direct current pulses to said 

printing control mechanism. 

by the scope of the appended claims. · 

As an example of one of the variations or mo;dift.cations of my invention I may refer to ~ny 

means for constantly activating the several reeds 

5. A printing telegraph receiving system as set 

'.'.i forth in claim 3 in which tne sniilirtaneously applied multiple coded signal _impulses are received 

at audio frequenciesancte1fect resonant vibra_-

tion of a multiplicity of reeds and which in turri so that they are maintained in a· state of vibration. Such constant rate of vibration is at 1an ;;:) 

amplitude at which electrical contact is maintained by the reed contact. However, upon non- receipt of a tone the reed resonant to such tone 

may be dropped in amplitude of vibration sufficient to effect the release of the associated con- ~!;:; 

tact. Thus a slight infinitesimal time lag in'cidental to building up the vibration of the reed 

is eliminated in such an arrangement by ha vlng 

the reeds operate at full amplitude of vibration 

which is interrupted by the displacement of a .;:1 

frequency or combination thereof. , What I claim as new and desire to secure 'by 

Letters Patent of the United States is as follows: 

1. In a printing telegraph receiving system, means for receiving permutations andcombinations of simultaneously applied multiple coded ·~ .) 

signal impulses, a ratchet controlled step-by-step 

selector system operative over a range of approximately 180°, a printing device including a 

type wheel wherein a complete alphabet appears ,·;o on each 180° Of the type wheel operatively con- trolled by said selector system, and electric cir·-

cuit means for simultaneously applying said permutations and combinations of simultaneously 

applied coded signal impulses to said ratchet con- :!! 

trolled step-by-step selector system for controlling said printing device by the conjoint action 

of simultaneously applied impulses. 

2. In a printing telegraph receiving system, means for receiving permutationsarurcombinations of simultaneously applied multiple coded U::! 

audio frequency signal impulses, electric circuit means :for translating said simultaneously applied 

multiple audio frequency signal impulses into 

simultaneous direct current impulses and means n.! 

including a type wheel wherein a complete alphabet appears on each 180° of the type wheel 

and operative through a range of approximately 

180° for electrically translating said simultaneous 

direct current impulses into printed characters. 70 

3. In a printing telegraph receiving system, 

means for receiving permutatioii'San(fcombinations of simultaneously applied multiple coded 

signal impulses, a multiplicity of pre-arranged 

electric matrix circuits, including individual cir- i5 

control direct current relay circuits for selectively 

conditioning an individual electric matrix circuit 

representative of the selected character in said 

multiplicity of electric matrix circuits. 

6. A printing telegraph receiving system as set 

forth in claim 2 in which saicrtranslating means include a multiplicity Of reeds individually reso- nant to the individual frequencies of said simultaneously applied multiple coded signal impulses 

and direct current acti:iaf:ed relay circuits con-- trolled subsequent to the attainment of a predetermined amplitude by said reeds. 

7. A printing telegraph receiving system as set 

forth in claim 1 including a tape'feed mechanism 

for advancing a tape longitudinally of the path 

of both of the alphabets on said type wheel and a striker bar selectively orientatable to a position 

aligned with either of said alphabets for presenting the tape to either row of alphabets on said type wheel. 

8. In a printing telegraph receiving system, means for receiving permutations and combinations of simultaneously applied multiple coded 

signal impulses, a selector switch controlled by 

said impulses, a printing device including a type 

wheel wherein a complete alphabet appears on each 180° of the type wheel, and means disposed 

within dimensional limits of approximately 180° 

and controlled by said selector switch for con-· trolling said printing device said means also in--

eluding a matrix of electrical circuits beyond the 

aforesaid dimensional limits containing prearranged circuits individual to the permutation and 

combination signal impulses representative of 

each of the characters being printed. 

9. In a printing telegraph receiving system, means for receiving ·multiple permutations and 

combinations of simultaneously applied multiple 

coded signal impulses, a converter including a 

multiplicity of individually resonant reeds, responsive to the multiple coded signal impulses, 

individual relay contacts controlled by each of 

said reeds and operative to establish closed electrical circuits when said reeds are vibrated substantially at resonance, separate relays controlled 

by each of said relay contacts, an armature and 

actuator individual to each of said last mentioned 
REF ID:A4161579 

2,.Q58,Q.42 

11 r~l_ay.& •. a_ muJ_tiplicity oi co11ta_ct a:r.ms c_qnt_rolled 

l;>Y. e!J.!<0.. Qf s_aJd !J.ct.uator.:;. ari eljlctrlc. matri)C_ ipcluding contacts associated_ with each, of sakt con'-

tac:t' arms arici connected ill circuits corresponding 

in"inimber "to" the number -cii'eiectricai pulses be:- 5 

i,I)g_ t_ianslI).itt_eq, a st_eppjp.g relay· baying a multipij_ci:t;Y, of radial]y qisposed c_ont_act μqsit_i_ons disposejj: within an an~J!j,r raJJ.g.e of aμproximately 

i80° corresponding_ in nl}mber to the, number_ of 

electrical circuits through said electric ma.trix IQ 

and electrically- connected·. to the contacts there12 

telegi::aJ?h, device. wlth said }ast. mentiQned. CQik 

tacts and effecting, the. Printing, of a. cha:i:act_er 

correspQz:i.ding, t.o. the signal permutation a.ru1 

cQmbination establishe_d by individual pa.tbs 

through_ said electrical matrix .. 11. A printing telegraph receiver comprising. a s_tep-by-step selectornavmg a iiiwtiplicity. of 

contacts. forming circuit termmals. or permuta,-

tion and combination direct. current pulses, c_or.-

responding to signals and arranged. iii a curV;ed 

path extending through approximately -180° .. a 

pair of rocking arms. selectiv:ely mo:v;abfo. o:ver 

said contacts,, a. type-wheel having_ a double. al~ 

pbabet printing- face thereon, one alpha.Qet, o! 

which extends o:ver_ 180_0 of the. type wheel. and 

the other alpha!Jet. of which. extends o:v.er the 

other 180° of the_ type_ wbeel,. means. f.or. driyillg 

said typ_e wheel in. timed "relation to, the movement Of said rocking arms._ a tape_ movable ad.-

of, -a stepping. -re~ay arrn. OI)erative over said 

radially dispose_d contacts within an angJJlar 

range_ of approximately 1so0 and a printing device 

including_~ type_ wheel wherein a complete-alpha:- 15 

bet appears on each 180° of the_ tyP.e wheel apd 

selectively controlled by said_ stepping relay aim 

and i:esponsiy:e t<> selected sigp.al permutatioI1s 

and combinations establishe_d tbr.o.-ug:tl s_aid_ 

ma tr~. 20 jacent the- double alphabet p:rinting; face. e!, said 

typ_e_ wheel, and means. for selectively- mov.ing -

s:iid tape- into_ register with. either. alphabet on sajd_ do.uble. alphabet, typ_e. wheel,. said double 

- 10~ In a printing telegraph, r.eceiving: SY.SteIIJ., 

a_ recei_ving circuit respo_nsive t_o a'Pi"e!ie:te'fl;ll.i1led 

range Of audio frequency permu_tatiOJJ_S arid_ CQii}:-

binations of signal imriuises, a m_WtiP.licity of 

tuned_. reed- relays indiyid"ualiy responsiv.e t_q aμd_io 25 

frequency signal impulses within said_ pre_det.erinin~d range or- aμdio freqμency,_ said_ tuned :r_eed 

relays ea_cJj in<;luding a vibratci1'.y armature ariQ 

a- contact member spacially r_elated' theret.o whe_rel;>y s~lect_ed electrical cjrcuits_ are close_d_ through 30 

said armatures arid their associated contacts 

when- the vibration Of said armatures .reac_hes_ ii, 

predetermined. amplitud~. direct cur:re11t_ relays 

each hav~g _relay ~ipdin~s electricalJ.Y. c_onnec.te_d 

with th!l af9:r_e_s_aid contacts and: a squrc_e ot djr:ecJ 3;"> 

curre_nt; an armature assQci_ated wit;h eac_h Qf s_ajd 

direct cui:rent r_elays, a m_ovab_le a,_ctuator. c_QI1_-

nected- with each of· said last mentioned· arma- tures, a multiplic_ity. Of contact arnis CO_ntr_qll_lid 

by- each of· said movable actuators._ said: c_onta,_ct 40 

arms corresponding· in number. to tpe nui:nber. of 

signal permutations- and combinations iIJ_cide_nt 

upon said receiving- circuit, con.tact elements asSOciated with e~c_[l Of said· contact arms._ elec_trical 

cfrcuit connections extending_ from the contact 45 

elements associated with the -contact arms" controlled by one of said -act_uators witq the c_c:intact arms controlled' by the adjacent_ ac.tuat()r_ i:i,nq· 

·forming an electrical matr_ix having Qirc.uit. pajJls 

therethrough individ4al to each or-the signa,tp.e1:- 50 

mutations and combinations incident upon said 

receiving· circuit: a"steppi:Ilg rela~ ~cl:uci_illg. -iii:-

dividual- contact_s c()nn.ected_ to the aforesaid cir_-

cuit connections; contac_t arms movabte o_ver. said: 

individual' contacts, a pr_inting: telegrapb. devic.~ 5;; 

including-a type Wheel whereill_ a QOmI?lete alp_lliJ,-:-

bet appears on each 180°' of the type wheel, and 

means for selectivel31 co!Jllecting:' said: -Piin!;.irig_ 

alpl:labet t~pe wheel. being, mounted-. within t)le 

curved path of said multiplicity, of, contacts, 

-12._ A printing_ te1£.gM@_.J;.~ comprising a step-by-step selector baving_ a . multiplicity, o! 

c_ontacts forming circuit. termillals, for permU,ta.;-c 

tion and. combination. direct. curr.ent. pulses, cor.,-. 

responding_ to signals_ and. arrang,ed in. a-_ cur,v.ed. 

path. extending, through _approximately, la<i~. a rocking_ arm. mo:v.able unidir.ectionaUY, · step,-bY,-

sJ;ep. f()i: sel.ectiyelY. sweeping, said. contai::ts.. a shaft extending from said arm,, a.z:a.tchet inecha--

ni$m c()ru;i.e_c_t_e_d witb," said_ shaft. for_ · imP,a1.1tirig, 

un_iqir_ectional, st_ep,-by.-steP,- movement, tbereto,, a typ_e_ wheel_ conne_cted. with said: shaft_. and can;y;-

ing type_ designations constituting a. complete 

alphabet appeariilg, on each. 180? of .the--p_e_riph,. 

ery. thereof, a tape movable. tangentially.- to, the 

designations on the. periphery Of said, type. wheel.. 

i:i,nd_ means for selectively mo;ving a. tape, into 

register. with the_ designations on the, per.ipher.y..-

of. the type, wheel. · 

JAMES D._ DURKEE .. 

References. Cited in the file of this. patent. 

UNITED. STATES PATEN.rs 

Number 

2,056;452 

2,058;398 

2,096,954 

2,173;154 

2,192,242 

2;262;766 

2,342,886 

2,406,835 

Name- Ba-teHoover et al. ________ Oct; 6; 1936 

Bear-----------~-~-- Oct. 27, 1935· 

Bellamy et al'.-------- Oct. 26, 1937 

Bernard:---------- Sept. 19; 1939· 

Robinson et· aL ------ Mar~ 5, 1940· 

Jansso:n ------------ Nov. 18, 194'1 Murphy- ____________ Feb. 29; 1944'. 

Herbst-------------- Sept. 3; 1946' 

I· 

i 
June -15, 1954-- -

Filed July 28, 1952 

REF ID:A4161579 

. J. D. DURKEE 

MECHANICAL MOVEMENT 

2,680,970 

2 Sheets-Sheet l 

INVENTOR 

Jaznes _JJ. Dur.Kee 

BY~~~~ ATTORNEYS 
June 15, 19.54 

riled July 28, 1952 

8.5 

REF·ID:A4161579 

J. D. DURKEE 

MECHANICAL MOVEMENT 

113 \ ----J.-........_ 

__::::::--

,lfZ 

I 

~--L... 

/ .--... 

2,680,970 

2 Sheets-Sheet 2 

---,-~. 

-.96 ((10 -~4. 

J.\'VENTOR 

1:\tf~~q._~ 

A TTOI~ I\' EY.S 
REF ID:A4161579 

Patented June 15, 1954 2 ego 970 ,u ~ 

UNITED STATES PATENT OFFICE 

2,680,970 

MECHANICAL MOVEMENT 

James D. Durkee, Arlington, Va., assignor, by direct and mesne assignments, to Dualex Corporation, a corporation of Delaware 

Application July 28, 1952, Serial No. 301,402 

8 Claims. (Cl. 74-96) 

1 2 

The present invention relates to mechanism 

for rapidly moving and accurately positioning a 

mechanical element in any of a plurality of prescribed positions. The invention is of general 

utility, but by way of example of one field of use 5 

reference may be made to the positioning of a printer wheel of a telegraphic typewriter. A 

printer wheel for a telegraphic typewriter must 

tied form of apparatus embodying the invention; 

and 

Figure 4 is a front elevational view of still 

:mother embodiment of the invention. 

The arrangement illustrated in Figures 1 and 

2 includes a printer wheel 6 having a type bar 1 

thereon. The type bar l carries a plurality of 

printing characters, not shown, which are cirbe properly positioned to present the desired cumferentially spaced and which are intended to 

character to the inked ribbon and the paper. 

The positioning must be precise for neatness of 

the typewritten material. The movement of ~he 

printer wheel from one prescribed position! to 

another must occur very rapidly in order for the 

typewriter to be capable of high speed. There 

are many other fields of utility for mechanisms 

capable of rapidly and precisely positioning a mechanical element in any of a plurality of desired 

positions. 1 One of the primary objects of my invention 

is to provide a mechanical linkage which is capable of rapidly and accurately positioning a mechanical element in any one of a number of :desired positions. Another object of the invention 

is to provide such a mechanism which is extremely 

simple so that it can be produced economically 

and so that there is a minimum of expense: for 

maintenance or repair. Still another object of 

the invention is to provide such a mechanism in 

combination with a plurality of motors or dfiVe 

means, which motors or drive means are identical 

in order to reduce costs and to simplify repairs. 

Still another object of the invention is to provide 

mechanism of the type described in which : the 

mechanical element to be positioned has an I as- signed. neutral position which is intermediate its 

other positions. The mechanical element cai:i be 

moved from ·its neutral position to any of'. its 

other positions by traveling through a shorter 

path than would be the case if the element'::; 

assigned neutral positions were otherwise placed. 

Still another object of the invention is to provide 

mechanism of the type described which provides 

for relatively slow acceleration and/or deceleration of the mechanical element. 

The foregoing and other objects and advantages of the invention will be more fully understood by reference to the following description 

taken in connection with the accompanying 

drawing, wherein: 

Figure 1 is a front elevational view of mechanism embodying my invention arranged to control the movement of a printer wheel, the mechanism and the printer wheel being shown in the 

neutral position; 

Figure 2 is a front elevational view of the 

apparatus shown in Figure 1 but illustrating the 

printer wheel moved to its extreme position in 

one direction from the neutral position; 

10 be presented selectively to a printing zone which 

is diagrammatically indicated by the reference 

numeral 8. The printing wheel must be oscillated to present the desired printing characters 

to the printing zone and this oscillatory move15 ment must occur rapidly in order that the machine may print at high speed. The positioning 

of the printer wheel must be precise for each of 

its angular positions in order that the printed 

characters will be neatly and accurately disposed 

20 on the paper. 

The printer wheel is provided with a fixed 

axis of rotation 9. A radially extending ::;lot I 0 

is provided in the printer wheel. This slot receives a pivot pin· 11 which is free to slide therein. 

25 The pivot pin 11 pivotally connects the ends of a 

pair of actuator links 12 and 13. The opposite 

end of the actuator link 12 is pivotally connected 

to a base link 111 while the actuator link 13 is 

similarly connected to a base link 15. The base 

30 links 14 and 15 are independently oscillatable 

about a fixed axis 16. In this form of the invention the base links 14 and 15 are independently 

oscillatable about the same fixed axis, although in 

forms of the invention hereinafter described 

35 these links are oscillatable about axes which are 

not coincident. 

The base link 14 is provided with a stop mem- ber I l which limits its outward movement. A 

tension spring member 18 resiliently biases the 

40 base link 11! into position against the stop member I l. The base link 15 is provided with a similar :otop member 19 and a tension spring 

member 20. The stop members 11 and 19 and 

the spring members 18 and 20 determine definite 

45 normal posi.tions for the base links 14 and 15, to 

which those links will turn when permitted to 

do so. 

Figure 1 illustrates the base links 11! and 15 

in their norms,! positions. Under such circum50 stances the printer wheel Ii occupies a definite 

position which may be termed its neutral position. In this neutral position one printing character may be presented to the printing zone 8, 

ancl i~ is unnecessary to oscillate the printing 

55 wheel G to print such character. Figure 2 of the 

drawing. illustrates the condition of the mechanism when it has been actuated to move the 

printer wheel to its extreme position in a 

Figure 3 is a front elevational view of a modi- llO 

counterclockwise direction. The base link 15 still 

occupies its normal position against the stop 
REF ID:A4161579 

2,680,970 

3 

member 19, but the base link 14 has been oscillated to the position shown in the drawing. The 

pivot pin I I, engaging as it does the walls of the 

slot ID, has caused the printer wheel 6 to oscillate 

to the position shown in Figure 2. It will be apparent from an inspection of Figures 1 and 2 that 

a lesser movement of the base link 14 would result in a lesser extent of oscillation of the printer 

wheel 5 in the counterclockwise direction. It will 

also be apparent from an inspection of these figures that movement of the base link 15 away from 

its stop member 19 will cause oscillation of the 

printer whee1 G in a clockw.ise direction, the extent of such oscillatory movement of the printer 

wheel being dependent on the extent of movement of the base link 15. 

Means for effectL."lg oscillatory movement of 

the base links 14 and 15 are illustrated as identical solenoids 21 to 28, inclusive. The solenoids 

2 I to 24, inclusive, are positioned along the base 

link 14 at different distances from the fixed axis 

16. The solenoids 25 to 28, inclusive, are positioned along the base link 15 at different distances from the fixed axis l 6. Figure 2 illustrates the solenoid 21 as being energized. Its 

plunger has engaged the base link 14 and, since 

the solenoid 2 I is positioned near the axis 16, the 

extent of movement of the base link I 4 has been 

greater than would be the case with energization 

of the solenoids 22, 23 or 24. It will be readily 

understood that energization of the solenoid 22 

would cause somewhat lesser counterclockwise 

movement of the printer wheel than that shown 

in Figure 2, whereas energization of solenoids 23 

or 24 would cause progressively lesser such move- ment of the printer wheel. Energization of the 

solenoid 25 will cause maximum movement of the 

printer wheel in a clockwise direction, whereas 

energ-ization of solenoids 26, 27 or 23 will cause progressively lesser movement of the printer 

wheel in that direction. All movements of the 

base links 14 and l 5 occur in opposition to the 

resilient action of the springs I a or 20, 8nd those 

springs serve to immediately ret~rn the base links 

to their normal positions upon deenergization of 

the solenoids. 

By energizing the proper one of the solenoids 

21 to 28, the printer wheel may be moved to a position to present any desired printing character to the printing zone 8. Preferably only one 

of the solenoids should be energized at .any one 

time, although there may be some slight over- lapping of the intervals during. which the various 

solenoids are energized. The movement of the 

printer wheel 6 will occur very rapidly and its 

position will be very precisely determined by the 

mechanism. The printer wheel will return to its 

neutral position as shown in Figure 1 immediately upon deenergization of the solenoids. Since 

the neutral position of the printer wheel is a position intermediate its other positions, it will be 

seen that the wheel can move from the neutral 

position to any other desired position by traveling 

through a relatively small angle. 

The embodiment of the invention illustrated 

in Figure 3 differs considerably in appearance 

from the arrangement described above but it embodies the fundamental concepts of the invention. A base link 51 is oscillatable about a fixed 

axis 52. A similar base link 53 is oscillatable 

about a fixed axis 54. A fixed plate 55 is provided 

with slots 56 and 57 which form guideways for 

the free ends of the base links 51 and 53. The 

end 58 of the slot 56 forms a stop member which 

defines a normal position for the base link 51. 

4 

The end 59 of the slot 57 forms a stop member 

which determines the normal position for the 

base link 53. The base links 5 I and 53 are resiliently biased toward their normal positions by 

5 means of the tension spring member 60. 

An actuator link 61 is pivotally connected to 

the base link 51 at 62 and an actuator link 63 

is pivotally connected to the base link 53 at 64. 

A pivot pin 65 pivotally connects the inner ends 

10 of the actuator links 61 and 63. The pivot pin 

65 is slidably received in a slot 66 of a lever 67. 

The lever 61 is pivotally mounted on a fixed axis 

:33 and the eu.d of the lever opposite the slot 65 

is fixedly secured by means of a suitable fasten15 ing means 59 to a suitable mechanical element 

such as a printing wheel 70. The printing wheel 

10 is oscillatable about the fixed axis 68. 

A plurality of oscillatory motors 11, 72, 13 and 

i'4 are poflitf.cncrl adjacent the base link 51 at 

20 different distances from the fixed axis 52. A 

plurality of similar oscillatory motors 75, 76, 11 

and 78 are positioned adjacent the base link 53 

at different distances from the fixed axis 54. The 

oscillatory motors are preferably electrically 

2:) actuated and are identical in construction. The 

operation of the oscillatory motor 11 will be described, it being understood that the other oscillatory motors operate in the same manner. The 

oscillatory motor 11 has an arm 79 which occu- :10 pies the position shown in full lines when the 

motor is deenergized. Upon energization of the 

motor 11 the arm 19 moves to the dotted line 

position 19'. In so moving, the arm 19 causes 

the base link 53 to move to the dotted line posi35 ti on 53 ', the actuator link 63 to move to the dotted line position 63', and the lever 61 to move 

to the dotted line position 61'. Movement of the 

lever 61 causes the printer wheel 70 to move to the dotted line position 10'. It will be under40 stood that energization of any other oscillatory 

motor will cause its associated base link to move away from its respective stop member, and that 

the extent of movement of a base linl~ will be dependent on the distance of the energized oscil-

" '' latory motor from the fixed axis about which the 

base link operates. By energizing the proper 

motors 71 to 78, the printer wheel 10 will be 

moved quickly and accurately to any of its prescribed positions. Four oscillatory motors have 

50 been shown associated with each base link, but 

this number can be increased or decreased as re- quired. 

Attention should be called to the arrangement 

of the arms of the oscillatory motors l l to 78 rel55 ative to the associated base links 51 and 53. By 

reference to the arm 79 of the motor n it can be 

seen that initial clockwise movement of that arm 

will cause rapid initial movement of the base link 

53. However, as the arm 79 approaches the dotted 

GO line position 79', the rate of movement of the 

base link 53 will be substantially lower. Thus the 

printer wheel lO will be given a rapid rate of 

initial movement and this rate will gradually decelerate as the printer wheel approaches its pre66 scribed position. This is a distinct advantage in 

that it eliminates the shock which would result 

from sudden deceleration or sudden stopping of 

the printer wheel. 

The form of the invention illustrated in Fig70 ure 4 embodies the fundamental concepts of the 

invention and additionally possesses certain advantages over the arrangements described above. 

A base link 80 is oscil!atable abount a fixed axis 

81 and a base link 82 is oscillatable about a fixed 

71; axis 8~. The base link 80 is provided with an 
, ·-:·-

REF ID:A4161579 

2,680,970 

s 

angularly extending arm 84 which is arranged to 

engage a fixed stop member B5 which determines 

the normal position of the base link BO. The base 

link 80 is biased to Jts normal position by means 

of the tension spring member BG. The base link 5 

82 is provided with angularly extending portions 

8l and 88. The angularly extending portion 87 

is arranged to engage a fixed stop member 8!! 

which determines the normal position for the 

base link 82. The bs.se link 82 is biased toward JO 

its normal position by means of a tension spring 

member 90. 

An actuator link 9 I is pivotally connected to 

the base link 82 by means of a pin 92. An actuator link 93 is pivotally connected by a pin 94 to l 5 

the base link 80. The actuator link 91 is pivotally 

connected to the actuator link 93 by means of the 

pivot pin 95. The actuator link 93 is shown as 

extending beyond the pivot pin 95 and as being 

connected by means of a pin 96 to a connector 97 20 

which may lead to any mechanical element the 

position of which it is desired to control. 1 

A plurality of oscillatory motors I 00, I 0 I, and 

I 02 are positioned adjacent the base link 80 at 

different distances from the fixed axis 81. Oscil- 25 

latory motors I 03, I 04, I 05 and I 06 are positioned 

adjacent the base link 82 at different distances 

from the fixed axis 83. The motors I 0 I to I 06, 

inclusive, may be the same as those described 

above in connection with the embodiment of the 30 

invention illustrated in Figure 3. It will be seen that energization of ::my of these motors will alter 

the position of the base link with which it is asso- ciated and that the position of the pivot pin 96 

is controlled by the positions of the base links BO 36 

and 82. 

8 

dash lirie 110. Similarly, when the base link 82 

is moved slowly there will be no movement of the 

base link 80 and the pin 96 will follow the dotdash line 111. When the base link 80 is moved 

very suddenly from its normal position, there 

will be a momentary movement of the base link 

82 from its normal position and the pin 96 will 

follow a path such as that illustrated by the 

dotted line 112. Similarly, the imparting of very 

rapid and sudden motion to the base link 82 will 

cause momentary departure of the base link 80 

from its normal position and the pin 96 will fol-

!ov: a path st:ch as that illustrated by the dotted 

line 113. 

The fact that rapid operation of the form of 

the invention illustrated in Figure 4 causes the 

pin 96 to follow the dotted line paths 112 or 113 

results in more gradual acceleration from rest of 

the mechanical element to which the connector 

97 is attached. .For the reasons pointed out above 

in the description of Figure 3, the oscillatory 

motors 100 to 106, inclusive, impart rather rapid 

initial movement to the base links 80 and !!2 

followed by gradu9.l deceleration of such movement. The more gradual acceleration resulting 

from the pin 96 following the paths 112 and 113 

in combination with the gradual deceleration resulting from the particular arrangement of the 

oscillatory motors relative to the base links gives 

a very smooth operation which is free from excessively sudden accelerations or decelerations of 

the controlled element. 

It will be seen from the foregoing detailed description that I have provided a variety of mechanisms capable of accomplishing the enumerated 

objects of the invention. The illustrated em- bodiments are to be considered as exemplary only 

and the broader scope of the invention is defined 

by the following claims. 

Having thus described my invention, I claim: 

1. Mechanism for selectively moving a pivot 

pin to any of a plurality of prescribed positions 

on either side of an intermediate neutral position, comprising a pair of base links which are 

independently oscillatable about fixed axes, stop means which determine definite normal positions 

for said base links, means for biasing said base 

links to engage said stop means, a pair of actuator 

links pivotally connected to said base links at 

points spaced from the said axes thereof, said 

actuator links being pivotally connected together 

by a pivot pin which occupies a definite neutral 

position when both of said base links are in their 

normal positions and which moves in one direction from said neutral position upon oscillation 

of one of said base links and in the opposite din~ction from said neutral position upon oscillat.ion 

of the other of said base links, and means for 

independently oscillating sa,id base links by con. 

trolled amounts from their normal positions 

whereby said pivot pin may be selectively moved 

to prescribed positions on either side of its said 

neutral position. 

2. Mechanism for selectively moving a pivot 

As indicated above, the embodiment of the invention illustrated in Figure 4 possesses advantageous characteristics which are not present in 

the forms of the invention described above. In 40 

the forms of the invention of Figures 1 to 3, movement of one of the base links of the mechanism 

creates no forces tending to move the other base 

link away from its stop member. For that reason, in the arrangements of Figures 1 to 3, either 45 

base link of the mt:rhanism may be moved and 

there is no movem~nt of the other base link of 

the mechanism. However, in the arrangement of 

Figure 4, movement of the base link 80 or the base 

link 82 sets up forces which tend to move the :.o 

other base link from its normal position. This 

phenomenon has definite advantages in a rapidly 

operating mechanism such as is required in a 

printing machine operating at high speed. The 

tendency of the opposite base link to move in re- :i::; 

sponse to positive actuation of one of the base 

links is opposed by the inertia of such opposite 

base link and by the tension spring member tending to bias such opposite link toward its normal 

position. However, when one of the linlcs is 60 

moved very quickly, the opposite link will overcome its own inertia and the effect of its biasing, 

and will momentarily move from its normal position, to be quickly returned, however, to such 

normal position by it.s biasing spring member. li:'i pin to any of a plurality of prescribed positions 

on either side of an intermediate neutral position, 

comprising a pair of base links which are independently oscillatable about fixed axes, stop means 

The foregoing phenomenon may be understood 

by referring to the paths of movement of the 

pin 96 under various conditions of operation. If 

the base link BO is mc,;ved relatively slowly from 

its normal position shown in the drawing,. the 70 

forces tending to move base link 82 will be insufficient to overcome the inertia of base link 82 and 

the action of spring member 90. Under such conditions, the base link B2 will not move and the 

pin 96 will follow the path designated by the dot- 75 

which determine definite normal positions for 

said base links, means for biasing said base linl;:s 

to engage said stop means, a pair of actuator 

links pivotally connected to said base links at 

points spaced from the said axes thereof, said 

actuator links being pivotally connected together 

by a pivot pin which occupies a definite neutral 
REF ID:A4161579 

2,680,970 

7 8 

position when both of said base links are in their said associated base link, whereby upon selective 

normal positions and which moves in one direc- energization of su~h motors said pivot pin may 

tion from said neutral position upon oscillation be selectively moved to prescribed positions on 

of one of said base links and in the opposite direc- either side of its said neutral position. 

tion from said neutral position upon o3ci1Jat.1o;--, 5 6. Mechanism for selectively moving a pivot pin 

of the other of said base links, and a plurality of to any of a plurality of prescribed positions on 

soienoids positioned along said base links [l.t clif- either side of an intermediate neutral position, 

ferent distances from said fixed axes, each cf s::i.ic. comprising a pair of base links which are indesolenoids being arranged, upon energization, to pendently oscillatable about fixed axes, means for 

oscillate its associated base link from its normal HJ biasing said base links against stop means which 

position by an amount dependent on the distance determine definite normal positions for said base 

of such solenoid from the fixed axis of said asso- links, a pair of actuator links pivotally connected 

ciated base lin!;;:, whereby upon selec~;i.vc el1er~i- to r;aid totse links at points spaced from the said 

zation of such solenoids said pivot pin may be se- fixed axes thereof, said actuator links being pivotlectively moved to prescribed positions on either 15 ally connected together by a pivot pin which ocGide of its said neutral position. cupies a definite neutral position when both of 

3. Mechanism as described in claim 2 in which said base links are in their said normal positions, 

the said fixed axes of said base link:c a"·e r::o:n- ;:;~.eans for oscillating a first of said base links by 

cident. 3, definite amount from its normal position to 

4. Mechanism for selectively moving ::i pivr.:i; 20 thereby move said pivot pin to a prescribed posipin to any of a plurality of prescribed pe.:;itions tion on one side of its said neutral position, and 

on either side of an intermediate neutral posi.tion, means for oscillating the second of said base linlts ;: 

comprising a pair of base links which are inae- by a definite amount from its normal position to 

pendently oscillatable about fixed axe::;, stop thereby move said pivot pin to a prescribed posimeans which determine definite normal po3itions 25 tion on the opposite side of its said neutral posifor said base links, means for biasing said base tion. 

lini'.s ·toward said stop means, a pair of actuator 7. Mechanism comprising a pair of base links 

links pivotally connected to said base links at which are independently oscillatable about. fixed 

points spaced from the said axes thereof, said axes, said base links being biased toward definite 

actuator links being pivotally connected toget.her :rn normal positions, a pair of actuator lin!~s pivotalby a pivot pin which occupies a definite neutral ly connected to said base linlrn at points spaced 

position when both of said base linlrn are in tbeir f.rom the said fixed axes thereof, said Rctuator 

normal positions and which moves in one direc·· links being pivotally connected together by a pivot 

tion from said neutral position upon oscillation pin which occupies a definite neutral position 

of one of said base links and in the opposite direc- 'Hi when both of said base links are in their said 

tion from said neutral position upon oscil!ati•ci1 normal positions, means for oscillating a first of 

of the other of said base links, and a plurality said base links through a prescribed angle from 

of motors positioned along said base links at its normal position to thereby move said pivot 

difl."erent distances from said fixed axes, each of pin to a definite ftrst position in one direction 

said motors being arranged, upon energization, '

10 from its said neutral position, and means for 

to oscillate its associated base link from its nor- pivotally moving the second of said base links 

maJ position by an amount dependent on the through a prescribed angle from its normal posidistance of such motor from the fixed axis of said tion to thereby move said pivot pin to a definite 

associated base link, whereby upon selective ene1·- .<:econd position in the opposite direction from its 

gization of such motors said pivot pin may be 45 neutral position. 

selectively moved to prescribed positions en either· 8. Mechanism for selectively moving a pivot 

side of its said neutral position. pin to any of a plurality of prescribed positions 

5. Mechanism for selectively moving a pivot on either side of an intermediate neutral position 

pin to any of a plurality of prescribecl positions comprising a pair of base linK:s which are indeon either side of an intermediate neutral position, 50 pendently oscillatable about fixed axes, stop 

eomprising a pair of base links which arc inde- means against which said base links may abut to 

pendently oscillatable about fixed axes, stop define definite normal positions for said base means which determine definite normal positions links, a pair of actuator links pivotally connected 

for said base links, which normal positions are to said base links at points spaced from the said 

generally parallel, means for biasing saict base 5;; fixed axes thereof, said actuator links being pivotlinks toward said stop means, a pair of actuator ally connected together by a pivot pin which oclinks pivotally connected to said base links at cupies a definite neutral position when both of 

points spaced from the said axes thereof, said said base links are in their said normal positions, 

flctuator links being angularly disposed relative means for pivotally moving a first of said base 

to each other and being pivotally connected to- 60 Jinks from its normal position to thereby move 

;,:;ether by a pivot pin which occupies a definite said pivot pin in one direction from its said neuneutral position when both of said base links are tral position, means for returning said first base 

i;1 their normal positions and which moves i.n one link to its normal position to thereby return 

(1irection from said neutral position upon oscilla- said pivot pin to its neutral position, means for 

tion of one of said base links and in the cpposi.te 05 pivotally moving the second of said base links 

clirection of said neutral position upon oscillation from its normal position to thereby move said 

of the other of said base links, and a plurality of pivot pin in the opposite direction from its said 

oscillatory motors positioned along said base neutral position, and means for returning said 

links at different distances from said fixed axes, second base link to its normal position to thereby 

each of said motors being arranged, upon energi- 70 again return said pivot pin to its neutral posization, to oscillate its associated base link from tion. 

its normal position by an amount dependent on the distance of such motor from the fixed axis of No references cited. 
',\ 

l 

REF ID:A4161579 

Nov. ·t 0, J 953 ,J, -£). DURKEE 

P.R:ur,n:NG TELEGRAPH SYSTEM_ 

Ori~tn'l Filed J~n. ~3. 1950 

~ ,.. 

7 ~ ~--- ~ ~ 

rl t)'~ 

~ 

~ ~ 

2,658,943 

3 Sheets-Sheet l 

~ 
REF ID:A4161579 

Nov. 10, 1953 J. D. DURKEE 

PRINTING ~ELEGRAPH SYSTEM 

Original filed Jan. 23, 1950 

:11 ~-3 

/a ....,,.,.;;...-i ..__ ....... __ _, 

k --fJ----<;~e;i;i 

2,658,943 

3 Sheets-Sheet 2 

./40· 

·' . - INVENTOR. 

i,a~ 1) .. '1)~'14ZI BY V )1 

~ fi~­ c__;- A7roR:V£~_ f 
REF ID:A4161579 

Nov. 10, 1953 J. D. DURKEE 

PRINTING TELEGRAPH.SYSTEM 

Original filed Jan. 23, 1950 

2,658,943 

3 Sheets-Sheet 3 
REF ID:A4161579 

Patented Nov. 10, 1953 2 658 nAJ3 ' ,:v"JJ: 

UNITED STATES PATENT OFFICE 

2,658,943 

PRINTING TELEGRAPH SYSTEM 

James D. Dul'kee, Fairlington, Va., assignor, by 

direct and mesne assignments, to Dualex Corporation, a corporation of Delaware 

Original application January 23, 1950, Serial No. 

139,977, now Patent No. 2,613,267, dated Oc- · tober 7, 1952. Divided and this application May 

28, 1951, Serial No. 228,657 

14 Claims. (Cl. 178-23) 

1 

My invention relates broadly to printing telegraph systems and more particulal'lY to a high 

speed polarized system of printing telegraphy 

utilizing printing telegraph apparatus of compact 

size and light weight. 

This application is a division of my application Serial Number 139,977, filed January 23, 1950, 

now U. S. Patent No. 2,613,267, dated October 7, 

1952, for Printing Telegraph System. 

One of the objects of my invention is to provide a printing telegraph system constituting an improvement upon conventional sequentially operated systems, overcoming inherent difficulties 

in these systems and to supplement the purpose 

for which the system described in my co-pending 

application No. 109,648, filed August 11, 1949, for 

Printing Telegraph System was developed. 

My co-pending application is directed to a printing telegraph system, which when applied 

to space radio systems, overcomes conditions of 

fading, interference, and static, and is particularly adaptable to mobile radio printer operations 

where compactness and portability and a mini- mum of mechanical equipment with incidental 

maintenance are major requirements. 

The system of my invention employs a polarized 

electrical matrix which reauires the transmission 

Of only five polarized pulses, Without the necessity 

of transmitting start-stop or synchronizing pulses, 

to accomplish the thirty-two different permutations and combinations of signal impulses presently used in printing telegraph systems. 

Since in my application a smaller number of 

permutations and combinations of signal pulses 

are required to produce the same number of permutations and combinations as used in currently existing systems, a greater number of permu,tations and combinations can be sent in less time 

with fewer impulses thereby requiring a smaller 

number of transmission bands and less frequency 

band-width. 

In addition, since the system of my invention 

requires only a reversal of current direction or 

polarity, the transition from one polarity or phase 

to the opposite polarity or phase may be accomplished by sinusoidal wave form; thus, the impact 

excitation resulting from a rapid make or break 

keying operation or from a rapid frequency shift 

is eliminated, thereby further decreasing the keying band-width required at any speed of tra:i;iscission. 

A further object of my invention is to provide 

a self-synchronizing receiving system which may 

be made operable over a fairly wide range ; of 

transmission speeds and which requires a minimum of equipment or adjustment. 

2 

Another object of my invention is to provide means for supplying a pulse or pulses which may 

have been lost in transmission or obliterated by 

interference and means for indicating on the re- Ii ceiving copy a mark or symbol which visually 

indicates that the character received is incorrect. 

The apparatus described in this application is 

intended for use with the printing mechanism of 

my co-pending application No. 109,648 supra but 

l O may be used with an electric typewriter or with 

slight modification of the present printing telegraph systems may be used interchangeably with 

conventional equipment. 

My invention will be more fully understood 

15 from the specifications hereinafter following by 

reference to the accompanying drawings in which 

Figure 1 diagrammatically shows the transmission system of my invention; Fig. 2 is a schematic 

plan view of a fragmentary portion of the trans20 mission keyboard; Fig. 3 is a schematic end elevational view of the transmission keyboard, the view 

being taken on sectional line 3-3 of Fig. 2 and 

showing the frame structure in vertical section; 

Fig. 4 shows the receiving circuit of the printing 

25 telegraph system of my invention; Figs. 5 and 6 

are detail views illustrating the operation of the 

control mechanism in the receiving apparatus; 

Figs. 7 and 8 are detailed views of the operating 

solenoids controlled by the printing telegraph re30 ceiving system; Figs. 9 and 10 are enlarged schematic views showing the operation of the error indicating means employed in the receiving system of my invention, the views being shown in 

front elevation and wherein Fig. 9 shows the error 

35 indicating means in printing position whereas 

Fig. 10 shows the error indicating means released 

and free of printing position; and Fig. 11 is an end view of the error indicating means shown in 

Fig. 9. 

40 Almost from the beginning of the art of printing telegraph systems efforts have been made to 

accomplish the selection of characters by electrical resolution of the units of the Baudot code. 

Each solution required the use of a large num45 ber of electrical contacts and electro-magnetic 

relays in simultaneous operation with the resulting presence of a multiplicity of potential 

error producing elements. Practical experience 

indicated that greater reliability could be placed 

50 on mechanical resolution and the present state 

of the art reflects this experience. Mechanical 

operations, however, have the inherent characteristic of requiring a longer time to perform the 

same functions than does electrical energy. 

55 However, operational communication requirements for increased speeds of operation have 
REF ID:A4161579 

2,658,943 

3 4 

at opposite ends in frame 146 of the transmitting keyboard as shown at la and l!Ji; Ba and Sb; 

9a and 9b; IOa and I Ob; and I la and I lb through 

resilient self restoring flexing strip members 

now exceeded the capabilities of the mechanical 

equipment except under strained and abnormal 

conditions which require excessive maintenance 

and mechanical tolerances and precision of apparatus which are difficult to achieve. 

The application of printing telegraph systems 

to radio communication also introduced additional difficulties which do not readily lend themselves to solution by mechanical methods due to 

the speed limitations of mechanical operations. 

5 1a'-'lb'; 8a'-8b'; 9a'-9b'; 10a'-10b'; and 

I la'-1 lb'. Contacts 12-21 are insulatingly supported in relation to frame 146 in alignment with 

the pivoted levers 7-11 as shown. The levers 7-11 

are normally biased by the resilient self restorTwo of the major difficulties· introduced by 

radio communication are various forms of fading 

and interference in addition to the basic limitation in the number of cycles available .in the 

total radio frequency spectrUm. 

10 ing .flexing strip ·members 1a'-1b'; 8a'-8b'; 

9a'-9b'; Hla'-IOb'; and I la'-1 lb', to a position in horizontal planes and flex under the pressure of the bars 2-5 in either a clockwise or a counterclockwise direction depending on the rela15 tive .positions of the bars 2-6 with respect to the 

centers bf 'levers 7-11, for effecting momentary 

contact at 12-2 I. When pressure of bars 2-6 

on the 1evers 7-11 is removed the levers 7-11 

Heretofore, various approaches to the radio applications of printer systems have been by .increasing power of transmission and improving re- ceiving conditions in an effort to duplicate the 

operating reliability of a land line to overcome 20 

fading and increasing the dot cycles of operation 

are restored to horizontal position breaking the 

contacts 'I 2--'2 I 'by the self restoring action of the 

flexing supports at each end of the levers 7-'1 I. 

The contacts which are formed depend upon 

which side of the center of levers 1 to I ·I, the bars 

2 to 6 are positioned. In the position illustrated 

by additional fail safe impulses or increasing the 

units of the basic five unit code to provide error detection resulting from interference ·and certain 

forms of fading. 

The approach of my invention to the solution 

of the requirement for increased speeds has been 

25 in Fig. 1 lever l will contact 12, lever 8 will con- tact 15, lever 9 will contact 16, lever 10 will con- tact 19, and lever 11 will contact 2il, placing alto eliminate the basic mechanical limitation of ternatively positi\'e and negative currents from 

the mechanism used to resolve the units of the 

five unit code into characters by use of a polarized 30 

electrical matrix; to decrease the electrical con- tacts required to a minimum by use .of rectifying 

apparatus and the application of new and novel 

electrical circuits and to decrease the operational 

functions to a minimum 'by simplification of 35 

equipment and electrical circuits. 

The fading and interference problems in'troduced by radio communication have been accepted as natural characteristics of the medium. Circuits and operations are provided by my inven- 40 

tion which take these natural characteristics into 

account and provide substitute characteristics in 

the form of locally produced impulses to replace 

those lost in transmission due to fading or to 

counter baiance impulses introduced in trans- 45 

mission as a result of interference and to indicate on the receiving equipment when these functions have been required to complete the formation of a character. 

In endeavoring to achieve grea.ter economy of 50 

bandwidth, the start-step or synchronizing im-

.pulses heretofore used in both radio and wire 

methods have been eliminated in my invention by 

self-synchronizing apparatus resulting in an approximate saving of twenty per cent of bandwith 55 

required to perform the functions necessary to 

the formation of a character as compared to systems which transmit start-stop impulses or synchronizing impulses. 

source of battery 29 on stepping relay contacts 22, 

23, 24, 25 and 26 arranged in the path of switch arm 27 of continuously cycling driven stepping 

relay 28. 

When this contact was made a positive cur- rent flow took place from battery 29 <Fig. l') 

contact through 12, and the contact carried by 

lever 1 to stepping relay contact 22 through arm 27 through relay coil 30 to the center tap 29a 

of battery 29. The current in coil 30 caused 

armature 31 to move down, making contact with 

contact 32 which in turn caused the armature 

33 of stepping relay 28 to be moved down because of the current in relay coil 34 produced 

by closing of contact 32. The movement of ar- mature 33 caused ratchet arm 35 to pull arm 27 away from contact ·22 counterclockwise towards stepping relay contact 23. During the 

time the arm 21 was in contact with contact 

·22. a positive voltage was applied to line 3G with 

respect to ground or center tap 29a of ·battery 

29, or was caused to flow through rectifier U 

through relay coil 38a in a positive direction ·re- sulting in movement of arm 39 of relay 40 to 

make contact at 43 which in turn keyed the 

marking frequency of a frequency shift radio 

printer keying circuit. 

As soon as arm 2l left contact 22 the current 

in relay coil 30 was released and contacts 31 

and 32 were opened de-energizing coil 34 of the 

continuously cycling spring driven stepping re- lay. 28 which in turn repositioned ratchet arm 35 preparatory for another ratcheting operation. 

My invention employs .apparatus and methods 60 

which are compatible with existing methods and 

apparatus, allowing in almost every instance, the 

use, with slight modification, bf existing equipment and methods to accomplish its purpose. 

The capacity 41 and adjustable resistor 42 

across coil 34 acts to retard the arm 27, sufficiently long at each contact '22 to 2'6 to permit 

65 the full cycle of operation previously described 

to be completed. Transmitting apparatus 

Figs. 1, 2 and 3 show the transmission system of 

my invention, the transmitting ·keyboard being 

shown in plan view in Fig. 2 and in end view in 

Fig. 3. 

When the key I, pivotally mounted at I a, is 

depressed, bars 2, 3, 4, a and 6 which extend 

therefrom depress levers l, '8, 9, HJ and 11 in a ·downward direction to form :contact with the 

contacts l 2 to 21. The levers l-1) ·.are suppo,r~ed 

When ·arm 27 arrived at contact 23 the same cycle of operation was set in motion as when 

the arm 21 was at contact 22, except that the 

70 charge of voltage on contact 23 is now derived 

from the negative source of ·battery 29, thru 

the contact on lever 8 and contact 15 and a negative charge was placed, thru rectifier 31 and 

relay coil 31a to ground or center tap 29a of bat75 tery 29, causing armature 39 to close contacts 
REF ID:A4161579 

a,eGB,943 

5 

44 keying the spacing frequency of the frequency shift keying system or causing a negative charge ta be placed on line 36. 

The same cycle of operation is repeated at 

stepping relay contacts 24, 25 and 26 resulting 5 in moving arm 21 back to the original position 

in contact with contact 22 having thus com- pleted a transmission cycle of fcur self-cycling 

operations from contact 22 to contact 26 which 

resulted in sending four equally spaced pulses 10 and one starting pulse of alternate positive and 

negative charges to a line or causing the two 

frequencies of a frequency shift keying system 

to be alternatively operated causing five pulses 

divided between two different alternating cur- 15 

rents to be transmitted. 

Since the pulse caused to be transmitted when arm 27 is in contact with contact 22, is the starting pulse, it does not have to be especially spaced 

in relation to any previous pulse. The pulse 20 created by contact of arm 21 with contact 26 

is the end of the character forming combination. 

Figs. 2 and 3 show the arrangement of the 

transmission keyboard more clearly from which 25 the coaction Of the pivoted keylevers 45 with the 

contact control means will be understood. The 

key-levers are arranged above the angularly 

shiftable levers 1, 8, 9, IO and 11 and through 

bars 2, 3, 4, 5 and 6 selectively control the an- 30 gular movement of the levers about their pivots 

Ta, lb-Ila, llb, that in turn control the con- tacts 12, 13, 14, 15, 16, 11, 18, 19, 20 and 21,.for 

controlling the circuits heretofore described. 

When arm 21 arrives at contact 26, current 35 from negative battery 29 ftows through coill 46, arm 21 and can 30 to the center tap 29a of battery 29. This causes armature 41 to be attracted by the electro-magnetic core of coil 46 making contact at 49, permitting current to flow 40 through coil 49 from positive battery 29 to negative battery 29. When coil 49 shown more clearly in Fig. 3 was energized armature 50 was drawn towards the electro-magnetic core of :the 

coil 49 pushing oscillating bar 50' against jar- o±ii 

mature 51 releasing pressure of point 51 a; of 

pivoted member 51 on roller 52 carried by .the 

end of keylever 45 permitting spring 53 to pull 

keylever 45 up against stop 54 which ac~ion 

lifted key bars 2, 3, 4, 5 and 6 from bars 1., 8, 50 9, I 0 and 11, allowing the latter to resume :qormal position. Thus permutations and combinations of signal pulses can be formed and 

transmitted by contacts 43 and 44 under selective control of the keyboard as described. 55 Had it been desired to utilize the keying mechanism in the manner described in my co-pending application No. 109,648 supra for simulta- neous transmission of a coded character, the 

oscillators 4Da, 40b, 40c, 40d and 4De of the cir- 60 cuit of Fig. 1 of that application would be connected to contacts 13, 15, 11, 19 and 21, and 

levers 1, B, 9, IO and 11 would be connected together and returned to contact with 40/. Contacts 13, 15, 11, 19 and 21 would have been dis- 65 connected and levers 1, 8, 9, I 0 and 11, when 

in normal position, would have been making 

contact with contacts 12, 14, 16, 18 and 20 

causing oscillators 40a, 40b, 40c, 40d and 4De 

to continuously generate alternating current 70 

tones into the line 36 or an amplifier as described in my aforesaid co-pending application. 

When key I is depressed contact is broken at 

contacts 1, 12, at 9, 14 and at 11,20, causing 

oscillators 40a, 40c and 40e to be removed from 75 

6 

the line and the character which is made up 

of signals from oscillators 40b and 40d in simultaneous combination would be formed. 

Receiving apparatus 

Fig. 4 shows the receiving circuit for the re- ceiving printer of my invention. I provide a "pyramid" or "Christmas tree" arrangement of 

relays 63, 97, I 03, and 110, in series with a rectifier circuit, and having associated armatures 

18, 98, I 04, and 111, respectively, arranged to 

control permutations and combinations of signal pulses through associated contacts and circuits connected therewith. An unlatching or fifth relay I 16 is used for controlling an arma- ture 117 for unlatching armatures 18, 98, I 04 

and I l I for enabling the system to receive the 

next succeeding signal impulse group. The permutation and combination incoming signal 

pulses, whether received by line or as a result 

of rectification of a radio or audio frequency 

current, appears on line 141 of Fig. 4 as a positive or negative voltage with respect to ground 

55 in accordance with the manner in which it was transmitted by the apparatus described in 

Figs. 1-3. The current flows through the stepping arm 61 of cycling switch 62 to contact 56 

and the winding of relay 63 and, if the voltage is 

of positive polarity with respect to 55, which is 

the center tap 29a of battery 29 from which the 

voltage on line 141 is derived, through rectifier 

64 to line 55. The current also flows through coil 

65 from line 141 to line 55. 

When current passed through coil 65, armature GS made connection with contact 61 com- pleting the circuit between positive battery 29 

and coil 68 and ground 55. This moved armature 

ll!l to the left causing ratchet arm 10 to tmn 

ratchet wheel 71, which caused arm 61 to move from contact 56 to contact 57, and through shaft 

145 caused arm 12 to move from open contact 

13 to contact 14. 

When armature 66 moves to the left under con- trol of coil 65, armature 66 makes connection 

with contact 67. An extension rod 66a interconnects armature 66 with the operating spring 

66b and draws operating spring 66b to the left 

whereby the continuity of the circuit 141 to arm GI is broken between spring 66b and spring G6c, 

insuring against the possibility of a prolonged 

pulse causing a false operation prior to the com- pletion of the pulse duty cycle. This also permits 

the carrier or signal current to be maintained in an on condition during the interim between the 

formation of signal characters. 

When current is pa::;sed through relay 63, arma- ture 18 causes extension bar ·19 to pull contacts 

80 to Bl into connection with contacts 89, 90, 91, 

92, 93, 94, 95 and 96. 

Upon arrival of arm 61 at contact 51 the circuit from line 141 through rectifier 64 to line 

55 is completed. If the voltage on line 141 is now negative, rectifier 64 will not pass current 

through relay coil 91 to ground 55 and thus armature 98 remains in position shown and contacts to 

I 02 are not broken. 

The current through coil 65 again causes the 

arm 61, as a result of the action similar to 

that previously described, to move to contact 58. 

If the voltage in line 141 is now positive with 

respect to ground or center tap 29a of battery 29 

and the circuit is completed from line 14 l through arm 61, contact 58, coil I 03, to rectifier G4, and 

line 55, the current ftow through coil I 03, causes armature I 04 to move bar I 05 causing leaf spring 
REF ID:A4161579 

1 8 

contacts ·I 06 aJJ.d ·14l·l to1eOI1llect .with'contaots UIB . To overcome .this condition, ,.provision has been 

and ,109. ma.de in the selector ,system for .the .supplying 

When ·arm .6:1 arrives at ·contact .58 .t~ ooti0n of lost impulses ·and recording this circumstance 

resulting from current action in coil 65 is again on the printed copy. .The ·effect of interference 

repeated causing arm 5·1 to ·move to contact 59 () is ·made to ·appear as a •lost impulse in this system. 

and .arm 32 :of the stepping sW:itch ·.62 to .move :Es.ch ·time .that the armature 66 .is in contact 

to contact l6. with .contact .124 in addition to holding armature 

The arrival of arm ;51 at teontact :59 ·completes 125 in .contact with contact 126, battery 29 C+.) 

the circuit ·from line 141 · thn0ugh ·coil .I :1'0, a1•m charges the condenser resistor .delay network 121 

61 contact 59, to rectifier 164. If 1the voltage "is 10 and .128 across coil -129. Each time the armature now negative, Tectifier 164 will not pass current 66 is •opened .by ·removal of :energy from coil 65., 

through ·coil 110 ·to ·ground 55 :and armaiture lil<I contacts 66 and .124 are :broken which .opens the 

and bar 1 ·12 remain in ·,the :position shown. cixcuit from .positive battery 2 9 to negative bat-

.The current in .coil 55 present ·when ·contact tery .29 ·through ,coil J 29. When .this .occurs :the 

62 •of .arm BJ js .in •contact with contact .59 .causes 15 energy .stored .in capacitor In ·starts discharging arm 51 to move to1contact·G.D :and !arm l2 ;to move through resistors 128 and t2Ba:int0 .coil .129 holdto contact :ll. iilg ,armature 126 .that .is in circuit with -con- Line ii 4 l is :now connected thru ann '.6;1. :cont1wt denser ,130 .through contact 1.2 6 .to -battery 29. 

60 :and contacts 11.3, :1.Dl, .1:09, ID I, 85 :a.nd :94, li ,no voltage ·appears ·on line .14'1 for a fixed 

to the .printer magnets N ·and SP., :to rectifiers 20 per.iod :of-.time :after.contact has been established 

11:4 and '115 to line 55 thrnugh lead :55a. by arm <6~ -with ;any one of-the-con.tacts -51, .so, 59 

1f ·the voltage in line ;l'4'J -~vas .positive when and r60 :befo11e :the dissipation .of energy in .con- contact was·made1by arm:S•I at contact·60, a.posi- denser 121 is complete, armature 125 will ,be 

tive current will now pass through the .printer released .f.rom .contact i1:26 .and .contact will :be 

magnets N CFig. 4) .and rectifier .u 5 to :and .by 25 established w.it!J, •contact 1.3·1 allowing condenser 

the process ,described above. This will cause 1.a.o to ·discharge 1through ·resistor l,30a, coil 1.32, 

the:letter N•of the·printer to print. arm l2 :and ·contact~•. '1·5, 16 ·or ll .of ·a duplicate 

When 1the :lettet :N .function ·was activated by bank 1of :contacts ·on the :same :shaft as •Contact 

the action of arm •6:1 contacting ·contact c60, .cur- arm •6·1 to :line •1.(1,7 through whichever circuit 

rent •also passed .through relay ,coil MS in the ao arm 16:1 provides through its contact with con- lead :55a ·which .caused .armature :In to unlatch tacts ·56 ·,to 60, ,thus :PI"Oducin,g the same .action 

armatures '18, ·94, I 04 :and •111 1of relays .63, 91, which ·would ,have resulted ;from an incoming 

I 03 and 11 0 preparing .the :system to :receive a signal on line 14 l. new cycle of .character forming impulses. When ithis current ·passed .through coil ·132 the 

Examination of.Fig. 4 will:sho:w that, predicat- 35 armatw·e .133 was :moved ·and closed .the .circuit 

ed upon the polarity of currents :·in .'line 14:7 ·witl1 through -contact tS3a connecting -battery 29 to 

respect to line :55 .as presented .to .the '"pyramid" a rela·Y 1134 associated .with .the printing mecha- or "Christmas '.tree" :shown in ·the lower .right, nism. 

hand portion of Fig. 4 in :sequential •combination ·w11en the relay :134 .was energized, the arma- and with the use of pressure rnller ·springs :HS, 40 ture 4.35 ·was :attracted to ithe pole of 1coil 134, 

:U9, '120 and 121 to ·latch armature llll, 98, :104 latching 'itself to latching ·armature 136 and 

and 111 in a fixed position for a period covering bl'inging the extension ·;wire 131 :of al'mature rl35 

the cycle of operation, .it:is possible·toindi·vidua1ly •across the•surface·.of .the ·character A ·for example 

select any one of the multiplicity .of 1magnets ..in on the ".type pallet .1.38 which may ,strike the :ink 

various permutations ·and combinations repre- .

45 ribbon ·1:39 .of 'Fig .. 11 and be printed•on the ipaper 

sented by reference "Let" designating "letters" web 1.40 :being :advanced on :platen 141 of the 

.to "Blk" .designating "blank" ;of Fig. 1. In .Figs. :printer as ·shown more clearly in .Figs. 9 and .10, 

5 and 6 I 'have shown the .two limiting positions :and 1'1. .Pig. :9 shows the condition for indicating 

of armature l H on an enlarged ·scale to :'illustrate er.ror ·while Fig. 10 ·shows an .all 1clear condition 

.the two extreme latched positions ·thereof .under 150 .with the 1error 'indicator removed. 

control of p11essure roller ·spring 1:18 .. All :of the ·when relay ·1t6 ·was ene11g·ized contact was armatures '18, 98, 1!04 .are arranged ..in a .manner made 1between :1'44 and l;l l, ·placing battery ·.on oSimilar .to armature 1!1 l, thatis .the armatur.e JB, ·Coil 142 which caused .armature :136 to .release 

'96 and .1 !Vi :are .controlled :in 1their limiting :posi- ·armature t35 allowing spring .1:43 to draw :arma- tions by pressure itoller ;springs J2:l, rl 20 :and ·1:19 ili5 ture 135 to its ·norma:l position .with the ·extenrespectively. ·sion rl 3.l :clear of the printing :Sur.face ·of 1the~next 

Figs. 7 and 8 are .enlarged :views •of the sole- ·character ·,placed ·in ;a 'Printing ·position . 

. noids in the polarized "pyramid" or ·"Christmas · :When the letter key 'is operated .to ;print the 

tree" circuit wherein Fig. 7 .represents the 'juxta- ·-Chamcter .farmed, piutly by the ·self-;imposed impositions of the differentially polarized .;0perating 160 ·pulses •Of :condenser ,f30, the .character which is 

.solenoids for letters W and A and lletters Z and ·printed .will "be ·marked ibY .a ·ver,tical ·bar ·stroke 

E while Fig. 8 shows the electrical equivalent ·of 1by :the •extension .bar J3l .of armature 135 plainly 

the same juxtapositioned ·solenoids. ·indicating to .the .operator ·.that the character 

'The capacitor~resistor combination 1:22 :and was ·not :properly ·receiv.ed. 

123, are used to control .the dissipation of :cur- :65 The ··rotary selecting printing .mechanism :dirent in condenser 122 through teoil .as after 1open- 'Scribed in :my co-pending application No. 109;648 

ing ·Of the circuit to .battery 29 :c+) :by ·the oper- .supra •may 1be ·used in connection :with :the apation of relay 65 and which in turn .controls ·the ·paratus :described in this :application to 1select 

length ·Of time in which arm :&·I moves from one and print the characters and perform the other 

·contact to the other of -the .group ,of •contacts 56 :7.0 •operations ·required of ·a .printing mechanism. 

to :60. This may be :accomplished 1by connecting the 

Under certain conditions -of operation particu- contacts ·of the rotary switch :and .the "letters," 

lady in radio circuits the possibility .of loss 1of "''figures" and ·'1space" .:relays :to the contacts .rep-

·one ·Or more impulses .due .to .fading ·or oblitera- Tesented iby ,the solenoids for 1letters :K, W, ·etc. 

,tion ·of signals ·by interference ·is always present. :T'6 •Of :Fig .. 4. 
REF ID:A4161579 

2,658,943 

.9 10 

It wm be fully understood that these same _selectively excitable by· current pulses accordcontaqts of Fig. 4 can be conneded.·to a series ing to the polarity thereof. 

of solenoids or magnets and be used to operate 6. ·A printing telegraph system as set forth an electric typewriter or initiate the printing in claim· 2 which also includes an auxiliary cirmechanism of other types of presently used print- Ci cuit selectively excitable under conditions of 

ing telegraph equipment. failure of receipt of all of the current pulses 

Conventional printer mechanism is operated constituting a signal permutation or combinaby the solenoids "letters" through "blank" shown tion. 

in the polarized "pyramid" or "Christmas tree" 7. A printing telegraph system as set forth 

in the lower left corner of Fig. 4. 10 in claim 2 which also includes an auxiliary cirDue to the fact that the necessity for a me- · cuit operative upon failure of any one of the 

chanical selector is eliminated in the printer signal permutations or combinations and means 

system of my invention and yet very accurate for restoring said auxiliary circuit to normal 

and quick movement of the selection system of condition after correction of the failed permumy invention obtained by use of pQsitive and I 5 tation ·or combination. 

negative electrical impulses; I am able to reduce 8. A printing telegraph system as set forth 

the' size and weight of the equipment, as com- in claim 2 which includes a circuit containing 

pared to conventional equipment, very material- an electrostatic ·capacity wherein said electroly. static capacity accumulates an electrical charge 

While I have described my invention in cer- 20 · upon the incomplete rer;eipt of a code signal pertain of its preferred embodiments I realize that mutation or combination, an electrical circuit 

modifications may be made and I desire that it controlled by said electrostatic capacity, a relay 

be understood that no limitations upon my in- controlled by said electrical circuit, and means 

vention are intended other than may be imposed for restoring said relay to normal condition after 

by the scope of the appended claims. 25 dissipation of the electrostatic charge in said 

What I claim as new and desire to secure by electrostatic capacity. 

Letters Patent of the United States is as follows: 9. A printing telegraph system as set forth 

1. In a printing telegraph system, a plurality in claim 2 in which said differentially polarized 

of pairs of printer operating solenoids each in- printer solenoids are arranged in pairs by a 

eluding differentially polarized individual sole- 30 connection bonding adjacent ends of the windnoids, a polarized pyramid circuit, selective con- ings of said solenoids and wherein the opposite 

ditioning means for controlling said pola1·ized ends of each winding are connected in series 

pyramid circuit for selectively exciting tha in- with separate rectifiers which are polarized to 

dividual printer solenoids of said pairs of printer pass current through one of said solenoijs in 

operating solenoids by positive or negative cur- 35 one direction and to pass current through the 

rent ptilses, H signal input circuit, a stepping other solenoid in the opposite direction. 

switch including an arm ooerative over a multi- 10. A printing telegraph system as set forth 

p!icity of contactors, control relays individual in claim 1 in which unidirectionally current canto the said contactors, and means in said signal ducting devices are electrically connected in 

input circuit for selectively operating said step- 40 series with the individual solenoids of each of 

pin<r switch relative to signal pulses for selec- said pairs of printer operating solenoids for setively exciting certain of said relays, and means lectively supplying operating current to said 

operated by said relays for controlling said po- printer operating solenoids unilaterally accordlarized pyramid circuit. ing to the operation of said polarized pyramid 

2. In a printing telegraph system, a circuit for 45 circuit. 

receiving positive and negative signal current 11. A printing telegraph system as set forth in 

pulses, a step-by-step switch controlled by said claim 1 in which there are at least fonr of said 

pulses, contactors individual to the step-by-step control relays e<=tch having an operating armapositions of said switch, relays selectively ex- ture for controlling the operation of said polarcited by currents from circuits extending from 50 ized pyramid circuit and wherein a fifth relav is 

said contactors, a polarized pyramid circuit in- connected in series with said polarized pyramid 

eluding sets of. make and break movable con- circuit and is provided with an armature oner- tactors with associated conta.cts, means oper- ative after each printing operation to restore 

ated by said relays for controlling the displace- the :umatures of the aforesaid control relays to 

ment of said make and break movable contactors 55 positions preparatory for receiving signal imwith respect to the associated contacts, and dif- pulses representing a succeeding character. 

ferentially polarized printer solenoids arranged 12. A printing telegraph system as set forth In 

in pairs and connected with the contacts in said ·claim 1 in which there are at least four of said 

polarized pyramid circuit and selectively aper- control relays each havinz an operating arma- ative by positive and negative current pulses for 60 ture for controlling the operation of said polarselectively operating printer mechanism. ized pyramid circuit, the windings of said control 

3. A printing telegraph system as set forth relays all being connected with said signal input 

In claim 2 including means for latching said circuit through a rectifier for sμpplying unidimovable contactors in selectively displaced po- rectional operating pulses to said windings and 

sitlons. 65 wherein a fifth relay is connected in series with 

4. A printing telegraph system as set forth said polarized pyramid circuit and is provided 

in claim 2, including means for simultaneously with an armature aligned with -respect to all 

restoring said movable contactors in said polar- of the armatures of said control relays and opized pyramid circuit to the original positions erative after each printing operation to restore 

thereof from their displaced positions. 70 all of the aforesaid armatures to positions prep5. A printing telegraph system as set forth aratory for receiving signal impulses representin claim 2 in which said differentially polarized ing a succeeding character. 

printer solenoids are selectively conn-3cted 13. A printing telegraph system as set forth In 

through unidirectional current feed circuits claim 1 in which the means in said signal input 

whereby the individual solenoids of each pair are 75 circuit for selectively operating said stepping 
REF ID:A4161579 

2,658,948 

ll 1'2. 

switch comprise a pair of: relays,. one of. said 

relays: havtng its: winding connected in. said signal input, circuit an.Li operating an armature for 

controlling· a. multiplicity of leaf Slll'ings an~ as.- sociated· contacts; the other. of said relays having 

disposed: in the circuits. of said' telegraph system one. of said rectifier.a beihg connected ill selies 

between said signal: input cfrcuit. .and safd' con- trol relays and the other of safd rectffl'ers being 

5 connected In series with said: solenoids in saili 

pyramid circuit, said last mentioned' rectifiers 

befu.g electrically reversed' V<i.th respect to each 

other whereby current trows unidirectiOnally lh 

said pyramid circuit. in opposite directions, acits winding connected in series, with one: of the 

aforesaid leaf springs and associated contacts 

and having an armature ratcheting the arm of 

said stepping switch, certain of the. lea! springs 

and·. contacts, of said aforementioned ·rela:'l forming a circuit, path for signal impulses through 

said stepping switch and one: of the leaf springs 

and associated contacts of the aforementioned 

relay forming a circuit path through said last 

mentioned. relay· for effecting a. stepping opera- 15 

tion. of said. stepping, switch according to tae reception of the· signal pulses and a. rectifier disposed in circuit with said arm. for. restricting the 

current flow therethroughi to unidirectional 

pulses. 

14 .. A printing telegraph. system as set forth in 

claim 1 in which three, independent rectifiers. are 

10 cording. to. the permutatibns and· combinations 

of the signaf pulses. 

JAMES D. DURKEE·. 

References Cited in. the file . of this patent· 

tJNITED, STATES. FA'l'ENTS 

Ntun!Jer 

80,t,173' 

970,367 

20 2',2l'Z,l!61 

2;37:5;588 

2;52.0,1!42: 

Name Date: 

Barclay· ---------- Oct., a~. 1905 

Blas ------------- Sept. 13, 1.9'IO 

IDoty _______ .:.__ __ Oct .. a1, 1940 

Rose: ------------- May 8,. Ir945 

Heirbst -----------· Aug. 2:9',. 1:950 

,._I 

'r 
REF ID:A4161579 

Oct. 7, 1952 J. D. DURKEE 

PRINTING TELEGRAPH SYSTEM 

Filed Jan. 23, 1950 

~ 

~ 

\ 

~ ill 

I 

~ 

Fl 

~-----.111111• •l•l•I tj 

+ ~ 111..------+-~IJ) C\J . ru 

2,613,267 

.3 Sheets-Sheet 1 

~ , 

/ 

// 

~ I 

~ 

~ ~ ~ ~ 

lj~' ~ 

o~ ~ ~ 9' 

" 
Oct. 7, 1952 

Filed Jan. 23, 1950 

REF ID:A4161579 

J. D. DURKEE 

PRINTING TELEGRAPH SYSTEM 

2,613,267 

3 Sheets-Sheet 2 

::ll~-3 

/a ,...,,.,,;;,,__j ...... ...,.___,,,_~ 

k--tt~~Ct;,i 

I 

_,/J18 

I 

! 

I 

--nu-_10 

I 

./.40 

, -INVENTOR. 

1>a~ ')) .. 'l'M.da4,, BY lJ · ) 

. ~ !.<?uu•C . AT'TO~~E~Y-7 
Oct. 7, 1952 

Filed Jan. 23, 1950 

REF ID:A4161579 

J. D. DURKEE 

PRINTING TELEGRAPH SYSTEM 

2,613,267 

3 Sheets-Sheet 3 
REF ID:A4161579 

Patented Oct. 7, 1952 2 613 267 

' ' 

UNITED STATES PATENT OFFICE 

2,613,267 

PRINTING TELEGRAPH SYSTEM 

James D. Durkee, FalrUngton, Va. 

Application Januar;y 23, 1950, Serial No. 139,977 

5 Claims. (Cl. 178-23) 

1 

My invention relates broadly to printing: telegraph systems and more particularly to a high 

speed polarized system of printing telegraphy 

utilizing printing telegraph apparatus of compact 

size and light weight. 5 

One of the objects of my invention is to provide a printing telegraph system constituting an improvement upon conventional sequentially operated systems, overcoming inherent difficulties 

in these systems. 10 

This invention covers a printing telegraph apparatus and system which Is self-synchronizfog, 

requires less channel band-width than existing 

methods, provides means for indicating when 

impulses are lost or obliterated by fading or 15 

Interference and Is capable of increased transmission speeds and yet employs less equipment even when adapted to equipment and systems 

presently in use. 

This achievement is made possible by the in- 20 

vention of a polarized electrical matrix which re- quires the transmission of only five polarized 

pulses, without the necessity of transmitting 

start-stop or synchronizing pulses, to accomplish 

the thirty-two different permutations and com- 25 

binations of signal impulses presently used in 

printing telegraph systems. ' 

Since in my application a smaller number of 

permutations and combinations of signal pulses are required to produce the same number of 30 

permutations and combinations as used in cur- rently existing systems, a greater number of 

permutations and combinations can be sent in 

less time with fewer impulses thereby requiring a smaller number of transmission bauds and less 35 

frequency band-width. 

In addition, since the system of my invention 

requires only a reversal of current direction or polarity, the transition from one polarity or phase 

to the opposite polarity or phase may be accom- 40 

plished by sinusoidal wave form; thus, the impact 

excitation resulting from a rapid make or break 

keying operation or from a rapid frequency shift 

is eliminated, thereby further decreasing the keying band-width required at any speed of trans- 45 

mission. 

A further object of my invention is to provide a self-synchronizing receiving system which may 

be made -0perable over a fairly wide range of 

transmission speeds and which requires a mini- 50 

mum -0f equipment or adjustment. 

Another object of my invention is to provide means for supplying a pulse or pulses which may 

have been lost in transmission or obliterated by 

interference and means for indicating on the 55 

2 

receiving copy a mark or symbol which visually 

indicates that the character received is incorrect. 

The apparatus described in this application Is 

intended for use with an electric typewriter or with slight modification of the present printing 

telegraph systems may be used interchangeably 

with conventional equipment. 

My invention will be more fully understood 

from the specifications hereinafter following by 

reference to the accompanying drawings in which 

Figure 1 diagrammatically shows the transmission system of my invention; Fig. 2 is a schematic 

plan view of a fragmentary portion of the transmission keyboard; Fig. 3 is a schematic and elevational view of the transmission keyboard, the 

view being taken on sectional line 3-3 of Fig. 2 

and showing the frame structure in vertical sec- tion; Fig. 4 shows the receiving circuit of the 

printing telegraph system of my invention; Figs. 

5 and 6 are detail views illustrating the operation of the control mechanism in the receiving 

apparatus; Figs. 7 and 8 are detailed views of 

the operating solenoids controlled by the printing telegraph receiving system; Figs. 9 and 10 

are enlarged schema tic views showing the operation of the error indicating means employed 

in the receiving system of my invention, the views 

being shown in front elevation and wherein Fig. 

9 shows the error indicating means in printing 

position whereas Fig. 10 shows the error indicating means released and free of printing position; 

and Fig. 11 is an end view of the error indicating means shown in Fig. 9. 

Almost from the beginning of the art of printing telegraph systems efforts have been made to 

accomplish the selection of characters by electrical resolution of the units of the Baudot code. 

Each solution required the use of a large number 

of electrical contacts and electro-magnetic re- lays in simultaneous operation with the resulting presence of a multiplicity of potential error producing elements. Practical experience indicated that greater reliability could be placed on 

mechanical resolution and the present state of 

the art reflects this experience. Mechanical operations, however, have the inherent characteristic of requiring a longer time to perform the 

same functions than does electrical energy. 

However, operational communication requirements for increased speeds of operation have 

now exceeded the capabilities of the mechanical 

equipment except under strained and abnormal 

conditions which require excessive maintenance 

and mechanical tolerances and precision of apparatus which are difficult to achieve. 
REF ID:A4161579 

. C'· .- ~ ;-.~ 

,-: 

3 

2,818,287 

4 

The application of printing telegraph systems I la'-1 lb'. Contacts 12-21 are insulatingly supto radio communication also introduced addi- ported in relation to frame 146 in alignment with 

tional difficulties which do not readily lend the pivoted levers l-1 l as shown. The levers 

themselves to solution by mechanical methods l-11 are normally biased by the resilient self 

due to the speed limitations of mechanical 5 restoring flexing strip members la'-lb'; 

operations. 8a'-8b'; 9a'-9b'; IOa'-IOb'; and 1 la'-1 lb', 

Two of the major difficulties introduced by to a position in horizontal planes and flex under 

radio communication are various forms of fading the pressure of the bars 2-6 in either a clockwise 

and interference in addition to the basic limita- or a counter-clockwise direction depending on tion in the n'uinber·or: cycles available· in the total 10 the relative positfoiis of the bars 2....'.6 with respect 

radio frequency spectrum. to the centers of levers· l-11, 'for effecting 

Heretofore, various approaches to the radio momentary contact at 12-2 I. When pressure of 

applications of printer systems have been by"· bars 2-6 on the levers l-11 is removed the levers 

increasing power of transmission and improv- l-11 are restored to horizontal position breaking 

ing receiving conditions in an effort to· duplicate 15 the contacts 12:....21 by the self restoring action of 

the operating reliability of a land -line to over- the flexing supports at each end of the levers come fading and increasing .the dot cycles of. l-11. The contacts which are formed depend 

operation by additional fail safe' impulses or in- upon· which side of the center of levers l to 11, 

creasing the units of the basic five unit code to · ·: ithe bar·s 2 to 6 are positioned. In the position 

provide error detection re8ulting from interfer- 20 illustrated in Fig. 1 lever l will contact 12, lever ence and certain forms of fading. 8 will contact 15, lever 9 will contact 16, lever 11 

The approach of my invention to the solution will contact 19, and lever 11 will contact 20, placof the- requirement for increased speeds has been ing alternatively positive and negative currents 

to eliminate the basic mechanical limitation of from source of battery ~9 on stepping relay con-. the mechanism used to resolve the units. of the 25 tacts 22, 23, 24, 25 and· 26 arranged in the path .. five unit code into characters by use of a· polar- of switch arm 2l of continuously cycling driven 

ized electrical matrix; to decrease ·the electrical stepping relay 28. 

contacts required to a minimum by use of recti- When· this contact was made a positive cur,. .. fying apparatus and the application of new and rent flow took place from battery 29 <Fig. 1> con..,. 

novel electrical circuits and to decrease the 30 tact through 12, and the contact carried by lever. 

operational functions to a minimum by simpli- 1 to stepping relay contact 22 through arni 2l 

fication of equipm.ent and electrical circuits. through relay coil 30 to .the center tap 29a of , '.!'he fading and interference problems intro- battery 29. The current in coil 30 caused arm·a..,' 

duced by radio communication have been ac- ture 31 to move down, making contact with con-. cepted as natural characteristics of the medium. 35 tact 32 which in turn caused the armature 33 

Circuits and operations are provided by my in- of stepping relay. 28 to be moved down because 

vention which take these-natural characteristics of .the current in relay coil 34 produced by clos-. 

into accourit and provide ·substitute character- ing of contact 32. The movement of armature 

istics in the form of locally produced impulses to 33 caused ratchet arm 35 to pull arm 2l away 

replace those lost in transmission due to fading 40 from contact 22 counterclockwise towards step- or .to .counterbalance - itnpulses introduced in ping relay contact 23. During the time the arm transmission as a result of interference and to 2'i was in contact with contact 22, a positive volt-. 

indicate on the receiving equipment when these age was applied to line 36 with respect to ground · functions have been required to complete the or center tap 29a of battery 29, or wa·s caused to : 

formation of a character. :flow through rectifier 38 through relay coil 38a 

In 'endeavoring to . achieve greater ·economy 

45 in a positive direction resulting in movement of 

of bandwidth, the start-stop or synchronizing arm' 39 of relay 40 to make contact at 43 which 

impulses heretofpre used in both radio and wire in turn keyed the marking. frequency of a. fremethods have been eliminated in my invention by quency shift radio printer keying circuit. 

self-synchronizing apparatus resulting in an ap- As soon as arm 2l left. contact 22 ihe current 

proximate saving of twenty per cent of band- 50 in relay coil 30 was released and contacts 31 anci. 

width required to perform the functions neces- 32 were opened de-energizing coil 34 of the cori- ·. sary to the formation of a character as compared .tinuously cycl.fug spring driven stepping relay 28 

to systems which transmit start-stop impulses or which in turn repositioned ratchet arm 35 prepar- synchronizing impulses. My invention employs apparatus and methods 55 .atory for another ratcheting operation. 

which are compatible with existing methods and The capacity 41 and adjustabie resistor 42 

apparatus, allowing in almost every ·instance, the across coil 34 acts to retard the arm 2l, suffiuse, with slight modification, or existing equip- ciently long at each contact 22 ·to 26 to permit the 

ment"and methods to accomplish its purpose. full cycle of operation previously described to be 

60 completed. 

Transmitting apparatus When arm 2l arrived at contact· 23 the same 

Figs. 1, 2 and 3 show the transmission system cycle of operation was· set in motion- as when the 

of my invention, the transmitting keyboard being arm 2l was at contact 22, except that the charge ._ shown in plan view in Fig. 2 and in end view in . of voltage on contact 23 is now derived from 

Fig. 3. 65. the negative source Of battery 29." thru the con- · 

When the ·key I, pivotally mounted at la, is tact on lever 8 and contact 15 and a negative-· 

depressed, bars 2, 3, 4, 5 and 6 which extend charge was placed, thru rectifier 3l and relay 

therefrom depress levers l, 8, 9, 10 and 11 in a coil 3la to ground or center tap 29a of battery. 

downward direction to form contact ·with the 29, causing armature 39 to close contacts 44_ keycontacts 12 to 21. ·The levers l-11 are supported 70 ing the spacing frequency of the frequency shift~ 

at opposite ends in frame 146 of the transmitting keYing system or causing a negative. charge .to be 

keyboard as shown at la and lb; Ba and Sb; placed on line 36. 

9a and 9b; IOa and I Ob; and I la and I lb through The same cycle ·of operation is repeated at . resilient self ·restoring :flexing strip members stepping relay contacts 24, 25 and 26 result,ng 

1a'-1b'; 8.a'-8b'; 9a',-9b~; IOa'-IOb'; and 76 in mo:ving arm 21 back to.the original PQsition: 
REF ID:A4161579 

2,613,267 

5 

fn cqntact with contact 22 having thus completed 

6 

When armature 86 made connection with con- tact 61, extension rod 66a connected with aper. 

ating spring 66b the continuity of the circuit 141 

to arm 61 was broken between spring 68b and 

contact 66c, insuring against the possibility of· a prolonged pulse causing a false operation prior 

to the completion of the pulse duty cycle. This 

also permits the carrier or signal current to be 

maintained in an "on" condition during the ina transmission cycle of four self-cycling operations from contact 22 to contact 26 which re- sulted in sending four equally spaced pulses and one starting pulse of alternate positive and nega- 5 

tive charges to a line or causing the two frequencies of a frequency shift keying system to be 

alternatively operated causing five pulses divided 

between two different alternating currents to be 

transmitted. 10 terim between the formation of signal characters. 

Since the pulse caused to be transmitted when arm 21 is in contact with contact 22, is the starting pulse, it does not have to be especially spaced 

in relation to any previous pulse. The pulse cre- ated by contact of arm 21 with contact 26 is the 15 

end of the character forming combination. 

Figs. 2 and 3 show the arrangement of the 

transmission keyboard more clearly from which 

the coaction of the pivoted keylevers 45 with the 

contact control means wm be understood. The 20 

key~levers are arranged above the angularly shiftable levers l, 8, 9, I 0 and 11 and through bars 

2, 3, 4, 5 and 6 selectively control the angular 

movement of the levers about their pivots la, 

'lb-I la, I lb, that in turn control the contact 2;; 

12, 13, 14, 15, 18, 11, 18, 19, 20 and 21 for controlling the circuits heretofore described. 

When arm 21 arrives at contact 26, current 

from negative battery 29 flows through coil 48, arm 21 and coll 30 to the center tap 29a of bat- :io 

tery 29. This causes armature 41 to be attracted 

When current was passed through relay 63, 

armature 78 caused extension bar 19 to pull con- tacts 80 to Ol into connection with contacts 89, 

90, 91, 92, 93, 94, 95 and 96. 

Upon arrival of arm 61 at contact 51 the circuit from l!ne 141 through rectifier 64 to line.55 

is completed. If the voltage Qil line I 4l is now negative, rectifier G4 will not pass current 

through relay coll 97 to ground 55 and thus ar- mature 98 remains in position shown and con- tacts to I !!2 are not broken. 

The current through coil 65 again caused the_ arm 61, as a result of the action similar to, that 

previously described, to move to contact 58. If 

the voltage in line 141 is now positive with re- spect to ground or center tap 29a of battery 29 

and the circuit is completed from line 147 

through arm GI, contact 58, coll I 03, to rect!fier 

34, and line 5~. the current fl.ow through coil I 03, 

caused armature 104 to move bar 105 causing leaf 

spring contacts I OS and I Ol to connect with contacts I OB and I 09. 

When arm 61 arrived at contact 58 the action 

resulting from current action in coll 65 was again 

repeated causing 61 to mo.ve to contact 59 and arm 32 of the stepping switch 62 to move to con- tact 16. 

The anival of arm 61 at contact 59 completed 

the circuit from line 14l through coil 110, arm S l contact 59, to rectifiers 64. If _the voltage is now negative, rectifier 64 will not pass current 

through co.il I I 0 to ground 55 and armature I I I 

and bar 112 remain in the position shown. 

The current in coll 65 present when contact 62 

of arm 6 I is in contact with contact 59 caused arm 51 to move to contact 60 and arm 12 to move 

to contact 11. 

by the electro-magnetic core of coll 46 making 

contact at 48, permitting current to flow through 

coll 49 from positive battery 29 to negative battery 29. When coll 49 shown more clearly in Fig. 35 

3 was energized armature 50 was drawn towards 

the electro-magnetic core of the coll 49 pushing 

osc!llating bar 60' against armature 51 releasing 

pressure of point 51 a of pivoted member 51 on roller 52 carried by the end of keylever 45 per- 40 

mitting spring 53 to pull keylever 45 up against 

stop 54 which action lifted key bars 2, 3, 4, 5 

and 6 from bars l, 8, 9, 10 and 11, allowing the 

latter to resume normal position. Thus permutations and combinations of signal pulses can be 45 

formed and transmitted by contacts 43 and 44 

under selective control of the keyboard as described. Line 14 l is now connected thru arm 61, contact 

60 and contacts 113, I 01, I 09, I 0 I, 85 and 94, to 

50 the printer magnets N and SP, to rectifiers 114 

and I i 5 to line 55 through lead 55a. 

Receiving apparatus 

Fig. 4 shows the receiving circuit for the re- ceiving printer of my invention. The permutation and combination incoming signal pulses, 

whether received by line or as a result of rec- tification of a radio or audio frequency cur- rent, appears on line 141 of Fig. 4 as a positive or negative voltage with respect to ground 55 in 

accordance with the manner in which it was transmitted by the apparatus described in Figs. 

1-3. The current flows through the stepping arm Bl of. cycling switch 82 to contact 56 and the 

winding of relay 63 and, if the \'Oltage is of positive polarity with respect to 55, which is the cen- ter tap 29a of battery 29 from which the voltage on line 141 Is derived, through a rectifier 64 

If the voltage in line 141 was positive when 

contact was made by arm 61 at contact 60, a positive current will now pass through the printer 

:;:; magnets N (Fig. 4) and rectifier 115 to and by the 

process described above. This will ca.use the letter N of the printer to print. 

When the letter N function was activated by 

the action of arm GI contacting contact 60, cur- GO rent also passed through relay coil 1 l 6 in the lead 

55a which caused armature 11 l to unlatch arma- tures 18, 94, 104 and 111 of relays 63, 91, 103 and 

11 O preparing the system to receive a new cycle 

of character forming impulses. 

to line 65. The current also flows through coil 6·' 

85 from line 141 to l!ne 55. 

Examination of Fig. 4 w111 show that, predicated upon the polarity of the currents in line 

147 with respect tQ line 55 as presented to the 

matrix shown in the lower right hand portion of 

Fig. 4 in sequential combination and with the use 

When current passed through coll 65, armature 

66 made connection with contact 61 completing 

the circuit between positive battery 29 and coil 68 

and ground 55. This moved armature 69 to the 

left causing ratchet arm 10 to turn ratchet wheel 

11, which caused arm 61 to move from contact 

68 to contact 51, and through shaft 145 caused 

arm 12 to move from open contact 13 to contact 14. 

70 of pressure roller springs 118, 119, 120 and 121 

to latch armature 78, 98, I 04 and 111 in a fixed 

position for a period covering the cycle of operation, it is possible to individually select any one of 

the multiplicity of magnets in various permuta75 tions and combinations represented by reference 
REF ID:A4161579 

1''·· "Let~· .designatilig .... Letters"· to 1

'Bik'1 designating 

"Blank"rof:Fig::4; Irt Figs. 5 and 6.I have· shown 

the two ·limiting positions of armature 111 on an enlargea ·scale· to illustrate ·the· two ·extreme 

latched·ipositions thereo.f under control of pres- 5 

sure' roller spring 118. All of the armatures 18; 

98,' I 04 are arranged in a manner similar to arma- ture 111, that is the armatures 78, 98 ·and I 04 are controlled in their limiting positions by pressure 

roller' springs ·121, 120 and 119 respectively. IO 

Figs. 7 and 8 are enlarged views of the solenoids 

in the i>olarized matrix •circuit wherein Fig. 7 

represents the juxtapositions of the operating 

SQlenoids for letters W and A and letters Z and 

E while Fig. 8 shows the electrical equivalent of 15 

the :sanie juxtapositioned solenoids. 

The ·capacitor-resistor combination 122 and 

123, are used to control the- dissipation of current 

in condenser 122 through coil 68 after opening 

of the circuit to battery 29 <+> by the operation 20 

of relay 65 and which in turn controls the length 

of time in which arm 61 moves from one contact 

to the other of the graup of contacts 56 to 60. 

Under certain conditions of operation particularly in radio circuits the possibility of loss of 25 one or more impulses due to fading or o.bliteration 

of signals by interference is always present. 

To overcome this condition, provision has been 

made in the selector system for the supplying of 

lost impulses and recording this circumstance o,ll :io 

the printed copy. The effect of interference is 

made to appear as a lost impulse in this system. · 

Each time that the armature 66 is in contact 

with contact ·124 in addition to holding armature 

125 in contact with contact 126, battery 29 < +) 35 

charges the condenser resistor delay network 127 

and 128 across coil 129. Each time the armature 

8 

while Fig. 10 shows an· a.u~·c1ear conditfon'.witho 

the error indicator removed.· : ··::-:·c:: · 

When · relay I 16 · wa·s energized contact' was·· 

made between 144 and 11 l, placing battel:y oD: 

coil 142 which caused armature 136 to release .·· armature 135 allowirtg spring 143 to draw arina-·. 

ture 135 to its· normal position with the extension~· 

137 clear of the printing surface of the next char-' 

acter placed in a printing position. ·' ~ · > 

When the latter key is operated to print '.the 

character formed, partly by the self-imposed impulses of condenser 130, the character which is 

printed will be marked by a vertical bar stroke· 

by the extension bar 137 of armature 135 plainly'. 

indicating to the operator that the character wllB 

not properiy received. 

Rotary selecting printing mechanism may be 

used in connection with the apparatus described 

in this application to select and print the characters and perform the other operations reqwred 

of a printing mechanism. This may be• accom- plished by connecting the. contacts Of the rotary 

switch and the "Letteri;;,'' "Figures" and "Space"· 

relays to the contacts represented by the solenoids for letters K, w, etc. of Fig. 4. · 

It Will be fully understood that these same con- tacts of Fig. 4 can be connected to a series of solenoids or magnets and be used to operate an electric typewriter or initiate the printing mechanism of other types of presentlY used printing telegraph equipment. · · · · 

Conventional printer mechanism is operated by' 

the solenoids letters through blank shown iil the· 

polarized matrix in the lower left corner of Fig. 2. 

66' is o.pened by. removal of energy from coil 65, 

contacts 66 and 124 are broken which opens the 

circuit from positive. battery 29 to negative bat- 40 

tery 29 through coil 129. When this occurs the 

energy stored in capacitor 121 starts discharging 

through resistors 128 and f28a into co.il I 29 

holding armature 125 that is in circuit with condenser 130 through contact 1'26 to battery 29. 

If no voltage appears on line 147 for a fixed 

period of time after contact has been established 

Due to the fact that the necessity" for a me-'· · 

chahical sel~ctor is eliminated in the printer sys-. .. tern of my invention and yet very accurate and'' 

quick movement of the selection system of my invention obtained by use of positive and negative· 

electrical impulses, I am able to reduce the size 

and weight of the equipment, as compared to ·. conv~ntional. equipment, very materially. · 

The receiver and transmitter with wliich the 

system of ·the .insta~t illvention operates· are set · 

45 forth in my 'copending applications for Letters · 

Patent Serial Numbers 228,657 .and 228,658, both 

filed May 28, i951. · · 

by arm 61 with any one of the contacts 57, 58, 59 

and 60 befQre the dissipation of energy in condenser 121 is complete, armature. I 25 will be re- 50 

leased from contact I 26 and contact will be established with contact 131 allowing condenser 130 

to discharge'through resistor 13Da, coil 132, arm 

72 and contact 74, 75, 76 or 11 or'a duplicate barik 

of contacts on.the same shaft as contact arm 61 55 

ta line 147 · thrnugh which ever circuit arm 61 

provides through its contact with contacts 56 

While I have described my invention in certain ... 

of its preferred embodiments I realize that modifications may be made and I desire that it be un- derstood that no limitations upon my invention are intended other t_han may be imposed by the 

scope of the appended claims. . 

What I ciailn as new and desire to secure by 

Letters Patent of the United States is as follows:· 

to 60, thus producing the same action which 

would· have resulted from an incoming signal on 

11Iie ·141: _ . 

L In a printing, telegraph system, a type bar· 

printer including at the printing position thereof . a platen for supporting and advancing the printer, 

copy, a printing ribbon aligned with said platen. 

60 at the instance of striking of the ·printer copy by 

a type bar, an error indicator device movablerinto· 

the p~th of impact of the type bar with the print_,.:, 

ing ribbon and the printer copy for indicating · failure of receipt of the required signal code im- . 

pulse perml!tations and combinations for effect- · ing the selection and printing of the intended: 

When this current passed through coil 132 the 

armature 133 was moved and closed the circuit 

through contact 133a connecting battery 29 to a 

relay 1.34 associated with the printing mechanism. 65 When the relay 134 was energized, the armature 

135 was attracted to. the pole of coil 134, latching 

itself to-latching armature 136 and bringing the 

extension wire 137 of ai:mature ,-35 across the surface of the character A for example on the type. 70 

pallet I 38 which may strike the ink ribbon 139 

of Fig. 11 and be printed on the paper web 140 

being advanced on ·platen 141 of the printer as shown:more, clearly. in Figs. 9 and 10, and 11. 

Fig; 9. shows the ·condition· for indicating· error 715 

character. 

2. A printing telegraph ·system as set. forth in 

claim 1 in· which the error indicator device is 

electromagnetically actuated by failure of receipt 

of the required signal code impulse permutations and combinations. · 

3. A ·printing telegraph system as set forth in:· 

claim 1 in which·the error indicator device is elec-·::; 

tromagnetically positioned in the path of impact:,.' 
REF ID:A4161579 

2,613,267 

9 

of the type bar upon failure of receipt of the re- quired signal code impulse permutations and com- binations and in which an additional electromagnetic device is located adjacent the error indicator device for restoring said indicator device to 5 

non-alignment with the impact path of the type 

bar when the required signal code permutation 

and combination for the particular character in error is corrected. 

4. A printing telegraph system comprising in 10 

combination with a type bar printer including at 

the printing position thereof a platen for supporting and advancing the printer copy, inking means aligned with the platen at the instance of 

striking of the printer copy by the type bar and 15 means for interposing an error indicator in the 

path of an actuated type bar, said inking means and said printer copy so long as incomplete sig-'· 

nal code impulse permutations and combinations are received. : ' 20 

5. A printing telegraph system as set forth ,in 

10 

claim 4 in which means are provided for remov- ing the error indicator from the path of an ac- tuated type bar, said platen and the printer copy 

concurrently with the restoration of the complete 

signal code impulse permutation and combination 

for the character intended. 

JAMES D. DURKEE. 

REFERENCES CITED 

The following references are of record in the 

file of this patent: 

UNITED STATES PATENTS 

Number 

1,737,024 

2,304,120 

2,353,327 

2,471,473 

2,498,695 

2,516,936 

Name Date 

Roe --------------- Nov. 26, 1929 

Potts --------------- Dec. 8, 1942 

VVarwick __________ July 11, 1944 

Young ----------'-- May 31, 1949 

McVVhirter ________ Feb. 28, 1950 

Young -----------.-- Aug. 1, 1950 
-' 

Patented Mar. 5, 1946 2- 3· 95 g· 5·3' ' ' . 

UNITED STATES PAtENT 

2,395,863 

CRYPTOGRAPIDC DEVICE 

William F. Friedman, Washington, D: c, 

Application October 19, 1939, Serial No. 300,2i2 

19 Claims. (.CI.- 35-2) 

(Granted under the act of' March 3, i8S3, as 

amended April 30, 1928; 370 0. G. 757) 

OFFICE 

The invention described herein may be manu- it re·sts upon a table, desk; or other plane surfaee. 

factured and used by or for the Government for Or, if the operator prefers to lay the device flat 

governmental purposes, without the payment to upon the table; the i;ubber feet 11, at the four me of any royalty thereon. corners of the bottom of· base I will support the 

This invention relates to cryptographic devices 5 device and keep it from sliding about on the 

and has for its object the provision of a hand- table. 

operated device capable of affording a relatively As stated atiove, irifo the channel ways 3 tnere 

high degree of security without involving the use are inserted character strips 4 of paper or oth.e'r 

of complicated mechanisms. suitable material, hereinafter called alphabet 

Another object is to provide a device useful in IO strips, upon which appear sequences of letters of 

cryptographic and cryptanalytic investigations the alphabet, each sequence being repeated on requiring the use of sliding alphabets. the strip, and the letters .being .equidistant from 

The invention is· described with reference to one another throughout. The purpose of the 

the accompanying drawings, in which: · duplication of sequence will appear presently. 

Fig. 1 is a perspective showing one form or em- 15 The letters on the alphabet strips may be in nor- bodiment of the invention; mal order or in disarranged order; if the· latter, 

Fig. 2 is a top plan view of another embodiment the various alphaoets may or may not be difof the invention; · ferent. Assuming; however, different alphabets 

Fig. 3 is a cross-section taken on the line 3-3 are being used, each' strip bears an identifying 

of Fig. 2; :io mark such as a number 14, so that the alphabet 

Fig. 3a is a fragment of the same section on an strips may be inserted into the channel ways 3 

enlarged scale showing the T-grip for the guide according to some preagreed key. For example, 

rule in operative.position; in Fig. 1 is shown a set of twenty-five channel · Fig. 4 is a top view of the form of invention of ways· into which twenty-five different alphabet 

Fig. i showing the guide rule in shifted position; 25 strips· 4 have been inserted according to the fol- . Fig. 5 is a top plan view showing another em- lowing key, reading from' the top downward: 

bodiment of the invention in which the base is 14 16 _9_5_22_25-23-5~12.=.... 4~13;,_:!f.:..._ 

composed o{ separate detachable. grooved· sec- IB-'-l"'-'-f=ll-=-20.:::...·1 9-'-15.:.._8..:.._·11....:..2.;......_3..:.._10-4 tions; 

Fig: 6' is a J)erspective showing one o( the 30 If another embodiment of the device should ingrooved· sections; and elude more than twenty-five channel ways, addiFig. 'i is a perspective showing a frame structure tional alphabet strips may be·inserted, according 

ancf sub-base on which said grooved sections may to a longer key. 

be assembled. . Having inserted the alphabet strips into the 

Referring to Fig. l, in this embodiment the de- 35 channel ways in· key order, the device is now ready 

vice comprises a base I, on which are horizontally for use either to encipher a plain language mes- fastened a series of cylindrical rods 2, forming a sage or to decipher a· cryptogram which has.been 

set of channel ways-3, into which character bear- ~nciphered by means of the device, alphabets, and 

ing strips 4', may be inserted and slid from: left key shown·in Fig: 1. Suppose this plain-text mes- to light or vice versa. In the specific embodiment 40 sage is to be enciphered: 

disclosed hereirr the device comprises twenty-five ACCORDING TO AN OF.FicIAL"REPORT 

such channel ways, but the device is by no means FROM MILITARY AUTHORITIEl~l 

limited to this number. The number chosen in 

this embodiment is merely a convenient num'ber, Moving the reading gμide 5 to the left, and 

and it may be increased or decreased within cer- 45. oringing it against the left end bar 8, the operator 

fain limits in other embodiments \Vithout ma- proceeds to align; in a column· immediately to 

terially departing from the spirit of the invention. the right of the reading guide, the first twentyA rule, or reading g-qide. 5,. attached to a reading five letters of the· message, This is' most convenguide slide 6, can be slid to the left or right on a iently done by placing· the eraser end of a pencil 

reading guide slide rail' r End bars B and- 9, 50 upon the successive desired letters as found on 

serve as stops against which the reading guide t:J:ie successive alphabet strips 4 from the top 

5 may be brought at the end· of its travel to ,the downwards, and pulling or pushing the alphabet 

left or right. To the back of the base I is fas- strips in their channel ways toward the reading 

tened a hinged support Io: which can be pulled guide, so, that each strip stops' w'itl1 the proper 

out· to supp'ort tlie'. deviCe iri a·slantii:lg position as 55 letter just, to tp,e right" of the right-hand edge of 
'· 

2 2,395,863 

the reading guide 5. When the alphabet strips are being aligned on the left-hand side of the 

device as in the above procedure, the operator confin~s his search' for letters to the left-hand 

half of the duplicated sequence on each alphabet 

strip. 

When all twenty-five alphabet strips have been 

aligned as indicated, there is disclosed a multiplicity of columns of letters to the right of the 

plain-text column of letters thus aligned. All 

these columns of letters, except one, are col- umns of cipher letters, each column representing a cipher equivalent of the plain-text column. 

The single exception is the column which is the 

twenty-fifth removed from the plain-text column 

set up by the operator, and is merely a repetition of that plain-text column. One of these 

cipher columns is selected at random and is 

recorded in five-letter groups. The reading guide 

5 is useful in this operation, since by placing it 

alongside the column selected, reading of the 

cipher column is facilitated. Suppose that the 

reading guide 5 be moved. so that its left-hand 

edge aligns a column of cipher text. AB shown 

in Fig. 4, such a column would read as follows: 

SNAFJ LXRJG GVWVA ATVWW PVNUT 

These letters are recorded and constitute the 

cipher letters for the twenty-five plain-text letters. 

The reading guide 5 is now moved to the titreme right of the device, up against the right 

end bar 9; the next twenty-five letters of the 

plain text are aligned against the left edge of the 

reading guide 5. Again a set of columns of 

cipher letters are disclosed to the left of the 

reading guide.. One of these columns is selected 

at random and again a set of twenty-five cipher 

letters representing the second set of twentyfive plain-text letters is recorded. If the mes- sage contains more than fifty letters, the foregoing procedure is repeated until the entire mes- sage has been enciphered. There is no need to 

indicate to the recipient of the message which 

column is selected for the cipher equivalent of 

each set of twenty-five plain-text letters, as will 

be noted presently. 

To decipher the message, having the alphabets 

and the key according to which they have been 

arranged, the operator merely proceeds as in -encipherment, aligning the alphabet strips in 

their channel ways so that the first twenty-five 

cipher letters of the cryptogram are in one column. He then examines all the other twentyfive columns of letters, looking for one which 

contains intelligible text throughout its extent 

from top to bottom. There will be one and only one such column, and this will be the plaintext equivalent of the column of cipher text 

set up on the device. The reading guide 5 is 

useful in this search for the plain-text column, r..s 

it can readly be moved to scan the successive col- . umns from left to right, or from right to left. 

The plain-text column thus found is recorded 

in word lengths and the operator proceeds to -~et 

up the next twenty-five cipher letters on the 

right-hand side of the device. Again he looks -for a plain-text column and records it when 

found. He continues this process until the mes- sage has been completely deciphered. 

In the form of invention sho'\\'Il in Fig. 2, the . device comprises a pair of hinged components 

F-F' of metal, Bakelite or other suitable material and foldable on one another in the manner 

of a book. As here shown, the grooved slideways 3 are formed on the inner faces of the said 

components by milling, or in the case where a condensation product such as Bakelite is used, 

may be molded in the material. In the embodi5 ment disclosed, there are a total of thirty such 

slideways, fifteen in each com~onent, though it . will be understood that the invention is not limited to any particular number. It will be noted 

that the slideways are open at their opposite ends 

10 so that the alphabet strips may be readily inserted and freely extended outwardly therefrom as they are slid into different positions in the 

operations of enciphering and deciphering. As 

in other forms of the invention, a T-grip 6 is at15 taehed to the guide rule 5 at its end .for the purpose of manipulating the rule, and is slidable in a channel 20 having therein undercut grooves 21 

and 22 formed laterally along its inside edges. 

The grip 6 is provided with a spring-pressed ele20 ment 23 engaging in bottom groove 21, and having an oppositely disposed bead 24 engaging in 

the opposite groove 22 whereby the grip 6 is 

maintained under suitable sliding tension in the 

channel 23, and whereby the guide rule 5 is 

:.!Ii manipulated transversely in relation to the alphabet strips 4; and the opposite end of the rule 

is adapted to slide freely in a lateral undercut 

groove 25 formed in component F'. The grip 6 

is rigidly secured to the guide rule 5 in the man- 30 ner of a T-square and may be so manipulated 

that the rule affords a positive means of obtaining an accurate alignment in column formation 

of the characters on said alphabet strips and in 

varying· relations for cryptographic purposes. 

3u This foldable form of device presents a number of 

practical advantages, among which may be men- tioned its compactness· and portability; also the 

foldable feature permits exclusion of dust and 

dirt. 

40 While in one form of device here disclosed, cy- . lindrical rods are secured to a base at regular 

intervals from one another to form the channel 

ways into which the alphabet strips are inserted, 

it should be understood that any other means -15 may be employed to form the channel ways. 

For example, a series of elongated metal strips 

known in the trade as "card holders," used 

ordinarily to hold narrow strips of paper bearing names of mail-box owners in apartment houses, 

50 etc., may be used to form the channel ways; 

these card holders "may be riveted to the base, 

or spot welded to it, or attached in any other 

suitable manner. Or as disclosed in connection 

with Fig. 2, the channel ways may be formed 

55 by milling grooves in the base I itself, which 

may be made of molded Bakelite, for example .. In such case the grooves are made by a rotating cutter which undercuts· at the two edges, 

forming a channel way such as is commonly 

llO found in slide-rules. Figure 6 shows such a section in the form of a piece of B:lkelite or similar 

material 13, in which five such channel ways 3 

have been cut. Sections with equal or unequal 

numbers of channel ways may be easily provided 

ll5 and given .identifying symbols such as letters, 

A, B, C, ... 

In Fig. 7 there is shown a sub-base suitable for use with such sections of channel ways. Thus, 

instead of having all the channel ways on a single 

70 base, as is the case in Fig. 1, the sub-base is 

merely made in the form of a fiat surface onto 

which sections of channel ways may be positioned 

and temporarily fixed, so that rearrangements of 

sections can be made according to subsidiary keys. 

75 Referring to Fig. 7, the sub-base la is a. plane 
•. 

' - • 

.a,S9l>/863 

-stir.face ·which is ·.provided. with an .undercut slot 

14, for carrying a sliding clamp 1.5, provided with a knm:led:thumb screw 16, for fastening the clamp 

:into -position. End bars 8 and 9 elevated above 

the base by supports 1 l and back stop I B, serve 

the same purpose as similarly designated end -bars 

of ·Fig. 1. 

.Using a sub~base such as that shown in Fig. 7, 

with several sections such as that shown in Fig. 6, 

.bearing thereon alphabetic character . sequences 

·and !ndividuany·movable in said ways;:anct·means 

adjustable 'transversely of .said strips .to .facilitate 

the reading of. said'charaGters.in varying:relations 

5 ·for .enciphering and deciphering messages. 

.5, A cr.yptographic device comprising a base 

·haVing vertically grooved slide-ways formed 

ther-ein; strips bearing thereon alphabetic character sequences and individually .slidable in said 

lO ways; and means adjustable transversely of said 

·strips for facilitating the .reading .of said characters in varying relations for .enciphering and 

deciphering :messages. 

· one method of operation of this embodiment of 

the invention is shown in Fig. 5. In· that figure 

there are five sections of 3, 4, 5, ·7 and 8 channel 

ways, giving a total of twenty-seven channehvays. 

First, the sections are temporarily fastened to the 

base in the alphabetical order of their identifying 

symbols. Then the twenty-seven alphabet strips 

would be inserted in the twenty-seven consecutive 

channel ways according to the predetermined 

numerical key already referred to above. in connection with Fig. 1. To encipher a given message, there would then be a subsidiary or specific 

key, also arranged for in advance by means of an 

incilcator in the message, which would direct that 

the sections be now placed onto the base in a 

mixed order, say E-D-A-B-C, as shown in 

Fig. 5. The encipherment of a message would 

then proceed exactly as before. In another message, the indicator for the sectional arrangement 

might be different, say one calling for the sequence of sections D-A-C-E-B. Thus, with 

five sections there could be 120 different arrangements of sections on the base, even though only 

one.set of alphabet strips is employed. The purpose of this is, of course, to increase the keying 

possibilities of the device, and to impart unique- 35 

ness to successive messages, without going to the 

trouble of making a complete rearrangement of 

6. A cryptographic device comprising a 'base 

.15 provided with.a plurality of channel ways; .alphabet bearing strips adapted· to be individually inserted and aligned in varying relations in said 

ways for cry.ptographic purposes; and a slidable 

guide rule for making excursions transversely 

20 along tbe channel ways and in relation to said 

strips for enciphering and deciphering messages. 

7. A cryptographic device comprising a base 

having a supporting foot hingedly attached to 

the under surface of said base; a plurality of 

25 members fixed to the obverse surface of the base 

at equidistant intervals to form a plurality of 

channel ways; strips bearing alphabetic sequences of characters individually slida-ble in said 

ways; a guide rule adapted to be moved trans30 versely of said strips to facilitate the reatj.ing of 

selected sequences of characters in varying relations for cryptographic purposes; and stop mem-

'bers for the guide rule disposed at opposite ends 

of said channel ways. 

8. A cryptographic device comprising a suhbase; interchangeable base-sections having 

;grooves formed therein to provide a plurality of 

channel ways; means for removably attaching 

·said sections in position on said sub-base to perall alphabet strips in the set of twenty-five channel ways. 

The many uses of this device, with variable 

alphabets, in crytographic or cryptanalytic studies 

will be apparent to all skilled in the art and 

nothing further need be said on this score except 

that there has existed for many years a hitherto 

unfulfilled need for a simple device of this type, 

suitable for the insertion of sliding alphabets. 

Changes, modifications and equivalent arrangements are contemplated within .the scope of the 

invention as defined by the appended claims. 

I claim: ' 

l. A cryptographic device comprising a base 

provided with a plurality of horizontal channel 

ways; strips provided with discrete sequences of 

equally spaced alphabetic characters adapted for 

insertion therein and adjustable independently of 

one another and means for facilitating the ·reading of said characters in selected columns. 

2. A cryptographic device comprising a base, 

said base being provided with a plurality of vertical channel ways, and individually adjustable 

strips bearing discrete sequences of equally spaced 

alphabetic characters adapted to be slidably inserted therein; and means for facilitating the 

reading of said characters in selected columns 

and in different relations for cryptographic purposes. 

3. A cryptographic device comprising a base 

formed with horizontally grooved slide-ways 

therein; individually adjustable alphabetic strips 

slidable in said ways; and means to facilitate the 

reading of selected alphabetic columns in varying 

relations for cryptographic purposes. 

4. A cryptographic device comprising a base 

formed with grooved slide-ways therein; strips 

40 mit different arrangements of said sections in 

juxtaposed relationship for cryptographic purposes; character bearing strips adapted for slidable insertion in said channel ways; and a slidable guide rule movable transversely across said 

43 di.annel ways and in varying relations to said 

strips for enciphering and deciphering messages. 

9. A combination according to claim 8 in which 

said grooved sections are of the same size and 

contain equal numbers of channel ways, 

60 10. A combination according to claim 8, in 

which said grooved sections are of different sizes 

and contain unequal numbers of channel ways. 

11. A combination according to claim 8 in 

which stops are provided at the opposite ends of 

115 the channel ways to limit the movement of the 

slide rule at the end of its travel. · 

12. A cryptographic device comprising a frame 

structure and including a sub-base formed therein; ·a series of base-sections having grooves 

60 therein to provide a plurality of channel ways; means for removably attaching said sections on 

said sub-base to permit different juxtaposed arrangements thereof for cryptographic purposes; 

strips bearing alphabetic sequences of characters 

65 slidable in said ways; and a slidable guide rule 

movable transversely of said strips and alignable 

in varying relations with respect to said characters for enciphering and deciphering messages. 

13. A cryptographic device comprising a frame 

70 structure and including a sub-base therein; 

base-sections grooved to provide a plurality of 

channel ways, said sections having different numbers of said channel ways and being differentiated from one another by distinguishing sym-

'lll bols; means for detachably securing said sections 

' 
-.· 

'· 

REF ID:A4161fl9 

;4 2,395,863 

on the sub-base to permit different juxtaposed 

arrangements thereof for cryptographic purposes; strips bearing alpha:betic sequences of 

characters movable in said channel ways; a guide 

rule slidable transverseiy of said strips and align- 5 

able in varying relations with said characters for 

enciphering and deciphering messages; and stop 

members at opposite ends of the channel ways to 

limit the movement of the slide rule at the end 

-acters in varying relations for enciphering and 

deciphering messages. 

17. A cryptographic device composed of hinged 

sections foldable upon one another, said sections 

being provided on their inner faees with openended slide ways; strips slidable in said ways and 

of its travel. 

14. A cryptographic device comprising a multiple base formed of separate sections, said sec- tions being interchangeable with one another to 

permit different juxtaposed arrangements for 

bearing thereon sequences of alphabetic characters; and a guide rule hinged to fold-with said 

sections, said rule being disposed transversely of 

10 said strips and movable to facilitate reading of. 

the characters in varying relations for enciphering and deciphering messages. 

18. A cryptographic device comprising a pair 

of hinged components foldable upon one another, 

said components being provided on their inner 

faces with open-ended slide ways; a guide rule 

hinged to fold with said components; means operative with one of said components to maintain . said rule in a position transversely of said strips 

-cryptographic purposes; a plurality of channel 15 

ways in said sections; strips bearing sequences of 

characters and individually slidable in said ways; 

and a guide rule movable transversely of said 

strips and alignable with said characters in varying relations for ·enciphering and deciphering 20 _and movable to ·facilitate reading of the characters in column formation and in varying relations for enciphering and deciphering messages; 

and terminal stops to limit the movements of 

_messages. 

15. A cryptographic device including a multiform ·base composed of separate sections, said sec- tions having grooved slide-ways therein and being interchangeable with one another to permit 25 different juxtaposed arrangements for cryptographic purposes; strips slidable in said ways 

and bearic.g thereon sequences of alphabetic 

characters; and - guide means disposed transversely of said strips and movable to facilitate 30 alignment of the characters in varying relations 

for enciphering and deciphering messages. 

16. A cryptographic device composed of hinged 

sections foldable upon one another, said sections 

having grooved slide-ways formed- on their inner 35 

faces; stiips slida-ble in said ways and bearing 

thereon sequences of alphabetic characters; and 

guide means disposed transversely of s~ ~rips 

and movable to facilitate alignment of th"W°<;;har- ~ -. 

' 

said rule at either end of its travel. 

19. A cryptographic· device comprising hinged 

components foldable upon one another, said com- ponents being provided on their inner faces with a plurality of slide ways; a guide rule hinged to 

fold with said components; a grooved channel 

formed along the edge of one of said components 

in parallslism with the slide ways; means including a spring-tensioned element slidable in said 

channel for operating the said rule while maintaining the same in a position transversely of 

said strips, said rule being movwble to facilitate 

reading" of the characters in varying relations and 

in column formation for enciphering and deciphering messages. - WILLIAM F. FRIEDMAN. 

( 
March 5~ 1946. 

REF ID:A4161579 

·W. F. FRIEDMAN 

CRYPTOGRAPHIC DEVICE 

2,395,863 

Filed Oct. 19, 1939 3 Sheets-Sheet 2 

- .2. 

• J UY G T & M B I/" L• D "I. r.. A. B Q 'II: P :ZR ..1 UT Ci TI t=':::' •::;•::::• "='="=' "::::'::::• •=•=• =°'="========~=l 

• B ,I I. A ' 1• 

IJ 

.. 

/ 

4- e..___, 

ic: 

8/ 

I 

8 

-~--

I 

J 11 1 

.-11111111111111111111111111 i I 

17 / 

/ 

/ 

• 

. 

l 

r 

J 

- v 

• 

p 

v 

u 

/ 

/. 

.5 

' 

' 

., 

•' '• 

•' 

•• '1 

' ' 

' 

" ZJ 

.. . 

' .. , T~ " . " . ~ 

N 

. 0 I 

• " 

' • ,,. 

"' 

. 

T R 

PIO 

O 4o 

"5 / 

J 2 7 !J 

/8 .9 - (I) 

E 

A 

r 

/ 

'/ 

..f 
REF ID :.A4161579 

March 5, 1946. W. F. FRIEDMAN 

CRYPTOGRAPHIC DEVICE 

Filed Oct. 19. 1939 

2,395,863 

3 Sheets-Sheet 1 

,,,c-,, G. /. 

- -1- - ----------- ·- - . ---- ---··· ... --- ---· ·---- - - . ·····---- -----t. 

, - ·.°'t-:- ·"'t .:.1.·t· I• I· I· ·I· I· I· I· I· I - I. I· I• I· I. I· I 

I 

... . . 

.. liiiiiil '.-~ 

rotl11111111111.t11/11,, / 

' t 2/ 
March 5, 1946. 

REF ID:A4161519 

W. F. FRIEDMAN 

CRYPTOGRAPHIC DEVICE 

Filed Oct. 19. 1939 

= 

-

r/G.7 

2,395,863. 

3 Sheets-Sheet 3 

I 
REF ID:A4161579 

) 

Patented Mar. 5, 1946 

UNITED STATES ~PATENT 

2,395,863 

CRYPTOGRAPIIlC DEVi:CE 

William F. ·Friedman, Washfogton, ·b. C. 

Application October 19, 1939, Serial No. 30il,2i2 

19 Claims. (Cl. 35-2) 

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 

2,395,86"3 

OFFICE 

The invention described herein may be manu- it rests upon a table, desk; or other plarie surface. 

factured and used by or for the Government for Or, if the operator prefers to lay the device flat 

governmental purposes, without the payment to upon the table; the rub.ber feet I I, at the four me of any royalty thereon. . corners of the bottom of base I will support the 

This invention relates to cryptographic devices 5 device and keep -it from sliding about on the 

and has for its object the provision of a hand- table. 

operated device capable of affording a relatively As stated al:icive, iritci the channel ways 3 there 

high degree of security without involving the use are inserted character strips 4 of paper or other 

of complicated mechanisms. suitable material, hereinafter called alphabet 

Another object is to provide a device useful in 10 strips, upon which appear sequences of lettel·s of 

cryptographic and cryptanalytic investigations the alphabet, each sequence being repeated on requiring the use of sliding alphabets. the strip, and the letters J:ieitJ.g equidistant from 

The invention is described with reference to. one another throughout~ The purpose of the 

the accompanying drawings, in which: duplication of sequence will appear presently. 

Fig. 1 is a perspective showing one form or em- 15 The letters cin the alphaliet strips may be in riorbodiment of the.invention; mal order or in disarranged order; if the latter, 

Fig. 2 is a top plan view of another embodiment the various alphai.Jets may or may not be difof the invention; fei·ent. Assuming, however, different alphabets 

Fig. 3 is a cross-section taken on the line 3-3 are being used, each strip bears an identifying 

of Fig. 2; l!O mark such as a number 14, so that the aiphabet 

Fig. 3a is a fragment of the same section on an· strips may be inserted into the channel ways 3 

enlarged scale showing the T-grip for the guide according to some preagreed key. Fo'r example, 

ruje in operative position; in Fig. 1 is shown a set of twenty-five channel 

_. Fig. 4 is a top view of the form of invention of ways into which twenty-five different alphabet 

Fig, 1 showing the guide rule in shifted position; . 25 strips 4 have been inserted according tO the. fol- , Fig. 5 is a top plan view showing another em- lowing key, reading from the top downward: 

bodiment of the invention in which the base is 14_ 16_ 9_6_22_25-23-5-12-24.:......:13-21-=.. 

c?mposed of separate detachable grooved sec- IS..:..:...i-.:...7_;17....:.._20::....:19-15-8..:.....1 j.:..._2-3-10-4 tions; 

Fig. 6. is a perspective showing one of the 

grooved sections; and 

Fig. 'i is a perspective showing a frame structure 

and ·sub-base on which said grooved sections may 

be assembled. 

30 if another embodiment of the device should include more than twenty-five channel ways, additional alphabet strips may be inserted; according 

to a longer key. 

Referring to Flg. 1, in this embodiment the de- 35 

vice comprises a base I, on which are horizontally 

fastened a series of cylindrical rods 2, forming a 

Having inserted the alphabet strips into the 

channel ways in key order, the device is now ready 

for use either to encipher a plain language mes-

. sage or to decipher a cryptogram which has been 

set of channel ways 3, into which character bear- enciphered by means of the device, alphab'ets, and 

ing strips 4, may be inserted and slid from left 

to right or vice versa. In the specific embodiment 40 

key shown in Fig. l. Suppose this plain-text mes- sage is to be enciphered : 

disclosed herein the device comprises twenty-five ACCORDING TO AN o:FriciAL RtPORT 

such channel ways, but the device is by no means FROM· l\fiLI'I:ARY AUTHo:Rr:tiEis· 

limited to this number. 'The number chosen in 

this embodiment is merely a. convenient number, Moving the reading guide 5 to the left, and 

and it may be increased or decreased within cer- 45 bnnging it against the left end bar 8, the operator 

tain limits in other einbodime:J.ts without ma- proceeds to align; in a column immediately to 

terially departing from the spirit of the invention. ~he right of the reading guide, the first twentyA rule, or reading guide 5, attached to a reading five letters of the message. This is most conven- guide slide 6, can be slid to the left or right on a iently done by placing the eraser end of a pencil 

reading guide slide rail l.' End bars 8 and 9, 50 upon the successive desired letters as found oh 

serve as stops against which the reading guide the successive alphabet strips 4 from the top 

5 may be brought at the end of its travel to the downwards, and pulling or pushing the alphabet 

left or fight. To tlie back Of the base I is fas- strips in their channel wayr,; toward the reading 

tened a hinged support 10, which can be, pulled guide so that each strip stops with the proper out to support the' device iri a· slantfng position as 55 letter just to the right of tl:le right-hand edge of 
REF ID:A4161579 

2,395,863 

the reading guide 5. When the alphabet strips are being aligned on the left-hand side of the 

device as in the above procedure, the operator confin~s his search' for letters to the left-hand 

half of the duplicated sequence on each alphabet 

strip. . . When all twenty~five alphabet strips have been 

aligned as indicated, there is disclosed a multiplii:ity of columns of letters to the right of the 

plain-text column of letters thus aligned. All 

these columns of letters, except one, are col- umns of cipher letters, each column representing a cipher equivalent of the plain-text column. 

The single exception is the colwnn which is the 

twenty-fifth removed from the plain-text column 

set up by the operator, and is merely a repetition of that plain-text column. One of these 

cipher columns is selected at random and is 

recorded in five-letter groups. The reading guide 

5 is useful in this operation, since by placing it 

alongside the column selected, reading of the 

cipher column is facilitated. Suppose that the 

reading guide 5 be moved so that its left-hand 

edge aligns a column of cipher text. As shown 

in Fig. 4, such a column would read as follows: 

SNAFJ ~ LXRJG GVWVA ATVWW PVNUT 

These letters are recorded and constitute the 

cipher letters for the twenty-five plain-text letters. 

The reading guide 5 is now moved to the ex- treme right of the device, up against the right 

end bar ·g; the next twenty-five letters of the 

plain text are aligned against the left edge of the 

reading guide 5. Again a set of ·columns of 

cipher letters are disclosed to the left of the 

reading guide. one of these columns is selected 

at random and again a set of twenty-five cipher 

letters representing the second set of twentyfive plain-text letters is recorded. If the mes- sage contains more than fifty letters, the foregoing procedure is repeated until the entire message has been enciphered. There is no need to 

indicate to the recipient of the message which 

col•umn is selected for the cipher equivalent of 

each set of twenty-five plain-text letters, as will 

be noted presently. 

To decipher the message, having the alphabets 

and the key according to which they have been 

arranged, the operator merely proceeds as in 

encipherment, aligning the alphabet strips in 

their channel ways so that the first twenty-five 

cipher letters of the cryptogram are in one col- umn. He then examines all the other twentyfive columns of letters, looking for one which 

contains intelligible text throughout its extent 

from top to bottom. There will be one and only one such column, and this will be the plaintext equivalent of the column of cipher text 

set up on the device. The reading guide 5 is 

useful in this search for the plain-text column, ns 

it can readly be moved to scan the successive col- . mnns from left to right; or from right to left. 

The plain-text column thus found' is record9d 

in word lengths and the operator proceeds to ,c;et 

up the next twenty-five cipher letters on the 

right-hand side of the device. Again he looks 

for a plain-text column and records it when . found. He continues this process until the mes- sage has been completely deciphered. 

In the form of invention shown in Fig. 2, the 

device comprises a pair of hinged components 

F-F' of metal, Bakelite or other suitable material and foldable on one another in the manner 

of a book. As here shown, the grooved slideways 3 are formed on the inner faces of the said 

components by milling, or in the case where a 

condensation product such as Bakelite is used, 

may 'be molded in the material. In the embodi-

.S ment disclosed, there are a total of thirty such 

slideways, fifteen in each component, though it 

will be understood that the invention is not limited to any particular number. It will be noted 

that the slideways are open at their opposite ends 

10 so that the alphabet strips may be readily inserted and freely extended outwardly therefrom as they are slid into different positions in the 

operations of enciphering and deciphering. As 

in other forms of the invention, a T-grip 6 is at15 tached to the guide rule 5 at its end for the purpose of manipulating the rule, and is slidable in 

a channel 20 having therein undercut grooves 21 

and 22 formed laterally along its inside edges. 

The grip 6 is provided with a spring-pressed ele20 ment 23 engaging in bottom groove 21, and having an oppositely disposed bead 24 engaging in 

the opposite groove 22 whereby the grip Ii is 

maintained under suitable sliding tension in the 

channel 20, and whereby the · guide rule 5 is 

26 manipulated transversely in relation to the alphabet strips 4; and the opposite end Of the rule 

is adapted to slide freely in a lateral undercut 

groove 25 formed in component F'. The grip 6 

is rigidly secured to the guide rule 5 in the man30 ner of a T-square and may be so manipulated 

that the rule affords a positive means of obtaining an accurate alignment in column formation 

of the characters on said alphabet strips and in 

varying relations for cryptographic purposes. 

35 This foldable form of device presents a number of 

practical advantages, among which may be men- tioned its compactness and portability; also the 

foldable feature permits exclusion of dust and 

dirt. 

40 While in one form of device here disclosed, cylindrical rods are secured to a base at regular 

intervals from one another to form the channel 

ways into which the alphabet strips are inserted, 

it should be understood that any other means 4~ may be employed to form the channel ways. 

For example, a series of elongated metal strips 

known in the trade as "card holders," used 

ordinarily to hold narrow strips of paper bearing names of mail-box owners in apartment houses, 

;)0 etc., may be used to form the channel ways; 

these card holders may be riveted to the base, or spot welded to it, or attached in any other 

suitable manner. Or as disclosed in connection 

with Fig. 2, the channel ways may be formed 

55 by milling grooves in the base I itself, which 

may be made of molded Bakelite, for example. 

In such case the grooves are made by a rotating cutter which undercuts at the two edges, 

forming a channel way such as is commonly 

60 found in slide-rules. Figure 6 shows such a section in the form of a piece of Bakelite or similar 

material 13, in which Jive such channel ways 3 

have been cut. Sections with equal or unequal 

riumbers of channel ways may be easily provided 

115 and given identifying symbols such as letters, 

A, B, C, •.. 

In Fig. 7 there is shown a sub-base suitable for use with such sections of channel ways. Thus, 

instead of having all the channel ways on a single 

70 base, as is the case in Fig. 1, the sub-base is 

merely made in the form of a flat surface onto 

which sections of channel ways may be positioned 

and temporarily fixed, so that rearrangements of 

sections ca.n be made according to subsidiary keys. 

75 Referring to Fig. 7, the sub-base la is a plane 
\ 

) 

REF ID:A4161579 

:surfa;ce :wJJ..lch .is ·provided :wi.th an :undercut slot 

14, for carrying a sliding clamp :1:5, provided with 

.a knurled.thumb.screw J&, for fastening the clamp 

'into .position. End bars 8 and 9 elevated above 

the base :by :supports I l and back stop 18, serve 5 

.the same purpose as similarly designated end bars 

-of Fig. 1. 

:Using a·sub~base such as that shown in Fig. 7, 

with ·several sections such as that shown in Fig, 6, 

.one method of -operation of this embodiment of l\l 

the invention is shown in Fig. 5. In that figure 

there are five sections .of 3, 4, 5, 7 and 8 .channel 

ways, giving a total of twenty-seven channel ways. 

Fil1st, the sections are temporarily fastened to the 

ibase in .the alphabetical order of their identifying 15 

symbols. Then the twenty-seven alphabet strips 

·would ·be inserted in the twenty-seven consecutive 

channel ways according to the predetermined 

numerical key already referred to above in .connection with Fig. 1. To encipher a -given mes- 20 

·sage, there would then be a subsidiary or specific 

key, also arranged for in advance by means ·of an 

incllcator in the message, which would direct that 

the sections be now placed onto the base in a 

mixed order, say E-D-A-B-C, as shown in ~5 

Fig. 5. The encipherment of a message would 

then proceed exactly as before. In another message, the indicator for the sectional arrangement 

might be different, say one calling for the ·sequence of sections D-A~C-E-B. Thus, with ,l\O 

five sections there could be 120 different arrange-

-ments of .sections on the base, even though only 

one set of alphabet strips is employed. The purpose of this is, of course, to increase the keying 

possibilities of the device, and to impart unique- 35 

ness to successive messages, without going ~o the 

trouble of making a complete rearrangement of 

all alphabet strips in the set of twenty-five 'channel ways. 

The many uses of this device, with variable 40 

alphabets, in crytographic or cryptanalytic studies 

will be apparent to all skilled in the art and 

nothing further need be said on this score except 

that there has existed for many years a hitherto 

unfulfilled need for a si~ple device of ·this type, 45 

suitable for the insertion of sliding alphabets. 

Changes, modifications and equivalent arrangements are contemplated within the scope of the 

invention as defined by the appended claims. 

I claim: · 60 

1. A cryptographic device comprising a base 

provided with a plurality of horizontal channel 

ways; strips provided with discrete sequences of 

equally spaced alphabetic characters adapted for 65 insertion therein and adjustable independently of 

one another and means for facilitating the reading of said characters in selected columns. 

Z. A cryptographic device comprising a base, 

said base being provided with a plurality of verti- 60 cal channel ways, and individually adjustable 

strips bearing discrete sequences of equally spaced 

alphabetic characters adapted to be slidably inserted therein; and means for facilitating the 

reading of said characters in selected columns 65 and in different relations for cryptographic purposes. 

3. A cryptographic device comprising a base 

formed with horizontally gro-oved slide-ways 

therein; individually adjustable alphabetic strips 70 

slidable in said ways; and means to facilitate the 

reading of selected alphabetic columns in varying 

relations for cryptographic purposes. 

4. A cryptographic device comprising a base 

formed with grooved slide-ways therein; strips '16 

.~. 

'.bearing tl;:u~r.eon _a;lphabetic chal'acter ~sequences 

-and individually-movable in.said ways; .and.means 

,adlustabl~ ·fransversely of said stri:Rs to :facilitate 

·the ~eadif!g of said characters in varying relations 

for .enciphering and. dec~phering messages. 

•5. A cryptographic device comprising :a .base 

having vertically grooved slide-ways formed 

therein; strips bearing thereon alphabetic character sequences and individually slidable in .said 

ways; and means adjustable transversely .of said 

strips for facilitating the reading of .said char-

-acters in varying relations for enciphering and 

deciphering .messages. 

6. A cryptographic .device comprising :a bas.e 

provided with a plurality of channel·ways; alphabet bearing strips adapted to be individually .in-

.serted and :aligned ·in varying relations in said 

ways for cryptographic purposes; and :a slidable 

guide rule for making excursions transversely 

along the channel w:ays and in relation to said 

strips for enciphering and deciphering messages. 

·7, A cryptographic device comprising _a .base 

having a supporting foot hingedly attached to 

the under surface of said base; a plurality of 

members fixed to the obverse surface cf the base 

at equidistant intervals to form a plurality of 

channel ways; strips bearing alphabetic st)-

quences of characters individually s~idable in said 

ways; a guide. rule ·adapted to be moved transversely .of said strips to facilitate the reacllng .of 

selected sequences of characters in varying relations .for cryptographic purposes; and stop.members for the .gμide rule disposed at ()pposite-ends 

of said channel ways. 

·a. A Cl'Yptographic device comprising a sub-

·base; interchangeable base-sections having 

:grooves formed therein to provide a plurality of 

channel ways; means for removably attaching 

said sections in position on said sub-base .to permit different arrangements of said sections in 

juxtaposed relationship for cryptographic purposes; character bearing strips adapted for slidable insertion in said channel ways; and a slidable guide rule movable transversely across said 

channel ways and in varying relations to said 

strips for enciphering and deciphering messages. 

9. A combination according to claim 8 in which 

said grooved sections are of the same size and 

contain equal numbers· of channel ways. 

10. A combination according to claim 8, in 

which said grooved sections are of different sizes 

and contain unequal numbers of channel ways. 

11. A combination accord~J to claim 8 in 

which stops are provided at the opposite ends of 

the channel ways to limit the movement of the 

slide rule at the end of its travel. 

12. A cryptographic device comprising a frame 

structure and including a sub-base formed therein; a series of base-sections having grooves 

therein to provide a plurality of channel ways; 

means for removably attaching said sections on 

said sub-base to permit different Juxtaposed arrangements thereof for cryptographic purposes; 

strips bearing alphabetic sequences of characters 

slidable in said ways; and a slidable gllide rule 

movable transversely of said strips and alignable 

in varying relations with respect to said c}J.aracters for enciphering and deciphering messages. 

13. A cryptographic device comprising a frame 

structure and including a sub-base therein; 

base-sections grooved to provide a plurality of 

channel ways, said sections having different numbers of said channel ways and being differentiated from one another by distinguishing symbols; means for detachably securing said sections 
REF ID:A4161579 

'2,395,863 

on the sub-base to permit different juxtaposed 

arrangements thereof for cryptographic purposes; strips bearing alphabetic sequences of 

characters movable in said channel ways; a guide 

rule slidable transversely of said strips and align- 5 

able in varying relations with said characters for 

enciphering and deciphering messages; and stop 

members at opposite ends of the channel ways to 

limit the movement of the slide rule at the end 

acters in varying relations for enciphering and 

deciphering messages. 

17. A cryptographic device composed of hinged 

sections foldable upon one another, said sections 

being provided on their inner faces with openended slide ways; strips slidable in said ways and 

bearing thereon sequences of alphabetic characters; and a guide rule hinged to fold with said 

sections, said rule ·being disposed transversely of 

of its travel. 10 said strips and movable to facilitate reading of 

the characters in varying relations for enciphering and deciphering messages. 14. A cryptographic device comprising a multiple base formed of separate sections, said sec- . tions being interchangeable with one another to 

permit different juxtaposed arrangements for 

cryptographic ·purposes; a plurality of channel 15 

ways in said sections; strips bearing sequences of 

characters and individually·slidable in said ways; 

and a guide iule movable transversely of said 

strips and alignable with said characters in varying relations for enciphering and deciphering 

18. A cryptographic device comprising a pair 

of hinged components foldable up.on one another, 

said components being provided on their inner 

faces with open-ended slide ways; a guide rule 

hinged to fold with said components; means operative with one of said components to maintain 

said rule in a position transversely of said strips 

.messages. 

20 and movable to facilitate reading of the characters in column formation and in varying relations for enciphering and deciphering messages; 

and terminal stops to limit 'the movements of 

15. A cryptographic device including a multiform base composed of separate sections, said sec- tions having grooved slide-wa.ys therein and being interchangeable with one another to permit 25 different juxtaposed arrangements for cryptographic purposes; strips· slidable in said ways 

and bearing thereon sequences of alphabetic 

characters; and guide means disposed transversely of said strips and movable to facilitate 30 alignment of the characters in varying relations 

for enciphering and deciphering messages. 

16. A cryptographic device composed of hinged 

sections foldable upon one another, said sections 

having_grooved slide-ways formed on their inner 35 faces; strips slidable in said ways and bearing 

thereon sequences of alphabetic characters; and 

guide .means disposed transversely of said strips 

and movable to facilitate alignment of the charsaid rule at either end of its travel. 

19. A cryptographic device comprising hinged 

components foldable upon one another, said com- ponents being provided on their inner faces with a plurality of slide ways; a guide rule hinged to 

fold with said components; a grooved channel 

formed along the edge of one of said components 

in parall21ism with the slide ways; means including a spring-tensioned element slidable in said 

channel for operating the said rule while maintaining the same in a position transversely of 

said strips, said rule being movable to facilitate 

reading of the characters in varying relations and 

in column· formation for enciphering and deciphering messages. 

WILLIAM F. FRIEDMAN. 

' I. 

/ 

·' 
REF ID:A41615. 

-

. March 5, 1946. W. F. FRIEDMAN 2,395,8~3 

CRYPTOGRAPHIC DEVICE 

Filed Oct. 19, 1939 3 Sheets-Sheet 1 

r-/ e. /. -".· 

, 

' 

· I - I - · I - I ·I - I - I. -I• I · 1-

I 

... 

'. -.3 

1111111 11 urn111,, · · · ~ • · ·-~·:f · · · · · · / '° ----- ----- ----------- ------ -- --- ----- -----

2o' 6 ' 

t 2/ 
.~., 

j~ 

" ·- - I 

I J. ,_.' ''/' . I 

'·· I' 

.1 

. ' 

' ,, 

I 

: 1; 

~ 

' ' 

i· 

I 

• 

. ·t_, 

I\ /• 

I . , . . . ·~ 

111 

. I 

., 

j, I . 

REF ID:A416.79 , 

J,lj-?~ 

,;-ar.fl(p~ 

, . (J!"-:P) 
REF ID:A41615-

March 5~ 1946. W. F. FRIEDMAN 2,395,863 

CRYPTOGRAPHIC DEVICE 

Filed Oct. 19, 1939 3 Sheets-Sheet 2 

•J UYG T Stt II Y~ a.•O "l 1.A.•QJ P 11,.1U1 CT. a='=';::••;:::•::::"::.::':::•='•:::•=;:•:::'°:::'::::'::::'::::~========;;;:::/=~ 

·~~~~~~· ~'='·=·====~=============:r==========1 --~~~.==.~:.·~t========:::;==';I: ~:~J'==:;:::===~==============~:;:::========1 

~========9~=.=:======~· ~-~~~~~~~~~~~1 f:=~======~· i='========~=========;.::;::::==========! ~-4~/~~~~~~3~=========3' ~·=======:'c========;;;::::=:===========1 

~~~ rr:: . p >-- ~·===;:::===~============:::::;;;===::====1 

8'. / 

// /.· 

~ / 

..3 2 g s 7 

& /8 .9 (/) ID 

' 

' 

" E 

•' A 

ll==============~==~··~.'.==================~1c , .. , 

I 

J 11 II 

~LIWlllWI-~ll11i 1l _11 ---- 17 / / 

' : 

' ' 

: ; 

' 

/4 
\. 

REF ID: A4161fl 9· 

. . 

March 5, 1946. 

W. F. FRIEDMAN 

2,395,863 

CRYPTOGRAPHIC DEVICE 

Filed Oct. 19. 1939 

3 Sheets-Sheet 3 . 
REF ID:A4161579 

Nov. 10, 1953 J. D. DURKEE 

PRINTING TELEGRAPH SYSTEM 

Original Filed Jan. 23, 1950 

2,658,941 

3 Sheets-Sheet l 

~~~~~~~ ("f 

":} 7 ~ J..lo......+-+-::ll-IP----:::-----. ~ ~ .... ~ .......,...,..____. 

~~-------

---1•1•1• 1111

11 ~ + t1') r--........_-1-1.._!J:> 

t\) C\] 
REF ID:A4161579 

Nov. 10, 1953 J. D. DURKEE 

PRINTING TELEGRAPH SYSTEM 

Original Filed Jan. 23, 1950 

::l'.I ~- 3 

/a ,...r,n,,m-..i a--....------1 

?a:. --f;f-----<;;~~ 

2,658,941 

3 Sheets-Sheet 2 
Nov. 10, 1953 

REF ID:A4161579 

J. D. DURKEE 

PRINTING TELEGRAPH SYSTEM 

2,658,941 

Original Filed Jan. 23, 1950 3 Sheets-Sheet 3 

~ ~ ... .., .. ~ 

~ 

~..., 

~ 

-- --
REF ID:A4161579 

Patented Nov. 10, 1953 

UNITED STATES PAT·ENT 

2,658,941 

OFFICE 

2,658,941 

PRINTING TELEGRAPH SYSTEM 

James D. Durkee, Fairlington, Va., assignor, by 

direct and mesne assignments, to Dualex Corporation, a corporation of Delaware 

Original application January 23, l950, Serial No. 

139,977, now Patent No. 2,613,267, dated October 

7, 1952. Divided and this application May 28, 

1951, Serial No. 228,658 

9 Claims. (Cl. 178-17) 

1 

My invention relates broadly to printing telegraph systems and more particularly to a high 

speed polarized system of printing telegraphy 

utilizing printing telegraph apparatus of compact 

size and light weight. 

This application is a division of my application 

Serial Number 139,977, filed January 23, 1950, 

now U. S. Patent No. 2,613,267, dated October 7, 

1952, for Printing Telegraph System. 

5 

One of the objects of my invention is to pro- 10 

vide a printing telegraph system constituting an improvement upon conventional sequentially operated systems, overcoming inherent difficulties in 

these systems and to supplement the purpose for 

which the system described in my co-pending ap- 15 

plication Ser. No. 109,648, filed August 11, 1949, 

for Printing Telegraph System was developed. 

My co-pending application is directed to a printing telegraph system, which when applied 

to space radio systems, overcomes conditions of 20 

fading, interference, and static, and is particular2 

but may be used with an electric typewriter or· 

with slight modification of the present printing· 

telegraph systems may be used interchangeably 

with conventional equipment. 

My invention will be more fully understood 

from the specifications hereinafter following by 

reference to the accompanying drawings in which · 

Figure 1 diagrammatically shows the transmission system of my invention; Fig. 2 is a schematic 

plan view of a fragmentary portion of the transmission keyboard; Fig, 3 is a schematic end elevational view of the transmission keyboard, the 

view being taken on sectional line 3-3 of Fig. 2 

and showing the frame structure in vertical sec- tion; Fig. 4 shows the receiving circuit of the 

printing telegraph system of my· invention; Figs. 

5 and 6 are detail views illustrating the operation 

of the control mechanism in the receiving apparatus; Figs. 7 and 8 are detailed views of the 

operating solenoids controlled by the printing 

telegraph receiving system; Figs. 9 and 10 are 

enlarged schematic views showing the operation 

of the error indicating means employed in the re- ceiving system of my invention, the views being 

ly adaptable to mobile radio printer operations 

where compactness and portability and a minimum of mechanical equipment with incidental 

maintenance are major requirements. 

The system of my invention employs a polarized 

electrical matrix which requires the transmission 

of only five polarized pulses, without the necessity 

25 shown in front elevation and wherein Fig. 9 shows 

the error indicating means in printing position 

whereas Fig. 10 shows the error indicating means 

released and free of printing position; and Fig. 11 

of transmitting start-stop or synchronizing 

pulses, to accomplish the thirty-two different ;io 

permutations and combinations of signal impulses presently used in printing telegraph sys·-

tems. 

Since in my application a smaller number of 

permutations and combinations of signal pulses 35 

are required to produce the same number of per~ 

mutations and combinations as used in currently 

existing systems, a greater number of permutations and combinations can be sent in less time 

with fewer impulses thereby requiring a smaller 40 

number of transmission bands and less frequency 

band-width. 

In addition, since the system of my invention 

requires only a reversal of current direction or 

polarity, the transition from one polarity or pha.se 45 

to the opposite polarity or phase may be accomplished by sinusoidal wave form; thus, the impact exCitation resulting from. a rapid make or 

break keying operation or from a rapid frequency shift is eliminated, thereby further de- 50 

creasing the keying band-width required at any 

speed of transmission. 

A further object of my invention is to provide 

a self-synchronizing receiving system which may 

be made operable over a fairly wide range of 55 

transmission speeds and which requires a minimum of equipment or adjustment. 

The apparatus described in this application is 

intended for use with the printing mechanism of 

my co-pending application Ser. No. 109,648 supra' G() 

is an end view of the error indicating means shown in Fig. 9. 

Almost from the beginning of the art of printing telegraph systems efforts have been made to 

accomplish the selection of characters by electrical resolution of the units of the Baudot code. 

Each solution required the use of a large number 

of electrical contacts and electro-magnetic relays 

in simultaneous operation with the resulting 

presence of a multiplicity of potential error producing elements. Practical experience indicated 

that greater reliability could be placed on me- chanical resolution and the present state of the· 

art reflects this experience. Mechanical operations, however, have the inherent· characteristic 

of requiring a longer time to perform the same 

functions than does electrical energy. 

However, operational communication requirements for increased speeds of operation have now 

exceeded the capabilities of the mechanical equipment except under strained and abnormal conditions which require excessive maintenance and· 

mechanical tolerances and precision of apparatus 

which are difficult to achieve. 

The application of printing telegraph systems 

to rndio communication also introduced additional difficulties which do not readily lend themselves to solution by mechanical methods due to 

the speed limitations of mechanical operations. 

Two of the major difficulties introduced by 

radio communication are various forms of fad-

~ng and interference in addition to the basic llin-
REF ID:A4161579 

2,658,941 

3 4 

itation Ur. thre number of( cycles. available: in~ the~ wise·- or·· a counter•clockwiSe> directiom depending 

total radio fi'equency spectrum. on the relative positions of· the bars 2:.._5 with 

Heretofore, various approaches to the radio.. respect to the centers of levers l-11, for effectapplications of printer systems have been by in- ihg momentary contact at 12-21. When prescreasing power of transmission and·' impro:v:ihg: ill sure· of: oars; Z-6 on the levers l-11 is removed 

receiving conditions in an effort to duplicate the. the_levers l-1.1 are restored to horizontal posioperating reliability of a land'. li.he to~ overcome· tion creaking the contacts 12-21 by the self 

fading and increasing the dot cycles of: opera .. - restoring_. actia.n. of: the flexing supports at each 

tion by additional fail safe impulses or increas- end· of the levers l-11. The contacts which are ing the units of the basic five' unit: code" tb. pro;,- 10; formedrdependl upom which side of the center of 

vide error detection resulting~ from- interference' levers:l~to• n, the' bars 2 to 6 are positioned. In 

and certain forms of fading; the. position illustrated in Fig. 1 lever l will con- The approach of my invention to the solution of tact· 12~ lever·B'wiU contact 15, lever 9 will contact 

the requirement for increased speeds has• been 16;. le:IOer: 1:0 will contact 19, and lever 11 will can- to eliminate the basic mechanical limitation of 15 tact 20, placing alternatively positive and negathe mechanism .. used. to_ resolve the. units_ of the. tive. currents. from. source. of. battery. 29 .. on tr:v.e, unifcode.intb cliaracters.bY. use.of. a pofarized: stepping rel'ay_ contacts 22,_ 23;, 24, 25. and. 26~ ar.,. 

electrfoal. matrix; to .. decrease. the. electrical: con,.. ranged"in;the path of'switch arm 21.of"continuo.us,. 

tacts required fo a mihihmmJ)y use. of:rectifyihg. ly cycling driven stepping refa:v.·2a: 

apparatus. and, the applicatfon, of new. and: nover 20. When tliis contact-was made a positive· current. 

eiectrica[cfrcuits-and:fo decrease. the operational- flow took. place from battery 29· (Fig. n contact 

fUI1ctibns to. a. miniinum_ by simplification. of: through. 12:. and· the. contact'. carrfed; by· lever. l. 

eqμipment and· electrfoal~circuits.. to_ stepping- relay contact. 22: througli arm 2.l: 

The. fit.ding. and·: ihterference problems ihtro- through relay: coiL n· to the. center. tap 29a, ofdilced:J:JY. radfo.communiCatfon.have oeen.accept,. 25 battery 29. The current in coil~30 caused.arma- ecr as, naturaL cliaracter-istics or: the. medium.. ture 3J to, move. down,_making contact. with con.,. 

CfrcuitS. and: ope.ratibns are prmrided. by my in,. tact 31·. whiCh.in. turn caused· the. armature. 33:of. 

vention. whicli. fake these, natilr.al: characterlstfos. stepping_ relay. 2s.· to oe_ moved: down. because. or: into. account. and: provida substitute. characteris:- the. current. ih_ relay coil: 34: pr.oduced~ by clbsing. 

tics, in_ the. form.ot:lOcallY:. produced impulses. fo 30 of" contact 32. Tlie movement of: armature. 33_ 

replace tliose.. losLin transmission. due, to fading. caused· ratchet. arm 35. to .pull. arm. 21_ away, from. or. to. counter bafance. impulSes; ihtroduced· in- contact 22 counterclockwise towar-ds steppihg. 

transmission. as. a, result. of: ihterference. and-_ to relay. contact, 23·, During. tlie time the arm- 21 

indfoate_on the. receiving, equipment-. when. these. was in. contact with contact: 22, a positive. voltfilnctions have. been. requited· to. complete the. 35 age was applied.to line 36-with.respect to ground 

fOrmation.of a chatacter.._ or center tap 29a of: battery 29,. or. was. caused. 

In. endeavor.ing. to.achieve greater. economy of. to flow through rectifier 38 through relay, coil, 38a. 

bandwidth,. the· start,,stop. or. synchronizing_ im,.. in·. a. positive dir.ection resultihg_ in. movement. of: 

pulses, heretofm:e used. in. botli radio, and. wire_ arm 39 of refay·4o·ta.make contact.at-.43. which.in. 

methods have. been. elimihated. ih my. invention 40 turn keyed the. mar.lfihg:fi:equency. of"a.frequency .. by self.-synchi:onfaihg apparatus. resulting. in an. shift radio printer. keying circuit.. · 

approximate.saving, of.twenty, per cent of: band:.. As soon as. arm 2T left. contact-. 22. the current. 

width •. required_ to: perform the functions neces,.. in relay coil 30:was.released.and contacts,3J.and. 

sacy. to. the.foi:mation_of:a character. as compared 32· were opened· de-energizihg. coff 3·4; of: the can- to systems whfoli ti'ansmit start-stop. impulses 45 tinuouslY. cyclihg,sprihg.driV.en stepping,refay 28. 

or. synchronizing; impulses.. whiCh. in turn repositioned. ratchet arm. 35". pre,.. 

MY. inventfon_ empl.Oys apparatus. and: metliods. paratory for another. ratehetihg_operatfon .. which. are compatffile_ with. exi.Stihg, methodS and' The capacit"y 4"1" and adjustable resistor 42· 

a1waratus,. allowing in alinost every instance .. the across coil 34. acts to retard, the. arm 2],. sum- use.,; with. slight". modification,. or. exi.Sting, equip- 50 cientlY. long_ at; each. contact- 22, t"o. 26 to. permit 

ment.and,methods. to.accompli.Sli.its purpose.. the full cycle of operation. previously described. 

to be completed:. 

When arm 2.l" arrived: at·_ contact. 23: the same. Transmitti.ng• apparatils 

Figs?, 1-,, 2, and· 3 .• show. the, transmission. system, cycle· of: operatfon was_ set fu motfon. as. when the, 

of;my invention; the transmitting;keyboard,being. 55 arm. 2.l'was.at:contact-.n .. except.that the charge. 

shown: in: I;!lan1 vie.w1 in•. Fig~. 2. and; ill' end view, in. of" voltage. on contact, 23: is.now derived from. the. Fig~.3,. negative source of" oattery 29, thru the. contact. 

When, the, key, 1-,. pivotally mounted. at, la,, is. on lever 8. and contact. 15 and_ a_ negative charge 

depr.essed: bar& 2., 3;. 4;, 5. and. 6. whfoh. extend, was placed,. thru rectifier. 3.l and relay coil. 3.7a. 

therefrom depress-, levers-. l.,. 8,. 9,. 10, and, 1,1. in, a 60- to ground" or center tap 29a of. battery 29; caus:-

da.wnward.direction.to.form.contact.with.the.con- ing_ armature 3"9 to close contacts. 4'4, keying tlie 

tact&.1.1 to 2.1-.. The-lever:s~l-l;I. are.suppor,ted- at, spacing. frequenc:v. of~ the. freqμency shift. keying. 

opposite: ends in, frame! 146, of; the. tr-ansmitting.. system or. causing_ a. negative.cliarg~ to be.plitced 

ke;riboa1:cl.as. shown, at .. la: and. lb.;, Ba and Sb; 9a. on lihe.36". 

and, 9b~, l:IJa, and, I Ob.;. and, I I.a: and Hb.- through: 65. The same. cY,cle. of operation fa. repeated~ at 

resilient. self.-restoring- :fiexing, strip members, stepping relay- contacts n:. 25' and: 25· resulting_ 

la'-lb'; Ba'-Bb'; 9a:-9b'.;: H.a:'-IOb!; and. in· moving arm 2l back to the original position. 

I IU.:-Ub',,. Contacts, 1-2.~2 I. are· insulatingly in contact with contact 22 having thus completed' 

supported .. in, relation ta.·frame. 146. in. alignment. a transmission CY.Cle of four self~cy:clihg_ opera~ 

with. the. pivoted. levers. l-IJ as- shown .. 'l'he. 70 tions from contact:22·to contact 26. whicli resulted 

levers, l-li ar.e nor-mal.ly. biased by, the. resilient. in sending. four equally spaced pulses. and. one. 

self r.estor-ing, :fiexing. strip, members. la'.-lb/ ;, starting pulse of alternate positive, and negative 

aa:--Sb: ;, 9a'.-9b:; I Oat-I Ob.'·;, and. I la'.-llb.', charges to a line. or causing the two.frequencies 

to ,a,.. position.in horiza.ntal planes.·and .fl.ex_ under. of.. a.frequency. shift. keying system, to be- aiter:--

the.. g.ressure. of the... bars. 2-6, in. either. a clock..,. 7 5 natively- operated·. causing- fivei pulses, divided be ... · 
REF ID:A4161579 

D,608,941 

5 

tween two different alternating currents to be 

transmitted. 

Since the pulse caused to be transmitted when arm 2l is in contact with contact 22, is the starting pulse, it does not have to be especially spaced 

in relation to any previous pulse. The pulse cre- ated by contact arm 21 with contact 26 is the 

end of the character forming combination. j 

Figs. 2 and 3 show the arrangement of the 

transmission keyboard more clearly from which 

the coaction of the pivoted keylevers 45 with 

the contact control means will be understood. 

The key-levers are arranged above the angularly 

shiftable levers l, 8, 9, IO and 11 and through bars 

2, 3, 4, 5 and 6 selectively control the· anguiar 

movement of the levers about their pivots ':a, 

lb-I la, I lb, that in turn control the contact 12, 

13, 14, 15, 16, ll, 18, 19, 20 and 21, for controlling 

the circuits heretofore described. 

When arm 21 arrives at contact 26, current 

from negative battery 29 flows through coil 46, 

arm 2l and coil 30 to the center tap 29a of battery 29. This causes armature 47 to be attracted 

by the electro-magnetic core of coil 46 ma~~ing 

contact at 48, permitting current to flow throu1gh 

coil 49 from positive battery 29 to negative battery 29. When coil 49 shown more clearly in Fig. 

3 was energized armature 50 was drawn towards 

the electro-magnetic core of the coil 49 pushing 

oscillating bar 50' against armature 51 releasing 

pressure of point 51 a of pivoted member 51 •on roller S2 carried by the end of keylever 45 permitting spring 53 to pull keylever 45 up against 

stop 54 which action lifted key bars 2, 3, 4, 5 and 

6 from bars 7, 8, 9, 10 and 11, allowing the latter 

to resume normal position. Thus permutations 

and combinations of signal pulses can be formed 

and transmitted by contacts 43 and 44 under selective control of the keyboard as described. : Had it been desired to utilize the keying mechanism in the manner described in my co-pending 

application Ser. No. 109,648 supra for simultaneous transmission of a coded character, the oscillators 40a, 40b, 40c, 40d and 40e of the circuit of 

Fig. 1 of that application would be connected to 

contacts 13, 15, 17, 19 and 21, and levers l, 8, 9, 

I 0 and I I would be connected together and returned to contact with 40/. Contacts 13, 15, 17 i 19 

and 21 would have been disconnected and lev'ers 

1, 8, 9, IO and 11, when in normal position, would 

have been making contact with contacts 12, 14 :1 s, 

18 and 20 causing oscillators 40a, 40b, 40c, 40d 

and 40e to continuously generate alternating current tones into the line 36 or an amplifier as described in my aforesaid co-pending application. 

When key I is depressed contact is broken at contacts 7, 12, at 9, 14 and at 11, 20, causing oscillators 40a, 40c and 40e to be removed from the 

line and the character which is made up of signals from oscillators l!Ob and 40d in simultaneous 

combination would be formed. 

Receiving apparatus 

Fig. 4 shows the receiving circuit for the receiving printer of my invention. The permutation and combination incoming signal pulses, 

whether received by line or as a result of rectification of a radio or audio frequency current, 

appears on line 147 of Fig. 4 as a positive or negative voltage with respect to ground 55 in 'accordance with the manner in which it was transmitted by the apparatus described in Figs. 1-3. 

The current flows through the stepping arm 61 of 

cycling switch 62 to contact 5·6 and the winding 

of relay 63 and, if the voltage is of positive pos· 

larity with respect to 55, which is the center tap 

29a of battery 29 from which the voltage on line 

141 is derived, through rectifier 64 to line 55. 

The current also flows through coil 65 from line 

IS 147 to line 55. 

When current passed through coil 65, armature 

66 made connection with contact 61 completing 

the circuit between positive battery 29 and coil 

68 and ground 55. This moved armature 69 to 

10 the left causing ratchet arm 70 to turn ratchet 

wheel 71, which caused arm 61 to move from 

contact 56 to contact 57, and through shaft 145 

caused arm 12 to move from open contact 13 to 

contact 14. 

115 When armature G6 made connection with contact 67, extension rod 6·6a connected with operating spring 1!6b the continuity of the circuit 147 

to arm 61 was broken between spring 66b and 

contact 66c, insuring against the possibility of 

20 a prolonged pulse causi!;g a false operation prior 

to the completion of the pulse duty cycle. This 

also permits the carrier or signal current to be 

maintained in an on condition during the interim 

between the formation of signal characters. 

25 When current was passed through relay '63, 

armature 78 caused extension bar l9 to pull contacts BO to Bl into connection with contacts 89, 

90, 91, 92, 93, 94, 95 and 96. 

Upon arrival of arm 61 at contact 51 the cirso cuit from line 141 through rectifier 64 to line 

55 is completed. If the voltage on line 141 is now negative, rectifier 64 will not pass current 

through relay coil 91 to ground 55 and thus 

a1mature !l9 remains in position shown and con35 tacts to I 02 are not broken. 

The current through coil 65 again caused the 

arm 61, as a result of the action similar to that 

previously described, to move to contact 58. If 

the voltage in line 147 is now positive with re- 4D spect to ground or center tap 29a of battery 29 

and the circuit is completed from line 141 

through arm 61, contact 58, coil I 03, to rectifier 

64, and line 55, the current fiow through coil I 03, 

caused armature I 04 to move bar I 05 causing 

'1:, leaf spring contacts I 06 and I ill to connect with 

contacts I 08 and I 09. 

When arm 61 arrived at contact 58 the action 

resulting from current action in coil 65 was again repeated causing 61 to move to contact 

60, 59 and arm 32 of the stepping switch 62 to move 

to contact 76. 

The arrival of arm 61 at contact 59 completed 

the circuit from line 14 l through coil 110, arm 

61 contact 59, to rectifiers 64. If the voltage is 

/Vi; now negative, rectifier 611 will not pass current 

through coil 110 to ground 55 and armature 111 

and bar 112 remain in the position shown. 

The current in coil G5 present when contact 

62 of arm 61 is in contact with contact 59 caused 

on. arm 61 to move to contact 60 and arm 12 to move to contact 77. 

Line 14 l is now connected thru arm 61, contact 60 and contacts 113, 107, 109, IOI, 85 and 94, 

to the printer magnets N and SP, to rectifiers 

65. 114 and 115 to line 55 through lead 55a. 

If the voltage in line 147 was positive when 

contact was made by arm 6 f at contact SO, a positive current will now pass through the printer 

magnets N (Fig. 4) and rectifier 115 to and by 

70 the process described above. This will cause the 

letter N of the printer to print. 

When the letter N function was activated by 

the action of arm 61 contacting contact 60, current also passed through relay coil 116 in the 

715 lead 55a which caused armature 117 to unlatch 
REF ID:A4161579 

2;fm8JMi'I 

~ & 

aonatur.esi Tll;. 94;. 1:0.41 and: I I.I of: r.elaY..si 63,. 9J;, · circuitt armc&Ji provides!thr_ough~itsrcontac.t with! 

111.31 and) U.lt.pr.epar.ing: the1 system to:, r.eceive. a< contacts 56 to 60, thus producing thei sa;me; ac:-. new; cycle of cliaracter;forming impulses: tion. which\ would·:have:.resulted1 fr.om1 an.Jncom:-

Examination'. of. Fig,_ 4: will• show: that;. predi~ ing-signaI:on:line" 147c 

cated upon the polarity of the currents, in line: 5, When this:.current' passed: through:. coil 1321thec 

14'1• with· respect:. to_ line: 55:. as; presented to, the armature_ 133.1 was- moved· and: closed: the circuit: 

matrix! shown: in,the!lower:right~ hand-;por,tion1 Ofi through contact~ I 33a: connecting battery, 29i to, a·i 

Ffg.:. 4'. in; sequential combination and with, the, relay 13_4rassocfated with the printing:mechanism~. 

usei of:' pr.essure: roller~ springs I.I a; I 11.9.;. 1·20: and; When the r.elay: 13.4 was energized, the arma12ill to· latch·. armatm.e:. 18,. 98·; I 0.4:· and: 1:1 I. in a-, 101 ture 1 1351 was attracted: to the pole. of: coil~ 1:34·; 

fixed1 position for· a period·. covering-the cycle: of- latching itse}f·toJatching:armature; I 36mnd~bring;.. 

operation;.it:is~possible· to individually.cselect: any_· ing·the:extension wire I 3l•of: armatureJ 135! across, one of the. multiplicity• of: magnets: in: various: the· surface, of the: character,· A. for: example on1 

permutations and combinations represented' bY· the ·type~pallet.1,38 which may. strike~thet ink;rib;.. 

reference; "Let"· designating. "Letters'." to "Blk" 15~ bon. 139. of: F.ig~. lt and: be: prihted on:. the paper· 

designatihg' "Blank~" of Fig. 4·. In.Figs; 5 and: 6· web 1.40· being; advanced< on'- platen. 14:1r of: the·. 

I liave,showrnthe'. two, limiting positions of arma~ printer; astshowrn more~clearly.' in' F.igs; 9 and-10;. 

ture_ I lill on.an~ enlarged: scale: to illustrate:· the: and:.lL F.ig. 9;shows.the!condition.for:indicating 

two exfu'eme:,latched:positions1 ther.eof under·con:-· error while Fig. 10·- shows'. an· all: clear. condition_ 

troLof; pressure·roller:spring, lrl8 .. All of.-the. ar• 20l with! thei error, indicator removed. 

matures. 18;. 98;. 104> are arranged: in. a._ manner: When:relay·l:l.'lilwas:energized'contact:was;made. 

similar to: armatur.e: 11;1-, that. is the armatures'. between'. 144', and 1:11\. placing• battery; ontcoil'. "4'2. 

78; .. 99, and'. 1041 are controlled~ irr. their: limiting, which: caused armatur.e 136; to~ release~ armature, 

positions' by.· pressure~_ roller springS'. 1211, 120: and1 135~.allowing spring1 L43; to draw· armature: 1:351 tot 

I 1,9; respectively: 25; itsi normal; position1 with• the. extension. 13 lJ clear.· 

Figs .. 7i and 8' are enlarged: views·: of the, sole;,.. of- the: printinm surface. oft the: next: character.· 

noidS< im the• polarized. matrix' circuit: wherein placed:in·,a:printing:position. 

Fig. 7 represents the juxtapositions; of' the op,- When; the letter: key.• is.: operated to~ prink the; 

erating· solenoids: for letters. w andi k. and: let·- character formed,.partly·by:the!self;;.imposed~im,,.. 

ters .. Z and\. E: while·. Fig;. 8T shows the, electrical1 30: pulses: of: condenser.· 130; the. character which .. is. 

equivalent: of the same ju,.tapositionedisolenoids:. printed will: be-. marked: by· a, ver.tical· bar· stroke; 

The, capacitor-resistor combination 122: and._ by.· the extension. bar, I 3.111 of:. armature! 1·35S-plain~. 

123; are. used to. control: the dissipation. ofi cur.'- ly;· indicating to the· operator that. the! charader· 

rent>. in. condenser. 121 through coile 68! after open;. was: not. properly' received:. 

ing of the circuit to battery.• 29 c+ )' by. the. op- 35 The: rotary; selecting. printing; mechanism1 de;. 

eratibn- of· refay, 65 and· which' in. turn. controls scribed·: in·_ my, co,.pending: application Ser. No;. 

the1length1 of-'time•in·which arm. 61, moves, from. 109;648'. supra .. may• be used'. in·_ connectiom with'. one. contact• to- the• other. of the, group of con- the· apparatus described: in, this application· to. 

tacts 56• to 60: select and: print; the; characters: and perform the: 

Under 1 certain. conditions of' ope1,atiom par-. 40 other operations. r.equired or a·_ printing: mecha.-

ticufarly· in radio circuits. the possibility or.· 1oss' nism. This: may be'. accomplished. by connecting: 

of" one or. more. impulses· due·. to· fading or oblit- theJ contacts of: the; rotar.y, ·switch and the! "I!iet;.. 

eration• or signali;. by. inter.ference. is always pres~- ters;'.'· "Figures'.'• and' "Space"- relays; toi the\ con,.. 

ent: tacts; represented: by. thet solenoids' for. Letters-. K,_ 

To overcome this condition, provision has:oeen 45 Wr, etcJ.Of:Fig~ 4._ 

made in the selector system- for the supplying• It will be. fully· understood that·: these; same' 

of1 lbst• impulses and' recording this circumstance contacts ofr Fig: 4;.can1 be connected'. to• a series; of;' on• the printed COPY'· The· effect of' interference·, solenoids: or: magnets and1 be. used, to, operate: an: is made· to, appear as a lost' impul.Sec inc this: electric.typewriter:or-initiate.the•printing,mecha,.. 

system. 50: nism- of other.· types, of: presentlY. used1 printing. 

Each time that the armature 66 is in contact: telegraph equipment; · with· contact 1z4: in· addition' to: holding• arma- <i:onventional printer·mechanismds·operated.by; 

ture-1:25- in contact· with contact 126; batte:r.y. 29! the~ solenoids; Letters; through· Blank: shawm in; 

( +·) charges- the condenser resistor. delay net- the; polarized' matrix in the.• low.er~ left: corner of: 

work-> IZT- and' 12s: across. coil' 129\ Each. time· 66 Fig: 2: 

the·armat·ure 66)is opened! by removal- of. energy• Due: to the fact that~ the necessity; for.· a me:-. from coill 65, contacts 66' and' 124: are broken- chanicat selector, is eliminated· in• the, printer, sYS'-

which· opens· the circuit from. positive battery tern: of' my. invention and: yet·· vecy. accurate and: 

291t;0.negative•battery.·291through coil'- 129. When· quick· movement• of.' the· selection system of. my. 

thil> occurs the- energy. stored· in capacitor In· 60 invention ootained: by' use ·of: positive- and: nega-. 

starts discharging through resistbrs• l-28l an<f: tive electrical impulses; r: am: able· to reduce the· 

128a· ihto· coiF 12·9• holding. armature 125 that' is size and weight of. the. equipment,, as compared 

in.circuit' with condenser I 30'through contact' 126· to conventional equipment, very materially. 

to•battery 29~ While: I· have• described( my. invention' in cer.- If no voltage• appears. on- line· 141 for· a fixed 611" tain· of.:·its; preferred: embodiments: Ir realize· that'. 

period: of· timei after contact has been estab- modifications may:· be- made• and: Ii desire that it 

lished• by arm 6'f: with any. one of' the· contacts· be· understood: that no'. limitations. upon my in'-

51;.58;'.59 and 60;before the:dissipation of-energy; vention.are-.intended other·tharr.may be>imposed 

in condenser 12] is complete, armature. 125· will: by .. the•scope•ofithe·appended.claims:. 

be~ released from contact' 126: and: contact" will 70' What. I claim as. new and' desire to• secure by· 

be established with• contact: 13:1' allowing con- Letters: Patent of: the- United; States is· as• fol:... 

denser; 130 to· discharge: through. resistor 130a·, lows:· 

coil! ~·32,_arrn 12; and~ contact: l4, 75;. l.6: ore n~of. a. 1. A· printing· telegraph· system comprising w 

duphcate bank: of. contacts- on. the. same shaft as: transmission system for• selectively establishing• 

contact, arm• G"I: tm line: 1·0 through: which ever· 76 1 permutatfons. and' combinations- ofl positive' and; 
~ . 

REF ID:A4161579 

2,658,941 

9 

negative current pulses, a keyboard selectively operative to establish permutations and combinations of positive and negative current pulses 

representative of different signal characters, a stepping relay including an actuating winding, 5 

a switch arm and a multiplicity of contactors controlled by said switch arm, an armature con- trolled by said winding, said switch arm being 

angularly shiftable step-by-step under control 

of said armature over said multiplicity of con- 10 

tactors associated therewith, and_ a polarized ;relay circuit responsive to said positive and negative current pulses selectively controllable through 

the circuits established by the movement of said 

angularly shiftable arm for controlling the se- 15 

lective transmission of signal impulses. 

2. A printing telegraph system as set forth in 

claim 1 in which said keyboard for controlling 

the establishment of permutations and combinations of positive and negative pulses which I are 20 

applied to said polarized relay includes finger 

actuable levers extending over a plurality of lever 

members disposed in directions normal to the direction of said finger actuable levers said lever 

members each being centrally pivoted and biased z:; 

to open circuit position, contacts carried bY; the 

peripheries of said members and coacting with 

aligned fixed contacts and selector means carried by said finger actuable levers and movable 

into the path of said lever members for selective- 30 

ly moving said lever members either in clockwise · 

or counterclockwise directions for selectively closing predetermined combinations and permutations of said contacts. 

3. A printing telegraph system as set forth in ·'" 

claim 1 in which said keyboard includes key levers 

pivoted at one end and having a finger actuating 

means at the other end and selectively movable 

to an actuated position from an unactuated position for establishing permutations and combina- '10 

tions of positive and negative current impulses 

for application to said polarized relay, and means 

engageable with the end of the lever that carries 

said finger actuating means for selectively maintaining said key levers in actuated position. .

1:, 

4. A printing telegraph system as set forth in 

claim 1 in which said keyboard includes key levers 

pivotally mounted adjacent the rear ends thereof in a frame and selectively operative in either an actuated or unactuated position, a plurality of :.o 

lever members extending in directions normal to 

the direction of said key levers and pivoted at 

their opposite ends in said frame in a plane 

beneath said key levers, depending members car- ried by said key levers selectively engageable with :,;; 

the peripheral edges of said lever members, said 

lever members carrying 'contacts adjacent their 

peripheral edges and coacting with aligned fixed 

contacts, said lever members being biased to positions normally maintaining said contacts and (IO 

fixed contacts in open circuit position and said 

depending members operating upan actuation of 

selected key levers to move said lever members 

selectively clockwise or counterclockwise for closing said contacts for effecting the transmission fl5 

of positive and negative current pulses to said 

polarized relaY, and means located adjacent the 

front of said key levers for selectively maintaining said key levers in either actuated or unactuated positions. 70 

5. A printing telegraph system as set forth in 

claim 1 in which said actuating winding has an 

adjustable retarding circuit associated therewith 

for adjustably prolonging the cycle of operation 

of the circuits established by the movement of 75 

10 

the angularly shiftable arm step-by-step over 

said contactors. 

6. A printing telegraph system as set forth in 

claim 1 in which said actuating winding has a condenser and an adjustable resistor connected 

in shunt therewith and controllable to electrically 

retard the cycle of operation of said angularly 

shiftable arm with respect to the associated con- tactors for completing a full cycle of operation 

for each position of the angularly shiftable arm 

with respect to an associated contactor. · 7. A printing telegraph system as set forth in 

claim 1, in which said key.board includes a frame, 

depressible levers pivoted at one side of said 

frame, bars associated with each of said levers, 

horizontally extending lever members disposed 

substantially normal to the direction of said depressible levers and pivotally mounted at their 

opposite ends in said frame, contacts positioned 

on said pivotally mount.ed lever members on opposite sides of the paths of movement thereof 

whereby said lever members are selectively moved 

in either clockwise or counterclockwise directions 

for closing electrical circuits for the establishment of said positive and negative current pulses, 

by contacting abutment of said bars with t.he 

upper surfaces of said lever members. 

8. A printing telegraph transmitter comprising 

a frame, a set of fixed contacts mounted in prearranged positions adjacent the base of said 

frame, a plurality of lever members extending 

substantially the length of said frame in a plane 

above said fixed contacts, means for mounting 

said lever members in opposite ends of said frame 

in positions wherein said lever members may flex 

sideways about longitudinal centers from a horizontal position and be restored to the normally 

horizontal position thereof, contacts carried by 

the peripheral edges of said lever members in 

alignment with the aforesaid fixed contacts, key 

levers pivotally mounted at one side of said frame 

and extending in directions normal to the longitudinal centers of said lever members to a position adjacent the other side of said frame and 

selector bars depending from said key levers in 

prearranged positions for engaging the tops of 

said lever members in positions displaced from 

the longitudinal centers thereof and applying 

pressure thereto for flexing said lever members 

about said longitudinal centers through a sufficient displacement for moving the contacts 

carried thereby into contacting relation with said 

aligned fixed contacts for establishing permutations and combinations of signal pulses in a transmission circuit connected with said contacts. 

9. A printing telegraph transmitter as set forth 

in claim 8 in which the bars depending from said 

key levers are variably spaced along the length 

of said key levers in positions for striking said 

lever members on opposite sides of the longitudinal centers thereof whereby to selectively orient 

the respective lever members clockwise or counterclockwise about the longitudinal centers thereof for moving the contacts carried by said lever 

members into contacting relation with said fixed 

contacts for establishing the permutations and 

combinations of pulses comprising the telegraph 

signals. 

JAMES D. DURKEE. 

References Cited in the file of this patent 

UNITED STATES PATENTS 

Number 

2,262,321 

Name Date 

Gundlfinger ________ Nov. 11, 1941 
July 18, 1939. 

~ l ' 

REF ID:A4161579 

W. F. FRIEDMAN ET AL 

ELECTRICAL SWITCHING MECHANISM 

Filed Aug. 19, 1935 

ff:; I 

. i 

I 

2,166,137 

ATTORNEYS · 

,, 
REF ID:A4161579 

July 18, 1939. W. F. FRIEDMAN ET AL 2,166,137 

ELECTRICAL SWITCHING MECHANISM 

Filed Aug. 19, 1935 

,2. .z 2' 

ATTORIVL:YS 
REF ID:A4161579 

Patented July 18, 1939 2 166 137 

' ' 

UNITED STATES PATENT OFFICE 

I 2,166,137 

ELECTRICAL SWITCHING MECHANISM 

William F. Friedman, Washington, D. C., and 

Frank B. Rowlett, East Falls Church, Va. I 

Application Au):-ust 19, 1935, Serial No. 36,868 

10 Claims. (Cl. 200-17) I 

(Granted undei"i the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) I. 

· The invention described herein may be hianufactured and used by or for the Government for 

:governmental purposes, without the payment to 

us of any royalty thereon. I 

· IS This invention relates to a switching mechanism and proposes a mechanism of this character 

for automatically establishing and/or varyihg circUit connections in a random order. I 

As distinguished from the idea of performing 

'IO switChing operations in an orderly sequence, the 

present. invention contemplates an opposite function_ an~ provides means to vary the circuit con- ·nections in an irregular, aperiodic or fortuitous 

manner. The invention contemplates an bpera15 · tiOn which affords opportunity for the laws of 

·:Probability to function in establishing the 'varia-

"tion 'in circuit connections, rather than an bperation controlled by the usual laws of direct cause 

. and effect. An object of this invention is to 

20 provide a means of selecting from a plurality of 

available electrical circuits a single circuit at 

random, which electrical circuit will be operative 

·for a period of time, the length of which depends 

.upon one or several variable factors. ; 

· 25 Another object of this invention is to provide 

apparatus for varying the speed of rotating bodies . by means of a friction drive mechanism working 

in confonction with cam wheels of irregular outline and operatively coordinated with a differ30 _ ential gearing system for the purpose of oi>ening 

and closing electrical circuits for varying periods 

o'f time. I 

A further object of the invention is to provide a device in the nature of a fortuitously-operated 

35 · device for selecting from a large assortment of 

punched cards, a random sample. 

A further object of the invention is to provide a 

device in _the nature of a scrambling devi'ce for 

arranging in a purely random sequence, a large 

40 number of punched cards orfginally arranged according to a definite sequence, such as an alphabetical or numerical sequence. For example, in 

the well-known card-sorting machines employed 

in accounting or statistical work, the function of 

45 the machine is to arrange a large number of 

punched cards in a sequential order, such as alphabetical or numerical. In certain types of operations with punched cards it is .often necessary 

to disarrange the cards so as to destroy the origi-

. 50 nal sequential order and bring the cards into a 

purely random order. However, once a large 

number of cards has been sequentially arranged, 

any attempts to destroy the arrangement by 

shuffling the cards would be extremely tedious and 

55 many cards would be damaged. In the present 

invention, the device if operated in connection 

with an ordinary card-sorting machine, would 

permit of placing a sequentially-ordered batch of 

cards in the machine and taking out of it a purely 

fortuitously-ordered batch of cards. · 5 

In order that the invention and its mode of 

application may be readily understood, there is 

disclosed in the accompanying drawing and in 

the detailed following description thereof, one form or embodiment of the invention. 110 

In the drawing, the single figme shows in schematic form an apparatus for carrying out the 

invention. 

Referring to the drawing, I is a gear, driven 

by any prime mover such as a motor M; gear I ;15 

meshes with the two gears 2 and 2', having different numbers of teeth. Gear 2 is fixed to shaft 3 

and drives the worm gear 4, which in turn, 

through the train of gears 5, 6, l, drives shaft 8, 

on which is mounted cam 9 of irregular outline. r20 

Roller I 0 rides on the periphery of cam 9 and 

serves to move lever 11, through a succession of 

angles which are determined by the depressions 

and elevations of cam 9. The free end of lever 

11 is connected by a pin 12 to a collar 13 which '25 

is free to slide up and down on shaft 3 but is 

independent of the latter in its rotation. The 

upper end of collar 13 presses against disk I 4, 

which is also mounted on shaft 3 but, by a slot 

and bar arrangement, is driven by sha.ft 3. , 30 

Spring 15 serves to keep the assembly 12, 13, and 

14 in place on the shaft 3 and also to cause the 

roller I 0 to follow the outline of cam 9. Disk 

14, by frictional effect, drives wheel 16, keyed to 

shaft I l so that as shaft 3 turns disk 14 turns ; 35 

and slides up and down against the fa.ce of wheel 

16, causing shaft I l to rotate at continuously 

varying speeds as the roller I 0 rides on the periphery of cam 9. Inherent in the mechanism 

here disclosed and as the result of such a friction • ·.10 

drive a slipping action is produced, which action 

is aided by the sliding movement of disks 13 and 

13' on the face of wheels 16 and 16', respectively. 

The cams 9 and 9' as well as the system of gearing 

previously ·described, contribute an important. 45 

part to this slipping action and consequent lost 

motion whereby the switching operation is performed in an irregular, aperiodic or fortuitous 

manner. This constitutes an important object 

of the invention all as fully set forth .in the speci- : iJO 

fication and shown in the drawing. On the shaft 

ll is mounted the commutator generally designated as 18 and a contact wheel 19, provided 

with a plurality of contacts 20, connected in a 

random manner to the commutator rings 21, 22, 55 
REF ID:A4161579 

2 2,166,137 

23, 24, 25. Resting against the commutator rings 

are collectors 26, which are connected to conductors 27 leading to individual circuits, which 

circuits may include any conventional means or 

5 instrumentalities suggested, schematically as at 

33 for utilizing the randomizing function of the 

present invention. 

The action of the members 2 to 17 inclusive 

is the same as that of the members 2' to 17'. 

10 Shaft ll' rotates switch arm 30, carrying brush 

31 which sweeps over the contacts 20 as it rotates. 

The commutator assembly which essentially comprises commutator 18 and its associated parts, including contact wheel 19, may be regarded as 

15 one component of a switching device, while 

switch arm 30 carrying brush 31 may be regarded 

as the other component of said switching device. 

Brush 31 is connected to the common return 

conductor 32 for the circuits Ri, R2, RJ, R4, R5 to 

20 which conductors 21 lead. Since wheel 19 and 

brush arm 30 rotate in different directions and 

at constantly varying speeds, the circuits R1, R2, 

RJ, R4 and R5 are selected in the order of the 

contacts 20 on wheel 19, but each circuit is op25 erative for a different interval of time. 

In the drawing, specific mechanical principles 

are shown for effecting the movements of the 

various parts of the apparatus. However, these are shown only for the purpose of demonstration 

30 of the principles incorporated in this invention, 

and it is pointed out that any other mechanical 

means for varying the angular velocity of the 

commutator 18 rotating with contact disk 19 and 

the contact arm 30, either separately or con35 jointly, will effect the result desired. It is also 

pointed out that, while five commutator rings are depicted in the drawing, any number may be used, 

and that the number of contacts on the face of 

the disk 19 may be equal to the number of con40 tact rings or greater by any practicable number. 

It will also be noted that cams 9 and 9' are intended to be detachable and interchangeable, 

means being shown in the drawing to facilitate 

removal for that purpose, or to permit substitu45 tion of other cams of different shape. 

Changes, modifications and equivalent ar- rangements are contemplated within the scope of 

the invention as defined by the appended claims. 

We claim: 

50 1. In a mechanism of the character described, a pair of rotating bodies associated for operative 

movement relative to one another; friction drives 

having a slipping action and arranged to actuate 

said bodies in a discrete time relation; and means 

55 including a system of differential gearing and cams of irregular contours operatively coordinated with said gearing and with each of said 

·drives individually to aid the slipping action and 

to effect aperiodic movement of said bodies rela60 tive to one another. 

2. A mechanism of the character described for 

controlling the operation of an electrical system, 

comprising a rotatable commutator provided with 

contact elements and a rotatable switching device 

65 operable with said elements for establishing a 

plurality of circuit connections; and means to 

effect a random operation of said system comprising variable driving units for operating said 

commutator and said switching device asynchro70 nously, and means for differentially controlling 

the operation of the units. 

3. A combination according to claim 2, in 

which the last named means includes cams of 

irregular contours individually operable with 

said units. 

4. A combination according , to claim 2, in 

which the last named means includes cams of 

different irregular contours. 5 

5. A switching mechanism comprising in combination, a rotatable commutator provided with 

contact elements and a rotatable conductor operable with said elements for establishing a plurality of circuit connections; independently vari- 10 able friction drives for operating said commutator and said conductor respectively; and means 

including differential gearing, and cams of irregular contours operatively coordinated with 

said gearing and individually with each of said 15 drives to vary the circuit connections aperiodically. 

6. A randomizing switching mechanism of the 

character described, comprising a rotatable commutator provided with a plurality of contact ele- 20 

ments and a rotatable conductor operable with 

said elements for establishing a plurality of circuit connections; and means for continuously 

and irregularly changing the relative speed of 

said commutator and said conductor to vary 25 the circuit connections aperiodically, said means 

including a friction drive operative with the commutator and conductor individually, cams of 

irregular contours operatively coordinated with 

each drive, and gearing for actuating the cams 3_0 differentially. 

7. A mechanism for controJling the. operation 

of an electrical system, comprising relatively ro.- tatable switching devices provided with cooperating contact elements for establishing a plu- ,

35 rality of circuit connections; and means for contimwusly and aperiodically varying the relative 

speed of rotation of said switching devices, said 

means comprising change speed drives individually operative with said switching devices, fn- ,

40 terchangeable cams of different irregular con- · 

tours operative with said drives, and a differential 

gearing system for operating the cams and drives 

in opposing relation. 

8. A mechanism of the character described, Al) 

comprising switching components movable relative to each other and provided with contacts 

for establishing a plurality of circuit connections; and means including continuously slipping 

drive elements and cams Of irregular contours 50 operative with each component for continuously· 

and irregularly varying the timing of the contacts in a random manner. 

9. A switching device comprising components 

provided with electrical contacts, said. compo- _.55 nents being rotatable with respect. to each. other 

for establishing a plurality of cil;cuit connections; 

a friction drive mechanism for each of said components, and including means for separately and 

differentially operating said mechanisms to vary 60 the timing of the circuit connections in a random ' manner. 

10. A switching mechanism, comprising relatively movable components provided with contacts for establishing a plurality of different 

circuit connections; means for varying the circuit 65 

connections, comprising frictional drive mechanisms operable variably with said components; 

and means for changing the rate of movement 

of said mechanisms to assist in randomizing the 

circuit controlling operation of the contacts. · 70 

WILLIAM F. FRIEDMAN. 

FRANK B. ROWLETT. 

I 

•i 

! 

' i 
l, 

._ I 

I 

.f 

REF ID:A4161579 

Patent~d· July 18, 1939 2~166,137 

':~ : T 

·~.' .... 

~; .. UNITED STATES :- ·,.. .- .. \,\ PATENT OFFICE 

2,166,137 

ELECTRICAL SWITCHING MECHANISM 

William F. Friedman, Washington, D. C., and 

Frank B. Rowlett, East Falls Church, Va. 

Application August 19, 1935, Serial No. 36,868 

10 Claims. (Cl. 200-17) Cl' 

(Granted unde~ :the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) 

· The· invention described herein may be manufactured and used by or for the Government for : go'verriinental purposes, without the payment to 

·us of any royalty thereon. 

G This invention relates to a switching mechanism and proposes a mechanism of this character 

for automatically establishing and/or varying circuit connections in a random order. 1 

As distinguished from the idea of performing 

10 switchln'g operations in an orderly sequence, the 

present invention contemplates an opposite func-

' tioh and provides ·means to vary the circuit .connections in an irregular, aperiodic or fortuitous 

manner. The invention contemplates an opera15 tfon which affords opportunity for the laws of 

·probability to function iri establishing the variation in circuit' connections, rather than an operation controlled by the usual laws of direct cause and effect. An object of this invention is to 

20 provide a means of selecting from a plurality of 

available electrical circuits a single circui't at 

random, which electrical circuit will be operative 

for a period of time, the length of which dep~nds 

upon one or several variable factors. 

·25 Another object of this invention is to provide 

apparatus for varying the speed of rotating bodies 

by means of a friction drive mechanism working 

in conjunction with cam wheels of irregular outline and operatively coordinated with a differ-

· 30 ential gearing system for the purpose of opening 

and closing electrical circuits for varying periods 

of time. 

A further object of the invention is to provide a device in the nature of a fortuitously-operated 

35 -de.vice for selecting from a large assortment of 

.Punched c;ards, a random sample. 

A further object of the invention is to provide a 

device in the nature of a scrambling device for . 'arraqging in a purely random sequence, a large 

40 number of punched cards originally arranged according to a definite sequence, such as an alphabetical or numerical sequence. For example, in 

'the well-known card-sorting machines employed 

in accounting or statistical work, the function of 

45 the machine is to arrange a large number of 

punched cards in a sequential order, such as alphabetical or numerical. In certain types of op-

:eratiol).s with punched cards it is often necessary 

to disarrange the cards so as to destroy the origi50 nal sequential order and bring the cards into a 

purely random order. However, once .a large 

number of cards has been sequentially arranged, 

any attempts to destroy the arrangement by 

shuffling the cards would be extremely tedious and 

55 many cards would be damaged. In the present 

invention, the device if operated in connection 

with an ordinary card-sorting machine, would 

permit of placing a sequentially-ordered batch of 

cards in the machine and taking out of it a purely 

fortuitously-ordered batch of cards. · 11 

In order that the invention and its mode of 

application may be readily understood, there is 

disclosed in the accompanying drawing and in 

the detailed following description thereof, one ·form or embodiment of the invention. •10 

In the drawing, the single figure shows in schematic form an ap·paratus for carrying out the 

invention. 

Referring to the drawing, I is a gear, driven 

by any prime mover such as a motor M; gear I ;15 

meshes with the two gears 2 and 2', having different numbers of teeth. Gear 2 is fixed to shaft 3 

and drives the worm gear 4, which in turn, 

through the train of gears 5, 6, l, drives shaft 8, 

on which is mounted cam 9 of irregular outline. · 20 

Roller I 0 rides on the periphery of cam 9 and 

serves to move lever I I, through a succession of 

angles which are determined by ·the depressions 

and elevations of cam 9. The free end of lever 

11 is connected by a pin 12 to a collar 13 which ;25 

is free to slide up and down on shaft 3 but is 

independent of the latter in its rotation. The 

upper end of collar 13 presses against disk 14, 

which is also mounted on shaft 3 but, by a slot 

and bar arrangement, is driven by shaft 3. 30 

Spring 15 serves to keep the assembly 12, 13, and 

14 in place on the shaft 3 and also to cause the 

roller I 0 to follow the outline of cam 9. Disk 

14, by frictional effect, drives wheel 16, keyed to 

shaft 17 so that as shaft 3 turns disk 14 turns ;35 

and slides up and down against the face of wheel 

16, causing shaft 17 to rotate at continuously 

varying speeds as the roller 10 rides on the periphery of cam 9. Inherent in the mechanism 

here disclosed and as the result of such a friction qu 

drive a slipping action is produced, which action 

is aided by the sliding movement of disks 13 and 

13' on the face of wheels 16 and 16', respectively. 

The cams 9 and 9' as well as the system of gearing 

previously described, contribute an important, 45 

part to this slipping action and consequent lost 

motion whereby the switching operation is performed in an irregular, a.periodic or fortuitous 

manner. This constitutes an important object 

of the invention all as fully set forth in the speci- , 50 

fication and shown in the drawing. On the shaft 

11 is mounted the commutator genefally designated as 18 and a contact wheel 19, provided 

with a plurality of contacts 20, connected in a 

random manner to the commutator rings 21, 22, 55 
. ; .:~ .. 

REF ID:A4161579 //', 

23, 24, 25. Resting against the comniutator rings 

2,166,137 

irregular contours individually operable With 

~ 'i are collectors 26, which are connected to con- said units. 1 

2 

ductors 21 leading to individual circuits, which 4. A combination according ,to claim 2, i_n "" 

circuits may include any conventional means or which the last named means includes cams of 

5 instrumentalities suggested, schematically as at different irregular contours. 

33 for utilizing the randomizing function of the 5. A switching mechanism comprising in compresent invention. bination, a rotatable commutator provided with 

The action of the members 2 to IT inclusive contact elements and a rotatable conductor opis the same as that of the members 2' to I l '. erable with said elements for establishing a plu5 

lO Shaft IT' rotates switch arm 30, carrying brush rality of circuit connections; independently vari- 10 

31 which sweeps over the contacts 20 as it rotates. able friction drives for operating said commuThe commutator assembly which essentially com- tator and said conductor respectively; and means 

prises commutator I B and its associated parts, in- including differential gearing, and cams of ircluding contact wheel 19, may be regarded as regular contours operatively coordinated with 

15 one component of a switching device, while said gearing and individually with each of said 15 switch arm 30 carrying brush 31 may be regarded drives to vary the circuit connections aperiodias the other component of said switching device. cally. · 

Brush 31 is connected to the common return 6. A randomizing switching mechanism of the 

conductor 32 for the circUits R1, R2, RJ, R4, R5 to character described, comprising a rotatable com2o which conductors 21 lead. Since wheel 19 and' mutator provided with a plurality of contact ele- 20 

brush arm 30 rotate in different directions and ments and a rotatable conductor ·operable. with 

at constantly varying speeds, the circuits R1, R2, said elements for establishing a plurality of CirRJ, R1 and R5 are selected in the order of the cuit connections; and means for continuously 

contacts 20 on wheel 19, but each circuit is op- and irregularly changing the relative speed of 

25 erative for a different interval of time. said commutator and said conductor· to vary 25 

In the drawing, specific mechanical principles the circuit connections aperiodically, said means 

are shown· for effecting the movements of the including a friction drive operative with the comvarious parts of .the apparatus. However, these mutator and conductor individually, cams .. of 

are shown only for the purpose of demonstration irregular contours operatively coordinated with 

30 of the principles incorporated in this invention, each drive, and gearing for actuating .. the cams ;

30 

and it is pointed out that any other mechanical differentially. 

means for varying the angular velocity of the 7. A mechanism for controlling. the operation 

commutator 18 rotating with contact <.lisk 19 and of an electrical system, comprising relatively rothe contact arm 30, either separately or con- tatable switching devices provided with .. cooper35 jointly, will effect the result desired. It is also ating contact elements for establishing .a plu- :

35 pointed out that, while five commutator rings are rality of circuit connections; and means .for con- ' 

depicted in the drawing, any number may be used, tinuously and aperiodically varying the relative 

and that the number of contacts on the face of speed of rotation of said switching devices, said 

the disk 19 may be equal to the number of con- means comprising change speed drives. individtact rings or greater by any practicable number. ually operative with said switching devices, in- r

40 It will also be noted. that cams 9 and 9' are in- terchangeable cams of different irregular .contended to be detachable and interchangeable, tours operative with said drives, and a differential 

means being shown in the drawing to facilitate gearing system for operating .the cams and drives 

removal for that purpose, or to permit substitu- in opposing relation. 

45 tion of other cams of different shape. 8. A mechanism of the character described, .

45 Changes, modifications and equivalent ar- comprising switching components movable relarangements are contemplated within the scope of tive to each other and provided with contacts 

the invention as defined by the appended claims. for establishing a plurality .of circuit connecWe claim: tions; and means including continuously slipping 

50 1. In a mechanism of the character described, drive elements and cams of irregular contours .

50 a pair of rotating bodies associated for operative operative with each component for cont~nuously 

movement relative to one another; friction drives and irregularly varying the timing of the conhaving a slipping action and arranged to actuate tacts in a random manner. 

said bodies in a discrete time relation; and means 9. A switching device comprising. components 

55 including a system of differential gearing and provided with electrical contacts, said- compo- .

55 cams of irregular contours operatively coordi- nents being rotatable with respect. to each other 

nated with said gearing and with each of said for establishing a plurality of circuit connections; 

drives individually to aid the slipping action and a friction drive mechanism for each of said comto effect aperiodic movement of said bodies rela- ponents, and including means for separately and 

60 · tive to one i:mother. differentially operating said mechanisms to vary 60 2. A mechanism of the character described for the timing· of the circuit connections in a random' 

controlling the operation of an electrical system, manner. 

comprising.a rotatable commutator provided with 10. A switching mechanism, compnsmg relacontact elements and a rotatable switching device tively movable components provided with con65 operable with said elements for establishing a tacts for establishing a plurality of different 65 plurality of circuit connections; and means to circuit connections; means for varying the circuit 

effect a random operation of said system com- connections, comprising frictional drive m·echprising variable driving units· for operating said anisms operable variably with said components; 

commutator and said switching device asynchro- and means for changing the rate of moveme'nt 

70 nously, and means for differentially controlling of said mechanisms to assist in randomizing .the 

the operation of the units. circuit controlling operation of the contacts. 70 

3. A combination according to claim 2, in WILLIAM F. FRIEDMAN. 

which the last named means includes cams of FRANK B. ROWLE'IT. 

i_,