US2117128A - Railway traffic controlling apparatus - Google Patents

Description

May 10, 1938. YOUNG 2,117,128

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec. 16, 1936 2 Sheets-Sheet 1 55 0 55 IS 4 4 Z 2 c i 1 r'""4'1 %'55 {@m i I i t2 5 E E I ll l v IAIU I l I INV TOR Hen! 06mg.

HIS ATTORN EY May 10, 1938. H. s. YOUNG RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec, 16, 1936 2 SheetsSheet 2 w m 9 H HIS ATTORNEY Patented May 10, 1938 UNITED STATES PATENT OFFICE RAILWAY TRAFFIC CONTROLLING APPARATUS Application December 16, 1936, Serial No. 116,145

13 Claims.

My invention relates to railway trafilc controlling apparatus and particularly to apparatus of the type comprising a trackway device, here shown as a trip, Which is capable of assuming two positions, one of which I will term the operative and the other the inoperative position. The trip is preferably moved to its operative position by a spring or by gravity, or by both, and to its inoperative position by suitable power or energy controlled by trafiic conditions adjacent the trip.

A function of the trackway device is to so control train carried governing means, that such means will be effective for shutting off the propelling power or applying the brakes, or both, of a railway train, should such train pass the trackway device when the latter is in its operative condition.

This is generally accomplished by locating the trip adjacent the track and in the path of an arm carried by the train, which arm operates apparatus for affecting the power or brake systems,

or both, of the train.

It is customary to equip all the cars of a train with arms adapted to engage with the trip when said trip is in the operative position and the train is passing over it, and consequently a train of several cars may be stopped by the arm on any car engaging with the trip. However, it is the usual practice toso locate and control the trip as to cause it to move to its inoperative position immediately after the train enters the track section associated with the trip so that only the arm on the first car of the train will be engaged by the trip.

This control of the trip so that it is released 5 when a train enters the track section with which the trip is associated is necessary in order to cause the trip to assume its inoperative position when trains are operated in the track stretch in the direction opposite to that in which traiiic normally moves.

One object of my invention is to so control the movement of a trip that it will not move to its inoperative position immediately after the train enters the track section associated with the trip,

but will be delayed for a measured interval of time so that, in the event the arm on the first car fails to stop the train, the trip will be effective for engaging the successive arms on the other cars of the train as such arms may pass over the trip.

Other objects of my invention will become apparent as the specification progresses.

My invention provides a positive means for stopping a multiple car train passing over a trip in the operative position, because, if for any reason the arm on the first car of the train should fail to become completely effective for bringing the train to a stop, the arms on one or more of the successive cars of the train may be actuated by the trip.

While I have so far described my invention as 5 being particularly eifeotive' for controlling the movement of multiple car trains, it is evident that my invention will also be effective for controlling the movement of a single car, if such car is equipped with two or more arms spaced longitudi- 10 nally on the car.

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

In the accompanying drawings, Fig. l is a dia- 15 grammatic view illustrating one form of apparatus embodying my invention. Figs. 2 and 3 are diagrammatic views illustrating modifications of a portion of the apparatus shown in Fig. 1, and each also embodying my invention.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Fig. 1, the reference character Z designates a stretch of railway track along which traffic moves normally in the direction indicated by the arrow. The rails 2 and 2A of stretch Z are divided by insulated joints 4, to form three track sections AB, BC, and C-D. Section AB is provided with a signal designated by the reference character 5, and likewise sec- 30 tions BC and C-D are provided with signals designated by the reference characters 3 and I, respectively. Each of the sections is provided With a track relay, designated by the reference character T with a prefix the same as the reference character of the associated signal, connected across rails 2 and 2A adjacent the entrance end of the section. Each section is also provided with a track battery 6 which is connected across rails 2 and 2A adjacent the leaving end of such section.

A trackway trip designated by the reference character S with a prefix the same as the reference character of the associated signal is located adjacent and to the rear of the entrance end of each section AB, BC, and C-D. Trip 3S operates contacts 1, 8, 9, and I0, and trip IS operates contact I l, in accordance with the position of the respective trips, by any usual an well-known means. 50

The contact 1, as is usual and customary in apparatus of this type, is arranged so that it is closed in the inoperative position of the trip 35 and so that it remains closed until the trip is moved substantially to its operative position. 55

Similarly the contacts 8 and 9 are arranged so that they are closed in the operative position of the trip 3S and so that they remain closed until the trip is moved substantially to its inoperative position. The contact I0 is arranged so that it is closed only when the trip is in its inoperative position.

Associated with each signal is a home relay and a distant relay, designated by the reference characters H and J, respectively, each with a prefix the same as the reference character of the associated signal.

Associated with trip 38 is a time controlled mechanism designated by the reference character 3P. This mechanism is here shown as a thermal relay, which, when deenergized, assumes what I will term its initial position, and which when energized assumes, upon the expiration of a measured time interval, what I will term its operated position.

Also associated with trip SS is a manually operable device, designated by the reference character 3PB, and here shown as a push button. The function of push button 3PB is to provide an emergency means for clearing trip 3S by the motorman of a train occupying section AB when it is desired that such train shall enter section BC with trip 3S in its operative condition. The button 3PB is located adjacent the trip and requires the train being brought to a stop before the button may be actuated. This obviously insures that a motorman in so passing trip 3S shall be in full possession of his normal faculties and, therefore, involves no sacrifice in safety.

As here shown, the signals I, 3, and 5, each include a lamp G capable of displaying a green light to indicate proceed, a lamp Y capable of displaying a yellow light to indicate caution, and a lamp R capable of displaying a red light to indicate stop.

The train carried governing means, which I have hereinbefore termed an arm, and with which the trackway device or trip cooperates, is well-known and is, therefore, not shown in the drawing.

In each of the figures I have shown all the circuits which enter into the control for trip 38 and signal 3. Exactly similar circuits and apparatus, both as to design and as to operation, are to be understood as being used for the control of the other trips and signals and associated apparatus. I will, therefore, describe only the circuits and operation for trip 38 and signal 3, as the operation of the other trips and signals will be readily understood from the description of trip 38 and associated apparatus. For the sake of simplicity, I have shown only such portions of the circuits and apparatus at signals I and 5 as are necessary for this description.

Home relay 3H is provided with a control circuit which passes from terminal X of a suitable source of current through front contact I9 of track relay IT, front contact I8 of track relay 3T, and relay 3H to terminal 0 of the same source of current. Thus, relay 3H will be released when either section BC or section CD 1s occupied by a train.

Trip 3S is provided with four clearing circuits. The first clearing circuit passes from terminal X through front contact I2 of relay 3H, and trip 3S to terminal 0. The second clearing circuit includes back contact I3 of relay 3T and front contact I4 of thermal relay 3P; The third clearing circuit includes back point of contact I5 of relay 3T and contact Iii of push button 3P3. The fourth circuit includes back point of contact I? of relay 5T, front point of contact I5 of relay 3T, and contact IB of push button 3PB. Trip 38 is provided with two stick circuits each of which includes trip contact I. The first stick circuit also includes back point of contact I5 of relay 3T and the second stick circuit includes the front point of contact I5 of relay 3T as well as the back point of contact I! of relay 5T.

It is evident from the description of the circuits that trip 3S will be caused to move to its inoperative position when relay 3H is energized, or when thermal relay 3P is in its operated condition and relay 3T is released, or if button 3PB is actuated when either relay 5T or relay 3T is deenergized, and that when trip 3S is in its inoperative position, it will be maintained in such position by the deenergization of either relay 5T or relay 3T. Trip 3S may be caused to move to its operative position when relay 3H is released provided relay 5T and relay 3T is each energized, that is, if section AB and BC is each unoccupied, trip 38 will assume its operative position when section CD is occupied.

Thermal relay SP is provided with a circuit which includes trip contact 3, which is open only when the trip occupies its inoperative position, and back contact I3 of relay 3T. Therefore, thermal relay 3P will be energized if section BC becomes occupied when trip 38 is in its operative position. When relay 3P completes its operation and contact I4 becomes closed, trip 38 will be caused to assume its inoperative position.

Relay 3J is provided with a circuit which includes front contact 20 of relay 3H, front contact 2| of relay 3T, front contact 22 of relay IT, normally closed trip contact II of trip IS, and front contact 23 of relay IH.

The stop lamp R is provided with two circuits one of which includes the back point of contact 24 .of relay 3H, and the other includes the front point of contact 24 of relay 3H as well as trip contact 9 of trip 38. The caution lamp Y and the proceed lamp G are provided with circuits each of which passes through front point of contact 24 of relay 3H and trip contact I0, and thence through back point of contact 25 of relay 3.1 for lamp Y, and front point of contact 25 of relay 3J for lamp G.

From the foregoing description it is apparent that, when the trip 35 is in its inoperative position and relay 3H is energized, signal 3 will display the proceed indication or the caution indication according as relay 3J is energized or deenergized, respectively. The stop indication will be displayed if relay 3H is deenergized or if trip 38 is in its operative position.

Having thus described in general the various parts of Fig. 1, I will now explain their operation.

With all apparatus in its normal condition as shown in the drawings, I shall first assume that a first train traveling in the direction indicated by the arrow enters section AB and proceeds through section BC into section CD. As has previously been described, trip 3S will be maintained in its inoperative position by the closing of back point of contact I! of relay 5T, and by the closing of back point of contact I5 of relay 3T while the train occupies sections AB and BC, respectively, but will be caused to move to its operative position when the train clears section BC because front contact I2 of relay 3H and the back point of contact I5 of relay 3T and the back point of contact I! of relay 5T is each now opened. On this movement of the trip from its inoperative to its operative position, the contacts I and I are opened, while the contacts 8 and 9 are closed.

I shall next assume that a second train traveling in the same direction enters section A--B and, upon approaching signal 3, finds signal 3 displaying the stop indication and trip 38 in its operative position. The motorman may, by bringing his train to a stop and actuating button 3PB, cause trip 3S to move to its inoperative position so that the train may proceed past trip 38 without engaging the train carried arms. The circuit for supplying current to the trip 38 by operation of push button 3PB is traced from the terminal X at signal 5, through back point of contact I! of relay 5T which is released at this time because of the presence of the train in section A-B, front point of contact I5 of relay 3T which is picked up at this time as the train in advance has vacated section BC, and push button I6 to trip 35. If, however, the second train attempts to move past trip 3S without the button 3PB being actuated, such as may happen, for example, if, while approaching signal 3, the motorman suffered a temporary loss of his normal faculties, trip 38 will immediately engage the arm on the first car to cause the train to come to a stop. The trip will continue to engage the arms on the successive cars as long as such arms pass over the trip in its operative position. Trip 38 will not move to its inoperative position immediately upon entrance of the train into the track section BC but will remain in its operative position until front contact I4 of relay 3P becomes closed, which relay became energized by the closing of back contact I 3 of relay 3T upon the occupancy of section BC by the second train. The operating characteristics of the relay 3P are such that the contact I4 does not become closed until after the expiration of a predetermined time interval after the supply of current to the relay is initiated by the closing of contact I3 of relay 3T. Accordingly the trip 38 will not be caused to move to its inoperative position for a predetermined time interval after the forward portion of the train passes over the trip. In the event that the train carried arm on the first car of the train should fail to become effective for stopping the train, it is readily apparent that, depending upon the speed of the train, one or more of the successive train carried arms may pass over the trip before such trip assumes its inoperative condition.

As soon as the trip 38 moves to its inoperative position, contact 8 will become opened and energy will be disconnected from thermal relay 3P which will then cool and return to its initial condition. After the opening of contact I4 of relay 3P trip 3S will be maintained in its inoperative condition by the closing of trip contact I which established a stick circuit for trip 38 through back point of contact I5 of relay 3T.

The pickup time of thermal relay 3P may be varied by means well-known to those skilled in the art so the proper delay time for the clearing of trip 38 may be provided in accordance with traffic conditions. The minimum delay time should preferably be such that, if the arm of the first car of a train, moving above a predetermined speed, should fail to become effective for stopping the train, the trip will be certain to engage with at least the next successive arm. The maximum delay time should preferably be such that, in the event a train moving at normal speed against the current of traffic enters the section A-B at the right-hand end, the trip 38 will be caused to assume its inoperative position before the train reaches the trip.

While I have not described the operation of the trip 33 and associated apparatus for a train moving against the normal direction of traffic, it is evident that such a train upon entering section BC from section C-D at a time when the trip 38 is in its inoperative position will release relay 3T which will close its back contact I3 to complete the circuit for the energization of relay 3P. Relay 3P, upon attaining its operated condition, will establish a clearing circuit for trip 38. It will be seen, therefore, that ordinarily the arms carried on a train traveling against the normal direction of traffic will not be engaged by trip 38.

Referring now to Fig. 2, the arrangement illustrated herein is similar to that shown in Fig. 1, except that the thermal relay 3P and the distant relay SJ have been replaced by and their functions combined in, one relay designated by the reference character EJA. The relay HJA is of the slow pickup type, which is well-known and which needs no detailed description.

The trip 38 is provided with four clearing circuits. The first circuit includes front contact I2 of relay SE. The second circuit includes back point of contact I5 of relay ET and contact I6 of push button 3PB. The third circuit includes back point of contact ll of relay 5T, front point of contact I5 of relay 3T, and contact I6 of push button 3PB. The fourth clearing circuit includes back point of contact I5 of relay 3T, front contact I 4A of relay 3JA, and back contact 26 of relay 3T. Trip 36 is provided with two stick circuits each of which includes contact I which is closed when the trip occupies its inoperative position. The first stick circuit also includes back point of contact I5 of relay 3T, and the second stick circuit includes the front point of contact 55 of relay 31' as well as the back point of contact I! of relay 5T.

Thus it will be seen that the circuits for trip 38 illustrated in Fig. 2 cause trip 3S to operate in a manner similar to that previously described for the apparatus shown in Fig. 1.

The slow pickup relay 3JA is provided with two control circuits. The first control circuit includes front point of contact 20 of relay 3H, front point of contact H of relay 3T, front contact 22 of relay IT, trip contact I I of trip IS, and front contact 23 of relay IH. The second control circuit includes back point of contact 20 of relay 3H, back contact I3 of relay 3T, and trip contact 8. In other words, when relay 3His energized, relay 3JA is controlled by relays IH,

, IT and trip IS and, therefore, functions as a distant relay, but when relay 31-1 is deenergized, relay SJA is controlled by relay ST and trip 38 and, therefore, functions as a timing relay for the clearing of trip 38.

The home relay 3H is provided with a circuit identical to and functioning in the same manner as described for relay 3H shown in Fig. 1.

The stop lamp R, caution lamp Y, and proceed lamp G for signal 3 are provided with the same control circuits and the same indication is dis played for the same trafiic conditions as described for signal 3 shown in Fig. l.

The operation of the modification of my invention illustrated in Fig. 2 is as follows:

I shall first assume that a first train traveling in the direction indicated by the arrow has proceeded through sections AB and BC and is now in section C-D. Signal 3 will be displaying the stop indication and strip 3S will be in its operative condition. Relay 3H will be deenergized because relay IT is released and relay 3JA will be deenergized because relay 31-1 is released and relay 3T is picked up. Under these conditions, I shall next assume that a second train traveling in the same direction attempts to pass trip 38 and enter section BC. The trip- 38 will actuate the arm on the first car of the second train and will continue to actuate the arms on the successive cars as long as the trip remains in its operative condition and such arms continue to pass over the trip. When the second train enters section B-C, relay 3T will become released which will complete a circuit for relay 3JA through trip contact 8 closed when trip 3S is in its operative condition, back contact l3 of relay 3T and back point of contact 20 of relay 3H. Upon the expiration of a measured time interval relay 3JA will close its front contact MA to complete a clearing circuit for trip 38 from terminal X through back point of contact I5 of relay 3T, contact MA, and back contact 26 of relay 3T. It will be seen, therefore, that on entrance of a train into the block section B-C and the release of relay 3T a clearing circuit for the trip 38 will be established, but only after a time interval determined by the pick-up time of relay 3JA. This time interval is long enough to insure that the arm on more than one car will be engaged by the trip before the trip is caused to move to its inoperative position.

As soon as trip 38 moves to its inoperative position, contact 8 will become opened and energy will be disconnected from relay 3JA which will then be released. Thip 3S will, however, be maintained in its inoperative condition by a stick circuit completed by the reclosing of trip contact I. This stick circuit is traced from terminal X through back contact I5 of relay 3T and trip contact I.

I shall now assume that the first train has proceeded a sufficient distance so that the second train may enter and proceed through section C--D into the next section in advance, not shown in the drawings. When the second train vacates section CD relay 3H will become energized when relay IT picks up, but relay 3JA will remain deenergized because relay II-I is deenergized and contact II of trip- IS is opened. Signal 3 will, therefore, display the caution indication. The proceed indication will be displayed by signal 3 when the second train has proceeded a distance sufficient to cause signal I to display the caution indication.

From the foregoing description, it will be seen that in the system shown in Fig. 2 I have provided a single relay 3JA which at times provides the proceed and caution indications for the signal with which it is associated, and which, at other times, acts in a manner similar to that described for relay 3? for delaying the clearing of the trackway trip 3S.

Trip 35, as controlled by the circuits and appa ratus shown in Fig. 2, will assume its inoperative position when a train traveling against the normal direction of traffic enters section BC, in a manner similar to that described for a train traveling in the normal direction.

Thus it will be seen that when a train traveling from left to right enters block section CD, the relay IT is released, thereby reopening contact I9 and deenergizing relay 3H with the result that contact I2 of relay 3H becomes opened and interrupts the supply of current to the trip 3S which thereupon moves to the operative position.

In addition, upon the release of relay 3H the contact 20 is released and. engages its back point of contact. However, at this time the relay ST is energized and its contact I3 is picked up so the release of contact 20 of relay 3H will not affect the supply of current to relay 3JA.

When the train enters section B-C the track relay ST is released, thereby establishing a circuit for supplying current to relay 3JA. This circuit is traced from terminal X through trip contact 8 which is closed in the operative position of the trip, back point of contact I3 of relay 3T, and back point of contact 20 of relay 3H. The relay 3JA will become picked up after a short time interval, and its contact I4A will establish a circuit for supplying current to the trip 3S, this circuit being traced from terminal X, through back point of contact I5 of relay 3T, front point of contact IA of relay 3JA, and back point of contact 26 of relay 3T to trip 38. The pick-up time of relay 3JA is such that this relay will become picked up and energize the clearing circuit for the trip 3S to cause the trip to move to its inoperative position before the train reaches the trip.

Referring now to Fig. 3, the relay 3P is again employed, as will be explained hereinafter, for providing a delay time in the clearing of the trip 38. It will be noted that trip 3S is located somewhat in advance of signal 3 instead of in rear of the signal, and that no push button has been provided for emergency clearing of the trip. With the trip located slightly in advance of the signal, no manual emergency means is required for causing the trip to assume its inoperative position because the trip is so located as to permit the entrance end of section B-C being occupied by at least the front truck of the train without the train carried arm being en gaged by the trackway trip. Thus, a motorman by bringing his train to a stop in the entrance end of section B--C, may cause trip 3S to assume its inoperative position after the expiration of a measured time interval, thereby permitting the train to pass over the trip without an actuation of the train carried arms. This arrangement 0bviously involves no sacrifice in safety, since the train, before being permitted to pass a trip in its operative condition, must be brought to a stop and must then wait a predetermined time interval before proceeding.

Trip 3S is provided with the usual contacts I, 8, 9, and I0, and, in addition, is provided with contacts 21 and 28 each operated by and assuming a position corresponding to the position of trip 3S. The contact 21, like the contacts 8 and 9, is arranged so that it is open when the trip is in its inoperative position, and is closed when the trip is in its operative position. Similarly the contact 28, like the contacts "I and II], is arranged so that it is open when the trip is in its operative position, and is closed when the trip is in its inoperative position. The function of trip contact 28 in the control circuit for relay 5J is the same as the function of contact II of trip IS in the control circuit for relay 3J and requires no further explanation. The function of contact 21' will be explained hereinafter.

I have provided trip 3S with two pickup circuits and one stick circuit. The first pickup circuit includes front contact I2 of relay 3H, and. the second pickup circuit includes back contact I3 of relay ST and front contact I4 of relay 3P.

a stick circuit.

The stick circuit includes back contact [3 of relay 3T and trip contact 1 which is open only when trip 38 is in its operative condition. It is evident from the circuits that trip 3S will be caused to move to its inoperative position when relay 3H is energized or when relay 3T is deenergized and relay 3P is in its operated condition, and that, when trip 35 is in its inoperative position it will be held in such position by the releasing of relay 3T. Trip 38 may be caused to move to its operative position when relay 3H is deenergized provided relay 3T is energized; that is, if section BC is unoccupied, trip 38 will assume its operative position when section C-D is occupied.

Thermal relay 3P is provided with a circuit which includes trip contact 8 and back contact 13 of relay 3T, so that relay 3P will be energized by the occupancy of section B- C if the trip 33 is in its operative position.

Relay 3H is provided with a pickup circuit and The pickup circuit includes front contact IQ of relay IT, front contact H! of relay 3T, and trip contact 2! closed when trip 3S is in its operative position. The stick circuit includes its own front contact 29 and front contacts [8 and IQ of relays 3T and IT, respectively. It is apparent that relay 3H will be deenergized when either section B-C or C- D is occupied, and when released may again be energized if and only if trip 38 assumes its operative position and section B-C and C-D is each clear, thus providing a means for causing signal 3 to display continuously the stop indication in the event trip 33 fails to assume its operative condition upon the occupancy of section C-D.

The operation of the modification of my invention shown in Fig. 3 is as follows: I shall first assume that a first train traveling in the direction indicated by the arrow has proceeded through sections A-B and B-C and is now in section C-D. Signal 3 will be displaying the stop indication and trip 38 will be in its operative position.

I shall next assume that a second train traveling in the same direction enters section A-B and, upon approaching signal 3, finds signal 3 displaying the stop indication and trip 38 in its operative position. If the motorman is alert and in possession of his normal faculties, he may, by entering section B and bringing his train to a stop before passing over trip 3S, cause the trip to move to its inoperative position. If, however, the motorman attempts to pass trip 3S without stopping, the train carried arm on the first car will engage with the trackway trip and the arms on the successive cars will also engage with the trip as long as such arms continue to pass over the trip and the trip remains in the operative position. When the train enters section B-C, back contact l3 of relay 3T will be-' come closed to complete, through trip contact 8, the circuit for energizing relay 3P. As soon as relay 3P completes its operation so that front contact l4 becomes closed, trip 38 will be caused to move to its inoperative position because one of its clearing circuits, including back contact I 3 of relay 3T and contact [4 of relay 3P, will then be closed. When trip 38 moves to its inoperative position, trip contact 8 will become opened which will remove energy from thermal relay 3P so that relay 3]? will return to its initial condition. As soon as the trip 38 moves away from the operative position a holding circuit for trip 38 is established through trip contact 7 and back cohtact I3 of relay 3T so that trip 35 will be maintained in its inoperative position as long as section B-C is occupied.

When the second train enters section C--D and clears section B-C, the stick circuit for trip 38 will be broken by the opening of back contact l3 of relay 3T. At this time as the section B-C is unoccupied relay 3T will be picked up with the result that its contact l3 will interrupt one pickup or clearing circuit for trip 38. In addition, at this time, the relay 31-1 is released with the result that its contact l2 interrupts the other clearing circuit for the trip 33, and since both clearing circuits are now open, trip 38 will again assume its operative position and will remain in that position until such time as relay 3H becomes energized, which will not occur until the train vacates section C-D and relay IT picks up. Trip contact 2'! in the pickup circuit for relay 3H is closed when trip 33 is in its operative position so that relay 3H will become energized as soon as section C-D is unoccupied. When relay 3H becomes energized, trip 38 will be energized and caused to move to its inoperative position.

The modification of my invention shown in Fig. 3, therefore, provides a means for delaying the clearing of trip 38 when a train enters section B-C with the trip in its operative position so that, in the event the train carried arm on the first car of the train should fail to become effective for stopping the train, the trip will engage with one or more of the arms on the successive cars of the train.

Trip 3S, as controlled by the circuits and apparatus shown in Fig. 3, will operate, for a train running against the normal direction of trafiic, in a manner similar to that described for the apparatus shown in Fig. 1.

While, for the sake of simplicity, I have omitted, in each figure, certain apparatus associated with signals I and 5 and trackway trips IS and 53, it is understood that such signals and trips will usually be provided with all of the associated apparatus shown for signal 3 and trip 38 and will operate in a manner identical to that described for signal 3 and trip 38.

Although I have herein shown and described only a few forms of 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. In combination, a forward and a rear as well as an intermediate section of railway track each provided with a track circuit including a track relay, a control relay which is energized only if the track relays for the forward and intermediate sections are both energized, a trackway trip for the intermediate section including one contact which is closed when the trip is in its inoperative position and is open when the trip is in its operative position and another contact which is closed when the trip is in its operative position and is open when the trip is in its inoperative position, a slow pickup relay, means for energizing said slow pickup relay when the track relay for the intermediate section is released provided said other contact is closed, a clearing circuit for said trip including a front contact of said control relay, another clearing circuit for said trip including a back contact of the track relay for the intermediate section and a manually operable contact, still another clearing circuit for said trip including a back contact of the track relay for the rear section and a front contact of the track relay for the intermediate section as well as said manually operable contact, still a different clearing circuit for said trip including a back contact of the track relay for the intermediate section and a front contact of said slow pickup relay, a holding circuit for said trip including said one contact and a back contact of the track relay for the intermediate section, and another holding circuit for said trip including said one contact and a front contact of the track relay for the intermediate section as well as a back contact of the track relay for the rear section.

2. In combination, a forward and a rear as well as an intermediate section of railway track each provided with a track circuit including a trackrelay, a control relay which is energized only if the track relays for the forward and intermediate sections are both energized, a trackway trip for the intermediate section including one contact which is closed when the trip is in its inoperative position and is open when the trip is in its operative position and another contact which is closed when the trip is in its operative position and is open when the trip is in its inoperative position, an auxiliary relay having a slow pickup characteristic, means controlled by traffic conditions in the forward section for energizing said auxiliary relay when said control relay is picked up, means including said other contact and a back contact of the track relay for the intermediate section for energizing said auxiliary relay when said control relay is released, manually operable means for energizing said trackway trip when either the track relay for the intermediate section or the track relay for the rear section is released, means controlled, by said auxiliary relay for governing said trackway trip, and a signal for the intermediate section also controlled by said auxiliary relay jointly with said one contact.

3. In combination, a forward and a rear section of railway track each provided with a track circuit including a. track relay, a control relay, means including a front contact of the track relay for the forward section as well as a front contact of the track relay for the rear section for energizing said control relay, a trackway trip for the rear section including one contact which is closed when the trip is in its inoperative position and is open when the trip is in its operative position and another contact which is closed when the trip is in its operative position and is open when the trip is in its inoperative position, a normally deenergized thermal relay, means for energizing said thermal relay when the track relay for the rear section is released provided said other contact is closed, a clearing circuit for said trip including a front contact of said control relay, another clearing circuit for said trip including a back contact of the track relay for the rear section and a front contact of said thermal relay, and a holding circuit for said trip including a back contact of the track relay for the rear section and said one contact.

4. In combination, a forward and a rear section of railway track, a trackway trip for the rear section having an operative and inoperative position, a signal for the rear section, a relay, means effective when said relay is picked up to control said trip provided the rear section is then occupied, means effective when said relay is picked up to control said signal provided the rear section is unoccupied and said trip is in its inoperative position, means for controlling said relay when the rear section is occupied provided said trip is in its operative position, and other means for controlling said relay when the forward and rear sections are both unoccupied.

5. In combination, a section of railway track, a trackway device adjacent the entrance to said section, said device normally occupying an inoperative condition but capable of assuming an operative condition to control one or more of a plurality of train carried governing means spaced longitudinally on a train entering said section, means controlled by traffic conditions in advance of said section for at times causing said device to assume its operative condition, timing apparatus, means effective to initiate the operation of said timing apparatus when said section becomes occupied provided said device is then in its operative condition, and means controlled by the timing apparatus for causing said device to assume its inoperative condition when said apparatus completes its operation.

6. In combination, a section of railway track, a trackway device adjacent the entrance to said section, said device normally occupying an inoperative condition but capable of assuming an operative condition to control one or more of a plurality of train carried governing means spaced longitudinally on a train entering said section, means controlled by traffic conditions in advance of said section for at times causing said device to assume its operative condition, timing apparatus, means effective to initiate the operation of said timing apparatus when said section becomes occupied provided said device is then in its operative condition, means controlled by the timing apparatus for causing said device to assume its inoperative condition when said timing apparatus completes its operation, and means then eifective to retain said device in its inoperative condition as long as said section remains occu-.

pied.

7. In combination, a section of railway track provided with a track circuit including a track relay, a trackway device adjacent the entrance to said section, said device normally occupying an inoperative condition but capable of assuming an operative condition to control one or more of a plurality of train carried governing means spaced longitudinally on a train entering said section, means controlled by traflic conditions in advance of said section for at times causing said device to assume its operative condition, an auxiliary relay having a slow pick-up characteristic, means including a back contact of said track relay for energizing said auxiliary relay provided said device is in its operative condition, and means also including a back contact of said track relay for causing said device to assume its inoperative condition when said auxiliary relay is picked up.

8. In combination, a section of railway track, a trackway device adjacent the entrance to said section, said device normally occupying an inoperative condition but capable of assuming an operative condition to control one or more of a plurality of train carried governing means spaced longitudinally on a train entering said section, means controlled by traflic conditions in advance of said section for at times causing said device to assume its operative condition, a contact which is closed when said device is in its operative condition and open when said device is in its inoperative condition, a relay having a slow pick-up characteristic, means including said contact for energizing said relay when said section becomes occupied, and means controlled by the relay for causing said device to assume its inoperative condition when said relay becomes picked up.

9. In combination, a section of railway track, a trackway device adjacent the entrance to said section, said device normally occupying an inoperative condition but capable of assuming an operative condition to control one or more of a plurality of train carried governing means spaced longitudinally on a train entering said section, a signal also adjacent the entrance to said section, a normally energized relay for controlling said signal, said relay having a slow pick-up characteristic, means governed by traific conditions in advance of said section for at times causing said device to assume its operative condition and for causing said relay to become deenergized, means effective to energize said relay when said section becomes occupied provided said device is in its operative condition, and means controlled by the relay for causing said device to assume its inoperative condition when said relay becomes picked up.

10. In combination, a section of railway track, a signal for said section, a home relay for said signal, means controlled in accordance with trafiic conditions in advance of said section for energizing or deenergizing said home relay, a distant relay having a slow pick-up characteristic, means eiiective when and only when said home relay is energized to place said distant relay under control by other traflic conditions in advance of said section and to place said signal under control by said distant relay, a trackway device adjacent the entrance to said'section and normally in an inoperative condition but capable of assuming an operative condition to actuate one or more of a plurality of train carried governing means spaced longitudinally on a train entering said section, means effective when said home relay is deenergized to cause said device to assume its operative condition, means also effective when said home relay is deenergized to supply energy to said distant relay when said section becomes occupied provided said device is then in its operative condition, and means controlled by the distant relay for causing said device to assume its inoperative condition when said distant relay is picked up.

11. In combination, a section of railway track, a signal for said section, a home relay for said signal, means controlled in accordance with trafflc conditions in advance of said section for energizing or deenergizing said home relay, a distant relay having a slow pick-up characteristic, means effective when and only when said home relay is energized to place said distant relay under control by other traflic conditions in advance oi said section and to place said signal under control by said distant relay, a trackway device adjacent the entrance to said section and normally in an inoperative condition but capable of assuming an operative condition to actuate one or more of a plurality of train carried governing means spaced longitudinally on a train entering said section, means effective when said home relay is deenergized to cause said device to assume its operative condition, means including a back contact of said home relay for energizing said distant relay when said section becomes occupied provided said device is then in its operative condition, and means controlled by the distant relay for causing said device to assume its inoperative condition when said distant relay is picked up.

12. In combination, a stretch of railway track divided into a plurality of successive track sections, a trackway device adjacent the entrance to each of said sections, each said device normally occupying an inoperative condition but capable of assuming an operative condition to control one or more of a plurality of train carried governing means spaced longitudinally on a train entering the associated section, means for at times causing each such device to assume its operative condition when a section in advance of the associated section is occupied, timing apparatus for each section, means for each timing apparatus for initiating the operation thereof when the associated section becomes occupied provided the associated device is in its operative condition, and means for causing each such device to assume its inoperative condition when the associated timing apparatus completes its operation.

13. In combination, a stretch of railway track divided into a plurality of successive track sections, a signal for each section, a home relay and a distant relay for each section for controlling the associated signal, each said distant relay having a slow pick-up characteristic, means for each section for energizing or deenergizing the associated home relay in accordance with traflic conditions in advance, means for each section for governing the associated distant relay in accordance with other traffic conditions in advance when and only when the corresponding home relay is energized, a trackway device adjacent the entrance to each section, each said device normally in an inoperative condition but capable of assuming an operative condition to control one or more of a plurality of train carried governing means spaced longitudinally on a train entering the associated section, means for at times causing each device to assume its operative condition when the associated home relay is deenergized, means for energizing each distant relay when the associated section becomes occupied provided the associated device is in its operative condition, and means for causing each device to assume its inoperative condition when the associated distant relay is picked up.

HENRY S. YOUNG.

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