USRE12141E - Reissued aug - Google Patents

Description

No. 12,141. I nmssunn AUGJ4, 190s;

J.S.ISTONY E. APPARATUS FOR SELECTIVE ELECTRIC SIGNALING.

APPLICATION FILED JULY 11, 1903. v

35 it may render such circuit resonant to the'de- UNITED, STATES JOHN STONE STONE, or CAMBRIDGE,

Reissued. August 4, .1908.

PATENT ()FFICE.

MASSACHUSETTS, ASSIGNOR ,lO THE STONE TELEGRAPH AND TELEPHONE coMPA Y, or BOSTON, .nAssA CH USETTS.

APPARATUS FOR SELECTIVE ELEGTlR'IC SIGNALING.

SPECIFICATION forming part of Reissued Letters Patent No. 12,141, dated August 4, 1903; Original No. 714,834, dated December 2, 1903. Applics-tin for reissue filed July 11, 1903- Serial'No. 165,539.

To all whom, it may concern.-

Be it known that I, .ToHN STONE STONE, a citizen of the United States, residingat Cambridge, in the county of Middlesex and State of Massachusetts, have invented certaingj'iew and useful Improvements in. Apparatus for Selective Electric Signaling, of which the following is a specification.

My invention relates to the art of wireless [0 or space telegraphy-c'. a, to'theart of trans-- mitting intelligence from one station to another by means of free or unguided electromagnetic signal -waves or waves which are developed byproducing electric vibrations X5 in an elevated conductor, preferably verticslly elevated, and which are not guided to their destination by wires, as'in the system of telegraphy most commonly practiced today. Th'eobject of the present invention is to 2-; .realizefa system in'which the transmitting-- stations may selectively transmit their sig nals each to a particular receiving-station simultaneously or otherwise without mutual. interference. Itis also the object of the invention to provide means whereby each of a plurality of transmitting and receiving stations in such a system may be enabled to selectively place itself in communication with any other station to the exclusion ofall. remaining stations. It is further the'object of the present in-' vention to so construct and proportion the .electrorec'eptive device with reference to the receiving-circuit in which it is included that sired frequency. I

"The fundnmental or underlying principles of the present invention are fully described iuan application-for United States patent, 49 Serial No. 4,505, filed by me February 8, 1900, and the present invention is, moreover, tributary to an appllcatiolrfor United States patent, Serial No. 44,384, filed by me January 23, 1901. The present specification describes and claims a specific form of the broad inventions described andclaimed in the aforesaid applicationsSerial Nos. 4,505 and 44,384. By. my invention the elevated conductor of the transmitting-station is made the source :to repeat the same here.

50 of signalwavesof but a single frequency,

\ and the translating apparatus at the receiving-station is-caused to be selectively responsive to signal-waves of butasingle frequency, so that the transmitting apparatus corre 'sponds to a tuning-fork sending but a single musical tone, and .the receiving apparatus corresponds to an acousticresonator capable of absorbing the energy of that single musical tone. only. When the apparatus at a particular receiving-station is made resonant to the same frequency as that of the electromagnetic waves emanating from a particular transmitting-station, then this receiving-station will respond to and be capable of selectively receiving messages from that particular transmitting-elation to the exclusion of messages simultaneously or otherwise. sent from other transmitting-stations in the neighborhood which generate electromagnetic waves of other frequencies. Moreover, by'-7c my invention the operator at the transmitting or receiving station mayyat will adjust the apparatus at his command in such a way as to place himself in communication with any one of a number of stations in the neighborhood by bringing his apparatus into resonan-cs with the frequency employed by the station with which intercommuuication is'desired. I 1

Having thus broadly described the nature .80 and objectof the invention and having given at some length the electrical principles upon which it is based in the hereinbefore mentioned applications, Serial Nos. 4,505 and 44,384, it will suiiice to give a brief statement of the electrical operation of the apparatus to be hereinafter more fully specified. At this point reference may be conveniently made also to the specification of an application filed by me August 2, 1902, Serial No. 118,048, whcl ein are again set forth at length the principles underlying my system of space telegraphy,-of which the present invention forms a part, and it is not deemed necessary The details of the present invention may best be described by making reference to the drawings which accompany and form a part of this specification.

The same characters, so far asmay be, rep roo resent similar parts in all drawings.

In the drawings, V represents an elevated conductor or vertical oscillator.

.M M M, M, are induction-coils or transformers.

L L L and L, L, L", are auxiliary induc anc'e-coils. 1

O C C" and C, C, C, are condensers. I B is a'battery in Figure 2, and 7 is a bat tery in Fig. 4.

K is a coherer. I v

Ris a relay in Fig. 2, and 6 is a relay or sounder in-Fig. 4.

' P is a Plant battery or condenser of large v capacity.

E is an earth connection.

Fig. 1 is a reproduction of Fig. 12 of-the drawings of case Serial No. 4,505and case Serial No; 44,384, above mentioned. It is a diagram illustrating the connection of a condenser-telephone at a receiving-station.

Fig. 2 is a diagram illustrating the application of a condenser-receiver to a system whereby several receiving-stations associated with a single elevated conductor may select? ively receive the energy of electromagnetic signal-waves of ditferent frequencies, each in a particular electro receptive or translating device, to the exclusion of the energy of electromagnetic waves of ditferent frequencies.

; denser-telephone receiver used as a tuning-- .condenser in a resonant receiving-circuit.

. Figs. 3 and 4 are diagrams illustrating the tuning-condenser of a resonant circuit used as a receiver. Fig. 5 shows a form of. the well -known con- With reference to Fig. 1 attention is calljed to the fact that in the specification and drawings ofmyapplication Serial No. 4,505, above mentioned, it was-pointed out that. although f a coherer had been shown and described as a means of detecting the presence of oscillations in'a receiving-circuit, pnder which=circumstances it operated as a telegraphic relay to control the local-battery circuit, in- 'cluding a electrotranslating' device, yet any other suitable electroreceptive device might beemployed to receive a signal-as, for example, .-a condenser-telephone. It was furtherlpoiuted out that when such a telephone was employed as a receiver its capacity might be the eapacityby which the receiving-circuit of which it formed a part was attuned. In Fig. 1 the circuit of which the primary coil Ifforms a partisconnected either conductively or inductively with the elevated conductor at the receiving-station, all as more fnllyfdescribed in thecase of applications above referred to. In the circuit ()"LI,',;I, is the secondary of the coil M, of which I is "the primary. The coil L is an inductance-coil and adapted to supply the necessary auxiliary inductance tuning the circuit C L I,, and O is a condenser whichserves both as an electro receptive or translating device and also the figures of my telephone receiver 9. 4, the armature 5 is fixed, and the armature frequency as thebranch C, L, to the circuit C, 'L", M',, which is made resoas a capacity by which the circuit C L I, is made resonant to the desired frequency.

In Fig. 3 is shown one form of the translating device, wherein the light from the lamp 1, reflected by the mirror 2 on the moving armature 3 of the tuning-condenser O,, records the movement of said armature on scale 4 when a current flows in the circuit M, L",..

In Fig. 4 the movable armature 3 closes the circuit of relay or sounder 6 by making contact with the post 9'. This local circuit is supplied with anydesirable amount of energy from the battery 7 by the connection at its terminals to the resistance 8.

In Fig. 5 the condenser-O", is shown as forming part of the well-known condenser- Here, as in Figs. 3 and 3 is movable.

In the operation of Fig.1 electromagnetic waves impinging upon an elevated conductor (not shown in the drawings) developelcctrical oscillations in the associated coil I of the induction-coil M. The energy of these oscilla tions is'communicated to the circuit C L 1,,

which is made resonant through the capacity of the condenser C and inductance of the coil L to the frequency of the waves the energy of which the receiver 0 is intended to receive. I i

In the operation of thereceiving-station shown in Fig. 2 electromagnetic-waves ot' a given frequency impinging upon the elevated conductor V develop therein corresponding electric vibrations of like frequency. If the frequency of these-vibrations be that to which the branch circuit C L M is made resonant,

the energy of the vibrations will'be' received in that branch to the exclusion of thebranch G, L, M,, which is made resonant to a different frequency. The energy so received in branch 0 L M. is communicated, by means of the induction-coil M, to'the circuit C M L. M, which is made resonant to the same frequency 'as' the branch circuit C L M, and thence the energy is communicated to the circuit C L" M, which is likewise made resonant to the same frequency as that of the branches 0 M L M and C L M. The energy so received in circuit C" L",M" operates an elect-r0 receptive or translating device, (indicated at K.) It the electromagnetic waves impinging upon the elevlatedconductor V be of the frequency to which the branch circuit C, L, M, is made resonant, the energy ofthe resulting .vibration in the elevated conductor V will be received in' that branch to the ex--.. clusion of the branch 0 L M, which is made resonant to a dilTerent frequency. The energy so received by the branch 0, L, M will be communicated to the'ci'rcuit C, M L, M,, which is made resonant to the same M,, and thexi'ce nant to the same frequency as the circuits- C',*M,.L, M and 0, L M Energyso re- 1o 'rent.

t5 the circuit B R M L K.

current through the relay R.

its normal condition of high electric vibrations in said circuit.

5 minimum.

ceived causes. the operation of an electro. receptive or translating device indicated at 0 Iu'the circuit 0', L M, the element '0", serves both as an electro receptive or 5 translating device and 11s a tuning-condenser,

by which the circuit O L M, is made resohunt to the desired frequency. It is actuated by the current developed in its circuit, utilizing therefor the potential energy of the on r- This element will be hereinafter more fully. described. When electric vibrations are set up' in the circuit M L O of Fig. 2, the coherer K is cohered. The battery B is thereby permitted to develop a current in The function of the Plant battery or condenser P is simply to provide a low impedance or short circuit for the electric vibrations, while preventingthe battery B'from normally developing a This relay by its operation may cause a telegraphic sounder or other telegraphic receiver to respond, and they may also set in motion a tapper or decoherer, by which the coherer is restored to resistance.

- The electro receptive ortranslating device shown at 0 Fig. 2, is primarily a tuning condenser for the circuit C", L M}; but it also serves to make evident the presence of It consists of a fixed armature or electrode and a movable armature or electrode. It electrical yibrations be of the frequency to which the circuit is made resonant, the electrodes of C,

5 Will be at a difference of potential many times greater than the induced or impressed electromotive force. This difference of potential will cause an attraction between the armatures of C", and will cause the movaule 4c armature to approach the fixed armature.

This motion may be utilized to close a local circuit, and thereby operate a telegraphic relay or sounder, or it may be caused to deflect a beam of light reflected from its surface.

5 The normal capacity'of C is determined by the condition that it shall serve to tune the circuit with which it is associated, but leaves the dimensions of its armatures and their separation undetermined. in order to get the maximum sensitiveness in the instrument, the separation between the opposing surfaces of the armatures is made as small as practicable, and consequently, therefore, the area of the armature-shrfaces is also a By these N10; is the entire potential energy of the vibratory current in i l l l i i j i i the circuit C L", M is inade available to operate the electric translating device, and since the armatures are very close to each other the rate of change of the energy produced by the motion of the movable armature is at a maximum. The available force to produce this motion is thus made as great as possible.

In constructing the various parts of the apparatus shown and fication there is great latitude as to the cial forms that may be given them; but it must be remembered that when a circuit is to be made resonant and itis desired to gain a high degree of resonance both electrostatic and electromagnetic hysteresis must be carefully excluded from the resonant" circuit. For this reason all iron should be excluded from the coils in the resonant circuits and solid dielectrics should not ordinarily be employed in the condensers. These injunctions apply to the construction of circuits made resonant to very high. frequencies, but not with the same force to the construction of circuits to be resonant to low frequencies. Another precaution to be taken in the construction of the apparatus included in the resonant circuits When very high frequency currents are employed is that conductors between Which there exists considerable potential diilerence during the operation of the apparatus shall be kept as far apart as practicable, because of the excessive displacement currents which tend to flow in the case of high frequencies. For this reason I so design the coils used in the resonant circuit that their potential energy is small compared to their kinetic energy when supporting a current of the frequency to which the resonant circuit in which they are included is made resonant. In this way the frequency of the gravest of the natural modes of vibration 0!": the coil itself is made verygreat com' JOHN STONE STONE. .tVituesses:

CHARLES C. KURTZ, ALEX. P. Buownn.

descrihed in this speci- .1

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