US1788881A - Train-control system - Google Patents

Description

Jan. 13, 1931. w. w. MACFARLANE 'I RAIN CONTROL SYSTEM Original Fi d May 4, 1916 s Sheets-Sheet 1 William WMa'c/arlane Jan. 13, 1931. w. w. MACFARLANE 1,788,381

TRAIN CONTROL SYSTEM v Original Fild May 4, 1916 s Sheets-Sheet 2 y I I gnventoz $1, fltkvomq 3 nue/wfoz f szcfarlawe 3 Sheets-Sheet 3 2 rl/Ara Wham 7/ Jan. 13, 193 1. w. w. 'MACFLARLANE TRAIN CONTROL SYSTEM Original Filed May 4, 1916 %1, aftowu Patented Jan. 1 3, 1 93 1 PATE T OFFICE I WILLIAM w. MAGFARLANE, or nLKrNs PARK, PENNSYLVANIA, AssIGNoR, Be IQEESNE 5 ASSIGNM'ENTS, T9 TEL UHEONfi-VTZTCH 5t SIGNAL- COMPANY, OF SWISSVALE, PENN SYLVANIA, A CORPORATION OF PENNSYLVANIA raArN coN'rRoL SYSTEM App1ication ea May 4,: 19-16; .erial No. escuee. Renewed. Tii'arch 1,1919.

" This invention relates to train controlling.

systems and more ,particularly'to those systems in which train-carried controlling devices are automatically controlled by track conditions. v

The principal object ,ofthefinvention is to provide a simplified. method for. utilizing crack circuits to continuously control a trail; moving in eitherdirection without theuse of ramp rails or continuous contact rails other than the tratlic rails themselves. The pres ent invention'embodies train controlling de-' vices of the same general type as are disclosed in. my copending application Serial 'No. 825861, filed March 8, 191 6.

i-inother feature of the invention is the provision of an automatic brake operating mechanism lil jXVlllCll atiming device pre- 7 vents the immediateapplication of thebrakes In addition to the track circuit in each block other normally open circuits are employed which are adaptupon the receipt of a danger signal thereby giving the engineer an opportunity to bring the train to a step through means directly under his control. d

Another feature is the employment of means controlled by the presence of'a train in a block for supplying current to the rails of the block to control the train.

Still another feature is the provision of speedcontrolled devices to permit a train to creep into a tram-occupied block at a very low speed, and to prevent the train fromexceeding' apredetermined maximum speed regardless of track conditions.

In order to control the operation. ofthe train governing apparatus a track circuit system partlcularly adapted for use on a s1ngle track railway .is preferably employed.

ordinary normally closed ed to furnish to the rails of the bloclr-aj'train controlling current of a difi'erent character than thatsupplied by the normally closed circuit. Either alternating or direct current may be used in both the normally open and the normally closed circuits providing the current in the different circuits be made to distinguish by some fcharacteristic of phase, frequency voltageor the like. Preferably, however, alternating current is ern-f the invention.

76 and 7 ployed for the normally closed circuit and direct current forjthe normally open train controlling circuits.

In the drawings in which like reference characters designate corresponding parts:

Figure 1 is a general diagrammatic view of a track circuit system embodying part of Figure 2 is a diagrammatic view ofa train controlling system embodying another part of the invention. V

t Figure 3is a longitudinal section takencon the line of Figure 4 showing the valve operating mechanism.

Figure 4: is a view partlyin section and partly in elevation of the brake mechanism taken along the line 44 of Figure 8. v

In the track circuit system illustrated in Figure lot the drawings, the track rails 1 and'EZ are divided into suitable block sections a of the block sect-ion. I A noninductive resistance8 is preferablyinterposed in the conductor 6 to prevent an excessive flow of current from the transformenwhen a train is bridging the rails near the points of connection of the supply conductors 6 and 7 therewith.

Each block section is provided with two alternating current track relays 9 and 10 connected to, the rails at the ends of the block through a the conductors 1l--12 and 8334 respectively and adapted to be normally energized by current from the transformer 3 when the block is not occupied by a train, in a manner well-known in the signaling 'art. lhese track relays are preferably of the type which will respond only to a given frequency of the currentsupp'lied by thevtransformer 3 and will therefore'be immune to direct currenter to alternatlng current of a different frequency irom that in connection With which they are designed to operate. If found desirable, some form of condenser mightbe provided in the connection between each alternating current relay and the track to prevent direct current from interfering with these relays.

The track rails of each block have also connected thereto at opposite ends of the block, the sources of direct current 13 and 14 which supply current for controlling suitable train governing devices preferably mounted on the locomotive of the train and arranged to take current from the rail through contact shoes having direct engagement therewit The current sources 13 and 14 are preferably designed to furnish a current of comparatively low voltage and relatively large volume.

The source 13 is connected to the track rail 1 through the conductor 15 and to the track rail 2- through the conductor 16, contacts 17, conductor 18, contacts 19, and conductor including the resistance 21, to the rai 2. The contacts 17 are adapted to be bridged by the circuit closer 22 which is adapted to be held out of engagement with the contacts when the track relay 9 is energized. When the relay 9 is deenergized, as by the short-circuiting effect of a train in the block, the circuit closer 22 is moved by the action of gravity into engagement with the contacts 1?. Normally the circuit including the source 13 is open at the contacts 17 and is closed at this point coincidently with the entrance of a train into the block and upon the consequent deenergization of the track relay 9.

The contacts 19 in the circuit through the source 13 are normally held closed by a circuit closer Q4: controlled by the track relay 10 of the adjacent end of the adjoining block. The action of gravity will move the circuit closer 24; out of bridging engagement with the cont cts 19 upon the deenergization of the relay 10 caused by the presence of atrain in the corresponding block. Thus, under normal conditions, that is, when no train is in either of two adjacent blocks, the circuit through the source 13 of one block is open at the contacts 17 and closed at the contacts 19.

At the other end of each block the source of current 14 is connected through the conductor 26 to the track rail 1 and through the conductor 27, contacts 28, conductor 29, contacts 30, and conductor 31 including the resistance 32 to the track rail 2. The contacts 28 are adapted to be bridged by the circuit closer 22 when the relay 9 of the adjacent end of the adjoining block is energized, while the contacts are adapted to be bridged by the circuit closer 24 when the track relay 10 is deenergized.

It will be apparent'that, when the insulated blocks on both sides of any given block are unoccupied by a train, the contacts of the train control circuits of the given block which are under the control of the relays in the ad jacent blocks will be closed. Consequently a train which may be present in the given block will have current supplied to its controlling device by the closed control circuit at the end of the block which it is approaching, since the contacts of the control circuits which are governed by the train-occupied block are also closed because of the deenergization of the track relays 9 and 10.

The current supplied by the circuit at the rear of the train will have no effect on the control mechanism 35 carried by the locomotive because of the shunting effect of the wheels and axles of the train which are between the contact shoes 36 and 37 and the source at the rear. It will be clear, therefore, that a train entering the block to the rear will in no way affect the progress of the train in the block ahead but will itself be stopped because of its inability to take current from the circuit at the forward end of the block since this circuit will of course be open at the break controlled by the train '11 the block ahead. Consequently, when two trains are proceeding along the track in the same direction the forward train will not have its progress restricted by the presence of the train in the rear, while, on the other hand, the train to the rear cannot advance into the block immediately to the rear of the one occupied by the forward train. There must always be, then, in the track circuit system disclosed, an intervening clear block between two trains traveling in the same direction so that a following train can by no possibility approach near enough to the train in advance to be in danger of participating in a rear-end collision therewith.

In the case where two trains are approaching each other on a single tracs, since the train in an occupied block opens a break in the train control circuit of block ahead, it will be clear that the approaching train will be stopped as soon as it enters the block ahead of the first train. It will be clear also that, since the second train opens the train control circuit in the adjacent end of the block ahead of it, that the first train will also be stopped as soon as it enters the block ahead of the second train.

Therefore, not only will a train approaching from the rear be stopped when it reaches the block immediately to the rear of the trainoccupied block, but also both of the approaching trains will be stopped immediately upon the entrance of either train into the block immediately ahead of the other train. The result of this is that no train can approach nearer than a block to another train regardless of whether the other train is running toward or away from the first train or is not moving at all. Also of two trains running in the same direction, the following train will be prevented from approaching within, deg-ms,

l ni h be om a den e i s pos tio W llhave no restrictionwhatever placed npon its movemen by the ppre hio he l inetm I .Wil a eer ie e by ei sl hete h. i

asit tr'aa elscreates andcarries withit e 151-0 e t ee which. ext d th t h bloc imme ia e y to the, rea and the a A fathe entwined boloek,

' f e tt l wli qh s.

- r Figure 2 n which thereby setteate %P th epproach of two trians to a position within a blasts-lengthen Q1 7 i he dr w ng s ow a pte elzred e bod ment o e y mict a a apted; t ibe tj l di i the t ack mot y t m qonneet n i h,

reedydes z bedv A tj 5 is shown thetrain controlling relay -which, through the contact shoes, 36 and 37, is. in cont ents, br dgin engagem n w he t ack r eelsi reed-2 As nthe dev c LCIQWMII the QQPQ ies apn i t d' ib refer nc een made his a b ging emeeteeth i j enstruet d t Qfi M1 tEtm y- QWIQ itenC t h n s ee p rent h re h e so: th t sefiie nt current 1 14 .ct' e ted' L t nithreths formed y the wheels and axles to operate the relay '35.]

The of the Qieferably consists of a helical strip oficoplger, or other highly. condiictive material, a f comparatiyely lange crossgsect ionalareg fgl he endsof the C611 tee e ted to massive eppe cabl which: }-1 ead ,to and ate embedded in the contact shoes 36 Thegconlbin ed igess ance th oi fth re ey 35, t e a e 38ai' fd e cqn a t tqeat nd 11s solQW that t e akliae'e Wh ls and ek tcircuited end substantially the entire ciir' nt flow'ndm ,to ipath oileast re sta ce hre gliy he'e tr' Tl elmet tfit fi th? fe t! w l ie egemmt'witli e ontac plat 4 -i then0ni a y .ne g z d eiidi iq of. the

relay. '1' A stop 41 i S -J P IGVided against which fle'eeeae sb e s ii when I ten snet fl w h ete he r let- $1 eq i es plete 4 0i s r e eed y-t e t atun nttol' cir'cuit'wllich a y cl ud es the batter e2, condnc torfiii, conductor imam-s9, Contact P ate $0,, l qn cto t; mat-Tee Centimeter 47 ba to. el teryl The relay 46 is thus energized to hold the'memb r fi e ta t gfllq lb i i tarei gainst the ten lfcentaqts 50 and 5 the e y cles n lc t tiits th g it rate,

' cl l e t e ba tery 4 2; ee i et ii conducto yvithd raw from what 1 ada oted to V battery. it urrent to ener'g1' .9;ethe brake rnagee it shunt e en tree the the safetj la'nip 52at tlie frontcontact 50511161.

through the brake magnet at the front contact 51; The .deenergizationbf the magnet setthe'brake operating mechanism into action. Sinntltaneously with this the red or danger, lam p89 will be lighted and theibell 9,0 actuated by rneans of current sup- .plied from the battery 42, conductor48, conltlCtQQlfl ft conductor 54; ar1nature :49, back 'contact'9l conductor 92, conductor 93, lamp 89, conductor 94=Qto connnon return conductor ,Tand also from conductor 93, to bellQO, conductor v 95,an :l conductor 9.4 to common return conductor 47 back to battery. Thus upon the entrance of a train into a danger Zone, danger signals will be actueted in the and L bra-kc actuating-mechanism will be setintooperation. 1

The brake rnagnet 5 3, to which reference has beenjrnade, is adapted to control a Valve operating mechanism throngh'the connection of the pli tnger core ,58 with vthe lever59 pivotedto astationary support at 60. The valve stemfil, carryingthei alves 62' and 63, adapted tobe held in an elevatedposition by ,the lever 59 when the magnet 53 is energized. ifhe ve r 6 I P re wit a vatt sea 64 tocontrol the flow o'fair from the train pipe 65 through the pipe 66 to the cylinder 67. A iston'68 in the cylinder is connected thronghthe piston rod'69 with the stem 70 on" a brake wolves 71-adapted to control an exha tPe t t et fa n p p w n one: to r te o s x m w cti n of the a t ma ic brake a ue gmeek a w ll a w tlw ra n o pa we by meem f he m w-thr d st 1 lock nut 75f is adapted to lock the-screw in e position. cap 1 9 closes-the end of the cglinder and serves as a nut'throng-h which the threaded stem 77 can he manipulated. The cap'is.

Qyl m t't l hlconstent c i nni at e w th the valve chamber 81- end cylinder 67through the R ese" t a e demise t on at tre v r, o elik e.

preferably detachably mounted onithe end of the cylinder in an suitable nannerjas by mea nsrfof the bayonet j ietinl ci edafiSOin igetese nee. The a The regulating, or timing, cylinder is preferably of such a size that an appreciable interval of time will be required to supply sufiicient air thereto through the comparatively small aperture 83 to raise the pressure in the chamber 72 and cylinder 67 to point necessary for the operation of the piston 68. The extent of the time interval may be regulated by *arying the position of the piston 7 6 to thereby change the volumeof the chamber 72, as wi l be evident.

In order to prevent tie complete exhaustion of pressure from the train pipe followi an action of the automatic brake controh ling mechanism, a spring 8 1 is mounted on the valve stem 69 and bears against a collar thereon to move the piston to inoperative position when the pressure in the brake pipe and chamber 72 is lowered to a certain predetermined mi-nimnm. The degree of pressure exerted by the spring 861 may as varied through moving the slidable abutment memher 80 by means of the adjusting screw 87. Locking bolts 88 are preferably provided for fixing the position of the abutment member when the adjustment has been made.

Provision is made by means of the speed controlled device 96 for allowing a movement of the train under greatly reduced speed when danger conditions exist so that, for example, a train mi ht creep forward into a block occupied by a disabled train for the purpose of giving assistance. The speed controlled device is of the same type as that shown in the companion case in which a frangible bulb 9? containins mercury 98 is caused to rotate through a mechanical connection with a mow ing part, such as an axle of the train. Contacts 99, bridged by the mercury under a very low speed, such two or four miles an hour, are adapted to be electrically disconnected by the action of centrifugal force on the mercury upon an increase of speed above the figure named. Under the minimum speed referred to a circuit is established through the brake control magnet 53as follows: battery 42, conductor 13, conductor #14, conductor 100, contacts 99 and mercury 98, conductor '53, brake magnet 53, conductor 74-, and common return conductor 4:? back to battery.

Current flowing over the circuit ust traced will hold the magnet 53 energized or will. reenergize it, if the speed of the train has been lowered to the permissible rate due to an operation of the automatic brake actuating mechanism. The energized magnet 58 will lift the valve 62 to its seat and lift the valve 63 off its seat in the exhaust port 101 to vent the regulating chamber '72 and cylinder 6'7 to permit the spring 8% to withdraw the piston 68 from valve operating position.

A supplemental speed controlled device is shown at 102 which is similar in construction to the speed controlled device 96 already described. In the speed controlled device 102'however, the contacts are arranged to be disengaged by the mercury only when the vehicle exceeds the predetermined maximum speed at which it is permitted to travel. Under such conditions the magnet 103 in the conductor 10% will be deenergized to open the sup leme-ntai bralze valve 105 and vent the pipe to apply the brakes. This p ration will tare p ace regardless of the exceed the maximum allowable speed even under safety conditions.

What is claimed, is:

1. A systemof train control comprising:

a track divided into insulated blocks, means controlled by the presence of a train in a block to supply current to the rails of the block, and means on the train for short-cirting the wheels and axles thereof and uti- .1 .ing current from said rails to control the train." V

2. A system of train control comprising: a track divided into insulated blocks, means controlled by the presence of a train in a block to supply current to the rails of the block, means on the train for utilizing current from said rails to control the train, and means in both the adjoining blocks for controlling the supply of current to the rails of the train-occupied block.

A system of train control comprising: a track divided into insulated blocks, means controlled by the presence of a train in a block to supply current to the rails of a block, train controlling means, means on the train in bridging engagement with the rails normally held inoperative by current from said rails and operating upon the failure of the supply of current to actuate the train controlling means, and means in another block for. preventing the supply of current to the rails of the train-occupied block.

1. A system of train control comprising: a track divided into insulated blocks, means controlled by the presence of a train in a block to supply current to the rails of a block, train controlling means, means on the train in bridging engagement with the rails normally held inoperative by current from said rails and operating upon the failure of the supply of current to actuate the train controlling means, and means in the block next in advance for preventing the supply of current to the rails of the train-occupied block.

5. A system of train control comprising: a track divided into insulated blocks, means controlled by the presence of a train in a block to supply current to the rails of a block, train controlling means, means on the train for short-circuiting the wheels and axles thereof normally held inoperative by current from said rails and operating upon the failure of the supply of current to actuate the train controlling means, and means in an- ;rai'iic conditions, so that the vehicle cannot n other block for preventing the supply ofcurrent to the rails of theLtrain-occup-ied block. 6. A system of train control". comprising:

a track dividedinto insulated blocks means 7 controlledby the presence of a train in a block to supply current to the rails of a block, train controlling means, meansonthe train for short-circuiting the wheels' iand axles thereof normally held inoperative by current from said rails and operating upon the failure of the supply of current to ac-V v tuate the train controlling'means, and means in the block next in advance for preventing thesupply of current to the rails ofthe trainoccupied block.

:7. .A system of train control comprising a track divided into insulated 'hl'ocks,-a cir cuitincluding the railsofa block, a=traclr relay in said circuit affected byf the presence, of a train in thevblock, asecond circuitqin cluding the rails of the block, a brealrin" Said second circuit adapted to be closed by i the track relay upon the entrance of a tr ain into the block to supplycurrenttothe rails having a different characteristic than that of the firstTnamed circuit, and means onthe train unaffected by current in the first;

named circuit but responsive to the influence of the last-named current to control the tram. v

8. A system of train control comprising a track divided into insulated blocks, acircuit including the rails of a. block, I a track" 'relayin saidcircuitafiected by thegpresence of-a train in theqjblock, a second circuitJin-M cludingthe "rails ,of the block, a vbreakinsaid second circuit adapted to be closed by" the track relay. upon the entrance of a train intothe block to supplycurrentfto the" rails having a 7 different characteristic. than that of the firstrname'd circuit,;and Ineansf'on the train in bridging engagement-with the rails t iingthe" last-named current t trol the train. 1 V

9. A system oftrain-control comprising:

a track divided-into insulated blockspa cir-' cuit including theirails of a bloclgca track; relayc injsaid circuitiafieeted by the"; presence p of a train:in the'bloclryasecond circuit in cluding the rails ofthe block, a breaktin 7 said secondcircuit adapted tobe closed by the trackrelay upon the entrance of -a train into the block tosupply currentto the rails having. a different characteristic than :that of the first-named circuit, a second break in said secondficircuit adapted to be. controlled by .a track relay in the block in advance,

and means on the train for utilizing the current ofthe second-named circuit control thetrain.

10. 'A system of train control'comprising:

a track divided into insulated blocks, an;

alternating current track circuit including the rails of .each block, a traclr relayjinsaid circuit affected by the presence of a train the block, a direct current circuit including the rails of the block, a break inthe direct current circuit adapted to be closed bythe track relayupontheentrance of a train into the block to supply current to the rails thereof, and means on thetrain for utilizing the direct current in said rails to control the train. 7

train into the block to supply current to the rails thereof, a second break in said 11. A ystem of train control comprising:

direct current circuit adapted [to be controlled by a track relay in the bloclr'in ad Vance, and means onthe train forutilizing the direct current in said rails to control the train. p t i 7 12. A system of train control comprising: atrack divided intoinsulated blocks; means .controlled'by the presence of atrain in a block tosupply current to the railsvof theblock and to prevent the supply of current toihthe adjoining blocks upon the entrance of a trainthereto, train controlling means, and

train-carried means normally held inoperative by the influence of'current from said rails and operating upon the failure of the supply of current touactuate the train controlling-means to preventthe entrance of two trains into the sameblock.

, [13, A system oi'train control'coniprising:

'a track, divided into insulated blocks, .a train,

means, forsupplying current tothe rails of a block in advance of a train passing through said block in either direction, means on the train forutilizing current from said rails to 'controlvthe trainand operat ngv to stop the trainupon the failure of the supply of current to the rails in advance ofthetrain, and

low"

means controlled frcm the twoadjoining blocks for cutting cfi'the supply of current to the adjacent endsof the intervening block upon the-entrance or trains-into said. blocks, Whereby a train in the intervening block will be stopped upon the entrance oi a train into I the block which 'thetrain 1n the mtervemng block is approaching.

14. Asystem of train control comprising:

a track divided into insulated blocks, means in advance oi a train passing through said block in either direction, a train, means. on

; the train. for utilizing current from said for supplying current to the rails cf a block rails to control thetrain and operating to stop the trainupon the failure or the suppiy of current to the rails inzadvance or the train,

and meanscontrolled from. the ;block in advance forcutting ofi the-supply ofcurrent to a given block upon the entrance of a train into the advance block, whereby when two trains are approacl each other both trains will be stopped when either train enters the last intervening block.

15. A system oi train control comprising: a track divided into insulated bloclzs, means for supplying current to both ends of the rails of a block, a train, means on 16. A system of train control con'iprising: a track divided into in ted blocks, a normally closed track circ eluding rail: of each bloclr, a tracl; relay for each l)lOC:i\ normally energized by current in said track circuit, a normally open train co 'ol circuit including the rails of each bloc: and adapted to supply current having a dill'erent characteristic than that in the normally closed circuit, and a train carried controlling device responsive to the influence of the current supplied to the rails by the train control circuit,

- said train control circuit bein controlled jointly by the relay in a given block and the relay in the block next in advance for supplying current to the rails of the given block to control the passage of a train therethrough.

17 A system of train control comprising: a track divided into insulated blocks, a, nor mally closed tracl: circuit including the rails oi each bloclr, a track relay for each block normally energized by current in said track circuit, a normally open train control circuit including the rails or each block and adapted to supply current having a diil'erent characteristic than that in the norn'ially closed circuit, a train-carried controlling device responsive to the influence or" the current supplied to the rails by the train control circuit, a break in said control circuit adapted to be closed when the relay in the same block is deenergized, and a break in said control circuit adapted to bx, closed when the relay ol' the block in advance is energized whereby current will be supplied to control a train passing through a given block when the blocl: in advance is unoccupied. I

18. A system of train control comprising: a track divided into insulated blocks, :1 normally closed track circuit including the rails of each block, a track relay at each end of each block normally energized by current in said track circuit, normally open train control circuits connected to the rails at each end of each block, and adapted to supply current having a difierent characteristic than tiat supplied by the normally closed circuit, and a train-carried controlling device responsive to the influence of the current supplied by the train control circuits, each of said train control circuits being controlled jointly by a relay of the same block and a relay of an adjoining block for supplying current to the rails of a given block to control the passage of a train therethrough.

19. A system of train control con'iprising: a track divided into insulated blocks, it normally closed track circuit including the rails of each block, a track relay at each eno of each block normally energized by current in said track circuit, normally open train control circuits connected to the rails at each end of each block and adapted to supply current having a different characteristic than that supplied by the normally closed circuit, and a train-carried controlling device responsive to the influence of the current supplied to the rails by the train control circuits, each of said control circuits having a break adapted to be closed by the relay in the same block when deenergiZe-d, each of said control circuits also having a break adapted to be closed by a relay in an adjoining block to supply current to control the passage o1 a train through a given block.

20. A train control system including: traflic rails arranged in blocks, two trackway sources of current for each block, each of said sources bridged across the trallic rails of a block, one of said sources to supply train governing current of a given character to the traiiic rails of a block in series but normally disconnected from said rails, and the other of: said sources to supply a control current, of a character different from that of the train governing current, to the tratfic rails of a block in series, circuit means responsive to the control current to control the train governing current of another block and to connect the source of train governing current to the traffic rails of a block by the entry and traverse of a train in said block, a train, and automatic means on the train substantially continuously responsive to the influence of the train governing current flowing in the trailic rails of the block being traversed by the train but unresponsive to the control current flowing in said rails.

21. A system of train control comprising: a track divided into insulated blocks, means controlled by the presence of a train in a blo'ckto supply current to the rails of the block, means on the train responsive to the influence of the current in the rails to thereby control the train, and means in both the adjoining blocks for controlling the supply of current'to the rails of the train-occupied block;

circuit adapted to ,be closedlb-y the track relay upon the entrance of a train into the block to supply current to the rails having a difierent characteristic than that of thefirstnamed circuit, a second breakin said second circuit adapted to be controlled by 'a track relay in the block in advance, and means on the train responsive to the current of the secend-named tram. V

23. A system of train control coniprislngz circuit to thereby control the a track dividedinto insulated blocks, an alternating current track circuit including the V rails of each block, a track relay in said cirp c r V it fl t d'b th presence f a t i in th rails 1n advance ofjthe train, and means controlled from the two adjoinlng blocks forblock a direct current including the rails of V the block, a break in the direct current circuit" adapted to be closed by the trackrelay upon the entrance of a train into the block to sup ply current to'the rails thereof a'nd means on the train responsive to theo infl uence'of the direct current in said rails totherebycontrol the train. a V V 2a. A system of train control comprising': a track divided into insulated blocks, an alternating current-track circuit including the rails of each block, track relay in said circuit afiected by the presence of a train in the blocks, a direct current circuit including the rails of the block, abreak in the direct current circuit adapted to be closed by the track relay upon the entrance of a train into the block to supply current to the rails thereof, a'second break in-qsaid direct current circuit adapted to be controlled by a track relay in the block in advance; and

means on the train responsive to the influence of the, direct cur-rentin saidrails to thereby control the train. Y a a 25. A system oftrain controlcomp'rising: a track divided into insulated blocks, a train,

in advanceofa train passing through said block 1n either direct-1011, a train, means on the train responsivefto the influence of current in said rails and operating to control the train on the failure of the supply of current to the rails in advance of the train, and ineans controlled from the block in advance for cutting oil the supply of current to a given block upon the entrance of a train into the advance block, whereby when two trains are approachir each other both trains will be controlled r en eithertrain enters t-l e last intervening block.

2?. A system of train control comprising: 7

track divided into insulated blocks, means v for supplying current to both ends of the rails of a block, a tram, means on the train responsive to the influence of current in said rails and operating togcontrol the train on the failure of the supply of currentto the the entrance of trains into said blocks, whereby when two trains are running in the same direction'the following train Will'be con trolled upon entering the last intervening' block While the train in advance Will be unaffected T Signed at New York, in the county of New York and State of New York this 26th dayvof April, A. D. 1916. YVILLIAM VVQ MACFARLANE 7 means for supplying current to the rails of train into the block which the train in a block inadvanceof a train passingthrough said block in either direction, means on the train resp'onsiveto the influence of current in said rails and operating to control the train on the failure of the supply of current to the rails in advance of the train, and means controlled from the two adjoining blocks for cutting ofi the supply of current to the adjacent ends of theintervening block upon the entrance of trains into said blocks, whereby a train in the intervening block \villbe controlledupon the entrance of a the intervening block is approaching.

26. A system'of train control comprising: a track divided into insulated blocks, means for supplying current to the rails of a block

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