US521711A - Supply system for electric railways - Google Patents

Supply system for electric railways Download PDF

Info

Publication number
US521711A
US521711A US521711DA US521711A US 521711 A US521711 A US 521711A US 521711D A US521711D A US 521711DA US 521711 A US521711 A US 521711A
Authority
US
United States
Prior art keywords
switch
break
line
magnet
conductor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Publication date
Application granted granted Critical
Publication of US521711A publication Critical patent/US521711A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B60VEHICLES IN GENERAL
    • B60MPOWER SUPPLY LINES, AND DEVICES ALONG RAILS, FOR ELECTRICALLY- PROPELLED VEHICLES
    • B60M1/00Power supply lines for contact with collector on vehicle
    • B60M1/02Details
    • B60M1/08Arrangements for energising and de-energising power line sections using mechanical actuation by the passing vehicle

Definitions

  • This invention relates more specifically to that class of electric railway, in which the motor circuit during the travel of the car is maintained in multiple connection between a sectional working conductor and a return conductor (or the ground) and wherein the sections of said working conductor are auto-y matically connected and disconnected from the power line by the operation of electric switches operated by the travel of the car.
  • My invention primarily consists in the peculiar construction and arrangement of the device whereby my systemv is equally well adapted to single or double track roads, and further in the novel construction and arrangement of the switching devices whereby a single magnet for each section of the working conductor controls the operation of the switch- A ing devices in a simple and efficient manner.
  • My invention also includes an arrangement of sectional return ⁇ conductor which may be used in connection with my system all as more fully hereinafter described and lshown in theaccompanying drawings, in which- Figure 1 is a diagram plan of two sections of railway track equipped with my system,
  • Fig. 2 is al diagrammatic'elevation of a motor cai showing the traveling contact on the car for operating ⁇ the switching devices.
  • Fig. 3 is a diagram showing a modi tication of my system specifically referred to.
  • Fig. 4 is an enlarged detail 4drawing vof the switch magnet showing the dierent breaks controlledby said magnet in the position in which they are held normally
  • Fig. 5 is t t a cross section of the track.
  • a A represent the rails of thel track; B the generator which furnishes the poweryO the positive lead or so-called power line and O the negative lead which in the drawings is shown connected to the rail A whereby the latter may Serve asthe kreturn conductor.
  • ductor 'it is composed of like sections insul lated from each other and preferably laid in the plane of the rails with the upper surface exposed.
  • a simple way in which this may be accomplished would be to use fiat bars for the sections of the conductors and lay them in an open conduit G filled with insulating material Gr as shown in Fig. 5.
  • the sections of the working kconductor are connected tothe power line by feeders I, one feeder for each section and these feeders have normally open breaks .I automatically controlled by electric switches K which are operated by the travel of the car.
  • the construction of these switches is as follows: L (Fig-4) is the switch magnetand M is its movable armature pivotally secured at a and normally withdrawn from the magnet by a spring b.
  • This armature carries the movable contact c which is adapted to contactwith the springs d d when the mag- .when the magnet is energized and these two contacts form a normally open break N in the circuit of the switch magnet.
  • the armature controls two other breaks O and P, the break O is normally open and is formed by the contact springg (which is moved by the insulating stud h on the armature) and the fixed contact/L'.
  • the other break P is ⁇ normally closed
  • the switches are connected lin a manner/to form two systems, one system operates as will be afterward more fully explained in the travel of the car from left to right to connectevery other section of the working conductor with the power line and the other system op- IOO crates in the same manner with the intermediate section when the car travels from right to left.
  • H to H5 indicate the sections of the working conductor which are operated by one system of switches when the l car travels toward the right and HI to I-IV indicate the alternate sections which are operated by the other system of switches when the car travels toward the left.
  • the magnet L of the switch K2i has oneterminal of its coil connected th rough t Athe wire Z withthe fixed contact of thebreaki and AJthe other terminal is connected by way t ofthe wire m to one contact of the break P Aof Jthe nekt succeeding 'like switch K2, and ,t thence bl wire n from the other contact of f said brea to the lead E.
  • the break O of the switch K2 has its spring contact connected l by wires o to -thelfixed contact'of the breakN ⁇ of Athe next succeeding like switch K3 and the nfixed contactof the break O isconnected by;J wire Lp to the yfixed contact of the break lfl ⁇ he ⁇ other switches of the systemto whichthe Q switch '1K'2 belongs are connected in like man-1 ner from the #first -to the last switch, with this dierence'that in ythe last switch (which is; represented in the drawings by the switch Kif shown fin dotted lines) the break O may be omitted as its connections cannot be coin-l' pleted; also the connection 'm of its magnet 1, coil is made directly with thelead E and thatt part of the 'feeder I connecting-the armature with the .power line is preferably omitted.
  • the break P may be omit, ted'as its contacts remain unconnected, ⁇ but in addition the fixed contact of its break is electricallyconnected through the wire q with 'the lead E of the switch battery and a normally open manual switch or push button Q iswplaced in this connection.
  • the car in ⁇ order to ⁇ operate these switches in its travel from left'to ⁇ right is provided with two conntacts or brushes R R which are fixed to the, ⁇ ca rinsuch relation that one ofthe two brushes l will alwayslbe in contact with one of the sec- ⁇ tional ⁇ conductors which the switch systern controls.
  • the magnet L of switch K is now energized by the battery current and attracts itsarmature, this closes the break N and thereby closes the switch circuit of magnet K', also by wayof the feeder I from the power line C (which also represents the lead E) to the armature and thence through break N where it joins the other circuit.
  • the actuating circuit of,'the switch K' is thus closed through two branches -and therefore the magnetL remains energized after the operator withdraws his finger from the push button.
  • The'armature of switch K remaining closes the break .I which connects the ⁇ conductor section I-I through the feeder I with the power line and the ⁇ car isthus enabled to proceed on its Way.
  • the car is enabled to travel along the track from left to right by the successive operation of the system of switches just described.
  • the armature is not connected with the power line and therefore the section H5 is lnot rendered active, but it may be connected and this last feeder may then be disconnected by amechanically or manually operated break, if desred.
  • the other switch system operates in connection with the conductor sections HI HH, &c., and. the switches of this system are constructed and arranged to operate precisely in the manneras ythe switches of the other system except that, being connected in the reverse order, they operate in the .travel of the car from right tov left.
  • the two systems of switches operateentirely independent of each other and thus.
  • my invention is applicable to either single or double track roads without the slightest change.
  • a double track road of course one track would be equipped with the conductor sections and switches adapted to operate with the car going in one direction and the other track would be equipped with the conductor section and switches operating the car in the opposite direction.
  • the wires may allbe carried under-ground and a single vconduit may accommodate them all, and the switches instead of being distributed along the line maybe arranged in any desired. accessible position.
  • vOne modification I will, however, mention in particular and this is shown in Fig. 3, in which K represents aswitch of theconstruction already described, and the modification consists in providing each switch with a second armature MI which acts in connection with the opposite pole of the magnet.A This armature controls a normally open break J', the fixed contact of which is connected to a sectional return conductor S, and the armaand thus the rail A is not needed to form the return conductor, which' obviously would increase the factor of safety in my system.
  • break J will be closed and opened simultaneously with the t (by providing the car with suitable brushes) l break .I and thus when one section of the coni ductorH is connected to the power line, the corresponding section of the sectional return conductor S is simultaneously connected to the return conductor T to the dynamo.
  • WhatI claim as my invention is- 3 1.
  • a continuous power line, of a Working conductor composed of sections normally disconnected from said powerline,aswitch line and a return switch line extending along the working conductor from a stationary source of electricity, an electro-magnet for each section of the working conductor, the armature of which is adapted to connect the section with the power-line and with the switch line, two energizing circuits for each magnet one connecting the section of the working conductor with thereturn switchA line through a normallyopen vand a normally closed break controlled by the next, adjacent magnets respectively, and. the other connecting the two switch lines through the said normally closed break of the other circuit and a normallyopen break controlled by the magnetY itself, and a contact on the ear adapted to connect two adjacent sections of the working conductor, substantially as described.
  • ing conductor composed'of sections normally disconnected from said power-line, a contact on the car adapted to connect two adjacent sections in the travel of the car, a switch and ⁇ a return switch line extending along the working conductor froma stationary source of electricity, an electro-magnet for each section of the working conductor, the armature of which is adapted to connect the section with the power line and with the switch line,

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Vehicles With Linear Motors And Vehicles That Are Magnetically Levitated (AREA)

Description

v(NoModlel.) 2 Sheets-Sheet 1f T. HARRIS.
SUPPLY SYSTEM POB. ELECTRIC RAILWAYS. No. 521,711. Patented June 19, 1894.
Il V
W @VM/ ha mmcNAL maman-ann commun wmwewu. n. c.
(No Model.) 2 Sheets-Sheet 2.
T. HARRIS.
SUPPLY SYSTEM POR ELECT-RIG RAILWAYS. No. 521,711;v Patented June 19,` 1894. Y
W/ms ses 'me Am-:NAL urnoulurums courmv.
wAsummTon. D. c.
l. Unirse SrA'rssPariN'r Errea,
THOMAS HARRIS', OF DETROIT, MICHIGAN.
SUPPLY SYSTEM FOR ELECTRIC RAILWAYVS.
t v SPECIFICATION forming part of Letters Patent No. 521,711, dated .Tune 19, 1894.
Appncaen nea Aprn 2a. 189s. serial no. 472,163.' (No model.)
To all whone it may concern:
Be it known that I, THOMAS HARRIS, a citi- -zen of the United States, residing at Detroit,
in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Electric Railways, of which the following is a specification, reference being had therein to the accompanying drawings.
This invention relates more specifically to that class of electric railway, in which the motor circuit during the travel of the car is maintained in multiple connection between a sectional working conductor and a return conductor (or the ground) and wherein the sections of said working conductor are auto-y matically connected and disconnected from the power line by the operation of electric switches operated by the travel of the car. i My invention primarily consists in the peculiar construction and arrangement of the device whereby my systemv is equally well adapted to single or double track roads, and further in the novel construction and arrangement of the switching devices whereby a single magnet for each section of the working conductor controls the operation of the switch- A ing devices in a simple and efficient manner.
My invention also includes an arrangement of sectional return`conductor which may be used in connection with my system all as more fully hereinafter described and lshown in theaccompanying drawings, in which- Figure 1 is a diagram plan of two sections of railway track equipped with my system,
lthe two sections shown being supposed to form together a complete line of single track railway. Fig. 2 is al diagrammatic'elevation of a motor cai showing the traveling contact on the car for operating `the switching devices. Fig. 3 is a diagram showing a modi tication of my system specifically referred to.
` Fig. 4 is an enlarged detail 4drawing vof the switch magnet showing the dierent breaks controlledby said magnet in the position in which they are held normally, and Fig. 5 is t t a cross section of the track.
A A represent the rails of thel track; B the generator which furnishes the poweryO the positive lead or so-called power line and O the negative lead which in the drawings is shown connected to the rail A whereby the latter may Serve asthe kreturn conductor.
ductor; 'it is composed of like sections insul lated from each other and preferably laid in the plane of the rails with the upper surface exposed. A simple way in which this may be accomplished would be to use fiat bars for the sections of the conductors and lay them in an open conduit G filled with insulating material Gr as shown in Fig. 5. The sections of the working kconductor are connected tothe power line by feeders I, one feeder for each section and these feeders have normally open breaks .I automatically controlled by electric switches K which are operated by the travel of the car. The construction of these switches is as follows: L (Fig-4) is the switch magnetand M is its movable armature pivotally secured at a and normally withdrawn from the magnet by a spring b. This armature carries the movable contact c which is adapted to contactwith the springs d d when the mag- .when the magnet is energized and these two contacts form a normally open break N in the circuit of the switch magnet. The armature controls two other breaks O and P, the break O is normally open and is formed by the contact springg (which is moved by the insulating stud h on the armature) and the fixed contact/L'. The other break P is `normally closed,
itis formed by the two spring contacts jk' which are brought in contact with each other when the armature is retracted by the insuv lating stud h on the armature.
The switches are connected lin a manner/to form two systems, one system operates as will be afterward more fully explained in the travel of the car from left to right to connectevery other section of the working conductor with the power line and the other system op- IOO crates in the same manner with the intermediate section when the car travels from right to left.
In the drawings H to H5 indicate the sections of the working conductor which are operated by one system of switches when the l car travels toward the right and HI to I-IV indicate the alternate sections which are operated by the other system of switches when the car travels toward the left.
In the drawings in Fig. 1 the first three switches of each system are shown, they are correspondingly distinguished by the use of I Italian and Roman numerals respectively.
The manner in which the switches are connected I will now explain by referring first` specifically to the switch K2 which is one of ythe switches of' the system which controls the rail sections H', H2, H3, &c. The fixed contact e -of the break J of this switch is connected Yto Q Vthe rail lH2 and the armature is connected to `'tl1epowerline(]. This connection forms the y feeder Ifor thelrail section H2w'hen the break .I is closed. The magnet L of the switch K2i has oneterminal of its coil connected th rough t Athe wire Z withthe fixed contact of thebreaki and AJthe other terminal is connected by way t ofthe wire m to one contact of the break P Aof Jthe nekt succeeding 'like switch K2, and ,t thence bl wire n from the other contact of f said brea to the lead E. The break O of the switch K2 has its spring contact connected l by wires o to -thelfixed contact'of the breakN` of Athe next succeeding like switch K3 and the nfixed contactof the break O isconnected by;J wire Lp to the yfixed contact of the break lfl`he^`other switches of the systemto whichthe Q switch '1K'2 belongs are connected in like man-1 ner from the #first -to the last switch, with this dierence'that in ythe last switch (which is; represented in the drawings by the switch Kif shown fin dotted lines) the break O may be omitted as its connections cannot be coin-l' pleted; also the connection 'm of its magnet 1, coil is made directly with thelead E and thatt part of the 'feeder I connecting-the armature with the .power line is preferably omitted. Inthe :first switch the break P may be omit, ted'as its contacts remain unconnected, `but in addition the fixed contact of its break is electricallyconnected through the wire q with 'the lead E of the switch battery and a normally open manual switch or push button Q iswplaced in this connection. The car in`` order to `operate these switches in its travel from left'to `right is provided with two conntacts or brushes R R which are fixed to the,` ca rinsuch relation that one ofthe two brushes l will alwayslbe in contact with one of the sec-` tional `conductors which the switch systern controls. These contactsare electrically connected with each other and with the motor; circuit and they operate in connection with i 1thesw-itch system as follows: In starting the car 'from leftto right one of its branches R R l must be iucontact with the section I-I which` sectionlike all the rest is disconnected from the power line. Vhen the operator wants to start he touches the push button Q (which for this purpose is arranged preferably in close proximity to the break), this completes an electric circuit through the magnet L of the first switch `K by way of the connection q from lead E to fixed contactsl of break N, thence through coil of magnet and connection m to break P of switch K2 (which break is normally closed) and thence through connection n to lead E. The magnet L of switch K is now energized by the battery current and attracts itsarmature, this closes the break N and thereby closes the switch circuit of magnet K', also by wayof the feeder I from the power line C (which also represents the lead E) to the armature and thence through break N where it joins the other circuit. The actuating circuit of,'the switch K', is thus closed through two branches -and therefore the magnetL remains energized after the operator withdraws his finger from the push button. The'armature of switch K remaining thus attracted closes the break .I which connects the `conductor section I-I through the feeder I with the power line and the `car isthus enabled to proceed on its Way. Before the rear brush of the car, however, leaves the section H the :front brush touches the section H2, this immediately closes the actuating circuit of switch K2 by way of the power line (l, feeder I of switch K', section H', brushes R R to sectionI-l2, feeder I-of switch K2 to fixed contactof break J of said switch, thence through connection P back to break 0 of switch K (which is now closed) and through its connection o to fixed contact of `break N in K2., from there "through `magnetLandits connection m to break P in 'the switch K and from there to -lead E. The closing of this circuit enerlgizes the-magnet of switch K2 audits armature closes the breaks .I and N, the result is that thereby a newfpath is opened tothe battery current by way of the armature of switch K2 from the power line through break N, thence through magnet L and connection m to break P ot switch Kfand thence through connection n to lead E'. The battery current thlusycontinues "to flow through -the magnet of `switch K2 afterthe rearbrush of the car leaves the section H andthe car can proceed on its `travel bytakingthecurrent from the section H2 which is new connected with the power line through itsfeeder. Simultaneously with the closing of the breaks .I and N of switch K2 the -break Pis opened and as the battery current which energizes the magnet of switch K flows through said break, said magnet will `be cut out and therefore the switch K will be restored to its normal condition thus disconnecting the section H from the power line. The break O in switch K2 is now also closed and therefore as soon as the front brush of car touches the section H2, a switch actuatingcircuit will be closed through the magnet `of switch Ki precisely in same manner as described for switch K2, and simultaneously IIO v therewith the opening of the break P in switch K3 will cut out the magnet of switch K2 and thereby restore the parts to their normal condition. In this manner the car is enabled to travel along the track from left to right by the successive operation of the system of switches just described. At the last switchwhich is represented in Fig.V 1 by'switch K3, the armature is not connected with the power line and therefore the section H5 is lnot rendered active, but it may be connected and this last feeder may then be disconnected by amechanically or manually operated break, if desred. The other switch system operates in connection with the conductor sections HI HH, &c., and. the switches of this system are constructed and arranged to operate precisely in the manneras ythe switches of the other system except that, being connected in the reverse order, they operate in the .travel of the car from right tov left. The two systems of switches operateentirely independent of each other and thus. my invention is applicable to either single or double track roads without the slightest change. For a double track road, of course one track would be equipped with the conductor sections and switches adapted to operate with the car going in one direction and the other track would be equipped with the conductor section and switches operating the car in the opposite direction.
In practice the simplest vway for equipping a single track road would be to placethe sections of. the working conductor all in line with each other betweenthe rails of the track and-connect the sections alternately to the two systems of switches.
For surface roads I propose to use short conductor sections, so that each section during the interval in whichit is act-ive, is protected by the car. In this way no danger can arise and my system is 'thereby made safe tov be used on public streets and high-ways and the conductor sections may be` entirely eX- posed and level-with the surface of the permanent -way so as to form no obstruction.
In my system the wires may allbe carried under-ground and a single vconduit may accommodate them all, and the switches instead of being distributed along the line maybe arranged in any desired. accessible position.
In this and other respects my system may be modified in many ways'to suit particular requirements, I deem the above description,
however, sufiicient to enable any skilled electrician to apply my system and add such details as may be found necessary in practical use. vOne modification I will, however, mention in particular and this is shown in Fig. 3, in which K represents aswitch of theconstruction already described, and the modification consists in providing each switch with a second armature MI which acts in connection with the opposite pole of the magnet.A This armature controls a normally open break J', the fixed contact of which is connected to a sectional return conductor S, and the armaand thus the rail A is not needed to form the return conductor, which' obviously would increase the factor of safety in my system.
It will be seen that the break J will be closed and opened simultaneously with the t (by providing the car with suitable brushes) l break .I and thus when one section of the coni ductorH is connected to the power line, the corresponding section of the sectional return conductor S is simultaneously connected to the return conductor T to the dynamo.
I am aware that many obvious changes and 'alterations in the arrangement-of the system can be made andsubstituted for those hereinl shown and described without in the least departing from thenature and principle of my invention.l
WhatI claim as my invention is- 3 1. In an electric railway system, the combination with a continuous power line, of a Working conductor composed of sections normally disconnected from said powerline,aswitch line and a return switch line extending along the working conductor from a stationary source of electricity, an electro-magnet for each section of the working conductor, the armature of which is adapted to connect the section with the power-line and with the switch line, two energizing circuits for each magnet one connecting the section of the working conductor with thereturn switchA line through a normallyopen vand a normally closed break controlled by the next, adjacent magnets respectively, and. the other connecting the two switch lines through the said normally closed break of the other circuit and a normallyopen break controlled by the magnetY itself, and a contact on the ear adapted to connect two adjacent sections of the working conductor, substantially as described. n
l2. ln an electric railway system, the combination with a continuous power line, of a work- IOO IIO
ing conductor composed'of sections normally disconnected from said power-line, a contact on the car adapted to connect two adjacent sections in the travel of the car, a switch and` a return switch line extending along the working conductor froma stationary source of electricity, an electro-magnet for each section of the working conductor, the armature of which is adapted to connect the section with the power line and with the switch line,
-and two energizing circuits for each mag-net,
one connecting the section of the working conductor with the return switch line and including av normally closed break controlled by the `succeeding magnet and a normally open break controlled by the preceding magf netsand by a push button for the initial magnet, and the other circuit connecting the two switch lines and including the said normally closed break of the other circuit and 'a norlnally open break controlled by each magnet itself, substantially as described.
3. In an electric railway system,the combination with an insulated power line and an insulated return power-line, of two exposed working conductors composed of corresponding sections normally disconnected from the power lines and with which the cars are adapted to travel in multiple connection, a Contact on the car adapted to connect the adjacent ends of the sections of one of the working conductors, a switch line and a return switch-line extending along the working condnctors from a stationary source of electricity, an 'electro-magnet for each two corresponding sections of the working conductors, two armatures for each magnet, one adapted to connect the section of one working conductor to the return power line, and the other armature being adapted to connect the corresponding section of the'other working conductor to the power line, and to the switch line, two energizing circuits for each magnet,
`one connecting the sections of one working `conductor (that which is adapted to be con-l nected with the switch line) with the return switch line includinganormally closed break i and a normally open break respectively controlled by the adjacent magnets, and the other energizing `circuit connecting the switch lines and including the norlnally closed break ot' the other circuit and a normally open break controlledfby each magnet itself, substantially `as described.
et. In an electric railway system, the combination with a power-line, of a working conductor composed of sections normally disconnected from said power-line,a contact on the `car adapted to connect one section with the adjacentsection of said working conductor in the travel of the car, a switch line and a return switch line extending along the working conductor from a stationary source of electricity, a switch magnet for each section of the working conductor, the armatures of each of which are adapted to connect said section with the power-line and with the switch line, and two energizing circuits for each magnet, one adapted to connect the magnet between the return switch line and its section of the working conductor and including a normally open and a normally working conductor composed ot' sections normally disconnected from said power-line, a contact on the car adapted to connect the ends of adjoining sections ot' the working conductor, a switch magnet for -each section of the working conductor the armature of which is adapted to connect the section with the power line, a source of electricity adapted to operate said switches and having one pole connected to the power-line and the other to a return switch line` extending along the power-line, and connections whereby each magnet is comprised in two circuits, one between the return switch conductor and the section ot the working conductor, which the magnet controls, and including a normally open and a normally closed break controlled respectively by the magnets of the adjacent sections and the other circuit between the power-line and the switch return line and including the said normally closed break of the other circuit and a normally open break controlled by the magnctitself, substantially as described.
G. In an electric railway system, the combination of two working conductors each composed of corresponding sections, a continuous insulated power-line and a continuous insulated return power-line, both normally disconnected from said working conductors, cars adapted to travelin multiple connection with corresponding sections of the two working conductors and provided with a contact or contacts adapted to connect the adjoining ends of the sections of one of the working conductors, a switch magnet for each two corresponding sections of `the working conductor provided with two armatures one adapted to connect the sections of one of the working conductors with the power line and the other adapted to connect the corresponding section of the other conductor withthe return powerline, a source ot' electricity adapted to oporate said switches and having one pole connected tothe power-line and the otherto a return switch line extending along the powerline, and connections whereby each magnet is comprised in two circuits, one between the return switch conductor and the section of the working conductors which the magnet is adapted to connect with thepower-line and including a normally open and a normally closed break controlled respectively bythe magnets of the adjacent sections and the other circuit between the power-line and the switch return line and including the said normally closed break of the other circuit and a normally open break controlled by the magnet itself, substantially as described.
In testimony whereof I athx my signature in presence of two witnesses.
THOMAS HARRIS.
IOCI
IIO
US521711D Supply system for electric railways Expired - Lifetime US521711A (en)

Publications (1)

Publication Number Publication Date
US521711A true US521711A (en) 1894-06-19

Family

ID=2590507

Family Applications (1)

Application Number Title Priority Date Filing Date
US521711D Expired - Lifetime US521711A (en) Supply system for electric railways

Country Status (1)

Country Link
US (1) US521711A (en)

Similar Documents

Publication Publication Date Title
US521711A (en) Supply system for electric railways
US493623A (en) Ments
US1151720A (en) Electric railway signal system.
US537197A (en) Supply system for electric railways
US889561A (en) Signal system for railways.
US700128A (en) Electric railway.
US537415A (en) Supply system for electric railways
US574953A (en) Electrical signal system
US490248A (en) harris
US540859A (en) Electric railroad signal
US1112473A (en) Electric signal system for railways.
US1130353A (en) System of automatic block-signaling.
US484919A (en) Electric-railway system
US681780A (en) Signal for electric railroads.
US551334A (en) Robert lundell
US386541A (en) Edwabd b
US530798A (en) Railway-signal
US762370A (en) Electric signaling system.
US757768A (en) Signal apparatus.
US635765A (en) Electric signal.
US782884A (en) Electric signaling apparatus for railways.
US1129143A (en) System of automatic block-signaling for electric railways.
US555509A (en) Electric railway
US551537A (en) Closed-conduit system for electric railways
US540653A (en) Supply system for electric railways