US1485563A

US1485563A - Train-controlling system

Info

Publication number: US1485563A
Application number: US544259A
Authority: US
Inventors: Harold A Maxfield
Original assignee: EZRA P WATERHOUSE
Current assignee: EZRA P WATERHOUSE
Priority date: 1922-03-16
Filing date: 1922-03-16
Publication date: 1924-03-04
Anticipated expiration: 1941-03-04

Description

H. A. MAXFIELD TRAIN CONTROLLING SYSTEM 1.922 8 she ts-sheet 1 Filed March 16.

Mamh' 4 1924.

' H. A. MAXFIELD TRAIN GONTRIOLLINQ SYSTEM 8 Sheets-Sheet 2 Filed March 16. 1922 March 4 @9240 H. A. MAXFIELD TRAIN CONTROLLING SYSTEM Filed March 16.

, 8 Sheets-Sheet March 4, 1924. Il;4g85,563

H. A. MAXFIELD TRAIN CONTROLLING SYSTEM H. A. MAXFIELD TRAIN CONTROLLING SYSTEM Filed March 16. 1922 8 Sheets-Sheet ,5

Maurch 4 11924;

' 1,485,563 H. A. MAXFIELD TRAIN CONTROLLING SYSTEM Filed March 16. 1922 Sheets-Sheet e A ma 4W March 4 1924.

Filed March 16. 8 Sheets-Sheet March 4 1924.

H. A. MAXE-IELD TRAI N CONTROLLING SYSTEM Filed March 16, 1922 8 Shes t 8 Patented Mar, 4, i924,

teases rarest sates,

HAROLD A. MAXFIELD, OF WORCESTER, L'IASSACHUSETTS, ASSIGNOR TO EZRA P.

W'AJIEJERI-IOUSE, OF WORCESTER, IEASSACHUSETTS.

TRAIN-CONTRQLLING SYSTEM.

Application filed March 16, 1922.

To all whom t't may concern.

Be it known that I, HAROLD A. MAXFIELD, a citizen of the United States, and a resident of Worcester, in the county of Worcester and State of Massachusetts, have invented a new and useful Improvement in Train-Controlling Systems, of which the following is a specification.

My invention, which is an improvement on the systems disclosed in the following United States Letters Patent issued to the Orcutt Automatic Train Control Company, viz, Or-

cutt, No. 1,285,345, November 19, 1918, La'

Count, No. 1,336,?165, April 13, 1920, and Prince and La Count, Nos. 1,336,484. April 13, 1920, and 1,342,572, June 8, 1920, to all of which, as well as to Patent No. 1,285,246 issued to said company November 19, 1918, on the application of Eldridge I. La Count, reference may be made for various details of construction not necessary to be specifically set forth herein, relates to systems for preventing railroad accidents such as collisions, derailments, running on to open switches, etc., by means of electrical apparatus and circuits carried by the train and arranged to cooperate through track-connected contactmembers located in the block-section in which the train is running with one of the advance blocks, for example the block next ahead; and its general object is to improve and simplify said systems and to increase the efficiency of the same.

In such train controlling systems a nor mally-energized train-carried air-brake-controlling electromagnet is deenergized and the air brakes automatically applied when an advance block such as the block next ahead of that in which the train is running has been rendered unsafe from any cause as by a broken rail, an open switch or another traintherein; or when the road-bed circuit of such advance block is opened; or when a train circuit is broken or the train apparatus short circuited or otherwise rendered incapable of properly functioning.

After such automatic application of the air brakes, the operation of the brake-releasing valve, which is an adjunct to the envineers air-brake valve and is automaticaly locked in running position when the train speed equals or exceeds a predetermined rate, will effect the release of the brakes, either after the train has been brought to a stand- Serial No. 544,259.

still or when its speed has been reduced below said predetermined rate, and thereafter in either case the train is automatically prevented from attaining a speed equaling or exceeding such predetermined rate until it passes out of the block the condition of which caused the application of the brakes and then only in the event that the next block ahead is safe.

While it has been demonstrated that the systems aforesaid will properly perform their intended functions under conditions of actual practice, they nevertheless involve certain complexities, the elimination of which constitutes the general object of the present invention. For example, in said systems, the train-carried circuits are connected to certain track circuits and apparatus by means of at least two and sometimes three or four contact shoes arranged to cooperate with at least two and sometimes three or four ramps or contact plates arranged beside the track in each block, at least one of said ramps being connected by an overhead wire to a track switch located near the farther end of the block ahead of that in which the ramp is placed.

A particular object of my invention is to provide a train controlling system wherein the train-carried circuits are connected to the rails of the block in advance of that in which the train is running solely by means of a single train-carried contact member arranged to cooperate with a single track-connected contact member in each block and whereby the air brakes will be automatically applied, and the train either brought to a standstill or its speed reduced below a given rate, when such advance block has been rendered unsafe, and whereby, also, the speed of the train, after such automatic application of the air brakes, is automatically main tained at less than said rate until the passage of said train out of the unsafe block.

Another object of my invention is to dispense with the track switch located near the farther end of each block whereby the circuit of the air-brake-controlling magnet is controlled by substituting therefor at the farther end of each block an electrical conductor which may be a resistance connecting the section of the sectional rail of said block with the electricallycontinuous rail, and a train-carried excess-current magnet connected to and disconnected from said resistance at a given point in every block by the traincarried and track-connected contact members, said excess-current magnet actuating a switch which controls the circuit of the airbrake-controlling magnet, whereby the cost of the system is greatly reduced, the chances of failure in action diminished and the amount of power required for operation decreased.

Another object of my invention is to reduce and simplify the train-carried circuits to render the system more positive in operation and less liable to fail in action.

A further object of my invention is to provide means for testing whether a railroad switch has been thrown completely one way or the other, to lock said switch from the block in the rear of that in which it is located if it has been properly thrown, to unlock the same from a point near the switch, and to automatically apply the brakes if said switch has not been properly set, all by the cooperation of the train-carried circuits and road-bed circuits.

\Vith the foregoing and other objects in view my invention comprises an air-brakecontrolling magnet normally energized by a train-carried source of electrical energy and means, consisting solely of a single traincarried contact member electrically connected with the circuit of said magnet and arranged for cooperation with a track-connected contact member located in the block in which the train is running and electrically connected with the rearward end of the sectional rail of the block next in advance, for momentarily breaking said circuit at a point in the block in which the train is running and simultaneously connecting the same in series with the rails of the block next in advance, whereby the circuit of said magnet will be opened if said block is unsafe for any of the reasons given above, said magnet deenergized and the brakes applied to bring the train to a full stop or reduce the speed thereof to a safe rate. It comprises also a speed-control switch having a magnet for moving the same to such position as to open the circuit of the air-brake-controlling magnet, and a magnet for resetting the same to its normal position, the circuit of the resetting magnet being normally open, and means whereby said circuit is closed through the rails of the block next ahead of that in which the train is traveling when such block is safe, said means comprising the aforesaid train-carried contact member normally in electrical connection with the circuit of the air-brake-controlling magnet.

By means of the two component parts of the invention mentioned above a single train-carried contact member is made to perform functions which in the systems disclosed in the patents aforesaid required two train-carried contact members, viz., the functions of looping the train-carried circuits into the rails of the block ahead of that in which the train is traveling for the purpose of testing said block, and stopping the train if said block is unsafe or controlling the speed thereof.

My invention comprises also means for electrically connecting the farther end of each section of the sectional rail with the continuous rail, such means preferably including a resistance approximately equal to a resistance normally included in the circuit of the air-brake-controlling magnet, and means electrically connecting each t ackconnected contact member with the rearward end of the section of the sectional rail neXt in advance of the section between the ends of which said contact member is located, together with an excess-current magnet controlling a switch which normally closes the circuit of the air-brake-controlling magnet, the circuit of said excess-current magnet being closed once in every block through the rails of the block next in advance of that in which the train is running, whereby should said resistance be short circuited by a train in said block, said excess-current magnet will cause said switch to break the circuit of the air-brake-controlling magnet and the brakes thereby will be applied.

By means of this feature the cost of the system is greatly reduced by the elimination of a track switch at the end of each block section, the amount of power required for operating the system is decreased and the system is rendered more positive in action. Furthermore by means of said feature and those already mentioned the train-carried circuits, especially those which relate to the speed controlling apparatus, are substantially reduced and simplified.

My invention further comprises electromagnetic switch-locking mechanism con trolled by the cooperation of the train carried circuits and road-bed circuits at a point in the block preceding that in which the switch is located, switch-unlocking means controlled by the cooperation of said circuits at a point near the switch, and an electric switch actuated by said mechanism whereby the eletrical continuity of the sectional rail of the block in which the switch is placed will be broken, if the switch has not been properly set and the brakes automatically applied.

Various other features of novelty will hereinafter be described and particularly set forth in the appended claims.

The drawings which accompany and form a part of this specification diagrammatically represent several embodiments of the inven tion; but it will be understood that both the apparatus and circuit arrangements therein conventionally shown may be materially modified by those skilled in the art without departing from the invention as defined by the appended claims.

In the drawings,-

Figure 1 shows a train controlling system with its several parts shown in the positions occupied when the train is running at or above a predetermined speed in an unoccu pied block, the track conditions of which are good, and before the train circuits are connected with the rails of the block next in ad vance;

Fig. 2 shows the system when the train circuits are connected to the rails of the block next ahead of that in which the train is running, said block being clear and the track conditions good;

Fig. 3 shows the system when the train circuits are connected with the block next ahead, one or both of the rails thereof, or their electrical continuity being broken;

Fig. a shows the system when the train circuits are connected with the block next ahead which is occupied by another train, the airbrake-setting valve having the position occupied immediately before the de-energization of the air-brake-controlling magnet;

Fig. shows the system after the circuits have been disconnected from the occupied block next ahead and the train has been brought to a standstill, the air-brake-setting valve having the position occupied imme diately before the reenergization of the airbrake-controlling system;

Fig. 6 shows the system when the train is runing under control below a predetermined rate of speed in an occupied blocr;

Fig. 7 shows the system when the train circuits are connected to a safe block next ahead after it has run under control through a portion of the preceding block, the speed control switch being about to be reset;

Fig. 8 shows the system provided with circuits and apparatus for locking a railroad switch from a point in the bloclr in the rear of that in which such switch is located and for unlocking said switch from a point near the same, the parts being shown in the positions occupied immediately before the switch-locking apparatus has operated.

In the particular drawings selected for more fully disclosing my invention each block section, about one-half mile in length, consists of the rail 1, the joints of which are bonded to insure electrical continuity, and a rail 2, the component parts of which are also electrically bonded, but the sections of which are insulated from the

adjacent sections

2, 2". The forward end of each section of the sectional rail is electrically connected to the continuous rail preferably through the

resistance

3, 3. Located between the ends of each sectional rail and preferably at a point some distance from the forward end thereof, for example about one thousand feet, is a track-connected contact member 4:, a", said contact member being shown herein by way of example as a ramp or contact plate or rail arranged parallel to the track rails and adjacent to either one thereof so that a train-carried contact member will cooperate therewith during the passage of the train through the block. The

contact members

4, 4 are connected, respectively, to the rearward end of, the section of the sectional rail next in advance of the same by the

conductors

5, 5" preferably carried by the telegraph poles beside the track, or as hereinafter explained a portion of the sectional rail of the adjacent track may be used for this purpose.

The train equipment includes an adjunct to the engineers air-brake valve such for example as shown in Patent No. 1,2852% above referred to, a portion of said adjunct being represented in Fig. 1 and comprising a casing having a passageway 6 normally closed by the brake-setting valve 7 but open to the atmosphere through the passage 8 when said valve is oil its seat. Said adjunct comprises also a casing 9 enclosing a brakereleasing valve pneumatically operated and controlled by the handle 10, the partial rotation of which serves to connect the brakerele-asing valve chamber with a pipe connected to the main compressed air reservoir.

The brake-setting valve 7 is actuated by the air-brake-controlling magnet 11, said magnet preferably being of the sheathed, hollow-core solenoid type and having an armature 12 secured to its plunger 13 which carries the valve 7, said armature being movable between the lower end of the sheath 14 and the backstop 15.

The circuit of the train-controlling magnet is normally closed and includes a source of electrical energy such as the direct current generator 16 carried by the train.

Carried by or otherwise associated with the plunger of the air-brake-controlling magnet is a switch 17 herein shown as of the commutator type, said switch consisting of an insulation member 18 provided with two conducting rings 19, 20 with which the

brushes

21, 22 and 23, 24, respectively, are arranged to co-operate for the purpose of closing certain circuits through said rings.

An excess-current magnet 25 herein shown as having a normally-open circuit is so arranged that its armature 26 is normally held away from the enclosing sheath 27, in the present instance a spring 28 arranged in a cylinder 29 and adjustable by the screw 30 serving to maintain the armature 26 in the position shown and prevent the oscillation of the same by the vibration or swaying of the train, and the lowermost position of said armature being governed by the head or piston 31 arranged in said cylinder and attached to the upper end of the magnet plunger. Arranged for actuation by said excess-current magnet is a switch 32 consisting in the present instance of an insulation member 33 carrying a conducting ring 34 arranged for cooperation with the

brushes

35, 36.

A speed-control switch 37 consisting in the present instance of the plunger carrying the insulation member 38 and conducting ring 39 arranged for cooperation with the brushes 40, 41 is controlled by the actuating magnet 42 and the resetting magnet 43 which when energized attract the

armatures

44, 45 respectively.

Operatively connected by the bevel gear 46 with a rotating element of the engine is a centrifugally actuated switch 47, said switch in the present instance consisting of an insulating cylinder carrying the conducting rings 48, 49 arranged for cooperation, respectively, with the

brushes

50, 51 and 52, 53. The ring 49 is shown as adjustable longitudinally of the said insulation memher, the set screw 54 serving to hold the same in adjusted position, although it will readily be understood that said ring may be fixed and the

brushes

52, 53 arranged for adjustment longitudinally of said ring. In like manner the brushes 50, 51 and their cooperating conducting ring 48 are arranged for adjustment longitudinally of said insulating cylinder either by moving said ring with respect to the brushes or, conversely.

A switch 55 consisting in the present instance of an insulating member carrying the conducting rings 56, 57 both of which are electrically connected with the conducting rod 58 the lower end of which is always in electrical contact with the train-carried contact member 59 is arranged to be actuated by said contact member which as shown in Fig. 1 consists of a downwardly curved member of spring material fixed at one end to a portion 60 ot the locomotive and having its other end maintained by its own elas ticity against the stop 61 secured to the portion 62 of the locomotive. The

brushes

63, 64 are arranged "for cooperation with the conducting rings 56, 57 respectively. A locking magnet 65 is arranged to actuate its plunger 66 and force the same through registering apertures bored in the extensions of the handle 10 and easing 9 of the airbrake-releasing valve, said plunger falling by gravity against the backstop 67 upon the deenergization of said magnet and thereby unlocking said handle.

When the traincarried contact member 59 is of? the track-connected contact mem her 4 and the train is running under normal conditions there will be a circuit through the air-brakecontrolling magnet 11 as follows: From the positive terminal of the generator to

wires

68, 69, winding 11, wire 70,

brush 35, ring 34, brush 36, wire 71, brush 40, ring 39, brush 41,

wires

72, 80, rod 58, ring 56, brush 63, resistance 81, which is equal approximately to the

resistances

3, 3, and thence back to the negative terminal of the generator by the wire 82. The handlelock magnet 65 will be closed through the wire 68, winding 65, brush 52, ring 49, brush 53 and wire 83 connected to the negative terminal of the generator. As long as the train travels at a speed equal to or exceeding a predetermined rate the governor of the centrifugally-actuated switch maintains the conducting ring 54 in cooperation with the

brushes

52, 53 and thereby the circuit of the locking magnet is kept closed and the handle locked.

The circuit of the excess-current magnet 25 is open at the brush 64 in the arrange ment shown in Fig. 1 although it will be understood of course that the wire 84 if disconnected from the winding 43 may be connected to the wire or the rod 58 so as to maintain the normal energization of said magnet 25,the magnetic pull resulting from. such normal energization not being sufiicient to overcome the compression of the spring 28. There will be a circuit through the white or safety signal lamp 85 by way of the

wires

68, 69, 86, brush 21, ring 19, brush 22, lamp 85 and wires 87 82.

The circuits of the actuating magnet 42 and resetting magnet 43 of the speed-control switch are both open.

When the train-carried contact member 59 strikes and runs along the track-connected contact member 4, the switch 55 is raised to the position shown in Fig. 2, one of the insulating portions of said switch is brought against the brush 63 thereby breaking the normally-closed circuit of the air-brake-controlling magnet and simultaneously closing it through the block 2 next in advance of that in which the contact member 4 is located, and if said block 2 is clear and the track conditions good the resistance 3 at the end thereof, being the equivalent of the resistance 81 cut out of the circuit of said airbrake-controlling magnet by said switch 55, will prevent any substantial change in the current flowing through said magnet, and the valve 7 will be maintained on its seat. Under these conditions the circuit through the magnet 11 is from the positive terminal of the generator to the

wires

68, 69, winding 11, wire 70, ring 34, wire 71, ring 39,

wires

72, 80, rod 58, contact shoe 59, ramp 4, overhead wire 5, sectional rail 2, resistance 3, continuous rail 1 and thence back to the generator by way of the contact member 88, shown as one of the wheels of the locomotive, and the wire 82. The handle 10 will remain locked and the white light 85 will continue burning. There will be a circuit through the excess-current magnet 25 by way of the

wires

68, 69, 86, brush 21, ring 19, brush 22, winding 25,

wires

84, 89, brush 64, ring 57, rod 58, shoe 59, ramp 4, overhead wire 5, sectional rail 2, resistance 3, continuous rail 1, contact member 88 and wire 82. The magnet 25 is so designed that when the resistance 8 is included in its circuit as above pointed out the current flow therethrough is not suliiciently strong to cause the armature 26 to rise against the opposing force of the spring 28 so that the circuit of the airbrake-controlling magnet is maintained between the ring 34 and brushes 85 and 86. Conditions being normal the train passes out of section 2 and through section 2 at full speed.

If however block 2 should have been ren-' dered unsafe by a broken rail as indicated in Fig. 3 the air brakes will be automatically applied as soon as the train-carried contact member strikes the track-connected contact member 4, so that the train will either be brought to a full stop or its speed maintained below a predetermined rate. One or both of the rails of block 2 being assumed to be broken so as to destroy the electrical continuity of the circuit formed in part by said rails, the circuit of the air-brake-controlling magnet is opened at the point where the rail is broken whereupon the resulting deenergization of said magnet will cause the valve 7 to drop from its seat thereby effecting the application of the brakes in the manner set forth in Patent No. 1,285,246 above mentioned. The armature 12 falling back to the stop 15 car "ies the switch 17 to the position shown in Fig. 3 thereby breaking the circuit of the white or safety signal lamp and closing the circuit of the red or danger signal lamp 89 through the

wires

68, 69, 86, 89, 90, said lamp 89', brush 23, ring 20, brush 24,

wires

87 and 82. The circuit of the excess-current magnet will be opened at the broken rail. The actuating magnet 42 of the speed-control switch 37 will be energized by way of the

wires

68, 69, 86, 90, 91, 92, winding 42, wires 93, 94, 95, ring 20,

wires

87 and 82, and thereupon said speed-control switch is shifted to the right as indicated in Fig. 3. This movement of the speed-control switch will bring one of the insulating portions of the speed-control switch in contact with the brushes 40, 41 thereby opening the circuit of the air-brake-controlling magnet at said switch. As soon as the shoe 59 runs off the ramp 4 the circuit of the air-brakecontrolling magnet would instantly be closed between the brush 63 and ring 56 were it not for the movement of the speed-control switch to the position shown in Fig. 3, and in such case the operation of the handle 10 would effect the release of the brakes so that the train could be driven through the dangerous block at full speed. Shortly after upon the application of the air brakes as aforesaid the centrifugally-actuated switch 47 will break the circuit of the handle-locking magnet 65 between the

brushes

52, 53 and the insulating cylinder upon which they are mounted. In Fig. 3 showing the position of the parts at the instant of cooperation of the

contact members

59 and 4, the speed of the train has not been sufficiently reduced to cause the centrifugal switch to drop to its lowermost position, such position being shown in Fig. 5; but this position will be assumed by said switch very shortly after the contact member 59 passes the contact member 4, and when this takes place, the handle is unlocked thereby permitting the release of the brakes. Means are provided whereby after the release of the brakes the train will be prevented from running at or above a predetermined rate, said means in the present instance consisting of the

shunt circuit

96, 97 connected around the speedcontrol switch and including the brushes 50, 51. When the train is stationary and up to the time it acquires a predetermined speed the said brushes 50, 51 will be in contact with the ring 48 thereby closing the shunt circuit aforesaid and, consequently, the circuit of the train-controlling magnet 11, the latter then being as follows :-

wires

68, 69, winding 11, ring 34, wires 71, 96, ring 48,

wires

97, 80, rod 58, ring-56, brush 63, resistance 81 and wire 82. The engineer having released the brakes by the operation of handle 10 may therefore run his train out of block 2 and through block 2 at a speed below said predetermined rate this being known as creeping up to the point of danger; but should he attemptto drive the train at a speed equal to or higher than said rate the circuit of the magnet 11 would be broken at the brushes 50, 51 and the brakes again automatically applied.

If the block 2 is occupied as indicated at 98 when the contact member 59 strikes the ramp 4 in the block in the rear of block 2, the brakes will be applied in the following manner: The excess-current magnet 25 will be over-energized by way of the

wires

68, 69, 86, brush 21, ring 19, brush 22, winding 25, wire 89, brush 64, ring 57, rod 58, shoe 59, ramp 4, overhead wire 5, the trucks 98 of the train in the block 2 (or any other metal lic obstruction on the rails which short circuits the resistance 3) rail 1, rolling contact 88 and wire 82, and will raise the switch 32 against the action, of the spring 28 thereby breaking the circuit of the air-brakecontrolling magnet between the

brushes

35, 36, and the insulation portion of said switch. Figure 4 shows the first instant of operation of the excess-current magnet, and immediately after the switch 32 actuated by said magnet has taken the position shown in Fig. 4, the valve 7 falls from its seat thereby applying the air brakes, the circuit of the tuating magnet 42 of the speed-control switch 37 is closed in the manner above set forth in connection with Fig. 8, thereby throwing said switch to the right, and shortly thereafter the centrifugally-actuated switch 47 will drop to its lowermost position, as shown in Fig. 5, thereby breaking the circuit of the locking magnet 65 and closing the

shunt

96, 97 around the speedcontrol switch.

As soon as the contact member 59 has passed over the ramp 4, as shown in Fig. 5, the circuit of the excess-current magnet is opened and the switch 32 drops to its normal position. When the speed of the train has been sufficiently reduced to close the

shunt

96, 97 around the speed-control magnet 37, the air-brake-controlling magnet will. be energized and the valve 7, shown off its seat in Fig. 5, will be raised to close the port controlled thereby. Figure 5 shows the first instant of closure of said

shunt

96, 97, following the deenergization of the excess-current magnet, the several moving parts being shown in the positions occupied immediately before the reenergization of the mag net 11. The positions of the moving parts shown in Fig. 5 are those which they assume when the train has been brought to a full stop (it being understood that said valve 7 is on its seat as soon. as the

shunt

96, 97 is closed) or while it is traveling under control at a safe speed out of the block 2 and into the unsafe block 2.

Figure 6 illustrates the system when the train is running under control below a pre determined speed through the occupied block 2. The air-brake-controlling valve is closed by way of the

shunt

96, 97 as above explained and therefore as long as the rate of travel is sufiiciently low to keep the ring 4-8 in contact with the brushes 50, 51 the train can proceed through said block; but as soon as it equals or exceeds the predeiermined rate the

shunt

96, 97 will be broken at the brushes 50, 51 thereby deenergizing the magnet 11 and automatically setting the brakes. It will be understood that upon the application of the brakes for any cause it is not necessar for the engineer to wait until the train has been brought to a full stop before releasing the same by means of the handle 10, for as soon as the speed of the train has been sufficiently reduced to break the. circuit of the locking magnet 65 at the

brushes

52, 53, thereby unlocking said handle, the brakes may be released in the manner above set forth, and the train driven at a safe speed below said predetermined rate.

After the train has run under control through a block the condition of which caused the application of the brakes, such as the block 2 the speed control switch 37 will be reset in the following manner:

efe

messes ring to Fig. 7 which shows the Contact member 59 on the ramp 4 connected by the overhead wire 5 to the rearward end of the sectional rail 2", the forward-end of which is connected to the continuous rail by the resistance 3", the circuit of the resetting magnet 43 is closed through the

wires

68, 69, 86, 99, 91, 92, winding 43, wire 89, brush 64-, ring 57, shoe 59, ramp 4', wire 5", rail 2", resistance 3", rail 1, rolling contact 88 and wire 82. The energization of said resetting magnet L3 will throw the speed-control switch 37 to the left, the position shown in Fig. 1, and will close the circuit of the airbrake-controlling magnet through the brushes 40, 41 and ring 39, whereupon the train is free to proceed at full speed, the circuit of said air-brakecontrolling magnet being new independent of the shunt 96. 97. Assuming that the train proceeds at full. speed upon. the resetting of the S1386Cl-0011- trol switch, the centrifugally-actuated switch 457 will assume the position shown in Fig. 1, said shunt will be opened and the handle 10 locked in running position. It will b understood of course that if the block 2" were not clear and the track conditions were not good the speed-control switch would not be reset and the operations above set forth in connection with Figs. 3 and. 4: would be carried out.

It will be noted. that the means whereby the normally-closed circuit of the air-brakecontrolling magnet is broken at a point in each. block and simultaneously connected in series with the rails of the block next in advance consist solely of the train-carried contact member 59 and the track-connected contact member 4 as distinguished from the systems shown in the patents above referred to in which at least two train-carried. contact shoes are required, one such shoe closing the circuit of a track switch located at or near the forward end of the block in advance of that in which the train is traveling whereupon if said block is clear and the track conditions good the second shoe cooperating with another ramp connects the air-brake-controlling magnet in series with a circuit consisting in part of the continuous rail, the sectional rail at no time forming a part of the circuit of said magnet; also that the train-carried contact member is connectec not only with the circuit of the airbrake-controlling magnet but also with the circuit of the magnetic means controlling the specd-control magnet, so that a single train-carried contact member performs the functions which require two such contact members in the system described in Patent 1,336,465 aforesaid; and also that the excess-current magnet is arranged to open the circuit of the air-brake-controlling magnet only when said access-current magnet is over-energized as distinguished from the system disclosed in Patent 1,285,345 aforesaid in which the magnet controlling the air-brake-controlling magnet is arranged to open the circuit of said air-brake-controlling magnet upon its under-energization as well as upon its over-energization, this requiring an impracticably-fine adjustment. By virtue of the elimination of the track magnets of the prior art, one at the forward end of every block and the substitution therefor of the track resistances 3 together with the employment of the excess-current magnet and the switch actuated thereby, the cost of the system is greatly reduced and its action is made more certain and positive, the only moving parts of the system being under the direct supervision of the engineer.

In Fig. 8 I show an adjunct to the system above described whereby the brakes willbe automatically applied when the train is in a given block if a rail switch in the block ahead is open, and whereby said switch may be locked in either position by the cooperation of the train and track circuits when the train is in the block in the rear of said switch and subsequently unlocked shortly before or immediately after the train passes the same. The ramp 99 placed a short distance in the rear of the ramp 4 located as above set forth some distance in the rear of the forward end of section 2 is connected by the wire 100 to the switch-locking magnet 101 the other terminal of which is connected to the continuous rail by the wire 102. Located near the rail switch and in the present instance shown as a short distance in the rear thereof, although obviously it might be placed a short distance forward of the same, is a ramp 103 connected by the wire 104 with the switch-unlocking magnet 105 the other terminal of which is connected to the continuous rail by said wire 102. A tuated by the plunger of the magnets 101, 105 is a switch 106 consisting in the present instance of an insulation member provided with a conducting ring 107 arranged for cooperation with the brushes 108, 109 which are connected by the wires 1-10, 111 respectively with the two

insulated portions

2, 2 of the sectional rail 2. For simplicity of illustration the track switch is represented as a stub switch 112 the rails of which are pivoted. at 113, the free ends of said rails sliding over the plates 11 1 electrically con nected with the rails of the forward portion of the section by the bonds 115. The bond 116 diagrammatically represents means for maintaining the electrical continuity of section 2", it being understood that in practice the frog will be so constructed as to render such bond unnecessary. By means of the lever 117 pivotally connected to the switch bar 118 and to the tie rod 119 pivoted to the two switch rails, the switch may be hrown to either position. The operation is as follows: When the shoe 59 encounters the ramp 99 there will be a circuit through the switch-locking magnet 101 from the positive terminal of the generator 16 by way of the

wires

68, 69, winding 11, ring 34, wire 71, ring 39,

wires

72, 80, rod 58, shoe 59, ramp 99, wire 100, winding 101, wire 102, rail 1, rolling contact 88 and wire 82. The resulting energization of said winding 101 will attract the shuttle armature 120 and throw the plunger 121 to the right so that if the switch is properly set the bolt will pass through one of the apertures 122 or 123 in the switch bar depending upon whether the switch is in main-line or switching position, respectively. It will be understood that the opening of the switch will not break the metallic continuity of the sectional rail 2 or of the continuous rail 1 so that the circuit of the air-brake-controlling magnet would not be opened when the contact member 59 encounters the ramp 4.- merely on account of the opening of the switch; but unless such switch is locked either in one position or the other, the airbrake-controlling -magnet will be deenergized and the brakes automatically applied as soon as the contact member 59 strikes the ramp 4 placed as aforesaid about one thousand feet in the rear of the block in which the switch is located. The energization of the switch-locking magnet 101 and the result ing movement of the plunger 121 to the right will close the shunt circuit 110, 111 through the brushes 108, 109 and the ring 107 thereby electrically connecting the two insulated. portions 2*, 2 of the sectional rail 2. Immediately thereafter the contact member 59 encounters the testing ramp t and the conditions will be identical with those above set forth in connection with Fig. 2 if block 2 is safe or those above explained in connection with Figs. 3 and 1 if said block is occupied or the rails thereof broken. If. however the rail switch should be open, that is, not properly thrown to one position or the other, the bolt 121 cannot enter either aperture 122, 123 and therefore the switch 106 cannot be moved to the position necessary for closing the shunt 110, 111. The electrical continuity of the sectional rail of block 2 being thus destroyed, the brakes will automatically be applied as soon as the shoe 59 encounters the ramp 4- in the manner above set forth in connection with Fig. 3, and the train brought to a full. stop or else prevented from passing through block 2 except at a speed lower than a predetermined rate.

When the contact member 59 cooperates ramp 103, wire 104i, winding 105, wire 102, rail 1, rolling contact 88 and wire 82, whereupon the shuttle armature 120 will be attracted by the electromagnet 105 and the plunger thrown to the left in the position shown in Fig. 8, thereby unlocking the rail road switch. Preferably the electromagnets 101, 105 and their shuttle armature 120 are constructed in the manner shown in Patent 1,285,345, the windings 101, 105 being stationary and the plunger to which the armature 120 is fixed having a sliding fit in the bores of the fixed cores around which said windings are wound.

The resistance of the switch-locking and unlocking magnets 101, 105 shown in Fig. 8 should have approximately the same value as the block resistance 3 or about one half of the total circuit resistance so that when the train-carried circuits are looped into the circuits of said magnets by the co-operation of the contact shoe with the ramps 99 and 103' respectively the effect will be substantially the same as when said train-carried circuits are looped into the circuit formed by the rails and the resistance 3 by the co-operation of the contact shoe and ramp 4:.

It will be noted that while three ramps are required in the system shown in Fig. 8, only one train-connected contact member wi ll suflice to perform the functions of the two contact shoes of the system disclosed in patent 1,285,345 and that the road-bed circuit arrangements of my system are much more simple than those of the system of said patent, and furthermore that the circuits of the switch-locking and unlocking magnets are independent of the switch 106 governing the electrical continuity of the insulating portions of the sectional rail.

Having thus described illustrative embodiments of my invention without however limiting the same thereto, what I claim and desire to secure by Letters Patent is 1. A train controlling system comprising in combination an electrically-continuous rail and a sectional rail, each section of which is electrically continuous but insulated from its adjacent sections, a source of electrical energy carried by the train, an air-brakecontrolling magnet normally energized by said source, and means whereby the normallyclosed circuit o'f'said magnet is broken at a point in the block in which the train is run ning and simultaneously connected in series with the rails of the block next in advance, said means consisting solely of a single traincarried contact member electrically connected with said circuit and a single track-connected contact member located in the block in which the train is running and electrically connected with the rearward end of the sectional rail of the block next in advance.

2. A train controlling system comp ising in combination an electrically-continuous rail and a sectional rail, each section of which is electrically continuous but insulated from its adjacent sections, a source of electrical energy carried by'the train, an air-brakecontrolling magnet normally energized by said source, electromagnetic means for reducing the speed of the train to less than a predetermined rate after the de-energization of said air-brake-controlling magnet and the resulting automatic application of the air brakes and for maintaining such speed at less than said rate during the passage of the train up to and out of the block the condi tion of which caused the application of the air brakes, means actuated by said air-brakecontrolling magnet for controlling said electromagnetic means, and means whereby the normally closed circuit of said air-brake-controlling magnet is broken at a point in the block in which the train is running and simultaneously connected in series with the rails of the block next in advance, said means consisting solely of a single train-carried contact member electrically connected with said circuit and a single track-connected contact member located in the block in which the train is running and electrically connected with the rearward end of the sectional rail of the block next in advance.

3. A train controlling system comprising in combination an electrically-continuous rail and a sectional rail, each section of which is electrically continuous but insulated from its adjacent sections, a source of electrical energy carried by the train, an air brake-controlling magnet normally energized by said source, a speed-control switch, an actuating magnet and a resetting magnet for causing said speed-control switch to open and close the circuit of said air-brake-controlling magnet, respectively, and means whereby the normally-closed circuit of said air-brake-controlling magnet is broken at a point in the block in which the train is running and simultaneously connected in series with the rails of the block next in advance, said means consisting solely of a single traincarried contact member electrically connected with said circuit and with the circuit of said resetting magnet and a single track-connected contact member located in the block in which the train is running and electrically connected with the rearward end of the sectional rail of the block next in advance.

4;. A train controlling system comprising in combination an electrically-continuous rail and a sectional rail, each section of which is electrically continuous but insulated from its adjacent sections, a source of electrical energy carried by the train, an airbrake-controlling magnet normally energized by said source, a speed-control switch, an actuating magnet and a resetting magnet for causing said speed-control switch to open and close the circuit of said air-brake-con' trolling magnet, respectively, a switch actuated by said air-brake-controlling magnet, for controlling the circuit of said actuating magnet, and means whereby the normally-closed circuit of said air-brakecontrolling magnet is broken at a point in the block in which the train is running and simultaneously connected in series with the rails of the block next in advance, said means consisting solely of a single train-carried contact member electrically connected with the circuits of said air-brakecontrolling magnet and said resetting magnet, and a single track-connected member located in the block in which the train is running and electrically connected with the rearward end oi? the sectional rail of the block next in advance.

5. A train controlling system comprising in combination an electrically-continuous rail and a sectional rail, each section of which is electrically continuous but insulated from its adjacent sections, a source of electrical energy carried by the train, an air-brake-controlling magnet normally energized by said source, a speed-control switch, an actuating magnet for causing said speedcon-trol switch to open the circuit of said air-brake-controlling magnet, a resetting magnet for causing said speed-control switch to close the circuit of said air-brake-contr'olling magnet, a single train-carried contact member connected with the circuit of said air-brake-controlling magnet and with the circuit of said resetting magnet, and a single track-connected contact member located in the block in which the train is running and electrically connected with the rearward end of the sectional rail of the block next in advance.

6. A train controlling system comprising in combination an electricallycontinuous rail and a sectional rail, each section of which is electrically continuous but insulated from its adjacent sections, a source of electrical energy carried by the train, an air-brake controlling magnet normally energized by said source, a speed-control switch, electro magnetic controlling means for said speedcontrol switch, a train-carried contact member, a track-connected contact member arranged for co-operation with said train-carried contact member and means electrically connecting said train-carried contact memher with the circuits of said air-brake-com trolling magnet and said electromagnetic controlling means.

7. A train controlling system comprising in combination an electrically-continuous rail and a sectional rail, each section of which is electrically continuous but insulated from its adjacent sections, a source of electrical energy carried by the train, an airbrake-controlling magnet normally energized by said source, a speed-control switch,

an actuating magnet and a resetting magnet for causing said speed-control switch to open and close the circuit of said air-brake-controlling magnet, respectively, a shunt circuit connected around said speed-control switch, means for closing said shunt circuit when the train is stationary or the speed thereof is less than a predetermined rate and thereby closing the circuit of said air-brake-controlling magnet after the same has been opened by said speed-control switch, and means whereby the normally-closed circuit of said air-brake-controlling magnet is broken at a point in the block in which the train is running and simultaneously connected in series with the rails of the block next in advance, said means consisting solely of a single train-carried contact member electrically connected with the circuits of said air-brakecontrolling magnet and said resetting magnet and a single track-connected contact member located in the block in which the train is running and electrically connected with the rearward end of the sectional rail of the block next in advance.

8. A train controlling system comprising in combination an electrically-continuous rail and a sectional rail, each section of which is electrically continuous but insulated from its adjacent sections, a source of electrical energy carried by the train, an airbrake-cont-rolling magnet normally energized by said source, a speed-control switch, an actuating magnet and a resetting magnet for causing said speed-control switch to open and close the circuit of said air-brakecontrolling magnet, respectively, a shunt circuit connected around said speed-control switch, a centrifugally actuated switch for closing said shunt circuit when the train is stationary or the speed thereof is less than a predetermined rate and thereby closing the circuit of said airbralie-controlling magnet after the same has been opened by said speed-control switch, and means whereby the normally-closed circuit of said air-brakecontrolling magnet is broken at a point in the block in which the train is running and simultaneously connected in series with the rails of the block next in advance, said means consisting solely of a single train-carried contact member electrically connected with the circuits of said air-brake-controlling magnet and said resetting magnet and a single track-connected contact member located in the block in which the train is running and electrically connected with the rearward end of the sectional rail of the block next in advance.

9. A train controlling system comprising in combination a source of electrical energy carried by the train, an air-brake-controlling magnet normally energized by said source, an excess-current magnet, a switch actuated by said excess-current magnet, said switch normally closing the circuit of said airbrake-controlling magnet and being ar ranged to open said circuit only when the current in said excess-current magnet exceeds a given intensity, and a switch actuated by said air-brake-controlling magnet, the last mentioned switch having its contacts connected in the circuit of said excess-current magnet.

10. A train controlling system comprising in combination a source of electrical energy carried by the train, an airbrake-controlling magnet normally energized by said source, an excess-current magnet, a switch actuated by said excess-current magnet, said switch controlling the circuit of said air-brake-controlling magnet, and a switch actuated by said air-brake-controlling magnet for con trolling the circuit of the excess-currei'it magnet 11. A train controlling system comprising in combination a source of electrical energy carried by the train, an air-brake-controlling magnet normally energized by said source, a second magnet, a switch actuated by said second magnet for controlling the circuit of the air-brake-controlling magnet, and a switch actuated by the air-brake-coir trolling magnet "for controlling the circuit of said second magnet.

12. A train controlling system comprising in combination a source of electrical energy carried by the train, an air-brakecontrolling magnet normally energized by said source, an excess-current magnet, a switch actuated by said excess-current mag net, said switch normally closing the circuit of said airbral :e-controlling magnet and being arranged to open said circuit only when the current in said excess-current magnet exceeds a given intensity, a speed-control switch normally closing the circuit of said air-brake-controlling magnet, a train-carried contact member, and a switch actuated by said train-carried contact member and normally closing the circuit of said air brake-controlling magnet.

13. A train controlling system compris ing in comt'nation a source oi electrical energy carried by the train, an air-brake controlling magnet normally energized by said source, an excess-current magnet, a switch actuated by said excess-current magnet, said switch normally closing the circuit of said airbrake-controlling magnet and being arranged to open said circuit only when the current in said excess-curent magnet exceeds a given intensity, a speedcont-rol switch normally closing the circuit or" said air-brake-controlling magnet, a shunt circuit connected around said speedcontrol switch, means for closing said shunt circuit when the train is stationary or the speed thereoi is less than a predetermined rate, a train-carried contact member and a switch actuated by said train-carried contact member and normally closing the circuit of said air-brakecontrolling magnet.

14. A train controlling system comprising in combination a source of electrical energy carried by the train, an air-brakecontrolling magnet normally energized by said source, a normally-open-circuited' excess-current magnet, and a switch actuated by said excess-current magnet, said switch normally cl sing the circuit of said airbrake-controlling magnet and being arranged to open said circuit only when the current in said excess-current magnet exceeds a given intensity.

train controlling system comprising in combination a source of electrical energy carried by the train, an air-brake-controlling magnet normally energized by said source, a normally-open-circuited excesscurrent magnet connected in parallel with said aii'--brake-controlling magnet, and a switch actuated by sain excess-current magnet, said switch normally closing the circuit of said air-bralte-controlling magnet and being arranged to open said circuit only when the current in said excesscurrent magnet exceeds a given intensity.

16. A train controlling system comprising in combination an electrically-continuous rail and a sectional rail, each section of which is electrically continuous but insulated from its adjacent sections, an electrical connection from the forward end of each section of said sectional rail to said continuous rail, a track-connected contact member located between the ends of each section of said sectional rail at a point some distance from the forward end thereof, means connecting each said contact member to the rearward end of the section oi said sectional rail next in advance of the same, a source of electrical energ 1 carried by the train, an air-brake-controlling magnet normally energized by said source, a .normally-open-circuited excess-current magnet, a switch actuated by said excess-current magnet, said switch normally closing the circuit of said air-brake-controlling magnet, and a traincarried contact member connected to the circuits of said air-brakecontrolling magnet and said excess-current magnet and arranged to co-operate with said track-connected contact member.

17. A train controlling system comprising in combination, a source of electrical ene y carried by the'train, an air-brakecontrolling magnet normally energized by said source, a normally-open-circuited excess-current magnet, a swi t-ch actuated by said excess-current magnet, said switch normally closing the circuit of said air-brake controlling magnet and being arranged to open said circuit only when the current in said excess-current magnet exceeds a given intensity, and means whereby the normallyopen circuit of said excess-current magnet is closed once in every block through conductors comprising the rails of the block next in advance.

18. A train controlling system comprising in combination an electrically-continuous rail and a sectional rail, each section of which is electrically continuous but insulat-ed from its adjacent sections, an electrical connection from the forward end of each section of said sectional rail to said continuous rail, a tracloconnected contact member located between the ends of each section of said sectional rail at a point some distance from the forward end thereof, means connecting each said contact member to the rearward end of the section of said sectional rail next in advance of the same, a source of electrical energy carried by the train, an air-brake-controlling magnet normally energized by said source, a normally-open-circuited excess-current magnet, a switch actuated by said excess-current magnet, said switch normally closing the circuit of said air-brake-controlling magnet, and means whereby the normally-open circuit of'said excess-current magnet is closed once in every block through the sectional rail of the block next in advance, said electrical conductor and said continuous rail.

19. A train controlling system comprising in combination an electrically-continuous rail and a sectional rail, each section of which is electrically continuous but insulated from its adjacent sections, an electrical connection from the forward end of each section of said sectional rail to said continuous rail, a track-connected contact member located between the ends of each section of said sectional rail at a point some distance from the forward end thereof, means connecting each said contact member to the rearward end of the section of said sectional rail next in advance of the same, a source of electrical energy carried by the train, an air-brakecontrolling magnet normally energized by said source, a normally-0pencircuited excess-current magnet, a switch actuated by said excess-current magnet, said switch normally closing the circuit or" said air-brakecontrolling magnet and being arranged to open said circuit only when the current in said excess-current magnet exceeds a given intensity, and a train-carried contact member connected to the circuit of said excesscurrent magnet and arranged to co-operate with said track-connected contact member.

20. A train controlling system comprising in combination a source of electrical energy carried by the train, an air-brake-controlling magnet normally energized by said source,

a normally-open-circuited excess-current magnet, a switch actuated by said excesscurrent magnet, sa d switch normally closing the circuit of said air-brake-controlling magnet and being arranged to open said circuit only when the current in said excesscurrent magnet exceeds a given intensity, and a switch actuated by said air-brakecontrolling magnet, the last mentioned switch having its contacts connected in the circuit of said excess-current magnet.

21. A train controlling system comprising in combination a source of electrical energy carried by the train, an air-brakecontrolling magnet normally energized by said source, a normally-open-circuited excess-current magnet, a switch actuated by said excess-current magnet, said switch controlling the circuit of said air-brake-controlling magnet, and a switch actuated by said air-brake-controlling magnet for controlling the circuit of the excess-current magnet.

22. A train controlling system comprising in combination a source of electrical energy carried by the train, an air-brakecontrolling magnet normally energized by said source, a normally-open-circuited excess-current magnet, a switch actuated by said excess-current magnet, said switch normally closing the circuit of said air-brakecontrolling magnet and being arranged to open said circuit only when the current in said excess-current magnet exceeds a given intensity, a speed-control switch normally closing the circuit of said air-brake-controlling magnet, a train-carried contact member, and a switch actuated by said traincarried contact member and normally closing the circuit of said air-brake-controlling magnet.

23. A train controlling system comprising in combination a source of electrical energy carried by the train, an air-brakecontrolling magnet normally energized by said source, a normally-open-circuite'd excess-current magnet, a switch actuated by said excess-current magnet, said switch normally closing the circuit of said air-brake controlling magnet and being arranged to open said circuit only when the current in said excess-current magnet exceeds a given intensity, a speed-control switch normally closing the circuit of said air-brake-controlling magnet, a shunt circuit connected around said speed-control switch, means for closing said shunt circuit when the train is stationary or the speed thereof is less than a predetermined rate, a train-carried con tact member and a switch actuated by said train-carried contact member and normally closing the circuit of said air-brake-controlling magnet.

24. A train controlling system comprising in combination a railroad switch, means for locking said railroad switch in main-line or switching position, a switch locking magnet for actuating said means in one direction, a

switch-unlocking magnet for actuating said means in the opposite direction, a traincarried source of electrical energy, and means for closing the circuit of said source of electrical energy through said switchlocking magnet at a point in the block in the rear of that in which said railroad switch is located and for closing said circuit through said switch-unlocking magnet at a point near said railroad switch, said means consisting solely of a single train-carried contact member, a traclceonnected contact member in the block in the rear of that in which said railroad switch is located and connected to said switclrlocking magnet and a track-connected contact member located at a point near said railroad switch and connected to said switch-unlocking magnet.

25. A train controlling system comprising in combination a railroad switch, means for locking said railroad switch in closed position from a point in the block in the rear of that in which said railroad switch is located, and means for unlocking said railroad switch from a point in the block in which said railroad switch is located, said means comprising a train-carried source of electrical energy, a track-connected contact member in the block in the rear of that in which said railroad switch is located, a track-connected contact member in the block in which said railroad switch is located, and a train-carried contact member arranged to co-operate with both of said track-connected contact members.

26. A. train controlling system comprising in combination an electrically-continuous rail and a sectional rail having a plurality of sections, each of which is electrically continuous but insulated from its adjacent sections, and one section divided into two insulated portions, said portions being insulated from the sections adjacent thereto, a

railroad switch in the block containing the divided sectional rail, said railroad switch being located in the advance portion thereof, a shunt circuit around the proximate ends of said insulated portions, a switch for opening and closing said shunt circuit, electromagnetic means for actuating said switch, the circuits of said electromagnetic means being independent of said shunt circuit, and means comprising a train-carried source of electrical energy for energizing said electromagnetic means.

27. A train controlling system comprising in combination an electrically-continuous rail and a sectional rail having a plurality of sections, each of which is electrically continuous but insulated from its adjacent sections, and one section divided into two insulated portions, said portions being insulated from the sections adjacent thereto,a railroad switch in the block containing the divided sectional rail, said railroad switch asses being located in the advance portion thereof, a shunt circuit around the proximate ends of said insulated portions, means for locking said railroad switch in main-line or switching position, a switch actuated by said means for opening and closing said shunt circuit, a switch-locking magnet for actuating said means in one direction and a switch-nnlocking magnet tor actuating said means in the opposite direction, the circuits of said switclulocking magnet and switch-unlocking magnet being independent of said shunt circuit, and means comprising a train-carried source of electrical energy for energizing said switch-locking magnet and switch-unlockin magnet.

28. a train controlling system comprising in combination an electrically-continuous rail and a sectional rail having a plurality of sections, each of which is electrically e0ntinuone but insulated from its adjacent sections, and one section divided into two insulated portions, said portions being insulated from the sections adjacent thereto, a railroad switch in the block containing the divided sectional rail, said railroad switch being located in the advance portion thereof, a block resistance electrically connected between the forward end of said advance por tion oi said divided sectional rail and said continuous rail, a track-connected contact member located in the block in the rear of that in which said switch is placed, means connecting said track-connected contact member to the rearward end of the rearward portion of the divided sectional rail, a shunt circuit around the proximate ends of said insulated portions of said divided sectional rail, means for locking said railroad switch in main-line or switching position, a switch actuated by said means for opening and closing said shunt circuit, a switch-locking magnet for actuating said means in one direction and a switch-unlocking magnet for actuating said means in the opposite direction, the circuits of said switch-locking magnet and switch-unlocking magnet being independent of said shunt circuit and the resistance of each of said magnets being substantially equal to that of said block resistance, a source of electrical energy carried by the train, an air-brass-controlling magnet normally energized by said source, and a traincarried contact member arranged to connect the circuit o1 said air-brake controlling magnet in series with said switch-locking magnet, said block resistance, and said switch-unlocking magnet, successively.

29. A train controlling system comprising in combination an electrically continuous rail and a sectional rail having a plurality of sections, each of which is electrically continuous but insulated from its adjacent sections, and one section divided into two in sulated portions, said portions being insu-