US868231A - Signaling system for electric railways. - Google Patents

Description

PATENTED' OCT. 15, 1907.

L. H. THULLEN. SIGNALING SYSTEM FOR ELECTRIC RAILWAYS.

APPLICATION PILED APR. 30, 1907.-

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@ 01 in cows No. 868,231. IATENTED OCT. 15, 1907. L. H. THULLEN. SIGNALING SYSTEM FOR ELECTRIC RAILWAYS.

APPLICATION IILBD APR. 30, 1907.

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witnesses SIGNALING SYSTEM FOR ELECTRIC RAILWAYS Specification of Letters Patent.

Patent/.1 Oct. 15, 1907.

vp tfltieu filed April 30,1907. Serial N2 371.]61.

To all u'liom. if may c mma:

Be it known that l. liot'ts II. Tlll'LLl-ZX. a citizen oi th United States, r siding at Edg w d Park. in the county of Allegheny and tate ot' Pcnnsylvania. havi invented certain new and useful lllll i t'tlll lll in nignaling Systems for Electric ltailways. i which the f llowing is a specilicatiori.

.\ly invention relates to signaling sy t ms {or el ctric railway and has for an object the prevent ion f an improper operat ion of a railway signal [or one track by the signaling current from an adjacent track. scribe a signaling system embodying my invention and then point out the novel features thereof in claims.

In the accompanying drawings. Figure i is a diagrammatical vi w of a portion of a double track railway, the rails of each track being divided by insulation to form block sections and all the track rails being included in the return circuit for the car propulsion current and having applied thereto a signaling system. emhodying my invention. Fig. 2 is aview similar to Fig. 1, but showing a modification oithesignaling system due to its being applied to a railway wherein an alternating cum-at is (ttlpltr \'t-tl for car pr pulsion purposes. Figs. 3 and 4 are each detail diaarat'uniatical views showing different forms of relays which may be used in the signaling system. Fig. 5 is a detail perspective view.

In Fig. 1 the signaling system is applied to an electric railw ay using a dir ct current for ear propulsion purposes. In Fig. 2 th signaling system is applied to an electric railway using an alternating current for car propulsion purposes. I have not illustrated the director alt 'rnat iug car propulsion systems in these figures as such syst ems are well known and understood in the art. Th r lays diagrammatically illustrated in Figs. 3 and 4 are applicable more particularly in signaling systems applied to electric railways using alternating current for car propulsion purposes.

Similar letters of reference designate corresponding parts in all of the figures.

Referring to the drawings, A, A, designate portions of two parallel railway tracks of an electric railway, each of which is dividedby insulated joints a to form block sections. As shown, both rails of each track are provided with insulated joints 0 to form block sections though, if desired, only one rail of each track may be so divided. Both arrangements are well known in the art. In Figs. 1 and 2, I have shown one block section X and portions of two others Y, Z. in one railway track, and one block section X and portions of two others Y,

Z, in the other railway track.

As the both rails of each railway track are included in the return path for the car propulsion currentand are suitably connected, one pole of the generator for the car propulsion current, which as stated, may be either direct or alternating, provision is made for conducting the propulsion cuirent around insulation points by means f reactance bonus.

I will d tn the drawings I have diagrammatically illustrated what. is known in the art as the "balanced type'ioi reaetance bonds. B designates such bonds. Th se bonds, it well known, comprise a core or winding all the turns of which are in the same direction and in close inductiv relation. Such a type of bond is set forth in L'. Patent No. 838,916, granted to me on D cember l 1906. In this type of head the pr wpulsien current is made to tlow through two equal parts of the winding or two windin s oi the some nuin her of turns in reverse directions, so that the propulsion current produces no magnetizing effect on the core,

III

- thus leaving the bond free to act as irnpcdances for the alternating signaling current of the track circuits. As shown. the windings of two adjacent bonds are connected by a conductor [1 or there may be a plurality of such conductors. (ross bonds b are also provided between the two railway tricks wher -v er possible, and they are for the purpose of reducing the resistance in the return circuit for the car propulsion current. In the drawings I have shown the cross bonds b as being connected with the conductors b of the two railway tracks.

The signaling system applied to the railway, comprises a railway signal or signals, for each block seclimit. and a track circuit for each block section to control one operation or the railway signal or signals. S, S, 3-. 5, etc., designate two railway signals which may he any of the well known types 0i automatic signals.

Each track circuit comprises a source of alternating current and a relay or relays. The source of alternating current let each track circuit is shown in the form of a transformer T, the secondary of which is connected with the track rails of its block section while the primary may he in multiple circuit with mains extending from a. suitable generator. The signaling current is preferably of a high frequency (6001' more cycles). The signaling current of the signaling system is of a. different frequency from the alternating propulsion current when the signaling system is applied to electric railways using alternating current for propulsion purposes.

Referring now to Fig. 1, each track circuit is provided with a relay R, but in addition to this relay R, a second relay R is provided to control the railway signal. The relay R is connected with the track mils of its track circuit in the usual manner and when energized by the alternating signaling current of its track circuit its vane r is moved to close contacts in the signaling circuit. The relay R, however, is normally deenergized, and its vane 1' is usually held h gravity or otherwise in such position to close its contacts in the signaling circuit. With no car or train i' a block section the apparatus will be in the condition illustrated and the signal device s of the railway signal will he in its clear position of indication. Should a car or train enter a block section, the wheels and axles thereof would short circuit the alternating signaling current from the relay R, which being denergized, its vane would move to open the signaling circuit and thus permit the signal device of the railway signal S to move to indicate danger. When the car or train moves out of the block section the relay R is again energized to clos the signal circuitv These operations are well understood in the art. It. will be ecu that the relay R had no part in the operations just described. Its only purpose is to open the signaling current in which it is included, should for any cause alternating signaling: curr nt from an adjacent track circuit tind a path through the cross bonds and conductors connecting the windings on adjacent reactauce bonds to the track cir--. ceit of relay R with which the relay R is associated. With normal or tlie'usual conditions existing under which the signaling system operates. the alternating signaling current for the several track circuits will be confined thereto and there is no tendency for it to flow in paths other than the track circuits. But suppose that a rail of one block section was broken. for example. at the point- 0 in Figs. 1 and 2: Alternating signaling current from the transformer T of block section X would then flow along the rail :1? to the bond B at tinleft oi the figures. Half the potential of the transformer would exi t at the middle point of the winding of the bond. and alternating signaling current. will flow through the adjacent cross bond b to the rails of block s-.-ction X. bond B at the right of block section X adjacent cross bond 1), bond B at the right of bloc'lt section X and the track relay R. imposing on this relay an electro-rnotive iorce which may be sufiicient to energize this relay should it have been shortcircuitcd by a train in its block section, thus causing it to move its vane and close the signal circuit. to have the railway signal clear with a train in the block section. To avoid this wrong clearing of the signal by this leakage current described. I have provided the relay R and the tl'thsir rmer P. shown in detail in Fig. 5). This transfc'iner or inductive apparatus comprises a laminated in 11 core P. and a secondary winding P" which is in circuit with the relay It. The core P is placed adjacent aconductor 1) as shown so that when the stray 0r leakage alternating current traverses the conductor b it will generate a current in the secondary winding P which causes the relay R to move its vane to open itt signal circuit. Thus. should a track relay be improperly energized by alternating signaling current from an adjacent track circuit the apparatus (transformer P and relay It) acts to open or keep open the signal circuit The relays R, R, may be substantially of the form illustrated and described in U. S. Patent No. 823.086. issued June 12, 1906, to me.

Fig. 2 illustrates the same arrangement of circuits and apparatus, but a different type of relay R for each track circuit and the same type of relay ll for opening th signal circuit should a foreign signaling current nter the track rails of the relay R with which it is as sociated. This relay per or forms no part of my invention, but is merely shown as a preferable type of relay in an alternating signaling system for railways using an alternating current for car propulsion purposes and the track rails as part of the return path. The relay comprison a substantially Wshaped core and an energizing winding on its middle leg. On one of its outside legs a closed conductor 1 is employed, which, when an al ternating current of high frequency traverses the winding on the middle leg exerts a counter-magneto force, thereby making the other outside'leg r a stronger pole to attract the armature. The armature of the relay R is balanced to close the signal circuit when no high irequen cy current is flowing in its energizing winding 1'". When the stray alternating signaling current traverses the winding on the middle leg, the armature of the relay R is moved to open the signal circuit.

Fig. 3 illustrates a further modification, the modification residing principally in the form of relay R. The relay is substantially like that illustrated in the patent liereinbefore referred to except that an additional core r and coil r is employed, which coil is in circuit with the transformer P. The core 1' and coil 1' are so arranged that when energized by a stray alternating signaling current it will move the vane r to open the signal circuit, or if the vane has moved to open the signal circuit it will act to hold the vane in that position as the same stray alternating signaling current will traverse both coils of the relay simultaneously. The coil T is in circuit with the track rails and this coil is used to move the vane r to close the signal circuit when energized by current from the transformerT. The normal operation of the relay R is the same as that described in connection with' the relay R of Fig. 1. The form of invention illustrated in Fig. 3 is applicable more especially to electric railways employing direct current as a motive power for the motor cars.

Fig. 4 illustrates a still further modification, the modification residing principally in the form of relay R The relay R is substantially the same as that illustrated in Fig. 2. In Fig. 2 two relays (R R are used whereas in Fig. 4 only one relay is used. The operation of the relay R" under usual conditions is the same as that described in connection with the relay R of Fig. 2; When a stray alternating signaling current flowsover the conductor 12 and induces a' current in the windin P of the device P, it magnetizesthe leg 1 of the relay by the winding 1 and causes the armature r to move to open the signal circuit.

Having thus described my invention, what I claim 1. The combination with two parallel tracks of an electrlc railway the ralls of each trackway being dlvlded to form block sections and are used to conduct car propulsion current to the generator thereof, of reactance bonds placed across the rails of each trackway, a conductor connoctlnz adjacent bonds in the same track-way, cross bonds between such conductors. a block signaling system for each track way employing an alternatlng signaling current in the track circuits of the signaling system. means adjacent the said conductors in which a current is induced by a stray alternafln: signaling current flowing over such conductor. and means affected by sald induced current for opening a signal circuit.

2. The comblnatlon wltltwo parallel tracks of IV] elec' tric railway the rails of each trackway being dlvl-led t form hlock sections and are used to conduct car: propulsldu current to the generator thereof, at reactance bonds p aced across the rails of each trackway, a conductor connecting adjacent bonds in the same trackway. cross bonds between such conductors. a block slgnallng system tor each track way employing an alternating signaling current In the track clrcults of the slgnallng system, means adjacent the said conductors ln which a current ls Induced by a stray alternating slgnallng current flowing over such conductor, and a relay affected by said induced current for opening a signal circuit.

10 adjurcnt the said conductors in which a current is induced by a stray alternating signaling current flowing over such conductor, and a relay affected by said induced current for opening a signal circuit.

In testimony whereof I have signed my name to this specification in the presence of two subscribed witnesses. 15

LOUIS H. THULLEN.

Witnesses: ELMER R. Con, DANIEL J. MCCARTHY.

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