US900273A - Electric railway signal system. - Google Patents

Electric railway signal system. Download PDF


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US900273A US37773007A US1907377730A US900273A US 900273 A US900273 A US 900273A US 37773007 A US37773007 A US 37773007A US 1907377730 A US1907377730 A US 1907377730A US 900273 A US900273 A US 900273A
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Thomas M Freeble
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Thomas M Freeble
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    • B61L3/00Devices along the route for controlling devices on the vehicle or vehicle train, e.g. to release brake, to operate a warning signal
    • B61L3/16Continuous control along the route
    • B61L3/18Continuous control along the route using electric current passing between devices along the route and devices on the vehicle or vehicle train
    • B61L3/185Continuous control along the route using electric current passing between devices along the route and devices on the vehicle or vehicle train using separate conductors




900,273; I Patented 001:. 6, 1908.


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900,273. S Patented 001;. 6, 1908.


D S Q N N l 1 m I w v amaenfo'a flai/vaawaeila 13% h: gases T. M. FREEBLE. ELEGTRIG RAILWAY SIGNAL SYSTEM.






Patented Oct. 6, 1908.





, Patented Oct. 6, 1908.





To all whom it may concern."

Be it known that I, THOMAS M. FREEBLE,

citizen of the United States, residing at Latrobe, in the county of Westmoreland and State of Pennsylvania, have invented certain new and useful Improvements in Electric generators located on the locomotives, cars Railway Signal Systems, of which the following is a specification.

My invention relates to electric railway signal systems, and particularly to that class thereof, known as cab signal systems, wherein signals are operated in the locomotive or carfthe movements of which are to be controlled and regulated.

In the system herein described the current for the operation of the signals and other safety devices of the system is supplied by or trains themselves. Track-circuits are used, as hereinafter described, and the system comprises means whereby not only are proper signals displayed automatically, upon occasion, but also the brakes are set and power turned off automatically.

The objects of my invention are to im-' prove and simplify automatic railway signal systems,-to avoid normally-energized track circuits with consequent multiplication .of low-voltage generators (usually primary batteries), to economize current by energizing those circuits only which are in the immediate vicinity of the train or trains to be protected, to display the signals where they may be seen to best advantage, to avoid accident in case of neglect to observe signal indications by automatically cutting off power and applying the brakes, to make the system relatively simple, easily understood, and

- easily applied, to render the mechanism required simple and efficient, and enerally, to make the system simple, reliab e, inexpensive in operation and maintenance, and adaptable to modern conditions of railway operation.

I will now proceed to describe my invention with reference to the accompanying drawings, in which certain forms of apparatus and certain circuits embodying my invention are illustrated, and will then the novel features in claims.

In the said drawings: Figure 1 shows in diagrammatic elevation-the parts of my system designed to be mounted upon a car or the like, the said parts being in this instance shown mounted upon and arranged to control a steam locomotive; though they may point out Specification of Letters Patent.

' Application filed June 7, 1907. Serial No. 377,730.

Patented Oct. 6, 1908.

obviously be mounted upon an electric locomotive, a motor car, or any car of a train. Fig. 2 is a diagram showing the track circuits and other circuits which may beemployed in the case of a-sin'gle-track railway. Fig. 3 is a diagram showing the track circuits and other circuits which may be employed in the case of a double-track railway. Fig. 4 is another diagrammatic view illustrating the ciraSingle-track railway. Fig. 5 is a perspective view showing the track rails and signal ralls of a sin le-track system and the electrical connection of the track and signal rails of a block. Fi 6 is a detail sectional elevation showing t e contact device for operating the brakes automatically, and Fig. 7 is a detail side view of thesame. Fig. 8 shows a detail section through the magnet of the brake-setting device. Fi 9 shows a detail perspective elevation of t e rail-contact device carried by the locomotive or car to be controlled by the signal system, and of the means for holding said contact device against the corresponding rails. Fi 10 is a detail elevation of the alarm-whist e operating device. Fig. 11 is a diagram showing the connections of the signal lamps hereinafter mentioned.- Fig. 12 is a diagrammatic plan view showing means for operating the throttlelever or controller-handle automatically.

Referring now to the drawings, and at first to Figs. 1, 2 and 3, numeral 1 designates an electric generator (in this instance shown as a dynamo driven by a steam turbine 2, the generating set corresponding generally to generatin sets used for operating electric headlights, t ough arranged to produce current of voltage suitable for railway signal work) mounted upon a steam locomotive and arranged to supply current to the signal circuits, as hereinafterdescribed.

3 designates a rail-contact device likewise carried by saidlocomotive and arranged to suitable guide 5 carried by the pilot onother convenient part of .the locomotive or car, and having secured to it a suitable truck 6 pro vided with one or more contact-wheels 7. A fluid-pressure-actuated device 8 is arranged to press said rail-contact device down upon the corresponding. rails, or to raise it therecuits which may be employed at a switch of from, at will, being provided with pipes 9 and 10 leading to a suitable source of fluid under pressure (for example the engine boiler or the tank of the air brake equipment); said pipes controlled by a suitable valve 11, whereby either of said pipes may be con; nected to sup ly at will and the other connected to ex aust, so raising or lowering the contact device 3, as desired. When said device is down, it is held down elastically, owing to the elastic nature of the fluid holding it down, and hence the device accommodates itself automatically to inequalities of the line of rails with which it contacts.

For convenience in properly insulating the electric circuits, I prefer to insulate the guide 5 and fiuidressure-actuated device 8 from the frame 0 the locomotive, and to this end provide insulation 12 between guide 5 and the part of the locomotive to which same is secured, and insulatin couplings 13 in pipes 9 and 10. This enab es me to lead a conductor 14 direct from one pole ofthe generator to the bracket 15 forming'a part of guide 5, whence the current passes directly to the slide 4, wheels 7, and the rails upon which said wheels run.

On single-track roads I commonly provide each locomotive or car to which my invention is applied with two contact devices 3, one for each of the two signal-conductor rails provided in such'case, one such contact device being raised out of contact with the rail and the other depressed into such contact.

At some convenient point, preferably the engine cab in the case of a steam or electric locomotive, I provide a visual signal, an alarm whistle and means for actuating it, and means for closing the throttle valve or operating in an e uivalent manner any other controller with w ich the locomotive or car may be equip ed; and I further provide means for app ying the power brakes with which trains are now usually equipped.

Referring now to Fig. 2, I show in said figure two trains, A and B, each supposed to have a signal-equi ment substantially like that already descri ed with reference to Fig. 1. 17 and 18 designate the track rails, one of which, 17, is electrically continuous, extending unbroken electrically from block to block, while the other, 18, is divided into blocks of convenient length; This figure showing a single-track system, that is, a system over which trains move in both directions, ,1 provide, in addition to said track rails, two other track conductors, 19 and 20, which preferably are rails of suitable size and section supported upon the ties and located parallel with the track rails. These signal-rails, 19 and 20, are divided into blocks corresponding to the blocks of rail 18. In

Fig. 2 I have shown the track divided, as described, into four blocks, which I have designated respectively, C, D, E and F.

For convenience of illustration I have designated the current generators on trains A and B by the conventional designation of an electric battery, and have em loyed' the conventional illustration of an e ectric bell to represent the various signal, power-controlling and brake-applying devices of such trains. The'drawing shows trains A and B on adjacent blocks. It is assumed that both trains are moving in the same direction, viz., clockwise, for which reason the contact devices 3 of both trains are in contact with the inner signal conductor, 20. If either train were to move in the opposite direction, its track-circuit contact device would be in contact with the signal conductor 19 instead of signal conductor 20.

Considering the circuit from train A first,

said circuit passes from the generator 1 of that train through contact device 3 of that train to signal conductor 20 of block C, where the circuit ends. Starting from the other pole of the generator, the circuit passes through the signal and controlling devices of the train (represented in the diagram by the electric bell 21) and through the wheels of thetrain to the track rail 18; but since the circuit is incomplete on the other side of the battery, it is unnecessary to trace the circuits from the battery of train A further. There being no complete circuit from battery 1 of train A, or through controllin devices 21, train A is free to move from bl ock C to block D.

Considering now the circuit from train B, the circuit asses from the generator 1 of that train t rough contact device 3 to the signal conductor 20 of block D, thence by conductor 22 at the end of block D to the rail 18 of block C, thence through the wheels and axles of train A to the continuous rail 17 thence back throu h said rail 17 to block D and through the w eels and axlesof train B signal and controlling devices, 21, of train B, and to the o osite pole of generator 1 of that train. his circuit being complete, signal and controlling devices 21 are operated, and continue to be operated so long as trains A and B remain on adjacent track blocks, train B being thereby held in block D, while train A is free to proceed. As soon as train A passes from block G into block F the circuit through the signal and controlling deisclear, and hence train B, though blocked as to movement into block C, is free to move 1nto block'E. If train A were to seek to 55 the main track on to said' switch, contact of move into block D, assoon as its contact device 3' was shifted into contact with conductor 19 a circuit would be completed through.

continuous track rail 17 to block D, the wheels and axles of train B, the track rail 18 of block- D, conductor 23, and signal conductor 19 of block C and contact device 3 and signal and safety device21 back to the generator 1- of train A. It will be seen that each signal conductor, 19 or 20, of each block, is connected to track rail 18 of the block next beyond in the direction of motion to which such signal rail corresponds.

Fig. 3 shows the circuits-for the two tracks of a double-track system; one track rail of each trackbeing continuous, as shown, the other being divided into blocksgcorres 0nding to the-blocks in which the signal rai is divided, each signal rail beingconnectedto the track rail of the block next beyond. The circuits are the same as described above except that each track has only one signal conductor, since trains normally move on each track in one direction only.

At switches I- 'rovide means whereby unless all cars on tlhe switch are well beyond the clearance line the signals and controlling devices of an approaching train are operated the sameas if such car rojecting within the clearance line were on t 'e main track. This is illustrated in Fig. 4, which shows, for the main track blocks G, H and I, the same circuits as shown in Fig. 2, viz singletrack circuits. Numerals-24 and 25-designate the switch rails, in one ofwhich is 9.11 msulated' section 26, connected to .main track rail 18 andat such distance from the main track that the wheels of any car on the side track or switch whichis so near the main track as to project within the clearance line, will be on-.such insulated section; said section 26 being, insulated from the movable switchpoint, 27, which is connected to main track rail 17, as shown. Other short insulated track sections, 28 and29, are provided where the switclrrail's intersect the signal-conductor 20, sothat wheels passing on or off the switch may not afiect the circuit passing through said signal conductor. Switch rail Misconnected to main line continuous rail 17. It will be seenthat when'wheels are on 'duces t e same electrical effect as if t rail 24 and insulated section 26 the electrical effect isprecisely the same asif said wheels wereon the maintrack block- H Furthermore, ifthe switch-is set to direct trains on switch oint 27 with main track rail-18 proere were atrain on block H.

The signal devices which, in the arrangement shown in the drawings, are providedin the cab or other suitable'part of the locomotiveor car, are aseries of signal lights, 30,

- and an alarm whistle 31 operated by a magnet 32. In addition I provide mechanism shown in-Fig. 1-2, and controlled by sip-magnet 33 for closing the throttle or other powercontroller, and I further provide means shown:

particularly in Figs. 7 and 8, and comprising. an electric clutch consisting. of an armature 34 and magnet 35 and spring 36, for

operating brake-applyin mechanism; The

ductor 42 to the magnet 35 of the brake-controlling electric clutch and thence to the metal of the locomotive.

The mechanism for operating the alarm whistle 31 is simple, and isillustrated indetail in Fig. 10. The action of the whistle is controlled, as usual, by a valve, 43, against the stem of which one arm of a bell-crank 44 is arranged to press, the other arm of said bell-crank being connected to a link 45,suitably guided, to an armature 46 of the whistle magnet, 32.

As shown in Fig. 11, the signal lights 30 are connected in multi le circuit. As so connected, each lamp is t e equivalent of all the others, and such others might be omitted; but I prefer to provide a plurality of signal lamps, so that in case one be broken or burn out the others may continue to o erate.

, The mechanism for turning o the power, '11. e., 'in asteam locomotive, closing thethrottle, is shown in detail in Fig. 12, and com rises a fiuid-pressure-o erated actuating evice, (pressure cylinder 47, the piston of which is connected by a rod 48 to a bellcrank 49' pivoted to the throttle-arm or controller-lever 50; said bell-crank being also connected to the latchiece 51 of said throttle armorcontrolling ever. A pipe 52, controlled by a valve 53,- is provided for admitting fluid under pressure to the front end ofsaid cylinder, so as to withdraw the latchpiece 51 and. then draw the throttle-lever toward said cylinder. ranged to be operated by the armature of the magnet 33.

The fluid under pressure for operating the whistle, for raising or lowering and pressing. down the track contact devices 3, and for operating the throttle-closing cylinder 47 may be drawn from the locomotive boiler, from the air-brake tank, or from any other convenient source. In general com ressed air is preferable for operatlng these evices, as itis not hot, 1s not sub ect to condensa- Said valve 53 is ar tion, creates no cloud of vapor when it escapes,

and is as available as steam on practically all present-day railway equi ments.

In order that the thrott e or other controller may not be held closed, but the power may be merely cut off so that positive action on the part of the operator is required to continue the running of the train, the circuit from throttle -control magnet 54 passes through a contact device 55, whereby the circuit through said magnet is brokenas soon as the throttle is completely closed. The operator may then open the throttle again, holding the contact device 55 0 en or otherwise preventing the automatic 0 osing of the throttle; which permits him to proceed with caution through the block, or to back out of the block.

Those who have observed the way a skilled engine runner applies the air brakes are aware that never, except in case of an emergency, are the brakes applied fully and held on hard from the very beginning; but instead the brake valve is opened momentarily and then closed, opened again and then again closed; and this operation is often repeated a number of times. In general it is not desirable that the automatic brake-operating device herein described shall produce an emergency application of the brakes; and therefore I provide means for simulating the actions of the skilled engine-runner in applying the brakes for an ordinary stop. The armature, 34, of the brake-clutch carries a cam 56, adapted to actuate the follower-lever 57, which in turn is adapted to actuate the controlling valve 58 of the brake apparatus. The side of the cam 56 is beveled, so that the follower will rise when the cam is pulled over by the magnet 35 while said follower is along side said cam. The brake clutch is mounted upon one driver-axle of the locomotive, current being transmitted to it through a brush 59 riding on a collector-ring 60 on the outside of the clutch; the other end of the clutch coil being connected to the axle itself and so to round.

It will be seen that when a circuit is comleted through the clutch magnet while the ocomotive is moving, the brake valve 58 will be alternately opened and closed, in practically the manner commonly followed when making service stops in normal operation of trains.

It will be apparent that an iron bar or like conducting object laid across the rails of a block will have the same effect on the signals and other safety devices of a train approaching that block as if another train were in that block; consequently it is easy for track inspectors or train men to hold trains from entering a block in case of necessity. Fur- I thermore, since it is practically certain that in case of a derailment of a train some metal part of the train will continue to sh ort-circuit the track circuit of that block, the system affords efficient protection in case of derailment.

What I claim is 1. A railway block signaling system comprising in combination track rails, one electrically continuous through a plurality of blocks, the other divided into block sections insulated from each other, a signal conductor divided into blocks insulated from each other and each connected to the insulated rail block section of the block next in advance and train-controlling means mounted on a railway vehicle on said track, and comprising a contact device adapted to make contact with such signal conductor, and electricallyoperated signaling means, power-controlling means and brake-applying means and a generator therefor on said vehicle, and a perm anently closed circuit extending from said contact device through said generator and controlling means to a part of said vehicle adapted to contact with the track rails, said circuit being normally open as a whole and arranged to be completed through the wheels and axles of any railway vehicle which may occupy the block in advance.

2. In a railway si naling system, means for automatically app ying train brakes comprising a brake-applying valve, means for opening and closing same intermittently Y comprising a driving member arranged to be driven automatically by means connected to an axle'of the train while the train is in motion, and electrically-controlled means controlling the drivin of said member, and automatic block-signa ing means controlling the operation thereof.

3. In a railway signaling system, means for automatically applying train brakes comprising a brake-applying valve, a cam on one of the train axles for opening and closing said valve intermittently, an electric clutch con trolling said cam, and automatic block-signaling means comprising a circuit for energizing said clutch.

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


US37773007A 1907-06-07 1907-06-07 Electric railway signal system. Expired - Lifetime US900273A (en)

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