US2223131A - Coded continuous inductive train control and cab signaling system for railroads - Google Patents

Description

NOV. 26, W H REICHARD HAL L AND CAB CODED CONTINUOUS INDUCTIVE TRAIN CONTRO SIGNALING SYSTEM FOR RAILROADS Filed Aug. 30, 1939 5 Sheets-Sheet l I INVENTORS WHReichard and C5 Bushnell Mb MMM THEIRATTORNEY w. H. REKZHARD ETAL 3% CODED CONTINUOUS INDUCTIVE TRAIN CONTROL AND CAB SIGNALING SYSTEM FOR RAILROADS Filed Aug. 30, 1939 5 Sheets-Sheet 3 UA E ll 4/ e Saw Y M MMR m a o V a A 5 Sheets-Sheet 4 INVENTORS W. H Pe'|cha.rd and CSBushneH THEIR ATTORNEY .W. H. REHCHARD ETAL 000m) com muous INDUCTIVE TRAIN common AND CAB SIGNALING SYSTEM FOR RAILROADS Filed Aug :50, 1939 mm fin Nov. 26, 1940. RElcHARD ETAL 2,223,131

CODED CONT INUOUS 'INDUCTIVH TRAIN CONTROL AND CAB SIGNALING SYSTEM FOR HAILROADS Filed Aug. 50, 1939 5 Sheets-Sheet 5 Release PosiTion Reducfion Ll'miTing Reservoir Equali gr'ng Res 2 rvo I'r INVENTORS W dReichard and CSBushneH MMWW THEIR ATTORNEY Patented Nov. 26, 1940 PATENT. OFFICE CODED CONTINUOUS INDUCTIVE TRAIN CONTROL AND CAB SIGNALING SYSTEM FQR RAILROADS Wade H. Reichard and Charles S. Bushnell, Rochester, N. Y., assignors to General Railway Signal Company, Rochester, N. Y.

Application August 30|, 1939, Serial N0. 292,628

, 20 Claims.

This invention relates, in general, to train control'systems, and has more particular reference to systems of the coded continuous inductive type, including cab signals and speed control.

One of the objects of the present invention is to provide new and improved suppressive braking means whereby, upon the actual speed exceeding a newly imposed, reduced, limiting speed,

I, a reasonable time is provided for the engineer to apply his brakes and move his master controller handle to the off position, in order to thereby forestall an emergency brake application.

Another feature of the present invention is to provide a new and improved pneumatically operated propulsion current cut-out relay.

Another feature of the present invention is to so arrange and circuit the decoding relays employed in the system, as to, in general, make the system quick and sensitive to respond to changes from less to more restrictive conditions,-and slow, and less sensitive to respond to changes from more to less restrictive-conditions.

Another feature of this invention is to provide means for giving adequate, and arresting, visual and audible indications when the speed limit is being closely approached.

A further object of the invention is to provide improved acknowledging and non-signaled territory controls.

Further objects, purposes and characteristic features of the invention will appear as the description progresses, reference being made to the accompanying drawings, showing, in a wholly diagrammatic manner, and in no sense, whatso- 5- ever, in a restrictive way, one form which the invention can assume. In the drawings:

Fig. 1 of the drawings is a diagrammatic representation of one form of the invention and is comprised of the partial Figures 1A, 1B, 1C and 11) assembled with the lower long edge 'of 1A matching the upper'long edge of 1B and the right and the left short edges of 1C and 1D respectively matching the left and right short edges of 13.

' Fig. 2 shows the engineers brake valve in one of its operative positions. I

Referring now to the drawings, there is here shown in a schematic manner, a car equipped with apparatus in accordance with this invention. Each car has a cab at each of its ends, as cab A, and cab B, and is capable of running with either end forward. Much of the apparatus involvedin the present invention is includedin the designated Mech. Case and Gov,, which can be conveniently located, is common to the two cabs, and is employed in connection with each of the cabs.

The equipment peculiar to each cab, is identical in thecase of each cab,vand accordingly, a description of the equipment in one cab, should 5 largely suflice for the other cab.

Before considering any of the operation of the system in any considerable detail, it would ape pear in the interest of clarity, to briefly describe the apparatus peculiar to a cab.

Referring now to cab A, shown as Cut in, as the forward cab, there is here provided an acknowledging 'contactor Ack. 'C., which is operable by the engineer by means of a foot pedal; a non-signal contactor N. S, C., which is relatively inaccessible to the engineer, being positioned in the roof of the car outside of the cab door, and operable by the handle of theengineers brake valve; and a directional switch, Direc. Sw., which is conveniently located-for operation by its own handle. The functions performed by these three contactors will appear as the description progresses.

In addition to the above, there is provided in each cab, an engineers brake valve EBV, which, in the present case, is of the M-24-D type,.the' feed valve in the branch pipe 65 omitted; and (with the handle latch means, whereby the handle can be removed only when in the handle off position, and then only if a full service brake application has been incurred, also omitted) this valve is provided withla special adapter E, involved in the operation. of a suppression relay SR. Also, in each cab is a master controller MC, an electro-pneumatic valve EPV, a power-off relay FOR, an emergency cut-out valve ECV, an emergency application valve EAV, and a brake pipe'cut-out valve BPCV.

Considering the above devices somewhat more in detail, the brake pipe cut-out valve BPCV' can be positioned in either of its two indicated positions, in and out. In cab A this valve is shown in its in position, wherein the engineers brake valve EBV is connected to the brake pipe BP, by means of the port 2, the power-off relay POR is connected, by means of pipe 3 to the valve port 4, and thence by means of pipe 5, and the port 6 of the emergency'cut-out valve ECV, in its in position, to the passage 1 in EPV; This passage I, with'EPV in its energized position, as shown, communicates with a chamber 8, connected, through passage 9 and pipe l0, check valve ll, strainer l2, and pipe l3, to the brake pipe BP. Thus, brake pipe air pressure is con- 25 v stantly keep his hand on" the handle, as otherpipe cut-out valve BPCV is here in its out position, wherein it can be seen that the engineers brake valve is blanked off from the brake pipe by means of the portion 15 ofthe cut-out valve. Also in this case, thepipe I6 connected to atmosphere, is connected through the cut-out valve and pipe H to the power-off relay POR Returning to cab A, the master'controllerMC,

controls energy for forward operation of the car,

which is electrically propelled. ,It includes a handle l8, shown in its off position, wherein, by means of a key IS in its oil? position, the-handle is held down against the urge of a spring 20, which otherwise would unseat a valve 2|, and connect pipe It, to atmosphere, through a vent 22. When the key is in any other than the off .0; l ingcontact strips the port 3| leading to atmosphere, and intercom position, it is necessary that the engineer conwise the above referred to venting will automatically take place, and; as described below, will result in an emergency brake application. The handle rotates a contact'carrying drum 23, hav 24 and 25, for purposes to be later described; v I 7 The electro-pneumatic valve EPV is of usual construction, and functions as, for example, in the patent to C: F. Estwick, No. 1,704,183, granted March 5,1929: In general it comprises a casing 26, containing a winding 21, which, when enere gized, overcomes the influences of springs 28 and 29, and maintains valve 30 in the position as shown in cab A, that is, in a position to blank off nect passages 7 and 9 by way of the chamber8.

When the EPV is deenergized, as is the case with EPV of cab B, valve 30 is moved to its upper position, whereby to connect passage 1 to atmosphere, and blank'ofi' the passage 9 from communication with passage 1 Thesuppression relay SR comprises a casing 32, enclosing-a fixed contact 33, and a movable 5 contact 34, which are biased toward open position engineers brake valve EBV.

' cab which is cut in,

"by aspring 35, operating through an arm 36. It

is possible to overcome the eiTect. of spring 35, by meansof a pneumatically operating diaphragm 3?, controlled by air pressure .in a chamber 38, connected by pipe 33, to the adapter E of the The emergency cut-out valve ECV can be moved to either of its two positions in or out, and in cab A, and as well in cab B, it is shown in its in" position, wherein air pressure in the brake pipe is When moved to its out position, the EPV is cut out of service, and is incapable of effecting any control on the brake system. This emergency cut-out valve is sealed, and is not intended to be operated except under emergency conditions.

The emergency application valve EAV, comprises a casingf ifi, havinga chamber 4|, and another chamber 42, and interconnected valve 43 and piston44, together with a biasing spring 45. With the emergency application valve in ,a as is cab A, brake pipe pressure exists in chambers 42 and 4|, and due to the excess area of valve 44, over valve 43, and

. the spring, 45, 'valve 43 is maintained on its seat so as to disconnect the brake pipe 46 from atmos-.

phere through valve passage 41;

The power-off relay POR, comprises a cover 48, in which are fixed contacts 49, which coact with movable contacts 50, carried on a stem 5|, to which is connected a piston 52, operating in a cylinder 53. Thiscylinderw53is in --communication with pipe 3, and the piston is biased downwardly by a spring 54, in the direction. to open the contacts.

Connected to the space outside of cylinder 53 is a pipe 55, communicating with a pressure reservoir 56. The piston (Fig. 1C) is supplied with piston rings 5'! and cooperates with a sealing gasket 58 for a purpose to be described below. In the sides of cylinder 53,'at the upper end, are ports 59, which at times communicate with a passage 60 in stem 5|, which passage 60 terminates, at its upper end, in two branches 6|, each one adjacent the place where a fixed and a movable contact bears against each other. e

The brake pipe, BP, and the main reservoir pipe MR, are supplied, respectively, with valves 62 and 63, which are to, be manually operated, upon two cars being coupled, to move their through ports in line with the pipes they control. The check valve H, can be of any usual construction, and functions, when the brake pipe cut- 1 out valve is in its out position, to prevent leakage of pressure from the equalizing reservoir, back into the brake pipe under. unusual conditions, such as with the brake pipe cut-out valve in off position, RPV picked up, and thebrake valve in release position, instead of in handle off position as'it should be. I

To summarize what has been explained above, with regard to the equipment'on each cab, with cab A cut into service by meansof its brake pipe cut-out valve, and with cab B cut out of service by means of its brake pipe cuteout' valve, together with proper operation of the directional switches, as will be dealt with in the following description, it may. be helpful to consider the conditions existing. f 1

In Fig. 1, with regard to cab A, the engineers brake valve EBV is shown .with its handle in service position, and the master controller MC has been shown with its handle in its off position. However, they have been so shown for facilitating explanation below, and it should be borne in mind that under normal operation, the engineers brake valve is in the position shown in Fig. 2, that is, with its handle in release position} and the master controller has its handle in the on position, whereby to move drum 23, so that contact-segment 24 makes contact with the contacts 64, so as tocomplete the propulsion circuit.

In this cab A, with the brake pipe cut-out valve, as shown, in its in position, the engineers brake valve is connected tothe brake pipe so that the valve can be operated to; reduce pressure in the brake pipe and apply the brakes inthe usual manner. The main reservoir is connected, by means of pipes MR. and 65, to the chamber 66 in the brake valve lying abovetherotaryvalve 67.

In this in position, the EPV .is energized, whereby to hold its valve in its lower position, so as to close off the port 3| leading to atmosphere and to interconnect passages Band I so as to put brake pipe pressure in chamber 4| of the emergency application valve EAV, I

The suppression relay SR has its pipe 38 conpassages 66 and 61 tothe equalizing reservoir,

whereby to compress the spring 35 to permit the closure of contacts 33-34, so that the suppression circuit, as will be more clear .from the following, is closed.

The power-off relay POR, has its pipe 3 connected, through the brake pipe cut-out valve, to receive brake pipe pressure, whereby to close its contacts, and complete the propulsion control circuit through the master controller MC.

In cab B, where the brake pipe cut-out valve is in the out position, the engineers brake valve is blanked off from the brake pipe by portion I5 The suppression relay SR has its pipe 39 connected to the adapter E and thence through passages 66 and 61 to atmosphere, whereby to open the suppression circuit, as will appear clear,

below. v l

The power-oil relay POR has its pipe I1 connected through the brake pipe cut-out valve, to atmosphere, whereby its contacts are open, and the propulsion circuit is therefore open, as will appear clear, below.

The EPV has its winding 21 deenergized due to the operation of the directional switch on this cab to the Cut Out position, and hence the chamber 8 is connected to atmosphere, while passage 9 carrying brake pipe pressure, is blanked off from passage 1 As a result, the emergency application valve lilAV momentarily opens, but thepipes 4B and 68 leading to the passageway 69 of the engineers brake valve EBV is blanked oil by the rotary valve 61, and hence air pressure is not lost through the emergency application valve.

'Thus, in the cab 13, which is out out of service, control of the brakes is taken away from the engineers brake valve, as likewise is control of the brakes taken away from the master controller and the electro-pneumatic valve, and the power-oil relay is connected to atmosphere to cause it to open its contacts.

While running with the engineers brake valve in release position, air pressure from the main reservoir passes through pipes MR and 65, to cavity 66 in the brake valve above the rotary valve 61. In this release-position, as shown in Fig. 2, it can be seen that this pressure passes through passage 10 to charge the brake pipe BP, through passage H to charge the Equalizing reservoir, and through passages H and 12 to charge the chamber 13 above the reduction limiting valve 14. At the same time, the Reduction limiting reservoir, and the chamber 15 beneath this valve, which are constantly intercommunicated by passages 16, 11 and 18, are connected by passages 19 and 80, to the passage 61 leading to atmosphere ATM. Also pipe 39, leading from the suppress'on relay SR communicates with atmosphere through passages B6 8| and 61 As can be readily understood from Fig. 1D, with the brake valve handle in service position, as show, the equalizing reservoir is connected to chamber 13 above the reduction limiting valve, to pipe 39 leading to the suppression relay SR, and to atmosphere through a restricted opening 82 and the passage 61 At the same time, main reservoir pressure in cavity 66 passes through opening 83 to build up pressure in the chamber 15 beneath the reduction 1imiting valve, and in the reduction limiting reservoir through passage 16.

Also in this service position, the brake pipe BB is connected, by means of pipe I3, and passages84, 85, 86 and 81 to passage 61 leading to atmosphere, whereby to produce braking in addition to the usual action of the equalizing piston.

As soon as pressure beneath reduction limiting valve 14 builds up sufficiently to overcome the decreasing pressure above this valve, the valve moves upwardly to thereby blank off pipe 39 leading from the suppression relay, and other pipes so .as to prevent further reduction in brake pipe pressure, and in pressure in chamber 13 above-valve 14, and to prevent .further building up of pressure in the reduction limiting reservoir, and chamber 15 beneath valve M.

It is clear from the above, that upon positioning the brake valve handle in service position, the suppression relay SR is operated toclose its contacts 33-34, and that if the handle be returned to lap, for example, before the reduction limiting valve 14 has operated, the suppression relay is reconnected to atmosphere, and its contacts open. However, if the handle of the brake valve be left in service position long enough to produce a full service brake application, which results in movement of the reduction limiting valve 14, then the handle can be returned to lap, for example, and the suppression relay contacts will stay closed until sufficient pressure leaks out of chamber 38 to permit the spring to open them. The reduction limiting valve permits the engineer to leave the valve in service position during suppression without reducing brake pipe pressure below equalization.

Referring now to the essentially electric portions of the system, there is represented therein a stretch of track constituted by track rails 81, on which is a vehicle, indicated by the wheels and axles 88 and 89, thesetwo sets of wheels and axles being at the two ends of a car having the two cabs A and B.

The wayside apparatus for applying coded train control energy to the track rails M has not been shown, since it can be of the type shown, for example, in the patent to T. J. Judge, No. 2,141,535, granted December 27, 1938. This wayside apparatus provides means, as in Judge, above, for placing alternating current, of a frequency different from the usual commercial frequencies, such as cycles per second, on the track rails in coded form constituted by interrupting the current periodically at various rates. The particular codes involved in the present system are those having a rate of 180, and 75 interruptions per minute. The system is so arranged that a car in an occupied block, and in the block immediately to the rear of an occupied block, will receive no train control energy at all; one in the second block to the rear of the occupied block, will receive the '75 rate code; in the third block to the rear of the occupied block, the 120 rate code, and in the fourth block to the rear, and all the blocks to the rear thereof, the rate code.

Furthermore, there can be various overlaps if desired, such, for example, as having two successive blocks receive the 120 rate code, similar to Judge, above.

Also involved in the trackway apparatus, is means for automatically operating a non-signal, or cutout relay, for cutting out train control restrictions in territory which is not signalled, and this can comprise a short section of track, or a wave wire, or loop, at the entrance to non-signallecl territory, which is always supplied with coded energy at a particular rate, such, for example, as 240 per minute.- Thistrackway ar- 37 -5.: 99, the ampli-filter m0, wires IOI and m2, conrangement can be in general in accordance with the patent to W. W. Wenholz, No. 1,692,361, granted November 20, 1928; or W. K. Howe, No. 1,593,553, granted July 20, 1926.

The car carried apparatus includes a pair of receivers 89 carried in front of the wheels and axle 88 of cab A, and a pair of receivers 90, carried in front of the wheels and axle 89 of cab B. Each receiver is positioned, with respect to the track rails, so as to inductively pick up train control energy from the track rails, and receivers'89 by means of wires 9!, SH, conducts this energy to the receiving and decoding means involved in the system. In like manner, the receivers 90'conduct the inductively received energy through wires 92, 92 to the receiving and decoding means.

As stated above, each cab has a directional switch Direc. Sw., which is hand operated, the switch for cab B having contacts 93 and 94, which are shown in the cut out position, whereby to cut out the receivers 90 for cab B from communicating with the receiving and decoding apparatus. "I'he directional switch for cab A has contacts 95-and 96, which are shown in their cut in position, whereby to connect the cab A receivers to the receiving and decoding circuits.

The receivers 90 for cab B are disconnected from the receiving circuits by contact 94 having opened its front point. Receivers 89 however, for cab A, which cab is cut into service, is connected to the receiving circuits by means of wires 9I 91, contact, 93 and back pointywires 98 and tact finger I03 and back point, wires I04, I05 and I06, contact 96 and front point, wire 9|, and back to the receivers 89 9 The ampli-filter I is an amplifier and filter, and is arranged to allow only 100 cycle current to pass through it with any freedom, and amplifies the energy received by means of one or more stages of ,tube amplification, and can be of the general type, for example, as shown in the patent to O. H. Dicke, et al., No. 1,942,138, granted January 2, 1934.

The out-put from ampli-filter I00 passes, by wires I01 and I08 to a full-wave rectifier I09, the out-put of which passes through an obvious circuit to a code relay CR, which follows the code, and picks up and releases as the code energy is put on and cut off, whereby to vibrate its contact fingers I I0 and I I I at the same rate as the code. For example, this relay picks up and releases 180 times per minute when the 180 code is in force; and likewise for the other codes. 7

If av plurality of cars be coupled together to constitute a train, then all of the directional switches must be moved to cut-out'position except the one in the cab, at the front of the train, and all of the brake pipe cut-out valves must be operated to the out positions, in order to permit the train to proceed, as is obvious from the above, and the following description.

When relay CR is in picked-up position, it energizes a front repeater relay CRFP, through a circuit which is obvious from the drawing, and which includes contact finger I I I and front point of relay CR. This front repeater relay is made slow to release by means of a resistance I I2, connected across its windings, and, as indicated in the drawings, this relay has a release time of approximately .6 second.

With relay OR in released position, and with relay CRFP picked up, the '75 rate relay 15R, is

energized throughv a' circuit including contact finger III and back point, and contact finger II 3 and front point of relay CRFP. Relay 75R is made slow to release in the same manner as is relay CRFP, and'it also'has a release period of about .6 second. I

With relay 75R picked up, a circuit is completed for energizing its repeater relay 15RP, which includes contact finger I I 4 and back point of an .lay I5RP and'is picked up through a circuit including contact finger I I1 and front point of relay I5RP, and this relay is slow to release and has a release time of approximately 2.0 seconds.

In designating the operating times'of the various relays, as above, and in the following description, it should be realized that these times are not necessarily fixed, and may vary widely, so long as the relationship between the times of the various relays is maintained within limits. Accordingly, times are given for merely one set of times, in

which the times bear the proper relationship for proper functioning of the system.

Returning now to code relay CR, this relay, through its contact finger IIO, operates'a pushpull transformer arrangement, through a circuit obvious in the drawing, and including a checking contact I I8 and front point of relay R. This push-pull transformer functions as in the patent to O. H. Dicke, et al., above, for example, so as to have first one part, and then the other, of its primary energized, respectively, first in one direction and then in the other, whereby to pass coded energy through the secondary of this transformer II9 to tuned circuits I20, I2I and I22, which circuits are respectively tuned for energy coded at the rates of 120, 180 and 240 a minute. These tuned circuits include the primaries of transformers I23, I24 and I25 respectively, the secondaries of which are connected to thein-put sides of full-wave rectifiers I26, I27 and I28. out-put sides of these rectifiers are connected across the windings respectively of the rate relays IR, I80R and the non-signal control relay 240R, whereby these rate relays respectively pick up when codes of 120, 180 and 240 are in force.

If, for example, code at the rate of 120 a' minute is being received, the rate relay I20R will pick up to thereby pick up its repeater relay 5 20RP, by energy passing through the back point of the acknowledging relay ASR, to thereby pick up the repeating forestalling relay I20FP, which is interlocked with the forestalling repeating relay I80FP.

The pick-up circuit in this case for relay, I20FP includes contact finger I29 and back point of acknowledging relay ASR, contact finger I 30 and front point of rate relay 15R, relay winding I20RP, and contact finger I3I and front point of relay I20R.

The pick-up circuit for the I 20FP relay includes contact finger I32 and back point of I80RP, and contact finger I 33 and front point of relay 5 20RP. All these relays are slow to release, as indicated, and have release times approximately as indicated.

' In a similar manner, if 180 code is being re- The I I'II) Here again it is seen that I80RP is interlocked with the 120 rate group, and cannot pick up unless I20Ris down. i

If a car should enter non-signalled territory and encounter a short period of code at the rate of 240 per minute, the non-signal control relay 240R will pick up through its obvious circuit.

The various rate relays, with their repeaters, and their repeating forestalling relays, which correspond to the three train control codes of 75, 120 and 180, are so circuited and interlocked as as to facilitate a code producing an effect on the train if the code is a change to a more restrictive one, but to make it more di'fficult to produce such an effect if the code is a change to a less restrictive one.

For example, if 180 code is in effect so that the'180 group ofrelays are up, that is, I80R, 'I80RP and I80FP, and the code changes to a more restrictive one, such'as 120, the I20R relay can pick up immediately through a front point of I80FP, the circuit including one side of the rectifier I26, wire I38, relay I20R, wires I39'and I40, and contact finger I4! and front point of relay I80FP, to the other side of the rectifier.

If it were not for the I80FPrelay being up it would be necessary for the I20R relay to pick up in response to its code, through a local circuit including the resistance I42, this circuit including the rectifier I26, wire I38, relay I20R, wire I39, resistance I42, and wire I43. This last traced pick-up circuit for I20R, including the resistance, decreases the sensitivity of the relay and requires that the'l20 code shall have been in force longer, in order to have the effect of picking up the relay.

I Thus, onthis change to more restrictive, name- 1y, from 180 to 120 rate, the 120 rateis facilitated in having its effect immediately on the control by picking I20R up through the I80FP up, and not being under the necessity of picking up through the resistance I42, as would be the case if the change were from a '75 rate code to a 120 rate code.

From the above, it can be seen that the relays in the I20 rate group and those in the I80 rate group are interlocked so that therepeater relays and the forestalling repeaters of each group can be operated only so as to enforce the speed limit peculiar to the code in force, as will appear more clear as the description progresses.

The relays belonging to the '75 rate code are not interlocked with those of the I20 and the I80 group, since the I5 group relays are energized with all codes, as is obvious from the circuit arrangement described above.

Considering a further change to a more restrictive condition, namely, from 120 rate to 75, the I20 rate group of relays will release and the I5 rate relays which are already up, will stay up and a further speed restriction wil1 be imposed.

Upon traveling under the 75 rate code and passing from block to block, the periods during which current isoff may be so shortened as the receiver passes overin'sulating joints, as tosimulate, for example, the 120 rate code, for a momentary period of time. In these circumstances, it is most unlikely that the rate relay I20R will pick up, since the pick-up circuit for I20R, which is then available, is'that through the desensi tizing resistance M2.

Due to other reasons there may be a momentary simulation of the 120' rate code as, for example, with approachcontrol of the coders, the code motor starts from rest and comes up to speed in the course of a very short time, but during this time the code passes from a zero code rate to the rate desired' In passing, for example, from '75 rate code to 180 rate code, the coder which ultimatelyapplies 18'0 rate code passes through af'period when the code-appears to be 120' ratefbut this is onlymome'ntary and due to the resistance I42 and the circuit arrangement, the rate relay I20R will" not erroneously pick up.

On passing from the "75 rate to the 120 rate code I20R will pick up through its resistance and then later, when I20R P has picked up, it will have the resistance I42, shunted out by contact finger I44 and front point of I'ZIIFPn Thus, relay I20R is made to pick up with difficulty, and tohold up with ease, whereby to insure that it shallnot pick up unless it "is authorized to do so by an authorized code, and will not release unless it is certain that the authorized code, which picked it up, has been definitely changed to a different code.

If running under 120 code and on passing from block to block, the 120'rate should simulate the 180 rate, even if the I80R relay should pick up, the other relays in thi's I80 group, as IBORP and I80FPcould not pick up, since for themto do so requires that I20R be down, and with 120 rate code in effect IZDR isup and will stay up.

It will benoted that 'the'energy for picking up any of the repeater "or forestalling relays of the 15,120 and I80 group must 'pass through a back point of the acknowledging stick relay ASR. Since, when no code is'present, and operation is in the most restrictivezone, it has been necessary to acknowledge and pick up the stick relay ASR, as will appear more clearly below,it follows that in order to change from the most restrictive condition to a less restrictive condition, whether it be 75 rate, 120 rate, or 180'rate, a considerable time, amounting to several seconds, must elapse in order that relay ASR release. before the less restrictive condition can be set up inthecab.

Involved in'this system of train control is a speed control which includes'various contacts operated'by a speed governor which can be driven from'the' car wheels or'axle and controls these contacts to open or close, as the case may be, at various speeds of car travel. This governor can operate the contacts in any usual manner, and canbe of'the type, for example, as described in the patent to Richmond, 1,409,969, granted March 21, 1922; or the patent to Estwick, above referred to. 1 v

For limiting the speed of the car there is a series of contacts,- which, in cooperation with contact fingers of the various FP relays, produce an emergency brake application if the speed be exceeded. This group of speed control contacts includes a contact I44 which is open when the speed exceeds 3'? miles per hour, a contact I45, open above 2'7 miles per hour,'a contact I46 open above 18 /2 miles per hour, and a contact I41 open above 12 /2; miles per hour.

These; limiting speed contacts are in series, respectively, with contact finger I48 and front point of relay I 80FP, contact finger I49 and front point of relay I FP, and contact finger I50 and front point of relay 15FP, (the contact finger 150 and front point tain speeds which are slightly below the limiting speeds, in order to give warning to the engineer whereby to have relay I80FP up,

that h is approaching the limiting speed and hence approaching an emergency brake application unless care is taken.

-' One set of such contacts includes contact I52,

which closes above miles per hour, contact I53, which closes above 25 miles per hour, contact I54, which closes above 16 miles per hour, and contact I which closes above 10 miles per hour, and which, when closed, and depending on the various other controlling conditions, as explained below, result-in the energization of a cab signal W, in each of the cabs, to display a lunar white light, thereby to apprise the engineer that' he is approaching the limiting speed.

-I'he other set of contacts referred to, includes contact I56, which closes above 36 miles per hour, contact I I51, which closes above 26 miles per hour, contact I58, which closes above 17 miles per hour, and contact I59, which closes above 11 miles per hour. These last referred to contacts, when closed, and subject to other controlling'contacts, result in the energization of anaudible signal SA in each of the two cabs, Which'signal may be of any distinctive type, such as a bell, as illustrated, the bell sounding when energized," g

As typical of this speed control system, it can be seen that-the speed contact I44 which opens above 37 miles per hour'and results in an emergency brake application, as will appear more clear below, is associated with the speed contacts I52, and I56, which close, respectively, above a speed of 35 miles and 36 miles per hour; Thus, when operating under the I code, so that a speed limit of '37 miles per hour is imposed on the car, should the engineer exceed the authorized speedof 35 miles per hour, speed contact I52 closes, to thereby energize the lunar white cab signal W, and apprise the engineer that he is approaching the speedlimit. Upon the speed continuing to increase, to exceed 36 miles per hour, speed contact I 56closes, to thereby sound the audible signal SA, and'apprise the engineer that he is still more closely approaching the speed limit. In the same manner as above, when operating under ratecode, 75 rate code, andunder no code, the speed'limits of 27, 18 and 12 miles per hour, are set up and the limiting speed contacts M5, I46.and I41 are in force, and cooperate, respectively,

speed contacts I53-I 51, l54- I58 and I55I59.

It can be seen from the above that when running under any particular code, the code responsive, relays .thereunder determine .a limiting speed by means of the FP relays and operate an authorized and warning'signal by means of the RP relays, the limiting speed being such, be-

cause, if this speed be exceeded, subject to suppression, as described below, the relay EPVR will become deenergized, to thereby deenergize with the authorized speed contacts and the warning In each of the cabs is a cab signal which can display various aspects. Considering the signal in cab A, it can be seen that this signal includes, in addition to the lunar white signal W, which is lighted when the authorized speed is exceeded, and the audible bell signal SA, which is sounded when the warning speed is exceeded, an audible acknowledging signal AA, which may be a buzzer, or something distinctive from the bell signal SA, and which, as will appear below, is energized and sounds when acknowledging should be performed. There is also a signal V, which, when energized, shows a violet light, for example, and is energized when operation is occurring in nonsignaled territory and the non-signal relay NSR has been energized in order to relieve the vehicle from signal and speed control.

In addition to the above, the cab signal includes four signals G, Y/G, Y, R, which increase in restrictiveness, in the order named, and may also be designated by authorized speeds, as, respectively, 35, 25, 16 and 10 /2, and are energized, respectively, when operating in territory having code, 120 code, 75 code and no code.

The relay EPVR, which is normally energized, and which, upon becoming deenergized, causes an emergency brake application, is energized normally through one or more of several multi-' ple circuits, in accordance with the territory through which the car is passing.

Assume that the 180 code is being received and that'the speed is not above 37 miles per hour. Relay EPVR, is energized through a stick circuit including its contact finger I60 and front point, contact finger I48 and front point of relay I86FP, and the limiting speed contact I 44. If the 75 codev is being received, the energizing circuit passes through contact finger I60 and front point, contact finger I50 and front point of relay 15FP, and the limiting speed contact I46, whereby the speedlimit is 18 /2 miles per hour, instead'of 37 miles per hour, since under 75 code, both the contact fingers l48 and I 49 of relays I BOFP andcloses tothereby energize the audible bell signal, or warning signal, SA, through a circuit including contact finger NH and back point, wires I62, I63 and I69, speed contact I56, wires I16, contact finger HI and front pointof relay IBORP, and wires I12 and I13. I 1

Assume now, despite the warnings, the speed continues to increase, so as to be not'less than 37 miles per hour, whereupon speed contact I44 opens to open the stick circuit for relay EPVR, whereupon it releases its contact finger I14, breaking the energizing circuit for the EPV for cab A, which circuit includes'the winding 21 of EPV, wire I15, directionallswitch contact I16 of cab A and front point, wire I11, EPVR, contact finger I14 and front point, wire I18, directional switch contact I19 of cab B and back point.

Upon the EPV of cab A becoming deenergized, the springs 28 and 29 cause the valve to vent chamber M of the emergency application valve EAV, to atmosphere, through port 3| of EPV, whereupon valve 43 raises from its seat to vent the brake pipe to atmosphere through port 41, and thus produce an emergency brake application.

If the warning had been heededby the engineer before he reached the speed limit of 3'1 miles per hour, and he had moved his engineers brake valve handle to service brake application position, as shown in Fig. 1D, and had moved his master controller handle to the off position, as in Fig. 1, a suppression circuit would have been completed for maintaining relay EPVR energized regardless of the opening of the speed contact I44. However, with the brakes applied, the speed would not have even momentarily reached thelimit .of 37 miles per hour unless operating on a down grade.

The suppression circuit referred to for energizing relay EPVR, including wire I80, contacts 33 and 34 of the suppression relay SR in closed position, wire IBI, contacts 25 of MC in their closed position, wire I82, cab A, directional switch contact I83 and front point, wire I84 contact finger I85- and front point of EPVR, wire 220, and the winding of EPVR. This suppression circuit includes a front point of the relay EPVR and hence is effective only if completed before EPVR releases.

With EPVR held up, the contact finger I14 remains up, and thus the deenergization of the EPV for cab A is prevented, and thus the emergency brake application is forestalled.

Assume now that while operating under 180 code, at a speed of perhaps 34 miles per hour, the code changes to the 120 rate, whereby to cause the 180 group of relays to release and the 120 group of relays to. pick up. Upon the release of the 180 group relay I80RP, its contact fingers I 65 and HI make up their back points. Since, at this time, the 120 group relay IZURP is already up, so that its contact fingers I84, I83 are making up their front points, and since the speed is high enough for the speed contacts I53 and I51 to be closed, circuits will be completed for the authorized speed warning signal W, and the warning speed signal SA, through circuits which are obvious from the drawing, to thereby apprise the engineer that his speed is excessive and that he must act promptly to forestall an emergency brake application.

Upon the release of relay I80RP, which gives the warning to the engineer, relay I80FP is deenergized, to release two seconds thereafter, and thereby deenergize relay EPVR, unless the speed be below 27 miles per hour, and upon deenergization EPVR releases .5 second thereafter, to pro duce an emergency brake application as explained above. During this period of time of sequential release of I80FP and EPVR, amounting to 2.5 seconds, the engineer can forestall the emergency brake application by moving his engineers brake valve handle to service brake application position and moving his master controller handle to the off position, whereby to complete the suppressive braking circuit traced above, and forestall the emergency brake application.

Assuming the engineer acts promptly the emergency brake application is forestalled and upon the speed being reduced below 25 miles per hour the signals W and SA are both deenergized ,on the car.

and .the engineer knows that he is within safe speed limits and can release his brakes and operate his master controller handle as he desires.

In other changes from one code to another, the conditions outlined above are similar and the requirements are similar. It is to be understood, of course, that, when going from onecondition to a less restrictive condition, there is no occasion for action on the part of the engineer, because his speed limit, in that case, instead of being suddenly reduced, is suddenly increased, thus, to allow him even wider latitude in the operation of his car We can now assume that after operating in territory where 7 5 rate code is being received, and the speed is maintained under 18 /2 miles per hour, territory is entered in which no code is present. In these circumstances the '75 rate group of relays all release and upon the release of 15FP, a speed limit of 12 /2 miles per hour is imposed Since none of the FP relays is energized, the energy for relay EPVR passing through its contact finger I60 and front point cannot reach the relay and it is necessary to receive energy for the relay EPVR over wire I84 and contact finger I05 and front point of the acknowledging stick relay ASR. Not only is this necessary but it is also necessary that the speed be within 12 /2 miles per hour in order that speed contact I41 shall be closed.

Hence, under these conditions, if the speed be above 12 miles per hour, whichmay, of course, be the case, it is necessary to have recourse to suppressive braking, as described above, and then before the suppressive braking is discontinued to operate the acknowledging contactor Ack. C., in order topick up the acknowledging stick relay ASR.

Assuming that suppressive braking has been accomplished, if necessary, and that the speed is not above 12 miles per hour whereby speed contact I41 is closed, we can next assume that the acknowledging contactor is operated.

Under the conditions assumed, the back repeater relay BPR is up. This relay picks up through any one of the three contact fingers I86 of relay 15R, I81 of relay CRFP, and I88 of relay EPVR, and their back points, these contacts all being in multiple, and the two acknowledging contactors I89 and I90 for the cabs B and A, and their front points, in series. The pick-up circuit for BPR, therefore includes acknowledging contact I90 and front point, contact finger I86 and back point, the winding of BPR, Wire I9I, and acknowledging contact E09 and front point.

When up, BPR sticks up independently of the acknowledging contacts, but dependent upon back points of the acknowledging stick relay ASR, through a circuit including contact finger I92 and back point of ASR, contact I93 and back point of BPR, contact I86 and back point of 15R, thewinding of BPR, contact finger I93 and front point of BPR, and contact finger I92 and back point of ASR.

The occasion for acknowledging has been brought to the attention of the engineer in a forcible manner by the sounding of thesignal AA, which is audible, and may be a buzzer or the like, and at least of a type to be distinguished from the bell SA. With no codes present, these signals AA, in each of the two cabs, are energized through a circuit including contact finger I94 and back point of relay NSR, contact finger I95 and back point of relay 15RP, contact finger I96'and front point'of BPR, contact finger I97 and back point of ASR, and the wire I98.

on hearing the buzzer AA the engineer realizes that acknowledgment must be performed before the suppressive braking has been released, or otherwise the relay EPVR will become deenergized and produce an emergency brake application. The engineer therefore depresses the acknowledging contactor of his cab (B), which is pedal operated, to thereby pick up acknowledging stick relay ASR through a circuit including acknowledging contact I99 and back point, contact finger 20! of relay BPR and front point, contact finger 2IJI and back point of NSR, contact finger 202 and back point of 246R, wire 203, and the winding of ASR.

After being picked up, relay ASR sticks up through a circuitincluding contact finger 204 and front point of ASR, contact finger 205 and front point of BPR, contact finger 21135 and front point of EPVR, and contact'finger 2M and back point of N SR. p It is necessary that the acknowledging contactor be promptly returned to its normal position since the picking up of relay ASR has broken the stick circuit for relay BPR and the pick-up circuit of relay BPR is dependent upon the acknowledging contactor being positioned in its normal position so as to close Contact I89 on its front point. Unless the acknowledging contactor be promptly returned, the picking up of relay ASR deenergizesrelay BPR which releases to thereby break both the pick-up and stick circuits of BPR, which then releases its contact finger I85, and deenergizes relay EPVR, with an emergency brake application as the result.

If, however, the engineer properly returns the acknowledging contactor, acknowledging stick relay ASR stays up and with the speed, not exceeding 12 miles per hour, relayEPVR remains energized through a circuit including wire I 84*, contact finger I 85 and front point, and the various speed contacts I41, I46, etc. in series,to thereby preventemergency brake application.

After acknowledgment, as described above, the engineer may proceed within the 12 mile speed limit so long as the danger or no-code conditions exist. As soon as any code is received, the rate relay IER, for example, will pick up to thereby drop the back repeater relay BPR, which in turn will drop the acknowledging stick relay ASR. It is only afterthese two relays have released that energy through contact finger H4 of relay AS-R is available to pick up the RP and FF relays un der the "75 rate group and set up a speed limit of 18 miles per hour and remove the operation from the danger (acknowledgment) condition. Since these relays BPR and ASR are slow torelease, it can be seen that several seconds elapse after a code has been received before it sets up its particular speed limit, and thus it is assured that operation in red territory will not be -rnistakenly discontinued by any temporary pulsating energy on the track rails, as a transient code or such as to momentarily simulate a code.

It wasdescribed above that at times the car may-operate in territory which is not signaled,

and in which there is no trackway apparatus for applying coded train control current to the track rails. In order to permit the engineer to pro ceed on his own initiative, and freefrom the restrictionswhich such conditions place constantly on the car, the entrance to .each such zone is provided with a loop, or a short track above 12;

section, as above described, 'to which coded current at the rate of 240 per minute isapplied.

T 'Let us assume that the car enters such a territory, and upon encountering the 240 code, relay 240R picks up as described above} With relay 26H up, relay NSR picks up through a circuit including wire 208, contact finger 209 and front point of relay 15R, contact finger 2H) and back point vof relay ASR," contact finger 2H and front point of 24R,'and' the winding of relay NSR. T g 1 Upon leaving the 240 loop, relay 240R releases, as also does relay 15R. The release of relay HR causes the back repeater'relay BPR to pick up, whereupon a stick circuit is completed for relay NSR.which includes contact finger H2 and front point of relay BPR, contact finger M3 and front point of NSR,'contact finger 2M and front point of' EPVR, contact finger 2H .and back point of 248R, and the Winding-'ofNSR.

With relay NSR up, contact finger W3 of this relay is picked up, whereby to include a variable resistance H5 in the receiving circuit passing to the amplifilter, and-thus to reduce the sensitivity of the receiving circuit while traveling in NS territory so as to further assure that no unauthorized pulses of current will haveany effect on the car carried apparatus.

Also, with relay NSR up contact finger I94 thereof is up, to thereby break the circuit for energizing the acknowledging signal AA, so as to prevent this signal from sounding. Also, with contact finger N6 of relay NSR in its picked up.

position, the energy for the signals G, Y/G, Y

and R, which passes through a back point of this finger, is removed from these signals; and this energy passes, through the front point of 2I6 and wire 2|! to energize 'the'signal V, which can display, when energized, a violet light, to indicate to the engineer that he is traveling in NS territory.

Under NS conditions, as described above, relay EPVR is directly held up through contactfinger Hit of NSR and front point and wires 2H3, 2I9,

2%, etc., whereby to avoid any deenergization of the EPV, with a resulting brake application. I

It will be noted that the stick circuit for relay NSR includes a front point of back repeater relay BPR, and accordingly, shortly after a code is received, relay-BPR. will release to thereby cause NSR to release, and .bring the car-junder speed control, in accordance with the particular code enforced.

An additional condition sometimes exists which must be cared'for, and occurs Where a car may be cut into service while in NS territory, and hence the car cannot experience a period of 240 code, to set up NS conditions. To care for this situation, the NSC or non-signal contactor has been provided. Under the conditions assumed, a

that is, nocode in force, the acknowledging signal AA will sound by virtue of the circuit traced above. To silence this signal, the acknowledging contactor will be depressed, and then restored to its normal position, to thereby pick up and stick up acknowledging stick relay ASR.

Also, with relayfASR up,

miles per hour, relayEPVR is picked up and held up.

The NS contactor NSC will then be operated, this contactor being relatively inaccessible, and operable by the brake valve handle, which can be removed from the brake valve only after having been turned to a position to have first pro duced a full service brake application. Operaand the'speed not tion of contactor NSC picks up relay 240R through a circuit including directional switch contactor 2m and front point, NSC contactor H9 and back point, contact finger 220 and back point of relay 15R, and the winding of relay 240R.

With 248R up, the acknowledging stick relay ASR up, a pick-up circuit is completed for relay NSR which includes contact finger Z|8 and front point, contact finger H9 and back'point, contact finger 2 Ill and front point of relay ASR, contact finger 2| I and front point of relay 240R, and the winding of NSR.

Upon the release of contactor NSC, relay 240R releases, and with relay EPVRup, a'stick cir cult is completed for relay NSR which includes contact finger H2 and front point of relay BPR, contact finger 2l3 and front point of relay NSR, contact finger 2 l 4 and front point of relay EPVR, and contact finger 2H and back point of relay 240R. v I

, It is necessary to return the NS contactor to its normal position, and thus cause the energization of NSR to depend upon the above traced stick circuit, since if an attempt were made, after operating the NS contactor, to leave it in operated position, the continued picked up condition of NSR would break the stick circuit for relay ASR at contact finger 201 and back point, whereupon relay ASR would release, and break the pick-up circuit for relay NSR at contact finger 2 l I and front point, whereupon relay NSR would release and the operation of the NS contact or would have produced no result.

Upon the train leaving-NS territory and entering coded territory, various of the code responsive relays will pickup, and since any code will pick up relays CRFP and 153, this will cause back repeater relay BPR. .to release to thus break the stick circuit for relay NSR, and restore the car to speed control in accordance with the code in force. This restoration occurs only a considerable time after the code has been first rereived, since, before the car is restored tospeed restrictions, it is necessary that enough time elapses for the sequential release of slow release relay BPR, and slow release relay NSR, or a matter of. about 5 /2 seconds.

The back repeater relayBPR, is'also up, when relay EPVR is down, and this provides a means for resetting after incurring an emergency brake application, by means of the acknowledging contactor Ack. C.

Assume, for example, that when traveling under a speed limit of, for instance, 27 miles per hour, that is, under the 120 code, the speed exceeds the 27 rnilelimit to cause the deenergization of EPVR and a'resulting emergency brake application. In order to reenergize EPV, and permit the car to proceed, it is necessary first to reduce the speed to at'least 12 /2 miles per hour,

whereby to close all of the speed limit speed contacts I41, I46, etc., and then to acknowledge so as to close the resetting'circuit for relay lilPVR at contact finger I85 and front point of .acknowl-' edging stick relay ASR. Since acknowledgement requires that relay BPR- be picked up, and since in coded territory, this would not be the case except for contact finger I88 and back point of relay EPVR being in the pick-up circuit or relay BPR, it follows that this provision is what makes resetting possible in this systemby use of the contactor Ack. C. v

From the above it can be'realized that an improved complete system of inductive train control, embodying acknowledgment,resetting, suppressive braking, and operation in non-signaled territory, has been provided.

The above ratherspecific description of one form which this invention can assume, has been given solely by way of example, and not, in any way, in a. limiting sense. It should be understood that this specification contemplates covering all such variations and modifications as may, from time to time, occur, so long as they are not specifically excluded from the invention by reasonable interpretationof the appended claims.

Having described our invention, we now claim:

1. In a coded train control system, in combination, car carried means including a' receiver positioned to receive train control energy from the trackway, decoding means responsive to energy in the receiver to impose one limit when the energy is coded and a lower'limit when the,

energy. is non-coded, normally inactive brake control means effective, upon an imposed limit being exceeded, to become active and cause an automatic brake application, an acknowledging relay, an acknowledging contactor positionable either normal or reverse, a slow'release repeater relay having a pick-up circuit closed when no code is present and the acknowledging contactor is normal, a stick circuit for the repeater relay closed when no code is present and the acknowledging relay is in released position, an. energizing circuit for the acknowledging relay including the contactor in reverse position and afront point of the repeater relay, a stick circuit for the acknowledging relay independent of the con-n tactor and closed only if no code be present, and a circuit for making the brake controlmeans inactive and including a front point of the acknowledging relay, whereby the acknowledging verse to its normal position.

2. In a coded train control system, in combination, car carried means including a receiver positioned to receive train control energy from the trackway, decoding means responsive to energy in the receiver to impose one limit when the energy is codedand a lower limit when the energy is non-coded, normally inactive brake controlmeans effective upon ,an imposedlimit being exceeded to become active and cause an automatic brake application, an acknowledging relay, an acknowledging contactor positionable eithernormal or reverse, a slow release repeater relay having a pick-up circuit closed when no code. is present and the acknowledging contactor is normal, a stick circuitfor the repeater vrelay closed when no code is present and the acknowle ing relay is released, an energizing circuit for the acknowledging relay including the contactor in reverse position and a front point of the repeater. relay, a stickcircuit for the acknowledging relayindepende t of the contactor and closed only if no code be present, a circuit for making the brake control means inactive and including a front point of the acknowledging relay, whereby theacknowledging contactor must be promptly returned to its normal position, and another pick-up circuit for the'repeater relay requiring, when closed, that the acknowledging contactor be normal and the brake control means be active, whereby-the acknowledging contactor can function as a reset means. I

, 3. In a coded train control system, in combination, car carried means including a receiver positioned ,tofreceive ,train control energy from the trackway, decoding means responsive to energy in-the receiver to impose one limit on the train contactor must be promptly returned from itsreoperation when the energy is codedand alower limitwhenthe energy is non-coded, normally inactive brake control means eflective upon an imposed limit being exceeded to become active and cause an automatic brake application, an acknowledging relay, an acknowledging contactor positionable either normalbr'reverse, a slow release repeater relay having a pick-up circuit V closed when no code is present and the acknowledging contactor is at normal, a stick circuit forthe'repeater relay closed when no code-is present and the acknowledging relay is at released, an energizing circuit for the'acknowledging relay includingthe c'ontactor at reverse and a'front point of therepeater relay, a stick circuit for the acknowledging relay "independent of the contactor and closed-only if no code be-present,-and a' circuit for making the'brake control means inactive and-includinga front point-of the'acknowledging relay, whereby the acknowledging contactor must be pro'mptly returned to its normal position, and apenalty'means made active by theabsence of code, and made inactive by the'energizatio'n of the acknowledging relay.

V 4.In acoded train control system, in combination, car'carried means including areceiver positioned to receive train 'control energy from' the trackway; decodingmeans responsive to energy inthe-receiv'er' to impose one limit when the energ y iscoded and a lower limit on train operation when-the energyis non-coded, normallyinactive brake control meansefiective, upon an imposed lirn'it being exceeded, to become active and cause anfautom'atic brakeapplication, an ac-- knowledging relay,'an acknowledging contactorpositionable either normal or reverse,-a slow releas.e-"repeater relay having a I pick-up circuit closedwhen no code is present and the acknowl-:

edging contactor is vatnorrnal, a stick circuit for the repeater relay closed-when no code is present and the acknowledging relayis released, an ener-- gizing circuit for the 'acknowledging relay including the contactor' atreverse and a front point of therpeater relay, a stick circuitfor the acknowledging relay independentof the contactor andclosed only if-no code be present,-'anda circuit for making the brake control means inactive and including a front point of the acknowledging re1ay,- whereby the acknowledging contactor 1 must be promptly returned to' its normal position, the.ac-

knowledgingrelay being slow to release, whereby,- the sulnofthe successive-release times of-theLre-; peater-relay and 'the acknowledging relay must elapse aftercode is initiated, before the said one limit-is imposed. 4 v

- a codedtraincontrol system, in combina tion, car carried means including a receiver-positioned to-receive train control energy from the trackway-, decoding means resp'ons'iveto energy in the-receiver toset up a speed limit fornenergy codedatone rate; a non-signal relay energized by the-response of'the decoding means to energy coded atianother rate,-'a normally energized brake control relay'effective, when deenergized, tocause an automatic brake application; a pick-up circuit for the-brake control relay including a front'point of the-'non-signal relayya stick circuitrfor the brake control relay opened it an imposed speed lirnit'be exceeded; an acknowledging contactor position to connect "the receiver i to the decoding means; an N. SLcontacto'r positionableeither norpositionable either normal orre-Verse,--'"a slow release-acknowledging relay the energized cond-ition of which is dependentupon the contactor being at reversejia directional switch operable to -.in-

mal orreversa-a circuit-for picking up the non signal relay requiring for its closure the directional switch to be in its fin" position, the N, S.

contactor at reverse and the acknowledging relay.

picked up, and a stick circuit for the non-signal relay requiring for its closure the N. S. contactor to beat normal, the acknowledging relay being dependent for its energiz'ation on a back point of the non-signal'relay, whereby the N. SJcohtactor must be promptly returned to its normal position.

6. In a coded traincontrol system, in combination, carcarriedmeans including a receiver positioned to receive train control energy fromthe t'rakway, decoding means responsive to energy in thereceiver to impose'a speed limit on the train; operation for energy coded at one rate, a non-signal relay energized by the response of the decoding meanstojenergy coded at another rate, I

directional switch be in its in position, the

N. S. contactor at reverse and theacknowledging relay pickedlup, and Ja sti'ck circuit for the non signal relay requiringifonclosure that the N. S;

contactor beat normaLl'the acknowledging relay being dependent forits energization on a.' back point of the non-signal relay, whereby the N. S;

contactor must be promptly returned to its normal position, arslow release'repeater relay, an" energizing circuit for the'r'epeater relay requiring, to be closed, thatino fcoded energy be received, the stick, circuit for the non-signal relay including a front point'of the repeater relay, whereby non signal control is removed by receipt of coded energy only after thefo'ccurr'ence of the sequential release of the repeater relay and the non-signal relay. 1

7. In a coded train control system, in combina-,

tion, car carried meansiincluding a receiver po si.

tioned to receive train-control energy 'fr'om'thetrackway, decoding means responsive to energy ln=the receiverzto set up aspeed limit for energy coded'atone'rate,;a non-signal relayen'ergizedf bythe response of the decoding means to energy coded at another rate, aqnormally energized brake control relay effective,'when deenergized to cause a 'brakeap-plication, a, pick-up "circuit for the brake control relay including a front point of the non-signalrelay, a directional'switch operable to in position to connect ,the rec'eiverjto the-decoding me'ans, anda variable, desensitizing means controlled by the non-signal relay and inserted in the connection between thereceiver and the decoding means whenthej-non-signal relay is' energized. V,

8. In a' coded'ftrain control system, in combination, car c'arriedfmeans including a receiver positioned-l to receive trainv control energyv from the' trackway, decoding "means, responsive to;

energy in the receiver to impose. limitson train operation a'dc'ordingtothe code, a brake control relay iefi'e'ctivefz' when '.deenergized' ;to apply the brakesg afimasterrcontroller"for control of car propulsion current, an engineers brake valve, a directional switch movable to in position to connect the receiver with the decoding means, means for deenergizing the brake control relay upon exceeding a limit imposed onthe car, and a suppression energizing circuit for the, brake control relay closed only upon cutting off propulsion current by the master controller, positioning the directional switch to its in position and operating the brake valve to its service position.

9. In a coded train control system, in combination, car carried means including a receiver positioned to receive train control energy from the trackway, decoding means responsive to energy in the receiver to impose limits according to the code in force, a brake control relay effective when deenergized to apply the brakes, a master controller for control of car propulsion current, an engineers brake valve, a directional switch movable to in position to connect the receiver with the decoding means, means for deenergizing the control relay upon exceeding an imposed limit, a suppression energizing circuit for the control relay closed only upon cutting off propulsion current by the master controller, positioning the directional switch to its in position, and operating the brake valve to service position, and means to maintain the suppression circuit closed after the brake valve has been moved to nonbraking position only if a full service brake application has first been effected.

10. In train control systems, in combination, a propulsion power circuit, a power off relay to control the circuit, the relay including, a casing, a cylindrical chamber in the casing, a contact chamber in the casing, a piston fitting the cylindrical chamber and slidable therein, a stem on the piston extending into the contact chamber, a contact carried by the stem, a coacting fixed contact in the contact chamber, means biasing the piston to open the contacts, a source of fluid pressure connectable to the piston chamber beneath the piston to move it to close the contacts, a pressure reservoir, a constricted passage at all times connecting the cylinder chamber to the reservoir, a non-constricted passage connecting the reservoir to the space above the piston, and a sealing means effective to close the non-constricted passage only when the piston is operated by pressure to its extreme position.

11. In train control systems, in combination, a propulsion power circuit, a power off relay to control the circuit, the relay including, a casing, a cylindrical chamber in the casing, a contact chamber in the casing, a piston fitting the cylindrical chamber for sliding therein, a stem on the piston extending into the contact chamber, a contact carried by the stem, a coacting fixed contact in the contact chamber, means biasing, the piston to open the contacts, a source of fluid pressure connectable to the piston chamber beneath the piston to move it to close the contacts, a pressure reservoir, a constricted passage connecting the cylinder chamber and the reservoir at all times, a non-constricted passage connecting the reservoir to the space above the piston, a sealing means effective to close the non-constricted passage only when the piston is fully operated by pressure, and a pressure blow-out passage in the stem, connected at one end to the space above the piston and at the other end terminating adjacent the contact carried by the stern for extinguishing arcs.

12. In a train control system; a car; a cab at each end of the car; a receiver for each cab and positioned in association with the trackway to receive control energy therefrom; decoding means on the car responsive to energyyin the receivers when connected thereto; a directional switch in each cab and movable to in position to connect its receiver to the decoding means; an engineers brake valve, an emergency appli cation valve, and a brake pipe cut-out-valve which latter is movable to in or out position, in. each cab; means, when a cut-out valve is at in position, to connect the brake valve and ap-' plication valve with brake pipe pressure, and when at out position to cut them off therefrom; a normally energized brake control means in each cab and effective, when its cab is cut in to cause operation of the application valve and apply the brakes, if it becomes deenergized; and an energizing circuit for each brake control means requiring, for closure, that its directional switch be at in position, and the other directional switch be at out position.

13. In a train control system; a car; a cab at each end of the car; a receiver for each cab and positioned in association with the trackway to receive control energy therefrom; decoding means on the car responsive to energy in the receivers if connected thereto; a directional switch in each cab and movable to in position to connect its receiver to the decoding means; an engineers brake valve, an emergency application valve, and a brake pipe cut-out valve which is movable to in or out position, in each cab; means effec-,

tive, when a cut-out valve is at in position, to connect the brake valve and application valve with brake pipe pressure, and when at out position to cut them off therefrom; a brake control means in each cab and efiective, when its cab is cut in, to cause operation of the application valve and thereby apply the brakes, if it becomes deenergized; an energizing circuit for each brake control means closed only when its directional switch is at in position; and the other directional switch is at out position, a master controller in each cab to control car propulsion current, and means whereby operation of the ap-, plication valve is effected unless the controller handle is held by the engineer in any operative position except its power-off position.

14. In a train control system; a car; a cab at each end of the car; a receiver for each cab and positioned adjacent the trackway to receive control energy therefrom; decoding means on the car responsive to energy in the receivers if the latter are connected thereto; a directional switch in each cab and movable to in position to connect its receiver to the decoding means; an engineers brake valve, an emergency application valve, and a brake pipe cut-out valve which is movable to in or out position, in each cab; means effective, when a cut-out valve is at in position,

to connect the brake valve and application valve with brake pipe pressure, and when at out position to cut them off therefrom; a brake con trol means in each cab and effective, when its cab is cut in, to cause operation of the application valve and apply the brakes, if it becomes deenergized; an energizing circuit for each brake cabcontrolling car propulsion current for its cab;

and pressure means to close the relay contacts whenthe cut-out valve is at its in position.

- 15. Ina train control system, a brake valve, brake control means effective when deenergized to apply the brakes, a suppression energizing circuit for the brake control means, a suppressionrelay controllingthe suppression circuit, and pressure responsive means for operating thesuppression relay to close the suppression circuit which includes an equalizing reservoir and a re-" duction limiting reservoir respectively connected to the space above and below the reduction limiting 'valve of the brake valve, means'operative when the brake valve is in release position, to buildup pressure in ,the equalizing reservoir and exhaust pressure from the reduction limiting reservoir, a pipe connecting an operating chamber in the suppression relay to the brake valve and operating to exhaust the operating chamber to atmosphere with the brake valve in .release position, means, when the brake valve is in service position, to connect the equalizing reschamber and atmosphere, even though the brake valve be returnedto release position.

16. In train control systems, a car carried receiver positioned to receive energy, coded at different rates, from the trackway, a decoder responsive to the energy in the receiver in a distinctive way for each code; three contacts positioned in accordancewith car speed, for coacting with the decoder when responding to each code, there being, for each code, an authorized speed limit imposed by the decoder and one of said speed contacts, a warning speed limit imposedby the decoder and a second of said speed contacts, and a limiting speed limit imposed byi 45 the decoder and the third of said speed contacts,

a signal for each warning and authorized limit, means energizing the signals upon their limits being exceeded, and a brake control means effective to apply the brakes upon the limiting 50 speed limit being exceeded.

17. In train control systems; a car carried 're-' ceiver positioned to receive energy, coded at different rates, on the trackway; a decoder responsive to the energy in the receiver in a distinctive 1 Way for each code; three contacts controlledby car speed, for coacting with the decoder when responding to each code; and circuit means for each code for causing an authorized speedlimit tobe imposed by the decoder and'one of said speed contacts, a warning speed limit to be imposed bythe' decoder and a second of said speed contacts, and a limiting speed limit to be imposed by the decoder and the third of said speed contacts; a signal for each of said first two limits;

means energizing the signals upon their limits being exceeded; a brake control means effective to apply the brakes upon the limitingspeed limit being exceeded; a propulsion circuit, and suppressing means for preventing the brake control ervoir to the operating chamber, and also to at-,

means from becoming effective and including an energizing circuit closed, only if the brakes be applied manually, and the propulsion circuit to be opened.

18. In a train control system, in combination, a car carried receiver positioned to receive train control energy, variously coded to produce different degrees of restriction on train operation, from the trackway, decoding means distinctively responsiveto the variously coded energy in the receiver and to the absence thereof, the decoding means including a least restrictive relay, a more restrictive relay,'and a still more restrictive relay each of which relays corresponds with a particular code and picks up on receipt of its code to remove its restriction, means operative upon the absence of code to impose a most restrictive condition, a signal energized upon the imposition of saidmost restrictive condition, a manual contactor, a slow release, acknowledging relay energizable by the contactor in the absence of code to deenergize the signal, and an energizing circuit for each of the restrictive relays including a back point of the acknowledging relay.

19. In a'train control system, in combination, a car carried receiver positioned to receive coded train control energy, variously coded to produce different degrees of restriction on train operation, from the trackway, decoding means distinctively responsive to the variously coded energy in the receiver and to the absence thereof, the decoding means including a least restrictive relay, a medium restrictive relay and a more restrictive relay, each of which relays corresponds to a particular one of said codes and picks up on receipt of its code to remove its restriction, pick-up'energizing circuits for the restrictive relays, and means making the circuit for the medium restrictive relay more sensitive when its code is preceded by the code of the least restrictive relay than when preceded by that of the more restrictive relay, thus to facilitate changes to more restrictive conditions andimpede those to less restrictive conditions.

20. In a train control system, in combination, a car carried. receiver positioned to receive train control energy, variously coded to produce different degrees of restriction on train operation, from the trackway, decoding means distinctively responsive to the variously coded energy in the receiver and to the absence thereof, the decoding means including a least restrictive relay, a medium restrictive relay and a more restrictive relay, each of which corresponds to a particular one of said codes and which picks up on receipt of its code to remove its restriction, pick-up energizing circuits for the restrictive relays, and means making the circuit for the medium restrictive relay more sensitive when its code is preceded by the code of the least restrictive relay than when preceded by that of the more restrictive relay, thus to facilitate changes to I more restrictive conditions and hinder those to

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