US2182163A - Railway signaling apparatus - Google Patents

Description

Dec. 5, 1939. w. P. PLACE RAILWAY SIGNALING APPARATUS Filed April 6, 1939 W 1g X I [b 14 i;

W' ml Com al Circuit.

INVENTOR we! 121 66209.

HIS ATTOR N EY Patented Dec. 5, 1939 v UNITED STATES PATENT OFFICE RAILWAY SIGNALING APPARATUS Willard P. Place, Wilkinsburg, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application April 6, 1939, Serial No. 266,368

11 Claims. (Cl. 2l634) My invention relates to railway signaling appreferably consists of several cells connected in paratus, and more particularly to apparatus for series to produce a relatively high voltage, such railway track circuits. as, for example, a ten volt storage battery.

A feature of my invention is the provision of The transmitting relay or coder CT :is prefer- 5; novelv and improved apparatus for supplying a ably of the neutral relay type having slow pick- 5".

track circuit with periodically interrupted or time up characteristics. In the form here shown the spaced current impulses of relatively high volttransmitting relay CT is provided with a top or age and short duration, and the duration of which operating winding i and a lower or retarding is varied according to dry and wet ballast condi- Winding 5, the winding 5 being short circuited tions so that a substantially uniform energizaover a back contact 6 of the relay so that the relay 10 tion of the track relay is efiected over a relatively is slow to pick up when the operating winding 4 is wide range of ballast resistance. The high voltenergized. The auxiliary relay AR is preferably age of the current impulses is of aid to the shunta quick acting neutral relay.

ing sensitivity of the track circuit because such The track battery 3 is connected across the Ill, voltage breaks down the rail film resistance. rails la and lb over the two conductors 6 and 1 V The short duration of such current impulses reand preferably in a manner so as to supply the quires only a low energy output of the track track circuit with current of a predetermined battery or other current source. Another feature polarity. To be explicit, the negative terminal of my invention is the provision of novel and imof battery 3 is connected with conductor l over proved track relay means for a track circuit which a protective device or fuse 8 and a front contact 20 is responsive to time spaced current impulses 9 of the transmitting relay CT, and the positive notwithstanding such impulses are badly disterminal of battery 3 s c ed W t c ufitorted in wave form and which means also makes tor 6 over a current limiting resistor It. The it possible to maintain a signal control relay eneroperating winding 4 of relay CT is connected 5 gized from a low voltage source of control curacross battery 3 over the back contact ll of the 5 rent. Other features and advantages of my inauxiliary relay AR as will be readily understood vention will appear as the specification progresses. by an inspection of Fig. l. The winding ii of I shall describe two forms of apparatus embodythe auxiliary relay AR is connected across the ing my invention, and shall then point out the track rails by being connected directly with the novel features thereof in claims. conductors 6 and l which conductors possess an 30 In the accompanying drawings, Figs. 1 and 2 appreciable amount of ohmic resistance. It folare diagrammatic views of two different forms of lows that when the front contact 9 of relay CT apparatus each of which embodies my invention. is closed and current is supplied from track bat-' In each of the two views like reference charactery 3 to the track circuit over conductors 6 and ters designate similar parts. l the winding ll of relay AR receives current in 35.

Referring to Fig. 1, the reference characters la shunt with the track circuit. With relay AR and lb designate the track rails of a stretch of energized and picked up opening back contact ll railway over which trafiic normally moves in the the current to the operating winding 4 of relay direction indicated by an arrow and which'rails CT is interrupted and relay CT is deenergized 40 are formed by the usual insulated rail joints with and immediately releases opening front contact 40 a track section WX. The track section W--X 9 and removing current from the track circuit is provided with a track circuit for signaling. and also from the winding I? of relay AR. Relay This track circuit for section W-X comprises AR is now deenergized and releases closing back transmitting or coding means for supplying across contact H to reenergize the operating winding 4 the rails la and lb at the exit end of the section of the transmitting relay CT. It is apparent that 45 periodically interrupted or time spaced current relays CT and AR will have a cyclic operation, impulses, and a track relay connected across the the cycle interval being determined largely by rails at the entrance end of the section. The the slow pick-up period provided for the relay means for supplying time spaced current impulses CT and relay CT being retained picked up a relamay take different forms and as here shown it tively short period of each cycle interval because 50 includes a track battery 3, a transmitting relay of the relatively quick pick-up period of relay AR. or coder CT, an auxiliary relay AR, a ,current It is to be noted that the ballast resistance limiting resistor ill, a protective device 8 and two path between the track rails la and lb forms a track conductors 6 and 1 connected to the rails shunt path to the winding l2 of relay AR. Hence la and lb, respectively. The track battery 3 under dry ballast conditions and the rail to. rail 55 ballast path of relatively high resistance so that the leakage current is low, the voltage drop at resistor H3 is low and substantially the full voltage of battery 3 is applied to winding I2 of relay AR and relay AR picks up correspondingly quick. Under wet ballast conditions and the rail to rail resistance path of relatively low resistance the increased flow of leakage current causes a relatively large voltage drop at resistor Hi and the voltage applied to the operating winding l2 of relay AR is correspondingly low, causing that relay to pick up correspondingly slow. Consequently, under dry ballast conditions the period the transmitting relay CT remains picked up is correspondingly short due to relay AR picking up quickly sothat the duration of the current im.-, pulse supplied to the track circuit over front contact 9 of transmitting relay CT is correspondingly short. Under wet ballast conditions the period the transmitting relay CT remains picked up is correspondingly long due to relay AR picking up slowly so that the duration of the current impulse supplied to the track circuits is c0rresnondingly long.

It is to be seen, therefore, that time spaced impulses of direct current of a predetermined polarity are supplied to the track circuit of section WX, the impulses being of relatively high voltage and of short duration, the duration of the impulses being short compared with the interval between successive impulses and the duration of the impulses being automatically varied according to the ballast conditions.

It should be observed that Contact a of the transmitting relay CT is preferably of the socalled safety type, that is, a contact adaptable of breaking a high voltage. It should also be observed that in the event of a circuit cross or ground and the transmitting relay CT fails in its operation with front contact 9 closed so that the magnitude of the current supplied from battery 3 is large, the fuse 3 would shortly melt and open this circuit removing all current from the track rails.

The track relay for the track circuit of section WX is a direct current relay TRI, the operating winding ll of which is connected across the rails la and lb over conductors 13 and [4, respectively. A resistor l and a rectifier iii are connected in multiple across the operating winding 4i of relay TRI to give the relay quick pickup and slow release characteristics.

.When the section WX is unoccupied, the short high Voltage current impulses applied across the railseffectively energize and pick upthe track relay TRl, the relay TR! remaining picked up from one impulse to the next due to its slow release characteristic. The total energy available for energizing the relay TRI is substantially uniform under both dry and wet ballast conditions since under dry ballast conditions the voltage of the impulses will be correspondingly high and the duration of each impulse will be correspondingly short, and under Wet ballast conditions the voltage of the impulses will be correspondingly low and the duration of the impulses will be correspondingly long because of the action of the auxiliary relay AR as explained hereinbefore. I

It is to be noted that since the track relay TRl is slow releasing in character and is energized and retained picked up from one current impulse to the next the wave form of the individual impulses may be badly distorted because of track circuit conditions without causing an unfavorable operation of relay TRI.

When the track section WX is occupied relaysAR and CT are periodically operated, such operation being aided by the resistance possessed by conductors l3 and l, and the relatively high voltage of the current impulses breaks down the rail film resistance and track relay TR! is shunted, the track circuit for section WX having a relatively high shunting sensitivity.

The track relay TB! is used to control any desired signal control circuit of the usual form and as here shown the signal control circuit includes front contact ll of relay 'IRl. I

In Fig. 2, the track rails la and lb of a stretch of railway are formed with a track section WX having a track circuit the same as in Fig. 1. The means for supplying time spaced current impulses of relatively high voltage and short duration to the track circuit of section WX of Fig. 2 is the same as in Fig. 1.

. In Fig. 2, the track relay means includes a code following relay TRZ connected across the rails at the entrance end of the section WX. Hence, when section WX is unoccupied the track relay TR2 is effectively energized and picked up closing front contact 22 during the on period of each current impulse supplied to the track circuit of section WX, and relay TRB is deenergized and released during the off period of each current impulse, that is, during the interval between successive impulses. Since the duration of the current impulses is short compared With the duration between successive impulses the on period of the relay TRZ is short compared with the off period of the relay. The energy available, however, for picking up the track relay TRZ in response to each current impulse is substantially uniform over a relatively wide range of ballast resistance due to the operation of the auxiliary relay AR causing the individual impulses to be correspondingly short under dry ballast conditions and correspondingly long under wet ballast conditions. Such unequal and varied on and off periods in the operation of relay TR2 isimmaterial to the operation of the apparatus governed by the relay TR? as will shortly appear. When the track section WX is occupied the track relayyTRZ is shunted and is inactive, the track circuit for section WX having a relatively high degree of shunting sensitivity due to the relatively high voltage of the current impulses.

The track relay means of Fig. 2 also includes a polar relay PR, a decoding transformer DT, a control relay CR and a low voltage control battery H3.

The polar relay PR is provided with a normal winding NW and a reverse winding RW, the arrangement being suchthat when normal winding NW is. energized over a circuit to be shortly described the polar contact members I9, 20 and 2! of relay PR are operated to the normal or left-hand position as viewed in Fig. 2. When the reverse winding RW is energized by a circuit tions, and notwithstanding the wave form of the of the relay from its last position, the polar armature moves to its other extreme position although the energizing current ceases.

A relay which may be made to operate in a manner just described is disclosed in the Letters Patent of the United States No. 1,790,671, granted February 3, 1931, to Branko Lazich for Electrical relays. In the instant application the polar relay PR is provided with two windings disposed for. reversibly energizing the relay whereas in the patent the relay is shown provided with a single winding to which current is reversibly supplied, such equivalent arrangements of the windings of a polar relay being readily understood by those skilled in the art.

When relay TRZ is picked up closing front contact 22 current flows from battery 18 over front contact 22 of relay TRTZ, reverse winding RW of relay PR, normal polar contact Iii-23 and back to battery 58, and relay PR is operated to move its contact members I9, 20 and 2| to the reverse or right-hand position. On the next current impulse of the track circuit and track relay TRZ is again picked up closing front contact 22, current flows from battery [3 over front contact 22, normal winding NW of relay PR, reverse polar contact ill-24 of relay PR and back to battery 18, and relay PR. operates its contact members i9, 29 and 2! to the normal or left-hand position. It follows that the polar relay PR is operated to its reverse position in response to each odd impulse of the track circuit current and is operated to the normal position in response to each even impulse of the track circuit current. Furthermore, because of the operating characteristics of relay PR it is clear that the relay will be operated notwithstanding the on and off periods of the operation of the code following relay 'IRZ are unequal and are varied.

With polar relay PR thus operated current from battery i8 is alternately supplied over normal polar contact 20-26 and reverse polar contact 2ll2l to the two portions of the primary winding 25 of transformer DT. Such alternate energization of the two portions of primary winding 25 induces an alternating electromotive force in the two portions of the secondary winding 28 of transformer DT and which electromotive force is rectified and applied to the winding 29 of control relay CR. over normal polar contact 2I-3ii and reverse polar contact 2|3l with the result that rectified current flows in the winding 29 always in the same direction and relay CR is effectively energized and picked up closing front contact 32 interposed in a signal control circuit. Relay CR- remains picked up closing front contact 32 as long as relay PR is operated since relayCR is provided with slow release characteristies. The ratio of the turns of the primary winding 25 to the turns of the secondary winding 23 of transformer DT is chosen so that relay CR is effectively energized from battery 18 when battery I8 is a single cell low voltage battery. The condensers 33 and 34 may be provided and connected as shown in Fig. 2 to suppress sparking at the contacts of the polar relay PR.

It is to be seen, therefore, that the signal control circuit including front contact 32 of relay CR is effectively governed from a low voltage control battery and in response to track circuit current impulses which are of relatively short duration compared with the duration between successive impulses, and which durations are varied in response to changes in ballast condicurrent impulses may be badly distorted.

It should be observed that the windings NW and RW may be connected directly with the track rails of section W--X andthe polar relay PR operated directly by the track circuit current impulses.

Although in both Figs. 1 and 2 the source of supply for the track circuit is shown as a battery 3 of the voltage of the order of 10 volts, it is to be understood that my invention is not limited to a battery of such voltage and connected with the polarity as shown in the drawing. Also an alternating current source maybe used onthe track circuit and relays CT and AR made alternating current relays of any of'the several wellknown types. Although I have herein shown and described only two forms of apparatus embodying my invention, it is understood that various changes and modifications maybe 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 track section, a source of direct current, transmitting means operative to connect said source across the rails at one end of the section for supplying to said rails time spaced impulses of current, means connected across the rails at said one end of the section variably afiected by wet and dry ballast conditions of the section to control the duration of each of said impulses of current, and a track relay connected across the rails at the other end of the section effectively energized by said impulses of current.

2. In combination, a track section, a source of direct current, transmitting means for periodically connecting said source across the rails at one end of said section to supply recurrent impulses of direct current to said rails, means connected with the rails responsive to changes in ballast conditions of said section to vary the duration of each of such current impulses to cause such impulses to be relatively short under dry ballast conditions and relatively long under wet ballast conditions, and a track relay connected across therails at the other end of said section energized by said current impulses at substantially the same energy level for both dry and Wet ballast conditions.

3. In combination, a track section, a source of direct current, a transmitting relay effective when energized to supply current from said source to the rails at one end of said section, an auxiliary relay connected across the rails at said one end of the section energized by said current supplied to the rails for picking up said auxiliary relay in an interval which is varied due to variations in the shunting action of dry and wet ballast conditions of the section, means including a back contact of said auxiliary relay to energize said transmitting relay to cause the current supplied to the rails to be relatively short current impulses under dry ballast conditions and relatively long current impulses under wet ballast conditions, and a track relay connected across the rails at the other end of said section energized by said current impulses at an energy level,

4. In combination, a track section, two conductors connected one with each rail at one end of the section; atrackbattery;aitransmitting-re lay, means includinga front contact of said transmitting relay to connect said battery with said conductors to-supply current to the rails of said section, an auxiliary relay having its winding connected with saidconductors to pick up the auxiliary relay subsequent to the closing of said front contact of the transmitting relay in a time interval varied by the variations in the shunting action caused by dry and wet ballast resistances of the section, means including a back contact of said auxiliary relayto connect 'a-winding of said transmitting relay across said battery to cause a cyclic operation of said relays with the period the transmitting relay is picked up and current supplied to the .rails correspondingly short under dry ballast resistance and correspondingly long under wet ballast resistance, and a track relay connected across the rails at the other end of the section energized by current thusintermittently supplied to the rails at an energy level substantially the same for both dry and wet ballast resistances.

5. In combination, a track section, two conductors connected one with each rail at the exit end of said section, a track battery of relatively high voltage, a slow pick-up relay, an auxiliary relay, means including a front contact of said slow pick up relay to connect said battery with said conductors to supply current to the rails of said section at a relatively high voltage, means to connect a winding of said auxiliary relay with said conductors for picking up the auxiliary relay subsequent to the closing of said front contact of the slow pick-up relay in a time interval dependent upon the shunting action of the ballast resistance of the section, means including a back contact of said auxiliary relay toconnect a winding of said slow pick-up relay, across said battery to provide a cyclic operation of said relays with the period the front contact of the slow pick-up relay is closed correspondingly short under dry ballast conditions and correspondingly long under wet ballast conditions, and a track relay ccnnected across the rails at the entrance end of the section energized by the current impulses supplied to the rails when the section is unoccupied at substantially the same energy leVeHrrespective of ballast conditions and said track relay effectively shunted when the section is occupied due to the high voltage of such current impulse breaking down the rail film resistance.

6. In combination, a track section, two con ductors connected one with each .rail at the exit end of said section, a track battery of the order 1 of ten volts, a transmitting relay, an auxiliary relay, means including a front contact of said transmitting relay to connect said battery with said conductors to supply current to the rails of said section, means to connect a winding of said auxiliary relay with said conductors to pick up the auxiliary relay when said front contact of the transmitting relay is closed in a time interval varied due to the varied shunting action of the ballast resistance of the section, means including a back contact of said auxiliary relay to connect a Winding of said transmitting relay across said battery to cause a cyclic operation of said relays with the period the transmitting relay is picked up each cycle and current supplied to the rails relatively short under dry ballast conditions and relatively long under wet ballast conditions, and

- a track relay connected across the rails at the entrance end of the section energized by said current impulses when the section is unoccupied at substantially the same energy level for both dry and wet ballast conditions and said relay shunted when the section is occupied with high sensitivity due to the ten volts of such current impulses breaking down the rail filmresistance.

'7. In combination, a track section, a track battery of theorder of ten volts, a slow pick-up relay, a quick acting auxiliary relay, means in cluding a back contact of said auxiliary relay to connect a winding of said slow pick-up relay across said battery to energize said slow pick-up relay, means including a front contact of said slow pick-up relay to connect a winding of said auxiliary relay across said battery to energize said auxiliary relay and cause a cyclic operation otsaid relays, other means including said front contact of the slow-pickeup relay to connect said battery across the rails at one end of the section to supply to the rails of said section recurrent impulses of direct current eachoi which has a peak voltage of the order of ten volts and a short duration due to the quick pick-up interval of said auxiliary relay, and a track relay connected across the rails at the other end of the section eiiectively energized by such current impulses when the section is unoccupied and efifectively shunted when the section is occupied due to said peak voltage of said impulses breaking down the rail film resistance.

8. In combination, a track section, transmitting means including a source of direct current and a vibratory contact connected across. the rails at one end of said section for supplying to the rails time spaced impulses of direct current, a polar relay having a normal and a reverse energizing windin and characterized by polar contact members which'when moved away from one extreme position move to the other extreme position although the energizing current ceases, a first circuit including the reverse winding and a normal polar contact of said polar relay made efiective to operate the polar relay in response to each odd numbered rail current impulse, a second circuit including the normal winding and a reverse polar contact of said polar relay made efiective to operate the polar relay in response to each even numbered rail current impulse, whereby said polar relay is operated in step with said time spaced current impulse supplied to the rails, and a signal control circuit controlled by, such operation of said polar relay.

9. In combination, a track section, transmitting means including a periodically operated contact and a source of direct current connected across the rails at one end of the section to supply to the rails time spaced impulses of direct current, a track relay connected across the rails at the other end of the section biased to one position and operated to a second position in response to each of said current impulses, another source of direct current, a polar relay having a normal and a-revers'e winding and characterized by polar contact members which when moved away from one extreme position move to the other extreme position although the energizing current ceases; a first circuit including said other source, asecond position contact of said track relay, said reverse winding and a normal polar contactof said polar relay; a second circuit including said other source, a second position contact of said track relay, said normal winding and a reverse polar contact of the polar relay; a transformer, a signal control relay; means including said other source and a normal and a reverse polar contact of said polar relay for alternately supplying current to two portions of the primary winding of said transformer, other means including a normal and a reverse polar contact of said polar relay to alternately connect two portions of the secondary winding of said transformer to said control relay to energize said control relay by current induced in said secondary winding, and a signal control circuit governed by said control relay.

10. In combination, a track section, transmitting means including a source of direct current and an operated contact connected across the rails at one end of said section to supply to the rails time spaced impulses of direct current, a track relay connected across the rails at the other end of said section biased to one position and operated to a second position in response to each of said current impudses, a polar relay having a normal and a reverse Winding, another source of direct current; a first circuit including said other source, a second position contact of said track relay, said reverse winding and a normal polar contact of the polar relay; 2. second circuit including said other source, a second position contact of said track relay, said normal winding of the polar relay and a reverse polar contact of the polar relay; and a signal control circuit controlled by said polar relay.

11. In combination, a track section, a track battery of the order of ten volts, a slow pick-up relay, a quick acting relay, means including a back contact of said quick acting relay to connect a winding of said slow pick-up relay across said battery, means including a front contact of said slow pick-up relay to connect a winding of said quick acting relay across said battery to cause a cyclic operation of said relays with said slow pick-up relay picked up for a relatively short period of each cycle interval, means including a front contact of said slow pick-up relay to connect said battery across the rails at one end of the section to supply to the rails time spaced impulses of direct current of relatively short duration and of a voltage of the order of ten volts, and a track relay connected across the rails at the other end of the section eiTectively energized when said section is unoccupied by said current impulses with a small expenditure of energy by said battery and said track relay highly sensitive to the train shunt when the section is occupied due to the breaking down of the rail film by said voltage of the impulses.

WILLARD P. PLACE.

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