US1704110A - Railway-traffic-controlling apparatus - Google Patents

Description

March 5, 1929. c. s. SNAVELY RAILWAY TRAFFIC CONTROLLING APPARATUS Filed May 29. 1926 Patented Mar. 5, 1929.

UNITED STATES CLARENCE S. SNAVELY, OF PITTSBURGH,

SWITCH & SIGNAL COMPANY, OF SWI OF II?ENN'SYLVANIA. V

PENNSYLVANIA, ASSIGNOR TO THE UNION SSVALE, PENNSYLVANIA, A CORPORATION RAILWAY-TR.AFFIC-CONTROLLING APPARATUS. 7

Application filed May 29, 1926. Serial- No. 112,491.

My invention relates to railway traffic controlling apparatus, and particularly to apparatus of the type comprising train carried governing means controlled by energy received from the trackway.

One object of my present invention is the provision, in apparatus of the type described, of means for supplying the trackway with alternating currents periodically interrupted at different frequencies, and governing means on the train selectively responsive to the frequency of interruption of such currents. 1 v

I will describe one form of railway traflic controlling apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a'diagrammatic view showing one form of railway traffic controlling apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate the track rails of a stretch of railway track over which traffic normally moves in the direction indicated by the arrow. These track rails are divided, by means of insulated joints 2, into a plurality of successivetrack sectionsA.B,-BC,et c. Each track section is provided with a track transformer designated by the reference character T with an exponent corresponding to the location and having a secondary constantly connected with the rails adjacent the exit end of the section through the usual impedance 6. Each track section is further provided with a polarized track relay designated by the reference character R with a suitable distinguishing v exponent and comprising two windings 8 and 9. One winding 8 of each track relay is constantly connected across the rails adjacent the entrance end of the associated section. The remaining winding 9 of each track relay is constantly supplied with alternating current from secondary 10 of an adjacent line transformer designated by the reference character J with an appropriate exponent and having its primary 11 constantly supplied with alternating current from a suitable source such as an alternator N over line wires 3 and 3. The track relays B may be used to control. governing 'means, not shown 1n the drawmg,

in any suitable manner.

' Associated with each track relay is a repeater relay designated bythe reference character P with an exponent corresponding to the location and arranged 'to be energized only when the associated track relay is encrgized in'one direction or the other. Referring particularly to relay P, the circuit for this relay may be traced from secondary 10 of transformer J through wires 19, and 21, contact 22 of relay B in the normal or reverse positions, wire 23, winding of relay P and wires 24, 25, 26, 27 and 28 back to secondary 10 of transformer J r 1 Each track section is also provided with a coding relay designated by the reference character S with an appropriate exponent. Each coding relay S comprises two windings X and Y, each made up oftwo coils 14 and 15, and a pivoted armature controlled by the yvindings. The armature 16' controls two contacts 17 and 18, which. are arranged to occupy one extreme position or the other according as armature 16 is attracted by Winding X or winding Y. Associated with each relay S is a rectifier designated by the reference character Q, with a suitable exponent. Referring particularly to relay S when relay P is energized a circuit is closed from secondary 10 .of transformer J through wires 19, 29 and 29 rectifier (2?, wires 30 and'30, front contact 31 of relay P wire 32, coil 14 of winding Y and coil 14 of winding X, wire 33, frontcontact 34 of relay P wires 35 and 36, rectifier Q and Wires 71, 27 and 28, back to secondary 10 of transformer J It will be seen thatby Virtue of this circuit, the coils 14 of windings X and Y are supplied from transformer J B with direct current which flows through the coils in series. Coil 14 of winding X is provided with a shunting circuit which may be traced from the lower terminal of this coil, through wire33, front contact 34 of relay P wires 35 and 38, back contact 39 of rela R wire 40, and contact 17-1'7 of relay B to the upper terminal of coil 14 of winding X. When contact 1717" is closed coil 14 of winding Y is shunted through a circuit which may be traced from the lower terminal of coil 14 of winding Y, through wire 32,. front contact 31 of relay P wires 30 and 41, and contact 17-1'1" of relay S back to the upper terminal of coil 14 of winding Y. As 'shownin, the drawing armature 16 is swung toward winding X but relay R is energized, so that the shunting circuit for coil 14 of winding X is open. The

shunting circuit for coil 14 of winding Y is also open at contact 17-17, but armature 16 is held by winding X in such position that contact 1717 is closed because of the re duced air gap between armature 16 and winding X, though current is supplied to coils- 14 of windings X and Y in series. Should relay R become deenergized, the shunting circuit for coil 14 of winding X would he closed. The magnetic field due to this coil would then gradually decay until the comparatively large attraction of coil 14 of winding Y would swing armature 16 toward winding Y. This reversal of the armature would open the shunt for coil 14 of winding X and would close the shunt around coil 14 of winding Y. After a time interval the increasing field of coil 14 of winding X would predominate over the decreasing field of coil 14 of winding Y and armature 16 would be swung back into the position in which it is illustrated in the drawing. It follows that when relay R is deenergized, relay S operates to close contact 18,1S and contact l818" intermittently.-

' WVhen relay P is de-energized the oper ating circuit for relay S may be traced from secondary 10 of transformer J, through wires 19, 29, and 29, rectifier Q), wires 30 and 30, back contact 31 of relay 1 wire 37, coils l5 and 14 of winding Y, coils l4 and 15 of winding X in series, wire 70, back contact 34 of relay P, wires 35 and 36, rectifier Q, and wires 71, 27 and 28 back to secondary 10 of transformer J If relay R is de-energized when relay P is de-energized, a shunting circuit for winding X is closed each time contact 1'717 of relay S closes. This shunting circuit passes from the lower terminal of this winding through wire 70, back contact 34 of relay P wires 35 and 38, back contact 39 of relay R wire 40, contact l717""of relay S and back to the upper terminal of winding X. Similarly a shunting path of low resistance is closed around winding Y when contact 1717 of relay S is closed from the lower terminal of winding Y, through wire 37, back contact 31 of relay P wires 30 and 41, contact 1717"-of relay S and back to the upper terminal of' winding Y. It follows therefore that when relay P is de-energized and relay R is also tie-energized the operation of relay S alternately closes contact 1818 and contact 1818 It should he pointed out that when relay P is energized only coils 14 of windings X and Y are included in the operating circuit for relay S, but that when relay if is de-energized, both coils of windings X and Y are included in the operating circuit. Due

to the increased reactance ofthe windings 'X and Y when both coils are included in the circuit, the operation of the relay is more rapid when only one 0011 of the winding is included in the operating circuit than when both coils are included in the circuit. The relays S may be arranged to operate at any reasonable speeds but for purposes of illustration I will assume that when relay P is energized relay S operates at 100 cycles per minute and that when relay P is de-energized, relay 8 operates at 30 cycles per min ute. It 'will he noted that when relay S is operated at either speed, if back contact 39 of relay R becomes open the shunt around that portion of winding X which is then included in the operating circuit is opened and when the armature 16 next swings toward winding X, the operation of the relay ceases and the armature remains in that position until back contact 39 of relay R is again closed.

\Vhen relay R is energized in one direction or the other, so that relay S is at rest, contact 18l8" of relay S is closed and current-is supplied without interruption to the primary 7 of transformer T from secondary 10 of transformer J B in the manner I will now describe. If relay P is energized, current is supplied from secondary 10 of transformer J, through wires 19 and 29, contact 18-18 of relay S wires 56'and 57, contact 58 of relay R wire 59, front contact 60 of relay 1 wire 61, primary 7 of transformer T", wire 62, front contact 63 of relay P, and wires 64, 26, 27 and 28, back to secondary '10 of transformer J. This circuit is closed only when relays P and B" are energized and when contact 1818 of relay SP is closed, under which condition current ofnormal rela tive polarity is supplied to the rails of SLL tion AB, thereby swinging contacts 22, 5b and 39 of relay R to the right. When relay P is dc-energized, however, current from sec ondary 10 of transformer J flows through wires 19 and 29, contact 1818 of relay s", wires 56 and 65, back contact 63 of relay P wire 62, primary 7 of transformer T, wire 61, back contact 60 of relay P and wires 64, 26, 27 and 28 back to secondary 10 of trans former J. When this circuit is closed current of reverse relative polarity is supplied to the rails of section AB and relay R is energized in the reverse direction so that the contacts of this relay are swung to the left.

Means are also provided for at times supplying each track section with interrupted alternating train controlling current. The immediate source of this train controlling current for each track section is a transformer designated by the reference character K with an exponent corresponding to thelocation and having a primary 13 constantly supplied with alternating current from a suitable source such as an alternator M over line wires and 4. The frequency of the current supplied by alternator N is different from that. supplied by alternator and since current fromaltcrnat-or N is supplied to the trackway for energizing the track relays these relays are constructed to respond only to cur-- K by alternator M is of 100 cycles per second butthese particular frequencies are not essential and have been mentioned simply-for purposes of illustration.

Train controlling current is supplied to the rails of a section only when the coding relay S for that section is operating. Forlay S is at rest and the track circuit current example, when relay 1? is energized and when relay R is de-energized to operate relay S at 100 cycles per minute, an impulse of train controlling current is supplied to primary 7 of transformer T for each cycle of operation of relay S the circuit being traced from secondary 12 of transformer K through wire 42, contact 18-18" of relay S wires 56 and 57, contact 58 of relay R wire 59, front contact 60 of relay P Wire 61, primary 7 of transformer T wire 62, front contact 63 of relay P and wires 64, 26,27 and 43, back to secondary 12 of transformer K When relays R and P are energized, then, and when relay S is operating, the rails of the section AB are'supplied with an impulse of train controlling current each time contact 1818 of relay S is closed, and with an impulse of track circuit current each time contact 18-18'- is closed. lit follows that the rails of the section are then supplied with, alternate impulses of train controlling current and track circuit current, the frequency of the-impulses of each current being 100 cycles per minute. Train controlling current supplied to the rails at this frequency of interruption I shall term the proceed code. When relay P is-deenergized and when relay S is operating, an impulse of train controlling current is supplied as before to the trackway each time con tact 1818 is closed, the circuit for transformer T then passing from secondary 12 of transformer K through wire 42, contact 18--18 of relay S wires 56. and 65, back contact 63 of relay P wire 62, primary 7 of transformer T wire 61, back contact 60 of p relay P 'and wires 64, 26, 27 and 43 back to the section in the form of impulses having a secondary 12 of transformer K When this circuit is closed and when relay R is deenergized relay S operates at 30 cycles per minute,.and the rails of section A'B are supplied with alternate impulses of train controlling current .and of track circuit current, the'frequency of interruption of each current being 30 cycles per-minute. Train controlling current supplied to the rails of frequency of 30 cycles per minute, I shall term the caution code.

As shown in the drawingthe section to the right of point C is occupied by a train-indicated diagrammatically at V. Relay R is therefore de-energized and relay P is also deenergized. Trackcircuit current of reverse relative polarity is therefore supplied to the rails of section B-G. Relay B is therefore energized in the reverse directionvso that relay S is at rest arid the track' circuit current supplied to section BC is uninterrupted.

No train controlling current is supplied to the rails of section BG. Relay P is energized and track circuit current of normal relative polarity is therefore supplied to the rails of section AB. Relay Rtis therefore energized .in the normal direction so that resuppliedfto section 'A- B is uninterrupted. In similar manner relayP is energized, but the section to the left of point A is occupied by a second train V, so that the track relay for this section is de-energized and relay S is operating at 100 cycles per minute. The

rails of the section to the left of point A are therefore supplied with train controlling current in the form of a proceed code, and during the interval between successive impulses of such train controlling current,

track circuit current of normal relative polarityis supplied to the rails of the section.

Carried upon the train V in advance'of the forward axleis a receiver W comprising two magnetizable cores 66 and 66" located in inductive relation with the track rails 1 and 1 respectively. Core 66 is provided with a winding 67, and core 66*- is provided with a similar winding 67 the two windings 67 and 67 being connected in series in such manner that the voltages induced therein by train" controlling currents flowing in opposite directions in the two track rails at an instant are additive. The windings 67 and 67 of the receiver W are connected, through an amplifier 68 and a rectifier 69 with a relay D. By

means of a condenser 80, the windings 67 and 67 arev tuned to resonance at the frequency of the train controlling current so that the relay D is energized by train controlling current but not by 60 cycle track circuit current in the track rails. It follows that relay D is intermittently energized when the rails 0ccupied by the train V are supplied with train controlling current, the frequency of energization of relay 1) corresponding to the frequency of interruption of such train controlling current.

' The reference characters G and Gr designate two" transformers each comprising a magnetizable core 44 and a secondary 47. When relay Dis intermittently energized, periodically varying fluxes of a frequency corresponding to the frequency of energization of relay D are created inthe cores of transformers G and G As here shown this is D is energized, :direct current is supplied from a suitable source such as a battery F, to primaries 45 of transformers G and Gr in parallel. When relay D is de-energized, however, direct current flows through primaries 46 of these transformers in parallel from battery F. It will be noted that current flows in opposite directions through the two primaries of each transformer and it follows that when relay D is being energized intermittently by the interrupted train controlling current, the magnetic fluxes in transformers G and G are periodically reversed at a frequency corresponding to the frequency of interruption of the train controlling current received by relay D. Secondary 47 of transformer G is connected, through a rectifier L with a direct current relay E .The rectifier L may be of any suitable type and as here shown comprises fourasymmetrical units 48 so arranged that current in relay E always flows in a direction from the righthand terminal to the left-hand terminal of the relay. The variations in the flux in the core of transformer G create surges of current in relay E and to assist the relay in holding closed its front contact during successive surges I connect an asymmetrical unit 49 in parallel with the relay E. This unit 49 is arranged to offer a high resistance to current supplied from rectifier L but to offer a low resistance to current resulting from the decaying field of the relay winding during the interval of time between successive impulses supplied to the relay. The snubbing effect of the unit 49 therefore renders relay E slow releasing but does not interfere with the quick pick-up of the relay. It should also be pointed out that the asymmetrical units of rectifier L assist in this snubbing effect, the units 48 comprising two parallel paths each containing two of the units'in series and conducting current in the same direction as unit 49 during the decay of the field of relay El.

In similar manner a second relay E is connected with secondary 47 of transformer G through a rectifier L and is provided with an asymmetrical unit 49 connected in parallel therewith.

It is well known that if a transformer is designed so that for an input electromotive force of one amplitude and frequency the core is substantially saturated, a certain amount of energy will be delivered at that frequency and atleast as much energy will be delivered at higher frequencies, but that at lower frequencies with the same amplitude of electromotive force a smaller amount of energy is delivered by the transformer. I take advantage of this principle to select between the caution and proceed codes on board the train.

This is accomplished by so proportioning the parts that when the flux in transformer G is being reversed 30 times per minute, as

when relay D is receiving the caution code, the

core of the transformer-is substantially saturated and relay E is supplied with suflicient energy to pick up the relay. It follows that relay E will also be energized when the flux is being reversed 100 times per minute, as when relay D is receiving the proceed code. Transformer G is so proportioned that when the flux is being reversed 100 times per minute, its core is substantially saturated and sufficient energy is supplied to relay E to pick up the relay.- When the caution code is being received, however, relay E is de-energized, because the reversals of flux are of the same amplitude .as for the proceed code, due to the saturation of the core, and since theyare less rapid the energy supplied to the relay E is not sufficient to energize the relay.

I will now assume that the train V proceeds through the stretch of track shown in the drawing. While the train is in the section to the left of point A, the proceed code supplied to the rails of this section energizes relay D intermittently at the rate of 100 cycles, per minute. Relays E and L are therefore both energized so that current flows from battery F, through front contact 5151" of relay E to lamp 53, lighting this lamp to indicate proceed. As the train enters sec-Zion. AB, the de-energization of relay R sets relay S into operation. Relay P is energizedand relay S therefore operates at 100 cycles per minute. The rails are therefore supplied with train controlling current in accordance with the proceed code so that as the train proceeds through section A-B .relays E and E .remain in their energized conditions and lamp 53 remains lighted to indicate proceed. As the train enters section BC, relay R becomes de-energized and sets relay S into operation. Relay P is de-energized, however, so that relay S operates at 30 cycles per minute. Train controlling current is there fore supplied to the rails of section BC in accordance with the caution code. Relay D is therefore energized intermittently 30 times each minute.v Asa result the fluxes in transformers G and G are reversed 30 times each minute. The energy thus supplied to relay E is not sufiicient to hold this relay inv its energized condition so that this relay opens but relay E is held in its energized condition. Current then flows from battery F, over back contact 5151 of relay E and front contact 52-52 of relay E to lamp 54, energizing this lamp to indicate caution. Should the train enter the section to the right of point C, relay D would be deprived of train controlling cur.- rent and would be continuously de-energized so that relays E and E would both be deenergized and current from battery F would flow to lamp 55 over back contact 51-51 of relay E? and back contact 52.52 of relay E Lamp 55 would then be lighted to indicate stop. a

When the train passes out of section AB, the next impulse of track circuit current enerquency,

gizes relay R and opens the shunt around the portion of winding X then included in the operating circuit for relay 8, thereby causing the operation of this relay to cease, and discontinuing the interruption in the track circuit current supplied to the section. At the same time the stopping of relay S completely interrupts the supply of train controlling current to the rails of the section. In similar manner when a train leaves any of the remaining sections the operation of the coding relay for that section immediately ceases and uninterrupted track circuit current is thereafter supplied to the rails of the section as long as the section is unoccupied.

In this application I have shown the coding relays S provided with only two coils in each winding to give two speeds for the relay, and the train carriedapparatus is arranged to select between only two frequencies of the interruptions of the train controlling current, but it should'be clearly understood that this limitation is not necessary and that any reasonable number of codes of different frequencies could be'used. i Although I have herein shown and described only one form of railway trafiic 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 departin from the spirit and scope of my invention.

.IIaving thus described my invention what I claim is:

1. In combination, a source of periodically varying electromotive forces of constant amplitude but different frequencies, a transformer having a primary receiving energy from said source and a core substantially saturated when the primary is supplied with an electromotive force of one freand a current consuming device connected with er and requiring for its operation the amount of power supplied thereto when the primary of the transformer is receiving an electromotive force of such one frequency.

2. In combination a transformer, means for supplying the primary of said transformer with periodically varying electromotive forces of difierent frequencies but constant amplitude, and a current consuming device connected with the secondary of said transformer and arranged to be operated only if the primary of the transformer is supplied with an electromotive force at a frequency at least as great as that required to substantially saturate the transformer core.

3. In combination, a source of direct current, a contact operating at times at different frequencies, a transformer having a primury connected with said source through said contact, the core of said transformer being substantially saturatedwhen said contact is operating at one frequency, and a'eurthe secondary of saidtransform rent consuming device connected with the I secondary of said transformer and arranged to be operated only when said contact is operating at said one frequency or at a higher frequency.

4. In combination, a source of periodically varying electromotive forces of constant amplitude but different frequencies, two transformers each having a primary reoeivingencrgy from said source and the cores of said transformers being substantially saturated at different frequencies of the electromotive forces, and two current consuming devices one connected with the secondary of each transformer and each arranged to be energized only when the frequency of the electromotive force applied to the associated primary is equal to or above the frequency required to saturate its core.

5. Railway traflic controlling apparatus comprising a train carried relay at times energized intermittently at difierentfrequencies, two transformers each having a primary supplied with periodically varying current the frequency of which depends upon the he quency of energization of said relay, the cores of said transformers being substantially saturated at difierent frequencies of the current supplied to the associated primaries, and governing means selectively controlled by said transformers in accordance with the frequency of energization of said relay.

6. Railway trafiic controlling apparatus comprising a train carried relay at times onergized intermittently at different frequencies, two transformers each having a primary supplied with periodically varying current the frequency of which depends upon the frequency of energization of said relay, two other relays one connected with the second ary of each said transformer, a rectifier interposed between each such relay and the associated transformer secondary, and governing means selectively controlled by said other relays in accordance with the frequency of energization of said train carried relay.

7. In combination, two transformers, means for supplying the primaries of both said transformers with periodically varying electromotive forces of different frequencies, and two current consuming devices one connected with the secondary of each transformer, the transformer cores being substantially saturated at different frequencies of the electromotive forces supplied to the primaries thereof so that the devices are energized only when the frequencies of saidelectromotive forces are above different values.

8. Railway traffic controlling apparatus comprising a train carried relay at times energized intermittently at different frequencies, two transformers having different saturation characteristics, means controlled by said relay for creating in said t1 ansformers periodically varying fluxes the frequencies of which vary in accordance with the frequency of cnergization of said relay, two selector relays one connected with the secondary of each transformer, a rectifier interposed beiween each such selector relay and the associated transformer secondary, and governing means selectively controlled by said selector relays in accordance with the frequency of energization of said train carried relay.

9. In combination, two transformers, means for at times creating in the cores of said transformers periodically varying fluxes of one frequency and for at other times creating in such cores periodically varying fluxes of a different frequency, one core being saturated by flux of the first frequency and the other core being saturated by flux of the other frequency, two current consuming devices one connected with the secondary of each transformer and each arranged to be energized only when the associated transformer is being supplied with flux at a frequency at least as high as the frequency at which the core of such transformer becomes saturated.

10. In combination a first relay at times intermittently energized at different frequencies, two transformers, means controlled by said first relay for supplying current to the primaries of said transformers, two relays one connected with the secondary of each transformer and so arranged that one relay is energized when the frequency of energization of said first relay is above a predetermined low value and below a predetermined higher value but that both said relays are encrgized when the frequency of energization of said first relay is above said higher value.

1.1. In combination, a stretch of railway track, a contact, means for operating said contact intermittently at different speeds, and means including said contact for supplying current to the stretch.

12. In combination, a stretch of railway track, a coding relay comprising a contact arranged to be periodically closed at different frequencies, and means controlled by said contact for supplying alternating current to the rails of said stretch. 13. In combination, a stretch of railway track, a contact, a source of alternating current, means including said contact for con necting said source with the rails of the stretch, and means for at times repeatedly opening and closing said contact at different speeds.

14- In combination, a stretch of railway track, a coding relay comprising a contact at times operated intermittently, means for varying the speed of operation of said contact, a first source of alternating current, means including said contact for at times connecting said first source with the rails of the stretch, a second source of alternating current, and means effective only when said first source is disconnected from the rails for connecting said second source with the rails of the stretch.

15. In combination, a stretch of railway track, means including a coding relay for supplying the rails of the stretch with alternate impulses of alternating currents of different frequencies, and means for at times varying the speed of operation of said coding relay to vary the frequency of the impulses supplied to the trackway.

16. In combination, a stretch of railway track, a multiple speed coding relay comprising a movable armature, two windings for moving the armature in opposite directions, means for supplying current to a selected portion of each winding, .Ineans controlled by said armature for alternately shunting such selected portion of said windings, a contact controlled by said armature, and means including said contact for at times supplying interrupted alternating current to the rails of the stretch.

17. Railway traffic controlling apparatus comprising a stretch ofrailwaytrack,amultiple speed coding relay comprising a movable armature, two windings for moving the armature in opposite directions, means for supplying current to a selected portion of each winding, means controlled by said armature for alternately shunting such selected portion of said windings, a source of alternating eurrcnt, a contact controlled by said armature, means including said contact for at times supplying the rails with alternating current interrupted at different frequencies depending upon the operating speed of the relay, and governing means on a train selectively responsive to such interruptions.

18. In combination, a stretch of railway track, a relay comprising a movable armature, two windings arranged when energized to move the armature in opposite directions, means for supplying current to said windings, means controlled by the armature for alternately shunting said windings, means controlled by said armature for supplying interrupted current to thestretch, and means effective when said stretch is unoccupied to prevent the shunting of one said winding to stop the relay.

19. In combination, a stretch of railway track, a relay comprising a movable armature, two windings arranged when energized to move the armature in opposite directions, means for supplying current to said windings, means controlled by the armature for alternately shunting said windings, means controlled by said armature and effective when the relay is operating to supply said stretch with alternate impulses of track circuit current and train controlling current, and means effective when the stretch is unoccupied to prevent the shunting of one of said winding to stop the relay in such positionthat the quencies, means for translating said ,variastretch is supplied continuously with track tions into alternating currents of the same circuit current. frequencies as the variations, and governing 1o 20. Railway traific controlling apparatus means selectively controlled by said last 5 comprising means for supplying the tracknamed current.

Way with alternating current having its In testimony whereof I aflix my signature. amplitude periodically varied atdifi'erent fre- CLARENCE S. SNAVELY.

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