US1766543A - Track relayless-train-control system - Google Patents

Description

June 24, 1930. w. H. REICHARD TRACK RELAYLESS TRAIN CONTROL SYSTEM Filed May 29, 1925 3 Sheets-Sheet l IYVENTOR. t I

- TORNEY June 24, 1930. w. H. REICHARD TRACK RELAYLESS TRAIN CONTROL SYSTEM Filed May 29, 1 3-Sheets-Sheet 2 m MM U) m E l g u u U 1] a5 P J k N 2 Yw [1| NVENTOR. 0 M M; LE BY 4 I '1 1 i A TORN June 24, 1930. w REICHARD 1,766,543

TRACK RELAYLESS TRAIN CONTROL SYSTEM Filed May 29, 1925 5 Sheets-Sheet 3 .8 t a L I ';SJWV U f v '2 2 m g E- 0 w l' 6 (\l Ll:

O U U l 2 m w h "Qww o "W i? o\ M I m w 4 F m KENTOR.

w I KW am QJ'JTORNEY I Patented June 24, 1939 UNETEB STATES PATENT GFFICE VJADE H. REIGH'ARD, OF ROCHESTER, NEN YORK, ASSIGNOR T6 GENERAL BAIIAVAY SIGNAL COMPANY, 0E ROCFESTE-Pt, NEW YGEK TRAGK R ELA-YLESS-TRAIIL CQNTEOL SYSTETE Application filed May 29, 1925.

This invention relates to train. control systems for railroads, and more particularly to systems of the continuous inductive control type.

In the application of automatic train: con.- trol to railways it is not only necessary to ascertain whether there is a train moving in the same section in which a particular train is moving, but it is also necessary to assure that there is no train less than braking distance beyond the exit end of the section in question and. in accordance with the present invention it is proposed to provide a continuous inductive control system to detect such train including insulated blocks in which no track relays are required.

Generally speaking, it is proposed to manitest the presence of a train in a block in advance of ablock in question by transformer action instead of relay action, by conducting a current derived from a transformer ted by current from the track circuit of the block ahead through a distinctive circuit associated with the block in question. More specifically, it is proposed to divide the track into blocks in the usual way and to provide each block with a simpie): or line circuit including the two track rails in multiple and with the usual track circuit including the two track rails in series, and connect the simplex circuit of one block to the track circuit of the block next in advance thereof by a suitable iron core transformer.

Other objects, purposes and characteris tic features of the invention will in part he pointed out hereinafter and in part be ob vious from the drawings.

in describing the invention in detail reference will be made to the accompanying drawings in which Fig. 1 illustrates trachway and car-carried "t )paratus of a train control system embodymg the pr sent invention, in which currents flowing in two distinctive trackway circuits which are displaced in phase are adapted to be detected on the car, amplified and applied to a polyphase relay;

; i snows r wa an F a 1A l t ack L )aratus ider tical to that shown in Fig. 1 except that the Serial No. 33 .683.

phase relation between the currents of a block is reversed;

Fig. 2 illustrates a system similar to that shown in F ig. 1 in which the flow of current in the two trackway circuits is detected by two separate single phase relays;

Fig. 3 illustrates a. system similar to that shown in Fig. l in which the track circuits of successive blocks are energized by different phases of a polyphase transmission line; and

Fig. 4 illustrates the trackway apparatus necessary to set up non-train-control territory conditions on a train employing the car-carried apparatus shown in. Fig. 3.

Trackwag apparatus (Fig. 1)

Referring particularly to Fig. 1 for the train control system of this invention the track rails 1 are divided by insulating joints 2 into blocks in the usual manner, one block I and the adjacent ends of the two other blocks H and J being shown. The normal direction of traffic is in the direction indicated by the arrow. Since the various blocks are assumed to be equipped the same, like parts of the equipment for each block are designated by like reference characters having distinctive exponents.

Using the reference characters for the block I, at the exit end of each bloclcis a track transformer 23, having its secondary winding connected through the usual track circuit impedance 5 across the track rails in the usual. way. Instead of the usual track relay connected across the entrance end of each block. the present arrangement considering the block I employs a transformer 6.7 which for convenience may be called a line phase or simplex transformer. This transformer 67 has its primary winding; 7 connected across the track rails at the entrance ot the corresponding block and has a middle tap brought out from its primary winding. The secondary winding 6 of this transformer 6-7 has one end connected to the midpoint of a balanced inductive reactance 8 connected across the tracks rails at the exit end of the next block H in the rear,

and has the other end thereof connected by a line wire 9 to the tap at the midpoint of the primary winding of the simplex transformer located at the entrance of said block H next in the rear.

If there is no train in the block J, a potential is applied to the primary winding of the simplex transformer 6 -7 which in turn produces a flow of current in the simplex circuit of the block I in the rear, which current flows down through the two track rails in multiple and back over the line wire 9 including the filaments of the wayside signal lamps or devices 21 and 22 In prac tice, the balanced inductive reactance 8 preferably consists of a closed core of laminated magnetic material having a winding thereon with a tap at the midpoint, so that, it alternating current flows from this midpoint to the two outside leads in multiple, this inductive reactance is balanced and the flow of current is limited only by the ohmic resistance of the windings, whereas if a potential is applied across the outside terminals of this balanced inductive reactance, as there actually is in practice by the track trans former 3, only a very small amount of current will flow therethrough by reason of the high impedance of its winding.

From the foregoing it is readily observed that, under clear tratlic conditions, referring to the block I for instance, there is current flowing down one rail and back through the other from the track transformer 3, and another current is flowing down the two track rails in multiple and back through the line wire 9 from the simplex transformer ti -7 the primary of which is supplied from the track transformer 3 (not shown) of the block J next in advance. These currents in themselves are distinctive because one of them flows down one rail and back through the other whereas the other current flows in the same direction in the two rails in multiple.

\Vhilc the car equipment may be so constructed as to respond to these two currents even though in phase, for reasons now well recognized in the art, it is preferred to organize the trackway equipment so as to provide a phase displacement between these two currents in the loop or track phase, and in the simplex or line phase circuit,

The method of obtaining this phase displacement, and the selections of the electrical constants of the tratn equipment to be used. depends upon a number of variable factors, among which may be mentioned the length of the track section, the ballast resistance, the impedance of the current limiting device the leakage reactance of the transformer (3-7 and the bonding of the track rails and track reactance in general.

In connection with this matter of phase relation of the track and line phase currents, it will be observed that the line phase or simplex circuit current of each track section, instead of being energized directly from the transmission line, is ener ized through a transformer 67 from the inter-rail voltage at the entrance end of the track section next in advance. For this reason, the problem of phase displacement becomes somewhat different than that ordinarily encountered in continuous inductive control systems; and the expedients to obtain the desired phase relation may be different. For example, the line phase or simplex circuit may be made highly reactive to obtain the desired phase relation. Also, the trackway circuits and equipment may be organized, with due regard to the variable factors, to obtain the desired phase displacement between the track phase and line phase currents under clear trafiic conditions ahead of a train by utilizing the change in phase relation in the track circuit current which occurs, for well known reasons when a train enters a track section and its wheels and axles afford a very low resistance shunt to the normal ballast resistance. Generally s eaking, for reasons recognized in the art, tie rail voltage at the entrance end of a track section, and thus any current derived from such voltage, as for example, from the voltage applied to the primary 7 of the transformer 67, lags materially behind the inter-rail voltage at the supply or exit end of the track section, due to ballast leakage and rail impedance. This is the ordinary case when no train is present in the track section; but as soon as a train enters the track section. the very low resistance of its wheels and axles so modifies the electrical characteristics of the track rail circuit that the lag of the track circuit current is greatly reduced. Assuming, now, that the intcr-rail potential across the entrance ends of two successive blocks, as I and J, are approximately in phase, and also that the line phase or simplex current of the rear block I whi h is derived through the transformer (3-T from such inter-rail potential of the block J, is likewise approximately in phase with these voltages, then when a train enters the rear block I, the phase lag of the track circuit current in said block I is materially reduced. but the phase lag of the line phase or simplex circuit current is not materially changed, so that there will be a phase displacement betwcen the track phase and line phase currents suitable for influencing the car equipment. Such phase shift by the entrance of the train into a block can ordinarily be used advantageously to obtain relatively large angles of phase displacement. It should of course be understood that the adaptability of the expedients for obtaining phase displacement just described,

meets-s or other well known methods of varying phase relation in different circuits, depends upon so many ditierent variable factors that, in practicing the invention, the particular means or organization for obtaining the de sired phase relation should be modified to suit the existing conditions.

In Fig. 1A, there has been shown a section of tracltway the circuit arrangement and apparatus of which is identical to that shown in Fig. 1, except that the leads leading from the secondary winding of the simplex transformer reversed, so that the phase relation between currents flowing in the track cire .it and the simplex circuit of a particular block are rev rsed as compared with the phase relation of similar currents in the traclrway circuits shown in Fig. 1, for the reason, heretofore explained, and since the various parts are the same those shown in Fig. 1 they have been assigned like reference characters having distinctive ex ponents a.

Car-carrier] apparatus (Fig. 1)

In Fig. 1 of the drawings there has been shown conventionally a railway vehicle by wheels and axles upon which is mounted suitable car-carried apparatus adapted to control the train in accordance with the flow of currents in the two different trackway circuits heretofore described. In front of the first axle of the train is provided a pair of influence receiving elements, each comprising a core 11 having a coil 12 wound thereon. These coils are connected in series so that potentials induced therein due to a current flowing down one rail and back through the other rail are cumulative. These coils are connected to a suitable track loop phase amplifying device Til includ- '1 i-e ampiiivin ing suit: V g tubes or audiions, sources 2*? energy and tle ill-9, which device is acanted to amplify the currents detected he (oils and cause the amplified cur- 1 to flow through the winding ll of a use induction relay llllt. Similarly, i e provided at a suitable point preferably in rear of the ten e two intlu once receiv rents conpi ng cores 15 h ving co which coils c nnected in series so that potentials tuerein due to currents flowing in wo track rails in the same direction in iple are cumulative, these coils in turn cmincctex'l to a similar amplil' *ing do llel'l amplifies these currents and e amplified currents to the windiii l t. The various 'ea apparatus thus ed are such that the phase relaen the currents flowing in wind- 17 the main relay is stantially t 1e same as the phase relation between the track phase and line phase currents flowing along the traclrway. The main relay MR is provided with movable contacts 18 and 19 which are adapted to assume a normal, a reversed and a de-ener gized position respectively depending on the phase relation of the two currents detected flowing in the traclrway circuits and upon whether only one or both of these currents are flowing.

Although these contacts may control any suitable speed restricting or brake control apparatus depending on whether used in connection with a speed control system, and

automatic stop system or a permissive or auto-manual train control system, for convenience preferably only one arrangement is conventionally illustrated.

Under normal high speed clear trailic con ditions in the particular arrangement shown the contact 18 supplies current to the high cam starter magnet SSH of a speed restricting car-carried mechanism of the type such as shown in the patent oi VJ. ii. Howe, 1,717,339, granted June l, 1929, through a circuit leading from one teri inal B of a suitable source of energy having its other terminal connected to a common return wire 0, which circuit is readily traced in the drawings. Also, when the train in question moves over the traclrway apparatus shown in Fig. 1 under clear trailic conditions the contact 19 is in its normal position as shown and energizes the high speed green lamp (ill for indicating high speed clea traliic conditions, whereas if this contact 19 assumes its de-energized position the red or danger lamp R is energized. From the fore going it will readily appear that when the train travels in a clear block in high speed territory, such as shown in Fig. 1, and both line phase and track phase current detected, which currents have a predetermined phase relation, the relay MR will be r gized to its normal position, as she 11, and that the train will only be restricted to a maximum speed limit as shown in the application rcferred to; whereas if this train enters a blocl; in the rear of an occupied block no simplex current will be detected and the relay will assume its de-energized position and restrict the movement oi": the train in accordance with the speed limits imposed by a specr. -(ilistancc cam. Similarly, if the train enters an occupied block after having passed through a caution hloclr the relay MR will continue to assume its deenergized position and will continue to rest ict the speed of the train to a certain minimum value.

Let us now assume that the train has proceeded along the trackway in which the train may travel at a comparatively high speed such as miles per hour employing trackway apparatus as shown in Fig. 1, and e ters low speed territory, such as shown in Fig.

1A, in which the train is not permitted to run at such high speeds, probably by reason of short blocks, bad curves, or the like, and in which the transformer (E -7 has its secondary winding connected to the line phase or simplex circuit of the corresponding block in a manner reverse to that in which the corresponding transformer is connected in Fig. 1. In this low speed territory (see Fig. 1A) the main relay MR will assume its reversed dotted )osition under clear trailic conditions and wil l maintain the low speed cam starter magnet CSL energized instead of the high speed cam starter magnet CSH, and similarly will energize the low speed clear traftic lamp GL, instead of the high speed green lamp GH. The speed distance cam contacts controlled respectively by the high cam starter magnet CSH and low cam starter magnet CSL are preferably connected in multiple so that if either of these cam starter magnets is energized a certain maximum speed limit is setup by the cam controlled by such magnet. These speed limits for con venience may be considered to be and 40 miles per hour respectively. Also, the cam run-out or ultimate speed limit set up by these cams is preferably the same, which may be assumed to be 15 miles per hour.

The arrangements shown in Figs. 1 and 1A thus provide two possible controls for two different kinds of territory affording the necessary visual indication of traffic conditions ahead, Without the employment of track relays or similar movable responsive means along the track.

While the trackway equipment of the present invention in its preferred form does not employ track relays, the distinctive currents in the circuits through the track rails provided for train control purposes may, if desired. be used to provide wayside. signal indications. In the simplified arrangement. shown. two elcctro-responsive devices 2i and 22, at the entrance to each block, are included in the line wire connections of the line phase or simplex circuits of that block and the block next in the rear. These devices it and 2:2 may be, for example, electric lamps giving distinctive indications. when lighted, either due to different colors, relative position. or relative relation to some other lamp or object. Since the lamp or device 21 is connected in the simple); or line phase circuit of the block I. which receives its energy from the tra k circuit of the block J, this .mp 21. indicates whether or not the block J is oecu pied. The other lamp or device on the other hand, is connected in the line phase circuit of the block H and derives its energy from the track circuit of the block I, so that its energization indicates whether or not the block I is occupied. Thus, if neither the block I or the block J is occupied, both of the lamps 21 and 22 will be lighted, this being representative of and to be Interpreted as an indication of clear tratlic conditions ahead. If the block J is occupied, but not the block I, the lamp or device 2'2 is energized but not the lamp 21; and this indication may be taken to correspond to caution trafiic conditions. If the block I occupied. the lamp or device 22 is not energized, and this may be taken to be an indication of danger trafiic conditions. If both of the blocks I and J are occupied, both of the lamps 21. and 22 are de-energi zed which should be also taken as a danger indication. The lamps .21. and 22, therefore, or corresponding, electroresponsive devices, are controlled in such a way that with proper interpretation they can be employed to communicate the usual indications of clear, caution and stop.

Trackway apparatus (F ig. :2)

The trackway apparatus shown in Fig. of the drawings is identical to that shown in Fig. 1. In order to economize in energy consumption the impedance 5 may cons itute largely inductive reactance. This, is however a matter of choice and either a resist.- ance or an inductive reactant-e may be used. as desired.

The car-carried apparatus in the arrangement shown in Fig. 2 of the drawings is the same as that shown in Fig. 1 up to and including the amplifiers LA and TA. In this embodiment a single phase relay T responsive to current flowing down one rail and back through the other rail is connected to the amplifying device TA so that this relay T at all times indicates the presence and absence respectively of current flowing in the usual track circuit of the block occupitd by the train; whereas the single phase relay L is connected to the amplifying device LA and atall times indicates the presence or absence of simplex current flowing down the two track rails in multiple derived from th track circuit of the block ahead. Since the two relays employed in the ari'aiuzciuclu shown in Fig. 2 draw a distinction between track phase and line phase current it is possible to detect on the car whether the train is moving in an occupied or a caution block. so that three condition control is transmitted from the trackway to the car-cai'ri d apparatus. The relays T and L distinctively detect track phase and line phase currents respectively, because line phase urrent which practically equally divided l etween the two track rails cause: the polcntials induced in coils 12 to neutralize ea h other, by reason of the manner in which they are connected in series; and in the same way, the flow of track circuit current flowing down one rail and back through the other. if it at all reaches the coils 16. causes the potentials induced therein to neutralize each other, because these currents flow in oppo- Ill!) site direction in the two track rails and the coils 16 are so connected as to cumulatively detect currents when flowing in the same direction in the two track rails.

In the arrangement shown, the high cam starter magnet HCS of a system such as shown in the application of Howe, 746,578, filed Oct. 529, 19% is energized only when both the relays T and L are energized, whereas the low cam starter magnet LCS is ener ized even though the line circuit of the particular block in which the train is moving is Clo-energized. That is, the high cam starter magnet HCS is only energized under clear traflic conditions, the low cam starter magnet LCS is energized under both clear and caution tratlic conditions, and both oi these cam starter magnets are de-energized under danger tratlic conditions. Similarly the green lamp G is energized under clear tralii'c conditions, the caution lamp Y is energized when the line phase circuit is die-energized and the track phase circuit is still energized that is, under caution trallic conditions, and the red lamp B is energized when the track phase circuit is shunted by another train ahead in the same block, namely under danger trafic conditions.

Operation (Fig. From the foregoing the operation of the system and the restrictions set up thereby during the movement of the train under various conditions of tratiic is readily under-- stood without considering train movements specifically, the speed being restricted from a high to a low value, at which low value tl e train may travel in an occupied block after movement of the train through a cantion block, this'by reason of de-encrgization of the high cam starter magnet 'HCS; and further, de-energization of the low cam starter magnet LCS restricts the movement of the train to this same low speed value after predetermined distance of movement of the train in an occupied block. In other words, the low cam :tarter magnet (ISL abruptly up a minimum speed limit only after a distance of movement in order to take care of dead sections usually encountered at frogs, turn-outs, and junctions between adjacent blocks, as more clearly set forth in the last mentioned l lowc' application.

Tracllrurai a )araf'us F its. Band .4

phase so that the middle wire constitutes the common wire for the two phases, this. current being supplied by the two-phase generator AC illustrated. In other words, in Fig. 3 every other block of the trackway has alternating current applied thereto in identically the same manner, whereas adjacent blocks have an alternating current applied to their track circuit in a manner so that the currents in the circuits of one block displaced in phase substantially 9O electrical degrees with respect to the currents in corresponding circu ts of the next adjacent block. In this a rangement, the constants of the track circu ts are preferably so chosen that the inc phase current of a particular block lags only a very small angle behind the potential of the track transformer of the next block in advance and from which it receives its energy, so that, the phase relation between the track phase current and the line phase current of a block is substantially 90 electrical degrees regardless of whether this block is occupied or unoccupied by a train. Instead of using two phase current, as shown, three phase current may be employed, in which event the leg of the current due to rail impedance and the impedance 5 may be combined with the 120 displacement betwcen phases, so as to result in a phase displacement suitable for controlling the relay MB.

In Fig. l, has been shown a short section of trackway'at the approach to unequipped or non-train-control territory in which no traclzway apparatus for train control purposes is provided. Obviously, suitable means must be provided on the car to permit the movement of the train in suchnon train-control territory and the trackway apparatus shown in Fig. l is provided to set up conditions on the car to permit the train to travel unrestricted so long as it moves in such non-train-control territory. This trackway apparatus comprises a short section of track insulated by joints 2 in the usual manner and having balanced inductive reactances 26 and 27 connected across ihe ends of this short section, and having phase relation between the line phase and track phase'current of this short section is the'reverse of the phase relation between the line phase and track phase current of any of the blocks shown in Fig. This phase relation between the currents flowing in till this short section should be borne in mind in connection with the operation of the car carried apparatus shown in Fig. 3 hereinafter described.

Gar-curried apparatus (Fig.

The car-can'ried apparatus shown in Fig. 3 of the drawings up to and including the main relay MR is the same as that shown in Fig. 1 of the drawings. The difference between the systems shown in Fig. 3 and Fig. 1 is most readily apparent by considering the operation of the system.

Opera/lion (Figs. a and it) From the discussion heretofore given it readily appears that the main relay MR assumes the normal position in which it has been shown when the train travels in an otherwise unoccupied block and the block next in advance is also unoccupied, that is, under clear trafiic conditions, and the cam starter magnet CS is energized and permits the train to proceed restricted only by a maximum speed limit, and that the green lamp G provided for indicating such clear tratlic conditions is also energized. If now, the train enters a caution block in which there is no line phase current present, the main relay assumes its tie-energized position and completes an energizing circuit for the red or danger lamp and simultaneously effects de-energization of the cam starter magnet CS and restricts the movement of the train in accordance with the speed restricting cam associated with this magnet; also, when the train enters an occupied block, the main relay MR continues to as sume its de-encrgized position even if there is line phase current flowing in this block because there is no track phase current 'tlowing to be detected, this current being shunted away by the rain ahead in the same block, :10 that the cam starter magnet CS remains tie-energized and ILSilllh the :aieud 4f the train in an occu a! block to the same minimum value set up at the end of a caution block which may be considered to be the same as heretofore assumed, namely 15 miles per hour.

Let us now assume that the train has reached the end of the section of trackvay equipped for train. control purposes and is just about to enter non-train-control territory. Just before the train enters such nontrain-control territory itenters the short section of trackway shown in Fig. 4, in which track phase and line phase currents are flowing which have a reverse phase relation from that of the currents flowing in the blocks illustrated in Fig. so that the main relay MR assumes its reversed energized position. Under this condition of the main relay MR an energized pick-up circuit is completed for the non-control relay NC, which causes this relay to assume its energized position. As soon as this stick relay assumes its energized position, the front contact 31 of this relay closes a break in its stick circuit, which stick circuit also includes the contact 18 of the main rclay MR; so that, when the train passes off of this short section (Fig. 4) and the main relay MR assumes its de-energized position this stick circuit is completed. In this connection, it should be observed that the nontrain-control territory relay NC is slow acting (conventionally illustrated) and maintains its contact 231 closed while the main relay MR changes from its reversed to its dcenergized position. lVith the non-traincont-rol territory relay NC energized an auxiliary energizing circuit for the cam starter magnet CS, including the front contact 32 of the relay NC, is completed, and with this cam starter magnet CS energized the train may proceed unrestricted except by a maximum speed limit. Also, with the relay NC energized it is indicated to the engineer that he is traveling in non-traincontrol territory and that the safety of the train depends entirely on him. If the train again enters a clear block in train control territory the main relay MR again assumes its energized position and thereby breaks the stick circuit of the relay NC, thereby restoring this relay to normal.

Having thus shown and described several specific embodiments of a train control and wayside signal system employing traclnvay apparatus which does not include track relays or other electro-rcsponsive devices of a similar character, and having described these systems rather specifically; it is desired to be understood that this has been done for the purpose of disclosing the. invention rather than indicating its scope or indi eating the exact form of the invention pref" erably carried out in practice. and that various changes, modifications, and additiom may be made to facilitate the application of this invention to the various dill'erent typrs of systems, such as, automatic stop systems. permissive continuous inductive type train control systems and the like. without departing from the spirit of the invention, or the idea of means underlying the same.

lVhat it is desired to be secured by Letters Patent is 1. In an automatic train control system of the continuous inductive type, the combination of car-carried apparatus dei-zigiawl and organized to detect trackway currents distinctive from each other, and of trackway means for deriving one of these distinctive currents of a section from current flowing in a track circuit of the next section in advance.

2. In an automatic train control system of the continuous inductive type, the combilUt) lltl

lill

nation of car-carried apparatus designed and organized to detect tracltway currents distinctive from each other, and of trac way means for supplying such distinctive currents to each section of the trackway divided by insulating joints into sections in a mar ner so that one of these currents of one sec tion flows in response to the other of these currents in the section next in advance.

In an automatic train control system or the continuous inductive type, the combination of car-carried apparatus designed and organized to detect tracltway currents distinctive from each other, and ot' tracliway apparatus including a plurality of track sections insulated from each other, each having the usual track circuit including the track rails in series, a simplex circuit for each track section including the traclt rails in multiple, and means for inductively coupling the track circuit of one section to the simplex circuit of one of the adjacent sections.

4. In an automatic train control system of the continuous inductive type, the com bination of car-carried apparatus designed and organized to detect trackway currents distinctive from each other, and of trackway apparatus including a plurality of track sections insulated from each other each havin the usual track circuit including the two rails in series and a simplex circuit includ ing the two rails in multiple organized and arranged so that current in the simplex circuit of one section derives its energy iron the rear end of the track circuit of the track section next in advance.

5. In an automatic train control system of the continuous inductive type, the combination of car-carded apparatus designed and arranged to detect the presence of alternating currents displaced in phase and flowing in distinctive trackway circuits, and oi? acltway means for supplying such currents omprising a tracltway divided into sections 3y insulated joints each having two distincive c" 1, and means for energizing one f these circuits of one section by the current wing in the other ot' these circuits of the xe section in advance.

6. In an automatic train control system of the continuous inductive type, the combination of car-carried apparatus designed and arranged to detect the resence o't alternat ing currents in distinctive trackway circuits if alternating currents tlow therein which are displaced in phase, and of trackway means "for supplying such currents comprising a trackway divided into sections by insulated joints each having two distinctive circuits, and means for energizing one of these circuits of one section by electrical energy derived from the other of these circuits of the next section in advance, and means for supplying said other circuit of successive tracl sections by alternating currents having a phase relation such that the phase relation between currents flowing in the distinctive circuits of each track section is substantially the same.

7. In an automatic train control system of the continuous inductive type, the combination of car-carried apparatus designed and arranged to detect the presence of alternating currents displaced in phase and flowing in distinctive traclrway circuits; and of trackway means for supplying such currents comprising a trackway divided into sections by insulating joints each having the usual track circuit including the two track rails in series and a simplex circuit including the two track rails in multiple, and means for supplying alternate track circuits by the same phase of a polyphase alternating current source of supply and supplying the remaining track circuits from the other phase of said source, said circuits being arranged so that the simplex circuit or one section receives its energy from the track circuit oi" the next section in advance.

8. In an automatic train control system of the continuous inductive type, the combination of car-carried apparatus designed and arranged to detect the presence 01 alternating currents displaced in phase and flowin m distinctive tracltway circuits, and or 'trackway means for supplying such currents comprising a trackway divided into blocks by insulatmg oints each having a track circuit including the two track rails in series and a simplex circuit including the two track rails in multiple, and means for supplying alternate track circuits by the same phase of a two-phase alternating current source of supply and supplying the remaining track circuits from the other phase of said source,

and means for inductively coupling the plex circuit of one block to the rear end of the track circuit of the next block in advance, whereby the simplex current is shunt ed away, when the next block in advance is occupied, the track circuit current is shunted away if the same block is occupied by another train ahead, and both of these currents are shunted away if the next block in advance is occupied and the block in question is occupied by another train ahead.

9. In an automatic train control system for railways; the combination of car-carried apparatus including a three-position relay,

means controlled by said relay for manifesting clear trafiic conditions when said relay energized in one direction, for manifesting danger traffic conditions when said relay is (lo-energized, and for manifesting that the train is running in non-train-control territory when said relay assumes the reversed position momentarily and then assumes the de-energized position, means for energizing said relay in response to alternating currents displaced in phase and flowing in two distinctive trackway circuits; and 01" rraclrway means comprising a track divided into sections by insulating joints each having two distinctive circuits, means for energizing one of these circuits of a section by current flowin in the other of these circuits of the next section in advance, means for energizing said other circuit of each of said sections by alternating current in a manner so that the currents in said other circuits of adjoining sections are displaced in phase, and means at the entrance to non-train-control territory for causing said relay to assume the reversed position momentarily.

10. In an automatic train control system adapted for use in two different kinds of ter ritory; the combination of car-carried apparatus including two separate devices controlled in a manner so that only one of these devices can be energized at one time and of which one device is normally energized, these devices when energized setting up different maximum permissive speed limits each maximum speed limit being suitable for one of the two kinds of territory and each if tie-energized further restricting the movement of the train; and of trackway apparatus in certain territory for maintaining one of these devices energized under clear traffic conditions and allowing it to become de-cnergized under adverse trailic conditions, and similar trackway apparatus in other territory for maintaining the other device energized under clear trafiic conditions and allowing it to become tie-energized under adverse trafiic conditions.

11. In an automatic train control system; the combination of car-carried apparatus comprising a three position relay adapted to assume a normal energized position if there are alternating currents flowing in two distinct trackway circuits which have a normal phase relation, assume a reverse position if there are currents flowing in such trackway circuit which have a reverse phase relation and assume a de-encrgized position it one or both of these currents are cut off, speed restricting mechanism including a normally energized electroresponsive device which if de-energized restricts the speed of the train and maintained energized if said relay is in its normal position, a non-train-control territory relay having a pick-up and a stick circuit and connected to have its pick-up circuit closed when said three position relay assumes its reverse position and to have its stick circuit closed it once in its energized position and said three position relay is in its rte-energized position, said non-train-control territory relay permitting the train to proceed in territory where there are no trackway circuits; and of trackway apparatus in train control territory including sections each having two circuits one of which corresponds to the usual track circuit and includes the two track rails in series and the ther of which is a simplex circuit including the two track rails in multiple of which the simplex circuit of one section is fed directly through a transformer by the track circuit of the next section in advance, and means at the entrance to non-train-control territory for causing said three position relay to sume the reverse position for a short distance of travel.

12. In an automatic train control system of the continuous inductive type, the combination with car-carried apparatus designed and organized to distinctively detect the presence of currents flowing in opposite directions in the two track rails in series and the presence of currents flowing in the same direction in the two track rails in multiple, and means for restricting the speed of the train it either of these distinctive currents are not detected; and of t-rackway means for causing the flow of current down one rail and back through the other due to the application of a source of potential connected across the rails at the exit end of a block, and for causing the flow of currents in the same direction in the two track rails in multipain the block next in the rear, the current flowing in the track rails of such lock in the rear being derived from said source connected to the exit end of the first nil-in tioned block whereby no such current flowing in the track rails in multiple of a block will be present when the next block in advance is occupied, and the vehicle will have its speed restricted if there is a train ahead in the same block or there is a train in the next block in advance thereof.

13. In an automatic train control system of the continuous inductive type, the combination with car-carried apparatus designed and organized to detect trackway currents distinctive in character from each other, of trackway means for applying such currents to the track rails in overlapped relation in a manner so that the current of one character is derived from the flow of current of the other character and so that current of both characters are present throughout the entire trackway under clear trailic conditions ahead.

14. In a signaling system for railroads, the combination with a track divided into sections by insulating joints, :1 source of energy connected across the track rails ot each section at the exit end thereof, and means connected across the track rails at the entrance end of each section for illuminating light signals at the entrance end of such section and at the entrance end of the next sew tion in the rear by current derived from the entrance end of such section.

15. In a signaling system for railroads, the combination with a track divided into sections by insulating joints, a source ot energy connected across the track rails of each section at the exit end thereof, and a transformer having its primary winding connected across the entrance end of such section for energizing light signals at the entrance end of such section and the entrance end of the next section in the rear thereof.

16. In an automatic train control system of the continuous inductive type, the combination with car-carried apparatus designed and organized to detect trackway currents distinctive from each other, of a trackway including sections and having means associated therewith for supplying current to the exit end of one of said sections in such a manner that it will be shunted from the entrance end thereof by a train in said section, and means for i e-applying current, derived from flow of current in the entrance end of such section, in a different manner, to the next section in the rear.

17. In an automatic train control system of the continuous inductive type, the combination with car-carried apparatus designed and organized to detect trackway currents distinctive from each other, of a trackway including sections and having means associated therewith for supplying current to the exit end of one of said sections in such a manner that it will be shunted from the entrance end thereof by a train in said section, and means for reapplying current, derived from flow of current in the entrance end of such section, in a diiferent manner, to the next section in the rear, said car-carried apparatus comprising separate relays for distinctively detecting the currents applied and re-applied to said sections of trackway.

In testimony whereof I hereby aflix my signature.

WADE H. REICI-IARD.

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