US1879616A - Railway traffic controlling apparatus - Google Patents

Description

, Sept. 27, 1932. A. E. HUDD 1,879,616

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Sept. 25. 1929 2 Sheets-Sheet 1 N Q A 22. a

Sept. 27,1932. A. E. HUDD 1,879,616 l RAILWAY TRAFFIC CONTROLLING vAPPARATUS I Filed sept. 25. 192s 2 sheets-sheet 2 RIF-5:1 E. Hudd Patented Sept. 27, 1932 UNITEDSTATES PATENT OFFICE ,di

.ALFRED E. HUDD, OF EVANSTON, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, T0

ASSOCIATED ELECTRIC LABORATORIES, INC., OF CHICAGO, ILLINOIS, .A CORPORA- TION OF DELAWARE` 4 RAILWAY TRAFFIC CONTROLLING APPARATUS Application led September 25, 1929. Serial No. 395,015.

The present invention relates in general to railway traffic controlling apparatus, but is particularly concerned with the provision of trackway equipment for controlling wayside signals in accordance with trafficA con-A ditions, and Vfor controlling cab signal and train control equipment in accordance with traffic conditions in advance Vof the moving vehicles. Y Y

An outstanding feature of the invention has to do with the provision of trackway equipment for transmitting advance indications to a vehicle, ot the condition of the wayside signal atthe entrance of the block which is being approached as the-vehicle progresses along the trackway.

The invention is disclosed in two sheets of drawings comprising Figs. 1, 2, and 2A, which diagrammatically illustrate' sufficient vehicle equipment and trackwayv apparatus embodying the invention to enable` the same to be readily understood. y.

Referring more specifically to the draw.- ings, Fig. 1 shows vehicle equipment of a train control system, such as that disclosed in the co-pending'Hudd application, Serial No. 377,111.8, tiled July 11, 1929. ,This equipment includes a magnetic-pick-up relay PR, suspended from a locomotivetender in such position that, as the tender passes over the trackway, the relay will pass through the magnetic fields of permanent and electro-magnet trackway elements, placed along the trackway, which will cause the relay to actuate its armatures 1071 to 1074 by Vmagnetism picked up byl magnetic flux collector plates secured to the associated pole-pieces 1051'to 1056, respectively. The armatures V1071 to 1074 are held into association with eitherv of their associated pole-pieces by magnetismpof north polarity 'induced in their free ends by small permanent magnets 108. It may be mentioned, however, that these magnets are very weak compared with those placed along the trackway, and therefore, the trackway magnets readilyovercome the control normally exerted on the armatures by the magnets 103. Associated with the armatures 1073 and1074 are a pair of armature restor- .ing coils 108, which when energized, are efconductor` 97 andthe fective to move the armatures 1073 and 107* into association withpole-pieccs 105e inv case these armatures are associated with polepieces 1053 and 1054 when the windings of 108 are energized. Y

An electro-pneumatic valve EPV and an associated whistle W are provided to sound a warning and to initiate an automatic brake application upon de-energization of the electro-pneumatic valve in any desired manner, for example, in the manner described in the copending application referred to.

The lamp signals G, Y, and R under the joint control` of the pick-up relay PR and of an auxiliary relay 110 serve to visually indicate the traiiic conditions clear, caution, and"stop, respectively.

The vehicle equipment is shown in the position which it assumes after passing a signal at yfclear. Under these circumstances the relay 110, electropneumatic valve EPV and clear indicating lamp G are all energized.

.The circuit of the electro-pneumatic .valve EPV extends romqthe positive terminal Vof the vehicle battery; VB, through the break contacts of the push-button PB, conductor 112, through the contacts and armatures 107 4 and 1073 in series, overconductor 96 and through the winding of EPV back to the negative terminal of battery, supplied to the common conductor 97. v y

i The circuit for relay 110, and the lamp Gr extends from the positive side of the vehicle battery on conductor 112, through the contacts and armature Y 107', conductor 118,

`armature 107 2 and its lower contact,to conductor 95, where theV circuit divides, one branch extending through the lower winding of relay 110 to conductor 97 andthe negative terminal of the battery, while the other branch extends through clear lamp G to negative terminal of the battery. 'd Y The trackway magnets 131,1?2, and P3 are simply groups of permanent magnets enclosed in an appropriate assembly, such for example, as that disclosed in the co-pending application referred to, and are arranged to iniiuence armatures of the pick-up relay PR by inducing magnetic flux in certain iux collector plates and pole-pieces thereof.

The trackway electromagnets E1 to E3 may be of the eneral type of those disclosed in the copen' ing application 'referred to, and simply consist of a core having a pole-piece at each end thereof and a third pole-piece between the two windings. These electromagnets, when energized bycurrent flow in `one direction, generate magnetism of north polarity at their outer pole-pieces, and of south polarity at their middle pole-pieces, and when energized in the reverse direction generate magnetism of south polarity at their outer' pole-pieces and magnetism ofnnorth polarity at their middle pole-pieces. These magnets act-uate the pick-up relay PR of the vehicle by inducing magnetisminto all of the polepieces 1051 to 105.

The trackway equipment shown in Figs. 2 and 2A comprises the circuits and apparatus of one` block C-'D with the signal control circuits and apparatus for controlling trackcircuits in the rear of Vsignal Yposition S omitted, as,suc'h apparatus would merely du pli'cate that shown at the entrance of block D-E. For similar reasons only suliicient ap aratus is shown at the block in advance of -E as is necessaryto enable a complete showing of the cirfcuitsand apparatus at the ventrance of block D -E to be made. In order to voidunnecessarily complicating the dis- 'closure no trackway magnet equipment has been shown `at the left of the entrance to blopgk C-D nor in any location in the block D- Y Y The block extending from C-D is divided into three insulated track-sections, while 'the block D-E is divided into two insulated tracksections. The number of track-sections in a block as well as the lnumber of advance signal indicating positions are determined by 'roadway and traiic requirements. Each track-section is provided with a track relay connected across the rails at the entrance end ofthe section. These track relays are designated T with an appropriate exponent. A suitable source of batterysuch as the track battery 4 extends across the other end of e'ach track Vsection in series with a resistorB, and

if 'an advance indication is provided, also with an y'approach relay. The approach relays are designatedA with a suitable' -exponent. At'each signalling position aline relay isalso provided. Two'such relaysL4 .and L6 are shown. -Also at eachsignal location a signal controllinv relay such as C4 is provided. A pole-c anging relay `PC is also provided at 'each signal .location and functions to control the direction 'of current supto the electromagnet trackway elements f1 to E'3 in a manner which will subsequentyly be made clear. Other block sections obposition it assumes when at least two blocks in advance of D-E are unoccupied. Under clear traiic conditions the track relays are all energized, but the associated approach relays are de-energized owing to the comparatively high resistance of the track relays. The line relay L4 is energized over a series circuitincliuding the signal control relayG This circuit extends from the positive terminal of battery LB4, conductor 11, armature 13, and contact of track relay T4 through the winding 'of L4, line conductor 23, signal control relay C, the contact and armature of track relay T overthe common conductor 25 and conductor 12 to the negative terminal of the battery LBt. A similar circuit exists for signal control relay C4 and line relay L. Each line relay functions to prevent the energization of any lamp of the associated signal when there is no vehicle in the preceding block.y Each'signal control relay functions to determine which of the signals G or Y will be energized when a train enters the block to the rear of the associated wayside signal, and when energized also prepares an 'operating erirccuit for the associated pole-changing relay With the circuits and ap aratus as illustrated, a train entering trac -section TS 'of block C-D causes the track relay T to interrupt the traced circuit including relays C and Li and due to the increased current liow, caused by shunting out the track relay, effects the energization of the approach relay A2. The line relay L4, upon becoming deenergized, at its armature and contact completes a circuit from the positive terminal of battery LB, over conductor 11, the armature and contact of L", the armature 1li and front conta'ct'of track relay T4, conductor 17to the armature and contact of signal control relay C4, where the circuit devices, one branch extending through the lamp G- of signal S4 to conductors 10, 25, and 12 to the other terminal of battery LB?, and the other branch extending by way of the winding of the polechanging relay PC, conductor 9, conductors 25 and 12 to the battery LB4. The lamp Gr of signal S4, therefore, lights-up the instant the train enters the first track-section of block CD to display a clear indication. The pole-changing relay PC, upon becoming energized, owing to the energized condition of the approach relay A2, completes a circuit for the electromagnet track element E1. This circuit extends from the positive terminal of the train control battery TG, through the upper armature and upper contact of the pole-changing relay, the lower Contact and armature of track relay T4, conductor 24, the armature and contact ci approach relay A2, the lower and upper windings of trackway electromagnet E1, and over the common conductor 25, branch conductor 8, and upper contact and lower armature of the pole-changing relay PO back to the other terminal of the train control battery. The Current flow through trackway element E with the polechanging relay-PC energized, is in the proper direction to generate magnetism of north polarity at the upper and lower pole-pieces and of south polarity at the middle pole-piece of this element.

When the train enters track-section TS2 it causes the track relay T2 to drop its armature, thereby interrupting the circuit of the approach relay A2. The armature of T2 at its back contact also places a shunt across the rails at the exit end of track-section TS1 as a further precaution against the track relay T1 being again operated until after all track-sections of block O-D have been cleared by the passing train. The approach relay A2 in dropping its armature interrupts the traced circuit through the trackway element E. The entrance of the train into the traclcsection TS2 also causes the approach relay A"1 tooperate and complete the circuit of the trackway electromagnet element E2 in the same manner as was the circuit completed for E1 whenthe train entered track section TS1. l Y

When the train enters track section TS3 the track relay T3 drops its armature which, like the track relay T1, interrupts the cirf cuit of the associated approach vrelay, and places a shunt across the tracks rails at the exit end of the track section TS1. Obviously, therefore, the track relays T1 andT2 do not again become energized until the 4train clears track-section TSE'. When the train enters track-section TS3 the approachrelay A* at the eXit end of the section also becomes energized and completes the circuitrof the electromagnet track element E3 in the same maiiner as did the corresponding relay at the exit end of the former track section. i

When the train enters track-section TS4 f the track relay T* becomes deenergized, at

armature 13, interrupts a second point in the series circuit of control relayC1 at the entrance of block O-D and of the line L4 at the exit end of this block, so that these relays remain de-energized untilrthe block C-D has been cleared by the train and at armature 14 interrupts the circuit of lamp G of signal S4 and of the pole-changing relay PO, and at the back contacts of this armai ture completes a circuit for` the lamp R of the signal S4. This ylatter circuitextends from the positive terminal of battery LB?, over conductor 11, the armature and back contact of line relayL, armature 14 and its backcontact, conductor 19, the lamp R, and conductors l0, 25, and 12 back to the other terminalv of the battery L-B. The track relay T4L also, at its armaturefl, in-

terrupts the circuit of signal control relay C4 and line relay Le, and these relays ac cordingly become deenergized, and atits lowermost armature 'T1 opens a point in the operating circuit of the-trackway elements y E1 to E3, so that another train passing over the track-sections TS1, TS2, andTSS, while the block D-E is occupied will not bring about the energizat'ion of these trackway electroniagnets. The signal control relay C4 in dropping its armature interrupts a second point in the circuit of lamp G of signal S4 and of the polechanging relay PC and prepares a point'in the circuit of the lamp Y of signal S4. i i

When the train clears track-section TS5x the track relay T3 again becomes energized,

which, in turn, causes the energization of` f track relays T2 and T1.V inthe order named.

When the train enters track-section TS5 the track relay T5 drops its armature to interrupt the current supply to `the track-rails o1' the section TS* and to'place a shunt across the rails thereof. Obviously if this location of the trackway is to be equipped with means trackrelays TA1 and T5 again become energized.` When this occursthe track relay T4, at its armature 13, reestablishesthe series circuit includin line rela L4 and sional cong y n trol relay C', at its armature14 interrupts the circuit of the lamp R of signal S1 and at the frontV contacts of this armature closesa v second point in the circuit of lamp` Y of signal S4. This latter circuit is now maintained open, however, at the varmature of line relay L4. The track relay'T4 also at its armature 15 closes a'poiiit in the series circuit of signal control relay O4 and of line relay L6, sothat when the train clears the neXt block in ad- Vance of D-E this circuit will be again reestablished; and at its lower armature again closes the common train control battery circuit Which supplies current to the trackway electromagnets E1 to E3. Obviously, when the train clears the block in advanceof D-E the signal control relay Oi is again energized, with the result that the multiple circuits of lamp G of signal S1 and of the pole-changing relay PO are again prepared.

It will now be assumedthat there is a train standing in track-section TSG or in some other track-section of the block immediately in advance ofthe D-E and that a second train enters and passes through the block ODQ Under the conditions assumed, the

track relay Te will .be de-energized and, conscquently, the signal control -relay C4 will have prepared a circuit for lamp Yr of signal S. -Therefore, when a second train enters track-section TS1 and track -relay T1 drops its armature to interrupt the traced circuit of signal control relay C1 and of line control relay L, a circuit is completed for the lamp Y of signal S4 instead of lamp Gr of this signal and for the pole-changing relay.

The Circuit extends from the positive terminal of battery LB4, over conductor 11, the varmature and contact of L4, armature 14 and its front contact, conductor 17 the armature and back contaetof signal control relay C4', lamp Y and conductors 10, 25, and 12 to the negative terminal of the battery LBt. The caution signal St is, therefore, displayed when the train enters the block C-D. The same eireuitchanges take place as the train progresses through Vthe block as take place when the signal S4 is at clear, but since the pole-changing relay PG is de-energized under the caution traiiic condition, the current flow through the trackway electromagnets E1 to E3 as each of these are encountered will be in reverse direction to that formerly and, consequently, when these electromagnet traekway elements are energized they will, under these circumstances, generate magnetism of south polarity at their outer-pole-pieces, andfof north polarity at their middle pole-pieces. When the train clears the block C-D the signal apparatus and'circuits of that block function in the same manner as formerly described.

It will now be assumed thatY a train enters the block'C-D andA passes there-through, while a train is standing in one of the tracksections of block D-E. When a train is standing in either of these track-sections the trackrelay T4 is, of course, ole-energized, and, accordingly, has at its armature `141 Completed the circuit of the lamp R of sig- -nal S4; and at its lower armature has interrupted the train control battery feed supply for the electromagnet trackway elements of block C-D. Therefore, when the train enters and passes through the various tracksections of block C-D and the associated approach relays become energized no circuits are completed for Vthe trackway electromagnets of these track-sections.

From the foregoing circuit description it Will be obvious that when a train approaches and passes through the block C-D 4under clear traffic conditions, such conditions eX- isting when block D-E and the block in ad- Vance of D-E are both unoccupied, the electromagnet trackway elements E1, E2, and E3 are successively energized by current flow in one direction; when atrain passes through the various sections of block C-D with the signal-S* displaying a caution indication, indicating that the 'blocks C-D and D-E, are

unoccupied but that the block in advance of D-E is occupied, the current flow through the electromagnet track elements E1, E2, and E3 will be in the reverse direction; and that when a track-section ofk blockY D-E is occupied and a train passes through the various sections of block C-D no current will flow through the trackway electromagnets E1, E2, or E3.

Vith the foregoing facts in mind consideration will now be given to the effects produced in the vehicle equipment as a train passes over the various sections of block C-D under clear, caution, and stop condition of the signal St, respectively.

As the piek-up relay PR passes over the permanent magnet track element P1 magnetism ofsouth polarity is induced in the pole- pieces 1051 and 1053, or in the pole- pieces 1052 and 1054, depending upon the polarity of the permanent magnet P1. rlhe operation of either pair of armatures 1072 and 1074 or 1071 and 1073 brings about theV same circuit changes, and it will, therefore, be assumed that the magnet P1 as well as the other permanent magnet trackway element shown are of the proper polarity to cause armatures 1071 and 107 3 to be operated into engagement with their pole- pieces 1051 and 1053, respectively. The armature 1073, in operating interrupts the traced circuit through the electro-pneumatic valve EPV, thereby causing the same to become deenergized and initiate a brake application, and at the same time causes the whistle-VV to sound. The armature 1071 interrupts the cireuitpa-ssing through the lower winding of relay 110, and the clear indieating lamp Gr in multiple and, accordingly, the lamp Gr is extinguished, andthe relay 110 de-energized. The Ystop indicating lamp R does not light-up, however, as its circuit is novi7 opened at the armature 107 3. rEhe trackway eleetromagnetE1 is located a distance in advance of P1 which requires less than a sixsecond period of time for the train to travel the distance between them unless the vehicle is traveling at a very low speed so that it is passedY over before a brake application can actuallyoccur. When the traekway electromagnet E1 is encountered by the pick-up relay, since the outer pole-piecesof the'eleetromagnet are of north polarity and the middle pole-pieces thereof is of south polarity, this magnet will be effective to restore the armatures 1071 and 1073, because the trackway electromagnet E1 induces magnetism of north polarity in the pole- pieces 1051 and 1053 and, therefore, repels the armatures 1071 and 1073. It also induces magnetism of north polarity in the pole- pieces 1052 and 1054, so that should these armatures have been operated they would have also been restored at this time. The armatures 1071 and 1073, upon becoming restored, simply restore th-e condition of vehicle equipment existing prior to the encountering of trackway element P1. The momentary sounding of. the whistle, however, and the re-lighting of the lamp G in the cabv of the vehicle serves to inform the engine-man that the signal at the entrance to block D-E is displaying a clear indication, and that the train may proceed at full speed. The trackway elements P2 and E2`control the vehicle equipment in the same manner as did 19 the elements P1 and E1. Likewise, at the exit end of the track section TS3 the same operations of the vehicle equipment occur.`

Tt will now be assumed that a train enters block C-D with the signal S1 displaying a clear indication, but that there is also a train standing in track-section TSG or some other track-section of that block. Under these circumstances it will -be recalled that no circuit exists for the pole-changing relay PG at signal position S4; consequently, the

train passing through blockC-D successively energizes electro-'magnet trackway elements E1, E2, and E3 in the proper direction to cause them to generatemagnetism of south polarity attheir outer pole-pieces and magnetism of north' polarity at their middle pole-pieces. The pick-up relay in passing over the permanent magnet trackway element P1, as before, initiates an automatic brake application and eXtinguishes the green lamp G formerly displaying a clear indication in the cab. Affew seconds later, however, the pick-up relaypasses over the electromagnettrackway element E1. When this occurs since the electromagnet trackway element now generates magnetism of south polarity in its outer pole-pieces, it induces magnetism of south polarity in the pole-pieces 1051 to 105, inclusive, and since its middle pole-piece is of northv polarity it induces magnetism of north polarity in the inner pole-pieces 1055 and 105 which assist the attractive effect produced in the pole-pieces 1051 to 105* by tending to repel the armatures. The armatures 1072 and .1071, therefore, also move into engagement with their outer pole-pieces. Armature 107 4, in operating, merely breaks a Y second Vpoint in the traced circuit for the electro-pneumatic valve EPV, While the armature 1072, in addition t0 breaking a second point inthe traced circuit for the clear indicating signalG and lower winding of relay 110, establishes a circuit for the caution signal Y and upper winding a relay 110, This circuit extends from the positive terminal of the vehicle battery VB, through the break contact of the pushbutton PB, conductor 112, the upper contact and armature 1072, conductor 113, the armature 1071 and its lower contact, conductor 1111, and the upper winding of relay 110 and caution signal Y in multiple to the negative terminal of the battery VB. Accordingly, relay 110 is immediately energized to maintain the circuit ofthe stop signal R open and the caution signal Y is lighted to inform the engine-men that the wayside signal S* at the entrance to the next block in advance is .displaying a caution indication, and that they should proceed with caution until amore favorable signal isreceived in the cab. The display of the caution signal in the cab instead of the clear signal also advisesthe enginemen that acknowledgement of the restrictive indication must be made at once to avoid an automatic brake application by momentarily operating the push-button PB. The pressing 0f this button interrupts, at its backkcontact, the'circuit of the lamp Y and relay 110 while this .push-button at its front contact completes a circuit through the armature restoring windings 108, causing the armatures 107s and 1074 to be restored to their normal position in Whichthey are shown. The restoration of these armatures simply causes the previously traced circuit through the electropneumatic valve EPV to be re-established, and serves to prevent an automatic brake application occurring in the manner described, for example, in the co-pending application referred to. A i v A If the train remains standing in the block in advance 'of D-E the same circuitchanges will be brought about in the vehicle as it passes over the trackwayelements at the exit ends oftrack-sections TS2 vand TSS, respectively. It will be assumed, however, that the train in the block immediately in advance of D-E clears such block prior to the time that the pick-up relay in the following vehicle passes over the trackway elements P2 and E2. Under 'these circumstances the signal controlrelay C4 will be energized as will also the pole-changing relay PC. Consequently when the pick-up relay PR passes over the electromagnet trackway element E2, instead of-causing the caution lamp Y to be displayed in the vehicle cab, will restore the operated armatures to the position shown, causing the electro-pneumatic valve EPV to be again energized and .the clearsignal G to be again displayed. lThe -.signal change in the cab vinforms the engine-man that the block signal in advance has changed from a caution to a clear indication, and that the train may proceed at full speed. y

If thejtrain in advance of block D-E for some reason backs into block D-E after the the following train receives the caution indication in the-cab as a result of having passed .trackway' element E1, the trackway relay T4 will be de-energized with the result that no current will be supplied to the trackway device E2 when the pick-up relay passes thereover.

loo

Undervsuch circumstances when the train passes over the permanent magnet moved by the permanent magnet P2`-i. e'.

armatures 107l and 107 .2 will be in engagement with their respective lower contacts. Consequently no circuit exists for the relay 110 or '-for the signal Y, but instead stop signal lamp R is bridged in multiple with the winding of the electro-pneumatic valve EPV, and, accordingly, lights up to display a stop indication in the cab. The displayof the stop indication at this time informs the engine-men that they must proceed with extreme cautionV because the block in advance is occupied. What is claimed is:

1. In a train control system, a vehicle equipped with a device responsive to impulses transmitted from the trackway, a stretch of trackway divided into a plurality of block sections; a block section in said stretch equipped with trackwaymeans for periodically inductively transmitting brake initiating impulses to said device, irrespective of ytraiic conditions in advance of said block;

and a single electromagnetic trafiic controlled. trackway element encountered, subsequent to the initiation of each brake application impulse to variably modify the condition of said device in accordance with traffic conditions in the blocks in advance.y

2. In a train control system, aV stretch of track divided into a plurality of' block sections, and traffic controlled vtrackway electromagnets distributed along certain of said block sections for each transmitting an impulse to a'vehicle passing thereover to produce signal indications in said vehicle in acf cordance with the traiiic conditions'of a plurality of said block sections in advance, said electromagnets each having a single core equipped with three pole pieces.-

3. In a train control system, alstretch of track divided into block sections, a block in said stretch further vdivided into a plurality of insulated sections, a track relay connected across the rails at the entrance o f each section, an approachv relay and' battery connected in series across the rails at the exit end of each section for causing the energization of said track relays while their respective sections are clear and operative by an increase of current flow caused by such section beingv occupied; a permanent magnet and an electromagnet trackway element placed along the trackway, in the order named, at the exit of each section for transmitting train control impulses to passing vehicles; circuits for said electromagnet elements, and means including the respective approach relays for completing the circuits of said electromagnet elements successively as a vehicle passes through said block-when the next block in advance is unl of insulated sections, a track relay connected across the rails at the entrance of each section, an approach relay and battery connected in series across the rails at the exit end of each section for causing the energization of said track relays while their respective sections are clear and operative by an increase or' current iiow caused by such section being occupied; a permanent magnet and an electromagnet trackway element placed-'along the trackway, in the order named, at the exit of each section for transmitting train control impulses to passing vehicles; circuits for said electromagnet elements, and means including the respective approach relays for completing the circuits Yof said electromagnet ele- Y ments successively as a vehicle passes through said block when the next two blocks in advance are un-occupied.

5. In a train control system, a stretch of track divided into block sections, a block in said stretch further divided into a plurality of insulated sections, a track relay connected across the rails at the entrance of each section', an approach relay and battery connected in series across the rails at the exit end of each section for causing the energization of said track relays while their respective sections are clear and operative by an increase of current flow caused by such section being occupied; a permanent magnet and an electromagnet trackway element placed along the trackway, in the order named, at the exit of each section Jfor transmitting train control impulses to passing vehicles; circuits for said ioc electromagnet elements, means including the f respective approach relays for completing the circuits of said electromagnet elements successively Vas a vehicle passes through said block, and means depending upon the occupied or un-occupied condition of the second tionof said electromagnet and for energizing f the electromagnet at the exit end of the secn tion in advance as the vehicle enters the latter section, and traiiic controlled' means Jfor determining the direction lof current flow through said magnets. v I l 7. In a train 'control system, a stretch of lll trackway divided into block sections, Wayside signals at the entrance to each section for displaying clear, caution, and stop indications, respectively, a vehicle on said trackway also provided with clear, caution, and stop signals, magnetic induction trackway means for causing said cab signals to display signal indications corresponding to the indications displayed by the wayside signals at the time the block is entered providing such signals are at clear or caution and for wiping out any prior operated cab signal if the wayside signal is at stop, other magnetic inductive trackvvay means eective as the vehicle passes through such block to cause the vehicle signals to periodically repeat the signal displayed at the entrance of the next block in advance ii and only if such signal is at clear or caution, and manually controlled means on the vehicle operative subsequent to the wiping out of any prior operated signal subsequent to passing a wayside signal at stop for preventing an automatic brake application and for causing the cab signal to:

indicate stop.

8. In a trackway system divided into block sections, each provided with wayside signalling equipment, trackway equipment at the exit of a block, for wiping out any existing cab signal and for then reproducing in the vehicle passing thereover, a signal indication corresponding to that of the wayside signal at the entrance to the next block in case such wayside signal is at clear or caution, other -1 trackway lmeans to the rear of the first mentioned trackway means for also wiping out any existing cab signal and for then reproducing an advance indication in the vehicle ci the condition of the signal at the entrance to the next block only in case it is displaying a clear or caution indication, and manually controlled means operable after passing a signal at stop for preventing an automatic Y brake application and causing the display of a stop signal in the vehicle.`

9. In combination with a stretch of trackway divided into a plurality of block sections, wayside signalling apparatus at the entrance to each blockfordisplaying clear, caution, and danger traiiic conditions, respectively, trackway means at exit end of the preceding block for causing said wayside signal indications to he reproduced in the calo of a vehicle entering a block only when such signal indicates clear or caution, other trackway means in said preceding block for causing the signal indicationsof the block in advance of it to be periodically reproduced in the vehicle as it passes through the preceding block only when such signal indicates clear or caution, and vehicle carried means controlled manually to cause the display of a stop indication thereon subsequent to passing a wayside signal at stop. Y

l0. In a train control system, a stretch of track divided into block sections, a block in said stretch further divided into a plurality of insulatedsections, a track relay connected across the rails at the entrance of each section, circuits for causing the energzation of s aid track relays while their respective sections are clear, a permanent magnet and an electromagnet trackway element placed along the trackway, in the order named, at the exit of each section for transmitting train control impulses to passing vehicles, and circuits for said electromagnet elements under control of said track relays and completed successively as a vehicle passes through said l Iof said track relays while their respective sections are clear, a permanent magnet and an electromagnet trackway element placed along'the trackway, in the order named, at

the exit of each section for transmitting train control impulses to passing vehicles, circuits for said electromagnet elements under control o said track relays and completed successively as a vehicle passes through said block when the next block in advance is unoccupied, and traiiic controlled means for def termining the direction of current How through said electromagnet elements.`

In witness whereof, I hereunto subscribe my name this 18th day of September, A. D.

1929. v v ALFRED E.' I-IUDD.`

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