US933018A - Telephone system. - Google Patents

Description

E. R. BRODTON.

TELEPHONE SYSTEM.

APPLICATION FILED JUNE 29,1908.

Patented Aug. 31, 1909.

Wihwouo UNITED STATES PATENT oEFIo EDWARD ROBERT I BRODTON, OF MOBILE, ALABAMA, ASSIG-NOR F ONE-THIRD T0 GEORGE Ha FONDE AND ONE-THIRD T0 ERNEST E. WAGAR, OF MOBILE, ALABAMA.

TELEPH NE SYSTEM.

Specification of Letters Patent.

Patented Aug. 31, 1909.

Original application filed November 19, 1907, Serial No. 402,856. Divided and this application filed June 29, 1968.

Serial No. 440,899

To altwhom it may concern:

Be it known that I, EDWARD R. BRoDroN, a citizen ofthe United States, residingat Mobile, in the county of Mobile and State of Alabama, have invented a new and useful Telephone System, of which is a specification.

This invention has reference to improve ments in telephone systems and is designed for use more particularly in connection with a wireless railway signal system, for which I have filed an application in the United States Patent Office on November 19, 1907, under Serial No, 402,856.

the following In the aforesaid application for patent,-

there is shown and described a signal system Wherem each train and preferably the engame of the tram carries a wireless signal outfit comprising a sending set by means of which'impulses are sent out continuously and automatically in the form of two or more overlapping trains of waves preferably of ditferent characteristics. The receiving apparatus on each train and-preferably on the engine thereof is capable of responding to the propagated trains of Waves coming from a distant point so as to actuate certain signal devices, and ultimately, if need be, cause the actuation of, train controlling devices so that the train is finally brought to a standstill on entering the danger zone. Under these circumstances the engine man is apprised by the stopping of the train or otherwise that there is danger ahead or behind as the case may be, but of thecharacter of the danger he has no information. To remedy this defect the present invention comprises a telephone system operating in con unction with the signaling system and utilizing a portion of the signal apparatus.

In accordance with the present invention the telephone system is designed to be used only when the train is at a standstill and from a consideration of the following detail The invention will be best understood descriptiontaken in connection with the accompanying drawing forming a partof th s specification, in which drawing there is shown a diagram of so much of the railway signal system as is deemed necessary for the understanding ofthe present invention, and in conjunction therewith there are shown the electric circuits of the telephone system at one end only of the complete system.

Inorder that the relation of the telephone system to the signal system may be fully understood the said signal system will be first briefly described.

Each train carries an aerial 1 which is' preferably mounted on the engine and III the following description it will be assumed that theentire apparatus is mounted on the engine although it is evident that may be mounted upon any part of the tram. Gonnected to this aerial is one side of each secondary of two Ruhmkortf coils, by suitable conductors 2 and 2 respectively, and the other sides of these two secondaries are connected by conductors 3 ands? to a common ground connection 5, which may be suitably connected to the engine frame andt-hus be-- ing in electrical connection with the track rails one of which is indicated at 6. The Ruhmkorff coils are indicated at 7- and 8 respectively and between the terminals of the secondaries of .these coils are located the usual spark gaps 9.

Each coil 7 and 8 is provided with a suitable rheotome 10 by means of which a constant current supplied from any suitable source as by a battery 11, is converted into an intermittent or pulsatory current which isv ultimately converted in the secondary of the coil into alternating currents passing the spark gap 9 and thereby generating Hertz-l ian or ether waves to be nally thrown off at the aerial 1, all in the manner common in the practice of wireless telegraphy. It will be.understood that of course the aerial oalfnot e higherabove the engine than is permitted by bridges and tunnels or other low structures along the line of way,but in practice this altitude is found amply suflicient for the propagation of Hertzian Waves for a distance of several miles, which -is ample for the purposes of the system of rail way signaling forming the subject matter of the aforesaid applicatio One side of the battery 11 is connected by conductors'12 and 13 respectively to one side of the primary coil of each of the Ruhmkorfi coils. The other side of the battery 11 is connected by a conductor 14 to one side of a switch 15 which in the drawing is shown of the ordinary plug or Jack type.- The other side of the switch 15 is connected by a conductor 16 to a spring arm 17 mounted onbut insulated from the casing of an electric motor 18 of any suitable type. The'motor 18 is driven by a battery 19 or other suitable source of current connected on one side to one terminal of the -motor by a conductor 20, and on theother side by a conductor 21 to a brush 22 in the path of the movable member 23 of the switch 15. When the switch 15 is closed the circuit is completed from the brush 22 to a conductor 24 leading to the other terminal of the motor 18- and including a first coil is still active.

cession simple switch 25.

The motor drives a cam disk 26 in the path of which is a spring finger 27 adapted to'make contact with the finger 17 to move the same for a distance. In the path of the finger 17 is another spring finger 28 adapted to be ultimately engaged by the finger 17 when the latter is moved by the finger 27 under the action of the cam disk 28.

The spring finger 27 is connectedby a conductor 29 to the other. terminal of the primary Winding of'the coil 8 and the spring finger 28 is connected by a conductor 30 to the other terminal of the primary winding of the coil. 7. I

The motor 18 is under the controLoi a suitable governor 31 by means of which its speed may be fixed and maintained indefinitely.

In the primarycircuit of each coil 7 and 8 there is included a rheostat 32.

in the operation of the system, the motor 18 is assumed to be constantly running and at a regular interval causes a closure of the primary circuit of the coils 7 and 8 in sucthrough the contact fingers 17, 27 and 28, the arrangement being such that one coil has its primary circuit closed before the second coil, and the second coil has its pri-- mary circuit opened before the opening of the first named coil. The result is, that I there issent from the aeriala train ofwaves corresponding to the first named coil, and while this train of waves is being propagated the circuit through the primary Winding of the second coil is established, and another train of vaves is propagated while the The circuit of the second coil is broken prior to ,the breaking of the circuit of the first coil, as the cam disk 26 passes out of active enga ement with the sprin fin er 27. The secon train of waves is .t than the first train of waves, but is active erei ore of shorter duration during waves, being overlapped on each end by the first train of waves.

. On each engine there are two or more receiving elements corresponding in number and adjustment to the number of sending coils in the sending system. Each receiver includes a suitable coherer 33 included in a conductor 34 comin from the aerial '1 and ultimately grounde through the rail 6 and conductor 5. suitable resistance or rheostat 35 for the purpose of adjusting the receiver circuit to the character of the propagated waves.

The local circuit of the coherer 33 may be traced by the conductor 36 to the spring arm 27, through the frame-work of the structures driven by the conductors 37 to a battery 38, and from the battery 38 by a conductor 39 to the relay magnet 40, and back to the other-side of the eoheren. The relay 40 controls another cir- Each conductor 34 includes a the activity of the first train of a motor 18 and then by 1 cuit charged by a battery 41 and this circuit may be traced as follows. From the battery 41 the circuit 'is by the conduetm' 42, dihrough a lamp 43 or other suitable indieating device to one terminal of the relay, thence to a 'bell 44 or other suitable signal preferably an audible signal, thence through an indicator 4.5, through electromagnets 46 and finally returning to the battery 41. In opperative relation to the magnets 45 is an armature 47 arranged to make contact with a circuit terminal 48 in its path as it moves toward the magnet 45. The armature 47 and contact terminal 48 are included in the local circuit of another coherer 4t), and this circuit may be traced from its charging battery 50 through relay magnets 51, then through the coherer and by a conductor 56 to the armature 47, and the circuit is completed from the contact terminal 48 to the battery 50 bythe conductor 52. The relay 51 controls a circuit charged by a battery or other source of current indicated at 53, and this circuit includes a lamp 54 or other suitable visual signal and a bell 55 or other suitable audible signal. The'coherer 49 is included in the aerial circuit by a conductor 56 and with the ground conductor 5 by another conductor 57. The receiving circuit is designed also to include certain train operating devices which however form no part of the presentinvention and are not shown in the drawing. It maybe stated however, that the train controlling devices are designed to operate subsequent to the operation of the visual and audible signals so that if these. last named signals be ignored by the engine man, then the train on entering a danger zone will be automatically brought to a standstill. The receiving apparatus is so dosi ned that the first of a series of train waves If now it be assumed that a train has ena staudstilh the engine man will be aware of the fact that there is danger WllI-lllll a predetermined distance of his train, but will be unaware of the dangerous condition. To enable the engine man or other authorized. person to connnunicatewith the point of danger there is provided a telephone system which forms the subject matter J of the present invention.

In-the drawing there is indicated a tele-.

phone transmitter 57 and a telephone receiver 58, and the ordinary telephone receiver hook is indicated at 59. phone hook 59 controls two circuit terminals (50 and G1. The terminal 60 is connected by a conductor (32 to the conductor let bet-ween the battery 11 and the switch 15. The terminal 61 is connected to one side of the transmitter 57. The other side of the transmitter is connected by a conductor 63 to a terminal tit in the path of a switch 65 carried by the receiver 58 within easy reach of the hand of the operator, and this switch 65 is connected by a conductor 66 to the conductor 5 in oilcuit with the rails ii. The switch 65 is connected to one side of the receiver 58 while the other-side of the receiver coil is con nected by a conductor 67 to the-condifctor 30 before described, and this same side of the receiver is connected by a conductor 68 to a conductor (35) leading from and connected to the conductor 2 before described. Leads ing from the conductrr GS) is a. conductor It) which may be a flexible conductor, say for instance. about 200 ft. in length and at the end of this conductor there is a ground stake 71, adapted to be driven into the ground at a considerable distance from the track 6. When the coils 7 and 8 are used with rheotoines 10 then it is necessary in order to re duce the spark to introduce in the primary circuit in multiple therewith a suitable condenser such as indicated at 72, it being understood that each coil has its individual condenserl One of the coils 7 or 8, say the coil 7 utilized as an inductorium for the telephone circuit and when the telephone is in. use it is advisable to cut out the condenser 72, but when'the coil is in use and the telephone is not being used, then the condenser 72 should remain in the circuit. For this --reason the condenser circuit terminates at two'terminal contacts 7 3, in the path of and adapted to be bridged by the telephone'hook 59 when the telephone receiver is hung therefrom. Then the receiver is lifted from the -hook, then the circuit of the condenser is broken at these terminal contacts 73.

Let it be assumed that the train has come to a standstill because of the presence of some danger either ahead or behind the train,

and such dangerous condition maybe the presence of another train in the same block The tele-- within dangerous proximity, or an open switch, or an open draw in a bridge, or a broken down bridge, or in fact any dangerous condition. Under these conditions it is not necessary that the motor 18 should c011- tinue to cause the sending out of trains of waves. The switch 25 may therefore be opened and the motor be brought to a standstill. The engine man may now cause the closure of the primary circuit of the coil 7 by moving the spring finger 28 against the spring'finger 17. This operationis facili tated by providing the spring finger .28 with a suitable manipulating button 73. By press ingdown upon the button 73 to bring the finger 28 into contact with the finger 17 and the latter ultimately in contact with the finger 27, trains of waves may be propagated in accordance with some recognized code signal system, and the receiving devices within range of sending stations will thereby be notified that at some distant point an operator wishes to talk over the telephone vstci11. Then at eachend the receiver 58 is lifted. from the hook 5%), thus cutting out.

.the condenser 72 of a respective coal 7 orS and cutting in the transmitter 57. 'In the meantime the engine man on the stalled train has inserted the stake 71. at an appropriate distance from the track (3 and after receiving the appropriate signal the operator at the other end will do likewise.

Now "at the tr: i ismitting end the operator closes the switch. (35 thus completing the transmitting circuit, which may be traced from the battery 11 through the conductor (12 to the terminal (30, sent by way otthc book 55) to the terminal (31, and to the transmitter element 57, thence by the conductor 3 and switch (35 to the receiver, and through the latter by the conductor (37 to the conductor 30, and primary coil of the Ruhlnkorli' coil 7, returningby way of the conductor '13 to the other side' of; the battery 11. Now by talking into the transmitter 57 electrical impulses are generated in the primary cirruit thus traced, and those are converted into high tension electrical impulses in the secondary coil of the Ruhmkorfi' coil 7. The terminals of the secondary winding of this coil are connected on one side by the conductor 3, to the conductor 5 and ultimately to the rail 6, and on the other side by the conductor 2 and conductor (39 to the con ductor and stake 71, which latter is inserted in the ground at a'considerable distance from the, rails 6, say one or' two hundred feet." During transmission the receiving end of the line is established through the receiver 58 at that end of the line by having the switch (35 open, when the recei\-'er is included in a circuit. from the rails (3 through the conductor 5 and conductor (37 to one. side of the receiver, and from the other side of the receiver through the conductor (38 to the conductor 70 and stake 71. When it is desired to reply over the same circuit, the receiving circuit is made a transmitting circult by closing thesw'itch 65 and the transmrttlngclrcuit is made a receiving circuit by opening the switch 65 at the correspond has demonstrated that'conversation may be carried on in this manner over a distance of two or more miles, which distance is ample for the stoppageof even high speed trains before coming into close proximity to a dangerous condition.

The Ruhmkorfi coil 7 or 8 as the case may be, operates after the manner of an'ordinary telephone coil, when connected up as described with the. transmitter of the engine carried telephone set, but because of the large size of the coil, and the conditions under which it is operated, it acts with much greater vigor than the ordinary telephone coil. i

The invention'has been described as being used in connection with a wireless propagating system in which Ruhmkorii'coils supplied with ployed. Eyperience has taught, however, that rheotonies are troublesome adjuncts in systems of this character. i ret'erable that the prime source of current for the Buhmkorfi' coils 7 and 8 should be an alternating current generator, in which case the rheotomes become unnecessary and the condensers are omitted. But the battery ll is'still retained for the primary circuit of the transmitter element. All the other circuits remain as described. I

This application a division of the aforesaitl application tiled November 19, 1907, Serial Number 402,856.

What is claimed is:

1. In a systm of the character described, for transmitting trains of waves, said means including an induction coil, and a telephone circuit having a transmitter capable of inclusion in the primary winding of the induction'coil, and a receiver connected to the ground wire of the aerial transmitting system, and provided with a supplemental" ground connection capable of being grounded at .a distance from the aerial ground. k

2. In a system of the character described, means for propagating trains of-waves including an induction coil, ,means for receivmg trains of waves and including signals actuated by the effect of said waves, and a telephone transmitting and receiving system including the said induction coil, and means for grounding two sides of the same at two points spaced apart.

3. In a system of the character described, a means for propagating trains of waves,

the ordinary rheotomes are emiv r an h ving a It is therefore said means including a Ruhmkorfi coil, receivefs responsive to the trains of waves and including signal devices responsive to the 510- a telephone tion of said trains of waves, transmitter inc-ludable in the primary winding of the Ruhmkorii coil, a ground connection for the aerial side of the Ruhmkorflt' coil capable of being placed at a distance from the normal ground connection of the coil, and a receiver bridged across said ground connection.

described,

4. Ina system of the character a means for propagating trains of waves, said means including a Ruhmkorfi coil, receivers responsive to'the trains of waves, and including signal devices responsive to the action of said trains of waves, a telephone transmitter, means for including the transmitter in the primary winding of the Ruhmkorfi' coil at will, a ground connection for the aerial side of the Ruhmkorfi coil capable of being placed at a distance from the normal ground connection of the coil, and a receiver bridged across the said ground connections.

5. In a railway telephone system, a telephone set including a transmitter and reground connection to the track rails, and another ground connection capable of being placed a distance from the track but still in the vicinity of the telephone set.

6. In a telephone system, portable tele phone stations: each including a transmitting element and a receiving element, a con stant ground connection for one side of the receiver and a removable ground connection for the other side of the receiver constantly connected with said receiver and capable of being placed at a distance from the first named ground connection.

in a railway telephone system, a telephone set carried by a train, a ground connection for one side .oi the receiver of the system through the traffic rails of the railway, a'nd a removable ground connection for the other side of the receiver also carried by the'train carrying the telephone set and capable'ot being inserted in the ground at a -distance from the traliic rails.

8. In a railway telephone system, a receiver element grounded on one side through the traffic rails, and means for grounding the other side of the receiver comprising a suitable conductor and a terminal stake carried therebyand insertiblein the ground at a distance from the traific rails.

removable In testimony that I claim the foregoing as my own, I-have hereto aiiixed my signature in the presence or" two witnesses.

EDWARD ROBERT BRODTON.

. Witnesses:

E. H. RoBnn'rsoN, D: P. Bns'rsn, Jr.

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