US1794570A - Interlocking system for railroads - Google Patents

Description

March 3, 1931;

SN. WIGHT INTERLOCKING SYSTEM FOR RAILROADS Filed Nov.

Patented Mar. 3, 1931 UNIT rails as r SEDGWICK N. WIGHT, or noonns'rEnnnW YOBK, ASSIGNOR To GENERAL RAILWAY "r 'oF I e SIGNAL COMPANY, OF ROCHESTER, NEW YORK 'IN'TERLOGKING sYsrEi/rros RAILROADS 7' Application filed November 8, 1929. Serial No. 405,625.

This invention relates to interlocking systems' and more particularly to the provision. of meansfor controlling ail-interlocking plant located at a great distance from thedispatchers oflioe economically and over a co1npara tively few line wires; p

When two railroad tracks cross each other at the same grade 1t 1s necessary to provide interlocking means to prevent a collision be 1,2 tween two trains at such crossing. In. a'c-' cordance with the usual practice-there are not only provided signals of the stop-a-nd-stay type at the approach to such a crossing, but derails are also provided, and these derails are in their active derailing position normally and are only cleared when the derails of the conflicting route are in their active position. lnaccordance with the present invention it is proposed to operatethe derails and signals of one of the conflicting tracks over separate circuits, and to indicate over these same-circults when the derails are operated, when a train passes over such derails and which or" the signals 1s 1n a proceed POSltlOIl;

Other objects, purposes and characteristic features of the invention are in part apparent from the accompanying drawings and will in part be pointed out in the description hereinaiter.

a? In describing the invention in detail reference will be made to the accompanying drawings, in which the portion in the dotted rectangle at the left indicates the apparatus located in the interlocking tower and the re maining portion indicates the apparatus at the distant railroad crossing.

. Referring to the drawings there have been shown an east and west track' EW having rails 1, and a north and south track NS hav- 49 ing rails 2, of two conflicting railway systems.

The present invention has been shownapplied to the east andwest system, which has associated therewith an east bound derail DRE and west bound derail DRW. These derails are each operated by a switchmachine mechanism of the usual construction, which has been conventionally illustrated. Train travel is directed'over the derail DRE through the medium of the stop-and-stay signal and [I train travel is directed over the west b H cordance with traffic conditions.

derail DRW by the stop-and-stay signalSW,

home relays EH and WH beingprovided forcontrolling these signals, respectively, ac-

The track section between the signals SE and SIV is in sulated from the remaining track by insulating joints 3, and is provided with the usual track circuit includinga track relay. T and a track battery 4- The derails DRE and DRW' are controlled through the medium of a control relay 2Z, whereas the signals SE and SW are controlled in accordance with 'trafiic conditions by the control relay 1Z, the operated condition of the track relay T also entering into the control of the signals SE and SW, whereas the operation of the derails DRE and DR? is dependent upon the relay 2Z and the condition of train travel as determined by an approach locking arrangement such as shown 7 1n my prior applicatiomSer. No.120,4:23, filed purpose of which will be described herein indicate occupancy of the track'circuit at the a distant interlocking plant, and the indicating lamp I indicating operation of the derails DRE and DRW. There are also pro vided in the interlocking tower IT relays IR, 23, and IX, the purpose of which will bepointed out in the operation of thesystem hereinafter. Having now pointed. out the various elements of the system, it 'is deemed expedient to take up the operation thereof to observe their coaction. A

079emtz'0nsr Let us assume that the inter.

locking operator has been informed by suitable means, not shown, that there is an east bound train approaching on the track EW, and that hewishes to clear-the signal SE to allow such train to pass over the railroad crossing. In. order to do this he will'first be required to operate the two derails DRE and DRW to their abnormal ineffective position. This will be done by moving the lever L to the right thereby closing the following circuit for the relay 2Z: beginning at the positive terminal of the battery 10, wires 11 and 12, lever L wires 13 and l l, winding of the relay 2R, line wire 15, front contact 16 of the relay 20S, wire 17, Winding of the relay 2Z, wires 18 and 19, contact 20 of the signal SS, wire 21, signal blade contact 22 of the signal SN, wires 23 and 24, common return wire C, Wires 25 and 26, back to the midpoint of battery 10. It will be noted that this circuit cannot be completed unless the signals SS and SN of the conflicting track are in their stop position. Completion of this circuit effects energization of the control relay 2Z and the indicating relay 2R.

. lV-ith the control relay 2Z energized to the right, it being assumed that current flowing from the positive terminal of the battery 10 will operate relay 2Z towardthe' right, the

following circuits for energizing the derail machines DRE and DR f are closed, this on the assumption that the approach locking relay AL is energized and that the approaching train has not yet approached within the approach locking zone preferably extending braking distance in the rear cf the signal SE :-beginning at the terminal B of a suitable battery, front contact 28 of the approach locking relay AL, wire 29, contact" 30, wire 31, polar contact 32, of the control relay 2E assuming its right-hand position, wire 33,

and then the two circuits divide through wires 84 and 35 to the two derail machines DRE and D 3V, and thence to the common return Wire C connected to the other terminal of said battery. The completion of these circuits causes operation of the derail machines and DEVI, and as soon these machines have been unlocked the following circuit for the relay 2W is broken: beginning at the terminal B, wire 36, contactB? of the derail machine DRE, Wires 38, 39 and 40, contact 41 of the derail machine DEVI, wires 4-2 and 43, inding ofthe-relay 276, 1 to the terminal C connected to the other side of said battery.

he breaking of this circuit for the relay TWP causes the contact 4'5 of this relay 2W to assume its retracted position, thereby reversing the polarity of the current applied to the relay 20S, and causing the relay-20S to assume its (lo-energized position and mo men-t thereafter again assume its energized position. This is accoinipli lied by opening of a circuit starting at the negative terminal of battery thro-ugh46, 4?, &8, 49, 14, i5, 8, 20$, 9 and 56; and closing of a circuit starting at the positive terminal of battery 5-0 understood that relay 2Z cannot be operated unless relay 20S is energized, butif relay 2Z has once been energized it may be held up through back contact 16 of relay 20S, the relay being suiiiciently slow dropping as conventionally shown to prevent it dropping during dropping of the contact 16.

De-energization of the relay 20S Opens the line circuit including the line wire 15 and effects de-energization of the relay 2R in the iiterlocliing tower IT, but such die-energization of relay 20S does not effect de-energiation of the contr l relay 22?, because this control relay 2:1 is maintained stuck up through the following stick circuit: beginning at the positive terminal of the battery 50, wire 51, contact 52, wire 53, neutral contact 54 of the relay 2. 1, wire 55, contact 16 of the relay 20S in its retracted position, Wire 1'2, winding of the relay 22 '. wires 18 and 19, contact 20 of the signal. SS, wire 21, signal blade contact 22 of the signal SN,-wires 23 and 56., back to the midpoint of the battery 50. Momentary dc-cnergization of the relay 2Rcauses the folio ring circuit to be momentarily completed for the indicating lamp 1: beginnin atthe positive terminal of the battery 10, wires 11 and 12, contact of lever L wires 57 back contact 58 of the relay v e indicatin, lamp 1, wires 62,63, 64, and baclr to the midpoint of the battery 10. This momentary illumination of the indicating lamp I informs the operator that the derails have been started on their cycle of operation from their active to their inactive position or ice versa, and when these deraiis have completed this cycle of operation the same energizing circuit except that contacts 37 and 84 assume their dotted position for the relay 216 1 i's'again completed, the contact 45 of this relay is operated to its attracted position, thereby again reversing the aolarity of current applied to the relay 20 and again offectingmomentary illumination of the inclicating lamp 1, for reasons just explained,

When the operator has received this second flash of the indicating lamp I he will return his lover L to the neutral position and will operate the lever L to the right-hand po sition in order to clear the east bound signal SE. This movement of the lever L effects closure of'the following circuit :,beginning at the positive terminal of the battery 10, * ires 11 and 66, contact of thelover L wire 67, winding of the relay 1R, line wire 68, front contact 69 of the track relay T, wire 70, winding of the relay iZ, wires 71 and 19, contact 20 of the signal SS, wire 21, contact 22 of the signal SN, wires 23, 24, C, 25 and 26,

aclr to the midpoint of battery 10. It will be noted that the circuit just traced cannot be closed unless the track circuit containing the'traclr relay T is unoccupied. The completion of the circuit just traced energizes the control relay lZ towa "d the right,the re lay lZ bemg connected to so operateyand with this relay lZ energized toward the right the east bound signalSE is permitted to clear, providing traffic conditions in advance of the signal SE, are proper as manifested by the home relay EH and providing that both the derail DRE and the derail DE /V have been moved to their abnormal closed track posit-ion. This circuit for the signal SE may be traced as follows:beginning at thetermi-' nal B of aisuitable battery, neutral contact 72 of the relay 1Z,wire 73, polar contact 74;

of therelay lZ toward the right, Wire 75,

neutral contact 76 of the home relay EH,

wire 77,.polar contact'78 of the home relay" EH toward the ri 'ht (assuming clear traffic conditions ahead) clear wire v7 9, mechanism of the signal SE, (for itsvcolored signal lamp if a light signal is used) wires 80 and8l, contact v82 of the derail DRE, wire 88, contact84: of'the derail DEW, wire 85 to the other terminal C of said battery. It is thus noted that the signal SEcannot clear unless the operator has operated the control relay lZ toward the right, traffic conditions as manifested by. the home. relay EH are clear, and unless the deraiL-machines DRE and DRlV are in their closed track position. 7 The completion of the circuit forenergizing the control relay lZ also effectsenergization of the indicating relay 1R. Also, with thelever L in its right hand position the relay 1X is energized to'the right, for obvious reasons. VViththe relay 1R energized and the relay 1X energized toward theright, the following circuit for the miniature signal so is closed: beginning at thepositive terminal of the battery 10, wires 11 and 66, contact ofthe lever L wires 87 and .88, front contact 89 of the relay 1R, wire 90, contact Slof the relay 1X toward the right, wire 92, lamp of the miniamidpoint ofbattery 10. r

If now the train in question accepts the ture signal .86, wires 93 and 65, back to the signal SE and proceeds into the tracksectionv between the signal SE and SW, the track relay ,T is de-energized, thereby opening its contact 69 and effecting de-energization of the control relay lZ and the indicating relay 13. With the relay 1R assuming its retracted position and the lever L in its right-hand position the following circuit for the track occupancy indicating lamp 256 is closed: beginning at the positive terminal of the bat-, tery 10, Wires 11 and 66, contact of the lever L wires 8'? and 88, contact 89 of the relay 1B in its retracted position, wire 95, signal lamp te, wires 96, 64 and 65, back to the midpoint of battery 10. Also, de-energization of the indicating relay 1R will effect extinguishment of the signal lamp 86, so that the op erator is informed that the train is passing through the' track section between thesignals SE andSlV.

By reason of the fact that the approach locking relay AL is controlled by an ap proachlockmg'circuit such as disclosed in my prior application, to which reference has been made, the derails DRE and DRl V cannot be operated if there is a train approaching from either. direction, unless-this train has accepted the distant signal (not shown) at caution or stop, all as, explained in "said prior application. From this it will appear that the derail machines DRE and DEW cannot be operated in the faceof an approaching train. Further, it will be noted that the signalsfSE and SW cannot be cleared unless both derails are in their abnormal continuoustrack position. 3

Applicant has thus provided a system requiring onlytwo line wires and acommonreturn Wire for safely. operating the derails and signals at a railroad crossing, the cir-;

cuit arrangement being such that the operator is informed as to the operation of the derails, the position of signals and the occupancy of the track section in which such derailsarelocated thiss stem havin all.

of its interlocking features located; at the distant interlocking plant, so that any line troublebetween the distant interlocking plant and the interlocking tower cannot possibly cause false operationof the derails ortheclearing of signals, unless it is safe to so" operate them. In practice the track NSof the other system will be protected by suitable interlocked signals which are preferably controlled in the same way.

Having thus shown and described one rath-' er specific embodiment of the present invention it is desired to be understood that the particular circuit arrangement illustrated has been selected to facilitate description of the invention, and its operatingcharacteristics and underlying'principles ofoperatlon, and has not been selected with the lntent of showing the scope of the. invention or the exact construction preferably employed in practicing the same, and that various changes, mod1ficat1ons,'and additions may be made to adapt the invention to the part cular railway system to which it is to be applied, all without to said tower, a track circuit for manifesting the passage of a train over said derails 1ncludlng a track relay, a front contact of said track relay included in the circuit for said control relay, indicating means at said tower included in the circuit of said control relay, and a lever for controlling the flow of current in said control relay, whereby said derails can be operated and the occupancy of said track circuit can be indicated over the same line circuit. i

2. In a remotely controlled interlocking system, the combination with two railroads crossing each other, of derails on one of said roads to prevent a train on said road crossing the other road, a controlrelay for controlling said derails effective only if signals governing traffic over the other road are at'stop, a distant interlocking tower, a circuit including said control relay leading to said tower, a track circuit for manifesting the passage of a train over said derails including 'a track relay, a front contact of said track relay included in the circuit for said control relay, indicating means at said tower included in the circuit of said control relay, a lever for controllingthe flow of current in said control relay, whereby said derails can be operatedand the occupancy of said track circuit can be indicated over the same line circuit, signals associated with saidderails, and other means for controlling said signals from said distant tower. V

3. In a remotely controlled interlocking system, the combination with two railroad systems crossing each other, of wayside signals on one system for blocking the movement of trains over said crossing, derails associated with said signals for enforcing obedi ence of'trains to said signals, a derail-relay controlled from a distant tower for controlling said derails, approach locking means for preventing operation of said derails by said derail relay unless there is no train approaching in an approach zone which did not pass an adverse signal, a signal control relaycontrolled from said distant towerfor controlling said signals, and means for preventing control of said signals by said signal relay unless traflic conditions in advance of'sucli signals are favorable 4. In a remotely controlled interlocking system, the combination with two railroad systems crossing each other, of wayside sig- I; nals on one system for blocking the movement of trains over said crossing, derails assoclated with said signals for enforcing obedience of trains to said signals, a derail relay controlled from a distant tower for controlling said derails by said derail relay unless there is no train approaching in an approach zone which 'did not pass an adverse signal, a signal control relay controlled from said distant tower for controlling said signals,

means for preventing control of said signals by said signal relay unless trafiic conditions 1n advance of suchfs gna'ls are favorable,

trolling said derails, approach locking means for preventin operation of said derails by said derail relay unless there is'no train approaching in an approach zone which did not pass an'adverse signal, a signal control relay controlled from said distant tower for controlling s'aid-signals, means for preventing control of said signals by saidsignal relay unless trafiic conditions in advance of such signals are favorable and means for indicating at said'tower the passage of a train over said derails.

6. In a remotely controlled interlocking system, the combination with two railroad systems crossing. each other, of wayside signals on one system for blocking the movement of trains over said crossing, derails associated with said signals for enforcing obedience of trains to said signals, a derail relay controlled from'a distant tower for controlling said derails-by said derail relay unless there is no train approaching in an approach zone which did not pass an adverse signal, a signal control relay controlled from said distant tower for controlling said signals, means for preventing control of said signals by said signal relay unless traflic conditions in ad Vance of such signals are favorable, other signals on said other railroad system for governing the movement of trains over said crossing, means for preventing operation of said derailsunless said other signals are at stop, and means for indicating at said tower the passage of a train over said derails.

7. In a remotely controlled interlocking system, the combination with two railroads crossing each other, of derails on one of said roads for preventing a train on said road crossing the other road, signals for governing the movement of trains over said derails, power operated means for operating said derails, a control relay for controlling said power operated meansand controlled from a central oflice, meansfor indicating at said office the response of said power operated means to said control relay, other signals on the other of said roads for governing the crossing of trains over said one road, means for preventing operation of said power operated means if one of said other signals indiv cates proceed, and means for clearing said first mentionedsignals effective only it said derails assume their closed track position.

8. In a remotely controlled interlocking system, the combinationwith two railroads crossing each other, of derails on one of said roads for preventing a train on said road crossingthe other road, signals for governing the movement of trains over said derails, power operated means for operating said de rails, a control relay for controlling said power operated means and controlled from a central otfice, means for-indicating at said oliice the response of said power operated means to said control relay, other signals on the other of said roads for governing the crossing of trains over said one road, means for preventing operation of said power operated means if one of said other signals'in- 'dicates proceed, and means for clearing said first mentioned signals en' ective only it said derails assumetheir closed track position and there is no train approaching at speed on said one road.

9. In a remotely controlled interlockingsystem, the comblnation with two ItllI'OEtClS crosslng each other, of derails on one of said roads for preventing a train on said road crossing the other road, signals for governing the movement of trains over said derails, power operated means for operating said derails, a control relay for controlling said power operated means and controlled from a central oflic'e, means for indicating at said office the response of said power operated means to said control relay, other signals on the other of said roads for governing the crossing of trains over said one road, means for preventing operation of said power operated means if one of said other signals indi' V cates proceed, means forclearing said first mentioned signals effective only it said derails assume their closed track position, and means for indicating at said central oflice the passage of a train over said derails.

10. Ina remotely controlled interlocking system, the combination with two railroads crossing each other, of derails on one of said roads for preventing a train on said road crossing the other road, signals for governing the movement of trains over said derails, power operated means for operating said derails, a control relay for controlling said power operated means and controlled from a central oliice, means for indicating at said office the response of said power operated means to said control relay, other signals on the other of said roads for governing the crossing of trains over said one road, means for preventing operation of said power operated means if one of said other signals indicates proceed, means for clearing said first mentioned signals efiective only if said derails assume their closed track position and there is no train approaching at speed on said one road and means for indicating at said central office the passage of a train over said derails.

11. a remotely controlled interlocking system the combination with two railroad systems crossing each other, of wayside signals on one system for blocking the movement of trains over said crossing, derails associated with said signals for enforcing obedienceof trains to said signals, a derail relay controlled from a distant tower for controlling said derails, approach locking means snnew on N. wrenr.

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