US1016922A - Railway signaling system. - Google Patents

Description

L. V. LEWS L I. S. HOLLIDAY.

RAILWAY SIGNALING SYSTEM.

APPLIGATION FILED JULY 7, 1911.

l L. Patented Feb.6,1912.

ne it tj GHS T THE UNON SVHTGH z SEG-NAL GOMPANY, 0F SNSSVALE,

'Lewis end ,izens or the United *ftiveljg et Ld ffewood the county or fille- Pennsy Vania, have inend .useful improve om* is specification.

- relates to epparetus'ior use current signaling systems Ways both et the lines of ,hich cre included in the path renti. More pcrticufrom the seine g drewi' g is it diagramtc'o e portion o an electric ed 'thereto e signaling rswing, 'L designates ic railway the 'track ded by insel-ations 4; 'n n, it is un: ,e f3 he lince of track rails e c cenit forthe propu i is must be provided propulsion current fils' here shown,

' eens comprises inductive bonds t3, lei, i6, which bonds are p eersloly el? Ke shown find described in United i ters Petenthlo. 838,916, granted Thollon on Dec. 18, 190. Briefly each these bonds comprises e iron core upon which :ire Wound sevterr err electric conductor. The

et the bonds are contrziclt rails edpropulsion current in its passage through the Winding of each hond iloWs in "e ends and out at the middle point, er the middle 'point and out et the ends, hf t therefore it' the iiow of propulsion current is equal in the two lines ot rails, the

Sijoccication ci' Letters Fateci.

, Patented 3, itali?,

eerzal re. @7369.

iron core of the bond will not loe megnetized by this current, Hence the bond Will not be inductive to the propulsion current when the propulsion current is alternating. But since the alternating signaling current, hereinafter explenedytends to liow through the winding' of each hond from end to end, the bonds will he inductive 'to this currenty and therefore impede the ioW of signaling current from one line of rails to the other.

We here not shown the genera-tor for the propulsion current nor the remainder of the circuit for the propulsion current; these elements are so Well understood as to require no further illustration or description.

Each lclocl section is provided with e track 4circuit coinprisingcs usual the track rails (or portions of there) of the block section, e source of signaling current, and e relay. As here shown, the source of current for two acent block sections, for example block sections A and B, is a. transformer 5 Whose primary 6 is connected With a source 8, 8, designate relays for the block sec- @tions A and E respectively, which relays may he of any desired t-yge which will respond to the signaling current :md not to the propulsion current in their normal or usuel con trol. olf their signals.

S, S, designate rail my signals, controlled by relays En", S, in :L usual nd Well known manner..

included in each track circuitlhetween the secondary of the transformer-"end the track rails is u, resistance, which hay he either inductive or non-inductireln ,the ficcoi'npenying drawing, ll is the resistance i'or the track circuit of block section A, and l2 is the resistance for the track circuit of block section B. These resistcnces may be employed to limit the discharged signaling current from 'the transformer secondary when the track mils of e, block section are occtmiecl` hy cer or train, or they may he employed to aiiect the phase of the signaling current supplied to the relay by the track circuit, or they may be employed for both ol these purposes or for other purposes. l

As shown in the accompanying drawing, the resistance 11 (ron-inductive or inductive) in the track circuit of block section A. is divided into two substantially equal portions 11"L and 11b, one of which portions is included in each of the two leads between the transformer secondary and the track rails. Similarly, the resistance 12 tor the track circuit of block section B is divided into two substantially equal portions 12a and 12b, one 'of which is included in each of the leads between the transformer secondary and the track rails. With this arrangement, there will be no iiow of current between the middle points of bonds 13 and 14, even when the total resistances 11 and 12 are unequal, for the rea son that these middle points will always have the same potential, and this potential will be the same as that of the middle point of the transformer secondary 7. lhis is evident, from the fact that the circuit between. each terminal of the transformer secondary and the middle point ot "ach oi' the bonds includes a half winding the bond and a half of the total resistance 11 or 12. With a car 17 in block section B as indicated in the drawing, although the bond lt will be shunted by the car, the potential of the middle point ot this bond will still be equal to that of the middle point of the secondary .7 for the reason that there yare equal resistances 12l and 12b between thcterminals of the secondary 7 and the middle point of bond 141. Hence the two track circuits will be entirely free from interference with each other, regardless of whether or not one or the other or both are occupied by a car, except for such slight action as may occur within the windings of the trans-- former.

It is often advantageous that the resistances 11 and 12 should be inductive. When such is the case, the two portions 11 and 11b are preferably in the form ot two coils wound on one magnetic core 19, and the two portions 12a and `12b are preferably in the form of two coils on another magnetic core 20, as illustrated diagrammatically in the drawing. With this construction, the total impedance of either pair of coils 11 or 12 vmay be varied by varying the reluctance of the common magnetic circuit for each pair, the impedance of the two coils on each core being always equal. The coils are connected with the track rails and with the source of signaling current in such manners that the 4magnetic iuX induced in each core by signaling current flowing in the two coils ,Wound thereon will be all in the same direction, so that the coils are inductive ,to the signaling current; but that the magnetic ilus induce.dI

by propulsion current in the two coils will be in opposite directions and will therefore be neutralized, so that the core will not be magnetized by the propulsion current2 and so that when the propulsion current is alternating its tlow will not be impeded by the windings. This arrangement of the coils will be readily understood by reference to the accompanying drawing.

When the coils 11a, 11b, 12a and 12b are connected as just described, they will automatically compensate for conditions caused by unbalanced propulsion current inthe two lines of rails. When unbalancing occurs, that is, when more propulsion current flows in one line of rails of a block section than in the other line of rails, there will be more propulsion current in one Vhalt of the winding of the bonds 13, 14, 15 and 16 than in the other half, and consequently the cores of the bonds will become magnetized. This magnetization will lower the impedance of the bond to the signaling current, allowing more signaling current to flow through the bond and thereby having a tendency to reduce the voltage of the signaling current at the relay. But at such times, the flow of propulsion current in the two coils on each core 19 and 20 will also be unbalanced, and the propulsion current will magnetize' these cores, thereby reducing their impedance 'to the signaling current and increasing the voltage of the signaling current impressed on the track rails. The voltage of the signaling current at the relays will thus be maintained substantially constant in spite of unbalancing of the propulsion current.

Having thus described our invention, what we claim is:

1. In a railway signaling system, two adjacent block sections, a source of alternating signaling current, a transformer whose primary is connected with the source of alternating signaling current and whose secondary is connected across the track rails of both block sections, andtwo substantially equal resistances connected respectively between the transformer secondary and each rail of one of the block sections;

2. ln a railway signaling system, two adjacent block sections, a source of alternating signaling current, a transformer whose primary is connected with the source of alternating signaling current and whose secondary is connected across the track rails of both block sections, and two substantially equal resistances connected respectively between the transformer secondary and each rail of one of the block sections, and twd substantially equal resistances connected respectively between the transformer secondary and each rail of the other block section.

3. ln a signaling system for electric railways the track rails ol' which are included isa (gli

lli-

nordsee in the circuit for the propulsion current, two adjacent block sections divided by insulation in` the track rails, means for permitting4 propulsion current to ilow trom the rails of either of the said block sections to the rails of the other block section, a source of alternating signaling current, a transformer whose primary is connected with the source of signaling' current and whose secondary is connected across the track rails of both of said block sections, two substantially equal resistances connected respectively between the transformer secondary and each rail of one et the block sections, and two substantially equal resistances connected respectively between the transformer secondary and each rail of the other block section.

in a signaling4 system for elect-ric railways the track rails of weich are included in the circuit for the propulsion current, two adjacent block sections divided by insulation in the track rails, means for permitting propulsion current to dow from the rails of either of the said block sections to the rails of the other block section, a track circuit tor each block section each 01" which track circuits includes the opposite lines ot' rails of the block se tion, a source of alternating signaling, current, a transformer whose primary is connected with the source ot signalcurrent and whose secondary is connected acrossl the track rails of both. of said block sections, two substantially equal 4resistanees connecten respectively between the transformer secondary and each rail oi.3 one of the block sections, and two substantially equal resistances connected respectively between the transformer secondary and each rail of the` other block section.

5. in a. signaling' system for electric railways, the track, rails of which are included in 'the circuit for the propulsion current, two adjacent block sections divided by insulations. in the track rails, means for permit-- ting the propulsion current to flow from the rails of either block section to the rails of the'other block section, a source of alternating` signaling current, a transformer having 'its primary connected with the source of signaling current and its secondary connected across the track rails of both block sections, two substantially equal inductive resistances wound in the same direction on one magnetic core and interposed respectively between the secondary and each track rail of one ot' the block sections, and two substantially equal inductive resistances wound in the same direction on another magnetic core and interposed respectively between the metil secondary and each track rail of the other block section.

6. .in a signaling system tor electric railways the. track rails of which are included y in the circuit for the propulsion current, two adjacent block sections divided by insulation in the track rails, means rfor permitting the propulsion current to tiow from the rails of one block section to the rails ci the other block section, said means comprising an .inductive winding connected across the opposite rails of each block section, and conductor connecting the middle points ot the said windins, a source of alternating signaling current, a transformer whose primary is connected with the source of signaling,- current and whose secondary is connected across the track rails of both block sections, two substantially equal resistances interposed between the secondaryand each track rail respectively of one of said block sections, and two substantially equal resistanccs interposed. between the secondary and each track rail respectively of the other block section.

7. l'n a signaling system for electric railways the track rails of which are included in the circuit for the propulsion current, two adjacent block sections divided by insulation in the track rails, means for permitting the propulsion current to flow from the rails of one block section to the rails of the other block section, said means comprising an inductive windingr connected across the opposite rails of each block section and a oonductor connecting the middle points or the said windings, a source of alternating signaling current, a. transformer whose primary is connected with the source of signaling current and `whose secondary is connected across the track rails of both block sections, t-wo substantially equal inductive resistances wound in the same direction on one magnetic core and interposed respectively between the secondary and each track rail of one of the block sections, and two substantially equal inductive resistances wound in the same direction on another magnetic core and interposed respectively between the secondary and each track rail of the other block section.

In testimony whereof we atx our signatures in presence of two witnesses.

LLOYD V. LEWIS. JHN S. HULLIDAY l/Vitnesses:

CnAs. E. McCoy, C. R. BEALL.

Sill

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