US1794545A - Continuous inductive train-control system - Google Patents

Description

'March 3, 1931. w. H. 'REICHARD CONTINUOUS INDUQTIVE TRAIN CONTROL SYSTEM Filed Nov. 30 1925 w 2 6210: TOR.

A TORNEY Q .4 n TF 2 N/ .w. .N .V kw 30.2.: 0% EOt Lm v oL+cou 330cm mmmuxm ro cou F E :0 L 1 mm a wwmn 1 Patented Mar; 1931 1, N TED STATES ADE 1r. LREIOHARD, or ROCHESTER, NEWYOBK, ASSIG'NOR T GENERAL RAILWAY SIGNAL COMPANY, or ROCHESTER, NEWYOYRK,

' 5 operation of the car-carried receiving ap-' control when these currents are cut off and PATENT OFFICE .COiNTINUOUS INDUCTIVE TRAINCONTROL SYSTEM Application filed November 1 This invention relates to automatic train control and-more sparticularly concerns a .train controlsystem of the continuous induc tive type embodying means for checking the paratus. v i In an automatic train control system of the well known continuous inductive type,

control currents flow in the track rails under favorable traffic conditions only, these con trol currents serving to transmit influences to car-earned recelving and control equip- 'ment whlch is adapted to inltratea restrlctive no influences are transmitted. One modified system of continuous inductive train control contemplates the use of a-so-called acknowl edging means which permits a train to proceed under unfavorable traflic conditions, that is, over sections of trackway or blocks in which no control currents are flowing, without automatic restriction, provided a suitable manual acknowledgingact is performed as the train enters each-block in which unfavorable traffic conditions exist, the acknowledging act at the entrance to a block in which unfavorable traflicconditions exist serving to temporarily place the car-carried apparatus in an inactive condition; In such a system, the control apparatus on the vehicle is again placed in its'active, condition by the transmission of amomentary impulse from the-trackway .at a point near the entrance end .of each track block, under un favorable, as wellas favorable, traffic conditions, unless-the said manual acknowledging act is repeated at this point.

Since the failure of they receiving equipment while the vehicle is traversing a block in which unfavorable traffic conditions exist would prevent the transmission of the momentary impulse at the entrance to a the succeeding block under unfavorable traffic conditions, and so prevent the restoration of the car-carried apparatus to its active condition, it is very essential that the car-carried receiving equipmenton a system ofthis type shall operate properly, and that its opera- .tion, particularly while the vehicle is trav- 30, 1925. Serial No, 72,290.

.eling under unfavorable traflic conditions, be checked in some safe manner.

Asce'rtain portions ofthe trackway, such as 'sidings, branchlines and the like, are

usually not-equipped for train control op-e 'vided' forby the use of special trackway impulse-transmitting means for enabling the car-carried apparatus to berendered inactive; these means being located at the entrance to the unequipped territory, and to provide further impulse transmitting means at points where equipped-sections of trackway are again entered, for placing the car-carried 'equipmentiin its active controlling condition. As in the case of train operation under unfavorable traflicconditions, it is desirable to check theproper operation of the car-carried receiving equipment while the vehicle is traveling in the'unequipped trackway sections as the failure of this receiving equip- 'ment at such points would prevent there- .storation'of thecontrol apparatus to its active condition as the vehicle re-enters equipped or train control territory, thus permitting the vehicle to 'proceed'in train control territory without the protection of automatic control;

'With the above and other considerations in mind it is proposed in accordance with the present invention toprovide a train control apparatus may beplaced in the inactive condition for vehicle travelunder unfavorable traffic conditions in equipped sections of jtrackway and ,for vehicle travel in unequipped sections of trackway, and in which means are provided for checkingthe oper ation of the car-carried receiving equipment while in its inactive condition.

cifically, itis proposed to provide an auto- :matic train control system of the continuous inductive type in which the car-carried restrictive controlling apparatus may be rendered inactive for vehicle travel in successive track blocks under unfavorable traffic condi- More spesystem in which the car-carried controlling V ceiving equipment from a car-carried source tions, and for vehicle travel in unequipped lays energized in accordance with traific contrackway sections, by the cooperation of a ,ditions in advance. In the block H, this coninanual act on the part of the engineer and trol of the train control current is effected by the transmission of an influence from the the track relay 3 of the block I, while in the trackway, and in which the proper operation block I the train control current is controlled of the vehicle receiving equipment is checked through the contact fingers 8 and 9 of the line while the restrictive control apparatus is inrelay 10, the energization of this relay 10 active by means of the energization of. the re-. being. controlled in accordance with traffic conditions as hereinafter describedof energyv Wayside signals of the color light, sema- Other specific objects, advantages and phor-e or other suitable type are preferably characteristic features of the present invenused in connection with the system of the tion will become apparent as the description present invention, and for the purpose of thereof progresses. v illustration, semaphore signals Z have been In describing the invention in detail, refershown in the entrance end of each block in a ence will be made to the accompanyingdraw- C nventi nal manner only, a showing of the 1ng in which the trackway and car-carried p rating devlccs and CI'I'CHltS for these sigapparatus of a continuous inductive train 11211 belng omltted, as-this equipment is well control system embodying the'present invenkIlOWIl t0. those Skilled in t e rt and for s tion has been shown in a diagrammatic and 110 P Of the P e t i fifi di l g Inthe system shown, an acknowledging Th nt i ti i li bl t many loo-p 1s usedat the exit end of each block, the forms of continuous inductive train control 0p in block prising the Wires 11, Systems, b t i Order t i lif th disclolocated adjacent the track rails for a short sure, the invention has been shown in connec- $605011 0f t ay and ending at the exit tion with a t ieal t i t ol y te f th end of the block. Each loop is continuously continuous inductive three-position type. s pp With alternating Current 0f twill As this type of train control system is in OODtYOl r q n y, by means of a transeneral well known to those skilled inthe' fol'mel'isuch block Connected to art,bits construction will be onlybriefiy de-; The transmissionreline The P 'scri ed.

. winding of transformer 14 in block 'H, Referring to the trackway apparatus h included in series with the acknowledgtracl; railsl have been shown divided-into g 1 0p aS-ShOWn. This transformer blocks and sections by the insulating joints 2, v s 0 upply train control current to the and the block I and a portion of the block H t k rails through'the contact fingers 6 and in train control territory, the excess energy 7 of the track relay 3 and a circuit which is section J and a portion of the block K in nonvi from the drawings. This connectrain control territory have been shown. As tion of the trackway acknowledging loops the various devices and circuits in the several 11 to the source of supply of the train conlocks n train control territory are substan trol current delivered to the track rails acts m n d m l, th a a t 11 b 1 as a check on the energization of the acknowl- 1 scribed in connection with one block only, the edging loops, a break or de-energization of 1 V 00 11 espondmg elements in the adjacent the acknowledging loops causing the failure track rails at the entrance end of each block,

blocks being referred to by like reference of supply of current to the'track rails and so characters having distinctive exponents. For 1 instituting danger trafiic conditions. GYQ theletters and have e A short insulated section of track rails, 2 3111 1 1 Z g1 g glac PP termed the excess energy section, is provided 1 u 3 -t 6 if; a f bl 5011169. 0 ll'ect C111 at a point along the trackway where unren i P em 3 a Storage equipped or non-train control territorv is Referr1n l' to the trackway apparatus the d Aj usual tr ck rel vs 3 re connected across "the entele "minim-1mg tram Control current 1 u Cu, 'LL i v 1s supplled to the track rails of this scctlon these relays being of the direct current yp through the transformer 1.6 as clearly shown,

in the embodiment shown, and being supplied magmtude of this Current beino' appl'eci' with current under favorable traflic condil greater than t-hat sllpphed to the track tions from the track battery 47 connected rails of the blocks in train control territory.

. across the track mils at the exit end of each In order that the train control and signaling block.

A t 'ti g. train control Current is trackway apparatus in the block I may resupplied to the two track rails of each block fleet tl'alfic Conditions in afll'ancei Pu track in series through the transformer 5 whose secrelay of the alternating current @1 is ondary i di i connected across th t k connected across the rails at the entrance end railsiat the exit end of the block in series with: 0f the SQCtiOII J, and the line relay 10 conthe track batteries 4 as clearly shown; The trolling the train control current in the block application of the train control current to the "I is energized througha front contact of this track rails is controlled by the contacts of rerelay, and of the track relay 18 associated with the first block K in non-train control territory.

It isapparent from the description given and'the disclosure in thedrawings that when train is located in a given block, track cir cuit current is shunted from the track rails Referringnow, more particularly, to the car-carried apparatus, a railway vehicle has been conventionallyrepresented in the block I-I'by the wheels and axles 19, the normal di- "rection of traffic being indicated by the arrow. This vehicle is providedwith suitable inductive receiving coils 20' and 21, which may or may not be provided with laminated iron cores. The coils 20 and 21 are meunted in inductive relation to the track rails ahead oftheleading axles of the vehicle, and are so connected that voltages induced therein'by control currents flowing 1n opposite direc-' tions in thetwo track rails will be additive.

Thereceivin'g coils 20 and 21 are'connected' to the input circuit of a suitable amplifier A,

this input circuit including the resistance units 'QQ/an'd 23 asclearly shown in the drawings. The output circuit of the amplifier A is connected tothe'two windings 24 and 25 of a polyphase main car relay MR. This relay MR is of the type now common in train control practice and is provided with su table movable contact fingers '26, 27, 28 and-29 which act to open "and close suitable control circuits under diflerent 'control'conditions as hereinafter descr bed.

The CtlY-CEtTIlQCl apparatus also includes arepeater relay KB. This relay is of the well known directcurrent type and is pro videdwithtwo separate windings, 30 and 31. The windinga30 1s arranged-to be energized from a' car-carried source of energy through the manually operable push buttoii NB, the circuit' for this energization of the 001i 30 being :obvious from the drawings,- An acknowledging relay Asia is also provided on the vehicle, this relay being of the direct A non-control current "two winding type. relay N0 of the usual direct current type is also provided on the vehicleto maintain the vehicle carried'control apparatus in its in active condition when energized as hereinafter described. 1

A manually opcrablecontactor AC is pro-.. vid'ed, having a normallyopen contact32' and a normally closed contact 33. The contact 33is provided with a retarding'mech anism of any suitable type which acts to prevent the opening of the circuit through thecontact '33 until after the acknowledging contactor AC has been'depressed "for a predetermined interval of time. In the diagrammatic form ofcontactor' shown, the retarding means has been illustrated as a simple dash pot and flexible contact arrangement, designated as a'whole as'DP, it being understood that any other suitable timing apparatus might be used to accomplish this result; The acknowledging cont-actor AC is preferably locatedwithin easy access of the engineer. A second manually operable contactor RC is'provided on the vehicle,'having two movable contact fingers 34 and 35. This "contactor' is preferably located at some point on 'thevehicle which isnot accessible while the train is in" motion. Y

The vehicle brakes :may-be controlled in any suitable manner, by'ineans of any one of a number of well known devices adapted for this purpose. vAs the initiation of an automatic brake application is usually accomplished by means of the -deenergizati'on of some suitable electro-magnetic device, an 6lCl3I'O.])I18LI1 ll&t1C valve EPV has been 11- lustr-ated, it being assumed that this valve acts when de-energizedtoiinpose an automatic' brake application whichpersists until the vehicle has been brought substantially to a stop or until the vehicle speed has been reduced to a safe low limit. The-electropneumatiovalve EPV is provided with a movable contact element36 which-engages two stationary contacts 37'and 38 when the valve EPV is energized as shown, the purpose of these contacts be ng hereinafter explained. q

One featureof the present invention comprises theprovision of means for checking the operation of the car-carried receiving apparatus when no influences are being received from the-trackway. Thischecking operation is accomplished by providing a car-carried source of energy which acts to supply control influences to the receiving c'oils 20 and 21 and so to energize the entire car car'ried receiving circuits. This car-carried source of energy may take any suitable form of alternating current source, and in the embodiment shown, avibratory generator or buzzer HD has been used, this buzzer comprisingfa primary coil 39, avibratory armature'lO and a secondary or output coil 412-, The secondary coil' ll of the buzzer "HD is connected through an obvious circuit to the coils42 and 43, these coils being mounted" in inductive relation to the receiving coils 21 and20, respectively.

Operatiom All of the circuits and devices in the drawings have been shown in their normal operating conditiom that is, with a train proceeding under favorabletraflic con ditions in train control territory,;.and with allfci'rcuits and devices properly energized.

" Considering first the operation of the system embodying the present invention under clear traffic conditions in'a section o'ftrackway which is equipped for automatic train ,control operation, assume that the train under conslderation 1s proceedlng 1n the block H w1th no traln, broken rail or other hazard affooting the flow of control current in the track rails of the block I, the section J or the block K in advance. Under these conditions, train control current flows in the track rails of the block H, and induces voltages in the receiving coils and 21, and these voltages are amplified by the amplifier A and serveto energize the main relay ME. I should be understood that suitable condensersand reactances, in-

cluded Within the wholly conventionally shown amplifier A, are provided in the varilousinput and output circuits of this amplifier A, and tune the input circuits to resonance at the train control frequency, and provide a proper phase displacement between the alternating currents in the output circuits to operate'the main relay MB. The main relay MB is energized in its normal direction as shown, and a circuit is completed for energizing the electro-pneuinatic valve EPV, which circuit may be traced as follows: from batteryterminal B, contact finger 26 and stationary contact for the main relay MR, wires 44, and 63,

contact finger 33 and back contact of the acknowledging contactor AC, wire i5, contact finger 35 and back contact of the reset contactor RC, wires 46 and i'Z-and the winding of the electro-pneumatic valve EPV to the control current to be cut off from the track rails of the block I and placing the wayside signal at the entrance end of this block in its caution position. If the engineer is alert and properly observes and recogmzes the caution indication of this wayside signal at the entrance end of the block I, he depresses the acknowledging contactor AC just before the vehicle enters this caution block, and thus closes a pick up circuit for the acknowledging relay A070, which circuit maybe traced as follows: fron'ithe battery terminal B, contact finger 32 and front contact of the acknowledging contactor AC, wire 48, stationary contact 37, movable contact 36- and stationary contac't38 of the electro-pneumatic valve EPV, wiresA-9 and and the winding 51 of the acknowledging relay A076 to the battery terminal C. The energization of the 1a'c knowledging relay A070 closes an energizing V circuit for the vibrator or buzzer Hi), this circuit being traceable as follows: from the battery terminal B, front contactand contact fin er 52 of the acknowledging relay A070,

wire 53, contact element 5& of the buzzer HI), Vibratory armature 40 of the buzzer and the coil 39 to the battery terminal C. The energization of the buzzer HD causes an alternating current of train control frequency to flow through the coils 42 and 43 of the car-carried receiving elements, in such a direction (in the present case the same in both coils) as to cause the voltages induced in the car-carried receiving coils 20 and 21 to be of such phase relation as to result in the energization of the main relay ME in the reverse direction. With the main relay MR energized reversely, a stick circuit for the acknowledging relay jack is completed which circuit may be traced follows: from the battery terminal B, conlinger 29 and stationary contact 55 of main relay MR, wire 56, contact linger 57 and front contact of the acknowledging relay $1070, wire 58 and winding 60 of the acknowledging relay A070 to the battery terminal U. The energization of the acknowledging relay Ac]; also serves to complete an alternative energizing circuit for the electro-pneumatic valve EPV, which circuit is traceable as follows: from the battery terminal B, contact finger 61 and front contact of the acknowledging relay Acic, wires 62 and 68, Contact finger 33 and front contact of the acknowledging contactor AC, wire 45, contact finger tact the 35 and front contact of the reset contactor end of the caution block, tratfic conditions in advance are unfavorable, that is, the next succeeding block is a cautlon or a danger block,

the engineer is again required to operate the acknowledging contactor AC to prevent an automatic brake application at this point. As the vehicle approaches the exit end of a block under unfavorable traffic conditions, the receiving coils 20 and 21 encounter the acknowledging loop 11, and the voltages induced in the coils 20 and 21 by the current flowing in this acknowledging loop are enough to more than neutralize the efiect of the auxiliary coils 4:2 and 43, to momentarily energize the main relay ME in the normal direction. VVhenever the main relay MR is momentarily energized normal, the stick circuit for the acknowledging relay A070, traced above," is broken. If the engineeris alert, however, and has recognized the unfavorable signal indication and depresses the acknowledging contactorrlC in recognition thereof, when first reachiru a loop 11, and has so maintained it until the loop is passed, the acknowledging relay A07; is maintained energized by the encaution, block, the main relay MB is again.

energized in its reverse direction by means of the energy supplied from the buzzer HD, the stick circuitfor the acknowledging relay A070 is again closed and the train may proceed in the caution or danger block without automatic restriction. 7 If the engineer is incapacitated, asleep 0 for any otherreason fails to recognize and ac knowledge an unfavorable signal indication at the entrance to-a caution block, the main relay MB is ole-energized after the caution block is entered. The de-energization of the main relay causes the energizing circuit for the electro-pneumatic valve EPV through the contact finger 26 to be broken, this circuit having been traced above, and an automatic brake application results, bringing the train to a stop or'imposing a low speed restriction. It shouldbe noted that the engineer may not avoid an automatic application by depressing the acknowledging contactor AC after the electro-pneumatic valve EPV has been de-energized, since the movable contact36 of the valve EPV disengages its stationary contacts when the valve is de-energized and thus breaks the pick up circuit for the acknowledging relay Ac/b.

Afterthe electro-pneumatic valve EPV has been de-energized, as a result of the failure on the part of the engineer to properly acknowledge an unfavorable signal indication, the vehicle may be released from such automatic restriction only after it has been brought to a stop. The engineer disinounts and depresses the reset contactor RC, which is located in such a position as to be accessible only from the ground, thus completing a pick-up circuit for the acknowledging relay A070, which circuit may be traced as follows: from the battery terminal B, contact finger 29 and stationary contact 65 of the main relay MR, wire 66, contact finger 34 and back contact of the resetcontactor RC, wires67 and 50, and the winding 51 of the acknowledging relay to the battery terminal C. The energization of the acknowledging relay A070 causes the energization of the buzzer HD which supplies energy to the receiving circuits and energizes the main relay MB in its reverse direction,

thus completing a stick circuit for the acknowledgment relay, including the contact finger 29 and stationary contact 55 of the main relay MR, all as described above. The

vehicle may now proceed in the caution or danger block without automatic restriction, RC having been restored to its normal position.

If the engineer fails to acknowledge when passing successive danger or caution signals,

the main relay MB- is energized in its normal direction by the acknowledging loop 11 at the exit end of the block as described above, and the stick circuit for theacknowledging relay A070 is broken, this circuit having been traced.

The acknowledging relay A070 being de-ener-' gized, the electro-pneumatic valve EPV is deenergized as the next caution or danger block is entered, as the main relay 1 R is de-energized due to lackof control currents in the track rails. The buzzer HD is, of course,.deenergized when the acknowledging relay A071: is de-energized. j i 1 lnorder that the engineer may not avoid an automatic brake application by manipuia-.

tion of the manually operable contactors, the acknowledging contactor AC and the reset contactor R0 are protected against misuse by means of suitable protection contacts. If the acknowledging contactor AC is secured in the depressed position in an attempt to avoid an automatic restriction, the contact linger 33 thereof'disengages its front contact aft-er a predetermined time interval, as eX- plained above, and the energizing circuit for the electric-pneumatic valve, EPV, is broken at this point, causing an automatic brake application to be imposed. In a like manner, after the reset contactor RC is secured in its depressed position, its contact finger35 disen ges the frontcontact and breaks the energizing circuit to the valve,EPV, this energizing circuit through these contacts having been traced above.

It is seen from the description given that in order to avoid an automatic brake application, the engineer is forced to acknowledge each caution and danger signal. It is also seen that this acknowledging act on the part of the engineer niustbe performed before the block in which unfavorable trafiic conditions exist is enterechand that the acknowledgement must be repeated at the entrance tosuccessiveblocks in which unfavorabletraiiic conditions exist.

Considering now the operation of the systemin checking the receivingapparatus, assumethatthe vehicle under consideration has passed a caution signal, properly acknowlcausing the .de energization of this acknowle edging relay. The retraction of the contact finger 52 of the acknowledging relay A0711 causes the de-energization of the buzzer HD.

The retraction of the contact finger 61 of the acknowledging-relaycauses the de-energization of the electro-pneumatic' valve EPV,

and an automatic brake application results, bringing the vehicle to a stop or substantially reducing its speed. application, occurring unexpectedly under unfavorable traiiic conditions, apprises the engineer of' the fact that the car-carried receiving apparatus is in some manner defective, and he then inspects, and if necessary, repairs, such receiving equipn'ient before proceeding. Once the receiving apparatus has been properly repaired, the acknowledging relay A070 may be re-energized by the operation of the reset contactor RC as described above, and the train may again proceed under unfavorable trafiic conditions without restriction.

Considering now the operation of the system over sections of trackway which are unequipped for automatic train control, assume that the vehicle under consideration enters the excess energy section J from the block I, this being assumed to be the last blockin an equipped section of traclzway; the engineer is apprised of the fact that he is about to enter unequipped territory by means of his knowledge of the route or by means of some suitable wayside indication, and as the vehicie enters the excess energ section J he depresses the non-control push iutton NB, energizing the repeater relay RR through a circuit which is obvious from the drawings. The energizetion of the repeater relay RR causes its con tact fingers 68 and 68a to be attracted, disengaging their back contacts and so opening normally closed shunt circuits around the resistance units 22 and .18 in the input circuit to the amplifier A, these shunt circuits being clearly shown in the drawings. The repeater relay RR is maintained energizedthrough a stick circuit including the contact finger 2? of the main relay MR and the contact linger 69 of the relay RR, this circuit being obvious from the drawin and for this reason the engineer need not maintain the push button NB depressed during all the time the vehicle is passing through the excess energy section J. As the control current flowing in the section J is of a far greater magnitude than that flowing in the track rails of the usual track blocks in equipped territory the insertion of the resistance units 22 and 23 in the receiving circuits does not affect the operation of the main relay MR, which relay remains energized in its normal direction as the excess energy section J is traversed. Under these conditions, a pick up circuit for the non-control relay NC is completed, which circuit may be traced follows: from the battery terminal B, contact finger 28 and stationary contact 70, of the main relay MR, wire 71, contact finger 72 and front contact of the repeater relay RR, wires 73 and 7a, and the winding of the non-control relay NC to the battery terminal C. The energization of the non-control relay NC causes its contact finger This automatic brake 7 5'to engage its front contact, thus completing an obvlous energizing circuit for the buzzer HD, and supplying alternatmg current of train control frequency inductively to the receiving coils 20 and 21. As the vehicle enters the first block K in non-train control versely, astick circuit for the non-control relay NC is completed, which circuit may be traced as follows: from the battery termlnal B, contact finger 28, and stationary contact 76 of the main relay MR, wire 77, front contact and contact finger 78 of the non-control relay NC, wires 79 and 74, and the winding of the non-control relay NC to the battery terminal C. lVit-h the non-control relay NC energized, its contact finger 80 engages its front contact and a circuit for energizing the eiectro-pneumatic valve EPV is completed which circuit may be traced as follows: from the battery terminal B, contact finger 80 and front contact of the non-control relay NC, wires 81 and 47 and the winding of the electro-pneumatic valve EPC to the battery terminal C. As the train under consideration proceeds in the unequipped trackway, the receiving coils 20 and 21 are supplied with alternating current of train control frequency from the car-carried buzzer HD, the

inactive condition and permitting the train to proceed wlthout restriction in the unequipped territory. 7

The normal control current flowing in the equipped blocks is of a magnitude sufiicient to overcome the effect of HD and operate relay MR to normal position. Thus, when the train under consideration leaves the un equipped territory and again enters a section of trackway which is equipped for train control operation, the control currents flowing in the track rails of the first equipped block or, in case unfavorable traific conditions exist in this block,'in the acknowledging loop 11 at the exitend of this block, acts to neutralize the currents induced in the receiving coils 20 and 21 by the car-carried buzzer HD and to energize the main relay MB in its normal direction. The stick circuit for the non-control relay NC is'broken when the main relay leaves its reverse energized position, the buzzer HD isde-energized and-the alternative energized circuit for (the electro-pneumatic valve EPV,

is broken at the contact finger of the noncontrol relay NC. The electro-pneuinatic valve EPV is,however, energized through the contact finger 26 of the main relay MR, and the train may now proceed in the equipped territory under the protection of the matic control as described above.

If the receiving equipment should fail to operate while the. train under consideration circuit for the buzzer HD is also interrupted .l train.

When the buzzer H1) is de-energized, the circuit through the secondary coil 41 thereof, and the coils 42 and 43 on the receivers, forms a closed or short-circuited secondary circuit, inductively associated with the receiving coils 20 and 21. This secondary circuit might, with some designs of receivers, act to oppose or choke the normal flux resulting from the control currents in the track rails, from the ;-coils 20and 2-1. This choking action would prevent the normal operation of the train control system, as it would produce the effect of dangerous traiiic conditions in, the carfrequency linking the coils l2 and 43.

carried apparatus at all times. This undesirable choking effect may be reduced to a negligible amount by so arranging the constants of the circuit including thecoil 41, that very little voltage is'generated in this circuit as a result of an alternating fluxof train contrfi necessary, the circuit through the coil 41 may be opened when the buzzer HD is de-energized, this being conveniently accomplished by including the front contacts of the noncontrol relay NC, and of the acknowledging. relay A6711, in parallel in the circuit through the coil 41. 1

As described above, the energizing circuit for applying the train control current to the auto the cludes a circuit through the corresponding acknowledging loop 11. For this reason any failure or de-energization of the acknowledging loops will cause the train control current to be out off from the track rails of the block in which the defective acknowledging loop is located. In this manner the energizationof acknowledgingloops is before the defective loop is encountered.

Fromthe foregoing description 1t 1s evldent that an automatic train controlsystem has been produced in which acknowledgmentof all unfavorable traflic conditions is required, in which means is provided for train operationin unequipped trackway sections, and in which :theproper operation of the carcarried receiving equipment is constantly and continuously checked when no influences are being received from the trackway in unequipped or equipped trackway sections. The present invention has been disclosed in connection-with a rather specific system of automatic train control, and for this reason it should be understood that many changes,

modifications and additions to this system might be made without departing from the spirit of the invention as defined by the appended claims.

Vllhat is desired to be secured by Letters Patent of the United States is 1. Inanautomatic train control system, trackway means for transmitting influences to a moving vehicleunder favorable tratlic conditions only, a car-carried receiving circuit for receiving saidinfiuences, car-carried means for initiating a brake application when no such influences are transmitted, and apparatus for preventing said brake application provided a manualacknowledg-ing act is performed before the cessation of said influences, said apparatus including a vehicle carried source for supplying influences to said receiving circuit.

2. In an automatic train control system, trackway mean-sfor transmitting influences to a vehiclegcarried receiving circuit under favorable, traff c conditions only, car-carried means for initiating an automatic brake application when no such influences are transmitted, means for supplyingsaid receiving circuit with influences from a vehicle carried source under unfavorable trafiic conditions provided a manualacknowledging act is performed before the cessation of said influences from the trac'k'way, and trackway means at spaced points, for causing said influences. from said vehicle carried source to be cut off unless said manual acknowledging act is repeated at said spaced points.

8. In an automatic train control system, trackway means for continuously transmit-- ting influences to a moving vehicle under favorable traffic conditions only, car-carried constantly I I checked,and a failure of this energization re sults in the automatic restriction of a train electro-responsive means normally energized by said influences and adapted to initiate an. automatic brake application when de-energized, a vehicle carried device, acting when energized to supply influences to said electroresponsive means and thereby prevent an automatic brake application, and manually actuable means eliective to. ener ize said de-- ,tive to cause the energization of said influence generating device actuated while said brake applying device is energized.

5. In an automatic train control system, trackway means for continuously transn'iit- .ting influences to a moving vehicle under favorable traihc conditions only, a receiving circuit on the vehicle for receiving said 111-- fluences, a car-carried main relay energized by said influences through said receiving circuit, a normally energized brake applying device adapted to initiate an automatic brake application when (ls-energized and maintained energized by the energization of said main relay, and means for maintaining said main relay and said brake applying device energized while the vehicle is proceedlng under unfavorable trailic conditions comprising, a vehicle carried influence generating device, acting when energized to supply influences to said receiving circuit, a stick relay for energizing said generating device when said stick relay is energized and an energizing circuit for said stick relay in: cluding a manually operable contactor and i contacts closed only when said brake applying device is energized.

6. In an automatic train control'system', trackway means for continuously transmitting influences to a moving vehicle under fav- T orable traffic conditions only, a receiving circuit on the vehicle for receiving said influences, a car-carried three-position relay energized to assume its normal position by said influences through said receiving circuit. a normally energized brake applying device, adapted to initiate an automatic brake application, and de-energized and maintained energized by the normal energization of said three-position relay, and means for preventing an automatic brake application upon the cessation of said trackway influences, comprising, a car-carried influence generating device adapted when energized to supply influences to said receiving circuit and to energize said three-position relay to assume its reverse energized position, a stick relay adapted when energized to energize said influence generating device and said brake applying device, a pick-up circuit for said stick relay including a manually operable contactor and contacts closed only when said brake applying device is energized and a stick circuit for said stick relay including a contact of said three-position relay closed only when said relay is energized to assume its reverse position.

7. In an automatic train control system, trackway means for continuously transmitting influences to a moving vehicle under favorable traflic conditions only, a car-carried main relay energized by said influences, a brake applying device adapted to initiate an automatic brake application when active, and maintained inactive by the energization of said main relay by said trackway means, a car-carried influence generating device adapted when energized to supply influences to said main relay, a stick relay adapted when energized to energize said influence generating device and to maintain said brake applying device inactive, a pick-up circuit for said stick relay including a manually operable contactor and contacts closed only when said brake applying device is inactive, and a stick circuit for said stick relay including contacts of said main relay closed only when said main relay is energized from said influence generating device.

8. In an automatic train control system for railways having portions of their trackway equipped for automatic train control and portions not so equipped, trackway means in said equipped portions for continuously transmitting influences to receiving means on a moving vehicle under favorable traific conditions only, car-carried means for initiating a brake application when no such influences are transmitted, and apparatus for preventing said brake application providing a manual acknowledging act is performed before the cessation of said influences in said equipped portions of trackway, or before the vehicle enters said unequipped portions of trackway, said apparatus including a vehicle carried device for supplying influences to said receiving means.

9. In an automatic train control system for railways having portions of their trackway equipped for automatic train control and portions not so equipped, trackway means in said equipped portions for continuously transmitting influences to a moving vehicle under favorable traffic conditions only, trackway, means at the entrance to said unequipped portions for transmitting distinctive influencesto the vehicle, a car-carried main relay energized bysaid trackway influences through a receiving circuit, a nor mally energized brake applying device acting to initiate an automatic brake applica tion when 'de-energized and maintained energized when said main relay is energized by said trackway influences, a car-carried -1nfluence generating device adapted when energized to supply influences to said main relay through said receiving circuit, an acknowledging stick relay acting when energized. to energize said influence generating'device and said brake applying device, a pick-up circuit for said acknowledging relay including a manually operable contactor and contacts closed only when said brake applying device is energized, a stick circuit for said acknowledging relay closed only when said main relay is energized by. said influences from said car-carried generating, device, a non-control stick relay, acting when energized to ener gizesaid influence generating device 1 and said brake applying device, a pickup circuit for said non-control relay closed only if a manually operable contactor is operated when said trackway means at the entrance to said unequippedportions of trackway 1S encountered, and a stick circuit for said noncontrol relay closed only when said ma n relay is energized by influences from said car-carried generating device.

1O. In an automatic train control system for railway-s having portions of the r track- Way equipped for automatic train control and portions not so equipped, trackway means in said equipped portions for continuously transmitting influences to receiving means on a moving vehicle under favorablctraflic conditions only, a car-carried brake applying device adapted to initiate an automatic brake application when active, car-carried control means for maintaining said brake applying device inactive so long as said influences are received from the trackway, means including a car-carried influence generating deviceto at times aflect said receiving means for ma ntaining said brake applying device lnactive when the vehicle is'traveling under unfavorable traflic conditions in saidequipped portions of trackway, andfurther means, also including said car-carried influence generating device, for maintaining said brake applying device inactive when the vehicle is traveling in said unequippedportions of trackway. I

11. In an automatic train control system for railways having portions of their trackway equipped for automatlc train control and portions not so equipped, trackway means in said equipped portions for continuously transmitting influences to a moving vehicle under favorable traflic conditions only, trackway means at the entrance to said unequipped portions of trackway for transmitting a distinctive influence, different from the influence applying transmitted at any other portion of trackway to the=vehicle', a= car-carriedbrake' applying device 'adapted to: initiate an automatic brake application when :a'ctive, car-carried control means iior ma ntaining said brake applying device'- inactive so long-:as saidfinfluences are receivedfrom-the trackway, a car-carried miluence generating (l6V1C6,-'11lem1S including said. generating device and a manually en- ,ergizablerelayacting to maintain said brake vice inactive :when the vehicle is'travelin underunfavorable traflic condi-v tions in "equippedportion-s oi": trackway provided; sa1d-relay is manually energized before said .unfa\orahle 'tral'flc conditions are encountered, and means including said generating device and-a second-manually energizabletrelay, acting to maintain said brake app ying device inactive while the vehiclejs traveling in said i-uiequipped portionso' irackway, provided said-second manually; energizable; .relay is energized while 1shemgatransnntted said distinctive. influence tothevehicle. y .12 v 1111 an automatic tra n con. ,7

a kwayaineans,fo tran mit ie means iiorinitiatinga restriction on the car hen such .11 M me are. t ansmitt an pparatus, ,i'cluding a anca ri d ou of energy, for preventing such a restriction by e rglzingrsaid receiving ircui .3-: In enautomati train ontr y m, I

said influencesby other influences of a distinctive character from said influences, for

preventing saidrestriction in the same man ner as did said electrical influences.

15. In an automatic train control system. trackway means for transmitting influences to a receiving circuit on a moving vehicle only under favorable traflic conditions, carcarriedmeans for initiating a restriction on the car when no such influences are transmitted, and apparatus operable for substitu ing, for said influences, other influences from a car-carried'source of energy, to affect said receiving circuit, which other influences per- 1 system, g influences toia: receiving circuit-on amoving vehicle only 7 under-i o abletrafiicco ditions-,- a -ca ri so Q sist after completion of the operation ofsaid apparatus, to thus prevent said restriction.

16. In a train control system, a car-carried means including receiving means automatically responsive to trafiic conditions in train control territory, a train restricting device controlled by the responsive means to cause a train restriction, and apparatus including a car-carricd-Vsource of energy, at times applicable to said receiving means, operable to prevent a train restriction by causing an cnergization of the receiving means different from What occurs in train control territory and which persists after the completion of the operation of said apparatus.

17. In a train control system, a car-carried relay responsive in train control territory to assume difierent positions in accordance With traific conditions, a train restricting device controlled by said relay to at once cause a train restriction, a car-carried source of energy, and car-carried apparatus operable to prevent such a train restriction by energizso as to assume a position which is different from any caused bytrafiic conditions.

18. In an automatic train control system, trackway means for continuously transmitting influences to a moving vehicle under favorable traflic conditions only, car-carried electro-responsive means normally energized by said influences and adapted to initiate an automatic brake application when deenergized, a vehicle carried device, acting When energized to supply influences to said electroresponsive means and thereby prevent an automatic brake application, and manually actuable means effective to energize said device. 7 In testimony whereof I aflix my signature.

WADE H. REICH ARD.

111g said relay from said car-carried source-

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