US1508413A

US1508413A - sasnett

Info

Publication number: US1508413A
Authority: US
Publication date: 1924-09-16
Anticipated expiration: 1941-09-16

Description

Sept-16. 1924. 1,508,413

E. c. SASNETT AUTOMATIC TRAIN CONTROLLING SYSTEM Filed June 12. 1923 4 Sheets-Sheet 1 vwemoz Sept. 16 {1924:

1,508,413 r; c. SASNETT AUTOMATIC TRAIN CONTR OLLING SYSTEM Filed June 12 1923 4 Sheets-Sheet 2 Sept. 16', 1924: 1 5083413 E. c. SASNETT AUTOMATIC TRAIN CONTROLLING SYSTEM Filed June 12, 1923 4 Sheets-Sheet 3 anueuko'z,

E. c. SASNETT AUTOMATIOTRAIN CONTROLLING SYSTEM Filed June 12, 1923 4 Sheets-Sheet 4 o u C u H Patented Sept. 16, 1924.

UNITED STATES PATENT OFFICE.

EDWARD C. SASNETT, OF \VASHINGTOIT, DISTRICT OF COLUMBIA.

AUTOMATIC TRAIN-CONTROLLING SYSTEM.

Application filed June 12, 1923. Serial No. 644,867.

correct signalling principles and which pro vides for minimum sate train spacing.

Continuous-indication systems, both conductive and inductive, have heretofore been proposed in a great variety of forms. The inductive type has been developed to a high degree, but so far as I am aware there has not been devised prior to my invention a usable system of the conductive, or third rail, type. The systems oi that type which have been proposed are either based on obviously unsound signalling principles or else they are absolute systems, that is, systems in which the assumption is made that a train on reaching a dead section and receiving a stop signal will stop until it gets a proceed indication. Absolute systems are of no practical utility, for the reason that a defect in the system would tie up trafiic indefinitely, whereas any practical train controlling system must of necessity provide for safe train movements under all conditions. 'The'present invention provides a system in which permissive train movements can occur even under danger conditions.

The main problem to be solved in devising a continuous-indication system of the third rail type is, to prevent a rear train when it comes into an occupied block from receiving the indication received by the forward train in that block. This can be done in three ways :-First, by providing a locking means :which'operates to lock the system of a train when it enters a block to the rear of an occupied block and which is unlocked only when a clear block is approached. Systems of this kind are known. They are really continuous indication systems under clear conditions only; under caution conditions they cannot respond to any change of traffic and therefore they' offer practically no advantage over a purely intermittent system. Second, by providing a run-down device which operates to lock the system only after the train has travelled under caution conditions through substantially the whole block, such run-down device being restored at the entrance of a clear block. In my 00- pending application, Serial Number 619076, filed Feb. 15, 1923, I have disclosed a system in which the problem is solved in this man ner. Third, by providing means to change the character of the signalling energy supplied to the third rail section. when a second train enters the occupied block pertaining thereto, and by constructing the train controlling means so that it is ineffective to give a clear indication when energized with current of this character following the entry of the train into an occupied block, but

effective to continue the clear indication when the change of energy occurs while the train is travelling under clear conditions.

The system of the present invention solves .the problem in the third way.

I will explain the specific nature, objects and advantages of my invention in the following detailed description in which reference will be had to the accompanying drawings, whereof Figs. 1, 2, 3 and 4 illustrate diagrammatically :tour systems which I have i nected to the rails at the entrance end of the section and a battery, or other source of energy, connected at the exit end. The

sections

10, 12 etc. are relatively short, or preliminary sections; and each block is composed of a preliminary section and a main section.

Arranged parallel with the track rails and supported in any suitable fashion is a conductor, or third rail, divided into sections 1+1, 15, 16 etc., which coincide with the block sections. So far as the present invention is concerned, this third rail may be supported between the track rails, at the side. thereof, or overhead.

At the entrance to each block section a pair of

relays

17, 18; 17', 18 etc. and a battery B, B, etc.

The vehicle equipment includes a contact shoe travelling on the third rail. a polarized relay 20 connected between the shoe and tion 11 with the block constituted by

sections

12 and 13 clear. Under these conditions, current from battery B" flows through the vehicle carried

relays

20 and 21 by the circuit shown in relatively heavy lines. It

will be noted that this circuit includes front contacts of

relays

13, 12', 18 and 10 and back contacts of relay 12. This circuit was formed by the passage of the vehicle through preliminary section 10 and entirely out of that section into section 12, by the sequential operations which will now be de scribed.

When the. first wheels and axle of the vehicle entered preliminary section 10, relay 10' opened its front contacts and closed its back contacts, thereby forming a pickup circuit for relay 17, which circuit is from battery B, conductor 29, back contact 30, front contact 31, relay 17 conductor 32 and through common conductor C to the battery. Relay 17 then picked up its armature, closing its front contacts, thereby closing a pick-up circuit for relay 18 from. batteryB, conductor 29, conductor 33, front contact 34, relay 18, conductor 32 and back to battery through the common conductor C. Relay 18, in turn, picked up its armature, closing its front contacts and opening its back contacts. When the vehicle entered section 11 and was partly in this section and partly in Section 10, relay 11 opened "its front contacts and closed its back contacts, opening the pick-up circuit of relay 17 at front contact 31. Relay 17 remained energized, however, through a circuit exclusive of front contact 31, this circuit including battery B, conductor 29, back contact 30, conductor 35, front contact 36, relay 1? etc. Then the vehicle entirely cleared section 10, relay 10 picked up, opening the retaining circuit of relay 17 just described at j back contact 30. Relay 17 thereupon opened its front contacts, opening the pickup circuit of relay 18 at front contact 34. Relay 18, however, did not drop its armature, since it was held energized by the following stick circuit: battery B, conductor 29, conductor 37, front/contact. 38, back contact 39, front contact 40, conductor 41,

relay 18, conductor back to battery through the common conductor C.

The circuit shown in heavy lines, therefore, which is formed when relays 13, 12,

18 and 10 are energized and relay 11 deenergized, was formed when the vehicle passed into section 11 and entirely out of section 10, with

sections

12 and 13 clear. Current flows in this circuit from battery B through the train carried relay 20 in a direction to hold the armature contact of this relay in engagement with the left hand. stationary contact, as shown in the drawing, thus connecting the slow acting neutral relay 21 across the wheels and travelling contact 19, in parallel with relay 20. Relay 21 is holding its front contacts closed and, since the circuits of magnet 24 and distant signal 28 include front contacts of this relay, magnet 24 is energized and distant signal 28 is held at clear. Magnet 24 i con nected with the worm shaft 23, which is continuously operated when the vehicle is in motion by a gearing which connects it with an undriven wheel of the vehicle, so that when magnet 24 is energized shaft 23 is held out of engagement with worm wheel 25, and the latter assumes its biased position, the position shown in the drawing; and, on the other hand, when magnet 24 is deenergized the worm shaft 23 drops into engagement with worm wheel 25 and drives the latter around slowly in exact proportion to the distance traveled by the vehicle.

Now suppose that with the vehicle in section 11 and with the wayside and vehicle circuits in the condition shown in the drawing, a second train should enter the block.

opening of front contact 38 opens the stick circuit of relay 18, which in turn opens its front contacts and closes its back contacts.

The closin of back contact 30 does not close the pick-up circuit of relay 17, be cause this circuit is now open at front contact 31, and relay 17 cannot close the pic-kup circuit of relay 18. WVhen the second train passes into section 11 and entirely out of section 10, the closing of front contact 38 does not reenergize relay 18, for thestick circuit of the latter is now open at front contact 40. Hence relay 18 is energized when a train passes into a clear block, but is deenei'gized when a second train enters the block and cannot be again energized until that block is clear.

When relay 18 dropped its contacts under the assumed conditions, the circuit shown in heavy lines was broken at the front contacts of said relay, but battery B was immediately connected across the third rail section 15 and track by connections including back contacts 42 of said relay and conductors 43. It will be observed that these connections reverse the direction of current through the vehicle circuit. This. reversal of current through the vehicle circuit already in the block causes armature of relay 20 to disengage its left hand contact and engage" its right hand contact. The disengagement of the left hand contact opened the connection of relay 21 with the wheels of the vehicle shown in heavy lines, but a connection to said wheels was immediately closed through the right hand contact of relay 20 and through front contact 43 of relay 21. Relay 21 should be of the slow pick up and slow release type and should be made sufliciently slow acting so that it will not open its contact while the armature of the polarized relay is passing from one of its stat-ionary contacts to the other, and will not kick off its armature by the reversal of current. For this purpose, the armature of relay 21. may be connected with a suitable dash pot, for example.

The entry of the second train into the block, therefore, does not affect the indications under which the first train is travelling. On this train the only change effected by the entry of the second vehicle is the reversal of polarized relay The second vehicle, on the other iand, does not get the clear indication under which the first train is travelling, as will be evident from the following considerations. When the second train entered the block to the rear of that constituted by

sections

10 and 11, it received no energy from battery B, since this battery was disconnected at

front contact

43 or 44, because of the presence. of the train in

section

10 or 11. Hence on the second train the armature of polarized relay 20 assumed a central. biased position, and relay 91 dropped its contacts. When, therefore, the second train entered section 10 with the first train in. section 11 and received current from battery B the contacts of its relay 21 were open, and since the direction of current from buttery B was reversed by the entry of said second train the relay 20 in the second train will throw its armature contact into engagement with the right hand stationary contact, but this will not connect the relay 21 of the second train with the third rail. and track, for the reason that the. connect-ion is open at front contact 43.

Assume now that when the train shown in section 11 entered the preliminary section 10 a vehicle was occupying either section 12 or 1.3. Under these conditions when the train entered section 10 it caused relay 18 to pick up by the connections already described, these connections being controlled solely by

track sections

10 and 11. The picking up of relay 18 connected battery B across the third rail and track through the front contacts 44 of relay 18, the back contacts of relay 10' and the front contacts 46 of relay 11. These connections impress battery B across the third rail and track with clear polarity, that is, with. the polarity which causes relay 20 to make contact with its left hand stationary contact. This connection is formed until the vehicle enters section 11, whereupon relay 11 drops and opens said connections at front contacts 46. When this happens current will no longer flow through the circuit of the rear vehicle, since the flow of current from battery B through the heavy line circuit is cut off by relay 19/ or 13, be cause of the presence of the vehicle in the block ahead. On the vehicle in section 11, therefore, the polarized relay 20 and the neutral relay 21 will be deenergized, causing distant signal 28 to assume caution position and causing the worm shaft 23 to engage the worm wheel 25. As the vehicle travels along section 11, the worm wheel will be rotated in he direction of the arrow in proportion to the travel of the vehicle. If at any time while the vehicle in section 11, the vehicle ahead should clear section 13, current would flow from battery B through said vehicle in section 11 by way of the neavy line circuit. This would cause relay 20 to throw its contact to the left and connect relay 21 across the third rail and track. The latter would accordingly pick up and cause the distant signal 28 to clear and the worm wheel 25 to assume its normal biased position. But if the train ahead does not clear section 13, when the vehicle in section 11 arrives at a point adjacent to the entrance of section 12, the worm wheel 25 would be rotated to the position where the cam 47 thereof passesout of engagement with circuit controller permitting it to open and interrupt the circuit of home signal 27, the latter assuming danger, or stop, position.

If after receiving a. danger indication, a vehicle should continue to travel and should enter the preliminary section of an occupied block, it would, as stated above, open the circuit of

relay

18, 18 etc, as the case may be, and the said relay could not be again energized until the block controlling it had been cleared. Suppose, for example, that a vehicle was travelling in the block preceding that of the occupied section 11, and suppose that after it had received a danger indication it had persisted and entered section 10. In this event relay 18 would be deenergized, reversing the current through the vehicle in section 1.1, but, as before pointed out, not affecting the indication under which this vehicle is travelling and not affecting the danger indication of the rear train. Relay 18 will remain deenergized as long as the rear vehicle is in section 11. Hence the rear vehicle could not get a clear indication even when the forward vehicle clears section 13, since the direction of current from battery B through the hack contacts 42 is such as to cause the polarized relay to throw its contact to right. and inasmuch as the neutral relay 21 of the rear vehicle is deenergized at this time, such closing of the right hand contact would. have no effect. This is a feature, however, wherein the present system falls short of theoretical perfection, since under these conditions the vehicle in section 11 should receive a clear indication. It cannot get a clear indication until it bridges section 12, thereby connecting battery 13 across the third rail and track through front contacts 4&1, back contacts 45 and front contacts 46. When these connections are made relay 20 will throw its contact to the left, connecting up relay 21 which clears distantsignal 21 and home signal 27. If now when the second train enters section 18 the block ahead is still occupied by the first train current will be cut off from the second train by the opening of front contacts 46'. The distant signal 28 of the sec- 0nd train will accordingly assume caution position and the worm wheel 25 will resume its rotation towards the position wherein it opens the circuit of home signal 27 From the foregoing description it will be understood that the present system provides for continuous indication of traffic conditions except where a second train has entered a block already occupied. In this event the second train cannot get a clear indication until it has traveled throughout the extent of the block, even though in the meantime the first train may have passed out of the block and cleared the block ahead. It is therefore desirable that a train should stop after receiving a danger indication, or for a reasonable time.

There is one other condition which may arise to prevent a train from receiving a clear indication when as a matter of fact the track ahead is clear. Assume the train in section 11 to be travelling under a caution indication, section 13 being occupied, and suppose that before section 13 is cleared a third train should enter section 10. The entry of the third train into section 10 would cause deenergization of relay 18, which would prevent the train in section 11 from getting a clear indication when sec tion 13 is cleared. It may be found preferable therefore to construct the worm wheel 25 so that when a train travelling under caution conditions arrives on a preliminary section 12 the home signal will assume stop position, and not before. However, the system is well adapted for continuous train movements, since it always effects a clear indication when a train passes onto the preliminary section of a clear block.

Attention is directed to the fact that the circuit shown in heavy lines is not formed until the vehicle entirely clears the preliminary section 10, said circuit including front contacts of this relay. When the vehicle is straddling

sections

10 and 11, it receives energy, if the block ahead is clear, through a circuit which is identical with the heavy line circuit except that this circuit includes back contacts, instead of front contacts, of relay 10. The flow of current through this circuit is the reverse of that through the heavy line circuit, being such as to cause relay 20 to throw its contact to the right. Therefore the current will always be reversed twice through the train when it enters each block under clear conditions, these reversals not affecting the clear indication.

The purpose of making the normal circuit, shown in heavy lines, through the front contacts of the preliminary relays is to insure that, in case of failure of a preliminary track relay, a second train entering an occupiedblcck will not receive a clear indication.

Fig. 2 shows a system very similar to that shown by Fig. 1. The track and way-- side circuits of the two systems are exactly the same; the vehicle equipments differ in severalparticulars. In Fig. 2, as in Fig. 1, a polarized relay 20 is connected on one side to the shoe 19, and on the other side to the wheels of the vehicle; and a neutral relay 21 is connected on one side to the wheels and on the other side to the arnniture contact of relay 20.

\Vhen relay 20 is energized with current of clear polarity, its armature contacts are held in the position illustri'ited, in which position relay '21 is connected with contact shoe 19 directly; when the polarity of current is reversed, relay 21 is connected to contact shoe 19 through a conductor 50, a circuit controller 51 and a conductor Circuit controller 51 .is held normally closed by a cam on a biased pivoted disk 53, and is permitted to open when this disk has been rotated through a predetermined angle. As in Fig. 1, disk 53 is adapted to be rotated by a worm shaft which is continuously rotating when thevehicle is in motion by a gearing which connects it to an undriven wheel of the vehicle. Normally wormshaft 54L is held out of engagement with disk 53 by a magnet which is under the control of a slow acting relay 56. As indicated in the drawing, disk 53 is mutilated, or has its gear teeth interrupted, at a point so located that after the disk has rotated through an angle sufficient to cause the circuit controllers to leave the cam on said disk, the

rotation of the disk will cease irrespective of the rotation of worm shaft 54. The home signal 27 in this system has two circuits, one of which is controlled by circuit controller 57 and the other of which is in parallel with the circuit of distant signal 28 and will be open when relay 21' is de energized. The home signal will be held in clear position so long as either of these circuits is closed.

The operation of this system is briefly as follows: The vehicle shown at the left of section 10 is travelling under clear conditions. Relay 20 is energized with clear polarity, connectingirelay 21' directly with the third rail and track. The circuit of distant signal 28 is closed at the front contact of relay 21, and the circuits of home signal 27 are closed at circuit controller 57 and at the front contact of relay 21. The circuit of magnet is closed at front contact 58 of slow acting relay 56, and the circuit of relay 56 is closed at contact 59 of polarized relay 20. In the. present system, as in the system of Fig. 1, when the vehicle shown at the left passes through section 10 and into section 11 current through the vehicle circuit is caused to reverse from clear and then to reverse back to clear when the vehicle entirely leaves section 10. These reversals cause relay 20 to throw its contacts from left to right and then from right to left, looking at the drawing. Vhen relay 20 throws its contacts to the right it disconnects relay 21' from shoe 19, but immediately reconnects it through the right hand stationary contact, conductor 50, circuit controller 51, and conductor 52. Relay 21 therefore is deenergized only momentarily, distant signal 21 remaining at clear. The pick-up circuit of relay 56 is also in terrupted at contact 59, but the holding circuit of this relay is immediately formed at contact 60, so that relay 56 does not drop, magnet 55 remaining energized. \Vhen current through relay 20 reverses back to clear, the circuit connections shown by the drawing are formed. as in the system of Fig. 1, the reversal of current through the vehicle relays of a vehicle entering a block under clear conditions cause no change of clear indication.

lVhcn a vehicle with this equipment enters a block under caution conditions and encounters a dead third rail section, relays 20 and 21 open their contacts. Distant signal 28 has its circuit interrupted at the front contactof relay 21 and assumes caution I position. Slow acting relay 56 has both its holding and stick circuits interrupted at contacts 59 and 60 respectively, and this relay accordingly opens its contacts, interrupting the circuit of magnet 55. \Vorm shaft 54 drops into engagement with disk 53 and drives this disk around in a counterclockwise direction proportionately to the travel of the vehicle.

After the vehicle has traveled under caution conditions through a predetermined portion of the block, the cam on disk 53. leaves cir:

cuit controller 57, permitting the same to open and interrupt the circuit of home signal 57, and since the other circuit of the home signal is now open at the front contact of relay 21 the home signal will assume danger position. The vehicle should In this system therefore,

now stop and await clearance of the block in advance. lVhen the block in advance is cleared current of clear polarity will flow through relay 20, causing

relays

21 and 56 to pick up and clear the home and distant signals. It will be noted from the drawing that circuit controller 51 is so located with reference to the cam on disk 53 that it will be opened subsequently to the opening of circuit controller 57. The parts are so designed that when the vehicle is travelling under caution conditions, circuit controller 51 will not be opened until the vehicle has travelled throughout substantially the extent of the block, while circuit controller 57 will be opened far enough in advance of the opening of circuit controller 51 to give ample time for the vehicle to be brought to a stop after receiving the stop signal consequent upon the opening of circuit controller 57.

If the vehicle under consideration should proceed after receiving a stop signal and enter the occupied block, it would cause reversal of the current through the vehicle relays of the vehicle already in the block, assuming of course that the vehicle already in the block is receiving a clear indication. Thisreversal of current through the vehicle already in the block would not change the clear indication under which that vehicle is travelling, as will be understood from the foregoing description. The reception of re- Verse current by the vehicle entering the block would not change its danger indication, since circuit controller 51 wasopened prior to the entry of said entry of said vehicle and since the reverse-current position of relay 20 is ineflective to energize slow acting relay 56.

In the system under consideration it is to be noted that a vehicle can always get a clear indication when the conditions are in fact clear, with one exception, viz, when it has entered an occupied section. That is to say, in this system a. vehicle can always receive a clear indication prior to the opening of circuit controller 51, which occurs just before the entry into an occupied section. In this respect the system of Fig. 2 has the advantage over the system of Fig. 1. It will be recalled that in the system of Fig. 1 when a second vehicle is travelling in a block under caution conditions and a third vehicle enters said block, the second vehicle cannot get a clear indication until it enters the preliminary section of a clear block. In the system of Fig. 2, under the same conditions, the second vehicle would have its magnet 21' energized as soon as the block ahead was cleared by means of the connections 50, 51 and 52, clearing home and distant signals.

Fig. 3 illustrates a third rail system by means of which a vehicle travelling under caution conditions may have its permissive 5 car 1 couplings.

speed controllednot only by the mere presence-of the vehicle in advance, but also by the speed thereof. In this system, as in the systems already described, the track is divid'ed into blocks, each of which is compowd of ashort :)

reliminary section

10, 12 etc., an'da

main section

11, 13 etc., each section forming part of a track circuit which includes a'

relay

10, 11, 12 etc. This system also includes wayside relays 17, 18; 17, 18' etc, which are controlled in substantially the same manner as the corresponding relays of the systems previously described. In fact the track and wayside circuits of this system are the same as those of Figs. 1 and 2, except that in Fig. 3, the energizing circuits ofrelays 17 and 18 etc. are controlled by the track relays of the block in advance, so that these relays cannot be energized un less the block in advance is clear. Also in this system the circuitfor clearing the train control mechanism when a train enters-the preliminary section of a clear block includes back contacts 45 and front contacts 46 but does not include front contacts of relay 16, as it does in the systems of Figs. 1 and 2.

The vehicle equipment of this system includes a polarized relay 20 and a slow actmg relay 21, which are connected and controlled in exactly the same manner as the corresponding relays of Fig. 1. Slow acting relay 21 controls the circuit of a magnet '24, which normally holds a vehicle driv-' en worm shaft 23 out of engagement with a biased pivoted disk 25, as in the system of Fig. 1. trols any suitable train control mechanism 61, which, so far as the present invention is concerned, may be of the distance-andspeed controlled type, the time-and-speed controlled type, or any other suitable type. In order to avoid complicating the drawings no signals are shown.

is adapted to be connected to contact shoe 1.9 and to the wheels of the vehicle through contacts which are closed only when the speed ot' the vehicle exceeds a predetermined value. In order to automatically interrupt the transmission of energy from generator 611 in thefievent that a car of the train breaks loose the connections of the generator are run through all the cars of the train by means of connectors 66 in the In this system each third $low acting relay 21 also con- The vehicle equipfment further lncludes a speed responsive rail section is adapted to be connected to the.

third rail section in rear thereof by the following connections: conductor 67, back contact 68, front contact 69, conductor 70, front contact 71, conductor 72, condenser 73, and conductor 74.

The system of Fig. 3 operates in the following manner: When the train (indicated by a pair of wheels and an axle) passes throu h section 10 and into section 11, relay 18 will pick up,

sections

12 and 13 being clear, and will remain up as long as the train occupies section 11, provided a second train does not in the meantime enter section 10, all of which will be understood fromthe foregoing description. Now if the train in section 11 is travelling above a predetermined speed, speed responsive arm 62 will connect contacts 65, thereby impressing the voltage of generator 6 f across the third rail and track. Let it be assumed that a second train similarly equipped is in the block to the rear of section 10. This second train will receive electrical energy from the first train through the

connections

67, 68, 69, 70, 71, 72, 73, 74, the third rail section, shoe 19 of the second train, conductor 75, relay 76, circuit controller 77, contacts 78, conductor 79 to the wheels and track rail back to the wheels and generator of the first train. Circuit controller 77 was closed shortly after the second train entered the block in rear of section 10 by the counter-clockwise rotation of disk 25 consequent upon the deenergization of relay21. This circuit controller is normally open but is closed by the cam on disk 25 following an initial operation of said disk. As long therefore as the speed" of the train in section 11 exceeds a predetermined value and the speed of the train in the section to the rear of section 10 is less than this predetermined value relay 76 on the latter train will be energized. Relay 76 when energized closes a shunt around the front contacts of relay 21, which are in the cir-' 'cuit of train control mechanism 61. Hence the train control mechanism of the rear train will be held out of action as long as the speeds of the two trains are within the predetermined limits. The speed above which a vehicle travelling under clear conditions will transmit energy and the speed below which a following vehicle will receive energy will be fixed to provide an ample factor of safety. Under all ordinary condi' tions, as long as the speed of the rear vehicle does not exceed that of the forward vehicle the train control mechanism of the rear vehicle may be held out of action with perfect safety. If the rear vehicle should enter section 10 while the forward vehicle is still in section 11, relay 18 would be deenergized and open contact 71, thereby pre-' venting the transmission of energy from either vehicle. Furthermore the disk 25 on the rear vehicle would" have rotated through an angle suilicient to cause opening of circuit controller 77, thus eliminating the possibility of the rear vehicle from receiving energy which might be transmitted from a vehicle in section 13'.

Fig. 4 illustrates a system in which the permissive speed of a train travelling under caution conditions may be controlled jointly by the speed of a train in an advance block and by the position thereof in said block. In this system the wayside circuits are exactly the same as in Fig. 3'. The vehicle equipmentincludes a polarized relay 20 permanently connected to the contact shoe 19 and'to the wheels of the vehicle, and a neutral relay connected to the wheels of the vehicle on one side and on the other side to the armature of relay 20. hen relay 20 is energized with clear polarity, relay 80 is connected to contact shoe 19 directly through the left hand contact of relay 20. When current through relay 20 is reversed, relay 80 is connected to contact shoe 19 through the right hand contact of relay 20 and circuit controller 81; and when relay 20 is deenergized relay 80 is disconnected. The vehicle equipment also comprises a shaft 82 driven by a wheel of the vehicle, a governor 83 driven by shaft 82, a worm wheel- 84 driven by a worm on shaft 82, a shaft 85 fixed to worm wheel 84,

gear wheels

86 and 87 fixed to shaft 85,. a shaft 88 having fixed thereon a gear wheel 89 and a cam 90, and a shaft 91 having fixed thereon a gear wheel 92 and a disk 93.

Shafts

88 and 91 are biased by weights, or other suitable means, to a definite position which they will assume when um'estrained. Gear wheel 89 is adapted to be driven by gear wheel 86 by means of an intermediate gear 94. As shown, gear 94 is ouirna-led in the upper end of a plunger of a solenoid 95. \Vhen solenoid 95 is energized gear 94 is raised into engagement with

gears

86 and 89, and shaft 88 and cam are driven in a clockwise direction proportionately to the travel of the train. \Vhensolenoid is deenergized, its plunger falls by gravity, releasing shaft 88 and permitting it to assume its biased position. Gear wheel 92 is adapted to be driven by gear wheel 87 through the medium of a gear 96 journaled in the end of a lever 97. Normally lever 97 is held by a magnet 98 with gear 96 out of engagement with gears 87 and 92. lVhen magnet 98 is deenergized a weight 99* on' the lever rotates it to bring gear 96 into engagement with gears 87 and 92. Shaft 91 is then driven proportionately to: the travel of the vehicle. When shaft 91 is released a weight 100 on disk 93 retates it to the position shown by the drawing. (lam 90' coacts with a roller 101 on a weighted lever which is pivoted at 102. The

upper end of this lever is connected by a link to an intermediate point on a floating lever 103. The lower end of lever 103 is jointed to a part which is moved by governor 83. The upper end of lever 103 is adapted to connect contacts 104 in the cir cnit of an alternating generator 105.

The system of Fig. 4 operates in about the following manner. The vehicle shown is travelling under clear conditions and has its relay 20 energized with current of clear polarity, the pivoted contacts of relay 20 being in engagement with the left hand stationary contacts. Relay 80 is directly connected to the contact shoe 19 and wheels of the vehicle through contact 105 and is holding its front contacts closed and its back contacts open. The speed of the vehicle and its position in the block are such that the contacts 104 are bridged by the floating lever 103. Accordingly the generator 105 is connected to the wheels and to the contact shoe 19 through front contacts of relay 80, the contacts 104 and through the connections 106 which pass through all the cars of the train. Magnet 95 is energized by battery 107 through connections which include the contact 108 of relay 20. The cam 90 is accordingly being rotated in a clockwise direction. Magnet 98 is energized from battery 107 through connections which include a front contact of relay 80, and is holding gear wheel 96 out of mesh with gears 87 and 92. Disk 93 is therefore in its normal; biased position. The circuit of a suitable train control mechanism is closed at front contacts of relay 80-, so that said mechanism is held from operation. When the vehicle passes through section 10 and into section 11, with section 13 clear, the current through relay 20 will be reversed from clear. The direct connection of magnet 80 will be interrupted, but said magnet will be immedi ately connected again with shoe 19 through the right hand contact of relay 20 and the circuit controller 81, so that said magnet will not be deenergized for any appreciable time. Solenoid 95 will be deenergized by the interruption of its circuit at contact 108, permitting gear wheel 94 to fall out of mesh with the

gears

86 and 89. The biased shaft 88 and cam 90 will accordingly rotate to an initial position in a counterclockwise direction which will permit the weighted lever to rotate also in a counterclockwise direction to its initial position. When the vehicle has entirely cleared section 10 the current will again reverse to clear, which will cause relay 20 to connect relay 80 directly with contact shoe 19 and also to close the circuit of solenoid 95 at contact 108. Magnet 95 will raise its plunger to engage gear 94 with

gears

86 and 89, and cam 90 will resume its rotation in a clockwise direction from its initial position. Thus each time the vehicle travelling under clear conditions enters a block gear 89 is released and cam 90 assmnes the initial position to which it is biased and when the vehicle clears the preliminary section of the block, cam 90 will again be driven around in a clockwise direction. If while the vehicle is traveling in section 11 under clear conditions, a second vehicle should enter the block in rear, the second vehicle would re ceive alternating energy from the vehicle in section 11, provided the position and speed of the first vehicle were such as to cause the floating'lever 103 to bridge the contacts 104. Assuming that this is the case, the second vehicle would receive energy through the

connections

67, 68, 69, 71, 72, 73, the contact shoe 19 of the second vehicle, back contact 110 of relay 80, relay 111, circuit controller 112, back contact113 of relay 80, to the wheels and track and back to the generator of the first train. Relay 111 would accordingly be energized and close a circuit of train control mechanism 109, to hold this mechanism from operation, permitting the second tra n to proceed at full speed. If desired, of course, the circuit of relay 111 could be controlled by the governor 83 so as to limit the permissive speed of the vehicle when it enters a block preceding an occupied block. The cam 90 as it rotates from initial position gradually lowers the speed at which governor 83 holds lever 103 in engagement with contacts 104:, these contacts being bridged only at high speed when the vehicle is in the entrance portion of a block, while they are bridged at both high and low speeds when the vehicle is adjacent the exit end of a block, the bridging speed, that is the speed at which the contacts are just on the point of being opened, continuously decreasing from the entrance to the exit end of the block. It will be understood that as the cam 90 rotates from its initial position it gradually moves the joint between lever 108 and the link connected to the upper end of the weighted lever towards the right, looking at the drawing, and therefore tends to move the upper end of lever 103 to the right- Since thegoverno'r 83 tends to move the upper end of lever 103 towards the left as the speed of the vehicle decreases, it follows that the vehicle may proceed at a gradually decreasing speed through the block without moving the upper end of lever 103 away from the left hand ends of contact segments 10%, it being understood that the parts are so constructed that at all higher speeds than this gradually decreasing speed limit the contacts are bridged by the upper end of lever 103. In short, the cam 90 establishes a gradually decreasing speed curve, below which the contacts 104 are opened and above which they are closed.

In this system, as in the system of Fig. 3, if a vehicle should enter an occupied block, the transmission of vehicle energy is cut out at contact 71, and the reception of vehicle energy by the rear vehicle is cut out by reason of the opening of circuit control.- ler 112.

lVhile all of the systems illustrated are of the polarized type, it will be understood those skilled in the art that the principles of the invention can be embodied in systen'is utilizing currents of different strength or currents of different character, such as two alternating currents of different frequencies. It will be also understood by those skilled in the art that the system of this invention can be applied to electrically operated vehicles, and by known expedients the third rail for supplying pro pulsion current to such vehicles can also be used to supply the signalling energy.

I claim:

1. In a continuous indication train controlling system, a track divided into block sections, a vehicle traveling on said track and provided with governing mechanism and with an electro-responsive device controlling said mechanism, means for continuously supplying normalelectrical energy to said electro-responsive device during the travel of thevehicle along the track under clear tl'tlillC conditions and for discontinuing the supply of said energy under caution conditions, means for supplying said electroresponsive device with abnormal energy when the vehicle entersv an occupied block, and means for preventing said electro-responsive device from controlling said governing mechanism when supplied with said abnormal energy following the entry of the vehicle into an occupied block.

2. I11 a continuous indication train controlling system, a track divided. into block sections, a vehicle travelling onsaid track and provided with governing mechanism and with an electro-responsive device controlling said mechanism, means for continuously supplying normal electrical energy to said electro-responsive device during the travel of the vehicle under clear trafiic conditions and for discontinuing the supply of said energy under caution conditions, means for supplying said electro-responsive device with abnormal energy when two or more vehicles occupy the same block, and means to prevent said electro-responsive device from controlling said governing mechanism when energized with said abnormal energy following the entry of the vehicle into an occupied block and to continue the control over said governing mechanism by said elec tro-responsive device when the change from normal to abnormal energy occurs while the vehicle is travelling under clear conditions.

3. In a continuous indication train controlling system, a track divided into block sections, a vehicle travelling on said track provided with governingmechanism and with. an electro-responsive device controlling said mechanism, means for contin uously supplying normal electrical energy to said device during the travel of the ve hicle under clear conditions, means for supplying said device with abnormal energy when two or more vehicles occupy the same block and the block in advance is clear, and means operating to prevent said electro-responsive device from controlling said governing mechanism when energized with abnormal energy following the entry of the vehicle into an occupied block but to continue the control over said governing mechanism by said electro-responsive device when the change from normal to abnormal energy occurs while the vehicle is travelling under clear conditions.

4. In a continuous indication train controlling system, a track divided into block sections, a conductor parallel to said track, avehicle travelling on said track having a contact engaging said conductor, an electro-responsive device connected to said contact, train controlling means governed by said electro-responsive device, means for supplying normal energy to said conductor under clear trafiic conditions and for effecting a changein the energy supplied to said conductor when two or more trains occupy the block pertaining to said conductor, said electro-responsive device being ineffective to clear said train controlling means when energized with said changed energy following the entry of the vehicle into an occupied block and being effective to hold said train controlling means clear when the change of energy occurs while the vehicle is travelling under clear conditions.

. 5.,In a continuous indication train controlling system. a track divided into block sections, a conductor parallel to the track divided into corresponding sections, a vehicle travelling on said track having a contact engaging said conductor, an electroresponsive device connected to said contact,

.vehicle controlling means governed by said electro-responsive device, means for supplying normal energy to a conductor section when the vehicle is travelling in the block pertaining to said section and for effecting a change in the energy supplied to said section whena-second vehicle enters the block, said electro-responsive device being inefi'ective to clear said vehicle controlling means when energized with said changed energy following the entry of the vehicle into an occupied block and being effective to hold said vehicle controlling means clear when the change of energy occurs while the vehicleis travelling under clear conditions.

6. In a continuous indication train controlling system, a track divided into block sections, a conductor parallel to the track divided into corresponding sections, vehicles travelling on said track having contacts e11- gaging said conductor and having electroresponsive devices connected to said contacts and vehicle controlling means governed by said electro-responsive devices, means for supplying normal energy to a conductor section when a vehicle is in the block pertaining thereto and traffic conditions are clear and for effecting a change in the energy supplied to said section when a second vehicle enters the block, and means for preventing the electro-responsive device on the second vehicle from clearing its vehicle controlling means.

7. In a continuous indication train controlling system, a track divided into block sections each consisting of a short preliminary section and a main section, a closed track circuit including a track relay for each section, a third rail parallel to the track divided into block sections corresponding to the track sections, an ,electro-responsive device for each block section, an energizing circuit for each device controlled by the track relays of the respective block, a retaining circuit for each device including a front contact of the respective preliminary track relay, a back contact of the main track relay and a contact which is closed only when the device is energized, means controlled by said electro-responsive devices for energizing the respective third rail sections with one character of energy when said devices are energized and with a different character of energy when said devices are deenergized, vehicles travelling on said track having contacts engaging said third rail and having electro-responsive devices connected to said contacts and vehicle controlling means governed by said electro-responsive devices and held at clear when said devices are energized, said electro-responsive devices after having been deenergized being ineffective to clear said vehicle controlling means when energized with said energy of different character.

8. In a continuous indication train controlling system, a track divided into block sections each consisting of a short preliminary section and a main section, a closed track circuit including a track relay' for each section, a third rail parallel to the track divided into block sections corresponding to the track sections, an electro-responsive device for each block section, an energizing circuit for each device controlled by the track relays of. the respective block, a retaining circuit for each deviceincluding a front contactof the respective preliminary track relay, a back contact of the main track relay and a contact which is closed only when the device is energized, means controlled by said electro-responsive devices for energizing the respective third rail sections with normal energy when said devices are energized and for effecting a change in the energy supplied to said third rail sections when said devices are deenergized, vehicles travelling on said track having con tacts engaging said third rail and having electro-responsive devices connected to said contacts andv vehicle controlling means gov erned by said electron'esponsive devices, and slow acting electro-responsive means governed by said electro-responsive devices for preventing clearance of said vehicle controlling means when the vehicle enters an occupied block.

9. In a continuous indication train controlling system, a track divided into block sections, a vehicle travelling on said track and provided with an electro-responsive device, means for continuously supplying normal electrical energy to said electro-responsive device during the travel of the vehicle along the track under clear traffic conditions andv for discontinuing the supply of said energy under caution conditions, means for supplying said electro-responsive device with abnormal energy when the vehicle enters an occupied block, a slow acting relay having a pick up circuit closed by said electroresponsive device when the latter is energized with normal energy and having a stick circuit closed by said electro-r-esponsive de vice when the latter is energized with abnormal energy, and vehicle controlling means controlled by said slow acting relay.

10. In a continuous indication train controlling system, a track divided into block sections, a conductor parallel to the track divided into corresponding sections, a vehicle travelling on said track having a contact engaging said conductor and having an electroresponsive device connected to said contact, means for supplying normal energy to a conductor section when the vehicle is travelling in the block pertaining to said section and foreflecting a change in the energy supplied to said section when a second vehicle enters the block, a slow acting relay having a pick-up circuit closed by said electroresponsive devicewhen the latter is energize'd with normal energy and having a stick circuit closed when said electro-responsive device is-energized by said changed energy, and vehicle controlling means governed by said relay.

11. In a continuous indication train controlling system, a track divided into block sections, a conductor parallelto the track divided into corresponding sections, a vehicle travelling on said track having a contact engaging said conductor and having an electro-responsive device connected to said contactymeans for supplying normal energy to a conductor section when the vehicle is travelling in the block pertaining to said section and the block inadvance is, clear,

said meansbeing under the control of a vehicle approaching from the rear and operating to disconnect the normal energy and supply said section with abnormal energy when a rear vehicle enters said occupied block, a slow acting relay having a pick-up circuit which is closed by said electro-responsive device when the latter is energized with normal energy and having a stick circuit which is closed when said electro-responsive device is energized with abnormal energy, and vehicle controlling means governed by said relay.

12. In a continuous indication train controlling system,-a track, a vehicle travelling on said track and provided with governing mechanism and with an electro-responsive device controlling said mechanism,.means for continuously supplying normal electrical energy to said electro-responsive device during the travel of the vehicle along'the track under clear trafiic conditions and for discontinuing the supply of said energy under caution conditions. said means being con trolled by a vehicle approaching from the rear and operating to discontinue the supply of normal energy and supply, abnormal e11- ergy to said electro-responsive device when the rear vehicle approaches said vehicle, said abnormal energy being ineffective to change the indication on the forward vehicle when the latter is travelling under clear conditions at the time thechange from normal to abnormal energy occurs. i

13. In a continuous indication train con trolling system,a track, vehicles travelling on saidtrack and each provided with governing mechanism and with an 'electro-responsive device controllingsaid mechanism, means for continuously supplying normal electrical energy to said electro-responsive device during the travel of the vehicles along the track under clear trafiic conditions and for discontinuing the supply of said energy under caution conditions, said means being controlled by a vehicle approaching from the rear and operating to discontinue the supply of normal energy and to supply abnormal energy when a rear vehicle travelling undercaution conditions approaches within a predetermined zone of the forward vehicle which is travelling under clear conditions, said abnormal energy being ineffective to change the indication on the forward vehicle and being ineffective to give a clear indication on the rear vehicle.

14. In a continuous indication train con trolling system, a track, vehicles travelling on said track, means for establishing a circuit between two adjacent vehicles, a switch on the forward vehicle controlled-by the speed thereof adapted to open said circuit when the vehicle is travelling below a predetermined speed and to close said circuit when the vehicle is travelling above sald predetermined speed, and an electroresponsive device on the rear vehicle in said circuit controlling said rear vehicle.

, 15. In a vehicle controlling system, a track, vehicles travelling on said track, means for establishing a circuit between two adjacent vehicles, a switch on the forward vehicle controlled by the speed thereof adapted to open said circuit when the vehicle is travelling below a predetermined speed and to close said circuit when the ve hicle is travelling above said predetermined speed, an electro-rcsponsive device on the rear vehicle in said circuit controlling said rear vehicle, and means for interrupting said circuit when the rear vehicle approaches within a predetermined Zone of the forward vehicle.

16. In a vehicle controlling system, a track, vehicles travellin on said track, means for establishing a circuit between two adjacent vehicles, a switch on the forward vehicle in said circuit controlled by the speed of said forward vehicle and by its position with respect to the track, and an electro-responsive device on the rear vehicle in said circuit controlling said rear vehicle.

17. In a vehicle controlling system, a track, vehicles travelling on said track, means for establishing a circuit between two adjacent vehicles, a switch on the forward vehicle in said circuit controlled; by the speed of said forward vehicle and by its position with respect to the track, an electro responsive device on the rear vehicle in said circuit controlling said rear vehicle, and means for interrupting said circuit when the rear vehicle approaches within a predetermined zone of the forward vehicle.

18. In a vehicle controlling system, a track divided into block sections, vehicles travelling on said track, means for establishing a circuit between two vehicles in adjoining blocks, a speed responsive switch on the forward vehicle controlling said circuit, an electroresponsive device on the rear vehicle in said circuit controlling said rear vehicle, and means for automatically interrupting said circuit when the two vehicles occupy the sameblock.

19. In a continuous indication train con trolling system, a-track divided into block sections having track relays in closed track circuits, a third rail divided into corresponding sections, vehicles travelling on said track, means controlled by the track relays and including said third rail for establishing a circuit between two vehicles when they occupy adjoining blocks, means on the for ward vehicle responsive to the speed thereof for controlling said circuit and an electroresponsive device in said circuit on the rear vehicle controlling the latter.

' 20. In a vehicle controlling system, a track divided into block sections having track relays in closed track circuits, a third rail divided into corresponding sections, vehicles travelling on said track, means controlled by the track relays and including said third rail for establishinga circuit between two vehicles when they occupy adjoining blocks, means on the forward vehicle responsive to the speed and position thereof in the block for controlling said circuit, and an electro-responsive device on the rear vehicle controlling the latter.

21.111 a vehicle controlling system, a track divided into block sections having track relays in closed track circuits, a third rail dividedinto corresponding sections, vehicles travelling on said track, means controlled by the track relays and including said third rail for establishing a circuit between two vehicles in adjoining blocks, a switch on the forward vehicle in said circuit controlled by the speed thereof, an electro-responsive device on the rear vehicle in said circuit controlling said rear vehicle, and automatic means for interrupting said circuit when the rear vehicle enters the block occupied by the forward vehicle.

22, In a vehicle controlling system, a track divided into block sections having track relays in closed track circuits, a third rail divided into corresponding sections, vehicles travelling on said track, means controlled by the track relays and including said third rail for establishing a circuit between two vehicles when they occupy adjoining blocks, means on the forward vehicle responsive to the speed and position thereof in the block for controlling said circuit, automatic means for interrupting said circuit when the two vehicles occupy the same block, and an electro-responsivc device on the rear vehicle in said circuit controlling said rear vehicle.

23. In a vehicle controlling system, a track divided into block sections, each con-- sisting of a short preliminary section and a main section, a closed track circuit including a track relay for each section, a third rail parallel to the track divided into block sections corresponding to the track sections, an e-lectro-responsive device for each block section, an energizing circuit for each device controlled by the track relays of the respective block, a retaining circuit for each device including a front contact of the respective preliminary track relay, a back contact of the main track relay and a contact which is closed only when the device is energized, means controlled by the electro-responsive devices for connecting the respective third rail sections of the blocks pertaining thereto to the preceding third rail sections, vehicles having contacts engaging said third rail. and a circuit between two vehicles in adjoining blocks, said circuit including a speed responsive switch and a source of energy on the forward vehicle, the third rail sections of the two blocks and a vehicle controlling electro-responsive device on the rear vehicle.

24. In a continous indication train controlling system, a track divided into block sections each consisting of a short preliminary section and a main section, a closed track circuit including a track relay for each section, a third rail parallel to the track divided into block sections correspondingto the track sections, an electro-responsive device for each block section, an energizing circuit for each device controlled by the track relays of the respective block, a retaining circuit for each device including a front contact of the respective preliminary track relay, a back contact of the main track relay and a contact which is closed only when the device is energized, means controlled by said electro-responsive devices for energizing the respective third rail sections with normal signalling energy when said devices are energized and for changing the signalling energy when said devices are decnergized, vehicles travelling on said track having contacts engaging said third rail and having translating devices connected to said contacts and vehicle controlling means governed by said translating devices, slow acting means on each vehicle governed by the translating devices thereof for preventing clearance of a vehicle controlling means when the vehicle enters an occupied block, means including the third rail sections for establishing a circuit between two .vehicles in adjacent blocks, said circuit including a front contact of the electro-responsive device associated with the forward block, a circuit controller on the forward vehicle in said circuit, an elcctro-responsive device on the rear vehicle in said circuit, and a source of energy in said circuit on the forward ve hicle of a different character from said signalling energy and ineffective to actuate said translating devices.

25. A continuous indication train controlling system comprising a track divided into block sections, aconductor parallel to the track divided into corresponding sections, a vehicle travelling on said track having a contact engaging said conductor, a translating device connected to said contact, vehicle controlling means governed by said translating device, means for supplying normal signalling energy to a conductor section when a vehicle is travelling in the the block pertaining to said section and for changing the siginalling energy when a second vehicle enters the block, said translating device being ineffective to clear said vehicle controlling means when energized with said changed energy following the entry of the vehicle into an occupied block and being effective to hold said vehicle controlling means clear when the Change of energy occurs while the vehicle is travelling under clear conditions, means including the respective conductor sections for establishing a circuit between two vehicles in adjacent blocks, a source of energy in said circuit on the forward vehicle of a different character from said signalling energy and ineffective to energize said translating devices, a speed responsive switch on the forward vehicle in said circuit, and a translating device on the rear vehicle in said circuit controlling the vehicle controlling meansthereof.

26.' A train controlling system comprising a track and vehicles travelling thereon, train controlling devices on said vehicles, means for governingsaid devices automatically in accordance with trafiic conditions, and additional means for governing the train controlling devices of a following vehicle in accordance with the speed of the vehicle immediately in advance thereof.

27. A train "controlling system comprising a track and vehicles,travelling there0n,train controlling devices on saidvehicles means for governing said devices automatica'llyin accordance with traiiic conditions, and additional means for governing the train controlling devices of a following vehicle in accordance with the speed and position of the vehicle immediately in advance thereof.

28. A train controlling system comprising a track and vehicles travelling thereon, controlling devices on said vehicles, trafiic controlled means for supplying signalling energy to said devices from the track, means for establishing a circuit between two ad'- jacent vehicles, a speed-responsive switch and a source of energy of a dilferent' character from said signalling energy on the forward. vehicle in said circuit, and an electro-responsive device on the rear vehicle in saidcircuit governing said controlling devices.

29. A train controlling system comprising a track and vehicles travelling thereon, controlling devices on said vehicles, means for continuously supplying signalling energy from the track to saidvehicles when travelling under clear traffic conditions and for discontinuing the supply of energy to a rear vehicle when it approaches within a predetermined zone of a vehicle in advance, means for establishing a circuit between the two vehicles when the'rear vehicle enterssaid zone, an electro-responsive device on the rear vehicle in said circuit, and a source of energy on the forwardvehicle-in said circuit of a different character from said signalling energy.

3-0,. A train controlling system comprising a track and vehicles travelling thereon, controlling devices on the vehicles, means for co ntinuously supplying signalling energy rrom the track to said devices when the vehicles are travelling under clear traffic conditions, means for establishinga circuit between two adjacent vehicles, an electro-responsive device in said circuit on the rear vehicle governing the controlling devices thereof, a source of energy on the forward velricle of a different character from said signalling energy in said circuit, and means for controlling said circuit in accordance with the speed of the forward vehicle.

31. A train controlling system comprising a track divided into block sections and vehicles travelling thereon, controlling devices on the vehicles, means for continuously supplying signalling energy from the track to said devices when the vehicles are travelling under clear traffic conditions, means for establishing a circuit between two vehicles in adjoining blocks, an electro-responsive device on the rear vehicle governing the controlling devices thereof, a source of energy on the forward vehicle of a different character from said signalling energy in said circuit, and means for controlling said circuit in accordance with the speed of the forward vehicle and its position in the block.

82. In a vehicle controlling system, a track divided into block sections, each con sisting of a short preliminary section and a main section, a closed track circuit including a relay for each section, an electro-responsive device for each block section, an energizing circuit for each device controlled by the track relays of the respective block, a retaining circuit for each device including a front contact of the respective preliminary track relay, a back contact of the main track relay and a contact which is closed only when the device is energized, vehicles travelling on said track having controlling devices, means controlled'by said electroresponsive devices for supplying signalling energy from the track to said train controlling devices when the vehicles are travelling under clear traffic conditions, means including front contacts of the respective electroresponsive devices for establishing a circuit between two vehicles in adjoining blocks, an electro-responsive device in said circuit on the rear vehicle governing the controlling devices thereof, a source of energy on the forward vehicle of a different character from said signalling energy in said circuit, and means for controlling said circuit from said forward vehicle.

33. A train controlling system comprising a track and vehicles travelling thereon, controlling devices on said vehicles, means for continuously supplying signalling energy to said devices under clear trailic conditions and for discontinuing the supply of energy to a rear vehicle when it approaches within a predetermined zone of a vehicle in advance, an electro-responsive device on the rear vehicle governing said controlling devices, and a source of energy and a switch on the forward vehicle governing said electro-responsive device, said source of energy being of a different character from said signalling energy.

34-. A train controlling system comprising a track and vehicles travelling thereon, controlling devices on said vehicles, means for supplying signalling energy to said devices under clear trafiic conditions, an electro-responsive device on the rear vehicle governing said controlling devices, and a source of energy of a different character from said signalling energy and a speed responsive switch on the forward vehicle governing said electro-responsive device.

35. A train controlling system comprising a track divided into block sections and vehicles travelling thereon, controlling devices on the vehicles, means for supplying signalling energy from the track to said devices under clear traffic conditions, an electroresponsive device on the rear vehicle governing the controlling devices thereof, a source of energy on the forward vehicle of a different character from said signalling energy, and means for controlling said electroresponsive device from said source of energy in accordance with the speed of the forward vehicle and its position in the block.

36. In a vehicle controlling system, a track divided into block sections, each consisting of a short preliminary section and a main section, a closed track circuit including a relay for each section, an electro-responsive device for each block section, an energizing circuit for each device controlled by the track relays for the respective block, a retaining circuit for each device including a front contact of the respective preliminary track relay, a back contact of the main track relay and a contact which is closed only when the device is energized, vehicles travelling on said track having controlling devices, means controlled by said electroresponsive devices for supplying signalling energy from the track to said train controlling devices, and means controlled by the respective electro-responsive device for governing a rear vehicle in accordance with the speed of the vehicle in the block immediately in advance thereof.

In testimony whereof I hereunto aflix my signature.

EDWARD C. SASNETT.