US1125487A - Combined railway electric traction, telegraph, and signal system. - Google Patents

Description

I v. T. DAY. COMBINED RAILWAY ELECTRIC TRAGTION, TELEGRAPH, AND SIGNAL SYSTEM.

APPLICATION FILED SEPT. 15, 1906.

Patented Jan. 19, 1915.

2 SHEETS-SHEET 1.

. Jkuerztor ll z'nessea." @mx lww W. cm W A. V. T. DAY. OOMBINEDRAILWAY ELECTRIC TRACTION, TELEGRAPH, AND SIGNAL SYSTEM.

APPLICATION FILED SEPT. 15, 1906.

N M ENA MN Dzventor:

Witnesses: @MJ

ALBERT v. r. DAY, or new YORK, n. "r,

HALL swr'rcrr & SIGNAL ooiuraNY, or NEVJ roan, n. 2., A conrona'rron MAINE.

rants ASSIGNOR, BY MESNE ASSIGNMENTS, TO OF COMBINED RAILWAY ELECTRIC TRACTION, TELEGRAPH, AND SIGNAL SYSTEM.

Specification of Letters Patent.

Patented Jan. 319, 1915.

Application filed September 15, 1906. Serial No. 334,733.

. means for railways, employing rail circuits an? periodic current for controlling the signa s.

My object is to provide signaling means peculiarly advantageous in its adaptation to railways in which the track rails are also employed as conductors for periodic traction current, or periodic telegraph current, or both, and I have illustrated such an adaptation of my invention in two sheets marked Left part of Fig. 1- and Right part of Fig.1, which are to be read together as one drawing.

In this instance one of the track rails or L traflic rails R is continuous and the other traflic rail S is divided into signal blocks or sections by means of suitable insulations in this instance, located substantially at the signaling stations E and J respectively. The current for railway motive power or traction and for the telegraph system, and also electric current for operating all the block signaling apparatus of the system, are supplied from a power station which I have marked P and which, in the illustrated instance, is located at the terminus of the railway track. The system includes a thirdrail T adjacent to the railway track and divided into sections by suitable insulations interposed, in the present instance, at the telegraph stations M and Q. The sections into which the third-rail T is thus divided are much longer than the sections into which the signal rail S is divided by its insulations at the signaling stations. These blocks or sections of the third-rail T will be hereinafter designated as third-rail blocks or sections, or telegraph blocks or sections, in contradistinction to the shorter blocks or sections of the signal rail S.

Each insulation in the signal rail S is spanned by an impedance coil such as 3, 3

'3, etc., at the various signaling stations, and

the insulations in the third-rail T are similarly spanned by impedance coils 30" and 30? located substantially at the tele raph stations M and Q; and thereby the signal rail S and the third-rail T are rendered conductively continuous for unidirectional or non-periodic current although the impedance coils effectually isolate the successive rail sections from each other as regards inter-transmission of current components characterized by periodic variation.

The continuous track rail R, and the block signal rail S which is also conductively continuous for unidirectional motive power current, are both employed as return conductors for the motive power or traction current. These track rails are cross-com nected by impedance coils such as 2, 2, 2 etc., located midway between successive block signal stations and acting as cross bonds for unidirectional current while at the same time impeding the transmission of periodic current from rail to rail. The unidirectional or direct current traction generator is, of course, grounded on both the track rails R and S, and delivers current to a line feeder extending out along the railway line. The successive sections of the third-rail T are fed by the line feeder p through impedance coils 7f, 32 and 32, the first impedance coil 19 being located substantially at the power station I and the inipedance coils 32 and 32 being located respectively at the telegraph stations M and Q. In addition, the successive sections of the third-rail are fed by each other through the impedance coils 30 30, etc., which unite such third-rail sections for inter change of unidirectional current.

An alternating current generator 3') is located at the power station P, and delivers alternating current to a transmission line including two conductors g and y) extending out along the railway line. block signaling apparatus at the signalaw' stations B, C, D, E, F, G, H, I, and J are all the same, wherefore the block signal apparatus at the signaling stations B and C may be described as representatives of the apparatus at the other stations. The signaling apparatus at each station excepting A includes a transformer comprising primary and secondary coils such as 5 and 4 .respecth-ely, each primary coil being fed from the alternating current transmission line wires p and 1) and each secondary coil being connected with the track rails of the signal block next in the rear. The secondary coil, such as f of each transformer feeds alternating current to the rail circuit of the signaling block next in rear, such rail circuit of the block B (1' being traceable as follows: from one terminal of the secondary coil 4 to the advance end of the section B U of the signal rail S, thence rearward through such section of the signal rail S to the rear end of the block B C and thence through the alternating current relay mag net 7* and the condenser 6, both included in the signal apparatus B, and from the condenser 6" to the continuous track rail R and thence forward through such track rail to the advance end of the block B C and back to the opposite terminal of the secondary coil 4. Current from the secondary coil 4 traverses the foregoing rail circuit when there is no train or railway vehicle present in the block B C, and, excepting leakage current which passes from rail to rail through the ground and ties, substantially all of the alternating current from such secondary transformer coil 4 traverses such rail circuit, because such alternating current is effectually impeded or refused by the impedance coils 3, 2 and 3 The condenser 6 included in the foregoing rail circuit and its relationship to the alternating current relay 7", constitute an important feature of my invention whereby very important results are attained, as will be described shortly hereinafter.

If a train or railway vehicle were present in the block B G, the alternating current from the secondary coil 4: of the transformer would be short-circuited by the wheels and axles of the train or vehicle and pass freely from one track rail to the other, thus being shunted around the relay 7" so as to effectually prevent the relay from being energized. Under these conditions the contact linger 8 of the relay'is held by any suitable rctractiveforce outof engagement with its cooperating contact stop 9*, so as to maintain the signal semaphore 10 in its danger position indicating that the block B C is occupied. But when there is no train present in the block B C the rear track relay 7 of such block is energized by alternating current flowing through the circuit already traced, so as to maintain its contact finger 8 in contact with the cooperating stop 9 and thus maintain a flow of current through the semaphore-actuating-orretaining electric-mechanism included in series with the contacts 8*, 9 in a local branch circuit bridged across the alternating current line conductors 7), 2 Thus the signaling apparatus at the signal station B always indicates the condition of the block B C, the semaphore 10 of such signaling apparatus being known as a home signal.

To those schooled in the art it will be apparent how the signaling apparatus at any one or more of my signaling stations can be supplemented by an additional semaphore controllable by the condition of the signal block second in advance thereof, such an ad ditional signal semaphore being known as a distant signal. Such distant signals and the additional circuits or apparatus necessary to control them have been omitted from my drawings simply for the sake of greater clearance in the illustration of-the more important rudiments of my invention.

The capacity of the condenser 67 and the inductance of the alternating current relay 7 7 are relatively adjusted for resonancewith the alternating or periodic current employed in the block-signaling rail circuit. This adjustment discharges a most unique and valuable function which can most aptly be explained by a comparison with the old style unidirectional-current or battery-current block signaling systems well known in the prior art. In these battery systems it has been customary to connect a battery with the track rails at the advance end of the signaling block and to connect what is known as the rear track relay with the rails of the same signaling block at the rear end of the block. When no train is present in the signaling block the battery current flows from the advance end of the block through the rails and through the rear track relay so as to clear the signal controlled by such relay at the rear'end of the block. Obviously, in such prior systems, the signaling current encounters only the ohmic resistance of the relay at the rear end of the rail circuit, but even so, it has been found that when the signaling block is very long or when the ground and rail ties are very wet, leakage from rail to rail through the ground and ties is so great as to effectually shunt current from the rear track relay so that it will not clear the signal when the block is clear, unless a battery of consider-- able strength is employed. Now, .when we apply an alternating current to the rails at the advance end of the signalingblock, in lieu of a unidirectionalcurrent, the forego-' ing difficulty is greatly augmented because added to the ohmic resistance of the relay we have its inductive resistance, so called, or its ceunter E. M. F. of selfrmduction, so

- mamas? ductive branch. The conditions make it GX-V ceedingly diflicult to operate a rear track relay through a trafiic-rail circuit with an alternating current when the signaling block is long or when it is subjected to wet weather, unless. an exceedingly strong current is delivered to the rail circuit to make good the excessive leakage. But my provision of capacity adjusted relative to the track relay in resonance with the block signaling current attains that same relationship of impedances through the track relay and through the leakage branch from rail to rail, which relationship is attained in the old battery block signal circuits; and by means of my invention therefore it is possible to clear a block signal through a trafiicrail circuit positively and reliably and without employing an excessive signal-clearing current at the advance end of the rail circuit to make up for the enormous leakage from rail to rail.

Another important function and result of the adjustment of my condenser and track relay in resonance with the block signaling current, is the saving in the expense of the block-bonding impedance coils such as 3, 3", etc., employed to connect the adjacent sections of the block signaling rail S, and a, saving in the resistance losses in the return circuit of the motive power current, and also a saving in the expense of the cross-bonding impedance coils such as 2 2, etc. The resonant adjustment of the rear track relay and its condenser, by reducing the impedance through the relay branch to the ohmic resistance of such branch, makes it possible to operate the track relay with a much lower voltage of block signaling current than the voltage which would be required in the absence of such resonant adjustment. By thus reducing the block-signaling difference of potential between opposite rails required to operate the block signal, my resonant adjustment of relay and condenser makes it possible to employ block-bonding and crossbonding impedance coils of much lower 1mpedance and hence much less expensive in cost of construction and also less wasteful of motive power energy in -the return path of the motive power current. Since these block-bonding and cross-bonding impedance coils are employed to prevent passage of block signaling current between ad acent sections of thesig'nal rail S and between such signal rail and the continuous rail it, it is obvious that the more the voltage or the block signaling current is reduced, the

more we may reduce the size and expense of the impedance coils without impairing their foregoing functions.

Another important function and result of the adjustment of my condenser and tracl: relay in resonance with the block signaling current, is the selective responsiveness oi? such relay to the alternating or periodic current of that particular frequency employed for clearing its particular block signals, and in discrimination against all other alternating or periodic currents such as the alternating or periodic currents employed in my telegraph system, or periodic currents which might be employed in the traction system in lieu of the unidirectional current eniploycd in that embodiment of my invention which- I have specifically illustrated. in the event of an accidental break in one of the track rails, which act as conductors for the telegraph current and the traction current as well as for the block signal current,

or in the event of some other derangement distinctly difi'erent from the periodicities or frequencies of all other periodic currents employed in my system. Should a current higher in frequency than such distinct block signaling current attempt to pass through the relay '4', it would be strongly impeded by the counter E. M. F. of the relay which, at such higher frequency, would be only partly neutralized by the counter E. M. l

of the condenser; and should the relay be subjected to a current lower in frequency than the distinct block signaling current to which it resonantly responds, such current of lower frequency would be effectually opposed by the counter E. M. F. of the con denser which, at such lower frequency, would be only partially neutralized by the inductance of the relay. Thus the relay branch from rail to rail refuses to conduct in substantial degree any current other than the particular block signaling current to which the relay responds in resonance.

In addition to the fixed telegraphic stations M and Q of the telegraph system, 1 11a) illustrated three moving telegraph stations Y, J N, those moving telegraph stutions of the telegraph system being carried on moving trains or railway vehicles. for which reason the three stations will be here inafter or convenience referred to as the trains K, L, N. The trains l and are represented in the telegraph block P M, that is to say, they are represented in that portion or section of the railway track extending from the power station P to the fixed telegraph station M, and through which railway block the first third-rail section extends. The train N is represented in the telegraph block M, Q, extending from the telegraph station'i /i to the telegraph station Q; and comprising the third-rail section M, Q. The wheels and aXles of the trains K, L, and N, are represented respectively at 2", 2, and 2, showing that these trains are located respectively in the signaling blocks A, B, G, D and G, H. The trains take current from the third-rail T through their respective third- rail shoes 5, and 5, such shoes being connected with the conductors 4*, 4', and l, leading to the apparatus on the respective trains, and the apparatus on each train is connected with the axles and wheels of the train by means of conductors such as 3, 3, and 3 on the three trains respectively.

Each train receives motive power or traction current from the third-rail through a circuit which may be traced, for example, on the train K, as follows: from the thirdrail T, through the third-rail shoe 5, conductor 4*, fields 7 of the train motor, armature 6* of the train motor, conductor 3 and wheels and axles 2* to the traflic rails R and Swhich, as already pointed out, constitute a return circuit to the power station. Each train carries also a rotary converter or motor-generator adapted to convert current from the traction generator at the power station P into current suitable for sending telegraphic communications or other signals from the train to a point outside the train, The motorgenerator in this instance comprises a direct current motor armature and two alternating current generator armatures. Considering, for instance, the apparatus of the train K, it will be noted that the traction current passes through the shoe conductor at, thence through the fields 9 of the mtor-generator, motor armature 8 of the motor-generator, and thence to the grounded conductor 3*. The field winding 9 may be employed to excite not only the motor-armature 8 but also the two alternating current generator armatures 10 and 14 These generator armatures 10 and 148 are connected in respective parallel branch circuits leading from the shoe conductor 11 to the grounded conductor 3*, through respective signal keys 13 and 17 and their stationary contact members 12 and 1G and 80" the condensers 11 and and the armatures 10 and lat connected in series with such condensers respectively and with their signal'keys. Each train carries also two receiving instruments such as the receiving sounders 18 and 24* of the train K, connectmanner edin parallel branch circuits between the shoe-conductor 4 and the grounded conduetor 3 These parallel sounder branches include condensers 19 and in series with the Sounders 18 and 24: respectively, and

include also respective controlling switches sounder magnets by sufiicient magnetization thereof.

The fixed stations M and Q of the telegraph system comprises apparatus corre sponding substantially to that carried by the moving trains, excepting the traction motors, third-rail shoes and the wheels and axles of the trains, which are, of course, omitted at the fixed stations. At such fixed stations M and Q, the grounded conductors 3" and 3 are connected directly vwith the continuous track rail R, and the conductors 4 and 4:, corresponding to the shoe conductors of the trains, are connected directly Withrespective telegraph sections of the third-rail T.

Not all the foregoing apparatus of the telegraph system is essential tov the rudimental operation of my invention, nor is it essential that the apparatus shall be embodied" in the specific forms illustrated and described, since any equivalent may be substituted for the sounder or for the condenser or for any other element. For instance, to exemplify one operation of my invention, it may be assumed that all the apparatus on the train K is dispensed with excepting the sounder 24 its condenser 25*, its soundercontrolling switch-26, the conductor 4 leading to thethird'rail shoe, the grounded conductor 3 leading to the wheels and axles, and the traction motor 6*; Now the traction motor 6* will receive motive power current passing in the usual way from the third-rail through such motor and to the traiiic rails included in. the return path of the current;

but the traction current, which in this instance is a unidirectional current, will not pass through the sounder 249 because its condenser 25 will not transmit such traction current. The condenser 25 will, however, transmit a periodic or alternating telegraphic or signaling current to and through the sounder 24; whereby the train K may receive signals or telegraphic intelligence from another station, for instance, from the fixed station M of the telegraph system, through a circuit traceable as follows: From one brush or terminal of the alternating current generator armature 14 of the motorgenerator at the station M, through the condenserv 15", contact stop 16*, signaling meets? or telegraphic key 17, conductor 4" leading to the third-rail section P M, thence through such third rail section to the shoe 5 carried by the train K, and thence through. the shoe conductor at on such train, the sounder-controlling switch 26 condenser 25*, sounder an, grounded conductor 3 wheels and axles 2 and continuous track rail R to the grounded conductor 3* at the station M and through such grounded conductor 3' back, to the opposite brush or terminal of the alternating current generator armature 14 The alternating current thus delivered by the generator armature 14, through the foregoing circuit and its receiving sounder 24 may be of such high frequency that the sounder armature 27* will not be recovered by its retractile spring :29, between successive current pulsations, but will be held down against its stop 28 so long as the sending key 17 is pressed against its contact stop 16".

Obviously, by the foregoingor equivalent means, telegraphic intelligence or other sig-' nals may be transmitted to the train K through its sounder 24 or through any signal receiving device equivalent thereto in the broad aspect of my invention. And such signals may be transmitted in the foregoing instance, regardless of the relationship of inductance and capacity in the sounder and its condenser 25, providing only that the E. M. F. of the telegraphic current is high enough to force through the condenser and the sounder a suificient current to eii'ectually magnetize such sounder and attract its armature. Therefore, my bread invention is in no wise limited to a resonant adjustment or to any other adjustment of inductance and capacity in the sounder or equivalent device and its condenser, although a resonant adjustment of such inductance and capacity is highly advantageous in various ways. For instance, if an alternating traction current be employed in lieu of a unidirectional traction current, the sounder and its condenser may be adjusted'in resonance with a particular signaling current of the telegraph system so that the sounder will respond readily to such particular current while its armature and retractile spring will be adjusted to avoid any response to the alternating current of the traction system which will flow with comparatively weak intensity against the unbalanced counter cl'cctromotive forces of inductance and capacity which are not adjusted in resonance with such traction current. Also when two sounders are provided, such as the sounders 24 and 18" on the train K, in order to receive simultaneously two messages or signals from one or more points outside the moving train, each sounder and its respective condenser may be adjusted relatively to each other resonanw with one of two alternating or periodic currents of ditlerent frequencies. In this instance a given sounder will-resonantly respond to its own particular peri odic or alternating current while itsarma' ture will be adjusted to avoid response to the periodic current which resonantly operates the other sounder and which will flow in comparatively weak degree through the given sounder. Thus, distinct simultaneous messages or signals may be received on one of the moving trains or at one of the fixedstations oi? the telegraph system. The simultaneous messages thus received at one station of the telegraph system may emanate from two other stations of the system or may both emanate from one other station of the system, and in order that two messages may be simultaneously sent from one station I have provided each station of the telegraph system with means for generating and controlling two periodic currents of different frequencies adapted for transmission of intelligence to one or more difierent stations of the system, such means being embodied, in the present instance, in the motor-generators each having two generator armatures controlled by respective sending keys.

As an advantageous arrangement of apparatus it is suggested that all the Sounders uppermost in the diagram of the telegraph system, to wit,.the sounders 24 24:, 24*, 24 and 24: may be adjusted with their respective condensers in resonant responsiveness to periodic current of one particular frequency which may he commonly produced by allof the alternating current generator armatures which are uppermost in the diagram, to wit, the armatures 14 14, 14 14 and li while all the Sounders-lowermost in the diagram may similarly respond to a common erator armatures which are lowermost the diagram.

When the operator at one station is send ing with one of his sending keys, the

sounder at his own station which is respom sive to such sending key may be cutout of circuit to economize the sending current. For instance, if the operator at M is sending a message with his sending key 17", he may open his sounder controlling switch 26 so as to cut out his sounder 2 and avoid waste of the sending current controlled hy the key 17 which sending current will then proceed along the third-rail section P M and alongthe continuous track rail to those sounders resonantly. responsive to such current on one or hoth of the trains K and L, it is desired to send this message simultaneously to tooth trains K and L, the operators on both such trains 26" and 526 closed so as to maintain in circuit their respective sounders 249 and 24, both resonantly responsive to such current. But if it is desired to send such message to the train K only, then the operator-on the train L will open his sounder-controlling switch 26. Now, it is quite apparent that while the foregoing message is being sent by the key 17 at the fixed station 1V, another message may be sent from such fixed station by the key 13, and will operate one or both of the sounders 18 and 18 on the trains K and L, accordingly as one or both of these sounders are included in circuit through their respective sounder controlling switches'20 and 20. Or, while the first mentioned message is' being sent through the sending key 17" at thestation M, the sending key 13 at such' station may be left open and such station may receive a simultaneous message from either of the trains K or L, for instance, from the train K whose operator will send out the message through his sending key 13*, thus delivering to the third-rail section 3 M and to the continuous track rail Pl, a periodic current which will efi'ect resonant response of the sounder 18 at the fixed station M, and which, incidentally, will also efiect resonant response of the sounder 1 -8 on the train L, if the operator of such train has closed his sounder controlling switch 20 to receive such message from the sending key 13 on the train Such examples of the use of my system might be largely multiplied but it is surficient to state that a given sending key can be employed to deliver messages simultaneously to one or all of the stations of the telegraph system which are included in one third-rail section or telegraph section" in common with such given sending key; and that any other sending key included in the same telegraph block or section and control ling a periodic current of di fierent frequency may be similarly employed at the same time. However, if it were desired to send separate messages to a large number of trains all operating on one third-rail section, a large number of different periodic currents would have to be employed, and to avoid this necessity is one object which I have in View in dividing the third-rail into separate telegraph blocks or sections, each telegraph block being restricted to such length of railway track as will be ordinarily occupied by a comparatively small number of separate railway trains or vehicles. Since the third-rail sections are substantially isolated as regards interchange of the periodic telegraph currents, such currents of the same frequency maybe employed without interference in adjacent third-rail sections or blocks, the telegraph current applied to one third-rail section hememe-r ing not elfectually transmitted to the adjacent third-rail sections. at thestation Q; may employ his sending key 17 to transmit intelligence through the medium of the sounder 24: on the train N. without affecting the sounders 24*, 24:, and 24", responsive to telegraph current of the same frequency but located in a difl erent third-rail section. It will be noted that the condensers such as 11 and 15 in series with the generator armatures of the motor generators of the telegraph system, prevent unidirectional motive power current from passing through such generator armatures.

If desired each telegraph block or section of my system may include a fixed station attended by an operator in constant communication with the train despatcher through the medium of the ordinary traindespatching telegraph system, and thereby the train despatcher will be in constant communicationwith every train on his di vision. A train may be recalled after it has passed a railway station or after passing a railway station the train may receive orders to stop and take an. isolated siding to permit another train to pass. Wrecks and stoppages of the trains may be immediately reported from isolated points, and in short many great advantages can be realized from the use of my invention.

It will be apparent that an overhead trolley wire may be employed in lieu of a thirdrail. Since alternating currentis a well known substitute for unidirectional traction current, it may be noted that if the traction generator p is to deliver an alternating current it will be well to omit the impedance coils p 30 32 30, 3%, etc, and feed the third-rail or trolley wire direct from the traction generator without any interposition of impedance coils which would more or less impair the transmission of the alternating'tra-ction current. lln this event the third-rail or trolley wire will constitute a single continuous telegraph conductor such for'instance as exemplified in the third-rail section P M with the impedance coil p omitted. All mowing and fixed stations of the telegraph system will then commonly operate upon such single continuous motional telegraph conductor, it being only necessary to employ telegraph current differi'ng in frequency from the alternating traction current and efiecting resonant or selective response of the telegraph Sounders or receiving instruments. Indeed, as to the broad aspect of my invention, it is sufi'icient that the traction current and the telegraph current or currents be different in character and, although I have particularly described the employment of unidirectional traction current and alternating telegraph current, I do not wish to be limited to this particular choice or arrangement of currents since it is Thus the operator perfectly obvious that the arrangement may be reversed or otherwise modified.

What I claim and desire to secure by Letters Patent is j l. A railway signaling system comprising a signaling apparatus and a signaling circuit in control of the signaling apparatus and including the traffic rails of the railway track and a source of signalin current characterized by a periodic variatlon of distinctive frequency and including inductance and capacity adjusted substantially in resonance with the periodic variation of the signaling current.

2. A railway electric signaling system comprising a section of railway track, a source of, periodic signaling current connected with the rails of the section, a selfinductive electro-translative device and consource of periodic signaling current arranged to deliver such current to the rails of the section, a self-inductive electro-translative device and condenser connected together and relatively adjusted substantially in resonance with the frequency of the periodic signaling current and arranged to receive electrical energy of such frequency from the rails of the section, and a signaling apparatus controllable by the electrostranslative device.

4. A railway electric signaling system comprising a section of a railway track, a source of periodic signaling current arranged to deliver such current to the rails of the section, a self-inductive electro-translative device and a condenser connected in series across the rails of the section and relatively adjusted substantially in resonance with the frequency-of the periodic signaling current, and signaling apparatus controllable by the electro-translative device.

In testimony whereof I have affixed my signature in presence of two witnesses.

- ALBERT V. T. DAY.' Witnesses:

HENRY D. WILLIAMS, BERNARD Gown.

Images