US1794546A - Continuous inductive train-control system - Google Patents

Description

6 3, 1931. w. H. REICHARD CONTINUOUS INDUCTIVE TRAIN CONTROL SYSTEM Filed Jan. 50, 1929 3 Sheets-Sheet l l VE TQR M W, ATTORN EY March 3, 1931. w. H. REICHARD CONTINUOUS INDUCTIVE TRAIN CONTROL SYSTEM Filed Jan. 30, 1929 3 Sheets-Sheet 2 BYM M mam TQRNEY March 3, 1931. w. H REICHARD CONTINUGUS INDUCTIVE TRAIN CONTROL SYSTEM Filed Jan. 30, 1929 3 Sheets-Sheet 3 .mUdE

wwuw n 12% 3,; ATTOF'INEY i To Patented Mar. 3, 1931 ET- OFFICE wann ii; nnronnnn, or noorr'nsrhn, new YonK ssIeNon TO GENE AL RAILWAY srennn COMPANY, or nocnns'rnn, EW YORK oonrinoons rnnoorrvn 'rnnmoonrnon srs'rmvr ApplicationfiIedJ'an iary 30, 1929. seria n. 336,090.

"This invention relates to train control systems of the continuous-inductive permissive type, in which an acknowledgment is required at'each of successive stop signals,

and relates more particularly to the carcarried apparatus thereof.

In accordance with the present invention suitable brake control apparatus, in the first instance governed in accordance with current flowing in the track rails and held inactive in clear territory, is held inactive in non-clear territory by suitable car-carried means requiring, manual acknowledgment, which means is again rendered'inactive at-the end of each block of the railway system in response to energy flowing in a track loop at the end of such block. Suitable acknoWledgingmeans is provided to render the brake control means inactive when the train is travelling in non-clear territory, and suitable reset means is employed for restoring the brake control means in the event it is automatically actuated. The invention has been exemplified in three different forms, in the first of which both theacknowledging and the reset means are of the pneumatic'type, in the second form of whichboth the reset and the acknowledging means are of the electrically operated type, and in the thirdform the acknowledging means is of the electric type and the reset means is of the pneumatic type. These three forms of the invention will be briefly described after which the novel features thereof will be pointedout in claims.

In describing the invention reference will be made to the accompanying drawings in which Fig. 1 illustrates both trackway and car carried apparatus embodying one form of the invention; I

Fig. 2 shows the car-carried apparatus of a modified form of the invention; and

Fig. 3 shows still another modified form of the invention.

Referring to Fig. 1 ofthe drawings the track comprising rails l is divided into blocks by insulating jointsQ, of which the block I and the adjacent ends ofblocks H and K only have been shown. Since the various blocks are the same it is sufficient to'describe only the-apparatus of one block, corresponding devices of other blocks be ters having distinctive exponents.' 7

At the entrance end of each block is provided theusual wayside signal Z, controlled in accordance with traific'conditions in advance, in any suitable manner not spe'cifi cally shown. lfiach block is also-provided with tl eusual track circuit comprising, a track'relay T and a track battery 4; this track battery 4 has the secondary winding of a transformer 5 connected in series therewith, this transformer superimposing an alternating train control current on the track circuit direct current for reasons moreclearly pointed out hereinafter It should be noted that the circuit of the primary winding ofthe transformerfi at the exit end of a 'iarticular block-is open at the front contacts 6 of the track relay"T,'when the next block in" advance isoccupied. This in order to manifest on a train in a particular block the occupancy of the" block next in advance. Also, for a short distance atthe exit end of each blockisprovided a loop having its wires disposed adjacentthe track rails so as to simulate the fiow oi' current in such track rails when current is flowing in the loop. This loop is constantly energized from. a transformer 7. The transformers 5 and 7 receive their energyirom a transmission line TL 5 designated by like reference characsupplied with energy from an alternating current generator AC.

On eachtrain is contained a main control relay CH- of any suitable type, but preferably of the polyphase inductive type, having windings 1O anddl. which areenergized respectively by the coils of track elements l2 and113, the current of which is amplified by a suitable amplifier A. The electrical constantsiot the circuits and the amplifier A described are such that current flowin down onettrack rail and back h g throu h the other roduces currents dis laced in phase and flowing in coils 10 and 11 of relay GR, so as to cause the contacts of the control relay CR to assume the r ght hand normal position, asshown 1n thedrawi'ngs.

inn

For a more detailed description of this phase of applicants invention attention is directed to the patent to W'. W. lVenholz No. 1,692,361 dated November 20, 1928. l/Vith no current flowing in the track rails the contacts of the control relay CR assume the pendent position, and with currents flowing in the same direction in the two track rails the control relay Cit assumes the reversed dotted position. From these considerations, it is noted that with the train travelling in a clear block the control relay GR assumes its right hand energized position, with a train travelling in a caution or danger block the control relay CR assumes its deenergized position, and with stray alternating current flowing 1n same direction in the two track rails the control relay CE is caused to assume its reversed dotted position.

It is apparent from the drawings that the green lamp energized under clear traitic conditions, and the red lamp R is energized under caution and danger trailic conditions through the contact 15 01" the relay CH.

The car-carried apparatus also includes the usual air brake mechanism (not shown), two electro-pneumatic valves EPV and EPV a reset valve having a handle 20, an acknowledging valve having a handle 21, a check valve 22, an air switch AS and a reset reservoir 23. Under normal clear trafiic conditions the electro-pneumatic valve EPV is energized throu h the following circuit beginning at the terminal B of a suitable battery, wire 26, contact 27 of relay CR, wire 28, winding of the device EPV to common return wire C connected to the other terminal of said battery. It is believed that the apparatus can be best explained by consid ering the operation of the system.

Fig. operation-With the apparatus of Fig. l in its normal condition, as shown, fluid pressure may flow from a suitable main reservoir MR (not specifically shown) through pipe 30, acknowledging valve 31 having a handle21, pipe32, valve 18 opening into a chamber of the electro-pneumatio valve EPV pipe 33, check valve 22, pipes 34 and 35, to the sylphon or expansible chamber 36 of the pneumatic relay PR. Incidentally, pressure fluid may also flow through the pipe 37 and reset valve 38 to the reset reservoir 3. With the sylphon chamber 36 expandd the valve 40 of pneumatic relay PR is seated and the valve 41 is unseated, thus permitting pressure fluid to flow from the main reservoir through pipe 42, chamber of the pneumatic relay PR, pipes 43 and 44 to suitair switch AS is expanded thus causing closure of contacts 46.

It now the train enters the block I with the block K in advance thereof occupied by another train, no alternating current is detected on the rear train and the control relay CR assumes its de-energized conditions. De-energization of the control relay CR breaks the energizing circuit for the device EPV and completes the energizing circuit for the device EPV he circuit for the latter of which may be traced as follows z-beginning at the terminal B, contact 15 of the control relay GR assum ing its Clo-energized position, wires50 and 51, winding of the device EPV wire 52, contacts 46 to common return wire C connected to the other side of the source containing terminal B. l/Vith the device EPV assuming its energized condition fluid pressure may flow from the main reservoir MR through pipe 54, valve 48 in chamber of the valve EPV pipes and 56 to the chamber having a stick valve 5'? therein, to atmosphere. The piston 57 in the chamber 60 is loose fittin so built up in pipe 56 unless first this piston 57 is manually placed on the valve seat 57, after which no air can escape and the trapped air will hold the piston 57 down and will expand the sylphon chamber 59, thus making 57 a valve that will stick closed.

If the engineer is alert, as he should "be in response to the sounding of the whistle W on the electro-pneumatic valve EPV which is sounded due to air exhausted from the chambers 23 and 36, when this valve is deenergized, he will depress the handle 21 of the acknowled ing valve 31 and will thereby close the stick valve 5'? which will remain closed in response to pressure built up in pipes 55 and 56, and will cause this pressure to flow through pipe 58 to the sylphon chamber 59, thereby returning the valves in the electro-pneumatic valve EPV to normal. The engineer is, of course, required to return the handle 21 to its normal position in order to allow main reservoir pressure to flow through the valve 31, pipes 32, 33, 34, and 35 to the pneumatic relayPR. In so do ing the stick valve 57 remains closed by the built-up pressure. t is thus seen that the acknowledging handle 21 is protected against misuse and cannot be tied down, since it must be returned to its normal position for reasons just mentioned, the stick valve 57 remaining closed against the pressure of spring 53 by reason of the pressure existing in pipe 56. The train may thus travel through the caution block 1 without the presence of alternating current flowing in the track rails.

When the train in question reaches the end of the block I, having moved n the normal direction of traffic as indicated by the arrow,

e0 that the air may leak through between it and the chamber 60, and pressure cannot be the relay GR is caused to assume its normal position as soon as the car elements 12 and 13 intercept loop 8 This energization of the control relay CR reapplies current to the winding of the device EPV and de-energizes the winding-of the device EPV lVith the device EPV tie-energized pressure is exhausted to atmosphere from the pipes 55 and ance by depressing the handle 21, and in av manner as already described may supply pressure to the sylphon chamber 36 through the device EPV held in its normal position pneumatically by pressure existing in the sylphon chamber59. It is of course understood that the control relay CR cannot receive energy from the track upon its entrance into block K, because this block is occupied by another train ahead which other train shunts the alternating current, from one rail to the other and prevents it from reaching the rear train. Should the engineer have failed tomanifest his, vigilance and thereby not have closed the stick valve 57 by depression of the han die 21, his failure to act preventing pressure building up in the sylphon chamber 59, the electro-pneumatic valve EPV would have assumed its de-energized position thereby permittingthe pressure in sylphon chamber 36 to escape through the leakage port: 24 in check valve 22 and through the whistle W,

sounding the same. It is to be understood that the acknowledging handle 21 when depressed will seat the loose fitting piston 57 in chamber, 60 on seat 57, thus closing the valve 5757 which will then stick closed by trapped air pressure. This failure to act would have caused the pneumatic relay PR to have been actuated after a predetermined time depending upon the size of the leakage port 24:. Such actuation of the pneumatic relay- PR would of course effect a brakeapplication by venting pipe 44, and would effect opening of contacts 46, thereby preventing energization or effecting de-energization, as the case may be, of the electro-pneumatic valve EPV l Vith the contacts 46 once opened, it is no longer possible to energize the device EPV and it leaves the engineer helpless to prevent a brake application and the train will be brought to a stop. When the train has been brought to a stop the engineer may alight to the ground and operate the reset handle 20 to its dotted position, thereby charging the reset reservoir '28 to main reservoir pressure as is obvious from the drawings. If the engineer then returns the rest handle 20 to its normal position the pressure stored in chamber 23 flows to the sylphon-chamber 36, and thereby restores the pneumatic relay PR to normal, and in turn causes restoration of the air switch AS, which in turn applies current to the electro-pneumatic valve EPV? The engineer may then depress the handle 21 of the acknowledging device and cause pressure tobe built of in the sylphon chamher 59, and effect restoration of the valve EPV a it is thusnoted that the reset valve 38 is protected against misuse in that it must be returned to its normal position to connect the reset reservoir23 to the sylphon chamber 36, and if this had not been done when the next change to non-clear conditions 00- curs the time of venting out chamber 36 through the restricted port 2& would be reducedf to such an extent that the brakes would be applied even though the engineer :35

were to perform his acknowledging act. Further the engineer is penalized for allowing a brake application by reason of the fact that he must alight to the ground to effect resetting of the apparatus to normal.

Fig. 2-0pemi0n.In view of the detailed description of thevarious devices of the carcarried apparatus shown in Fig. 1, and the manner in which the control relay GR is controlled in accordance with traffic conditions 435 and the manner in which energy is transmitted from loop circuits at the end of blocks,

and also by reason of the similarity of the apparatus used, it is deemed sufficient to describe only the operation of the modifiedaoo forin of the invention shown in Fig. 2 of the drawings. It maybe stated that the results accomplished by the arrangement shown in Fig. 2 are substantially the same as that of Fig. 1, the principal distinction being that the acknowledgi'nent and reset functions are accomplished electrically instead of pneumatically. For this reason, an acknowledging push button 65 and areset push button 66 have been provided.

Under normal clear traffic conditions the green lamp G is illuminated by a circuit readily traced in the drawings and including a contact 15 of the control relay CR. Likewise the electro-pneumatic valve EPV which is constructed as the corresponding device in Fig. 1 except that the sylphon chamber 59 is omitted, is energized through the following circuit :beginning at the terminal B, wire 26, contact 27 of the con- .by permitting'fluid pressure to flow from main reservoir MR, pipe 32, chamber of de-- vice 'EPV pipe 33, ball 25 of the check valve 22, pipe 3%, to capacity tank 23 and sylphon chamber 36. With pressure in the sylphon chamber 36 the brakes are 'maintained released for reasons as heretofore described.

if new the train in question enters caution territory, and the relay CR assumes its deenergized condition, for reasons already given, the dc ice EPV is die-energized and pressure fluid which may ilow from the chambers 23 and 36 escapes through the restricted opening 24 in check valve 22 through the valve chamber and whistle W to atmosphere, thus sounding the whistle TW to inform the engineer that he must perform an acknowledging act to prevent an automatic brake application. if the engineer is alert and immediately acts and depresses the acknowledging push button 65 he may avail himself of the use of the acknowledging relay by completing the following pick-up circuit for this relay Allr beginning at the terminal B of a suitable source of current, wire 7%, contact 16 of th control relay GR in its pendant position, wires 75 and 76, push button contact 77 of the acknowledging push button 65, wires 78 and 79, winding of the acknowledging relay AR, through wires 80 and 81 to common return wire G. l Vith the acknowledging relay All once energized it is maintained energized through its stick circuit including its own front contact 82 and contact 16 of the control relay CR, which circuit may be readily traced in the drawings. t is, of course, understood that if the engineer is not alert to the extent of allowingcontacts 46 of AS .to open before he depresses the push button 65 to pick up the relay AR, this operation will avail him nothing, this because closure of contact 86 of re lay AR cannot close the auxiliary circuit for the deviceEPV with the contacts 46 open.

The engineer may now allow the return of push button 65- to its normal oosition by the action of a suitable spring (not shown), in which event the following circuit for thedevice EPV is completed :beginning at the terminal l3, wire 8%, contact 46 of the air switch AS, wire 85, front contact 86 of the acknowledging relay All, wire 87, contact 71 of the acknowledging push button 65, wire 72, winding of the device EPv to common return wire C. The train may thus proceed through the caution block even though there is no current flowing in the track rails, and by reason whereof the control relay GR is in its (lo-energized condition. In this connection it should be understood that the size of the leakage port 24 in check valve 22 and the volume of the capacity tank 23 are such, that the time required for fluid pressure to escape from sylphon chamber 36 to an extent to allow spring 39 to open valve l0 and close valve ll is sufiicient to permit the engineer reclosing the contact to acknowledge and reapply current through the device EIPV Also, it should be noted that the acknowledging push button 65 is protected a ainst misuse such as tying down, in that the device EPV cannot be energized so long as the push button is maintained depressed, this by reason of the normally closed contact "2'1 thereof. Although this contact 71 may be construe-ted to open only after a d of time following depression of push it may if desired be connected di rectly to the push button and open immediately.

Shoal engineer have failed to manifest. his 1' nce, that is, should he have dethe acknowledging push button 65 too late, the pneumatic relay PE would have ed the pipe shot a brake applica- .1, and such venting would have caused the AS to open its contact 46, thereby the engineer by reason of his delay including contact 46. Under "one the train is of course brought an automatic brake application, ineer must eith r wait until trafiic n advance clear up and the control rela GR is re-en-ergized, or he must alight to the ground and operate his reset push button 66, in which event the following circuit for th device EPV is completed beginning at no terminal B, wire 90, contact 91, the reset push button 66, wire 92, contact Stiof the acknowledging relay AR, which was picked up in response to late depression of the acknowledging push button 65, wire 87, contact 71 of the acknowledging push button 65, wire 72, through the winding of the device EPV to common return wire 0. The engineer is required to maintain the reset push button 66, which is only accessible from the ground, closed for a time period suliicient to build up pressure in the ca acity tank 23 and in sylphon chamber 86 to affect restoration of the pneumatic valve PR. As soon as this valve PR is restored to normal (as shown) pressure is also built up in the sylphon chamber 4-5 of the air switch AS, thus and in turn the auxiliary circuit for the device EPV heretofore traced. The engineer may new release the reset push button 66, return to the engine and proceed until he reaches the next wayside signal.

Fig. 0pcratc'0n.For reasons stated in connection with the description of Fig. 2 of the drawings it is deemed unnecessary to specifically describe the modified construction shown in Fig. 3, it being sufficient to describe the operation of this mociiied construction. Referring to Fig. 3 of the drawings the device EPV which is identical to the one shown in Fig. 2 of the drawings, is normally, that is, under normal clear traflic conditions,

energized through the following circuit beginning at the terminal B, wire 26, con tact 27'of the control relay GR in its normal energized conditiomwires 68 and 94, contact 71 of the acknowledging push button 65, wire 95, winding of the device EPl wires 96 and 97, contact 98 of the control relay CR, wire 99 to the common return wire C- Let us now assume that the train in question enters a caution block in which case, for reasons already given, the control relay CR assumes its d e-energized condition, thus causing the circuit for the device EPV just traced to be broken at the contacts 27 and 98 of this control relay CR. With the device EPV in its de-energized condition and with valve 18 seated and valve 19 unseated, the whistle W is sounded by reason of the escape of air from the capacity tank or reservoir 23 through the port 24 of the check valve 22. An appreciable period of time is required to allow the pressure tobe materially reduced in this capacity tank '23,.this time being sufficient'to allow the engineer to re-energize the 1 device EPV in a manner presently "to be described.

The engineer if alert will in response to l the sounding of the whistle W depress the acknowledging push button and complete the following circuit for picking up acknowledging relay AR before the circuit for EPV (see Fig. 3) is broken at contact 46 of air switch ASE-beginning at the terminal B, wire 74, contact 16 of the control relay OR in its de-energized condition, wires 100 and 101, contact 77 of the acknowledging push button 65, wires 102and 103, winding of the acknowledging relay AR, to common return wire C. 'W'ith' the acknowledging relay AR energized the following stick circuit is come pleted :beginning at the terminal .13, wire 74, contact 16 of the control relay CR, wires 1'00, 101, and 10 1, stick contact 82 of the acknowledging relay AR, wires 105' and 103, winding of theacknowledging relay AR, to common return wire C; There is still another energizing circuit for the valve 'EPV namely, the circuit 26, 2'7, 68, 9.4,

71 and 95,winding of EPV 96, 108 and 46,

but this circuit is of no importance since if contact'27 is closed then contact"98'is also closed, and it is immaterial whethenor not contact 46 is closed. In other words, the circuit just traced is merely incidental.

With this stick circuit completed the en- 5111861 may return the acknowledging push knowledging relay AR, wires 107 and 94, contact 71- of the acknowledging push'buiton .65, wire 95, winding of the device nrv wires 96 and 108,.contact 46Jof the air switch 'AS, to common return wire (1. With this auxiliary circuit for the device EPV completed the valves 18 and 19 of this device are, restored to their normal position thereby recharging the capacity reservoir 23 before the pneumatic valve PR is operated. :TllQ train is thus permitted to proceec through the caution block with the control relay GR in its de-energized condition. When the train reaches the acknowledging loop at-the end ofthe cautioirblock (seeFig; 1) the In the event the engineer is not alert and fails to operate the acknowledgingpush' button 65 within the time required, the reservoir 23 will have been vented to suchan extent as to operate the pneumatic relay PR, thereby effecting aibrake application and. opening the contact 16 ofthe airflswitch AS, so that the device EPV cannot be manually ret stored. With the contact 16 once opened, acknowledgment by the engineerwill be ineffective, for even though the acknowledging relay AR is picked upthe auxiliary circuit heretofore traced and including the contact 46 willremain open, and the brakes will remain applied. The train is thus, brought to a stop and the engineer must either-wait until traffic conditions have cleared up, so as to complete the original circuit for the device EPv or the engineer must alightto the ground and operate the pneumatic reset device, comprising the valve 38, operated by a handle 20. h V 7 If the engineer'alighis tothe ground and operates-the handle 20, which .is only accessible from the ground, to the dotted position,

main reservoir pressure may flow from such reservoir to the capacity tank 23. After this tank 23 has been fully charged the handle 20 may bore-turned to itsfnormal position in which eventfluid pressure will flow from tank 23 to the sylphon valve 36,; therebyrestoring the pneumatic relay PR to-normal. With-this pneumatic relay PR once restored to its normal condition pressure is applied to pipe 44' leading to :the brake control ap paratus to releasethe brakes, and to the sylphon chamber 45- of the air switchi AS,

ton-65 and picked up his acknowledging relay AR, the ':auxiliary-circuit heretofore traced and including the contact 86 of relay AR' andthe contact 46*of the air switch AS is again completed, thus permitting the train to proceedto thenext signal in advance.

"and since the engineer has presumablyah ready actuated his acknowledging push but- Applicant has thus described three forms of the invention, comprising a permissive train control system requiring an acknowledging act by the engineer at each caution and each of a plurality of successive danger signals, and has shown by these modified constructions how the acknowledging and reset functions may be accomplished either electrically or pneumatically and'has illustrated how the engineer may be penalized for his failure to perform an acknowledging act when he should manifest his vigilance either by pneumatic or electrical apparatus;

it is desired to be understood however that 7 these various constructions have been selected to illustrate how the invention may be per formed, and it is further desired to be understood that the systems shown and described have not been selected to illustrate the exact construction preferably employed in practicing the invention, but that various changes, modifications, and additions may be made to adapt the invention to local conditions, all without departing from the spirit or scope of the invention or the idea of means underlying the same except as demanded by the scope of the following claims.

What I claim is 1. In a continuous inductive train control system of the type wherein the engineer must manifest his vigilance at each caution and stop signal to prevent a brake application, the combination with a car-carried relay responsive to the flow of current in the track rails, an electro-pneumatic valve controlled by said relay and energized when said relay is energized to charge a chamber with fluid pressure and which valve if de-energized vents said chamber through a restricted opening, a pneumatic relay controlled by the pressure in said chamber which in response to such pressure maintains suitable brake applying means inactive whereby'the venting of said chamber through said restricted opening causes a delayed brake application in response to de-energization of said main relay, supplemental means for applying fluid pressure to said chamber if the engineer manifests his vigilance, and trackway means for causing the flow of current in the track rails throughout each clear block and for a short distance near the end of each caution and danger block.

2. A continuous inductive itrain control system of the type wherein the engineer must manifest his-vigilance at each caution and stop signal to prevent a brake application,

the combination with a car-carried relay responsiveto the flow of current in the track rails, an electro-pneumatic valve controlled by said relay and energized when said relay is energized to charge a chamberwith fluid pressure and which valve if die-energized vents said chamber through a restricted opening, a pneumatic relay controlled by the pressure in said chamber which in response to such pressure maintains suitable brake applying means inactive, whereby the venting of said chamber through said restricted open- 1 a 11 11 a,] ing causes a re ayec lane application in response to de-energization of said relay, supplemental means for applying fluid pres-' sure to said chamber if the engineer mani fests his vigilance, which means remains active only so long as said main relay remains de-energized, and trackway means for causing the flow of current in the track rails throughout each clear block and for a short distance near the exit end of each caution and danger block.

3. In a continuous inductive train control system of the type wherein the engineer must manifest his vigilance at each caution and stop signal to prevent a brake application, the combination with a car-carried relay responsive to the flow of current in the track rails, an electro-pneumatic valve controlled by said relay and energized when said relay is energized to charge a chamber with fluid pressure, and which valve if de-energized vents said chamber through the pressure in said chamber which in response to such pressure maintains suitable brake applying means inactive whereby the restricted venting of said chamber through said opening, causes a delayed brake application in response to deenergization of said main relay, pneumatic means for operating said electro-pneumatic valve pneumatically, acknowledging means which if operated while said main relay is de-energized maintains said pneumatic means active so long as said main relay remains de energized, and trackway means for causing the flow of train control current in the trackway throughout a clear block and at the exit end of each caution and danger block.

l. in a continuous inductive train control system of the type wherein the engineer must manifest his vigilance at each caution and stop signal, to prevent a brake application, the combination with a car-carried relay responsive to the flowof current in the track rails, an electro-pneumatic valve controlled by said relay and energized when said relay is energized to charge a chamber with fluid pressure, and which valve if de-energized vents said chamber through the restricted opening, a pneumatic relay controlled by the pressure in said chamber which in response to such pressure maintains suitable brake applying means inactive, whereby the restricted venting of said chamber through said opening causes a delayed brake application in response to de-energization of said main relay, pressure operated means for operating said electro-pneumatic valve pneumatically, acknowledging means which if operated while said main relay is de-energized maintains said pressure operated means chargedwith fluid pressure through,

teaser the medium of a stick valve opened by a drop in fluid pressure of said pressure operated means, and trackway means for causing the flow of train control current in the track rails throughout a clear block and at the exit end of each caution and danger block.

5. In a continuous inductive train control system of the type wherein the engineer must manifest his vigilance at each caution and stop signal to prevent abrake application, the combination with a: car-carried main relay responsive to the flow of current in the track rails, anelectro-pneumatic valve controlled by said relay and energized when said relay is energized to charge a chamber with fluid pressure, and which if de-energized vents said chamber through a restricted opening, a pneumatic relay controlled by the pressure in said chamber which in res onse to such pressure maintains suitable Brake applying means inactive, whereby the restricted venting of said chamber through said opening causes a delayed brake application in response to de-energization of said.

main relay, pressure operated means for operating sald electro-pneumat1c valve pneumatically, acknowledging means which if operated while said main relay is de-energized maintains said pressure operated means charged with fluid pressure through the medium of a stick valve which valve is opened by a drop in fluid pressure, means for releasing pressure from said pressure operated means upon re energization of said main relay, and trackway means for causing the flow of train control current in the track rails throughout a clear block and at the exit end of each caution and danger bloclr.

6 Car-carried apparatus for automatic train control systems comprising, a valve, an electro-magnet for directly mechanically operating said valve, fluid pressure responsive means for directly mechanically operating said valve, brake controlling means controlled by said valve,a relay controlled in accordance with tratlic conditions for controlling the .contlnulty of the energizing circuit for said electro-magnet, and manually Y operable acknowledging means forapplying pressure to said pressure responsive means.

7. Car-carried apparatus for automatic tram controlsystems comprlsing, a valve, an electro-magnet for directly operating sald valve, pressure responsive means for directly operating said valve, brake controlling means controlled by said valve, a mam relay controlled in accordance with traffic condltlons for when energized to energize said electromagnet, an 'electro-pneumatic valve ener ually operablestick valve connected to said pressure responsive means which stickvalve if manually closed is held closedby pressure I control meansto normal.

applied to said pressure responsive means,

whereby upon de-fenergization of said main relay manual operation ofsaid stick valve is necessaryto prevent anapplication ofthe brakes. I a

8. Car-carried apparatus for automatic train control systems comprising, a valve, an, electro-magnet for directly operating said valve,1pressure responsive means for directly operating said valve, brake cont-rolling means controlled by'said valve, a main relay controlled accordance with trafi'ic conditions for when energized to energize said electro-magnet, an electro-pneumatic valve energized when said mam relay s de-ener- 'gized to conduct fluid pressure to said presare responsive means,,andanormally open manually operable stick valve connected to saie pressure responsive means which stick valve if manually closed isheld closed by pressure applied to said pressure responsive means,whereby upon de-energization ofsaid main relay manual operation of saidstick valve is necessary to prevent an application otthebrakeaand reset means accessible only from the groundfor restoring said blfake 9. vCar-carried apparatuslfor automatic train control s stems com risin fluid resfroin the ground for connecting said fluid pressure operated means to a chargedreser voir .toeffect closureof said contact, and manually controllable means for closing an auxiliaryv circuit through said electro-pneumatic .valveand including said contact.

i 10. Car-carried apparatus for automatic ain pn r ys emsp s ns, d r fesure operated brake control means, anelectr rn unia i va reW c if ne g zed p pressure to said fluid ,pressure. operated valve through a ch e e av ng are tr d bypass,a pressure responsivecontactclosed only when fluid pressure is applied to said'fiuid pressure operated 1neans,a circuit, for energlzmg said 'GlGClZIO-PIIGUHlflUC valve closed under favorable traffic cond1t10ns.aheadand "including said contact, means accessible'only from the roundfor connectin said fluid b pressure operated means to a charged reservoir to effect closure of said contact, and

manually-controllable means for closingan auxiliary --eircuit including said contact through said electro-pneumatic valve. 11. Oar-carriedyapparatus for automatic train control systems comprising, fluid pres-.

sure operated brake control means, an electropneumatic valve which if energized applies pressure to said fluid pressure operated valve, a pressure responsive contact closed only When fluid pressure is applied to said fluid" pressure operated means, a circuit for energizing said electro-pneumatic valve closed under favorable trafic conditions ahead and including said contact, means accessible only from the ground for connecting said fluid pressure operated means to a charged reservoir to ellect closure of said contact, and manually controllable means for closing an auxiliary circuit through said electro pneumatic valve, said circuit including said contact and a normally closed contact ofsaid manually controllable means, whereby said manually controllable means is protected against misuse, in that it must after operation be returned to normal to permit closure of said auxiliary circuit.

12. Car-carried apparatus for automatic train control systems comprising, a normally charged pipe which if vented effects an auto matic brake application, normally energized electro-pneumatic means for maintaining said pipe charged, means controlled from the trackway and efiective under clear traffic conditions to maintain said electro-pneumatic means energized, and manually controllable pneumatically operated means efiective only under non-clear trafiic conditions and then only if the brakes have not yet been automatically applied for maintaining said pipe charged.

13. Car-carried apparatus for automatic train control systems comprising, a normally charged pipe Which if vented efiects an automatic brake application, normally energized electro-pneumatic means for maintaining said pipe charged means controlled from the track- Way and effective under clear traflic conditions to maintain said electro-pneumatic means energized, and manually controllable pneumatically operated means effective only under .non-clear trafiic conditions and then only if the brakes have not yet been automatically applied for maintaining said pipe charged, and means for protecting said pneumatically operated means against misuse.

In testimony whereof I aflix my signature.

WADE H. REICHARD.

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