US992791A

US992791A - Wireless telegraphy.

Info

Publication number: US992791A
Application number: US28123405A
Authority: US
Inventors: James F Mcelroy
Original assignee: Individual
Current assignee: Individual
Priority date: 1905-10-04
Filing date: 1905-10-04
Publication date: 1911-05-23
Anticipated expiration: 1928-05-23

Description

J', P. MGELROY.

WIRELESS TELEGRAPHY. APPLICATION FILED 00T. 4, 1905*.

Patented May 23, 1911.

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J. P. MGBLROY. WIRELESS TELBGRAPHY.

. APLIcATIoN FILED 0:1124, 1905. Patentd May 23, 19111;

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Specification of Letters Patent.

Patented May 23, 1911.

Applieauqn :nea october 4, 1905. serial No. 281,234.

or received waves act upon each other with reference to the arrangement of the respective conductors or antennae. Figs. 2 and 3 illustrate the manner of connecting a sending or receiving station in multiple and in series respect-ively with the conductors or antennae. Fig. 4c is a diagrammatic illustration of 'the manner in which the waves y act upon each other when the conductors or antennae are arranged in the arc of a circle. Figs. 5 and 6 arev diagrammatic illustrations showing the connections with the sending and receiving apparatus respectively as em-A ployed with the antennae arranged as shown in Fig. 2. Figs. 7 and 8 are diagrammatic illustrations, showing the 'connection with the sending and receiving apparatus respec- 'tively as employed with the antennae arwaves-to a series of water waves extending outwardly in a series of circles from the point of disturbance, each one of my transmitting conductors would represent the center of a series of waves` of a given length and I arrange a line' of such conductors a distance apart equal to one-half of the wave length, so that every other conductor would be at the peak of the wave and the alternate conductors-each at the depression be designated as positive and the alternate ones, namely, those. at the depression of the waves, maybe designated asfnegative'. In

of the wave. The former set of conductors, ,namely thoseat the peaks of the waves, may

transmitting, each one of the. conductors will be the center of a yseries 4of outgoing electric' waves alternately positive and negative. In Fig. 1 I have indicated the results which will follow from the superposition ofsuch a series of waves from a series of conductors arranged in a straight line-coin.

aident with the line in which .itis desired to transmit the message. l

The positive waves are indicated by full lines and the negative ones by dotted lines. An examination of Fig. 1 will show that along a general axis coincident with the line in which the conductors are 'arrangedthe waves from the several centers of transmission will coincide, there being acoperation of all the positive conductors, sothat their effects are added together and there will occur a similar cooperation and addition of eii'ect at the negative points. This result'is due to the fact that thelength of the wave is so calculated with respect to the distance apart of the several conductors or, viceversa, the conductors are so spaced with respect to the length of the wave, that a positive wave transmitted from any one conductor as a center will arrive at the next A positive conductor at the right instant to coincide with the producing of a positive wave at the said next positive conductor and so on. Considering the superposition of these waves in a line atright angles toiy the axis of transmissionit will be manifesty that the waves willn exactly neutralize each other instead of coperating, there being at any given point'lalong such transverse axis an equal number of positive and negative waves as indicated by the full and dotted lines respectively. By this arrangement the transmission will be directed along the axis coincident withl the axis of the conductors and in no other direction, sincein all other directions the waves exactly l neutralize or interfere with one another as distinguished from their coperative 'eifect along the-axis of transmission. Similarly at the, receiving point electric waves of the i rightlength will combine their inductive,v

all the positive conductors and a downward electric current at all the negative conductors and by establishing the proper electrical connections between the conductors so. that the charges from all the elevated wires will reach the receiving apparatus at the same instant a current will be produced between the two sets of elevated wires that will act upon the receiving instruments.

The conductors may be connected either in series or in multiple. In Fig. 2 I have shown the manner of connecting the conductors in lmultiple. All of the

positive conductors

1, 3, 5, and 7, are connected to the same point a by means of conductors of equal. lengths and the negative conducto-

rs

2, 4, 6, and 8, being similarly connected by equal conductors to the point b. The instrument I will be connected in circuit between these two points a and b. It will be a transmitting instrument at one end and a' receiving instrument at thelother end. By making the .p connection tothe common points aforesaid 'of equal Vor like'character all of the positive conductors will produce their effect at the point a simultaneously and the negative conductors will likewise simultaneously produce their effects at the point b. Conversely the transmitting effects from a and b will reach the several conductors simultaneously.

When transmitting apparatus are used with the conductors vo-r antennae shown in Fig. 2, their connections may be made,l as an example, like those shown in Fig. 5. In this ligure, a and b respectively represent the teminals from which the conductors fv, o radiate to the respective antennae; c indicates the spark gap which produces the oscillations in the antennae, d is a condenser for providing the requisite capacity so that oscillations of definite frequency may begenerated, e and 7 are respectively a secondary and primary of an induction coil or transformer. for producing the alternating ycurrents/in the transmitting circuit, and the primary f of this transformer or induction coil may be included in the circuit with an interrupter g, a battery l1., and a sending.

key z'. y

In Fig. 6,76 indicates a suitable wave re sponsive device, such as a coherer, connected between the leads 'a and b. m indicates the coil of the relay, having an armature 0, and 'n is a battery for operating the relay in con nection with the wave responsive device is.

Suitable inductances or 4choke coils Z, Z arey inserted at each side of the coherer for pre-- venting the received oscillations from reaching the relay. The armature 0 is adapted to close a circuit containing a battery p, an indicator r, by which the signals are made visibly or audibly apparent. I do not wish `Z Z', the magnet m and battery n.

to be understood as being limited -to these particular forms of sendlng and receiving apparatus, for vany devices for this purpose known to the art may be employed.

In Fig. 3 the several conductors are cbnnected in series, the top of a positive con-- ductor 1 being connected to the top of the succeeding negative conductor 2 so that an upward impulse in conductor l will coperate with a downward ,impulse in conductor 2. The remaining conductors'l will beloonnected in like manner, the connection being somewhat analogous to a wave winding in the armature of a dynamo, the several positivey and negative phases of the waves corresponding to the alternate north and south poles of a field magnet and the several conductors corresponding to the induced wires of the armature. p

In my arrangement I prefer to insulate the transmitting and receiving conductors from the earth so.that they are independent .of the earths variable static charge.

The letter t indicates suitable insulating bases' for supporting the antennae, and which rest upon the earth or other surface s.

The transmitting andreceiving apparatus which may be used at H with the apparatus of Fig. 3 are indicated in Figs. 7 and 8. In Fig. 7 a and b represent respectively the' leads connected with the antennae, c indicates two spark gaps which are in series with said leads. d is a suitable condenser having the necessary capacity to regulate the oscillations produced in the antennae; e and f are respectively the secondary and primary of a transformer or induction coil, and in series with the primary f, an interrupter vg, sending key z', and battery d are ineluded. l

In Fig." 8, lc indicatesa suitable wave responsive device, such as a coherer, connected between theleads a and b', nected in parallel with this coherer but in series with each other are the choke coils The magnet m operates a suitable relay o in circuit with the indicator 7" and battery p.

In the arrangement which I have shown in Fig. l there will be not only a definite direction given to the transmitted message, but the system will also bepractically independent of any other waves of a different length, or waves of the same length coming from any other direction. It is not, however, absolutely perfect in the latter respect, since it is possible to `conceive of waves of shorter length arriving diagonally Vand of such length that their positivehand negative points will coincide with the respective conductors of the system, although their wave length is not the same as that for which the system is normallyadapted. In order to eliminate this chance of interference I may y arrange the conductors in the arc of avoir- Concle, as shown in Fig. 4, instead of in a straight line. By this arrangement there will be the same coinciding elit'ects in one specified direction which I have already described, as will be evident from an inspection of the figure showing the several positive fand negative waves super osed. upon each lother. The coperative e ect will be along a line parallel to a tangent to .the arc in which the conductors are arranged. This will be the axis of transmission, while on either' side of such axis the waves will interfere with and neutralize one another.' It is impossible, however, that any wave coming in a direction angular to the axis of transmission will lind the respective conductors coincident with the positive and negative points of the wave because with respect to such a wave the spacing of the conductors will lnot be uniform. In the arrangement of Fig. 4 a connection of the positive conductors in multiple withv one another may be provided for by wires of equal length brought to the center of the arc in which the conductors lie, while the negative conductors may be connectedA in multiple in like manner and the two centers of connection joined with the receiving or transmitting instruments, as' already described.

My invention is not concerned with the particular character of the instrument employed for transmission, or for receiving. I- merely indicate an instrument in Fig. 2 at -I connected in circuit between the points a and b and in Fig. 3 a similar instrument H will be connected at a point in the series circuit. These instruments will be ofl any kind suitable for exciting or producing electric waves'at the transmitting station and for detecting or receiving them at the re# ceiving station. Therefore, I have merely made a .diagrammatic indication of such in' strument. My invention is concerned with the relation between a series of transmitting and receiving conductors and the electric waves -transmitted from one to the other. What I claim as new and desire to secure by Letters Patent is:

1. In a system of transmission by electric 'waves, a terminal apparatus comprising a series of two or more antennae separated by a distance equal to one wave length of the transmitted waves, and electrically connected together, and aseriesof two or more transmitted waves, a similar series of an-v tennae insulated from the earth and separated by one wave length and arranged intermediate and at equal -distances from the antennae of the first series, and station apparatus connected in circuit with the respective antennae.

3. In asystem of transmission by electric waves, terminal apparatus comprising a series of antennae -insulated from the earth and alternating with a series of antennae also insulated from the earth, the said an.

tennae being located in the line of desired transmission and spaced apart substantially equal to one-half the length of the transmitted waves, and means for simultaneously exciting each series of antennae with electrical oscillations of opposite sign.

4. In a system of transmission by electric waves, a terminal apparatus comprising antennae insulated from the earth, means for producing a series of electric waves having their positive portions coincident and also having their negative portions'coincident in the direction of desired transmission but non-coincident in other directions, the electric instrument in circuit having' its leads connected with the ends of said antennae.

5. In a system of transmission by electric waves, atern'iinal apparatus comprising anl tennae, meansv for producing a series of electric wavesT having their positive portions coincident and also having their negative por-r tions coincident' in the direction of desired transmission but non-coincident in other di- J AMES F. MCELROY.

. Witnesses:

BEULAH CABLE, Wiiniaii: A. Momma., J r.