US1113511A - System of automatic block-signaling for electric railways. - Google Patents

Description

FLTOWNSEND, DEGD.- I J. J. TOWNSEND, ADMINISTRATOR.

SYSTEM OF AUTOMATIC BLOCK SIGNALING FOR BLEGTRIG RAILWAYS.

APPLICATION FILED MAY 31, 1906.

Patented Ot.13,1914.

2 SHEET$-SHEBT l.

I J. J. TOWNSEND, ADlQiNI'STBATOB. I

SYSTEM OF AUTOMATIC M0011 SIGNALING FOR ELEGTRIG RAILWAYS.

' APPLIOATIOR FILED, MAY 31, 1906.

' 2 SHEETS-B1133"?- WITNESSES: INVENTO'R A ORNEY x er i r" "in i are in linen rournsnnn, or new resign. r2; JOHN J. rowusnnn, nmnmrsrnnron cs sew menses. rcwnsnnn, @ECMLEED, essisuon we answer. neinw es srsnsn screensr, .e. comment-econ ee NEW some.

sieeificenen of Letters slatcnt,

were son ELEGTEIC summers.

I Pstensecl @cl 313,1314;

fzpplicscion filed may 31, 15506, Serial filo. $19A-23.

To all whom it may concern:

Be ii; known that I, FITZHUGH Towrzsnnn, a citizen of lghe United States, residing at- New York city, county and State of New York, hare invented a System of Automatic Block-Signalin for Electric- Rnih Ways, of which the following is n specifiers tion.

l have invented an improved system of em.- lLOHlatlG block signaling, applicable to electrio rsilwn s in Which'nn alternaeing current is employed to operate the cars. In my invention the control 0 5 the signaling mechanisms is uccrmiplislied by segregated portioiiof the propulsion current, acting either in conjunction with the propulsion currenfzQor with another rated portion thereof. I am able, therefore, to use a single feeder from the generazor, and both of the rails as returns for all current to the generator, thus ino'l'ermlly reducing the cost of the signaling system einployed. l urtherniore, by theerrengenient to he described, a break in one rail will re: duce the action of the signaling controlling mechanisms to zero, even where several tracks are tied together electrically. The operation of my system is independent of slight changes in the relative conductivity of the trnilic rails; and leakage currents, whether direct or idle/routing, Willnot u ll'ecs the signal mechanisms.

In the practice of 111; invention, she. truflic rails are divided into block sections, and the propulsion current flows from. bloc section to block section along both rails Without being materially impeded; the propulsion current flowing in the same direction in both rails, and returning thus to the power generator. in each block; section a segregated portion of the propulsion current, or n current derived from the some source as the propulsion current, or from a separate generator in synchronisni with the propulsion generator, is displaced in phase from the propulsion current- ,in the trnliic rails and l-runsn'iil'ted in each hlocl: section do n one rail and up the other, and limited in its llow to the block section. There is, therefore. a dii'lerem'eof pull! and plnisehetuecn the current employed to operate the cars and that ciuployml to conlrol the signals, which difference is utilized in carrying out my invention.

means of s The accompanying diagrams will serve to illustrate my invention.

Figure l illustrates'n single-phase, clitornatiiig currcnt'rnilmiy in which automatic block sigiialsare co troll'e from-she r ck circuits in accordance with my invention; Fig. is a dis 7 ofcoils suitable for the relay bond oh Fig. 1; Fig, 3 illustrates a modification of my invention in which the: tne lic rgrils Meltonl section by "a nected stench end of one clock reuclnnce bond, fihe ends of, ndjacfens sections heir conucctedny n csenductor which includes a reactance, Figf'l illuslrates an arrangement similar so that shou hin 3, and boring :1,- inodifiecl form or renctoncc bond at ench end of? the block seciions constructed in the manner hereinafter (lescrihecl.

- In Fig. 1, l is the propulsion current generator supplying a, single phase alternni'ing cnrrens e the outgoing; trolley Wire or feeder conductor 2. Said propulsion current operates any motor vehicle 'as 5, which may he on the system. and returns to the power generator through traffic rails el. and 5, being conducted iron one block section to the next by means of the coils of the relay bonds 6 and the resctance bonds 7. X, if, E, are block sections. The relay looncl comprises two stator or field coils 8 and 9; the coil 9 should orererahlv have half the e g L D n znumber 01 turns 0:. Lllfi coil c. @118 end or the c 9 is connected to the middle point of izhe coil 8, and the other end is connected to the middle point of reactsnce bond 7, through conductor 10. 11 is tlie'rnovshle member of the relay device and consists of s rotor Wound with a short circnited winding eisher definite squirrel cage, in the ordinary manner of induction motors and designed to give maximum "eorque at stand still. a transformer, the 'niinary 13 of which is energized from the outgoing feeder 2, through conductor 14. The secondary 153 is connected across the trnilic rails d and 5 through conductor 16: and means of phase control 17 and 18. These are shown consisting of an adjustable resistance 7 and an adjustable reactance 1%, but of course any other convenient 111621118 or phase control may be employed. Th phase controlling means is employed to nmlze the oi": the signaling current suppliedhy lhe secondary e'rn n showing n arrangement 15 to the trafiic rails 4c and 5 difier (about ninety degrees) from that of the propulsion current. The phase adjustment may be fun ther. assisted, by giving a suitable value to the power factor of the reactance bond 7;

said reactance bond may, of course, be made either of the closed or open magnetic cuit type and may if desired, be designed to attain saturation at any suitable value of unbalanced propulsion current M. M. F. 19 is a transformer, the primary winding 20 of which is in parallel with that of trans former 12. The secondary Winding 21 of transforn'icr 19 is connected in series with the contact 22 and the solenoid coil 23 of the signal 24. Said secondary .21 also supplies a current of particular phase to conductor Sui-d current flows through coil-9, and completes its circuit through the means of phase control 26 which is here shownas an ohmic resistance. The object of this means of phase control is to cause the current l lo-5ving through it to be substantially the same in phase as the propulsion current. The lat; tcr phase is fixed by the power factor of the railway system, and it will be obvious that the means of phase control 26 should preferably be adjusted to have the right combina tion of resistance and reactance so as to coincide in phase with that of the propulsion current in the trallic rails. In the event of there being no propulsion current, thercfore, the auxiliary current thus supplied by transformer 19 through conductor 25, will take the place of the propulsion current and act in conjunction with the signaling current, in coil-8 of the relay, to hold the relay contact 92 closed by the exertion of a turning moment of the movable member 11.

In the operation of this form of my device, the prdpulsion current flows from one block section to the next into both ends of the coil 8 of the relay bond 6 and out at the middle point of said coi through coil 9, and thence to-the adjacent reactancc bond 7, thus passing from one block section to the next. The action of the propulsion current in the relay bond is to produce a flux in the coil 9, and if the propulsion current carried by both trailic rails is the same in quantity, no flux would be produced by said propulsion current in the coil 8. Should, however, there be unbalancing between the currents carried by the two trallic rails, some flux may be produced. in the coil 8. 3 Such flux,

however, will be in phase with the flux be fore mentioned produced in thecoil 9. It is plain, therefore, that acting by itself the propulsion current can never produce a rotary field, since in order to produce this result, it would be necessary to have these fluxes displaced in phase in coils 8 and 9.-

Transfornicr 1.2 at the energy end of the block sect on sends a current through the rails i and 5, which is displaced in phase by means of the devices 17, 18, so as to differ (approximately ninet-y'degrees) in phase from the propulsion current, the phase of the latter being, of course, substantially constant on account of the fact that it is determined by the power-factor of the system. This current, which I will call the signaling current, passes down rail 4 through coil 8 and up rail 5, and it does not How through coil 9. This signaling current produces a flux in coil 8, differing in phase from the flux in coil 9, due to the propulsion current in the latter coil; consequently, the presence of the signaling current in coil 8 acting in conjunction with the propulsion current in coil. 9, will result in a rotary field, which normally, in the absence of a car on the member 11 to close the contact 22, thereby allowing the solenoid 23 to be energized so as to hold the signal 24 in a clear position, as shown in block section Y. Then a car enters a block section, the wheels and axles short-circuit the traiiic rails 4 and 5, thus shunting the signaling current away from the coil *8. This removes the flux of displaced phase from the coil 8 and destroys the rotary field. The result is that the turning moment of the movable member 11 is reduced to zero and the contact 22 is opened, thus denergizing the coil 23 and sending the signal 24 to the danger position, as in block section Z. It is assumed that the direction of motion of the car is away from the generator. It may, therefore, be that under certain conditions, there rails ahead of the car 3, consequently, a signal might stand wrongly at Danger 1n the current in the coil 9 of a relay bond. In order to provide against this contingency, transformer 19 normally sends. a current similar to the propulsion current through the coil 9. It will be plain from this description, that any current whatever, of any block section to the next, and consequently traverses both the coils 8 and 9 of a relay bond, cannot alone produce a rotary field, since the fluxes in both coils due to such currentmust be in phase owing to the series connection.

. Fig. 1, shows a single track. in the event of there being more than one track, the corresponding conductors 10 of the various tracks at each block section would be counected together by cross bonds so as to facilitate the return of the propulsion current. If return feeders are employed, they should .be connected to the return system at conductors 10. This will be evident to vmy signaling engineer. It will be seen that any ljfront of the car, due toa lack of propulsion.

frequency or phase which flows from one brealwin eitncr rail 4 or rail 5, will reducethe turning momentof tlie movable member;

block section, causes the rotor or movablewill be no propulsion current in the traffic I in case of a broken rail. would flow through half 0% winding 8, through Winding 9 and from conductor 10 through the cross bonding to the initial end of the block section, completing its circuit through {one-half of the reactance bond 7 at the initial end of the clock. It will be seen that under such circumstances. the fluxes in the coils 8 and 9' would be of the same phase on account or the series connection, so that there would be no rotary field and no turning moment of the movable member 11.

In Fig. 2, the coils 8 and 9.,are shown disposed in slots along. the periphery of a stator core 27, in the ordinary manner of an induction motor and are displaced by ninety degrees. Conductors 28 and 29 are designed to be connected across the two trafiic rails of a block section, as is shown in the case of the terminal leads of coil 8 in Fig. 1. Conductor 30 is to be connected to the middle point of the reactance bond 7, Fig. 1, of an adjacent block section. One terminal 31 of coil 9 is connected to the middle point of coil 8, the coil 9 is shown as having half the number of turns of coil 8. The movable member 11 shown placed concentrically Within the surrounding stator 27. It will be understood or course that in actual practice, it will be preferable to dispose the end connections of the coils 8 and 9, around the circumference of the stator core 27, as is usual in the construction of induction motors. Fig. 2, is entirely diagrarnmatiqand the contact arm, shaft bearing and. supporting base, which would be used on an actual relay, are omitted.

In Fig. 3, a reactance bond 7, tapped at its middle point, is shown connected across the rails at each end of a block section. The middle points of adjacent reactance bonds are connected together through an additional reactancc bond 31, and which provides for transmitting the propulsion current from one block section to the next. It will be understood that the reluctance of the magnetic circuit of the reactancc bonds 7 and 31 may, of course, be designed to suit conditions so tl at saturation will occur with any desired value of the propulsion current traversing them. The power factor of said rencliancc bonds should preferably be the same. The relay device -(3' comprises the stator coils S' and 9, together with a movable member 11. The coil 8 is connected to the terminals of the reactance bond 7 and the coil. 9' isconnected across the terminals of the reactauce bond 31. as in Fig. 1, that the propulsion. current can It will be seen,

never produce a rotary held, since the currents in coils 8 and 9 must necessarily be in phase with each other and the flux produced by them, must consequently be in phase. in this arrangement of my device (Fig. 3) signaling current as in Fig. 1, is

transmitted "from a transformer 12 to the rails 4 and 5. This signaling current, displaced in phase by the eviccs l? and 18, flows partly through the reactance bond 7 at the relay end, and partly through the coil 8"; this current will produce a magnetic flux in the coil 8 dififering in phase from. that in coil 9. The result will be a turning movement of the movable memher 11, in the absence of a. car in the block section, the contact 22 being closed and the signal 94 held in the clear position by means of the current supplied from the battery lVhen a car enters a block section, the signaling current will be shunted away from the coil 8', destroyin the rotary field of the relay (3, so thatthe contact 22 will 0 ion and the signal go to Danger, as shown in block section Z. It is assumed that the direction of traffic in this figure (3) is toward the generator. Thepropulsion current, therefore, after leaving the Wheels of the car 3 must necessaril flow alon the tral'lic rails 4 and ahead of the car and in the direction of its motion. it may be presumed. therefore. that there will. be enough propulsion current in the block sections ahead of the car lo act in conjunction with the signalingcurrent of transformer 12, to hold the sigi'ials of the unoccaipied block ahead in the ole r position. On this account, therefore, transformer 19, which supplies the auxiliary current, as described in Fig. l, is omitted as unnecessary. lit may, of course, be supplied, if desired. in a rail- Way system employing a number of cars, there will be a return power current flowing through the rails at all times.

In 4:, the trai'iic rails are connected at each end of each block section by one coil 33 of a reactancc bond 3%. llound in inductire relation with, the coil 33 is a coil 35. The coil is connected between the rail 5 and one terminal of the bond 31, which joins one block section to thenext. It will be seen, therefore, that the coil carries the entire propulsion current, while the coil 33 only carricshhe n'opulsion current of rail 4. Coil 35 is Wound Willi half the number of turns of coil 33 and in an opposite direction, 0 that the magneto motive forces of IN; 'tu'o COllcZ'Wlll be equal and opposite, provided the propulsion current equally dividcd between the rails land 5. The power factor of the bonds 3i and for the power current should be approximately the same.

:Ellk, operation of this l'orm of my invent on, is similar to that described in con ncctlon withv F l and Any current flowing from block section tolhlock sectioncannot by itself produce a rotary field and actuate the relay 6', but a signaling current of displaced phase supplied by transformer 12 and flowing in coil 8, will, in conjunction with the current carried by coil 9', produce a turning Inomentof the movehle member 11, normally sending the signal 24: to the clear position, as in block section Y. Similarly, as, in block section Z, the presence of a car will shunt away the signaling current from the coil 8, destroy the rotary held and sending the signal 2e to the danger position.

In describing my invention, I have shown several arrangements of circuits, bonds, etc. It will be obvious to electricians that instead of using a single generator for the propulsion and signaling currents, I may use two generators transmitting currents corresponding in frequency. Further, that instead of using a two-phase relay bond, 1 may use a three-phase bond. Further, I may change the general} arrangement of the circuits without in any wise departing from the general rinciple of my invention. What I wish to ave understood is. that I consider myself t he first to have described a system wherein the propulsion current 00* acts ,with ano her current to produce a movement of the relays to indicate a clear signal and to indicate the continuity of the rails of the system; and further, the

employment in a signaling system of a sig-' nal controllin device having its stator member energize when no car ison a block by the conjoint action of the propulsion and signaling currents. Further, the employ.- ment in such a system of reactance bonds having coils thereon so arranged that such bonds will inter-pose reactance to the alternating signaling current, but no reactance to the alternating power current; and further, the employment of means for insuring the operation of the signal controlling device in the absence of the propulsion current, etc.

' Having thus described my invention, I claimr 1. A signaling system for electric railways, comprising a trackway divided into block sections, react-ance bonds, one positioned at each end of each section, each bond comprising a core and two coils thereon, one of said coils connected across the trackway and the other of said coils connected to one rail at one end and at its opposite end to the corresponding end of a similar coil of the adjacent bond.

2. A signaling system for electric railways, comprising a source of energy, a trackway divided into block sections, reactance bonds between the block sections, means for exciting a difi'erence of potential between the rails of the block sections, a signal controlling device in each block section normally energized by the current returning along the rails and the current due to the difference of potential between the rails, means for changing the phase relation of said currents, a local circuit anda,-

signal under the control of each signal controlling device.

3. A signaling system for electric railways comprising a source of energy, a track way divided into block sections, reactance bonds, one connected across the rails at each end of each block section; a connection be tween adjacent reactance bonds includin a reactance coil; means for exciting a di erence of potential betw en the rails of the block sections, a signal controlling device in each block section including two coils, one of said coils connected across the rails, the other connected inshunt to said reactance coil, a local circuit and a signal under the control ofveach signal controlling device.

In testimony whereof, I afiix my signature, in the presence of two witnesses.

FrrzHUon'TowusENnf VVi't-nesses FRANK Gonnon, Fnnnnmcn A. BLonNr.

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