US1750441A - Railway-traffic-controlling apparatus - Google Patents

Description

March 11,, 1930. H. A. THOMPSON 1,750,441

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed May 22, 1926 2 Sheets-Sheet l INVENTOP I w. QDTLM March 11, 1930.

H. A. THOMPSON RAILWAY TRAFFIC CONTROLLING APPARATUS Filed May '22, 1926 2 Sheets-Sheet 2 Patented Mar. 11, 1930 UNITED STATES PATENT OFFICE HOWARD A. THOMPSON, OF EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA RAILWAY-TRAFFIC-CONTROLLING APPARATUS Application filed May 22, 1926. Serial No. 110,922.

My invention relates to railway traflic controlling apparatus, and particularly to the trackway portion of an automatic train control system.

More particularly my invention comprises means for transmitting train control energy and for operating the signals in a three block indicating system without the use of line wires between the signal locations.

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

In the accompanying drawings, Fig. 1 is a diagrammatic view showing one form of trackway apparatus embodying my invention. Fig. 2 is a view of a modification also embodying my invention.

Similar reference characters refer to similar parts in both views.

In Fig. 1, reference characters 1 and 1 designate the track rails of a railroad over which traflic normally moves in the direction indicated by the arrow. These track rails are divided,.by means of insulated joints 2, into a pluralit of successive track sections A-B, B-O, D, etc.

Each track section is provided with a polarized track relay designated by the reference character R with an exponent corresponding to the location and connected across the rails near the entrance end of the section. Current is supplied to the track rails from a suitable source of direct current, such as a battery 4 connected across the track rails near the exit end of the section. A resistor 5 is connected between each battery 4 and one rail of the corresponding track section in the usual manner, and a pole changer 21 and relay contact 29 are included in each track circuit for reasons which will appear hereinafter.

Each section is also provided with a trackway signal designated by the reference character S with an exponent corresponding to the location. These signals may be of any suitable form and are shown as semaphore signals comprising an upper arm 39 capable of indicating stop, caution or proceed, and a lower arm 40 capable of indicating stop or proceed. \Vhen upper arm 39 is in the 45 or caution position and lower arm 40 is in the zero or stop position the signal S indicates proceed, prepared to stop at the next signal which I shall designate an alert indication. When arm 39 is in the 45 position and arm 40 is in the 90 position the signal S indicates proceed, prepared to pass next signal at medium speed which I shall designate a caution indication. Since the position of arm 40 is changed from the zero position only when giving the caution indication, the proceed and stop indications correspond to those used for ordinary single-arm threeposition signals.

The upper arm 39 of each of the trackway signals is controlled through the contacts of two slow-acting relays designated by reference characters K and L with an exponent corresponding to the location, these relays being, in turn, controlled by the neutral contacts of the polarized track relay of the corresponding track section. When, for example, relay B is energized, relay L will also be energized over a circuit from battery G through wire 6, front contact 715 of relay R wire 8, relay L and wire 9 to battery. Energization of relay L closes its front contacts 10 and 11 to complete a caution indication circuit for arm 39 of signal S from battery G through wire 12, front contact 10-10 of relay L wires 20 and 13 operating mechanism for arm 39, wire 14, front contact 11 of relay L and wire 9 to battery.

The lower arm 40 of each signal is controlled through a back contact 4142 of the associated relay K and a polar contact 28 of the associated relay R. The arm 40 can assume the 90 degree position only when both of these contacts are closed. The circuit for the arm 40 is from battery G through wire 12, contact 10-10 of relay L wire 20, polar contact 28 of relay R wire 32, contact 4142 of relay K wire 43, operating mechanism for arm 40 of signal S wire 14, contact 11 of relay L and wire 9 back to battery. It will thus be seen that with relays R and L energized arm 39 of signal S will be in the 45 position and the circuit for relay K will be open at the back contact 7-16 of relay R Contact 4142 of relay K being open, arm 40 will be in the zero or stop position.

The circuit for relay K is from battery G wire 6 back contact 716 of relay R wire 33, relay K and wire 9 back to battery G. If the front contacts of relays K and L are closed simultaneously, current will flow from battery G through wire 12 front contact 1010 of relay L contact 17 of relay K wire 18, operating mechanism of arm 39 of signal S wire 14, front contact 11 of relay L and wire 9 to battery G When this circuit is closed arm 39 is in the 90 or proceed position. WVhen relay L is deenergized the operating circuits for both arms 39 and 40 of signal S are opened and the signal then displays a stop indication.

Each section is provided with means for supplying alternating train controlling current to the track rails. For this purpose I provide a track transformer designated by reference character T with an appropriate exponent having its secondary winding 22 connected in series with the corresponding track battery 4, resistor 5 and pole changer 21. An impedance 23 is connected in circuit between the secondary 22 of each track transformer T and the associated pole changer 21 in the usual manner. Each transformer T is at times supplied with alternating current from an associated line transformer designated by the reference character H with an exponent corresponding to the location. The primary 26 of each line transformer H is constantly supplied with alternating current from a source, such as an alternator X, over line wires 3 and 3.

The primary 24 of each track transformer T is controlled by a polar contact 27 of the adj acent track relay R and also by a front contact 31 of the adjacent relay L. It will thus be seen that de-energization of a slow acting relay such as L will open contact 31 and interrupt the flow of current in primary 24 of the adjacent track transformer T, and hence that train controlling current can never be supplied to the track rails of a sect-ion when polar contact 27 of the track relay R or front contact 31 of the relay L for the section next in advance is opened.

In circuit with polar contact 28 of each track relay R is a coding device which as here shown is a flasher relay designated by the reference character F with an appropriate exponent. The circuit for this relay includes its own front contact 30 so that when energized by closing of polar contact 28 it will pe-' relay F will open contacts 29 and 30 thus deenergizing the relay and opening the circuit of the secondary of track transformer T and track battery 4 until contact 30 falls by gravity to again energize the relay. Alternate opening and closing of contacts 29 and 30 will take place as long as contacts 1010 and 28 remain closed. Assuming the primary 24 of track transformer T C to be closed at contacts 27 and 31, operation of relay F C will cause intermittent alternating train control current and pulsating direct current to be supplied to track section B-O.

Upper arm 39 of each trackway signal controls a pole changer 21 which is in circuit with track battery 4 of the section in rear of the signal. Each pole changer 21 occupies one position when the arm 39 of the associated signal is in the 45 or 90 position and the other position when the arm is in the zero position. When a signal such as S indicates proceed, caution or alert section BC is supplied with track circuit current of one polarity which I shall term normal polarity, and relay B is energized in the normal direction, thus closing polar contacts 27 and 28. When signal S indicates stop, section 13-0 is supplied with track circuit current of the opposite polarity, which I shall term reverse polarity, and relay R is energized in the reverse direction to open contacts 27 and 28 by swinging them to the right. Track circuit current is supplied constantly when contact 29 remains closed due to de-energization of the associated flasher relay F, but when a flasher relay such as F is energized the supply of track circuit current is intermittent and this relay is so timed that relay R will operate its neutral contacts 15 and 16 at such rate that the front contacts controlled by slow acting relays K and L remain closed.

It will now be clear that when a track section such as C-D is supplied with current of reverse polarity the polar contact 28 of the track relay R will be open and the o crating mechanism for arm 40 can never e energized to allow the signal S to indicate caution under these conditions. If the section CD is supplied with current of normal polarity the polar contact 28 remains closed and arm 40 assumes the 90 position when relay K is tie-energized so that its back contact 41-42 closes.

The trackway apparatus herein shown and described may be used with train carried governing means which will give a less restrictive indication, as a proceed indication, when a train occupies a track section which is intermittently supplied with alternating train controlling current, but will give a more restrictive indication, such as a stop indication, when the supplyof train controlling current is suspended.

As shown in the drawing the section at the right of point D is occupied by a train V. Relay R is de-energized and its back neutral contact 716 is therefore closed to complete a circuit for slow acting relay K from battery G through contact 716, wire 33, relay K and wire 9 back to battery. Contact 715 of relay R being open, relay L is de-energized and its front contacts 1010 11 and 31 are opened. Under this condition the signal S indicates stop because the circuits for the operating mechanism are opened at front contacts l()10 and 11 of relay L and back contact 41-42 of relay K Opening of contact 10l0 also cuts off the supply of current to flasher relay F D by breaking the circuit which may be traced from battery G through wire 12, contact 101O of relay L wire 20, contact 28, wire 32, contact 30, relay F and Wire 9 to battery. De-energization of relay F leaves contact 29 closed so that track circuit current of reverse polarity is constantl supplied to track section CD by track battery 4, the pole changer 21 having been placed in reverse position by the signal S going to the stop position. N 0 train controlling current is supplied to section CD because the primary of track trans former T is open at contact 31.

Relay R is energized thus closing neutral contact 15 and energizing relay L so that signal S gives an alert indication. Polar contacts 27 and 28 of relay R are open because section CD is supplied with track circuit current of reverse polarity, hence, the operating circuit for arm 40 is open at 28 and this arm remains in the zero position. No train controlling current is supplied to section BC because polar contact 27 is open.

Flasher relay F is de-energized due to opening of polar contact 28, and hence contact 29 is closed and track circuit current of normal polarity is supplied to section B-C by battery 4.

Relay R is energized to close contact 7-15, and since section BC is supplied with track circuit current of normal polarity contacts 27 and 28 are closed. Relay L is energized and closes the circuit for flasher relay F B which operates to periodically open and close contacts 30 and 29. WVhile flasher relay F is in operation, current is intermittently supplied to track relay R so that this relay is alternately energized and de-energized, with the result that relays L and K are alternately energized. The characteristics of relays L and K are such that the front contacts of each of these relays remain closed during the intervals in which the flasher relay is de-energized while it is in operation. The opening and closing of contact 29 supplies intermittent alternating tram control current to section AB from track transformer T the primary of which remains closed at contacts 27 and 31. Opening and closing of contact 29 also supplies pulsating U1 UILOIHU.

direct current to the section A-B from track battery 4. Contact 10l0 of relay L is closed, but contacts 17 and 41-42 of relay K are open, hence the signal S indicates caution. It is clear, therefore, that this system inherently distinguishes the indications of the two signals in rear of an occupied block, because one of the associated sections is supplied with track circuit current of reverse polarity to open polar contact 28 and thus open the operating circuit for arm 40 of the signal S, while current of normal polarity is supplied to the adjacent section in the rear and since polar contact 28 is therefore closed, the arm 40 will be moved to the position. The flasher relay F is so timed that the front contacts of slow acting relays- K and L remain continuously closed. The signal S indicates proceed so long as relay K holds its contact 17 closed and contact 41-42 open and relay L holds its contact 10l0 closed and cannot so indicate unless this is true. Hence a failure of flasher relay F or a failure of track relay R to keep in step with the periodic currents supplied to it will always cause a more restrictive signal indication. Either condition mentioned will cause either contact 15 or 16 of track relay R to remain closed to de-energize either relay L or K. If relay K is de-energized the signal S will indicate caution or alert depending upon the polarity of the track circuit current supplied to the section and if L is de-energized it will indicate stop.

The signals are controlled in accordance with what is known as three block indication, that is, the two signals next in the rear of a stop signal give a more restrictive indication and the third signal in the rear of a stop signal indicates proceed. For purposes of this application the indications will be designated stop, alert, caution and proceed, respectively.

If, under the conditions shown in Fig. l a second train proceeds through the stretch of track it will receive intermittent train controlling energy as far as point B where the supply will be cut off and no train controlling energy will be received between points B and D.

The apparatus shown in Fig. 1 is designed for use with a train control system in which the locomotive equipment responds to intermittent alternating train control current. The'operation of the flasher relays supplies the track sections simultaneously with pulsating direct track circuit current and intermittent alternating current whenever two sections in advance are unoccupied. If it is desired to use this system in connection with locomotive equipment which is not designed to operate on intermittent alternating train control current, the trackway apparatus may be modified as shown in Fig. 2.

Referring now to Fig. 2 the parts with the exception of the circuits for the track circuit and train control currents are arranged exactly as in Fig. l. The secondary 22 of track transformer T and track battery 4 are here connected in parallel, and only the branch including track battery l is interrupted by flasher relay contact 29. lVhen the section ahead of point A. is supplied with pulsating track circuit current of normal polarity, track relay R alternately closes contacts 7l5 and 7-l6 to hold the contacts of relay L closed; contact 17 of relay K closed and 4l-12 open, hence signal S indicates proceed. Relay L holds its front contact 31 closed, and since track circuit current of normal polarity, is being supplied to relay R polar contact 27 is closed to complete the primary circuit of transformer T This circuit is from secondary 25 of transformer H through wire 36, front contact 31 of relay L wire 37, polar contact 27 of relay R wire 38, primary 24 of track transformer T and back to secondary 25. lVith this circuit closed alternating train control current is continuously supplied to the track section through wires 34 and 35.

Polar contact 28 of relay R being closed simultaneously with polar contact 27, flasher relay F will be operated by current supplied from battery G through wire 12, front contact 10 10 of relay L, polar contact 28, wire 32, contact 30 of relay F rela'y F and wire 9. Operation of relay F A will alternately open and close contact 29 so that surges of direct current from battery 4 are superimposed upon the train control current supplied to the track section through Wires 34 and 35.

Although I have shown and described only two forms of railway trailic 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. In combination, a plurality of successive sections of railway track, a polarized track relay connected across each section, a plurality of slow release relays associated with each section and controlled by the track relay of the corresponding section, a coding device controlled jointly by one slow release relay and a polar contact of the track relay at each section, and means controlled jointly by said slow release and coding devices and a polar contact of a track relay for supplying train controlling current to the track sections.

2. In combination, a plurality of sections of railway track, a track relay connected with each section and having neutral and polar contacts, and two slow-acting relays and a coding device associated with each track section, the slow-acting relays being controlled by the neutral contacts of the track relay and the coding device being controlled through a polar contact of said track relay.

3. In combination, a forward, a middle, and a rear section of railway track, a track relay connected across each section, a source of track circuit current for each section, a plurality of slow-acting relays and a coding device controlled by each track relay, and means controlled by the slow-acting relays and coding devices for supplying train controlling current to said rear section of track only when said forward and middle sections are unoccupied.

4. In combination, a plurality of successive sections of railway track, a source of track circuit current for supplying current of normal or reverse polarity depending upon traffic conditions in advance, a polarized track relay for each section, a coding device for each section and means controlled by the associated track relay for operating said coding device, a source of train control current, and means controlled by the coding device for supplying intermittent train control current to one track section when one of the two sections next in advance is supplied with track circuit current of normal polarity and the other section is supplied with track circuit current of reverse polarity.

5. In combination, a plurality of successive sections of railway track, a source of track circuit current for supplying current of normal or reverse polarity depending upon traffic conditions in advance, a polarized track relay for each section, a coding device for each section and means controlled by the associated track relay for operating said coding device, a source of train control current, and means controlled by said coding devices for simultaneously supplying intermittent'train control current and pulsating track circuit current to one track section when one of two sections next in advance is supplied with track circuit current of normal polarity and the other section is supplied with track circuit current of reverse polarity.

6. In combination, a plurality of successive sections of railway track, a track relay for each section. a plurality of slow release relays controlled by each track relay, a coding device for each section jointly controlled by the track relay and a slow release relay of each section, a source of track circuit current, a source of train control current; and v rality of slow release relays for each section and controlled by the neutral contacts of the associated track relay, a. coding device for each section controlled jointly by one of said 5 slow release relays and a polar contact of the track relay of the corresponding section, and means controlled by a coding device for simultaneously supplying intermittent train control current and pulsating track circuit current to each section when the next two sections in advance are unoccupied.

8. In an automatic train control system, a plurality of successive sections of railway track, a track relay connected to each section,

a plurality of slow release relays for each section controlled by the track relay of the corresponding section, a coding device for each section controlled by a slow release relay of the corresponding section, a source of track circuit current and a source of train control current for each section, and means controlled by the coding device of one section for normally and simultaneously supplying the preceding section with train control current and track circuit current.

9. In combination, a railway track divided into sections, a source of track circuit current for each section, a track relay for each section responsive to reversals of the polarity of the track circuit current supplied to the section, two slow acting relays for each section one controlled by a front contact of the associated track relay and the other controlled by a back contact of the associated 5 track relay, a signal for each section controlled by the slow acting relays for the section and arranged to indicate caution or alert when the first relay is energized and proceed when both said relays are energized, a pole- 40 changer associated with each signal for causing the track circuit current for the section in the rear to be of normal polarity when the signal indicates proceed, caution or alert and of reverse polarity when the signal indicates stop, and means operating when and only when the track relay for a given section is energized in normal direction to periodically interrupt the supply of track circuit current to the section next in the rear.

10. In combination, a railway track divided into sections, a source of track circuit'current for each section, a polarized track relay for each section, two slow-acting relays for each section, one controlled by a front contact of 5 the associated track relay, and the other by a back contact of the associated track relay, a signal for each section controlled by the slow-acting relays for the section and arranged to indicate caution or alert when the a first relay is energized and proceed when both of said relays are energized, a polechanger associated with each signal for causing the track circuit current for the section in the rear to be of normal polarity when 5 the signal indicates proceed, caution or alert,

and of reverse polarity when the signal indicates stop, a track transformer for each section for supplying train controlling current to the sections, the primary of each transformer being controlled by a polar contact of the track relay of the section next in advance, and a coding device operating when and only when the track relay for a given section is energized in normal direction to periodically interrupt the supply of track circuit and train controlling current to the section next in the rear.

11. In combination, a railway track divided into sections, a source of track circuit current for each section, a polarized track relay for each section, two slow-acting relays for each section one controlled by a front contact of the associated track relay and the other controlled by a back contact of the as sociated track relay, a signal for each section controlled by the slow-acting relays for the section and arranged to indicate caution or alert when the first relay is energized and proceed when both of said relays are energized, a pole-changer associated with each signal for causing the track circuit current for the section in the rear to be of normal polarity when the signal indicates proceed, caution or alert, and of reverse polarity when the signal indicates stop, a coding relay having a winding and a back contact in series, said coding relay being controlled by a polar contact of the track relay of a given section, the polar contact being closed only when the section is supplied with track circuit current of normal polarity, and a second back contact on said coding relay for controlling the supply of track circuit current to the track section in the rear of said section.

In testimony whereof I aflix my signature.

HOWARD A. THOMPSON.

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