US1864481A

US1864481A - Railway traffic controlling apparatus

Info

Publication number: US1864481A
Application number: US524365A
Authority: US
Inventors: Roy E Baker
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-03-21
Filing date: 1931-03-21
Publication date: 1932-06-21
Anticipated expiration: 1949-06-21

Description

Patented June 21, 1932 PATENT @FF'EQE ROY E. BAKER, OF READING, MASSACHUSETTS RAILWAY TRAFFIC CONTROLLING vAZPIPARA'IUS Application filed March 21, 1931. Serial .No. 524,365.

invention relates to railway traffic controlling apparatus, and particularly to automatic train control systems of the intermittent inductive and continuous inductive types.

' More articularl m invention relates to the train carried portion of such systems.

One object of my invention is to provide train carried apparatus having a minimum number of constituent parts so arranged that the train may be operated in territory provided with either intermittent or continuous train control apparatus.

I will describe two forms of apparatus embodying my invention, and will then point C out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a view, partly diagrammatic and partly cross sectioned, illustrating one form of railway traffic controlling apparatus embodying my invention. Fig. 2'is a similar view showing a modified form of the apparatus illustrated in Fig. 1, and also embodying my invention.

Similar reference characters refer tosim- I ilar parts in both views.

Referring first to Fig. 1, the

reference characters

1 and 1 designate the track rails of a stretch of rail-way track over which traffie normally moves in the direction indicated by the arrow. These track rails are divided,

7 by means of insulated joints 2, into a plurality of track sections, only three of which D- E, ill-F and F-G are illustrated in the drawing. Each track section is provided with the usual track circuit comprising a suitable'source of current, here shown as a track battery 3, connected across the rails adjacent the exit end of the section, and a track relay, designated by the reference character T with an exponent corresponding to the location, connected across the rails adjacent the entrance end. of the section.

The rails of section D-E are also supplied with alternating train controlling current under the control of traffic conditions in advance of the section.- As here shown, this latter current is furnished by interposing between the track battery 3, and one rail 1 of the section, the secondary 4: of a transformer H, theprimary 5 of which is at times supplied with alternating train controlling current from the secondary 7 of a transformer J. The primary 8 of transformer J is constantly connected with a source of alternating current which is not shown in the drawing. The circuit for primary 5 of transformer H includes a front contact 6 of track relay'T and it will be apparent, therefore, that alternating train controlling current is supplied "to the rails of section DE when section EF is unoccupied, but-not when this section is occupied.

Located adjacent the entrance end of section FG is atrackway inductor K of the usual form commonly employed in intermittent'inductive train control systems, and comprising a inagnetizable core 9 provided with a winding 10. As here shown, the circuit for winding 10 is controlled by a front contact 11 of track relay T so that the circuit for this winding will be closed when section FG is unoccupied, and opened when this section is occupied.

As shown in the drawing, section D-E is occupied by a train W. Located in advance of the forward axle of this train is a receiver L of the usual form commonly employed in train control systems of the continuous inductive type, and comprising two

inagnetizable cores

12 and 12 disposed in inductive relation with the

track rails

1 and 1 respectively, and provided with windings 13 and 13 'The windings 13 and 18 are included in a receiv ing circuit at, these windings being connected in series in this circuit in such manner that the potentials created in these windings by alternating current flowing in opposite directions in the two track rails, are additive.

The currents induced in the receivingcircuit a are utilized to control the supply of current to a relay M, suitable amplifying apparatus N preferably being interposed between the receiving circuit and the relay windings as illustrated in the drawing.

The train carried apparatus also includes a second receiver P of the usual form commonly employed in train control systems of the intermittent inductive type, and compris ing' a magnetizable core 14 provided with a primary winding 15 and a secondary winding 16. The receiver P is so located as to while the train is in motion.

register with the trackway inductor K in the usual and well known manner. The train carried apparatus further includes a polarized relay S of the usual type commonly employed in intermittent inductive train control systems, a checking relay U, a slow releasing acknowledging relay V, and a brake magnet X. The brake magnet X controls the brakes in such manner that an automatic brake application occurs at the expiration of a given interval of time following the deenergization of magnet X. Associated with the brake controlling apparatus is a pneumatic relay Z which controls a contact 22 in such a manner that this contact is normally closed but becomes opened upon the initiation of an automatic application of the brakes. 7

When magnet X is energized, it connects a timing reservoir with a suitable source of fluid pressure not shown in the drawing through the medium of a valve 21. Reservoir 20 is connected with a relay valve Y so that, when this reservoir is charged, the valve is depressed, and pneumatic'relay Z is connected by a pipe 23 with a source of fluid pressure; contact 22 is then closed. Pipe 23 is also connected to apparatus (not shown) which causes an automatic application of the brakes when this pipe is opened to atmosphere. *When magnet X becomes deenergized, timing reservoir 20 will be opened to atmosphere through a restricted orifice 24, and also through a whistle 25 which gives an audible indication to the engineman. After a given interval of time, such as six seconds, valve Y will reverse, thereby venting pipe 23 to atmosphere, and this will cause an automatic application of the brakes, and will also cause contact 22 of relay Z to open.

The train carried apparatus further includes an acknowledging switch A and a reset switch B. As here shown, the acknowledging switch A comprises two normally closed contacts 25-25 and 26-26, and two normally open contacts 26-26 and 27-27? Similarly, the reset switch R comprises two normally closed contacts 28-28 and 29-29% and two normally open contacts 30-30 and 29-29 The reset switch R will usually be located on the train in such a position that it is inaccessible to the engineman The train carried apparatus also includes a resistance element 31, the function of which will be made clear hereinafter.

The main circuit for the primary winding 15 of the receiver P passes from terminal B of a suitable source of direct current not shown in the drawing, through normally closed contact 26-26 of acknowledging switch A, normally closed cont-act 29 29 of reset switch R,

wires

32 and 33, primary winding 15, wire34, winding of checking relay U,-and wire 35, to the other terminal G of the source. The normal circuit for the secondary winding 16 of the receiver P is from terminal B through normally closed contact 26-26 of acknowledging switch A, normally closed contact 29-29 of reset switch R, wire 32, normal contact 17-19 of relay S, wire 36, winding of relay S, wire 37, secondary winding 16 to an intermediate point in the primary winding 15, and thence through the right hand portion of this winding, wire 34, the winding of relay U, and Wire 35 to terminal C.

Acknowledging relay V is provided with an acknowledging circuit which passes from terminal B through normally open contact 26-26 of acknowledging switch A,

wires

37 and 38, normal contact 19-17-18 of relay S, wire 38 back contact 39-39 of relay M, wires' 40, 41 and 42, contact 22 of pneumatic relay Z, wire 43, normally open contact 27-27 a of acknowledging switch A,

wires

44 and 45, winding of relay V, wire 46, back contact 47 -47 of relay M, and

wires

48 and 49 to terminal C. Relay V is also provided with a reset circuit which passes from terminal B through normally closed contact 26-26 of acknowledging switch A, normally open contact 29-29 of reset switch R, wire 38, normal contact 19-17-18 of relay S, wire 38, back contact 39-39 of relay M,

wires

40, 41 and 50, normally open contact 30-30 of reset switch R,

wires

51, 44 and 45, winding of relay V, Wire 46, back contact 47-47 of relay M, and

wires

48 and 49 to terminal 0. Relay V is further provided with a stick circuit which passes from terminal B through normally closed contact 26-26 of acknowledging switch A, normally closed contact 29-29 of reset switch R, wire 32, normal contact 17-18 of relay S, wire 38, back contact 39-39 of relay M, wires and 52, front contact 81 of relay V, wire 45, winding of relay V, wire 46, back contact 47-47 of relay M, and

wires

48 and 49 to terminal C.

Magnet X is provided with a circuit which passes from terminal B through normally closed contact 26-26 of acknowledging switch A, normally closed contact 29-29 of reset switch R, wire 32, normal contact 17-18 of relay S, wire 38, front contact 39-39 of relay M, wire 53, back contact 54-54 of relay V, wire 55, normally closed contact 28-28 of reset switch R, wire 56, normally closed contact 25-25 of ackowledging switch A, wire 63, winding of magnet X, front contact 57 of relay U, wire 58, back contact 59 59 of relay V, wire 60, front contact 47-47 of relay M, and wires 48 and 49-to terminal C. Magnet X is also provided withv a circuit which passes from terminal Bthrough wire 61, front contact 5454 of relay V, wire 55, normally closed contact 28-28 of reset switch R, wire 56, normally closed contact 25-25 of acknowledging switch A, wire 63, winding of magnet X, front contact:5'Z of checking relay U, wire :58,-front contact 59-59 of relay V, and wire-4:9 to terminal C.

The train carried apparatus also comprises twoindicating devices here shown as. electric lamps 6.4 and 65which indicate pro.- ceed and stop, respectively, when illuminated. Lampoa is provided with a circuit which passes from terminal Bthroughinormally closed contact 2626 of acknowledging switch A, normally closed contact 29.29 of :reset swith R, wire 32, normal contact 17-18 of relay S, wire 38*, front contact 39 .39 of relay M, wire 66, filament of lamp 6.4, wire '67, frontcontact Pi-47 of relay M, and

wires

48 and 49 to terminal C. Lamp 65 is provided with a circuit which passes from terminal B, through normally closed contact 26-26 of acknowledging switch A, normally closed contact 2929 of reset switch It, wire 32, normal contact 17-18 of relay S,wire 38, back contact 3939 of relay M, wire 68, filament of lamp 65, wire 69,; back contact 47t7 of relay M, cand wires 48and 49 to terminal C. v Y r The operation of the entire apparatus is asfollows: As shown in the drawing, section EF is unoccupied,- and train controlling current is therefore suppliedytothe

track rails

1 and 1 of section D-iE, so-that relay M is energized. Acknowledging relay V is deenergized. Relay 3 is energized by virtue of the normal circuit previously traced for the secondary 16 0f receiver R which circuit is closed at normal contact 11-119 of rela-y'S. Relay U is energized by virtueof the main circuit previously traced for the primary-l5 of receiver .P. Since rclaysM, S and U are all energized and relay V is deenergized, magnet X is energized. The timing reservoir is therefore charged with fluid pressure, and the relay valve Y. occupies its lower position in which pipe 23, is connected with the source of fluidapres sure. Contact 22 of'pneuma-ticzr'elay Z- is closed. It follows that as .longas that part of section D-E in advance of the train V, and section E-F are unoccupied, the train may proceedthrough the remainiderof section DE without incurring an automatic application of the brakes. c

I will now assume-that the supply oftrain controlling current to the receiver L is cut ofi, due, for 1 example, either -tothe presence ofa train in section D-E between-the train W and the exit end of the section, or )to train ,in section EF which causes track relay T to become deenergizedu Underthese,

conditions relay M becomes deenergized,

thereby opening, its frontcontacts 39739 and lfi -e 7 and; closingits back contacts 393.9?-and 4747?. The opening of-front contacts .39-39 and.-4JT47 of relay M' interrupts both the circuit, for the proceed amp (Ha d. theci u i for magaet X, O- hat;

the lamp 6% becomes extinguished and the magnetbecomes deenergized. The closing-of back contacts 39*39" and 4747 of relay M completes the circuit previously traced for the stop lamp 6'5, and'this lamp becomes lighted to indicate that tra'lfic conditions in advance are dangerous; The deenergization of magnet X will, after the predetermined time interval, result in an automatic application of the brakes unlessthe engineman is alert and-reverses the acknowledging switch A before the expiration of the predetermined time interval. Assuming he does this, the acknowledging circuit previously traced for acknowledging relay V will then be closed,

and acknowledging relay V will therefore become energized. lVhen relay V becomes energized, the circuit previously tracedfor magnet X is closed at front contacts 54-54 and 5959 of this relay, and magnet X, therefore, again becomes energized, so that reservoir 20 is againconnected with the source of fluid pressure. Furthermore, after relay V, has become energized, and the acknowledging switch A has been returned to its normal position, the stick circuit for relay V is closed, and relay V therefore remains energized, it being understood, of course, that relay V is suflicientlyslow-releasing so that it will not open its front contacts, while the switch A is, being restored to its normal position. It follows that when magnet X has been reenergized in this manner, it will, subsequently remain ener ized, and will prevent an automatic application of :the brakes. The parts will then remain in these latter conditions until atrain, controlling current is again supplied to the receiver L at which time relay M will become energized, therebydeenergizing relay V, and, hence, restoring the parts to the conditions inwhich they are illustrated in the drawing. p

I will now assume that the engineman was not alert and did not reverse the acknowledg ing switch. A prior to the automatic application of the brakes due tothe supply of train, controllingcurrentto the receiver L being cut off, Thebrake application results in normally ,closedcontact 22 .of pneumatic relay Z. being opened, so that relay V cannot beenergized by reversing the acknowledging switch A. The engineman must therefore reverse the reset switch R, which cannot be doneuntil the train has come to afull stop. When he doesthis,the reset circuit for acknowledging relay V becomes completed, and relay V therefore becomes energized so that, if the resetswit-ch is now, returned to its normal position, relayV will remain energized by virtue of its stick circuit. When relay V is energized, magnetX becomesenergized, and the brakescan be released. Ifrelay Mnow again becomes energized, relay V will become deenergized, Furthermore, when relay -M becomes energized, lamp will become ;ex

tinguished and lamp 641 will become lighted. The parts will then be restored to their normal conditions in which they are illustrated in the drawing. I

When the train passes out of continuous control territory, as is the case when the train leaves section DE, the supply of current to the receiver L will, of course, be cut off so that relay M will become deenergized and, unless the engineman reverses the acknowledging switch A to energize relay V, an automatic application of the brakes will occur in the manner previously described. If the engineman does reverse the acknowledging switch A to energize relay V, however, then when the acknowledging switch is returned to its normal position, the stick circuit for relay V will be completed, and relay V will subsequently remain energized until relay M again becomes energized due to the train entering continuous control territory.

I will now assume that with relay M deenergized, with relay V held in its energized condition by virtue of its stick circuit, and with the remainder of the train carried apparatus in the condition in which it is illustrated in the drawing, the train passes an inductor K having its winding 10 open circuited. Under these conditions, while the train is passing the inductor K, the reluctance of the magnetic circuit for the receiver P will be considerably reduced, and so the flux traversing the receiver coil 14 will rapidly increase as the receiver approaches the inductor and will decrease as the receiver recedes from the inductor. This will produce a complete cycle of two alternations of electromotive force in the secondary winding- 16, and the voltage of one of these alternations will neutralize or reverse the current through. the winding of relay S thereby causing this relay to open its normal contacts. l/Vhen the contacts of relay S are opened, the stick circuit for relay V is opened, and relay V therefore becomes deenergized, and deenergizes'magnet X. The deenergization of the magnet X will, after the predetermined time interval, result in an automatic application of the brakes in the manner previously described.

If the train passes the inductor K when its winding 10 is short circuited, the magnetic coaction will be the same as before, except that the voltage induced in the receiver secondary 16 will be very much lower and will not be sufiicient to deenergize relay S. It follows that an automatic application of the brakes will not occur.

v I will now assume that after relay S has become deene-rgized due to the train having passed a. trackway inductor K having its winding 10 open circuited, the engineman reverses the acknowledging switch A, before an automatic application of the brakes octhe right hand portion of primary 15 of re-- ceiver P, wire 34, winding of relay U, and wire 35 to terminal C. This circuitis provided with a branch which passes from terminal B through resistor 31,

wires

32 and 33, and the left hand portion of primary 15 of receiver P to the right hand portion of primary 15 of receiver P. Current flowingv in this acknowledging circuit energizes relay S in the normal direction and relay S therefore closes its normal polar contact 191718. WVhen this contact is closed, the acknowledging circuit previously traced for acknowledging relay V is completed, and relay V becomes energized. The acknowledging switch may now be returned to its normal position, and relay V will subsequently remain energized by virtue of its stick circuit. As soon as relay V becomes energized, magnet X becomes energized over the circuit previously traced for this magnet, thus preventing an automatic application of the brakes. WVhen magnet X becomes energized, the parts are restored to the conditions in which they were before the receiver passed the inductor, and the train may proceed without stopping.

The function of the resistor 31 is to cause the current to divide in the two paths of the above circuit in such manner that relay S will be supplied with suflicient current to energize this relay. This would not'happen' if this resistor were not provided.

1 will now assume that the engineman does not reverse the acknowledging switch A prior to an automatic application of the acknowledging switch A, normally open 'con-' tact 29-29 of reset switch R,

wires

38 and 36, winding of relay S, wire 37*, secondary 16 of receiver P, the right hand portion of the primary 15 of receiver P, wire 34, winding of relay U, and wire 35 to terminal 0. This circuit is provided with a branch which passes from terminal B through resistor 31,

wires

32 and 33, and the left handportion of primary winding 15 of receiver P to the right hand portion of this winding. The current in this last-traced reset circuit will energize relay S in the normal direction, so that this 15, scent relay; will close; its. normal contact. With.

the normal contact 19j-1718 of relay S; closed and; the reset switch R in its reverse position, the reset circuit previously traced for acknowledging relay V is completed at the normally open contacts 29-29 and 30.--3'0of reset switchR, and relay V therefore: becomes energized. When relay V becomes energized, and reset switch R is returned: to its normal position, the circuit previously traced formagnet X. is then completed, and magnet X becomesenergized, so that the brakes can; be released. As soon as the brakes have been released, normally closed contact 22 of pneumatic relay Z becomes closed, and the parts are then restored to. the conditions-which they were in before the automatic application of the brakes: occurred.

It will be noted' that when the acknowledging switch. A. is reversed, both circuits tor'the magnet X are opened, so that, if this switch isreversed and left in the reverse position tormore than a given interval of time, an automatic application of the brakes will occur. The same thing is true of the reset switch R. It follows that neither one of these switches can be tied or otherwise held in the reverse position to defeat the object of the-system.

The function of the checking relay U is to' openthe circuit for-magnet X in case a broken wire occurs in the circuit forthe primary winding-'15 of receiver P, thereby insuring that the dangerous condition which might exist if the receiver passed an open circuited inductor K under these conditions will be prevented.

Referring now to Fig. 2,.the apparatusheres shown is similar to that shown in Fig-.. lwith the exception that the checking relay has. been eliminated and certain of the ClI'CUltS' have been rear-ranged as follows: As here shown, the acknowledging circuit foracknowledging relay V passes fromterminal-B:

through wire 7 0. normal contact 17-18 of'relays S, wire 38", back contact 3939P"ofre lay M, wires'40, 41 and 42, contact 22jofpneumatic relay Z, wire 48, normally open contact 2727 0t acknowledging switch A,

wires

44 and 45, winding of relay V, wire 46, back'contact 4747 of relay M, and wires 48 and 49' to terminal G. The reset circuit for acknowl edging relay V passes from terminal" B through wire 70. normal contact 1718 of re lay M,

wires

40, 41 and 50, normally opencontact 30-30 of reset switch R,

wires

51, 44'

and 45, winding of relay V, wire 46, back contact 47'47 of relay M. and wires 48- and 49 to terminal C. The stick circuit for relay V passes from terminal B through wire 70, normal contact 17-18 of relay S, wire 38*,

back contact 39-39" ofrelayM, wire 40, front contact 81 of relay V, wire 45, windrng of re- S, wire 38", back contact 3939 'ot relay" lay. V,.wire 46, back. contact.47:47 of relay:

M, andiwires 48': and. 49 to terminalfi. The;

The main circuit for theprimary winding:

15' of receiver P passes firom terminal. B.- through resistor 71, wires. 72- and.- 73; ballast. lamp 74, wire 75,, and primary winding- 15. to terminal C. The circuit. for the secondary winding16 of receiver P passes from terminal B through wire: 70, normal contact. 17-19: of relay S, wire 76, secondary winding 160i receiver P, wires 77; and 7.8,windingof relay; S, wires 79 and 73, ballast lamp 74, Wire 75,. and primary winding 15: to terminal P.

Theoperation of the apparatushere shownz when thetrain is in continuouscontrol tenni tory, as illustrated by section: D-E, isisub stantially the same as that previously described in. connection with Fig. 1, and. will be readily understood from an; inspection of the drawing without describing it in detail. When the: train passesout of'continuous control territory, however, as: is the case-when. the trainleaves section D,-E,,the supply of current to the relayM is of. course cutofifas previously described, and, inorder'that the. train may proceed, the engineman: must. op. erate acknowledging switch 14. to; complete. the acknowledging circuit. for acknowledging relay V. Relay V therefore; picks.1rp,..and closes its stick circuit: at its, front. center-ch81, so. that, while the train is inintermittent, con-- trol territory this relay isinormally held inits: energized. condition... Whenrelay M isdeenergized, the circuit previously tracedJfOr-the proceed lamp 64 is interrupted at. front cork tacts 3939' and 47'47' of relay M andrthecircuit for the stop. lamp 65. is completed at. back contacts 39-39 and 4747 of? relay M'. The proceed lamp. 6.4. 13 therefore; extine guished and the stop. lamp:- iszlighted.

I will now assume thatwith relaysSFand V energized and with relay M deenergiZed, the train passes an inductor having its winding 10 open circuited; Underthesezcorrditions, while the; train is. passing the; induc tor K, a complete cycle 0ftwaralternationsr of 'electromotive force: willbe'inducedin the secondary winding. 15 of. receiver? R in v the? manner described. in, COHIIGCl'iQIIJ.With.ElgZ 1 and the current due to one: of thesej:alternar-- tions will neutralize or reverse; the current through the winding of relay S; thereby causeing this relay to open its contacts. contact 17.-18 of relay S is; opened, thecir cuit: for secondary'winding- 16; of receiver? previously described but due to the tact 17--18' of relay S interrupts the stick circuit for acknowledging relay V, and relay V also becomes deenergized. When relay V is deenergized under these conditions, the circuit for magnet X is interrupted at front contacts l54 and 5959 of relay V so that'magnet X likewise becomes deenergized. The deenergization of magnet X will, after the predetermined time interval, result in an automatic application of the brakes in the manner previously described. If the train passesthe inductor K when its winding is short-circuited, the magnetic coaction will be the same as before, except that the voltages induced in the receiver secondary 16 will be very much lower and will not-be sufficient to deenergize relay S. It follows that an automatic application of the brakes will not occur. Y

I will now assume that when the relay S has become deenergized due to the receiver P passing an open circuited inductor K, the engineman reverses the acknowledging switch A before magnet X has been deenergized for a sufiicient interval of time to cause an automatic application of the brakes. Under these conditions, an acknowledging circuit is completed for relay S at normally open contact 2626 of acknowledging switch A, which circuit passes from terminal B through normally open contact 2626 of acknowledging switch A,

wires

37, 80 and 78, winding of relay S, wires 7 9 and 73, ballast lamp 74, wire 75, and primary winding to terminal C. Relay S therefore becomes energized and closes its normal contacts. As soon as contact 1718 of relay S becomes closed, the acknowledging circuit previously traced for acknowledging relay V is completed-at normally open contact 27'27 of acknowledging switch A, and acknowledging relay V therefore becomes energized and closes its stick circuit. If, now, the acknowledging switch A is returned to its normal position, the circuit previously traced for magnet X will become closed, and magnet X will therefore become energized, thus preventing an automatic application of the brakes. When magnet X becomes energized,

the parts are restored to the conditions in.

which they were before the train passed the open circuited inductor K and the train may therefore proceed. I

. I will now assume that the engineman does not reverse the acknowledging switch A prior to the automatic application of the brakes due to coaction of the receiver P with an open c rcuited inductor K. Under these condit1ons, the operation of the acknowledging switch A will energize relay S in the manner applicatlon of the brakes, contact 22 of pneumatic relay Z will now be open, and acknowledgmg relay V will therefore remain deenergized when the acknowledging switch is returned to its normal position. It will be apparent therefore, that operation of the acknowledging switch A under these conditions will not permit the brakes to be released. As a result, when an automatic application of the brakes has been incurred the engineman will not operate the acknowledging switch A but will operate the reset switch R. When he does this, a reset circuit will be completed for relay S which is exactly the same as the pickup circuit which was completed at contact 26-26 of acknowledging switch A when this switch was reversed, except that this circuit includes normally closed contact 26 26 of acknowledging switch A and normally open contact 2929 of reset switch R instead of contact 26-26 of acknowledging switch A. Relay S therefore picks up, and closes its normal contacts. As soon as normal contact 1718 of relay S becomes closed, the acknowledging circuit for relay V is completed, and relay V becomes energized and closes its stick circuit. As a result, when the reset switchE is restored to its normal position, magnet X will again become energized, and the brakes can be released. When the brakes have been released, contact 22 of pneumatic relay Z will become closed, and the parts will then be restored to the conditions in which they are illustrated in the drawing.

The function of the resistor 71 is to adjust the magnitude of the current supplied to the. primary winding P to a valve which gives the desired flux density in the core 14 of receiver P. The function of the ballast lamp 74 is to maintain a constant current in the primary and secondary windings of receiver P in case the voltage of the source fluctuates.

Although I have herein shown and described only two forms of railway traffic controlling apparatus embodying my invention,

it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway traiiic controlling apparatus comprising a first train carried relay controlled by devices located at intervals along the trackway, a second train carried relay controlled by currents supplied to the track rails, a manually operable switch on the train, an acknowledging relay on the train controlled by said switch and by said first and second relays, and a single bra re con trolling magnet on the train controlled by said acknowledging relay and by said switch.

2. Railway traffic controlling apparatus comprising a first train carried relay, means controlled by currents supplied to the track rails for at times energizing said first relay, a second normally energized train carried relay, means controlled by devices located atin-- tervals along the trackway for at times deenergizing said second relay, a normally energized brake controlling magnet on the train eliective to apply the brakes after said magnet has been deenergized for a given interval of time, means for deenergizing said magnet when either of said relays becomes deenergized, manuallyoperable means on the train effective for reenergizing said magnet ifandonly if such means is operated prior to the expiration of said given interval oi time, and other manually operable means for at other times reenergizing said magnet.

3. Railway traffic controlling apparatus comprising a first train carried relay which is controlled by currents supplied to the track rails and a second train carried relay which is controlled by devices located at intervals along the trackway, a brake controlling magnet on the train effective to applvthe brakes after the-magnet has been deenergized for a given interval of time, a normally closed contact on the train, means for opening said contact upon an automatic application of the brakes,. a manually operable switch on the train, an acknowledging relay on the train controlled by said normally closed contact and by said manually operable switch as well as by said first and second relays, and a circuit for said brake magnet controlled by said manually operable switch and by said acknowledging relay.

l. Railway traffic controlling apparatus comprising a first train carried relay, means controlled by currents supplied to the track rails for at times energizing said first relay, a second normally energized train carried relay, means controlled by devices located at intervals along the trackway for at times deenergizing said second relay, a normally energized brake controlling magnet on the train effective to apply the brakes after said magnet has been deenergized for agiven in terval of time, means "for deenergizing. said magnet when either of said relays becomes deenergized, a normally closed contact on the train, means for opening said contact upon an automatic application of the brakes, and manually operable means on the train controlled in part by said contact for at times reenergizing said magnet.

5. Railway trailic controlling apparatus comprising, a first train carried relay, means controlled by currents supplied to the track rails for at times energizing said first relay, a second normally energized train carried relay, means controlled by devices located at intervals along the trackway for at times deenergizing said second relay, a normally energized brake controlling magnet on the train eilective to apply the brakes after said magnet has been deenergized for a given interval of time, means for deenergizing said magnet when either of said relays becomes deenergized, a normally closed contact'on the: train, means for opening said contact upon an automatic application of the brakes, manually operable means on the train controlled in part by said contact for at times reenergizing said magnet, andother manually op erable means for at other times reenergizing said magnet.

6. Railway traiiic controlling apparatus comprising a first train carried relay, means controlled by currents supplied to the track rails for at times energizing said first relay, a ccond normally energized train carried relay, means controlled by devices located at intervals along the trackway for at times deenergizing said second relay, a brake controlling magnet on the train effective to apply the brakes after the magnet has been deenergized tor a given interval of time, means for deenergizing said magnet when either said first or said second relay becomes deenergized, a normally closed contact on the train, means for opening said contact upon an automatic application of the brakes, an. acknowledging switch on the train, a reset switch on the train, an acknowledging relay on the train, means controlled by said acknowledging switch and said normally closed contact for at times energizing said acknowledging relay when said second relay is energized and said first relay is deenergized, means controlled by said reset switch for at other times energizing said: acknowledging relay when said second relay is energized and said first relayis deenergized, and a circuit for said brake magnet controlled by said acknowledging switch and said reset switch as well as by said first'and second relays and said acknowledging relay.

7. Railway trafiic controlling apparatus comprising a first train carried relay, meanscontrolled by currents supplied to the track rails for at times energizing said first relay, a second normally energized train carried relay, means controlled by devices located at intervals along the trackway for at times deenergizing said second relay, a brake conrolling magnet on the train eiiective to apply the brakes after the magnet has been deenergized for a given interval of time, a normally closed contact on the train, means for opening said contact upon an automatic. application of the brakes, an acknowledging switch on the train, a reset switch on the train, an acknowledging relay on the train, means controlled by said acknowledging switch and said normally closed contact for at times energizing said acknowledging relay when said second relay is energized and said first relay is deenergized, means controlled by said reset switch for at other times energizing said acknowledging relay when said second relay is energized and said first relay is deenergized, and a circuit for said brake magnet controlled by said acknowledging switch and said reset switch as well as by all of said relays.

8. Railway traffic cont-rolling apparatus comprising a first train carried relay which is controlled by currents supplied to the track rails and a second train carried relay which is controlled by devices located at intervals along the trackway, a brake controlling magnet on the train effective to apply the brakes after the magnet has been deenergized for a given interval of time, a normally closed contact on the train, means for opening said contact upon an automatic application of the brakes, an acknowledging relay on the train controlled by said normally closed contact and said acknowledging switch as well as by said first and second relays, and a circuit for said brake magnet controlled by said acknowledging relay and said acknowledging switch.

9. Railway traffic controlling apparatus comprising a first train carried relay which is controlled by current supplied to the track rails and a second train carried relay which is controlled by devi es located at intervals along the trackway, a brake controlling magnet on the train effective to apply the brakes after the magnet has been deenergized for a given interval of time, a normally closed contact on the train, means for opening said contact upon an automatic application of the brakes, an acknowledging switch on the train, an acknowledging relay on the train controlled by said normally closed contact and said acknowledging switch as well as by said first and second relays, a circuit for said brake magnet controlled by said acknowledging switch and said acknowledging relay as well as by said first relay, and indication means on the train controlled by both of said first and second relays.

10. Railway trafiic controlling apparatus comprising a first polarized train carried relay controlled by devices located at intervals along the trackway, a second train carried relay controlled by currents supplied to the track rails, an acknowledging relay on the train, an acknowledging switch on the train having normally closed and normally open contacts, a brake controlling magnet on the train effective to apply the brakes after the magnet has been deenergized for a given interval of time; a first circuit for said brake magnet including a normally closed contact of said acknowledging switch, a back contact of said acknowledging relay, a normal contact of said first relay, and a front contact of said second ,relay; a second circuit for said brake magnet including said normally closed contact of said acknowledging switch, and a front contact of said acknowledging relay; a pick-up circuit for said acknowledging relay including a normally open contact of said acknowledging switch, a normal contact of said first relay, and a back contact of said second relay; and a stick circuit for said acknowledging relay including a normally closed contact of said acknowledging switch, a normal contact of said first relay, a back contact of said second relay, and a front contact of said acknowledging relay.

11. Railway traffic controlling apparatus comprising a first polarized train carried relay controlled by devices located at intervals along the trackway, a second train carried relay controlled by currents supplied to the track rails, a train carried acknowledging relay, an acknowledging switch on the train having normally closed and normally open contacts, a brake controlling magnet on the train effective to apply the brakes after the magnet has been deenergized for a given interval of time; a first circuit for said brake magnet including a normally closed contact of said acknowledging switch, a back contact of said acknowledging relay, a normal contact of said first relay, and a front contact of said second relay; a second circuit for said brake magnet including said normally closed contact of said acknowledging switch, and a front contact of said acknowledging relay, a pick-up circuit for said acknowledging relay including a normally open contact of said acknowledging switch, a contact which becomes opened upon an automatic application of the brakes, a normal contact of said first relay, and a back contact of said second relay; and a stick circuit for said acknowledging relay including a normally closed contact of said acknowledging switch, a normal contact of said first relay, a back contactof said second relay, and a front contact of said acknowledging relay.

12. Railway traffic controlling apparatus comprising a first polarized train carried relay controlled by devices located at intervals along the trackway, a second train carried relay controlled by currents supplied to the track rails, a train carried acknowledging relay, an acknowledging switch on the train having normally closed and normally open contacts, a brake controlling magnet on the train effective to apply the brakes after the magnet has been deenergized for a given interval of time; a first circuit for said brake magnet including a normally closed contact of said acknowledging switch, a normal contact of said first relay, a front contact of said second relay, and a back contact of said acknowledging relay; a second circuit for said brake magnet including a front contact of said acknowledging relay and a normally closed contact of said acknowledging switch; a pick-up circuit for said acknowledging relay including a normally open contact of said acknowledging switch, a normal contact of said first relay, and a back contact of said second relay; a stick circuit for said acknowledging relay including a normally closed contact of said acknowledging switch, a normal contact of said first relay, a back contact of said second relay, and a front contact of said acknowledging relay, a first and a second lamp on the train, a circuit for said first lamp including a normal contact of said first relay and a back contact of said second rela and a circuit for said second lamp inclu ing a normal contact of said first relay and a front contact of said second relay.

13. Train carried trailic governing apparatus comprising a first train carried receiver core arranged for magnetic coactionwith a trackway inductor and provided with a primary and a secondary winding, a first polarized relay, an acknowledging switch having normally closed and normally open contacts, and a source of current; a main circuit for said primary winding extending from one terminal of said source through a normally closed contact of said acknowledging switch, and said primary winding to the other terminal of said source; a circuit for said secondary winding extending from one terminal of said source through a normally closed acknowledging switch contact, a normal contact of said first relay, the winding of said first relay, said secondary winding, and a portion of said primary winding to the other terminal of said source; an acknowledging circuit for said first relay extending from one terminal of the source through a normally open contact of said acknowledging switch, the winding of said first relay, said secondary winding, and saidportion of said primary winding to the other terminal of said source, said acknowledging circuit being provided with a branch which passes from the one terminal of said source through a resistance and the remainder of said primary to said portion of said primary; a second relay controlled by currents supplied to the track rails, an acknowledging relay, a brake controlling magnet efiective to apply the brakesafter the magnet has been deenergized for a given interval of time, a normally closed contact which becomes opened upon an automatic application of the brakes, an acknowledging circuit for said acknowledging relay extending from one terminal ofsaid source through a normally open contact of said acknowledging switch, a normalcontact of said first relay, a back contact of said second relay, the winding of said acknowledging relay, and said normally closed contact which becomes opened upon an automatic application of the brakes to the other terminal of said source, a stick circuit for said acknowledging relay extending from one terminal of said source through a normally closed contact of said acknowledging switch, a normal contact of said first relay, a back contact ofsaid second relay, and a front contact of said acknowledging relay to the other terminal of said source a first circuit for said brake magnet extending fromone terminal of said source through a normally closed contact of said acknowledging switch, a normal contact of said first relay, a front contact of said second relay, a back contact of said acknowledging relay, and

minal of-said source; and a second circuit for said magnet extending from one terminal of said source through a front contact of said acknowledging relay, and the winding of said magnet to the other terminal of said source.

14. Train carried tr'aific governing apparatus comprising a receiver core arranged for magnetic coaction with a trackway inductor and provided with aprimarv and a secondary win ding, a polarized relay provided with normal contacts, an acknowledging and a reset switch each provided with normally open and normally closedcontacts, and a source of ourrent; a main circuit for said primary winding extending from said source through a -normally closed contact of said'ac'knowledging switch, a normally closed contact of said reset switch, and said primary winding to the other terminal ofsaidsource; a normal circuit for said secondary winding extending from one terminal ofsaid source through a normally closed contact of said acknowledging switch, a normally closed contact of said reset switch, a normal contact of said polarized relay, the

winding of said polarized relay, said secondary winding, and a first portion of said primary winding to the other terminal of said source; an acknowledging circuit for said polarized relay extending from one terminal of said source through a normally opencontact of said acknowledging switch, the winding of said polarized relay, said secondary winding, and said first portion of said primary winding to the other terminal of said source said acknowledging circuit being provided with a branch which passes from said one terminal of said source through a resistance-element, and the remaining portion of the primary winding'to said first portion of said-primary winding; a reset circuit for said polarized relay extending from one terminal of said source through a normally closed contact of said acknowledging switch, a normally open contact of said reset switch, the winding of said polarized relay, said secondary winding, and said first portion of said primary winding to the other terminal of said source; said reset circuit'being providedwith a branch which passes from the said one terminal of said source through saidresistance element, and said remaining portion of said primary winding to said first portion of said primary winding; a brake controlling magnet effective to apply the brakes after the magnet has been deenergized for a given interval of time, a pneumaticrelay arranged to be operated upon anautomatic application of the brakes and provided with a normally closed contact which becomes opened upon an automatic application ofthebrakes, a second relay the winding of said magnet to the other ter- 7 I controlled by currents supplied to thetrack rails, an acknowledging-relay; an acknowledging circuit for said acknowledging relay extending from one terminal of the source through a normally open contact of said a'cknowledging switch, a normal contact ofsaid polarized relay, a back contact of saidsecond vrelay, the normally closed contact of said pneumatic relay, and the winding of said acknowledging relay to the other terminal of said source; a reset circuit for said acknowledging relay extending from said one terminal of said source through a normally closed contact of said acknowledging switch, a normally open contact of said reset switch, a normal contact of said polarized relay, a back contact of said second relay, and the winding of said acknowledging relay to the other terminal of said source; a stick circuit for said acknowledging relay extending from one terminal of said source through a'normally closed contact of said. acknowledging switch, a normally closed contact of said reset switch, a normal contact of said polarizedrelay, a back contact of said second relay, a front contact of said acknowledging relay, and the winding of said acknowledging relay to the other terminal of said source; a first circuit for said brake'controlling magnet extending from one terminal of said source, through a normally closed contact of said acknowledging switch, a normally closed contact of said reset switch, a normal contact of said polarized relay, a front contactof said second relay, a back contact of said acknowledging relay, and the winding'of said magnet to the other terminal of said source: a second circuit for said brake magnet extending from said one terminal of said source through a front contact of said acknowledging relay,- a normally closed contact of said acknowledg ing switch, a normally closed contact of said reset switch, and the winding of said brake magnet to the other terminal of said source; two electric lamps; a circuit for-one'of said lamps extendingfrom one terminal of said source through a normally closed contact of said acknowledging switch, a normally'closed contact of said reset switch, a normal. contact of said polarized relay, a front contactof said second relay, and the filament of said one lamp to the other terminal of said source; and a circuit for'the other of said lamps extending from one terminal of said source through a normally closed contact of saidacknowledging switch, a normally closed contact of said resetswitch, a normal contact of said polarized relay, a back contact of said second relay, and the filament of said second lamp to the other terminal of said source. 7

15. Train carried trafiic governing apparatus comprising a receiver core arranged for magnetic coact-ion with a trackway inductor and provided with a primary and a secondary wlnding, a polarized relay provided with fromone terminal of said front contact of normal contacts, an'acknowle'dging and a reset switch each provided with normally open and normally closed contacts, and a source of current; a main c1rcu1t for said primary winding extending from one ter minal of said source-through a resistance element, a ballast lamp, and said primary winding to the other terminal of said source; a circuit for said secondary winding extending from one terminal of said source through a normal contact of said polarized relay, said' secondary winding, the winding of said polarized'relay, said ballast lamp, and said primary winding to the other terminal of said source; an'acknowledging circuit for said polarizedrelay extending from one terminal of said source through a normally open contact of said acknowledging switch, the winding of said polarized relay, said ballast lamp, and said primary winding to the other terminal of said source; areset'circuit from said polarizedrelay extending from one terminalof said source through a first normally open contact of said reset switch, the winding of said polarized relay, said ballast lamp, and said primary winding to the other terminal of said source; a brake controlling magnet effectiveto apply the brakes after the magnet has been deenergized for a given interval of time, a pneumatic relay arranged to be operated upon an automatic application of the brakes .andprovided with a normally closed contact which becomes opened upon an automatic application of the "brakes, a second relay controlled by currents supplied to the track rails, an acknowledging relay; an acknowledging circuit for said acknowledging relay extending from one terminal of the source through a normalconcuit for said acknowledging relay extending from .one'terminal of said source through a normal contact of said polarized relay, a back contact of said second relay, a front contact of said acknowledging relay, and the winding of said acknowledging relay; a first circuit for said brake controlling magnet extending source through a polarized relay, a said second relay, a back contact of said acknowledging relay, a normally closed contact-of said reset switch, a normally closed contact of said acknowledgnormal-contact of said ing switch, and the winding of said magnet to the other terminal of said source; a second circuit for said brake magnet extending from said one terminal of said source through a front contact of said acknowledging relay, a normally closed contact of said reset switch, a normally closed contact of said acknowledging switch, and the winding of said brake magnet to the other terminal of said source; two electric lamps, a circuit for one of said lamps extending from one terminal of said source through a normal contact of said polarized relay, a front contact of said second relay, and the filament of said one lamp to the other terminal of said source; and a circuit for the other of said lamps extending from one terminal of said source through a normal contact of said. polarized relay, a back contact of said second relay, and the filament of said second lamp to the other terminal of said source.

In testimony whereof I afiix my signature.

ROY E. BAKER.