US1555633A

US1555633A - And malcolm s

Info

Publication number: US1555633A
Authority: US
Publication date: 1925-09-29
Anticipated expiration: 1942-09-29

Description

UHUOO nLl'lmlnLiUL. unnnuua L. BURCH ET ,QL

SECRET SIGNALING SYSTEM ATTGRNM Patented Sept. l29, 1925.-

UNITED STATES.

assi-:,633

Irarea'r orifice.

LYNDEN 'UxtUl-I, OF BELLEVILLE, NEW JERSEY, AND .MLCTJIWI 3f.. '.E-Alft-flll?, GES' `NEVI YORK, N. Y.

SECRET SIGNALNG SYSTEM.

Application med December ATo all 'w71 om t may concern.

Be it known that Wc,'LYNocN linnen and MALCoLM K, .lriunlrnnsn both citizens ot the United States, residing at Belleville, in the county ot' Essex and fiiatc ol Non' Jersoy, and New York city, in. the cminty Bronx and Stale of New York, respectively, have invented cert-.1in ncav and useful lui-I prorcinei'its in Secret frliirnalinr Systems; and we do l'icreby declare the following to be a ilnll, clear, and exact deyeription of the. iiirci'itif'm, snchV as will cnahle others skille-,fl in the. art to which it a'gijijafi'lans to niake and use the san-ic.

This inventioii relates io secret si/naling syst'enis such as telegrailili and telep ie tems', and is directed7 incre particularly, to. asysleni 'tor secret inl'crcoininnniration ha iwecn radio stations.

Systems tor acconiiplishing secret adio communication `by moans oi periodic' were length changes at the transmitting station. have heretofore been proposed, hut in each instance, so i'ar asoit has been ascorta-ined,

the arrangement has been such that IeitherA a comparatively simple receiving,` apparatus V,winch could be readily constructed and open ated by anyoncskllled 1n the art was capable Aof defeating the purpose oit' the proposed" system; or the receiving 'apparatus was so coi'njplicaled as to render vit iinpracticable for t tuning.,4 u l t, i

VLccordinic'r, to the former type ol arral'igge4 designed tooperate .on two ware lengths alternately; and the receivine' statica was provided with a. receiving' apparatus capable ofrespondingY to two Ware ,lengths siniul tancously. Receiving apparatus ot that characteris very rosy to construct, and it is therefore' a simple matter for Would-,be eavesdroppers to defeat the, purpose of such a. system. The Second type arrangement referred to is merely an extension of the 'y first, and diljl'ers therefrom only `in that a larger number ot Wave lengths were trans mitted in'seriatim. Receiving apparatus of the latter character was designed robe rc sposive to all of the severaltransmitted Wave lengtlis concurrently. Receivinglapparatas of 'this character, where a large man ber of wave lengths are employed, is extremely complex and'dillcnlt to adjust. In fact, it amounts practically to an aggroea- 1922. Serial No. @Hi8-QS.

tion' ot receiving stat-ions equal in number to the nunihcr oi' Wave. lengths employed. For emniplc` if y six vfarc lengths were employedA` it 'was necessary to provide re ceiving ai tmratus which was practical-ly cl'niivalen. to si*L separate receivingl stations, all ot which rsi c .nece saril) oinfratcd. simultaneously. lli'nh a cater number oit' wave lengths a ll nio'rc complet receiving eipiipincnt a' s olf coin-sc necessary. Those skilled in the maiiinilillaion of radio receivin; apparatus will reafclili' eppri-.ciatc the practical dillicnlig, in volvcd in tho operation of: such receiving equipment.

' 1t is accorl'lingjly the prii'ieipai object of the 4'presaiit invention to provide an ellic-ient secret signaling sy in, and more especially a secret radio signaling s: \'stcin, which is cmnparatirely sim-ple .in structure and 1nanipulation hat h igrhlj,v effective in accom plis-hing secret connminication.

In pursuanceof the iorogoing object 'a further object to provide means whereby niclzhanisn'is at two or more distantli1 separated stations which are not ii'iterconnected lnecllaiiically or electrically can be. operated and maintained in substantially exact syn- The invention resides, generically, in the. utilization of gyroscopcs or other equi l'aient mechanisms which are responsive in operation to thc roi ation of the earth for inain.- taining;` synchronizing' mechanisms or the like in synchronoiiis cooperation.

More specifically the principal. feature of the inycntirm consists in the provision of gyreseopically-controlh-d periodically changing signaling devices: at each of two or more signaling stations as, lfor instance, .radio sta'iic'ins.V nla-relij' the. several#stations are maintained in syiwhronous cooperativo relie tion and whereby sei-,ret communication may be maintained between the stations.

Asapplicd lo secret radio cmnmunication, the invention in its preferred embodiment contemplates the provision-at distantly scparated transmittingv and receiving stations of switching or other means f or period ally changing' the operating Wave length and 131 lll() exact synehronisin so thaiA the rcceiuirg s'- f tion is able to unintermptedj.-v receive in coming si nals on periodically changing 10 'stantly maintain its axis ofrotation parallel to vany plane in'space in 'which 4it may be Wave lengt 'is from the transmitting station.

,It is a 'Well-known phenomenon that a gyroscope having two axes oi rotation at right angles, if properly positioned with relationto the axis of rotation of 'the' eartli, will, in effect, make exactly one revolution in twenty-four hours aboutl one of. its axes.` rlfhis phenomenon is due to the fact that the gyroscope rotor when rotating tends to conwhen set in rotation, While thcrotation'of `the earthcarries the su' porting structure of 15 the gyroscope complete y around one of its axes once in the course of a complete revolu tion of the earth, or, in other. Words, once in twenty-four hours.. This slow rotation of the gyroscope about what will, for, convenience, be termed the secondary axis, is then -a function ofthev earths rotation, and is at the same rate. of speed irrespective .0f the place where the gyroscope maybe located.- 1 The present invention utilizes this gyruscopic phenomenon for controlling the opera- `tion. 'of duplicate Wave length changing switches at the .transmittin and receiving stations 1n such u waythat t e tuning of the l receiving apparatus is changed periodically in substantially exact Wnchronism with the 'periodic changesf-ofA operating jwave length `at the transmitting station.

Another feature of the invention' relates to -the means employed for Iinitially synchronizingthe receivingstation with the transmitting. station. This consists of` an arrange-v ment at the transmittiiwr station for periodicallygitrransmitting a liaracteristic tuning signal land' an arrangement attlie receiving station' for. locally duplicating the tuning signal or signals-in duration. and period,

butpreferably, not in tone. Both 'the incoming `and local tuningsignals may be heard at the receiving station when thetwo stations-.are not synchronized, but the ai'- rangement is suchthat 1when the two stations are synchronized the incoming and local tunjing signals 5ol tion is brought about through the medium therefore not capable of being distinguished from one another. -This initial synchronizaof4 an adjustable contacter forming a part of the wave ,lengthv changing switch at the re-` ceiving station.

, The invention is not limited in its utility to vradio si felling systems, but is equallyl useful in ot er ty' es of signaling systems as, for instance, 1n t e multiplex printing telegraph art, wherein 'a plurality of messages are transmitted over a line simultaneously, end in which systems the transmitting and receiving stations are, at present, maintained in synchronism by means of tuning forks.

The preferred embodiment ot the invention as applied in secret radio' signaling occur simultaneously and are i system is described in detail hereinafter and illustrated in the accompanying drawings Which form a part of this specification.

lith reference to the drawings,

Fig. 1 is a circuit diagram of a radio telcphone transmitter in accordance with the invention;

Fig. 2 is a circuit diagram of a radio telephone receiver `which is adapted to cooperate with the transmitter oi Fig. 1; and

Fig. 3 is a side elevation partly in cross section of a switching mechanism including a gyroscope adapted for periodically chang'- ing the operative wave length` at both the transmitter and receiver.

The transmitting station of Fig. 4l comprises an antenna ground circuit 1 including a loading -inductance coil 2, a generator of undamped oscillations A, and-a continuously 4operable Wave length changing switch B.

ment, a grid and a plate.- A. battery 5 supplies current through the rheostat 6 for heating the filaments of both tubes, and a direct current generator 7 is connected in the lilament-plate circuit for supplying space current to the tubes. A choke coil' 8 is inserted in thc filament-plate circuit for smoothing out irregularities in the current-from the generator 7. Condenser 9 functions as a bypass for high frequency currents in the lilament-plate circuit. The inductance coil 2 is common to both the filament-plate circuit. land 'the filament-grid circuit, and operates as a feed-back connection whereby the circuit is rendered oscillatory. The func-tion of thegrid condenser 10 is to negatively bias the potential of the grid.; and grid leak resistance 1l operates to prevent the accumulation of an excessive potential on the grid.

An interrupter -or ehoigipei` 12 is inserted in the grid conductor 10, but is normally" shunted oy switchl. The interrupter l2 is designed to interrupt the gridcircuit at a suitable tone frequency. for thepurpose. cfs transmitting audible tuning signals, as'will be referred to hereinafter.

The Wave length changing svvitch B,

shown schematically inpFg. 1 and in oonl y siderable detail in Fig. 3, comprises a coniii'iutator 14,hav1ng, 1n this instance, nine insulated metal segments S, to S, inclusive, and three smaller segments T1, T2 and T8, which may be conveniently referred to as. timing segments. v

Referring to Fig. 3, the commutator 14 is rigidly scoured to shaft 15, to which is also secured a pinion 16. Shaft 15 is driven by gear 17 through the medium of the inter-l mediate gear 18 and pinion 19. A suitable gear speed ratio between gear 1'? and pinion 19 and likewise between gear 18 and pinion 16 is lzO, and the resultant ratio between mounted on sha:

mames gear l and pinion 1 6 is 1:1600. Gear 17 is riginflly Secured to Siria-.lit 20, which is lJoiecl at its eii'il to 'form a ibeaiing for 'shaft l5 which is joui-nalecl therein.

Ten metallic. eoliecfos 'sings 21am shown l5. These are., of course,` insulated from each other and 'from ilie shaft Each 'ofnine of iliese collecte? rings is individually coriiiele jo a segment 51, S2, etc., and the remaining colleetoi" is conneoteci to the timing; segments TM and Ta in parallel. These connections are noli showmvbut -itwill be underelioocl that suitable conflueoi's for this puifpose may lie readily'provided, Y

Shaft 2O is jourcnalecl iii llieaiing and is secured yco the rotor ying, Q3 ofc' the gymscope. Shaft and the bearing .Qtizfl 24. which is joul'naledl iii beafiiig; 5./ are coax 'with what was .referred to lieireinbeloire :is

the secondary axis of rotation e. the

.,i'ies the yolci.

ence letters A pair of electric moioi'hA amil 27 llave 'their armatures mounted on a Shall, 128, mi which .is also mounted the gyroscope rotor* 2i). Shaft 28 is .iouiiialofl in bearings 3() aiiil 31, forming a peil oli the ioioi ling 23. ffl pair of collectoi xrings 54: are iiio'vided :for effecting electrical' oon'neolioi'ia io the

motors

26 and 27.

The entire mechanism. of the gljyioscope angl wave length changing' svi'iieli so fai" ,desoribed is carried 'by the seiii,ioiieulaii yoke Wl'iicll in. turn is mounted. om lio peiosial and is aiigulai'ly ailiusiiabie thereon. as may be iifilelieil from the Calilii'ajo rm lie yoke.

lfm .fffs-.ordanoe with one of tiie Well-i nown .lali's governing the action of @woei-oyes, ilio irolor 59, when iotalpiiig it u. froiieilei'able vomi. wiil teiii :flnorigl'y llo iiiaiiilaiii its axis; of rotation iiaiallel to any p 11C AL12 which it may liaii'p i to be iiiitialli7 il. H theo the s l; il

tely

iii-,e mi; "plane wl ie ilio ifa 2 ami,

iii

iitii'o pia* n olea ei a oi pa L .i iis action oi? die gyra scope, bomma-'eig tool; @ppal iii, lo 'lliif oli serrer, auf? for all Liaeioal purposes; il; :mav be said fhalz the ring QB rotates about tile axis R---R once 'for each revoliiti of itl e earth. ll- 'ifolloi fear r 'lien that einem a 1v1-tio oi 1.1.1600 interposed between tlm Condoom rotor iiiiggj t2?) and 'the ooiiiiuiitzator 145 the latter wi l rotaie ai the. rate o'E 1.600 revolu- Lions in wrenty-:loui hooi-s or 1.111. R. P. M., and since libe vommiitatoi' iii this instance is provided with nine segments, there will be SlXljllzQQQ, oir approximately ten wave length changes pei' minute.

On Liuc-omit of the gear ratio employefl, a Ivory consicloifalile torque is regioire-o of eoiigiiieiable proportions would be requiifeal to Supply auch :i torque. in oitfiei 'to malte it possible to 'utilize a relatively small gyroscopo, it is Lnopoeo to Lise an auxiliaiy driving motor as, loi.l instance, a Spi-ing' i'iioiioi' 3&1-, which engages gear 17 through inlie meifliiiii oi' pinion 35. The ai'ixiliaiy iiiolif, "l i5 piel'eifabl-v designed lo ssp'ily eiioxgli iioi'celo l'lie L ,iii .lT to bnl ance llio md eo i-iial; l'flie gyioscopeiias prac 'lziizally no mari to oai-ry Time the size olf tio.: g iroscoiie may lie ieiilui-eii to a minimum and. ite function iiiia'y 'oe ibstaiitially that of i; "oi'oiiioi only. W iii@ lliv auxiliary Iiioloif lY ver); desirable, it door! not' emiiiiveiitioi'i.

oiilao. wiper arm is insulativel); mired to lle f fieeve 37', Wliii'rli is bored to oeife il righi, iiaiizl emi opii' il?, l5. iailei v vided with knob 31'" whereby the Contact Wiper ajiii'x 3G may be iiialiiially rotated velaiive lo the commutator Exif. `This provision im' afljiieiiog 'Elije ooii'tiwl; ii'ii'iei" ai'iii is use l'iil i'iioi'i; particularly at llie receiving A:#iatioii for' e-:liieetiiig ixiiiial symzlioniem. but if, muy also lie employed to gooii aclvaiiage ai; the ti: Jmitting Station,A aitliough 'it isi not inilihiiensalile there.

llel'ei'x'ing again izo Figli. 1 ilse infinis-:mitiiiiisl' wow.: length alia'ogc are ullwflml by wrioclic'ally iwiijving lli@ i'ezirr'lai'1r :e ol lie zu teiiizi g'oiii'icl Gironi imrl l`oi lliie piiiposo is 3Q to l? iiioliisivo ol? (lii'i'ei'ml, oa'paritios may be f'ein'eiiivntly utilized. lim-li ol {lieu-se minions i:` corina-uuml iliii-,iiggjli .ii illude oi'. so'ilili ibi izo ai. ooiiimiiln im' zvi'giiwiii. lTiH i.. Fit, ilrqiioiii'i'lji'. lliewo voiiiim'limis laying' malle 'tlwoiigli tlw in liiiiii o1' Lei)ii'uponiliiig ooiloiloi' i'ii f-: il .3) :mil suitable lii'ii.-:lu ii'liicli :1ro noi; shown. nmiiluciioi' lll) esiablislxos a venom-lion lieiii'wii Contact wiper arm fil' :imi indocmim son '1.5. li Lilo invention im :.i'iiiiifril to milio telephony, any :iiiiialile iiioiliilziloi' oi' system. of modulation as, lm' iiislanieT a magnetic iiioiliilriloi' 5l), may im iofai mi in the Limoni` inail ol? ifi@ antenna ground circuit ovgelliei' with a iiiioifopl'ioiie 5l, which would ordinarily lie provided in ci'mjuiiction tliei'eWi-tli.

l `i-om the foregoing description it will be quite readily undeisioodtlmt in .opel-ation iiw con'iiiiutatoi lai. is i'olatinp; at. a uniform spinal miller the Coni-'ol oi" the gyroscope and to turn the shall.; 2li. zuid a gyioscope i i; jouilialefl therein, amil is pifo-.

Therefore,

that one end of the contact wiper arm engages the segments S1, S2, etc., successively,

thereby connecting the condensers '39 to 4:7 in seriatiin, and accordingly changing the operating wave lengt-h periodically. In normal operation switches-48 and 13 are set in the positions shown.

It is, however,- necessary to initially synchronize the receiving station with the transmitter, and for this purpose the thi-ee tuning segments T1,'T2 and T3 are provided. These timing segments may be connected into the antenna ground circuit in series with condenser 53 by throwing switch 4.8 into a position wherein switch blade 52 engages its fixed Contact. With switch 48 thusthrown into its off-normal position, it will be seen that for each revolution oi' thecoinniutator, three impulses are transmitted into the ether, one 'for each segment T T2 and T3. If switch 13 is open, the high frequency Waves constituting each of these three inipulses are chopped into audible frequency groups, as is sometimes done in the case of undainped wave tclegraphy.

The reccivingstation shown schematically in Fig. 2 includes a tuningswitch C, which may be structurally the same as the wave lno any other suitable type, as willbe readily apparent. vThe antenna ground circuit .includes a vari-able'inductance coil 56, and:

may' include a second lcoil 57 which functions in connection with thc operation of initially synchronizing the receiving station with the transmitter. The tunin of this receiving circuit in accordance with the pe riodic chan es of wave lengths' transmitted isaccoinplis ed by connecting condensers 58 t0 66 inclusive, in seriatim, 'in parallel with the inductance coil 56.

Each of the last-mentioned condensers is connected through a blade of switch 68 to one of the segments S1, S2, etc., and it will be readily apparent from an examination of the circuit that each/'ot these eondensers is brought into operation when'its correspond ing segment is engaged by the contact wiper arm 69'. The capacity of condenser 70 ia suitable fortuning the circuit ior the recep.i l

tion of the previously-inentioned tuning signals, 1n order to receive these sifmals, switch 68 is thrown out of the normal position in which it is shown into its oiinornial position, wherein switch blade 7l engages its fixed' contact and whereby condenser Z0 is connected in circuit. `The' periodic tuning signals from the transmitting station may then be heard in the telephone 72. For the purpose ot synchronizing the tuning switch C with the wave length changing switch D at the transmitting station, an auxiliary buzzer circuit E is provided at the receivingA station. This comprises a buzzer 7B having an audible tone frequency, a suitable inducta'nce coil T4 in inductive relation to the coil 57, a. condenser 75, and a battery or other source ot current 76. A switch '77 is provided for closing the buzzer circuit.

With the latter switch closed, the buzzer.

circuit is extended to the tuning segments T1, T2, T3, and thence through the contact wiper arm, and is closed each time the contact wiper arni engages one of the tuning segments. Since there are three tuningscgniente, the buzzer 'Filis operated three times in succession for each revolution oi' the conimutator i4. lt will now be quite' readily apparent that it' the wave length, changing switch B at the transmitter and the tuning switch C at the receiver arc not synchronized, both the incoming tuning signals and the locally generated tuning signals which are set u i by the buzzer 73 will oe heard in the telephone 7 2. By turning the knob 537 (sec-Fig. the contact wiper anni 69 at the receiving station may be rotated until the local tuning signals and tbeinccming tuning signals are exactly blended. lNhen thus ada justed, the two stations will be. in. substantiallycxact synclironisin, and the 68 and 77 at the receiving .static-n and switches d8 and 13 a't the tienen)ittng` staf The detector circuit D comprises a three l element vacuum tube 7 8, a. ilanient battery 7 9, a filament-plate circuit battery 80, a grid condenser 81, a grid leak resistance 82, and a ticklcr coil 8B. This is a simple circuit of the well-known regenerative type, and it is thought that its operation will require no explanation.

An attempt has been made herein to iilustrate and describe this invention in its sini` plest terms. It will no doubt be recognized by those skilled in the art that in practice it might be'expedient to elaborate somewhat upon the circuitl shown. For instance, it will be readily ,recognized 'that more than one adjustment might be desirable at both the transmitter and receiver. This would probably require one or more additional. commutatore and associated contact wiper arms on the shaft 15 ateach station. Furthermore, the receiving station would in all probability be iprovided with vtwo or more stages of ampli "cation,

Means other than gyroscopes which are capable ot utilizing the rotational eii'ect of the earth for the purpose of maintaining synchronism as, for instance, a pendulum, are considered Yfor the purpose of this invention as being' equivalent tc a gyroscope.

Many modifications oi' the present inven tion will be readily. apparentto those skilled switches enemy,

nwaees in the art, and itis not desired that the in vention be construed as limited except byV cluding a gyroscope for mutually synchronizingV the operation oi -aid transmitting and receiving apparatus.

2., In a signaling system, signal transmit tino' apparatus, and a gyroscope 'for conA trolling the operation of said transmitting apparatus.

3. `In a signaling system, receiving appa ratus, and a gyroscope for controlling the 4operation of said receiving apparatus.

4. In a signaling system, signaling appa 'ratus, and means for periodically changing; the 4operating characteristics of said apparatus. said means including a gyroscope.

5. In a signaling system, a high frequency transmitting station having means .for periodically changing its operating frea high frequency receiving station for cooperating with said transmitting station having means for periodically changing 'its operating frequency, and means controlled by the rotation of the earth :for syn' chronizing the operation of said first and second means.

6. In a signaling system, a transmitting station, a receiving station, and means controlled by the rotation of the earth tor maintaining said stations in communicative relation toeach other.

7. In a vi'ave signaling system, a high frequency transmitting station, a high frequency receiving station, means atgeach of said stations for periodically changing their respective operating frequencies, means for initially syncl1ronizing.,said receiving station with said transmitting station, and 'means responsive to the rotation of the earth for controlling both of said first-mentioned `means whereby said stations are maintained in synchronism. y

8.A In a wave signaling system, a high tre` fluency station, means tor vperiodically' changing the operating frequency ofsaid station, and means responsive tothe rotation of the earth for controliing the operation et said first means.

9. In a signaling system, a transmitting station, a receiving station, said stations being adapted 1o cooperate only when one is operatively adiusted with respect to the other. moans ior continuously Varying the operative adjustment ofsaid stations, and controlling means for said first `means whereby said -stations may be' continuously maintained in cooperative adjustment.

10, In combination with 4signaling apparatos, means operable for controlling the operation of said signaling apparatus in a predetermined manner, and means responsive to the rotation of the earth for maintaining the operation of said lirst means at a uniform time rate.

11. In combination with signaling appa ratas, means operable 'torcontrolling the operation ol said signaling apparatus in a. predetermined manner, and means including a gyrosoope t'or maintaining the operation of said first means at a unitorm time rate.

.l2 In combination with signaling apparal-vus, means operable for4 controlllng the operation ot said signaling apparatus in a predetermined manner, and means respon sive to the rotation oi' the earth for controlling the operation of said firstmeans in accordance with a predetermined time factor.

13. In a signaling system, signal propagating means, means for changing the character ot the propagated signals in accord ance with a predetermined time factor, and means responsive to the rotation of the earth for controlling said nrst means in accordance with said time factor.

14.` In signaling system, signal prepa" gating means, means for changing the character ot the propagated signals in accordance with a predetermined time tactor,'and" means including a gyroscope for controlling said i'irst means in accordance with said time factor.

15. In a signaling system, high frequency signal propagating means, means for chang ing the frequency of the propagated Signals in accordance with a redetermined time factor, and means inclu ing gyroscope for controlling said irst mesns'in accordance with said time factor.

16. In a signaling system, a plurality ot high frequency stations, means for periodically varying the operating frequency of said siations, and means responsive to the rotation of the earth for synchronizing the periodic variations o said stations.

17. In a signaling system, a transmitting station having means for generating and. transmitting signaling Waves of a plurality of frequencies, a switching mechanism at said v'transmitting station .tor periodically changing the frequency of the signaling ULJ KBRVKH Waves, a receiving station having means for receiving and indicating the signaling waves from said transmitting station, a switch mechanism 'at said receiving station `tor periodically changing the tuningvof said receiving means, said switching mechanisms IBUVIUI Waves, a receiving station havingr means for Lib i receiving and indicating the signaling wares from said transmitting station, a switching mechanism at said receiving station for periodically changing the timing oit said. receiving means, said switching mechanism when operated in' synchronisiu being adapted to maintain said stationsin communicative adjustment, and means including a gyroscope at each of said stations Jfor maintaining said switching mechanisms in syn-- clironisin.

19. In a signaling system, a transmitting station having means for generating and transmitting signaling ivaves of a plurality of frequencies, means for periodically changing the frequency of the signaling receiving and indicating signaling waves from said transmitting station, means for periodically changing thetuning of said rer ceiving station in accordance with the :tre-

quency changes ot' the signaling Waves transmitted from said transmitting station, means'atv said transmitting station for transmitting a timing signal, and iiieans at said receiving station for adjustiinf. in vaccordance with said tuning signal, said means for periodicallyr changing the tuning' of said receiving station.

20. In a signaling system, a high 'frequency transmittingr station, means continuously operable during the operation ci said transmitting station for periodically changing the frequency of the transmitted signals, a receiving station comprising high frequency signal receiving1 apparatus, means continuously operable during` the operation ol' said receiving station for periodically changing the tuning of said receiving anparatus whereby said receiving' station may he 'maintained in opt-iatirc synchiouisin with said ti'ansn'iitting station, means at said transmittingr station for tansniitting a characteristic tuning signal at regular interv is. and means at said receiving' station for synchronizing said second-nicntioncd means with said first-nientioued means, sail s vn hroniziiig means being oncrahlc in con-- jun'rtion with said tuningl sgi'nn'l.

1. ln a signaling system. a high frequencytransmitting station comprising s :reir er Ator ot high frequency cogitinuouslv 'ioei'ahle iici'iiuuntion. switch1 ciyrcuit connections between said generator and said permutation switch wherein' said switch is adapted lo inriodicnllv change the ope atingfrequency ol said generator; and means responsivel to the rot ation ot the o'ai'th for maintaining thc oi'ierntion oi' said ierinutation switch suhstantially constant..

In u signaling system, a high frequensigi'ialing naves` a` cyl transmitting station comprising a generator ot high frequency signaling` wares, a continuously opcahle pcrn'iutation switch, -circuit connections between said generator and said pernuitation switch whereov said switch is adapted to periodically change the operating frequency of said generator, and means incliuling a ri'yroscogie ,For maintain ing' the operation of said pei-imitation switch substantially constant.

The ci'iinhination with a continuously movable switching device of means including a gyroscope :tor maintaining said device in operation at constant speed.

2li. The combination with a continuously movable switching device of a gyroscope having a major axis of rotation and a secondary airis of rotation, and ineens responsive to the. rotation oit said gyroscope on said secondary axis oi", rotation 'for maintaining said switching devicein operation at constant speed.

25. In coufihiiuition` a switching mechanism having a fixed contacting nicinlier and a movable contacting niemlier. a gyiosconc so disposed with. respect to the axis ot the earth that it will rotate on one of i relatively to the earth at a uniform snee L ndeiit upon 'the rotation ont the earth. and means for utilizing said rotation oi' the, gyroscope for imparting a uniform increment to said nio 'able contat'tine` inen'xher.

2G. in a s` 'naling system. a high frequency transmitting station comprising ineens for generating high lrequerny signaling Waves. a 'permutation switch nt said transmitting station for periodically' changing the oiieiatini iiequeiu-y' ot said generating means, said switch including; moans' ed for transmitting; cha, tic. tunic nais at regular pradet rnaiiieti interi/:i receiving station comprising." means ttor res ceiving and indicatfuo; the sigiuilh" from said transmitting slzitimi. a. permutation switch at said i' cciri station for periodically changing the timing at the receiviiinT incaus tl'ui'cut in synchronisin with the changes in operating frequency' at said transiniitiiul station. said inst-inentioncll 'permutation switch including nicaiis for in.- ilicnting' synriiionisin 7oetween sait-l .steth-un in accordance with said tnniuii ouais.

2T in n. Hiszualiuyu retenu n hugh 'i'eoinuci' transmitting station. :i high ircigiieucy rcceiring statioin :i .wuitiuuously movable switching mechanism at said transmitting station for periodical-li changing the operatingl frequency thereof. a continuously mov- :ihle switching mechanism at said receiving station for periodically changing the tuning` ion,

llt)

oit receiving' station in sliiichronisniI acteriste tuning Signals at regular prede termined interves eensolmnt with the periedc frequency changes at seid txansmi.- ting station, e local souree of tuning; signals comprising a circuit and source of eurrenf4 at seid receiving station, seid swichng mer ml nism ai; Said receiving staton being operable to close the circuit of said oea source 'et predetermined intervals and durations eer responding with the intervals and durations ef the transmitter' tuning signals, means for adjusting the switching mechanism at' seid 'receiving station for efeetng initial symA In testimony whereof 'we e'x 'mu' signa? tures.

LYNDEN v l IVMLTLJCULM l. PARKEHJRS'.