US1249902A

US1249902A - Railway signaling system and apparatus.

Info

Publication number: US1249902A
Application number: US38336607A
Authority: US
Inventors: Clyde J Coleman
Original assignee: Hall Switch & Signal Co
Current assignee: Hall Switch & Signal Co
Priority date: 1907-07-12
Filing date: 1907-07-12
Publication date: 1917-12-11
Anticipated expiration: 1934-12-11

Description

0.1. COLEMAN. RAILWAY SIGNALING SYSTEM AND-APPARATUS APPLICATION FILED IULYIZLWGT- V m Patentefl 10%., H, 191 f.

2 SHEETS-SHEET I.

RAILWAY SIGNALING SYSTEM AND APPARATUS.

APPLICATION FILED IULY 12.1901 I Patented Dec. 11, 1917.

2 SHEETS-SHEET 2.

til

iuivr MAINE.

s ATEN'T on turns 3'. connivrnn, or new YORK, nun, nssienon. BY nnsnn ASSIGNMENTS, T0 'ri-in;

nan-r swrroir & sIeuvnL COMPANY, or NEW Yonn, N. Y.,

not,

A CORPORATION OF RAIL'WAY SIGNALING AND APPARATUS.

Application filed J'uly 12, 1907.

To all whom it may concern:

Be it known that l, CLYDE J. COLEMAN, a citizen of the United States, and a resident of New York city, county of New York, Eitate of New York, have invented certain new and useful Improvements in Railway tiignaling Systems and Apparatus, of which the following is a specification.

My inventionrelates to an electric signaling system for railroads and involves a novel signaling system especially adaptable for use with railroads employing electric traction,

While also including various specific features conducing to the more etiicient and satisfactory operation of such systems.

it have shown my invention and have especially designed the same in connection with a system in which movable arms or semaphores are automatically operated to advise the engineer as to the condition of the track in the block or blocks that he is api as to automatically give warning to an operator or control the operation of the cars.

lln all. the best slgnallng systems thus far developed the signals have been 111 some way controlled by the passage of current in the track, such current being shunted by the wheels and axles of the car or train and being thus diverted from theelectro-responsive devices that control the operation ot' the signals, thesignals being thereby set to danger. My invention involves a signaling tem in which this general method is followed. Where the railroads are operated by steam it has been the custom to out the track into definite sections usually corresponding to the bloclrs of the signal system by inserting insulators between the rails at the end of each block. In this way the traclc is divided into a number of lengths, each supplied with currentand each formingits own a local circuit, l/vl emlaowever, electric trac- Specification of Letters Patent.

blocks through the track rails.

atented Dec. 11, 1917.

Serial No. ceases.

tion is employed it is desirable to employ the rails to carry the traction sideoif the circuit and to do this it is necessary that there shall be a continuous circuit for the traction current for a number of Various means for permitting the free passage of the traction current, while providing means for properly operating the signals by means of a signaling current in the track rails, have Clll'l'GIlt IEO]: 0116 been proposed but such systems have had important disadvantages either in the matter of cost of installation and opera tion or;

as regards reliability and eliiciency or in failing toafi'ord a whollyunobstructed conducting track circuit ZEOlllllG traction cur-;

rent, or in several of these respectscombined;

One feature of my present invention in volves a means for properly confining the signal current to a given portion of the track while at the same time giving a low resist-,

ance track circuit through continuous rails for the traction current. The lneansthat I have provided comprise cross bonds which connect the two rails of thetrack at intervalsand have such a low resistance or impedance asto practically confine the current from any given source to the length: oi track from the said source to the nearest bonds. It is immaterial to my invention in its broader phase what character oi source is employed or how it is arranged or connected with reference to the rails to supply current thereto. These bonds are preferably straight, conductors of low resistance secured 1nte grally to, or otherwise in. good contact with,

the two rails. These bonds are not only ad vantageous in confining each track signaling circuit, while permitting continuous rails to be employed forthe traction current, but they are also advantageous in that they reduce the resistance oi? the track to the passage of the elcctriotraction current by permitting trans for of current when for any reason the sun rent has not equally divided between the rails. At the same time the provision of such bonds, with the source properly ar ranged and designed with reierenceto them, makes it unnecessary to introduce any insulators in the rails or provide any expensive impedance bonds or similar devices. More over, by limiting the circuit of each signal controlling current by means of these negligible impedance bonds I am enabled to make a sharp line of demarcation between adjacent blocks so that, although using continuous rails, there will be no appreciable overlap and, therefore, on the one hand, there is no danger of the signal going to danger at times in the face of the engineer or, on the other hand, of the signal remaining at safety when the train has passed a substantial distance beyond the signal. In accordance with my invention the source of current which supplies the rails may supply them at any point between two succeeding bonds, While an electro-responsive device is arranged between the source and. a bond so that it will receive current when there is no train between a given source and a given bond and the track is intact, while the current Will be diverted from them when there is a train between such points.

Another feature of my invention involves the controlling of such electro-responsive devices by coils arranged in inductive relation to the track itself and this feature I prefer to use in connection with the employment of the bonds of negligible impedance This feature of my invention involves the placing of a coil in inductive relation with one, orpreferably, both. rails of the track and at a distance from the point at which current is supplied tothe track. This coil then acts as a secondary of a transformer, the rails themselves being the primary and the current supplied to said coil actuates a suitable relay controlling the local circuit of the signals. lVhenever the train is adjacent to the point at which the current is supplied to the rails of the track, or whenever it is between said point and the said coil, the current is diverted from the rails so that there is no longer an inducing current in them and substantially no current will be produced in the coil. At such times the local signal circuit is opened and the signals go to danger. Preferably, but not necessarily, I connect the source of current to the track rails at about the center of a block, providing bonds of negligible impedance at the ends of the block and place a coil in inductive relation with the rails close'to the end of the block. The current from this coil supplies a relay controlling the local signal circuit. lVith this arrangement the train must properly control the signal whatever be itsposition in the block because as soon as a pair of wheels have advanced far enough .beyond the bond to have passed to a point where the diversion of the current from the rails will cause the transformer action to cease, the relay that receives current from the coil that is in inductive relation to the track at that point will be d eenergized. There is, therefore, through the rails and the bond a complete circuit from the source and this circuit is complete independently of the circuits of the signaling apparatus. The coil whose current determines the current to the signal controlling relays is in operative relation to the rails of the track where they are adjacent to the bond so as to receive current whose value is determined by the current in such rails. On the other hand, the current in the bond includes also current from the source at the other side of the bond in another block and it is for this reason that the signal controlling relays are arranged to receive a current determined by the current in a rail rather than by that in the bond.

ince the relay receives its current from a coil by its operative relation to this definite short length of track it must necessarily be energized by but a minute portion of the energy supplied to the closed track circuit by the source. This employment of a relay energized by the current in a part of the track circuit having an impedance to the flow of signal controlling current not greater than that of a definite short length of rail is a feature of my invention which enables a practical continuous rail system to be provided having no overlap such as has always been necessary in previously proposed con tinuous rail systems in all of which the impedance of the portion of the track circuit which must be shunted by the train to produce the required dcenergization of the relay has always been so high that it becomes substantially deenergized by a train a relatively long distance before it reaches said portion of the circuit.

Another feature of my invention, which I prefer to employ but which is not essential to the employment of the features of invention already described, comprises the operation of the switches or relays controlling the local circuit by means other than the current supplied from the track rails, while determining the time of the actuation of said relay by the flow of current in the track rails. This feature of invention also involves a novel construction and ar 'angement of relay to attain this mode of operation. This feature of my invention is advantageous since it permits a safe and reliable actuation of the local signal circuit by relatively feeble currents taken from the track rails.

These and other features of my invention will be set forth more fully hereinafter in the course of the detailed description of the specific embodiments I have illustrated. I will now describe these specific embodiments and will thereafter point out my invention in the claims.

Referring to the drawings Figure l illustrates diagrammatically a normal clear signal system embodying the various features of my system, while Fig. 2 is a more simple diagram illustrating the more important Ill) llfl

lll

features of my invention applied to operate home signals only.

ltwill be understoodthat it is immaterial to the employment of my invention whether it is applied to a normal danger or a normal safety system or, indeed, whether the chang ing course'of the current in the track rails, due to the passage of a train over the track, operates visible signals or operates some other character of devices that are to be undersood as being included by me when l. refer to signals and signaling systems.

A, A refer to rails of the railroad track. Each of the drawings shows a length of track corresponding to two full blocks and portions of two other blocks. As indicated, the rails A, A are electrically continuous throughout the portion of track shown and may be continuous for as many blocks as desired. The four blocks are numbered 1, 2, 3, and B, B, B represent swinging semaphore arms placed at substantially the entrance to each block. These arms may be of the ordinary construction of such arms, being arranged to have a gravity danger position except as controlled by electro-responsive devices acting upon them. Each of these arms is to stand at the danger position when there is a train on the track in the block beyond the arm, or when there is any other condition that takes away the current from the electro-responsive devices governing the arm. C, C, C are bonds connecting the rails at intervals. In the present instance, these bonds correspond in number to the signaling arms. This is not an essential to my invention. but it is an arrangement to be preferred. These bonds are of relatively low or negligible impedance. By this I mean that they are of such a character as to afford so small an oppositionto the flow of the signal controlling current that a current supplied to the rails at one side of such a bond will not pass beyond the bond in sufficient quantity to have any practical effect uponthe electro-responsive devices actuated by the changing flow of current in the track beyond the bond. Preferably the bonds are simply straight conducting bars of ample crosssection and intimately connectedwith both rails. lf thesignalcontrolling current supplied to the track rails is an inductive current then to have the neglible impedance necessary the bonds should be of small ohmic resistance and also of small inductance, while if the signal controlling current should be noi'linductive in character it would be i1nmaterial whether such bonds have a high induc'tance or not since a high inductance would have no effect upon impeding the flow of a noninductive current.

D is a prime source of signal controlling current which is in the present case assumed to be an alternating current dynamo.

So far I have only described elements common to the two figures of the drawings accompanying the specification, but in. order to complete the description of an operative system I will continue by first describing the more simple ar angement shown in Fig. 2 of the drawings.

In this figure the circuit of the source D of signal controlling current supplies the primaries E, E of transformers, these primaries being connected in parallel with each other. The secondaries F, F of these transformers are connected at opposite ends to the two rails A, A. The secondary F is connected to the rails at about the center of the block 2, while the secondary F is connected to the rail atabout the center of the block 3, it being understood that these form sources for the signal current in each block and that blocks 1 and etare likewise supplied with currents from similar transformers not shown. Taking the block 2 it will be noted that the current from the secondary F has two circuits, one to the left from one side of the transformer through the rail A, the bond C and the rail A, and the other at the right of the transformer through the rail A, the bond C and the rail A. The bond 0 being of negligible impedance, as above set forth, will cause the difference of potential between the rails at the bond to be substantially zero, and this is equally true at the point at which the bond 0 is provided. l l hatever, therefore, the distance of the va rious sources from the bonds or from each other, and'whatever therelative design and capacities of such sources, the currentfrom each source is confined within that part of the track included between the bonds on opposite sides of the source. The sources are SllOWIl connected directly to the rails but it is not essential whether they supply the current to the rail in this way or through intermediate apparatus or inductively.

From each track source, therefore, there are two circuits, one on each side thereof. Between adjacent sources there is always a well defined point of substantially zero dif ference of potential between the rails, which is fixed by the bond connecting them. When there is no train between sources there are circuits through thetrack, which are com plete independently of the apparatus constituting the signal controlling devices. The current employed for operatingthe latter is obtained by placing an electro'responsive device in operative relation with this track circuit, and, preferably in inductive relation to the rails, at a point near the bond, sothat the current taken by the electro-responsive device will have a value determined by the electrical condition of that part of the track circuit- G, G, G etc, are coils placed in inductive relation to. the rails of the tracl; so as to produce a current when the signal controlling Fr ll;

current is flowing through the rails where adjacent to said coils. I prefer to place these coils at points adjacent to the bonds C, C,

etc., being just far enough away from said 5 bonds so that the bonds will not have a listurbing inductive effect upon the coils. The current from these coils G, G, G is supplied to relays H, H, etc.,which relays control the local signal circuit or the circuit which directly acts upon the electro-magnets governing the movement of the semaphore arms. Thus in Fig. 2 each of these relays indicated as a solenoidal coil which acts to draw down one end of a ever h, the other end of said lever being weighted at It. When there is current in the coil of the relay the arm it is in the position indicated in Fig. 2 for all the relays except H The semaphore arms B, B, B are moved to safety position when the electro-magnets J, J, J are energized. The currents for energizing these coils are received from local sources which, in Fig. 2, are illustrated as batteries K, K, K The relays in any given block control the circuit from the battery to the magnet of that block, said relays being in series in such circuit.

Thus in the block 2 of Fig. 2 no train is supposed to be present. Under these circumstances, the current supplied by the secondary F passes through the rails to the bond C and thus produces a current inductively in the coil G, which current is sup plied to the coil H and maintains the switch controlled by that coil closed. In the same way the coil G is supplying current to the coil H and thereby holding the switch controlled by the latter coil closed. The current may therefore pass freely from the battery K through the electro-magnet J and thus hold the semaphore arm B at the position indicating a clear rack. If either of the switches controlled by the coils H and 1H? wereopened the local signal cir euit supplied by v battery K would be opened and the semaphore arm B would go to danger. v g

It is a very important desideratum in all block signaling systems that the signal should go to danger when there is a break in the track rail. It will be noted that my invention provides for this. Thus referring to block 2 of Fig. 2, which is indicated as clear, it will be seen that in order to supply the current to both the coils H and H it is necessary that there should be at'all points of the block a continuous rail conductor on each side of the track. Any break, therefore, that would render the circuit on either side of the transformer F discontinuous would cause the opening of the local signal circuit and the movement of the semaphore arm B to danger- When a train enters a block the situation is that indicated in block 3 of Fig. 2. L, L

represent two axles of a train connecting the opposite track rails through the wheels. These wheels rest upon the track at points between the transformer F and the bond C. The circuit to the left of the transformer F therefore includes these wheels and axles and that part of the rails to the left of these wheels is no longer supplied with signal controlling current from F. The transformer action between the rails and the coil G therefore ceases and no current is supplied by the coil G to the relay coil H The circuit from the battery K to the magnet J is therefore opened by the switch arm governed by the coil ll and the semaphore arm B" is set at danger. lefore the axles L reach the points to which the secondary l is connected to the rails the secondary will be so nearly short circuited as to reduce the current passing to the right to bond U to such a negligible quantity as to cause the coil G to no longer supply current to the relay ll thus opening the same circuit the switch governed by the relay coil ll". At this moment the circuit of the coil J will be opened at two points. A. further advance of the train to a substantial distance past the secondary 1*" will cause the switch governed by H to close,

but the switch governed by ll will remain opened until the last wheels of the train have substantially reached the bond C at which time the forward wheels of the car or train will have passed the bond C and caused the semaphore arm B to be put to danger.

il' hilel have in the simple diagrammatic illustration of Fig.2 shown the various preferred relations of the dilferent devices constituting the system, yet it will be understood that in order to obtain the benefits of the bonds of negligible impedance and the coils inductively related to the track rails, or either of them, it is not essential that the various elements of the system be arranged and connected precisely as indicated in this drawing.

In the foregoing description of the system as illustrated in Fig. 2 1 have referred to the same without reference to the particular power used for the traction of the vehicle, but I have shown an arrangement which may be used whether the traction be electric or steam or of any other character, and if electric, whether it be direct current or alternating current. It is to be understood that my invention may be employed with an inductive signal controlling current whatever the character of current employed for traction may be, provided tl apparatus is suitably designed and arranged and, so far as the bonds of negligible impedance are concerned, it is immaterial what character of current I employ for the signal controlling current.

lit)

, controlling current D, tha secondaries F, F,

the coils G, Gr, etc, inductively related to the rails, are all the same in Fig. l as in Fig. 2 and perform the same functions.

M is a source of electric power for the traction current, being indicated as a direct current generator, one terminal of which is connected to the conductor 5, which may be, for example, a third rail, while the other is connected to the track rails. Conductor 5, in the present instance, also forms part of till the circuit of the generator D supplying the power for the signal controlling; current. E E E and E are primaries of series transformers, these primaries being placed in the circuit of the source l). The secondaries oi these transformers supply signal controlling current to the track rails, the secondaries F and F being shown as connected directly to the rails as in the case of the transformers F and if, while the second aries F and F are shown as supplying current to the primaries Etand E which are in inductive relation to the secondaries l3 and l3". llt is immaterial whether the series transformers supply the rails directly as in the case of the secondaries F and F or indirectly as in the case oi the secondaries F and T It is also immaterial to my invention whether or not series transformers are employed, the advantage oi the series arrangement being that it limits the flow of current in any one signal controlling circuit when it is short-circuitcd through the train.

'llhe distant signals are represented by the semaphore arms N, N, N which are of the usual type having a gravity danger position and moved to clear position when there current in the coils O, 0', O

In the case of Fig. 1 the coils G, G, etc, supply current to coils H, H H H, H and H so that these coils,like the coils H to H of Fig. 2, are supplied with current when the signal controlling circuit induces a current in the coils G, G- etc, but are not supplied with current when their respective coils G, G are not producing current, bea cause of the passage of a train, or because oi? a broken rail, or because of the failure otthe source or oi a circuit forming part of the signaling system. The coils H to H inclusive, magnetize members P oil magnet,

inable material, which rest at one end upon.

coil lit.-

the power of the motors actual movement of: the switch.

disks P, of magnetizable material. The members P move onbcarings p and have a movement from a position engaging a contact 72 to another position in which the connection between P and is broiren. The former position is that occupied by five of the arms P of Fig. 1, while the latter positioi'i that occupied by the arm in coiiperation with the The disks l? are continuously rotated by small lternating current induction motors Q, which are supplied with current from transformers Q, whose primaries are, in the present instance, in the circuit oi the source D and in series with the primaries E to E. "When there is no current in any ot' the coils Tl. to H, the lower end of the member l? is moved to the right under the influence of the springs Q, as indicated in the case of thefarm l? that is in cooperation with the, coil H When, however, a current is supplied to any of the coils H to H ,as will be the case when the track is clear, the coil magnetizes its maguetizablc member l3 and, therefore, the contacting surfaces 01 the arm l? and the disk P, Be cause ofthe it'rictionthus produced between these contacting surfaces the arm P is clutched and moved by the rotating disk P to the position of engagement between P and 7), thereby closing the local signal circuit.

The coils H to H with the switch me1nbers l the disks l? and the constantly rotating motors Q constitute relays controlled by the coils G to G the currents in the coils of these relays determining the time of actuation of the relay, but not themselves giving the actuating power. The actual actuation of these relays is by means independent of the current in the coils H to H, that is by This enables the relays to be controlled by an extremely feeble current because such current does not need to be powerful enough to eilect the lit is not essential to the employment of my bread invcntion that this particular character of relay should be employed, but it has these features of advantage and may be employed not only in connection with other features of my invention, but in any type of signal system.

in Fig. 1 the train L is shown in block l whereby current is shunted from the track circuit to the rightof the coil G and theretore current is not induced in this coil nor supplied to the coil H. For this reason the relay controlled by the coil H is open, the home and distant signals B and N are set at danger and the distant signal N at the entrance to the previous block is set at danger. 0n the other hand, the signals at the entrance to the blocl: are both at clear. I will now explain how these various results are effected.

r The movement of the arms P of the relays indirectly control the coils J, J, J of the relays R, R, R

v governed in part by the relay arms P and in part by switches S, S, S which are directly moved by the movement of the home signal, being mechanically connected thereto. Each of the switches R, R, R has a swinging switch member 1" having a central gravity position (seeR and a position at each side of this gravity position (see R and R) which the arm 1" takes according to whether the coil 1" is in an active circuit or whether the coil r is in such a circuit. In the gravity position, which is the position occupied by the member 1" of the switch R the coils r and r are connected respectively to a contact r at the left hand end of the switch and to a similar contact 1 at the right hand end of the switch through springs r and 7'. lVhen the switch is tilted so that the left hand end is uppermost, the spring r is connected to one side (which I will hereinafter call the positive side for simplicity of explanation) through the contact r and the conductors connected therewith as indicated. hen the right hand end of the switch arm 1" is up, as shown at switch R, spring 1* is connected to ground through contact i lVhen the track is clear and in good order for the length of two blocks, the rocking switch assumes the position shown by the switch R. It is held in this position because current passes from conductor 5 to the contact r of switch R thence through the coil 0, thence through the conductor governed by the relays having coils H and H thence through the switch S mechanically connected to the home signal B of the next block, and thence to ground. With the switch in this position there is a circuit from the conductor 5 directly through the coil J controlling the home signal 13 and thence through the fixed contact r and contact r to ground. At the same time the coil 0, controlling the distant signal N, is energized, the current passing from conductor 5 through contacts 4, 1 through coil 0, contact r and contact 1* to ground. iVhen there is a train in the block governed by the signals the switch member 9" assumes the gravity position, as indicated by switch R The train L in block 4 has shunted the current that would pass through the rails in that block and the bond C so that the coil G is not supplying current to the coil H The relay arm P governed by the coil H has therefore been moved to the open position by its spring Q and the circuit of the coils r, r of switch R has been opened at that point. As there is current in neither of these coils the memher 1' of the switch R takes the gravity position and, therefore, contacts with neither of the fixed contacts 1, T 9. Under these circumstances the circuit to the coil J controlling the home signal, is broken at the ground side, while the circuit to the coil controlling the distant signal, is broken at both sides. The home and distant signals 13 and N are therefore set at danger, as indicated. The movement of the home signal B moves the switch S thus connecting the conductor 5 through the contacts overncd by coils H H with the coils a" 1", governing the switch member B. This causes a current to pass from conductor 5 through coils 1*, contacts 1 and P to the round side of this circuit, energizing coil r" and tilting the arm not switch R to the position shown. By this movement of the switch the current can pass through the coil J directly controlling the home signal B, a ground connection for said coil being completed. through the contact 9 and contact r of switch R.

It is obvious that various modifications may be made in the constructions and arrangements which I have particularly described within the principle and scope of my invention as severally set out in the following claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. In a block signaling system. a conductively continuous track, bonds of negligible impedance connecting the rails of the track at the ends of a block, means for Slll'JPlYillg current to the rails intermediate the block ends, and electroresponsi\'e devices arranged to affect the operation of the signals and controlled in accordance with the flow of current in said rails.

2. In a railway block signaling system employing the opposite track rails as conductors of opposite polarity in a signal controlling circuit, bonds of negligible impedance connecting the rails of the track at substantially the ends of each block.

3. A means for confining the flow of a signal controlling current within a definite portion of a railway track, comprising bonds of negligible in'ipedance connecting the rails at each end of the track portion in which the current is to be confined.

4. In a railway signaling system, a conductively continuous track, bonds oi ncgligible impedance connecting the rails at intervals, sources of signal controlling current connected to the rails intern'iediate said bonds. and electro-responsive devices arranged to affect the operation of the signals and controlled in accordance with the [low of current in the rails between said sources and said bonds.

5. In a railway signaling system, a conlid masses ductively continuous track, bonds of negligible impedance connecting the rails at in tervals, sources of current arranged to produce a difference of potential between the two rails at points hater-mediate said bonds, and signal controlling electro-responsive devices connected and arranged to be actuated by the current tlowing from said sources to said bonds.

6. In a railway sigi'ialing system, a couductively continuous track, bonds of negligible impedance connecting the rails at intervals, a source of signal controlling current connected to the rails intermediate each adjacent pair or bonds, and. elcctro-rcspoir sire devicesarranged to aftect the operation of the signals and controlled in accordance with the flow of current in the rails between said sources and said bonds.

7, ln a railway signalingsystem, a con ductively continuous track, bonds of ncgligible impedance connecting the rails at intervals, sources of signal controlling current connected to the rails intermediate said bonds, signal controlling devices, and elec tro-responsive lQVlCBS for governing the same connected and arranged to be actuated in one direction or the other according to whether or not the current from the source is diverted from the rails between a source and one of said bonds.

lfn a railway signaling system, a block formed by the rails or the track and low impedance bonds connecting said rails, or source oi. current supply connected. to the rails and having signal controlling circuits through one rail, a bond and thence through the other rail, and electro-responsive si -nal controlling devices energized responsively to the flow of current in said circuits.

9, ln a. railway signaling system, means "For supplying an electric current to the rails of the track. a. coil. in inductive relation to said rails, a signal, and means for actuating said signal responsii'ely to current changes in said coil.

l0. la a railway signaling system, means for supplying an electric current to the rails of the track, a coil arranged with its sides in inductive relation with the opposite rails oi? the track, a signal, and means for actuating said signal .ii'csponsively to current changes in said coil.

11. ln a railway signaling system, a source of electric supply, a circuit supplied thereby including track rails, said circuit being so connected to the source and arranged that the current is in opposite direction in the two rails, a coil in inductive relation with both rails, a, signal, and means tor actuating said signal responsively to current changes in said coil. i

19. lln a railway signaling system, the

' track rails, a source of supply having one of its. poles. connected to. each rail, a bond of each .tra ch rai negligible impedance connecting the rails, a. coil in inductive relation to the rails at point intermediate the source and the bond, a signal, and means tor influencing the same responsively to current changes in said coil.

13, lln a railway signaling system, the track rails, a source (it supply having one oit its poles connected to each rail, a low impedance bond connecting the rails, a coil in electrical cooperation with the rails at a point intermediate the source and the hond, a signal, and means for influencing the same rcsponsively to current changes in said coil.

14-. lln a railway signaling system, the track rails and two bonds of low impedance connecting them, a. sourceof current sup ply intermediate the bonds with one pole connected to each rail, two coils in electrical cooperation with said rails at points between the source and thehonds, asi nal and means for a ctuatiug the same upon a given decrease oit current in either coil.

1.5. in a railway signaling system, the track rails and two bonds ct low impedance connecting them, a source of current supply intermediate the bonds with one pole connected to each rail, two coils inductively re lated to said rails at points between the sour-0*v and the bonds, a sigi'ial, and means for actuating the same upon a given decrease of current in e ther coil.

ll'i. lln av railway track signaling system, conductively continuous track rails, bonds of negligible impedance connnecting the rails at intervals, sources oit current supply connected to the rails liietween each pair of bonds. a coil in electrical cooperation with the rails between] each source and each bond, signals, andmcans tor actuating each of the same upon a given decrease of current in either (it the coils between a given pair of said bonds.

17. l'n a railway track signaling system, conductirely continuous track rails, bonds of negli ilile lll'lPBlluDCO connecting the rails at int. :11, sources ot current supply connected to the rails between each pair of bonds, a coil inductively related to the rails between each source and each bond, signals, and. means for actuating each. of the same upon a, given decrease oi current in either of the coils between a given pair of said bonds.

ltd. In a railway signaling system, the rails oi the tracln a. bond of negligible impedance connoctng them, a source of electric supply delivering current to the rails at a substantial d stance from said bond, and a coil adjacent to the bond and inductively re latcd to said track rails.

19. In a railway signaling system, the a hond ct neglioihle impedance I them, a iourcc ot electric supply tothertraclr rails at a substantial.

connectii connectec distance from the bend, a coil inductively related to the rails adjacent to the bend, a relay controlled by the current in said coil, and a signaling circuit controlled by said relay. 7

20. In a railway signaling system, the track rails, a bond of negligible impedance connecting them, a source of electric supply delivering current to the track rails at a substantial distance from the bond, a coil receiving current responsively to current variations at given points in the rail circuit, a switch, means for determining the actuation of said switch in accordance with the current in said coil and for actuating the switch by means independent of the current in said coil, and a signal circuit controlled by the movement of said switch.

21. In a railway signaling system, the track rails, a bond of negligible impedance connecting them, a source of electric supply connected to the track rails at a substantial distance from the bond, a coil in inductive relation to the rails of the track between the source and the bend, a circuit supplied by said coil, a signal circuit, and a switch controlling the same, means dependent upon the current in the circuit supplied by said coil for determining the actuation of said switch, and means independent of said current for actuating the switch.

22. In a railway signaling system, a source of electric power, a circuit supplied thereby, part of which includes a length of the track rails and a bond of low impedance connecting the same, and an electro-responsive signal controlling device in operative relation with a track rail adjacent to said bond.

23. In a railway signaling system, a source of electric power, a circuit supplied thereby, part of which includes a length of the track rails and a bond of negligible impedance connecting the same, and an electroresponsive signal controlling device energized when there is a flow of current through said bond and length of rails.

24. In a railway signaling system alength of track rails and a conducting bond connecting them, and an electro-responsive signal controlling device in operative relation with a track rail adjacent to said bond.

25. In a, railway signaling system a length of track rails and a bond of negligible impedance connecting them, and an electroresponsive signal controlling device energized by the flow of current through said rails and bond.

26. In a railway signaling system, a block formed by the rails of the track and conducting bonds connecting said rails, a source of current supply connected to the rails and forming circuit each through one rail, a bond and thence through the other rail, and electro-responsive signal controlling devices energized responsively to the flow of current in a given portion of the rail of said circuit.

27. In a railway signaling system, a signal controlling circuit, a coil supplied with current thereby, a switch, means for determining the actuation of said switch in accordance with the current in said coil, independent means for actuating said switch and a signal circuit controlled by the movement of said switch.

28. In a railway signaling system, the combination of the track rails, a source of signal controlling current supply in operative relation therewith, a bond connecting the rails and completing the track circuit, a coil in operative relation with one of said rails adjacent to said bond and between the same and said source, a signal, and means for controlling the same according to the flow of current in said coil.

29. In a railway signaling system, two sources of signal controlling current, a pair of conductively continuous rails supplied thereby at diiierent points, and a bond connecting the rails at a point between said sources and completing the circuits from the respective sources.

30. In a railway signaling system, two sources of signal controlling current, a pair of conductively continuous rails supplied thereby at different points, a bond connecting the rails at a point between said sources and completing the circuits lrom the respective sources, and electro-responsive devices, in operative relation one with each of said circuits.

31. In a railway signaling system, two sources of signal controlling current, a pair of conductively continuous rails supplied thereby at different points, a bond connect ing the rails at a point between said sources and completing the circuits from the respective sources, and electro-responsive devices, one in operative relation to a track rail where adjacent to -said bond and the other in operative relation to a track rail where adjacent to said bond but on the opposite side thereof.

32. The combination in a signaling system for electric railways, of a power circuit for propelling the cars of which the two trailic rails form a part and are continuous, closed track circuits, a source of signaling energy fed to the rails of each track circuit, and a translating device operatively related to the trailic rails for controlling a signal, a cross-bond between the rails, a circuit in inductive relation with the rails and a translating device in the last mentioned circuit.

33. In a railway signaling system, a track having conductively continuous rails, sources of signal controlling current supplying the same at intervals, there being between each pair of adjacent sources a place in the track.

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circuit of normally substantially zero .terence of potential or; the current of said sources from one side to the other, electro responsive devices operative relation to the track circuits at points between each of said zero points and each source, and signals operatively related to said electroresponsive devices. 3%. lln a railway sigl aling system, a track having conductively continuous rails, sources of signal controlling current supplying the same at intervals, there being between each pair of adjacent sources a )lace in the t ack circuit of normally substantially Zero lierence of potential of the current of said sources from one side to, the other, electroresponsive devices in operative relation to the track circuit at points relatively near and at each side of said zero points, and signals operatively related to said clectroresponsive devices.

I a i way igna ng ystem, a t ack having conductively continuous rails, sources ol signal controlling currentsupplyingthe same at intervals, means for producing a normally substantially zero difference of potential for each pair oi. adjacent sources at a place in the track circuit bet veen said sources, and signal controlling electro responsive devices operatively related the track circuit at points between each source and each of said zero places.

36. ln a railway signaling system, track having conductively continuous rails, sources of signal controlling current supplying the same at intervals, means for producing a normally substantially zero dii'l'erence of potential for each pair of adjacent sources at a place between said sources, and signal controlling electro-responsive devices operfv l d t he ra k ircuitat Pai at each side of a points.

3?. ln a railway signaling system, conductively continuous track ra1ls,'a source oi. signal current supply operatively related thereto, and a bond connecting the rails: and forming a definite point of substantially zero difference of potential for the track circuit supplied by said source.

88. ln' a railway signaling system, conductively continuous track rails, a source of signal current supply operatively related thereto, a bond connecting the rails and causing substantial Zero diflerence of potential between the rails at a definite location in the track circuit supplied, an electroresponsive signal controlling device in operative relation to the rail circuit at a point e i e y ne r the bend- 3 an el ctri r way ste sunda tively continuous track rails, a source of u ua ur ent ha g one s de w re to the rails, sources ofsignal controllino cuna la i y sear sa w of sources of signal controlling curl,

the Balls at intervals, means tor producing points of normally acre ditlerence potential at a place between each pair the current from said sources, and elecwrrs rensive devi in Oper t ve el Q with thetia cl: between each source ofsignal controlling current and eaclr saitlzero place.

1L0, In an electric railway systernllconductiyely continuous track rails a source o f ro urre hav n one Si seaweed t the rails, sources or signal controllin curren im if es d fferen e Q1 Po ntial t the rails at ervals, negligible impedance 1 9 1? came as h ra ls ar rs sau e et s'nel' w eelers" was, nd a1 elsetro responsive dense in operative relation ea t tr k t a h le of as elati ely near each bond' i al 1 an el ric ailway sy t m; ai sl 1l 1 a d: was ee-a e p w r cur-r st le i s 1 1 s side eases the rails, sources of signal controlling current supplying a dillerence ol potential to the ra a nter a s, negli ib e iniii daae connecting rails betn 'e'erl sources of signal controlling current, and an elec re siv d vis in P stir i alics are a localized portion of the track at each s de qf and elat s we re ad: 42. In an electric railway systen' conductively continuous tracl: rails,'a source of power current having one side connected to the rails, sources ofsignal controlling curea s pplyi a d us of Pswitial t as r ls at in rv s ne b im anc bl nd onn ct ng e as b twe n atire of signal controlling current, an electroresponsive device in operativerelation ivlth thetrack ateach side brand relatively near each bond, and signals each in operatiye relation with the electro esponsiye (latices between sucessirelaondsQ v .413. In an electric railway systern, condom tively continuous track rails, of povver current having one side connected to the rails, an alternating current source, transformers supplied thereby havin their secondaries co inected across the rails at intervals, means for providing norinally substantially zero ditlerence of potential ustweentlie rails at a point between each pair of successive secondaries, an clectro-respon sive device in operative relation to the track bet veeneach of said zero points and said transformers, and signals in operati e relaliQI to said electro responsive dev ces.

In an electric railway 'systennco nduo tivelycontinnous track rails, source of power current having one side connected to {the rails, an alternating current source, transformers supplied thereby having their secondaries connected acros he rails at in .tervals, nieans for producing nor al-1v sub remain r e erase a ratalts "b rue tween the rails at a point between each pair of successive secondaries, an electro-responsive device in operative relation to the track at each side of and relatively near each of saidzero points, and signals in operative relation to said electro-responsive devices.

. 45. In an electric railway system, conduc- Qtively continuous track rails, a source of power current having one side connected to the rails, an alternating current source, transformers supplied thereby having their secondaries connected across the rails at intervals, a low impedance bond connecting the rails at a point between each pair of successive secondaries, an electro-responsive device in operative relation to the track between each band and transformer, and signals in operative relation to said electrotively continuous track rails, a source of power current having one side connected to the rails, an alternating current source, transformers supplied thereby having their secondaries connected across the rails at intervals, a low impedance bond connecting therails at a point between each pair vof successive secondaries, an electro-responsive device in inductive relation to the track at each side of and relatively near each bond, and signals in operative relation to said electro-responsive devices.

48. In an electric railway system, a source of power current, conductively continuous rails electrically connected by low impediance bonds at intervals and together constituting one side of the power circuit, means for supplylng an alternating current dif- V ference of potential to the rails between successive bonds, electro-responsive devices in operative relation with the track between successive bonds, and signals in operative relation with said electro-responsive devices.

49. In an electric railway system, a source of power current, conductively continuous rails eleetrically connected by low impedance bonds at intervals and together con- ,stituting one side of the power circuit, means for supplying an alternatin current difference of potential to the rai s between suecess ve bonds, electro-responsive devices in operative relation with a definitesection of the track between successive bonds, and sig nals in operative relation with said electroresponsive devices.

50. In an electric railway systen'i, a source of power current, conductively continuous rails electrically connected by low impedance bonds at intervals and together constituting one side of the power circuit, means for supplying an alternating current dilicrcnce of potential to the rails between successive bonds, electro-responsive devices in operative relation with the track each at a point relatively near one of the bonds, and signals in operative relation with said electro-rcspousive devices.

51. In an electric railway system, a source of power current, conductively continuous rails electrically connected by low impedance bonds at inter uils and together constituting one side of the power circuit, means for supplying an alternating current dillerence of potential to the rails between successive bonds, elcctro-responsive devices in operative relation with a definite section of the track each at a point relatively near one oi? the bonds, and signals in operative relation with said electro-responsive devices.

52. In an electric railway system, a source of power current, conductively continuoiev rails electrically connected by low impedance bonds at intervals and together constituting one side of the power circuit, means l'or sup-- plying an alternating current diti'crence oi potential to the rails between sin-cessivc bonds, electro-responsive devices in inductive relation with the track acli at a point relatively near one of the bonds, and signals in operative relation with said electro-responsive devices.

53. In a railway signaling system, a signal, an electro-responsive device in operative relation therewith, a transformer having av track rail and a coil in inductive relation to each other, and a source of inducing current, one of the elements of said transformer being supplied by said source and the other supplying said electro-responsive device.

54. In a railway signaling system, the track rails, an electro-responsive device in operative relation with the same, a source of alternating current supply, and a transformer intermediate said source and said electro-responsive device, one element of said transformer including a rail oi" the track.

55. In a signaling system, a traclrway in which the rails are electrically continuous and divided into block sections by cross bonds.

56. In a signaling system, a traclrway the rails of which are electrically continuous and divided into a series of closed track circuits through the instrumentality of cross bonds.

57. In a signaling system, a traclrway, the ra1ls of whiclrare electrically continuous, a series of cross bonds dividing the rails into eas es block sections, means for impressing an alternating current in each track circuit and means normally energized by said impressed current and adapted to control a signal or signals.

58. In a railway block signaling system a closed track circuit and a source of signaling current supplying the same, a signal, a signal controlling electro-responsive devices, and means for operating the same to set the signal responsive to a movement of a ve hicle over a short portion of the rails at the end of the block, said means deriving its en ergy from a portion of said track circuit having an impedance to said signaling current of the order of magnitude of the short portion of the rails over which the vehicle must move to set the signal.

59. lln a block signaling system for elec- .ceive its operating energy therefrom and be effectively controlled by said energy.

60. In a railway signaling system conductively continuous rails, sources of signaling current feeding the rails, electromagnetic devices, signals controlled thereby, and means cooperating with stretches of the rails for energizing said electromagnetic devices, the energy thus delivered to said devices being proportional to the length of said stretches and said stretches being of a length sufficient to effectively energize said devices When the normal degree of energy from said sources is present in said stretches.

61. In a railway signaling system, con ductively continuous rails, sources of signaling current feeding the rails, electro-responsive devices controlled thereby and means cooperating With stretches of the rails for energizing said electro-responsive devices, the energy thus delivered to said devices being proportional to the length of said stretches, and said stretches being of length sullicient to effectively energize said devices when the normal degree of energy from said sources is present in said stretches.

62. In a railway block signaling system, a source of signal controlling current, a track circuit the rails of which include a long stretch supplied at one end by the source and a short stretch connected to the other end of the long stretch, and electroresponsive signal controlling means cooper" ating with said short stretch and elfectively energized when current from said source flows throughout said short stretch, the energization decreasing substantially proportionately as said short stretch of rail is progressively short-circuited by a passing train.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing Witnesses.

CLYDE J. COLEMAN.

Witnesses RICHARD Eran, EDWIN Snsnn.

topics or this patent may be obtained for five cents each, by addressing the commissioner of latenta, Washington, I). G.