US1056993A

US1056993A - Alternating-current track-circuit signaling.

Info

Publication number: US1056993A
Application number: US???1?711A
Authority: US
Inventors: Winthrop K Howe
Original assignee: General Railway Signal Co
Current assignee: SPX Corp
Publication date: 1913-03-25
Anticipated expiration: 1930-03-25

Description

I W. K. HOWE. ALTERNATING CURRENT TRACK CIRCUIT SIGNALING.

APPLICATION FILED SEPT. 30, 1911. 4

1,056,993, 1 Patented Mar. 25, 1913.

4 BKBETS-SHEET 1.

- WWI-M58858: I i nwmron I I 0% 7 W71 7441K 2 E 2 Z BY ATTORNEY W. K. HOWE. .ALTBRNATING CURRENT TRACK CIRCUIT SIGNALING.

Patented Mar. 25, 1913. I

APPLICATION FILED SEPT. 30,1911 1,056,993.

4 SHEETSSHEET 2.

W INVENTOR ATTORAIFV WITNESSES:

W. K. HOWE.

TRACK GIKCUET SIGNALING.

ALTERN ATING 0 URRE APPLICATION FILED SEPT. F10, 1911.

Eatented Mai. 25, 913.

t PIN i Milan xi! W. K. HOWE; I ALTERNATING CURRENT TRACK CIRCUIT SIGNALING.

APPLICATION FILED SBPT.30,1911.

Patented Mar. 25, 1913.

4 SHEETS-*SHEET 4.

.i m II mw. 7v

INVENTOH ATTORIV WI TNE88E8: M

lilting joints used in track circuit signr ii'llln' 'lT/INTHROI K. HOWE, 033 new SIGNAL COMPANY, 0 E

Application T0 and whom it may concern 5 Be it knownv that l, WINTHRoP i a citizen of the United States, of the city of Rochesteryin the co Monroe and State of New licrh; rented a new and useful Ethernet rent Track-Circuit Signaling, of Wli following is e specification.

This invention relates to track e ncling and especially to alternating; track circuit signaling.

One object of this invention is the normal consun'iption of energy in. s. t circuit to a minimum;

Another object of this inventi duce the maximum energy consuin minimum.

As is well understood by those s ii the art, the greatest amount ensupplied by the Well known 'trac former used in alternating current t cuit signaling when the transforme the track are practically shortcirc the presence of a train upon the tree. such point.

It is an object of this invention tere: the energy consumption under such so tions to a value much less than the norm consumption of energy by the rack circui A further object of this invention nullify the extremely bed results cause.

the short circuiting of the well know" and to thereby obtain what is tech known as broken down joint projectio Insulating joints in tracks are n source of annoyance, but. as yet no u practical scheme of track circuit Without them has been thoroughly periec so that they must at present he endured. is necessary, however, to provide against danger caused by the breaking down short circuiting of such joints. The dz. resulting from such breaking down in the fact that the electrical-energy in track circuit section is liable to falsely op ate the relay in the next section. Such. on ation may result either in holding a, signal danger when it should be at clear or holding a signal at clear when it sheu at danger. The first of these is tremely annoying and would cause tll'l lay to traffic; the second is or such 2,

-' switclia operated by the signal controlling the track circuit section in advance so that in one po'- sition of said signal the pole changing switch will be in such a position as to cause current to be fed to the track circuit section in the rear having a difference of phase one hundred eighty electrical degrees removed from the phase of the current supplied to the track circuit section when the said signal and consequently the pole changing switch are in another position. By employinga relay which will assume a central position when no current flows therethrough and which will close a contact on one side of the center when current of one phase relation flows therethrough and which will close a contact on the other side of the center when current of the other phase rela- 1 whether they are of like polarity or of un-' like polarity when thejo-ints break down for either the relay of one section" or the current supply of the adjacent section will be short circuited, consequently, the relay in one section or the relay in 'the other will move to the central position and cause a false danger signal, thus attracting immediate attention to the defect. It must be readily seen that the method of transposing the connections from the current supply to the track circuit in alternate sections would not provide for broken down joints in a three position polarized relay scheme of signaling. If the joints should break down there would be at times a current in the adj acent section of the proper polarity to actuate the relay to' cause a false clear signal. The third method although applicable to a three position polarized relay scheme of signaling introduces other complications which at present it is not desired to introduce, in the way of a larger number of parts in the insulating joint. Although a diagonal bond scheme of broken down joint protection in a polarized relay track circuit system of signaling thus appears to be the .most practicable method to use, it has manifest disadvantages. One disadvantage lies'i'nthe fact that with a steam road system a path for any foreign current which may be present at any part of the line is formed, wliiclr'allows the current to flow unimpeded the full length of the line, and as at present most foreign currentis of the direct current type, and may fiow through the track relays, causing a magnetic saturation of the magnetic stator and so causing a slowing of the rate of movement of the rotor, it is necessary .vhen

diagonal bonds are used to so construct the relays that they are immune to the effect of direct current, as for instance by the method fully shown, described and claimed in the application of Oscar A. Boss and Anthon H. Vogt, Serial No. 593,673, filed November 22nd, 1910. Another ditiiculty of greater moment is the fact that with road ballast having a low insulation resistance the leakage of current from one track circuit section to another track circuit section in another track as on a double track road may in wet weather amount to suiiicient to wrongly op erate the track relay in the track to which the leakage current flows, and might under extreme conditions cause a false clear signal, as such a construction increases the tendency for leakage.

Polarized track circuits have not only the difiiculties above mentioned, but also the diiiiculties incident to ordinary track circuits, to-wit: a large normal energy consumption due to the fact that a resistance must he placed in series with the track leads from the energy supply in order to limit the current flow to a safe value when the track leads are short circuit-ed as by a train standing on the trackat the point of connection. As a-train may short circuit the track leads for a considerable length of time, a means must be provided to dissipate the heat generated in the resistance, consequently it has heretofore been necessary to form such resistance into cast iron grids of a non-inductive construction and to place the same at some point close to the track in a box, to which the outside air has free access, thus forming an undesired and sonic times unsightly obstruction on the right-ofway. Applicants invent-ion obviates the necessity for resistances and heat dissipating structures and so removes another of the objectionable features of alternating current track circuit signaling. The use of a resistance in series with the track leads also obligesthe use of a higher electromotivc force than wouldptherwisc be necessary, in order to cause the necessary current to How in the track circuit to operate the relay, thus increasing the normal energy consumption. As applicants invention limits the value of the maximum current flow in the track circuit to far below the value which it attains in systems as installed, it allows the use of smaller conducting members between the energy supply and the track and so etfects a much desired economy of high priced material, and as a series of track circuit sections would consume very much less energy than present systems, the line wires from the'central stat-ion supplying energy to all of the track circuit sections could be much reduced in size thereby effecting another economy. The generator at the corn tralstation could also be smaller and conmesses sequently much less erpensive in first cost and to install and to operate. In order to explain the principle of the invention, and to describe the mode of operation and construction of the particular physical embodiment of the invention se-' 2 diagram, similar to Fig. 2, showing the systern as applied to a steam propelled road. 4, is a diagrammatic view of a wireless automatic block si shows the construction of one of the improved elements ot'my system, to-witr the so called automatic reactance.

Upon the base 1 is fastened the M shaped member 2, composed of thin sheet iron laminae. The post 3 rigidly attached to the base' 1 has an upper bifurcated end through which extends a pivot pin 4- supporting a lever 5, having on one end an adjustable weight 6 and having the other end formed into a hook 7. The hook 7 passes through the eye of a rod 8, which is fastened to the center of'a ll shaped rod 9, thelower ends of the U shaped rod each being fastened to a plate of non-magnetic material 10 having a central cut-away. portion' ll in order that the plate may pass over the middle limb of the M shaped memberii. A. coil of insulated conducting wire 12 preferably made of copper is Wound about both limbs of the: U shaped member 9. and is supported by the plate lO, the ends of the coil'being attached to the binding posts 13 and 1A. If the coil 12 ,is connected in series-with a source of current of constant electromotive force .and

an adjustable resistance, with the resistance so adjusted that not more than a certain predetermined uantity of current flows through the coil there will be no bodily movement of the coil, but if the quantity of current flowing through the poil is increased by cutting out resistance, the magnetic field produced by the current flowing in the coil 12 will, in its endeavor to flow through the path of least reluctance draw the coil downward upon the middle limb of the M shaped member 2, overcoming the torque produced by the weight 6 to hold it in its normal position as shown in Fig. l. A gradual removal of the resistance in series with the supply of current and the coil 12, will cause the coil 12 to be drawn lower and lower upon the middle limoof the member al system. Fig. 1,-

2, but the downward movement is resisted by a greater and greater torque exerted by the weight 6 as it is apparent that the weight 6 as it moves upwardly to a horizontal position exerts a greater and greater torque this torque being proportional to the increasing torque of the coil 1221s it is drawn down farther and farther upon the middle limb of the member 2. In practice the device is so designed, however, that a very slight increase of current is required to start the coil 12 to moving downward. As the coil moves downwardly upon the middle limb of the member 2, the reactance of the coil to alternating current is gradually increased. The increased reactance in the coil caused by its movement downward upon the middle limb oil of the member 2 is a phenomenon well understood by those versed. in the electrical art. As the reactancc of the coil increases, the some electromotive force which caused the normal predetermined current to flow in the coil would necessarily cause less current to How in the coil, but if at the same time the adjustable resistance in series with the coil and the source of current were graduallyw'nade less and less by the same amount, the same electromotive force which caused the normal predetermined quantity to flow through the coil when in its upper position would still cause the same predetermined amount of current to flow. It is to be observed that although the current in the coil remains the same, the electromotive force across the terminals of the coil changes, for

I the drop of potential which formerly existed across the adjustable resistance has now been transferred across the terminals of the autoniatic re'actance thus largely increasing it. The increase in the reactance of the coil results in an increase in the apparent resistance or impedance and also results in a dis placement of the phase of the current so that it lags a greater or less extent behind the electromotive force, therefore, the power factor of the circuit is changed. In the case ot' thecoil just described, as the reactance increasesthe ohmic resistance of the 0011, re-

maining the same, the cosine of the angle as shown upon a system of rectangular cotirdinates between an abscissa and a line representing the phase of the current when the coil is drawn downward to its greatest extent is much less than the cosine of the angle between the same abscissa and the line representing the phase ofthe current when the coil is in the position as shown in Fig. 1, consequently, as the power factor is proportional to the cosine of such angles it is very much greater when it is in the position as shown in Fig. 1,-and so closer to unity. It is also to be observed that as the power fac- 36idecreases,'uncler such conditions the current is displaced in phase more and more as the coil is drawn down upon the middle limb of the member 2 as the ohmic resistance remains constant but the rcactance ot' the coil changes.

' About the coil 19 is placed the copper annulus which is rigidly simported in the fixed position shown in any approved manner. As it may be possible that the power factor of the coil 12 when in the upper position as shown in Fig. 1, is too low, it may in some cases be necessary to raise it which may be done by placing the copper annulus 15 so that when the coil is in its upper'position it will be surrounded by the annulus. Under such conditions an alternating cur rent flowing in the coil 12 will generate a current in the annulus 15 which will react in the well known manner upon the coil 12 to 'reduce its reactance and thus the ohmic resistance of the coil remaining; the same, increases the power factor and as the power factor is' increased by a change in the reactance only. the current will be brought nearer in phase with the electromotive force. in the great majority of cases it will probably be unnecessary to use the annulus 1:7, it being merely shown and described to illustrate the most perfect embodiment of applicants invention making it applicable to the most extreme condition.

Upon the front and back faces of the lid shaped member 2 the limiting stops it; and. 17 are adjustably mounted, being held in adjusted position by screws as 18. r As the coil 12 is drawn lower and lower upon the middle limb of the M shaped member '2, the reactance gradually incl-uses and the power factor gradually decreases and the current is displaced in phase more and more as the coil is drawn down upon the middle limb of the member 2 as heretofore pointed. out, but in some cases it may be undesirable to have the coil drawn entirely down upon the middle limb of the member 2. thert'ore the ad justable stops 16 may be used to prevent the coil mo'ving down too far, for in some cases it may be advisable to prevent the great-a dec ease in the power factor of the circuit contztining, the coil 12 and tlnis prevent too great a displacement of the phase of the current therein.

Referring toliig. 2, 10 and 20 designate the two rails of an electrically propelled road, separated at intervals by the insulatinf} joints 21, thus forming blocks each of s which is governed by a. signal as 22 or 23 at the entrance tlmrcol A generator Qt is lo rated as is customary at one end of the line. one terminal of which is connected by the Wire 25 to a central point of the winding upon the well known iron core track reactance bond 26, the two ends of which are connected as at 27 and 28in the two rails or" block at one end thereof. ill the other end of the same block and at the beginning of the next adjacent block similar iron core reactance bonds are placed connected in the usual and well known manner and at the meeting points of all of the subsequent blocks reactance bonds are likewise connected, thus furnishing an unimpeded two rail return for propulsion current from the wheels 29 of an electrically propelled car 30 to the source of current 24 at the terminal station. The motor 31 of the car 30 is con nectcd by one terminal to the axle 32 upon which the wheels 29 are placed and the o Lher terminal connected by means of the trolley pole 33 to the trolley wire 84- which is connected to one terminal of the generator 24: at the terminal station.

A. source 35 of alternating current is located at the central station and is connected to the two line wire. 36 and 37 (attending the length of the track-way At suitable points the primary windings of the transformers 3S and 39 are connected to the line wires. The secondary winding 10 of the transformer 39 supplies the two position signal 29 with current through the wire 41:1, point 42, contact arm 44' and wire 4:5, and also supplies electrical energy LO one winding 1-6 of the relay. The relay of the well known polyphase type having two windings l6 and t7 and a shell rotor 48 hearing the contact arm l4: whicln when the relay is energized is adapted to bear against the contact 42. The secondary winding 4-9 of transformer 38 through the wire 50 connects to one track rail 20 and by means of wire 51 connects to one end of coil 1 upon the automatic reactance device and from the other end of the coil 12 connects by means of wire 52 to the other rail 19 of the trackway, thus supplying en ergy to the track circuit. At the other end or the block section thus supplied with energy, one wire 53 connects with one rail 19 and with one end of winding 4-7 of the relay and another wirehlconnects with the other track rail 20 and with the other end of windingr l7 oi the relay.

Aside from the automatic reactance device the system asshown in Fig. 2, is constructed and would operate exactly the same as the common and well known forms of alternating current block signaling systems, that is to say the presence of a train upon either block section B r C would cause in the well known manner the signal such as 22 or 23 governing the entrance to said block to move to the danger position. By the use of the automatic r-eactancc, however, the various ol' jects herein bet-ore stated are attained.

in ordinary systems in place of the coil 12 between wires 51 and .79 a non-inductive grid resistance is inserted so that in order to produce thenccessary available drop of pontial across the terminals of wires 5?} and 5% at the points where they are connected coil 49 ofthetransformer 38 than would otherwise be necessary, consequently, the

normal consumption of energy in such a track circuit is greater-than oneinwhich the coil 12 is in series with

wires

51 and 52, as the'co'il 12 as constructed by applicant is of a great deal lessohm'ic resistance than the non-inductive grids as ordinarily used,

therefore, the normal consumption of energy,

bya trackcircuit section is decreased.

As' the purpose of the non-inductive grid resistance is to limit-the 'amou'nt' ofcurrent I which may flow when the wheels and axles ofa car bridge the terminals of

wires

50 and 52 and as at; times' a car may remain -in such a position for a great lengtlrof time, the

resistance grids must be of a;size to properly limit the. currentand at the same time be so constructed and installed as to dissi- 'patethe heat generated by the flow of current through them under the most adverse conditions, at the same time,their resistance must'be of as low a praticablevalue as possible in order to, decrease as much as possible the normal energy'consumption of a track e rcrut-sectronQ It ls nipracticable to so design a non-Inductive grid resistance that. the amount of "current flowing when the terminals of wire E50 and 52 are short circuited by. a trainis'ho greaterthan the amount of. current flowing when no train is prsentuponthe track circuitsection. ,fln fact there is an enormous (inference-between; the amount of currentflowing under normal conditions-and the amount flowing upon the short --circuiting ofthe -

wires

50 and 52 so that the consumption of current by a track circuit section 'under abnormal conditions is I very great By the insertion of the'automatic reactance inseries with

wires

51 and 52. the presence of a train across the terminaisof wires --and 52 causes the coil 12 to be; drawn down upon the middle limb of themei'nberfl, as shown in Figs. 2, 3 and 4,

and-as it is} drawn down upon'the member 'L2- the impedance of the coil 12 is increased and the coil-l2jmay be so -designed by principles well known to electrical engineers .that the current flowing through coil 12 will be the same whether a train is present, short tcircuiting the terminals of

wires

50 and 52 or whether no train is'present, the train and the track rails-taking the-place of the adjustable resistance heretofore. described in connection with the-coil. As soon as a train which has short circuited the terminals of

wires

50 and 52 passes on, the weight 6 re- Qeo turns the coil to its initial position.

As thecoil 46 upon the relay is connected directly,- to the secondary 40 of, the transformer39 and as it is wound upon the magnetic stator, of. the motor, it is as'ordinarily constructed highly reactive and consequently the power factor is low and the current is displaced in phase from the-electromotive force by a considerable electrical angle. In order to get good operation of the relay it is therefore necessary that the current flowing' throughwinding 47 of the relay be dis. placed as little as possible in phase from the electromotive force. With the connections from the secondary 49 of the transformer 38 throughthe automatic reactance 12 to the track-rails 19 and 20 as herein shown, the circuit containing winding 47 has a high power factor. This is so because the ohmic resistance of coil .47 is a very small fraction of the ohmic resistance of coil 46 and because the reacta'nce in the circuit including winding 47 is both very much less than the reactance in the circuit including winding 4:6,- and the circuit including the winding 47 is furthermorehighly resistive. The current flowing through winding 47 is therefore more nearly in phase wit-h the electromotive force. By reason of such facts a ood difference of base between currents in

windings

46 and 47 is maintained thereby resulting in a good torque in the relay. \Vith the arrangements and constructions as shown by Fig. 2 if the insulating joints 21r-should become siort circuited a current would flow from the rails of one section to the; rails of thenext section and so through the track winding of the relay. It must be readily understood that an operation of the relay would result, if the current thereby reaching thetrack winding of the relay was displaced in phase, from the current flowing in the local winding of the relay as 46. As-heretofore pointed out, an operation of the relay under such conditions is objectionable and in some cases absolutely dangerous and heretofore, in order to provide against such difiiculty as already pointed out, connections from the line wires to the track from the .supply of energy have been transposed in adjacent sections thus causing an operation of the relay under such conditions of broken'down insulating joints that will result in a danger signal not in a clear signal. As' heretofore pointed out such a method is not applicable to the so-called alternating current polarized track circuit and recourse has been had to the diagonal bond heretofore mentioned but the actance device exactly as does the presence of a train short circuiting its terminals so that the movable coil thereof is drawn down upon the middle limb of the iron member, the reactance of the coil is largely increased and consequently the current flowing there through is largely displaced in phase from that of the electromotive force so as to lag considerably behind the same. As has already been pointed out the current which is caused to flow through the track winding of the relay in order to produce a good rotation of the relay is displaced very slightly in phase from the electromotive force, consequently the current which flows to the track phase of a relay from an adjacent section when the joints break down, does I not have the proper phase relation as re gards the current flowing in the local phase of the relay to produce the rotation, for,

the current flowing through-the track winding of the relay, under such conditions is or can be made to have the same phase displacement from the eleetromotive force that the current flowing in the local winding of the relay has.

In Fig. 4 has been shown a three position automatic signal system employing no line wires, that is, a system ordinarily known as a wireless system. In its broad features it differs from the'system as shown in Fig. 2 merely by the means used to obtain the third position of the signal, to-wit: the pole changing switch designated generally by S. This switch is inserted in the leads from the track transformer and the automatic reactance device to the track and is actuated by the movement of the signal blade, so that when the si al blade is in the full clear or90 position the switch will make the same contacts that it is making as shown at S, but when the signal blade moves below the 45 or caution position, the switch will make the contacts as shown at S. Considering that at a certain instant positive current starts from the right hand end of transformer 38 in section A, then the current will flow by means of wire 50, arm 55, contact 56, wires 57 and 58 to the lower track rail 20, and the return current will flow from track rail 19, through wire 59, contact 60, arm 61,

wire 52, reactance coil 12, and wire 51 to the from that of switch S, on' account of the fact that the signal .23 has its blade at the danger position, but if the switch had not been moved but were in the same position as switch S, connected with section A, then the lower rail instead of being of positive I polarity would be of negative polarity. The polarity of the rails with the parts as shown is indicated by the usual polarity signs at the connections of the

wires

58 and 59 to the rails 19 and 20. The polarity of the rails in section C, with the switch S as indicated, will be the same as that in section A. It must be readily seen, that the polarity 0f the rails in adjacent sections with all signals at clear is reversed so that abutting rail ends separated by an insulating end post will beof different polarity throughout the system, consequently any breaking down of the joints, while all signals are at clear, would act upon the relay exactly as does thebreaking down of the insulating joints in the case of a system connected as is shown by Fig. 2. Even if by direction opposite to that which would cause the signal to go to the clear position and so such a movement could only cause the signal to move to the 45 or caution position. The circuit in which current flows to cause the signal to move to the 90 posi tion is as follows: secondary 40 of transformer 39, wire 41, signal mechanism wire 63, relay point 42, relay contact bar 44, wire 45 to the other terminal of the secondary of the transformer. current flows for the 45 position. is wire 41, connected to the secondary 40 of the transformer 39,

signal mechanism wires

64 and 65, e'onta t point 66, contact bar 44, and wire 45 to the oth r terminal of the transformer. It will be observed that connection is made to wire 64 and to the negative terminal of the transformer when the contact arm 44 is in a position to cause cur- .rent to flow through the circuit to move the signal to the full clear position. This is the The circuit in which L censee ing the signal blade from the zero or danger when the signal blade is in the zero or danger position and as soon as the connection were made to move the signal blade to the position, no movement at all of the signal blade would take place as it must on account of the construction of the operating mechanism be first moved to the 45 position before being moved thereafter to the full clear position by the current flowing in the full clear circuit. A car 30 is shown upon the rails of section C, consequently current is shunted from the track winding oi? the relay and the contact arm 44 moves to the central or neutral position and in so doing, breaks both the caution circuit and the full clear circuit, so that the signal moves to the danger position as shown, and also moves the pole changing switch S to the position as shown, reversing the polarity of the current ordinarily supplied to the track section B, consequently moving the Contact arm 44: from its normal position from contact with

contact points

42 and 67 to n position in contact with contact point (36 as shown, thus causing the signal blade attached to signal 22 to move to the 4-5? or caution position as shown. With the'signal 22 at the cantion or 45 position. caused by the movement of the pole changing switch S the polarities of the abutting rails at the in sulating joint at signal 22 will be the same, consequently, the occurrence of a broken down joint at such a time would not result in a full clear signal, for even if the cur rent passing through the automatic reach ance device in section A. were out of phase with the current supplied to the local wind ing of the track relay in section B, any movement which tool; place would be in the same direction as that caused by the current in the section itself. If the insulating joint between sections B and (l were broken down and the phase of the current passing through the automatic reactance device connected to section B had not beenexactly balanced with the phase of the current ,tlowingthrough the local winding of the relay' in section C and enough movement of the contact bar l l of the relay connected to C had been caused to complete the circuit for the 45 indication, then upon the approach of a train, the current would all he shunted through the wheels and m of the train and the relay attached to the rrils of section G would be delinergized and the "ignal would go to the danger position and .ir t train had passed the insulating joint and gone i it did upon the rails of section C, the signal ivould still remain at danger, for although the phase of the current supplied to section B through the automatic reactance device might be under unusual conditions slightly displaced from the current supplied to the local Winding of the relay C, it would never be so largelydisplaced that it would be able to cause sufficient movement of the contact bar of the relay in section C to close the contacts after the relay had once been brought to rest, and especiallyavhile a shunt was present, caused by the presence of a car upon the rails to which it is attached Whenever the insulating joints break down between two sections as between sections B and C with no train present, the signal governing the advancesection as 23*will be placed to danger and at the same time the signal governing the rear section as 22 will, also be placed at danger for the path of low resistance furnished to the current from the automatic reactance device 12,connected to section B -causes the coil 12 to be drawn down so far ,upon the middle limb of the member 2 andthe reactance of the coil thereby so largely increased, that the phase of the current supplied to the track winding of the *relay connected to section B is so largely displaced from normal and ap proaches so closely to the phase of the current supplied to the local winding of the relay connected to section B that suiticient torque is not exerted upon the rotor of the relay to hold the contact bar it in the very extreme position. Even if the current supplied to section B should teach the track winding of the relay connected to section G and even it it should he disolaced in phase sutticiently to operate the relay, no dangerous results could flow, for the direction in which'thc contact bar 44 would be moved, would be toward the central or neutral position as the polarities would be opposite in the two sections,.consmpiently, the i to danger, butlas soon it did no to danger the pole Chang switch S5 would he changed to the EJOSlLJdll shot 4, thereby reversing the polarity c rent supplied. the ra the current would ilo: to the relay co a direction to c the 45 or so 7 again revs ac current 2 g i the total r a: of the sig' being I x from the degree position to. the sition ltis to be observed the "oplication of the automatic react ace device to'a poial would hing, so that the si nal l'arized track circuit, just as in the of its application to an unpolariacd track circuit, does not necessitate any connections which are at any time idlc in the normal working of the system, consequently a poor connect-ion or e broken connection wlich would d stroy the eiiect of the protective apparatus would also so disturb the normal operation of the system that the signal atfcctcd thereby, which would under broken down insulated joint conditions be affected by the automatic reactnnce 1 evice, would be moved to the danger position Although applicant has herein shown and described his new and useful means in connection with what are or inarily tern d two rui track 'cirt it is obvious to those ski t the new and useful means describe by "int are equally applicable to any form. of rail circuits and applicant considers that the zunilication of his novel, and useful means to the so-called single rail track circuits, is well within his invention; i

As the power .actor of the circuit i :lud ing the auton'iatic reactancc device do creased by short circuiting the terminals of its coih there is no large increase of current flow in broken down joint conditionsos there is in systems as ordarily installed, therefore, another big (llfilil upon the capacity or". the ccntrzl station and or"- the alin current ene ator is climiimtcd.

I this etem ol lies in the tact *rned in the the wires tact in orriuallyn so relied upon method of protcclici'i are moi and c micctions which must he dcr for the syslen. to ope that if any of tilt connci' ito secure ln'oli'cdown not intact the condi is inunc fol nonicd by the failure oi the '1 to operate as it 'cndcd to i'i rmully Upiill} I vcll on that inc shamiddle limb ol "once would be in power fa t r uit would 1h nccomc so low hat s mowing in such HV-lllli woulu be he n 5o d n phase 1 with the current in winding oi the rclcy l, but it migl l;l "(l still furllui so 'liEPi, :1 rotatioi relay ocrur in a direction to .i .iu ordcr lo avoid this dilliculty the-ad iusiublestops can be so phurcd that tho p wcr tractor oi the circuit containing the coil l9 and the track winding ot the relay in the adjacent section.

is never decreased to point below the power factor of the current containing the n my local winding of the relay in the adjacent Although applicant has herein shown and described a. ccppc' annulus as being placed about the coil 12 of the automatic rcuctancc device, it mustv be distinctly understood that such is not a necessary part of applicants invention and that the same would only he used under extreme conditions when, for instance. the phase of the (summit flowing to the track phase of the relay under normal conditions displaced at too great an elem lriral imglc to the phase of the electromolivc force.

Although applicant has hcrcin shown and described his invention as applied to an automatic block signal system, applicant wishes it to be understood lha t the invention is by no means limited to such a system, for the lninciplc underlying the invention is applicable in ciimucclion with track circuit sci-lions used for any purpose.

llaving explained the principle of my invention and described the construction and mode of operation of a part icular physial embodiment thereof, what l clailn as new and desire to secure by Letters Patent is:

l. in a. system oi track circuit signaling: a source of alternating currcnt: a lruckway composed in rails: insulating joints in the rails at intervals forming sections; a trans lati :g device in each section having two u'iudiu" connections from onc of the wimlin i, o the source o'l' current; courier .i'om the other winding to the lraclt ls: con; \ullhllr between the source of cur nt and the rails in cuch section; and a device inserted in said last numcd conucc lions adapted to change the phase ol current flowing lhcrcthrmigh upon a breaking down oi the insulating joints between two abutting; sci-lion and the completion of a circuit from the connections from the source 0t alternating current in one section through lhc winding 01" the translating dcvicc of thc zul iaccnl section connected to. the track rails, the change bcing such that the current will have a phase dill'crcnt from that, of the current which properly flows in the adjacent section, so that the improper flow of current will not cause the same operation of the 2. In 2 system of truck cirmit Sif a source of alterna mg current a lnsulatnw 5 composed of mils rzuls at lntervuls for translating device in each sicv tions between the translating w v T1 1 v Flu.